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| EXTENDED ABSTRACTS |
Click here
to see the schedule of invited and oral presentations. |
| INDEX |
| The first letter of the presentation tag corresponds to
the presentation topic and the second to the presentation type, so AI-02
tags the second invited talk of Topic A, BP-03
the third oral presentation of Topic B and GP-01
the first poster presentation of Topic G. |
| Jump to Topic |
| OPENING KEYNOTE LECTURE |
 KN 01. How the
Laser Came to Be |
| A.E. Siegman Stanford University, USA |
| At this point it is almost 50 years since the first laser was operated; approaching 60 years since its predecessor, the first microwave maser, was conceived and operated; and close to 100 years since the stimulated emission concept was first proposed. This talk will look back at the important physical ideas and people involved in the early development of masers and lasers, leading to the "Maser Era" of 1950s, the dramatic explosion of laser technology that followed Maiman's first ruby laser in May 1960, and the immensely productive developments in this field that continue even today. |
| A. GAS AND CHEMICAL LASERS |
|
AI 01. COIL Radiation
of High Brilliance |
| J. Handke DLR, Institute of Technical Physics, Germany |
| High brilliance performance of chemical oxygen iodine lasers (COIL) requires resonator concepts that enable efficient power extraction from a low gain medium while the beam quality is close to the diffraction limit. Different resonator concepts are pre-evaluated by numerical methods and the promising candidates are adapted to a 10 kW-class COIL system. Theoretical predictions and experimental results are found to be in excellent agreement. The beam quality of different resonator architectures is evaluated by standards reported in literature. |
|
AI 02. Evolution
and Status of a Multi-Kilowatt Electric Iodine Laser Effort |
| A.E. Hill Texas A&M University and Plasmatronics, Inc., USA |
| Plasmatronics’ controlled avalanche-based electric oxygen iodine generator achieves 30% conversion from O2 into O21Δ at 40-50% electrical pump efficiency, wherein 2400 watts is imparted into the O21Δ flow stream. A special I2 disassociation-combined ejector mixing scheme has been developed in our quest to realize kW-class extraction from a 20 cm-wide, Mach 2.5, laser channel. Latest results of gain and output power measurements will be presented. |
|
AI 03. Three
Dimensional Simulation of Gas-Radiation Interactions in Chemical Oxygen-Iodine
Lasers |
| T. Madden US Air Force Research Laboratory, Directed Energy Directorate, USA |
| The interaction between an optical field and the atoms and molecules in a gas laser is examined from the standpoint of lineshape analysis and fluorescence. Both provide information regarding fluid dynamic structure and thermodynamic state that is useful for the development of gas lasers. These physics are examined from the context of 3-D, time-dependent solutions of the Navier-Stokes equations for non-reacting and reacting flow conditions relevant to chemical oxygen-iodine lasers. Implications for spectroscopic lineshape analysis and experimental validation of theoretical models are discussed. |
|
AI 04. High-Power
Chemical Lasers (HPCL): Gas dynamics Problems of Mobile System Operation
|
| A. S. Boreysho, V. M. Malkov
and A. V. Savin Laser Systems Ltd, Russia |
| The main gas dynamics problems of HPCL development are discussed shortly. The creation methodology of Pressure Recovery System (PRS) for Supersonic chemical lasers and ways of increasing PRS efficiency are examined. Problems of Exhaust Supersonic Diffuser, Supersonic Ejector operation and question of PRS start process are investigated in details. |
|
AI 05. Overview
of the US Air Force Research Laboratory Work in Lasers and Optics
|
| S.J. Thornton Air Force Research Laboratory, USA |
| The Directed Energy Directorate of the Air Force Research Laboratory is the United States Air Force’s center of excellence for directed energy technology. The Directorate operates on 4,325 acres of land with over 860,000 square feet of laboratory and office space. In addition to the numerous state-of-the-art research laboratories and testing structures at Kirtland Air Force Base in New Mexico, unique facilities include the Starfire Optical Range (SOR) at Kirtland, a testing site at the U.S. Army’s White Sands Missile Range in New Mexico, and the Air Force Maui Optical & Supercomputing Site (AMOS) in Hawaii. This presentation addresses the overall efforts of the laboratory in laser and beam control research. Included will be high energy gas and electric lasers and low energy semiconductor lasers. Advanced optics, testing facilities, and modeling/simulation will also be discussed. |
|
AO 01. Analysis
of Subsonic COIL Performance with a Magnetic Modulation |
| J. Beránek and K. Rohlena Institute of Physics, Academy of Sciences of the Czech Republic, Czech Republic |
| 1D subsonic COIL model with a mixing length was generalized to include the influence of a variable magnetic field on the stimulated emission cross-section. The results are compared with the measured pulse shape. |
|
AO 02. Advanced
Kinetic Package for COIL |
| S.Yu. Pichugin, V.N.
Azyazov and M.C. Heaven P.N. Lebedev Physical Institute of RAS, Samara Branch, Russia |
| An advanced kinetic package for COIL is proposed. The standard kinetic package was revised by adding processes describing the vibrational excitation and relaxation kinetics of I2 and O2. A multi-pathway I2 dissociation mechanism and new kinetic data are key elements of the advanced kinetic package. |
|
AO 03. RF Discharge
Slab Carbon Monoxide Laser: Overtone Lasing (2.5 – 4.0 micron) and Fundamental
Band Tuning (5.0 – 6.5 micron) |
| A.A. Ionin, A.Yu. Kozlov,
L.V. Seleznev and D.V. Sinitsyn Lebedev Physical Institute of Russian Academy of Sciences, Russia |
| Overtone lasing within the spectral range ~2.5 - 4.0 micron on ~80 spectral lines and fundamental band tuning over the spectral range ~5.0 – 6.5 micron on ~100 spectral lines was for the first time obtained in a slab carbon monoxide laser. Average output power of the compact repetitively pulsed RF discharge slab overtone CO laser came up to 0.3 W. |
|
AO 04. Influence
of Nitrogen Oxides on Singlet Delta Oxygen Production in Pulsed Electric Discharge
for Oxygen-Iodine Laser |
| A.A. Ionin, Yu.M. Klimachev,
A.A. Kotkov, A.Yu. Kozlov, I.V. Kochetov, A.P. Napartovich, O.A. Rulev, L.V. Seleznev, D.V. Sinitsyn, N.P. Vagin and N.N. Yuryshev Lebedev Physical Institute of Russian Academy of Sciences, Russia |
| Experimental and theoretical study of influence of nitrogen oxides NO and NO2 admixtures in oxygen containing gas mixture excited by pulsed electron-beam sustained discharge on input energy and time behavior of singlet delta oxygen (SDO) luminescence was carried out. Temperature dependence of the constant of SDO relaxation by unexcited molecular oxygen was estimated. |
|
AO 05. Achievement
of Positive Gain in the Amine-Based All Gas-Phase Iodine Laser System
|
| T. Masuda, T. Nakamura,
M. Endo and T. Uchiyama Dept. of System Design Engineering, Faculty of Science and Engineering, Keio University, Japan |
| Numerical simulation and flow-tube experiments are conducted to understand the chemistry of the amine based all gas-phase iodine laser (AGIL). We find that the key reactions to achieve positive gain are the deactivation reaction of excited I by Cl and the self annihilation reactions of NCl(1Δ). The order of the injection nozzles is crucial to suppress these reactions. A small signal gain of 0.01 %/cm is achieved by the new nozzle arrangement. To our knowledge, this is the first time achievement of positive gain of the amine-based AGIL system. |
|
AO 06. Supersonic
COIL Driven by Centrifugal Bubbling SOG with Efficient Depletion of Chemicals
in Single Pass |
| V.D. Nikolaev, M.I. Svistun, M.I. Khvatov and M.V.
Zagidullin Lebedev Physical Institute, Samara Branch, Russia |
| A centrifugal bubbling SOG generated gas at 100 torr of total pressure with efficient depletion of chemicals in one pass. A 1 kW class ejector COIL powered by this SOG demonstrated a specific power of 12.5 W per 1 cm3/s of BHP volumetric rate at chemical efficiency 22.7%. |
|
AO 07. Properties
of a DC Glow Discharge Iodine Atom Generator |
| V.N. Azyazov, P.A.
Mikheyev, M.V. Vorobyov and N.I. Ufimtsev P.N. Lebedev Physical Institute of RAS, Samara Branch, Russia |
| Iodine atoms recombination in a dc glow discharge generator was studied using Laser Induced Fluorescence (LIF) method. Up to 80 % of iodine flow consisted of iodine atoms. |
|
AO 08. Systematic
Technology Development of the Electric Oxygen-Iodine Laser |
| D.L. Carroll, G.F.
Benavides, J.W. Zimmerman, B.S. Woodard, A.D. Palla, J.T. Verdeyen and W.C. Solomon CU Aerospace, USA |
| A systematic approach to experiments and modeling have led to improvements in the hybrid Electric Oxygen-Iodine Laser (ElectricOIL) system that significantly increased the discharge performance, supersonic cavity gain, and laser power output. The cw laser operating at 1315 nm was pumped by the production of O2(a1Δ) in a radio-frequency (RF) discharge in an O2/He/NO gas mixture. A gain of 0.17% cm-1 and a laser power of 12.2 Watts were measured. Simulations with the BLAZE-IV model are in good agreement with laser gain data. |
|
AO 09. Fullerene-Oxygen-Iodine
Laser (FOIL). The Problem of Singlet Oxygen Generator with Optical Pumping of
Fullerenes (State-of-Art) |
| O.B. Danilov, I.V.
Bagrov, I.M. Belousova, V.M. Kiselev, T.D. Murav’eva and E.I. Sosnov SIC “Vavilov State Optical Institute”, Institute for Laser Physics, Russia |
| The outlook of Singlet Oxygen Generator (SOG) with optical pumping of fullerene solution (or suspension) using the principle of the centrifugal bubbling apparatus is considered. Scheme of fulleren-oxygen-iodine laser (FOIL) with such a SOG is discussed. |
|
AO 10. A Microwave-Pumped
Planar CO2-Laser |
| A.P. Mineev, S.M. Nefedov
and P.P. Pashinin A.M. Prokhorov General Physics Institute, RAS, Russia |
| The radiation parameters of a diffusion-cooled compact planar CO2-laser pumped by microwave discharge at a frequency of 2.45 GHz are studied. An average output power of 25 W and an efficiency of ~13% are obtained. A peak output power of 580 W is achieved for 20-us pulses emitted at a pulse repetition rate of 400 Hz. The dependence of parameters of the CO2-laser on the input pulse power in the range 0.8-8 kW, the composition and pressure of the working mixture and the pump pulse duration and repetition rate are studied experimentally. |
|
AO 11. Experimental
Modeling the Active Medium of a Pulsed DOIL with Volume Generation of Iodine Atoms
|
| N. Vagin and N. Yuryshev P.N. Lebedev Physics Institute of Russian Academy of Science, Russia |
| The active medium of a pulsed DOIL with volume generation of iodine atoms was experimentally simulated using the chemical generator of singlet oxygen and MW discharge to understand the feasibility of a pulsed oxygen-iodine laser with electrical generator of singlet oxygen. |
|
AO 12. Studies
of Supersonic COILs at Ben-Gurion University: (1) Experiments on 10-cm Gain-length
Device. (2) Computational Fluid Dynamics Modelling |
| I. Brami-Rosilio, K. Waichman, B.D. Barmashenko and S.
Rosenwaks Department of Physics, Ben-Gurion University of the Negev, Israel |
| Following the achievement of a 40% chemical efficiency in a supersonic 5-cm gain-length chemical oxygen-iodine laser (COIL), experimental studies on a 10-cm gain-length device are reported. It is envisaged that higher efficiency may be achieved in this device. Also reported are results of three-dimensional (3D) computational fluid dynamics (CFD) modeling of the gain in an ejector COIL. |
|
AO 13. RF Discharge
Generation of I Atoms in CH3I and CF3I for COIL/DOIL
|
| J. Schmiedberger, V.
Jirásek, M. Censký, J. Kodymová, I. Picková and O.
Špalek Institute of Physics, Academy of Sciences CR, Czech Republic |
| Experimental results of radiofrequency discharge generation of atomic iodine in CH3I and CF3I for a supersonic COIL/DOIL are presented. Measurements of atomic iodine concentration distribution in the supersonic flow field and their dependence on basic RF discharge parameters and flow mixing conditions are included and compared. |
|
AO 14. Metal
Vapor Lasers with Modified Kinetics Pumped by a Capacitively Coupled Discharge
|
| F.A. Gubarev, G.S.
Evtushenko, V.B. Sukhanov and V.F. Fedorov Institute of Atmospheric Optics, Siberian Branch of Russian Academy of Sciences, Russia |
| The paper presents the results of experimental study of CuBr+Ne+HBr – laser excited by a capacitively coupled discharge. It is shown that capacitive discharge can be successively applied for pumping of lasers on self-terminated transitions in metal vapors including metal vapor lasers with modified kinetics. |
|
AO 15. Efficient
Discharge Lasers Pumped by Generators with Inductive Energy Storage
|
| A.N. Panchenko, V.F.
Tarasenko and A.E. Tel'minov High Current Electronics Institute, Russia |
| Results of investigation of different gas lasers pumped by the inductive energy storage (IES) generator obtained during the last two years are reported. It was shown that the generator allows to form long-lived stable discharge in the laser mixtures. As a result, pulse duration, output energy and efficiency of the lasers under study were improved. |
|
AO 16. Double-Pass
Hybrid Resonator for COIL |
| C. Pargmann, T. Hall,
F. Duschek, K.M. Grünewald and J. Handke German Aerospace Center (DLR), Institute of Technical Physics, Langer Grund, Germany |
| Based on the experiences made with a negative branch hybrid resonator (NBHR) a double-pass configuration of the NBHR for a 10 kW-class Chemical Oxygen Iodine Laser (COIL) is investigated. Next to estimations about the alignment sensitivity measurements of intensity and phase of the near and the far field are performed. The results are compared to calculations done with the help of the Fresnel-Kirchhoff theory. |
|
AO 17. Powerful
TEA Laser on Electronic IR Transitions of Rare Gases |
| V.O. Petukhov and V.A.
Gorobets B.I. Stepanov Institute of Physics of NASB, Belarus |
| The goal of this work is the show of the prospects for a simple TEA laser excited by self-sustained discharge the same as a typical TEA CO2 laser for generation of powerful pulses in rare gases (Xe, Kr, Ar, Ne) on IR electronic transitions. For this purpose the optimization of power and spectral parameters of such laser has been carried out. In result powerful lasing on about 15 lines in the range of 1 – 4 microns with output energy on stronger of them has been achieved >10 mJ (peak power >0.2 MW). |
|
AO 18. High-Power
CO Laser with RF discharge for Isotope Separation Employing Condensation Repression
|
| I.Ya. Baranov Baltic State Technical University, Russia |
| The way of transfer from CO small-scale device to CO laser for isotope separation is proposed. The calculation model scaling of CO laser with RF discharge in supersonic flow with cooling by its expansion in the nozzle is developed. |
|
AO 19. Centrifugal
Spray Generator of Singlet Oxygen for a COIL |
| O. Špalek, V.
Jirásek, M. Censký, J. Kodymová, I. Picková and J.
Hrubý Dept. of Chemical Lasers, Institute of Physics, Academy of Sciences CR, Czech Republic |
| Results of an experimental study of a new type of singlet oxygen generator for the Chemical Oxygen-Iodine Laser are presented. This spray generator with a centrifugal separation of liquid can be used at extremely high generator pressures from 40 kPa to 80 kPa. |
|
AO 20. Gain Optimization
and Scaling of a Pulser-Sustainer Discharge Excited Oxygen-Iodine Laser
|
| J. Bruzzese, M. Nishihara, A. Hicks, W.R. Lempert, J.W.
Rich and I.V. Adamovich Department of Mechanical Engineering, The Ohio State University, USA |
| The paper discusses optimization of gain and output power and scaling of a pulser-sustainer discharge excited oxygen-iodine laser using adding NO to the laser mixture, iodine vapor disscociation in an auxiliary side discharge, and scaling of the pulser-sustainer discharge volume and power. |
|
AO 21. Singlet
Oxygen Generators – The Heart of Chemical Oxygen Iodine Lasers: Past, Present and Future |
| K.B. Hewett Air Force Research Laboratory, Directed Energy Directorate, USA |
| Since the initial demonstration of chemical oxygen iodine lasers in 1977, researchers have realized that the heart of the COIL system is the singlet oxygen generator. This drives the performance of the system in terms of output power, mass efficiency, engineering complexity, reliability and maintainability. For this reason the singlet oxygen generator has been the focus of intense research and development efforts over the last 30 years. This paper reports on the history of singlet oxygen generators – starting with the simple sparger design used in the initial COIL demonstration and ending with current jet or droplet generators used in laboratories around the world. The relative performance of the different generator types will naturally lead to performance goals for the research efforts of the future. |
|
AO 22. A Real-Time
On-Line Measurement of Iodine Flow Rate Based on Absorption Spectroscopy
|
| G. Li , F. Sang and
L. Duo Dalian Institute of Chemical Physics, China |
| Iodine flow rate (IFR) measurement is an essential diagnostic tool in the research and optimization of chemical oxygen-iodine laser (COIL) system. Venturi meter and absorption spectroscopy was used to monitor IFR. But it is difficult for Venturi meter to precisely measure IFR. Simple absorption spectroscopy has trouble monitoring IFR due to the contamination on diagnostic windows. An advanced absorption spectroscopy for measuring IFR was described in this paper. It can easily eliminate the influence of the contamination on IFR measurement and obtain a precise IFR. The method has been used in COIL. |
|
AO 23. Scalable
Chemical Oxygen-Iodine Laser |
| B.A. Vyskubenko, A.A.
Adamenkov, V.V. Bakshin, L.A. Vdovkin, S.D. Velikanov, S.G. Garanin, S.V. Grigororvich,
S.P. Ilyin, R.I. Il’kaev, Yu.N. Ilyushin, A.M. Kalashnik, Yu.V. Kolobyanin,
E.A. Kudryashov, M.L. Leonov, V.B. Moiseev, V.V. Svishchev and M.V. Troshkin Russian Federal Nuclear Center - VNIIEF, Russia |
| COIL designed around the generally accepted layout is shown to be scalable on the condition of the velocity in its reaction zone being no less than 50–70 m/s. The twisted-aerosol singlet oxygen generator (TA SOG) meeting this requirement is described. |
|
AO 24. Multiphase
Reacting Flow Modeling of Singlet Oxygen Generators for Chemical Oxygen Iodine Lasers |
| L.C. Musson, R.P. Pawlowski,
A. Salinger, T. Madden and K. Hewett Sandia National Laboratories, USA |
| Singlet oxygen generators are multiphase flow chemical reactors used to generate energetic oxygen to be used as a fuel for chemical oxygen iodine lasers. In this paper, a theoretical model of the generator is presented along with its solutions over ranges of parameter space and oxygen maximizing optimizations. |
|
AO 25. Development
of a Picosecond CO2 Laser System for a High-Repetition γ-Source
|
| M.N. Polyanskiy, I.
Pogorelsky, V. Yakimenko and V.T. Platonenko Brookhaven National Laboratory, USA |
| The concept of a high-repetition-rate, high-average power γ-source is based on Compton backscattering from the relativistic electron beam inside a picosecond CO2 laser cavity. Proof-of-principle experiments combined with computer simulations allow evaluating the promise of this approach for novel applications in science and technology. |
|
AO 26. Alkali
Lasers |
| R. Knize and B. Zhdanov US Air Force Academy, Laser and Optics Research Center, USA |
| Alkali vapor lasers are a new type of gas lasers, developed during the last several years. These lasers have potential for very important applications. In this paper we present a review of our main results and recent achievements in alkali laser development, discuss some possible applications of these lasers. |
|
AP 01. Experimental
Study on the Surface Discharge Optical Pumping Source with High Repetition Mode |
| L. Yu, X. An, L. Ma,
A. Yi, F. Zhu, C. Huang and J. Liu Northwest Institute of Nuclear Technology, Shannxi Province, China |
| A surface discharge optical pumping source module with high repetition mode is described. The maximum pulse repetition rate is up to 90 Hz. The electrical and radiative properties of the optical pumping source have been studied. The equivalent resistance and inductance, the maximum current and the deposition efficiency of the discharge circuit under various distance of electrodes have been compared. |
|
AP 02. Study
of COIL Active Medium with Atomic Iodine Generated via Fluorine Atoms
|
| V. Jirásek,
O.Špalek, M. Censký, J. Kodymová, I. Picková and I.
Jakubec Institute of Physics, v.v.i., Academy of Sciences, Czech Republic |
| A generation of atomic iodine via F atoms with their immediate injection to the supersonic COIL nozle has been studied. Very high concentrations of I atoms were obtained in the laser cavity in the absence of O2(1Δg). Low values of small signal gain measured in the O2(1Δg) flow did not correspond to high efficiency of I generation. This was ascribed to O2(1Δg) quenching by DO2 radical. |
|
AP 03. Investigation
of Gold Catalyst Influence on the Radiation Efficiency of Slab CO2
Laser |
| A.I. Dutov, N.L. Orlov,
A.A. Sokolov and E.A. Zobov ZAO “RLS”, Russia |
| The paper presents the results of experimental investigation of output power radiation and efficiency of RF-excited sealed-off slab CO2 laser. The efficiency up to 19-20% was obtained in the range of 200 W to 360 W of output laser power. |
|
AP 04. Study
of Energy and Time-Depending Characteristics of Pulse-Periodic Oxygen-Iodine Laser
|
| S.D. Velikanov, V.G. Gorelov, I.V. Gostev, V.V. Kalinovsky,
I.A. Komissarov, V.V. Konovalov, I.V. Konovalov, V.N. Mikhalkin, V.D.
Nikolaev, I.V. Sevryugin, A.V. Smirnov, R.E. Sobolev and L.N. Shornikov Russian Federal Nuclear Centre – All-Russian Research Institute of Experimental Physics, Russia |
| In [1-3] there was investigated the residual chlorine influence on the parameters of pulse generation of chemical oxygen-iodine laser (COIL). It’s impossible to achieve 100% of the chlorine utilization without essential deactivation of singlet oxygen in the reactor of the singlet oxygen generator (SOG) that is a constituent part of COIL. Under natural conditions, that’s why residual chlorine is always present at the exit of the SOG. |
|
AP 05. Self-Pulsing
Instabilities in Fast-Flow Gas Lasers |
| L.S. Kouzminsky, A.I.
Odintsov and A.I. Fedoseev Dept. Physics, Lomonosov Moscow State University, Russia |
| Perturbation exchange processes in two-component active medium such as CO2-N2 gas mixture were shown to be a significant factor determined the threshold of self-pulsing oscillations in FFL. Analytical expressions allowed to define increments and frequencies of the oscillations on the base of stationary lasing parameters were obtained. |
|
AP 06. The Experimental
Research of the RF Discharge in O2 and its Mixtures |
| X. Zhang, X. Wang and
G. Li Institute of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, China |
| A 45 MHz RF discharge was obtained in pure O2 and its mixtures, the discharge cross-section is 5×5 mm2 and length is 400 mm. To study the influences of discharge parameters on electron energy, a Langmuir probe system was set up. And the intensity of oxygen atom at 777.19 nm was used to investigate the decomposition of the O2 in the RF discharge. |
|
AP 07. Optimisation
of Characteristics of a CW Chemical HF Laser with a New Method for Oxidizing Gas Production |
| I.A. Fedorov, V.K.
Rebone, Yu.P. Maksimov, V.A. Mitryaev, N.E. Tret’yakov and A.L. Etsina Russian Scientific Center «Applied Chemistry», Russia |
| The energy parameters of an supersonic cw chemical HF laser operating by using a new method for oxidizing gas production, which is based on the principle of two–zone mixing, are optimised. The total amount of the inert diluent (helium) supplied to the laser was varied during experiments by varing its relative fraction only in the second mixing zone (in subsonic parts of the nozzles). In the first mixing zone (in gas generator) its relative fraction was constant. |
|
AP 08. 15 J/l
Energy Density from a TEA CO2 Laser with Four Preionization Circuits
|
| A. Lorusso, V. Nassisi,
A. Rainò, M.V. Siciliano, L. Velardi and M. Rosano Dept. of Physics, University of Salento, LEAS Laboratory, Italy |
| A new transverse electric atmospheric laser by four very compact preionizator circuits was made. It was able to generate a volumetric energy density of 15 J/l with a pulse time duration of about 30 ns. The output energy behaviour was studied by a plane parallel cavity on total pressure value and on the total laser shots. The uniformity of the output beam was not excellent while its divergence was very low. By this laser we treated samples of polymers useful in bio-medical fields. |
|
AP 09. A Computational
Fluid Dynamics Simulation of a High Pressure Ejector COIL and Comparison to Experiments
|
| K. Waichman, B.D. Barmashenko
and S. Rosenwaks Department of Physics, Ben-Gurion University of the Negev, Israel |
| Comparing the results of three-dimensional computational fluid dynamics model calculations to available experimental results, we show that the model is applicable to high pressure, ejector type chemical oxygen-iodine laser (COIL), reasonably reproducing the measured gain, temperature and gas velocity. |
|
AP 10. Analysis
of Lasing in COILs with Positive and Negative Branch Unstable Resonators Using
a Simple Geometrical-Optics Model |
| B.D. Barmashenko Department of Physics, Ben-Gurion University of the Negev, Israel |
| A simple geometrical optics model is developed that describes the power extraction in chemical oxygen-iodine lasers with unstable resonators. The off-axis positive and negative branch unstable resonators with cylindrical mirrors that were recently used in the COIL are studied. The optical extraction efficiency and intensity spatial distributions in the flow direction for both kinds of resonators are calculated. |
|
AP 11. Evaluation
of High-Repetition-Rate Excitation Discharge in TEA Gas Laser with Supersonic Gas Flow |
| G. Imada, T.T. Son,
M. Suzuki and W. Masud Department of Electrical Engineering and Extreme Energy-Density Research Institute, Nagaoka University of Technology, Japan |
| A double-pulse discharge method is used to simulate a high-repetition-rate excitation discharge in TEA gas laser with supersonic gas flow. In the gas flow with a Mach number M = 2.0, not only heated column but also shock wave produced by the former discharge has a key effect on stability of the subsequent discharge. A formula for estimating the maximum repetition rate of stable discharge in supersonic gas flow is proposed. |
|
AP 12. Initial
Development of Hybrid Plasma Jet Generator of O2(1Δ)
for DOIL |
| J. Schmiedberger, K.
Rohlena, P. Filip, J. Gregor, M. Hrabovský, P. Krenek, V. Jirásek
and J. Kodymová Institute of Physics, Academy of Sciences CR, Czech Republic |
| The initial stage in development of hybrid plasma jet generator of singlet oxygen for DOIL is presented. This novel type of generator is based on a fast mixing of hybrid argon plasma jet of DC electric arc and radio-frequency discharge with a neutral molecular oxygen stream. Key features of physical and technical design are included in this paper. |
|
AP 13. Impulse-Periodical
HF (DF) – Laser of Atmospheric Pressure with Impulse Repetition Frequency Up to 2200 Gz |
| S.D. Velikanov, P.A.
Yevdokimov, A.F. Zapolskii, B.E. Kodola, D.V. Sokolov and E.D. Yakovlev Russian Federal Nuclear Centre – VNIIEF, Russia |
| The aim of the present work is to define ways of reaching limit initiation frequencies. According to this point the present work is supposed to solve this problem and continues the previously published investigation results [Butsykin I.L. et al. Quantum Electronics 31, 957-961 (2001); Velikanov S.D. et al., Quantum Electronics 24, 11-14, (1997)]. |
|
AP 15. On Output
Power of Fast-Flow CO2-Laser |
| V.V. Nevdakh B.I. Stepanov Institute of Physics of NASB, Belarus |
| The role of the selectivity of pumping, excitation rate of the upper and relaxation time of the lower laser levels in obtaining the maximal output power of fast-flow CO2-lasers are discussed. The much higher output power of fast-flow CO2-laser compared with laser without a gas flow is caused by the larger excitation rate and saturation parameter and not by the gas cooling is shown. There is the own optimal temperature of the active medium to achieve the maximal output power of fast-flow CO2-laser is concluded. |
|
AP 16. Optical
Quality Control of Gas Flow Laser Active Mediums |
| S.Yu. Strakhov, A.V. Trilis, D.N. Vasil’ev and V.V.
Lobachev Laser systems Ltd., Russia |
| Features of active mediums (AM) forming in high power gas flow lasers (GDL, CWCL, COIL) are considered. The main common moments in the process of optical heterogeneous streams forming are determined. It’s shown that passive correction of AM heterogeneities allows decreasing level of phase aberrations. |
|
AP 17. Beam Parameters
Control and Increase of Chemical Oxygen-Iodine Laser Efficiency at Using of Unstable Resonator with a Hole-Coupled Mirror |
| A.S. Boreisho, A.V. Savin, S.Yu. Strakhov, A.V.
Trilis and V.V. Lobachev Laser Systems Ltd., Russia |
| The perspectives of unstable resonators with a hole-coupled mirror and injection of controlling beam for using in COIL are considered. It is shown that considerable increment of output power and brightness of laser beam can be achieved at using of such resonators. These resonators are especially important for medium-power oxygen-iodine lasers, where usual unstable resonators are not effective because of small magnification coefficients. It is possible to control COIL output beam parameters by using low-power injection of tunable semi-conductor laser with fiber amplifier. |
|
AP 18. Carbon
Monoxide Laser Emitting Nanosecond Pulses with 10 MHz Repetition Rate
|
| A.A. Ionin, Y.M. Klimachev,
A.A. Kotkov, A.Yu. Kozlov, L.V. Seleznev and D.V. Sinitsyn Lebedev Physical Institute of Russian Academy of Sciences, Russia |
| Actively mode-locked electron-beam-sustained-discharge CO-laser producing ~10 ns (FWHM) pulses following with repetition rate 10 MHz for both single-line and multiline mode of operation was experimentally studied. Specific output energy for multiline CO-laser mode of operation was up to 20 J/(l Amagat), the laser efficiency being 3.5%. |
|
AP 19. Analysis
of COIL Resonator Expanding Angle Design |
| L. Shouxian, Yu Zhen,
S. Xiaojian, D. Yanyi and D. Xiangwan Institute of Applied Physics and Computational Mathematics, China |
| The factors of Chemical Oxygen-Iodine Laser (COIL) resonator expanding angle design are analyzed in this paper. It is shown that the primary factor is the rate of the releasing heat from the near resonant energy transfer reaction between O2(1Δ) and I at the resonator entrance with the laser extracting. It is a characteristic of COIL that the rate of the releasing heat with lasing is bigger than without lasing. A slightly bigger resonator expanding angle than that of constant pressure operating condition is sufficient to avoid the shock wave appearance. |
| B. SOLID STATE, DISK AND FIBER LASERS |
|
BI 01. High Energy
Laser Development for the Joint Technology Office |
| M. Neice HEL JTO, USA |
| The High Energy Laser Joint Technology Office (HEL-JTO) was established in 2000 for the purpose of developing and executing a comprehensive investment strategy for HEL science and technology that would underpin weapons development. Recent progress in diode-pumped solid-state lasers has significantly enhanced the performance of solid-state lasers for higher efficiency and higher average power output. The high reliability and high efficiency of diode pumped lasers make them attractive for a variety of military applications. The progress of Nd:YAG solid state lasers in the multi-tens of kilowatts power range with good beam quality is presented in this presentation. |
|
BI 02. Recent
Progress in Pulsed Fiber Lasers for Materials Processing and Remote Sensing
|
| J.R. Salcedo Multiwave Photonics, Portugal |
| Specially designed Pulsed Fiber Lasers based on a MOPA (Master Oscillator Power Amplifier) architecture now allow optical pulse shaping and pulses on demand, greatly extending the flexibility provided to the user in the context of materials processing as well as LIDAR and remote sensing. |
|
BI 03. Hollow
Dielectric Waveguides and Index Antiguided Fibers: Old Technology Made New
|
| A. Siegman Stanford University, USA |
| To be provided. |
|
BO 01. SBS Mitigation
with ‘Multi-Tone’ Amplification – A Theoretical Model
|
| T.J. Bronder, I. Dajani, C.M.
Zeringue, C.A. Robin and T.M. Shay Air Force Research Laboratory, High Power Solid State Lasers Branch, USA |
| A novel technique for mitigating stimulated Brillouin scattering (SBS) in gain fiber through seeding by two master oscillators is extended to three seed signals. This ‘multi-tone’ amplification uses more than one master oscillator signal where the relatively large frequency separation of the signals (10’s of GHz – THz) allows each ‘tone’ to reach its SBS threshold nearly independently and thus increases the overall nonlinear threshold by a factor of 2 (for two input signals) or 3 (for three inputs) in the amplifier. We report the first theoretical model for such a fiber amplifier system that simultaneously solves for the amplified signal, SBS, and four wave mixing (FWM) intensities. The details of the model and specific results – such as the optimum frequency separation, increase in the SBS threshold, and FWM – are also discussed. |
|
BO 02. Aberration-Free,
Rod-Based Amplifier-Modules for High Average-Power Lasers |
| S. Jackel, Y. Lumer,
S. Rosenberg, D. Rubin, I. Moshe, A. Meir, G. Machavariani and R. Lavi Nonlinear Optics Group, Soreq NRC, Israel |
| We show that the high average-power lasers with good beam quality can be built based on rod-shaped elements. The key concepts to achieve this breakthrough are radially polarized light, pump-chambers that produce no azimuthal aberrations and only controlled amounts of spherical aberration, and simple aberration correction elements. In this paper we show how to design multi-kW pump-chambers required in aberration-free amplifier modules. |
|
BO 03. Frequency
Shifting of High Power Laser Radiation by Stimulated Raman Scattering in Crystals
|
| H.J. Eichler, H. Rhee,
V.A. Orlovich and V.A. Lisinetskii Institute of Optics and Atomic Physics, Technische Universität Berlin, Germany |
| Stimulated Raman scattering (SRS) has been observed in more than 100 crystals generating about 2000 different wavelengths covering the ultraviolet, visible and infrared spectral regions with a mean spacing of 1 nm. Barium nitrate crystals have been used to demonstrate high Raman shifted output energy up to 156 mJ or high average power of 10 W at 1.197 µm, 1.369 µm and 1.599 µm wavelengths with quantum efficiencies of up to 66%. |
|
BO 04. Power
Scale-Up in Good Beam-Quality Radially-Polarized Rod-Based Lasers
|
| I. Moshe, S.
Jackel, Y. Lumer, A. Meir and Y. Paiken Nonlinear Optics Group, Soreq NRC, Israel |
| In this work we present a path to scale-up in the power of good beam-quality radially-polarized solid-state lasers. Beam-quality degradation and depolarization must be minimized in the power amplifier chain. We present the performance of our power amplifier module that add >1.5 kW to the laser beam with only a very low beam-quality degradation of ΔM2= 1.5 and with excellent polarization maintenance. |
|
BO 05. 573 nm
External Cavity CVD-Diamond Raman Laser |
| R.P. Mildren, J.E.
Butler and J. Rabeau MQ Photonics Research Centre, Macquarie University, Australia |
| We report an external cavity Raman laser based on a single diamond crystal grown by chemical vapour deposition. When pumped with 10ns pulses of 532nm, output pulse energies up to 0.2 mJ were obtained at 573 nm with a slope efficiency of conversion of 18%. |
|
BO 06. High-Energy,
Diode-Pumped Ytterbium-Based Chirped-Pulse Amplifier |
| M. Siebold, J. Hein,
C. Wandt, S. Klingebiel, Z. Major, S. Trushin, I. Ahmad, T.-J. Wang, S. Karsch
and F. Krausz Max-Planck-Institute for Quantum Optics, Germany |
| A diode-pumped chirped-pulse amplifier system based on Yb:glass and Yb:YAG as a picosecond pump source for an ultra-high peak-power optical parametric chirped-pulse amplifier has been developed. When operating at nanosecond pulses a maximum output pulse energy of 2.9 J and a maximum average output power of 15 W have been achieved. At a small-signal gain of 103 in Yb:YAG the seed pulse bandwidth of 4 nm (FWHM) has been gain-narrowed to 2.5 nm, which allows the re-compression to < 1 ps. |
|
BO 07. Hybrid
Ytterbium-Neodymium Laser Chain and Scalability to Petawatt Peak Powers
|
| J. Wemans, C.P. João
and G. Figueira Grupo de Lasers e Plasmas, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Portugal |
| We present here the experimental results of a hybrid ytterbium-neodymium laser chain. A nanosecond, multi-millijoule amplifier based on Yb-doped materials and diode pumping is used as a high energy and high repetition rate seed for a Nd:glass laser chain. Wavelength tunability, choice of Yb-doped material and scalability are also addressed by means of a simulation code. |
|
BO 08. Tunable
Nd:GSAG Laser Around 943 nm for Water Vapor Detection |
| F. Kallmeyer, X. Wang
and H.J. Eichler Institute of Optics and Atomic Physics, Technische Universität Berlin, Germany |
| A Nd:GSAG laser operated at the 4F3/2 → 4I9/2 transition was tuned by a FPI-etalon achieving a tuning range of 1.5 nm with a center wavelength at 942.7 nm. Three water vapor absorption wavelengths confirmed by the ESA as suitable for a water vapor DIAL with different absorption strength are within this tuning range. Lasing could be achieved at all three wavelength. |
|
BO 09. Status
of Prototype of SG-III High-Power Solid-State Laser |
| Y. Haiwu, J. Feng,
W. Xiaofeng, Z. Wanguo, Z. Xiaomin, S. Zhan, L. Mingzhong, H. Dongxia, H. Shaobo,
P. Zhitao, F. Bin, Z. Hai, G. Liangfu, L. Xiaoqun, S. Jingqin, Z. Runchang, Y. Dong, Z. Kuixing and Y. Xiaodong Research Center of Laser Fusion, China Academy of Engineering Physics, China |
| We are currently developing a large aperture neodymium-glass based high-power solid state laser, Shenguang-III (SG-III), which will be used to provide extreme conditions for high-energy-density physical experiments in China. As a baseline design, SG-III will be composed of 48 beams arranged in 6 bundles with each beam aperture of 40 cm × 40 cm. A prototype of SG-III (TIL-Technical Integration experimental Line) was developed from 2000, and completed in 2007. TIL is composed of 8 beams (four in vertical and two in horizontal), with each square aperture of 30 cm × 30 cm. After frequency tripling, TIL has delivered about 10 kJ in 0.351 µm at 1 ns pulsewidth. As an operational laser facility, TIL has a beam divergence of 70 µrad (focus length of 2.2 m, i.e., 30DL) and pointing accuracy of 30 µm (RMS), and meets the requirements of physical experiments. |
|
BO 10. Phase-Locking
of Two Coupled Erbium Doped Fiber Ring Lasers |
| M. Fornalczyk, A. Budnicki and K.M.
Abramski Laser & Fiber Electronic Group, Institute of Telecommunications, Teleinformatics, Acoustic, Wroclaw Universisty of Technology, Poland |
| The phase-locking effect forced by mutual radiation coupling between lasers was investigated experimentally in two erbium doped ring fibre lasers. |
|
BO 12. Thermal
Limits on Solid State Laser Scaling |
| R.F. Walter, K.A. Truesdell,
J.F. Welch, S. Post and T. Madden Schafer Corporation, USA |
| This paper examines the tradeoffs which govern the relation between high power and good beam quality in solid state and fiber lasers. |
|
BO 13. High-Average
Power Disk Laser Face-Pumped by 2D-Stack Diode Arrays |
| C. Tang, Z. Yao, J.
Jiang, B. Tu, Z. Cai, H. Hu and K. Zhang Institute of Applied Electronics, CAEP, China |
| The progress in the development of the large-aperture Nd:YAG disk laser face-pumped by 2D-stack diode arrays was presented. Over 3kW average power with the beam quality less than 10 times diffraction limitation was achieved by adopting a conventional pumping optics designs and improving the technique of the gain medium mounting with the water cooler. |
|
BP 01. Experimental
Study of Face- and Edge-Pumped Ceramic Slab DPSSLs in the 100-500 W Power Range
|
| A. Lapucci, M. Ciofini,
M. De Rosa, E. Favilla, E. Sani and A. Rocco Istituto Nazionale di Ottica Applicata (C.N.R.), Italy |
| We developed several prototypes of ceramic Nd:YAG slab lasers pumped by different laser diode stacks. Compactness, efficiency and ruggedness have been the principal design drivers. Nevertheless beam quality and insensitivity to diodes temperature have also been pursued. An edge-pumped device with less than 12% power variation over a 20°C temperature range has been demonstrated. |
|
BP 02. Enhancement
of Efficiency Extracavity Conversion of Radiation to Harmonics - A Method of Spatial
Walk-Off Compensation in Crystals KTP and LBO |
| V.V. Kiyko, S.G. Grechin and E.N.
Ofitserov A.M. Prokhorov General Physics Institute Russian Academy of Science, Russia |
| Experimentally demonstrated is, that the spatial compensation of the second harmonics radiation walk-off with respect to beam of initial frequency, in the process of conversion into the third harmonics within sequentially placed LBO crystals, enables to increase conversion efficiency into the third harmonic - more than 3 times. |
|
BP 03. Numerical
Comparison of Pulse Amplification in Ytterbium-Doped Media |
| C.P. João, J.
Wemans, G. Figueira Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Portugal |
| We present a new amplification code that allows the realistic simulation of ytterbium-based regenerative or multipass amplifiers with a very broad range of input parameters. A regenerative amplifier is fully simulated with 3D modeling of the pump, population inversion, gain, thermal load and spectrum. These results were successfully benchmarked against our experimental data for several ytterbium-doped media. |
|
BP 04. Broadband
Frequency Tripling Based on Segmented Partially-Deuterated KDP Crystals
|
| F. Bin, H. Wei, L.
Fuquan, L. Keyu and W. Fang Research Center of Laser Fusion, China Academy of Engineering Physics, China |
| We report a novel frequency tripler for efficient conversion of broadband high power laser pulses at 1 µm. The tripler is composed of several segmented partially deuterated KDP with discrete values of deuteration. Deuteration level can be used as a degree of freedom to alter the phase-matching wavelength of a partially deuterated KDP crystal. The segmented partially deuterated KDP crystal is made by thermal bonding method. It has been shown that this new tripler is capable of enhancing the acceptance bandwidth of frequency tripling. A five-segment design is presented, which is applicable to the efficient frequency tripling of chirped pulses with a bandwidth of ~4-nm, and hence suitable for Nd:glass petawatt laser system. |
| C. UV & VUV LASERS |
|
CI 01. A Laser-Plasma
Clean Soft X-Ray Source for Projection Microlithography |
| S. Bollanti ENEA, Italy |
| Within a National Project on nanotechnologies, at the ENEA Research Centre in Frascati a micro-exposure tool for projection lithography at 14.4 nm has been developed. The laser-plasma soft X-ray source is equipped with a patented debris mitigation system developed in the frame of a European Integrated Project, in order to preserve the collecting optics. A 90-nm-resolution patterning has been achieved on resist by this laboratory-scale tool based on a Schwarzschild-type projection optics. Also results of fluorescent material exposures will be shown. |
|
CI 02. High Performance
DUV Lasers for Lithographic and other Industrial Applications |
| I. Fomenkov Cymer Inc., USA |
| This paper describes progress in the development of KrF and ArF excimer lasers toward the ever more challenging requirements of the semiconductor microlithography industry. Also included will be recent developments with the XeF excimer laser used in the display industry and high power CO2 lasers used in the production of 13.5nm radiation for next generation microlithography tools. |
|
CO 01. Long Term
Tests of Resonator Optics in ArF Excimer Lasers |
| Nils Beermann, Holger
Blaschke, Henrik Ehlers, Detlev Ristau, Dirk Wulff-Molder, Sigrid Jukresch, Ansgar
Matern, Claus F. Strowitzki, Andreas Görtler, Martin Bischoff, Dieter Gäbler
and Norbert Kaiser Laser Zentrum Hannover, Germany |
| Aim of the work is the optimization of the resonator optics of excimer laser systems to achieve longer lifetimes and reduced costs of ownership. Under high photon fluxes (typically 80 mJ/cm²) long-term tests of the resonator optics has been done in an ArF-excimer laser at 193 nm wavelength. Especially the degradation of the partially reflecting outcoupling mirror used as internal resonator has been investigated. The contamination and damage of the optics surfaces were analyzed. New special coatings have been successfully tested. |
|
CO 02. OFI Argon
Excimer Amplifier for Intense Subpicosecond VUV Pulse Generation |
| M. Kaku, S. Kubodera,
K. Oda, M. Katto, A. Yokotani, N. Miyanaga and K. Mima Dept. of Electrical and Electronic Engineering and Photon Science Center, University of Miyazaki, Japan |
| A subpicosecond VUV seed beam at 126 nm has been produced by nonlinear wavelength conversion of an infrared subpicosecond laser at 882 nm in rare gases. An optical-field-induced ionization (OFI) amplifier has been optimized to amplify the VUV seed beam. The amplifier itself has produced a gain-length product of more than six by using nonlinear plasma channeling observed in a high-pressure Ar amplifier medium. |
|
CO 03. Investigation
of E-Beam-Pumped Krypton Fluoride Laser towards a Viable Driver for Inertial Fusion
Energy |
| V.D. Zvorykin, S.V.
Arlantsev, R.V. Gaynutdinov, A.O. Levchenko, A.G. Molchanov, S.I. Sagitov, A.P.
Sergeev, P.B. Sergeev, D.B. Stavrovskii and N.N. Ustinovskii P.N. Lebedev Physical Institute of RAS, Russia |
| An overview of the research being carried out at e-beam-pumped Krypton Fluoride GARPUN laser system of Lebedev Institute in collaboration with the other Institutions is presented. It is emphasized the critical issues of KrF laser as an efficient and viable rep-rate driver for the Inertial Fusion Energy. The experimental data are the base for 3D numerical simulations predicting operation parameters of IFE-scale drivers. Testing of new UV optical materials and coatings resulted in the improved stability of laser windows against various adverse factors. |
|
CP 01. Harmonics
Generation in VUV Spectral Region Driven by a NIR Ti:Sapphire Laser in Rare Gases
|
| M. Katto, K. Oda, M.
Kaku, S. Kubodera, A. Yokotani, N. Miyanaga and K. Mima Cooperative Research Center, University of Miyazaki, Japan |
| A subpicosecond VUV seed beam at 126 nm has been produced by the nonlinear frequency up-conversion of a near infrared femtosecond Ti:sapphire laser at 882 nm in rare gases. We obtained the maximum output of the 7th harmonic at 126 nm in Xe at the pressure of 2.5 Torr among three rare gases, Ar, Kr, and Xe. The 126 nm seed beam will be amplified by an optical-field-induced ionization amplifier, which could result in high-power sub-picosecond VUV pulses at 126 nm |
|
CP 02. Physical
and Chemical Processes in the Working Mixture of I2-Laser of the UV-Range
with Optical Pumping |
| B.S. Alexandrov, V.N.
Baboshin, V.P. Fokanov and A.B. Pavlov Russian Scientific Center “Applied Chemistry”, Russia |
| I2-laser of the UV-range with optical pumping can be used in lidar system for monitoring the atmosphere impurities containing nitrogen or sulfur (SO2, NO2, etc.). The spectrum of excitation of luminescence of electronic transitions D'→A' of molecular iodine in a gas phase is presented. Effective working mixtures of I2-laser with optical pumping on a basis of perfluoroalkanes have been found. |
|
CP 03. Fluorescence
and Transient Absorption Spectra of Excimer Laser Mixtures |
| A.O. Levchenko, N.N.
Ustinovskii and V.D. Zvorykin P.N. Lebedev Physical Institute, Moscow, Russia |
| Fluorescence and transient absorption spectra of various rare gas mixtures with additions of fluorine-containing gases and nitrogen under e-beam pumping were investigated with the original time-gated probing technique. The obtained results allow us to specify KrF laser kinetics. Amplification of radiation at broadband trimer Kr2F(42Γ->1,22Γ) transition was demonstrated. |
|
CP 04. Advances
in Industrial High-Power Excimer Lasers Technology |
| I. Bragin, T. Misyuryaev,
A. Targsdorf, I. Klaft, L. Herbst, W. Zschocke and K. Schmidt Coherent GmbH, Germany |
| The paper presents a review of the most recent achievements as well as a discussion on the main directions in the development of the industrial high power excimer lasers. The results of the development of a XeCl lasers with the output energy above 900 mJ and the pulse repetition frequency up to 600 Hz will be described. The system performance such as energy stability as well as the life time issues necessary for the extended maintenance cycles and finally low cost of operation in industrial applications will be discussed. |
| D. SHORT PULSE AMPLIFICATION |
|
DI 01. High Average
Power Ultrafast Fiber Amplifiers |
| E. Mottay Amplitude Systemes, France |
| We report on high average power, high energy ultrafast fiber amplifiers. Different configurations, using chirped pulse amplification, and advanced control of non linear amplification are used to produced pulses as short as 60 fs, pulse duration up to 100 W, and high pulse energy. |
|
DI 02. Extreme
Light Infrastructure |
| G. Mourou Laboratoire d'Optique Appliquée, ENSTA - Ecole Polytechnique, France |
| We will describe the European Light Infrastructure, called ELI for Extreme Light Infrastructure, dedicated to the fundamental study of laser-matter interaction in a new and unsurpassed regime of laser intensity: the ultra-relativistic regime (IL>1023 W/cm2). In this regime the laser field is strong enough to accelerate the proton to relativistic velocity leading to superior particle beams. These investigations will rely on an exawatt-class laser ~100-1000 times more powerful than either the Laser Mégajoule in France or the National Ignition Facility (NIF) in the US. In contrast to these projects, ELI will attain its extreme power from the shortness of its pulses (femtosecond and attosecond). The infrastructure will serve to investigate a new generation of compact accelerators delivering energetic particle and radiation beams of femtosecond (10-15 s) to attosecond (10-18 s) duration. Relativistic compression offers the potential of intensities exceeding IL>1025 W/cm2, which will challenge the vacuum critical field as well as provide a new avenue to ultrafast attosecond to zeptosecond (10-21 s) studies of laser-matter interaction. ELI will afford wide benefits to society ranging from improvement of oncology treatment, medical imaging, fast electronics and our understanding of aging nuclear reactor materials to development of new methods of nuclear waste processing. |
|
DI 03. Towards
High Power, High Repetition Rate, Ultrashort Laser Pulses |
| G. Figueira Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Portugal |
| Diode-pumped solid-state laser media offer an efficient, high repetition rate alternative for pumping current and future ultrahigh-intensity laser systems. The conjugation of this approach with ultrabroadband parametric amplification techniques such as OPCPA is a promising candidate for generating high-energy, few-cycle optical pulses, bringing the focused laser intensities into the ultra-relativistic domain. |
|
DO 01. Petawatt
and Multy-Petawatt Lasers: Status Quo and Perspectives |
| E.A. Khazanov Institute of Applied Physics of Russian Academy of Science, Russia |
| We discussed physical aspects and perspectives of three types of petawatt lasers (neodymium glass, Ti:sapphire, and optical parametric amplifiers) as well as new ideas how to overcome a petawatt barrier. |
|
DP 01. Spatio-Temporal
Distortions in Chirped Pulse Amplification Grating Compressors |
| M. Fernandes and G.
Figueira Grupo de Lasers e Plasmas, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Portugal |
| The spatio-temporal distortions resulting from the propagation of beams with common wavefront distortions through grating compressors are analyzed using the formalism of Kostenbauder matrices. Given that grating compressors introduce aberrations themselves, the implications of using wavefront correction devices at specific points of the laser chain are considered in terms of an overall optimization of the focused beam intensity. |
|
DP 02. Focal
Spot Improvement of a Chirped Pulse Amplification Laser by Using a Single Actuator
Mechanical Deformable Mirror |
| G. Figueira, N. Lopes,
H. Pires, M. Fernandes, J. Wemans, L. Cardoso, T. Imran and N. Cornet Grupo de Lasers e Plasmas, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Portugal |
| An innovative mechanical deformable mirror capable of correcting simultaneously astigmatism and defocus is used to optimize the focal spot of a 10 TW chirped pulse amplification laser. The focused intensity has increased by more than an order of magnitude, with a focal spot of 1.14 times the diffraction limit. This deformable mirror can be used advantageously to correct static aberration in similar laser systems. |
| E. RESONATORS AND ACTIVE OPTICS |
|
EO 01. A 1 kW
Azimuthally Polarized CO2 Laser |
| M. Endo Department of Physics, Tokai University, Japan |
| A 1 kW azimuthally polarized laser beam is generated with a commercial CO2 laser by employing a novel triple-axicon retroreflector unit. The technique is capable of generating radially polarized beam, too. Scalability and reliability of the proposed method is proven by the series of material processing experiments. |
|
EO 02. High Power
Infrared Super-Gaussian Beams: Generation, Propagation and Applications
|
| N.C. du Preez, A. Forbes,
L.R. Botha and M.M. Michaelis Scientific Development and Integration, South Africa |
| We present a CO2 laser resonator that makes use of an intracavity diffractive mirror to generate a super-Gaussian beam as the output mode. We demonstrate the concept on a high average power TEA CO2 laser, and consider the propagation of the output field from source to target, as well as various applications including paint stripping and laser propulsion. |
|
EO 03. Numerical
Characterization of Toric Unstable Confocal Optical Resonators |
| M. Shirmahi and M.H. Mahdieh Department of Physics, Iran University of Science and Technology, Iran |
| In this paper the performance of positive branch toric unstable resonators have been investigated. Based on Fresnel-Kirchhoff integral, the wave-front phase and intensity characteristics of resonator across the output mirror were calculated. Modal behaviour of resonator was also studied for varieties of Fresnel number and magnification as two geometrical characterizing parameters. The power extraction of toric unstable resonator has been also evaluated by calculating Finesse factor. |
|
EP 01. Optical
Components of Adaptive Systems for Improving Laser Beam Quality |
| Y.I. Malakhov, V.V.
Atuchin, A.V. Kudryashov and F.A. Starikov International Science and Technology Center, Russia |
| The overview is given of optical equipment developed within the ISTC activity for adaptive systems of new generation allowing for correction of high-power laser beams carrying optical vortices onto the phase surface. They are the kinoform elements of fused quartz, wavefront sensors, bimorph adaptive mirrors. |
|
EP 02. Correction
of Vortex Laser Beams in a Closed-Loop Adaptive System with Bimorph Mirror
|
| F.A. Starikov, V.P.
Aksenov, V.V. Atuchin, I.V. Izmailov, F.Yu. Kanev, G.G. Kochemasov, S. M. Kulikov,
A.N. Manachinsky, N.V. Maslov, A.V. Ogorodnikov, I.S. Soldatenkov and S.A.
Sukharev Russian Federal Nuclear Center – VNIIEF, Russia |
| We demonstrate the sensing of laser beams with vortex phase surface by a Hartmann-Shack sensor with new reconstrucrion technique and correction of phase singularity in the close-loop adaptive system including the bimorph deformable piezoceramics-based mirror. |
| F. NOVEL APPROACHES |
|
FI 01. CW Diode
and Fibre Pumped Mid-IR OPOs for Spectroscopic Purposes |
| K. Boller University of Twente, The Netherlands |
| To be provided. |
|
FO 01. Q-switching
with a Dual Mode Single Crystal Photo-Elastic Modulator |
| F. Bammer and R. Petkovšek Institute for Forming and High Power Laser Technology, Vienna University of Technology, Austria |
| A new method for Q-switching is examined theoretically and experimentally. It is based on switching of polarization with a single crystal photo-elastic modulator that works simultaneously on two different eigenmodes. This device together with a polarizer in the laser cavity opens the optical path with a constant repetition frequency in the 100 kHz-range for short time gaps in the range of µs. The device is simple, small, cheap and easy to drive. |
|
FO 02. Broadband
Optical Parametric Chirped Pulse Amplification with Group Velocity Matching by
Angular Dispersion of Chirped Pump Pulses |
| L. Cardoso, H. Pires and G. Figueira |
| We study the application of angular dispersion to chirped pump beams in optical parametric chirped pulse amplification as a method to broaden the gain bandwidth, with minimal distortion to the signal beam. This approach is simulated for several nonlinear crystals amplifying a bandwidth capable of supporting few-cycle pulses. |
|
FO 03. Radially
Polarized High-Power Lasers |
| T. Graf, A. Voss, M.A.
Ahmed, M.M. Vogel, A. Austerschulte, J. Schulz and V. Metsch Institut für Strahlwerkzeuge (IFSW), University of Stuttgart, Germany |
| We present an overview of the current activities and different techniques to generate radially polarized beams in CO2 and solid-state lasers. |
|
FO 04. Mode Field
Adapters for application in High Power Fiber Lasers |
| Ana Alves and Rosa
Romero Multiwave Photonics, S.A., Portugal |
| The fundamental mode of a singlemode fiber to a large mode area (LMA) fiber is demonstrated using a mode field adapter (MFA). A fiber taper technique is used to manufacture this MFA which has applications in high power fiber lasers. This device ensures operation in the fundamental mode with excellent beam quality and low insertion losses when adapting two different types of fibers. |
|
FO 05. Prognosis
of the Copper Bromide Laser Generation through Statistical Modeling
|
| I.P. Iliev, S.G. Gocheva-Ilieva
and N.V. Sabotinov Dept. of Applied Mathematics and Modelling, Paisii Hilendarski University of Plovdiv, Bulgaria |
| A new statistical approach to predict the possible increase of the laser generation in copper bromide laser is presented. The results are based on the experimental data treated by the multivariable factor analysis and multiple regression modeling. The increase of the output laser power is investigated with respect to six input working parameters. |
|
FO 06. Finite
Element Optimization for High Precision CO2-Lasers |
| M. Bohrer and D. Schuöcker Lasertec GmbH, Austria |
| The technological development during the past decade showed a strong tendency towards Nd:YAG and diode lasers. Nevertheless CO2 lasers are the first choice where the longer wavelength is better absorbed as e.g. in rubber and photopolymer. Three dimensional direct laser engraving applications are an upcoming application now with a laser power of several hundred watts up to one kilowatt. Single dots with a tip diameter of less than 20 microns can be precisely shaped if the complete resonator design is newly designed with finite element methods and modern material to allow a precision never seen before with CO2 laser. Actual resonator developments and applications are discussed as well as a forecast for the next decade. |
|
FP 01. High Efficiency
Diode-Pumped Parametric Amplification of Optically Synchronized Pulses
|
| H. Pires, L. Cardoso,
J. Wemans, C. João and G. Figueira Grupo de Lasers e Plasmas, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Portugal |
| We evaluate the performance of an optically synchronized, high efficiency parametric amplifier, based on diode laser pumping, and operating in the picosecond regime. The pump source is derived from an ytterbium-based amplifier, and a supercontinuum seed pulse is generated through a photonic crystal fiber. Both pulses are derived from a common 100-fs infrared oscillator. |
| G. LASER MATTER INTERACTIONS |
|
GI 01. Laser
Processing of Materials at High Vibrational Excitation Density |
| S.L. Johnson, N.L. Dygert, K.E. Schriver, H.K. Park and
R.F. Haglund, Jr. Department of Physics and Astronomy, Vanderbilt University, USA |
| A new paradigm for laser processing of materials capitalizes on high-intensity vibrational, rather than electronic, excitation. Resonant mid-infrared laser ablation, for example, is an efficient thin-film deposition method for small organic molecules, polymers and functionalized nanoparticles that are difficult to volatilize non-destructively using visible or ultraviolet lasers. We describe applications such as the fabrication of organic light-emitting devices, and adumbrate our current understanding of the underlying physical mechanisms. |
|
GI 02. Attosecond
Spectroscopy Comes of Age |
| R. Kienberger Max-Planck-Institute of Quantum Optics, Germany |
| New insight into ever smaller structures of matter and their ever faster dynamics hold promise for pushing the frontiers of many fields in science and technology. Pump/probe experiments turned out to be the most direct approach to time-domain investigations of fast-evolving microscopic processes. The emergence of intense waveform-controlled few-cycle near-infrared (NIR) laser pulses and isolated sub-femtosecond XUV pulses has opened the door for direct time-domain access to electron motion on the atomic scale. |
|
GO 01. Quantum
Dynamics of Atomic and Nuclear Ensembles in a Strong Laser Field: Optical Bi-stability
Effect and Nuclear Quantum Optics |
| A.V. Glushkov and O.Yu.
Khetselius Institute of Spectroscopy of Russian Academy of Sciences, Russia |
| It is carried out modelling quantum dynamics of atomic and nuclear ensembles in an intense laser field and new effects of the optical bi-stability, nuclear polarization and dynamical Stark effect for nuclei are described as effects of the super strong laser-matter interaction. |
|
GO 02. Laser-Induced
Bubble Dynamics near Elastic/Soft Material |
| K. Maeno, M. Ota, Shinsuke Udagawa, S.
Nakajima and Y. Yamamoto Graduate School of Engineering, Chiba University, Japan |
| This paper deals with an experimental investigation on the dynamics of a laser–induced single bubble and the pressure waves near the rigid material and near the elastic/soft material in the distilled water at room temperature and pressure. The single bubble is generated by focusing a pulsed Nd:YAG laser. We clarify that the laser-induced bubble moves toward the aluminum wall (rigid material), on the other hand the bubble moves away from the foam rubber wall (elastic/soft material) during rebounding process by visualization. |
|
GO 03. Colouring
Fabrics with Excimer Laser to Simulate Encoded Images: the Case of the Shroud of Turin |
| P. Di Lazzaro, G. Baldacchini,
G. Fanti, D. Murra and A. Santoni ENEA, Frascati, Italy |
| We present excimer laser irradiation results of a raw linen fabric and of a linen cloth. The permanent coloration of both linens is a threshold effect of the laser beam intensity and it can be achieved only in a narrow range of irradiation parameters. We also obtained the first direct evidence of latent images impressed on linen that appear in a relatively long period (one year) after laser irradiation that at the moment did not generate a clear image. The results are compared to the characteristics of the Turin Shroud. |
|
GO 04. KrF Excimer
Laser Treatment of Human Dentin |
| S. Eugénio,
R. Vilar, V. Oliveira and M. Sivakumar Dept. of Materials Engineering, Instituto Superior Técnico, Technical University of Lisbon, Portugal |
| The present paper summarizes the results of a study of the morphological, structural and compositional changes caused on dentin by processing with KrF excimer laser (λ = 248 nm). Different surface textures are achieved depending depending on the structure of the samples and on the processing parameters. Independently of the radiation fluence used, a significant reduction of the organic material content is observed in a surface layer a few nanometers thick, but no significant changes in the mineral phase occur. |
|
GO 05. Pulsed
Laser Deposition of Ferromagnetic Alloys for Spintronics - An Overview
|
| C.E.A. Grigorescu,
E. Valerio, O. Monnereau, L. Tortet, D. Savastru and M. Autric National Institute R&D Optoelectronics INOE 2000, Romania |
| This work is an overview of the preparation by pulsed laser deposition (PLD) and characterisation of ferromagnetic metal compounds as novel materials in the Heusler system. |
|
GO 06. The Absorptivity
of Low-Carbon Steel under Nd:YAG CW Laser Loading |
| G.B. Wang, C.Y. Wang,
Y.Q. Zhang, X. Xiong and X.S. Tang Institute of Fluid Physics, Chinese Academic of Engineering Physics, China |
| The temperature-dependent reflectivity of 30CrMnSiA, which is a high strength, quenching and tempering steel, irradiated-by Nd:YAG continuous wave laser with a wavelength of 1064 nm has been obtained through experiments. Two integrating sphere method which can avoid the fluctuation of laser output energy has been used to measure the reflectance of the surface, and the back surface temperature has been recorded by NiCr-NiAl thermocouples. Surface oxide films composition and thickness were studied by XPS. A one-dimensional model taking into account the temperature-dependent material thermal physical properties and the oxide growth which can affect the absorption characteristics of the surface was built to explain the reflectivity curve. The computational results were in reasonable agreement with the experimental results. |
|
GP 01. Super
Intense Laser Field on Surface of the Porous Materials with Forming Atto-second
Laser Plasma and Possible Nuclear Fission |
| A.V. Glushkov, O.Yu.
Khetseliusb and A.V. Loboda Institute of Spectroscopy of Russian Academy of Sciences, Russia |
| It is carried out studying super intense laser field on surface of the porous materials with forming atto-second laser plasma and possible nuclear fission. It is carried out modelling the femto-second laser plasma, which is forming in the porous materials under action of the intense laser field. Special attention is devoted to the modelling the system: the nano-structured porous material with clusters, on surface of which there is a great number of bonds with D-and OD group’s. |
|
GP 02. Modification
of Polymer Surfaces by Laser Treatment |
| A. Lorusso, V. Nassisi,
F. Paladini, A. Rainò, M. V. Siciliano and L. Velardi Dept. of Physics, University of Salento, Italy |
| It is well known that surface treatment by laser beam application is a good method to modify surfaces without causing thermal damage. In this work, PMMA and UHWMPE polymers were irradiated by two different lasers, an UV and an IR source. We studied the modification of their surfaces measuring the wettability of the treated and no-treated zones. |
|
GP 03. Laser
Coloring Method by Multicolor Toner Using Waveguide CO2 Laser
|
| M. Tobe, Y. Ishii and
Y. Kubota Department of Information Systems Science, Faculty of Engineering, SOKA University, Japan |
| It has been investigated that laser toner coloring (LTC) method which is coloring technique using CMYK (Cyan, Magenta, Yellow, Black) toner for color laser printer. This method is coloring technique fixed heating toner on material surface using waveguide CO2 laser. It is possible to dye nonlimiting colored material and full color expression. In this paper, we have discussed experimental conditions in this method. |
|
GP 04. Coloring
on Transparent Resin Materials Using Waveguide CO2 Laser
|
| M. Kaneko, M. Tobe,
Y. Ishii and Y. Kubota Department of Information Systems Science, Faculty of Engineering, SOKA University, Japan |
| It is difficult to color transparent resin materials by a traditional method, moreover, it is non-effective because of the necessity for much coloration time and much coloration dye. Therefore we improved laser plastic coloring (LPC) method which we had already devised in our laboratory and considered new coloring system which was more effective than a thing of transparent resin materials. In this paper, we describe the construction of coloring system using waveguide CO2 laser and the fundamental coloration experiment using this system. |
|
GP 05. EUV and
Debris Characteristics of a Laser-Plasma Tin-Dioxide Colloidal Target
|
| M. Kaku, S. Touge,
M. Katto and S. Kubodera Department of Electrical and Electronic Engineering and Photon Science Center, University of Miyazaki, Japan |
| We have been developing a laser-produced plasma extreme ultraviolet (EUV) emission source at 13.5 nm by use of a colloidal jet or droplet target containing tin-dioxide nano-particles. The use of a low-concentration colloid of nano-particles and the use of double laser pulse irradiation scheme with an optimized delay time have minimized ionic debris emission from a plasma and have maximized the EUV emission conversion efficiency simultaneously. Characteristics of debris emissions other than ions together with its reduction methods have been verified. |
|
GP 06. Bioactive
Ceramic Glasses “In Situ” Synthetised by Laser Melting
|
| M. Taca, E. Vasile,
L. Boroica, M. Udrea and R. Medianu Metav-Cercetare Dezvoltare S.A., Romania |
| The synthesis of bioactive glass from raw materials even during the laser deposition process, provide formation of a biocompatible layer on the metallic prosthesis. During the laser irradiation melting and ultrarapid solidification of ceramic materials occur and glasses controled by the process parameters (especialy laser power and solidification rate) will be obtained. The aim of the present paper is to study the influence of the processing parameters on the laser sinthetised glasses chemical composition, structure and bioactive behaviour. |
|
GP 10. Behaviors
of Keyhole in the Nd:YAG Laser Welding of 5A90 Aluminum Alloy |
| D. Aiqin and C. Li National Key Laboratory For High Energy Density Beam Processing Technology, Aeronautical Manufacturing Technology Research Institute, China |
| The behavior of keyhole during Nd:YAG laser welding of 5A90 aluminum alloy has been experimentally studied by using a high-speed video camera that allowed us to analyze the main behaviors of keyhole. Depending on welding speed and laser power, different geometry and frequency of keyhole can be observed. The results show that keyhole is period closing and opening at certain depth of keyhole, and the top and bottom shapes of keyhole have great changes during a cycle. It is also found that closing time of bottom keyhole is affected by welding parameters. Based on the experimental result, some relations between behavior of keyhole and welding parameters were obtained. |
|
GP 11. Research
on the Plume Features for YAG Laser-Plasma Arc Hybrid Welding of Stainless Steel
|
| C. Li and D. Aiqin National Key Laboratory For High Energy Density Beam Processing Technology, Aeronautical Manufacturing Technology Research Institute, China |
| The laser-plasma hybrid welding of stainless steel was conducted to investigate the hybrid arc, light induced metal vapor and keyhole behavior by means of high speed camera in this paper. |
|
GP 12. Comparative
Time Resolved Shadowgraphic Imaging Studies of Nanosecond and Picosecond Laser
Transfer of Organic Materials |
| L. Rapp, C. Cibert,
A.P. Alloncle, P. Delaporte, C. Videlot-Ackermann, F. Fages and S. Nenon Laboratoire LP3 (Lasers, Plasma et Procédés Photoniques), Université de la Méditerranée, France |
| A comparative study of the dynamic of the ejection using short (35 ns) and ultrashort (50 ps) pulses by Laser Induced Forward Transfer technique has been performed on organic materials for applications in plastic micro-electronics. The ejection has been investigated by shadowgraphic imaging from the laser irradiation pulse to 1.5 µs. |
|
GP 13. Effect
of H2 Addition on the Surface Morphology and Microstructure of Co-TiO2
Films Grown by Pulsed Laser Deposition |
| N. Popovici and O.
Conde University of Lisbon, Faculty of Sciences, Dept. of Physics and ICEMS, Portugal |
| We report on the Pulsed Laser Deposition of Co-doped TiO2 thin films carried out in a background atmosphere containing hydrogen, and on the dependence of surface morphology and microstructure on H2 dilution. |
|
GP 14. Laser
Speckle Imaging Condition for Personal Identification Using High Peak Power Laser-Induced
Crack |
| T. Shutou, D. Tokita,
Y. Kubota and K. Watanabe Department of Information Systems Science, Faculty of Engineering, Soka University, Japan |
| A new personal identification method that combined laser-induced crack and speckle pattern has been developed in our laboratory. In this method, the identification object has been discriminated by matching speckle patterns from a crack which is produced by a high peak power laser with a registered template image. In this report, experimental results as various speckle imaging conditions were shown by changing a probing laser axis against 3-D crack. |
|
GP 15. Non-Linear
Ionization of Atomic and Molecular Gases by Intense UV Femtosecond Laser Pulses
|
| A.A. Ionin, S.I. Kudryashov,
Yu.N. Ponomarev, L.V. Seleznev, D.V. Sinitsyn, B.A. Tikhomirov and V.D. Zvorykin Lebedev Physical Institute of Russian Academy of Sciences, Russia |
| Non-linear ionization of atomic and molecular gases by intense UV femtosecond laser pulses was studied by complementary electrometric and optoacoustic techniques. Corresponding laser-field induced transient changes of ionization mechanisms are discussed. |
|
GP 16. High Power
Repetition Rate Q-switched CO2 Laser and its Application to Study the
Optical Breakdown in a Supersonic Air Stream |
| A.N. Malov, A.M. Orishich
and V.B. Shulatyev Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Russia |
| A high power repetition rate CO2 laser with mechanical Q-factor modulation has been manufactured. Its generation characteristics have been studied. The structure of shock waves appearing at the interaction between a supersonic air jet and plasmoid formed by the optical breakdown, has been investigated. |
|
GP 17. Thermal
Effects Induced on Dental Hard Tissues by Nanosecond Nd:YAG Laser
|
| A. Antunes, E.B. Amôres,
W. de Rossi and D.M. Zezell Universidade de São Paulo, Brazil |
| The characterization of dental hard tissues subjected to laser irradiation has been performed using distinct experimental techniques, among them: scanning electron microscopy, microhardness testing and infrared absorption spectroscopy. The study of thermal damage on hard tissue surface is indicated to avoid pulpal injury which is normally the main difficulty to applications in Dentistry. In this investigation thermal effects of Nd:YAG laser irradiation on enamel and dentine were evaluated. |
|
GP 18. Ternary Ferromagnetic Nitrides Obtained by Pulsed Laser Deposition
|
| I.D. Feraru, C. Constantinescu,
D. Savastru, O. Monnereau, L. Tortet, R. Notonier, A. Tonetto, A. Galatanu, C.I.
Vasiliu, M.Dinescu and C.E.A. Grigorescu National Institute R&D Optoelectronics, Romania |
| We present an experimental study in the attempt to grow ternary ferromagnetic insertion nitrides (CoFe-N) by pulsed laser deposition. |
| H. MICRO AND NANO FABRICATION |
|
HI 01. Laser-Based
3D Micro- and Nanofabrication |
| B. Chichkov Laser Zentrum Hannover, Germany |
| Recent advances in the development of high resolution, direct laser writing technologies for the fabrication of three-dimensional (3D) micro- and nanostructures will be discussed. By tightly focusing femtosecond laser pulses into the volume of a photosensitive material any 3D micro-structure can be fabricated by the recently developed two-photon polymerization (2PP) technique. In this presentation, microstructuring of organic-inorganic hybrid materials (also nonlinear materials) will be reported. Different examples of 3D microstructures, such as microoptic and plasmonic components, and 3D photonic crystals, including investigations of their optical properties will be presented. Biomedical applications of 2PP technique will be highlighted. |
|
HI 02. Laser
Micro/Nanoprocessing for Functional Electronics |
| S. Hwan Ko, H. Pan
and C.P. Grigoropoulos University of California, USA |
| A new paradigm will be presented for the low temperature fabrication of passive and active electrical components on a flexible polymer substrate by laser processing of inkjet printed metal nanoparticles. Selective laser sintering and pulsed laser ablation via the differential ablation threshold (SPLA-DAT) scheme will be discussed. Fundamental mechanisms of the nanoparticle sintering process have been investigated by both Molecular Dynamics (MD) simulations as well as in-situ probing. |
|
HO 01. Laser
Percussion Micro-Drilling of Aluminium Alloys by 532 nm Green Light
|
| G. Daurelio, E.S. Andriani,
M. D’Alonzo, D. Marano and I.M. Catalano Physics Department of University and Polytechnic of Bari- Via Amendola, Italy |
| The aim of this work was the possibility to obtain micro-drills on the range from 500 to 25 µm diameters with some aspect ratio high values. At the same time the realization of some “blind drills”, “passing holes” as well as “straight and tilted holes” were proved. |
|
HO 02. Laser-Induced
Nanochemistry, Ablation, and Plasma Spectroscopy in the Near-Field of an Optical
Fiber Tip |
| J. Heitz, S. Yakunin,
T. Stehrer, G. Wysocki and D. Bäuerle Institute of Applied Physics, Johannes Kepler University Linz, Austria |
| We combine laser processing and scanning near-field optical microscope (SNOM) technique for realization of laser-induced chemical reactions on a nanoscale, laser ablation near the fiber tip, and micro-analysis of solid surfaces samples by laser-induced breakdown spectroscopy. |
|
HO 03. Laser
Engraving of Paper and Polymeric Materials for Tactile Detection |
| J.A. Ramos-de-Campos,
J. Gamo, C. Soriano, P. Varela and E. Pérez AIDO, Spain |
| This study is focused on laser structuring processes for producing secure tactile features on polymer and paper-based security documents. The feasibility of using the developed technique allows users and/or machines to discriminate among genuine and counterfeited security documents and/or facilitate the tactile detection by visually impaired people. |
|
HO 04. Laser
Plasma Source of Extreme Ultraviolet (EUV) for Micro and Nano-fabrication
|
| A. Bartnik, K. Dabrowski, H.
Fiedorowicz, R. Jarocki, J. Kostecki, P. Puchalski, R. Rakowski, M. Sawicka,
A. Szczurek and M. Szczurek Institute of Optoelectronics, Military University of Technology, Poland |
| A compact laser plasma source of extreme ultraviolet (EUV) based on a gas puff target irradiated with high-power laser pulses is presented. The source is equipped with various optical systems (grazing incidence ellipsoidal mirrors, “lobster eye” multifoil mirror, and ellipsoidal mirror with Mo/Si coating). Characterization measurements of the source and application for micro and nanoprocessing polymers are demonstrated. |
|
HP 01. Laser
Direct Imaging Method of Creating Electric Connections on High Density PCB’s
|
| R. Barbucha, M. Kocika
and J. Mizeraczyk The Szewalski Institute of Fluid-Flow Machinery, Poland |
| The interconnection complexity of the PCB (Printed Circuit Boards) is still growing and new technologies are introduced in the production of high density printed circuit boards. Recently the Laser Direct Imaging (LDI) technology is used for imaging electric circuits directly on PCB without the use of a phototool or mask. We presents our laboratory system for Laser Direct Imaging designed for tracks and spaces on PCB with minimum width distance of 50/50 μm. |
|
HP 02. System
for Laser Micromachining of Thin Metal Foils |
| R. Barbucha, M. Kocik
and J. Mizeraczyk The Szewalski Institute of Fluid-Flow Machinery, Poland |
| In this paper a prototype of laser system for micromachining of the materials (ULMM) is presented. This system is used for metal foils cutting, in particular for cutting stencils used in cladding soldering paste in PCB (Printed Circuits Board) production process. In this paper a schema, parameters, capabilities and examples of ULMM applications are presented. |
|
HP 03. Femtosecond
Pulsed Laser Irradiation of Silicon at 1030 nm |
| V. Oliveira, B. Nunes,
R. Colaço and R. Vilar Dep. Engineering Materials, Instituto Superior Técnico, Universidade Técnica de Lisboa, Portugal |
| We report the formation of conical microspikes in silicon wafers processed in air with a 1030 nm Ytterbium doped femtosecond pulsed laser. |
|
HP 04. Two Dimensional
Data Matrix Consisted of Metal Ablation Dots Produced by a Nano-Second 2nd
Harmonic Nd:YAG Laser |
| H. Eshima, D. Tokita,
Y. Kubota, Y. Ishii and K. Watanabe Department of Information Systems Science, Faculty of Engineering, Soka University, Japan |
| Two dimensional data matrix has been proposed which is consisted of ablation dots on metal surface by means of a diode pumped, high peak power Nd:YAG laser. Because of unique structure of ablation dots arranged on the two-dimensional data matrix, the code on the matrix could be unique in its speckle pattern even if the matrix has the same arrangement. |
| I. NOVEL MACRO PROCESSING |
|
II 01. Processing
with kW Fibre Lasers - Advantages and Limits |
| A. Kratky, D. Schuöcker
and G. Liedl Institute for Forming and High Power Laser Technology, Vienna University of Technology, Austria |
| Applications of fibre lasers are discussed and compared to those of classical laser systems. Very high intensities of the laser beam are very often not required for the majority of applications in processing of metals or are sometimes even disadvantageous. Within the following paper, processing limits of a 1.5 kW fibre laser are described and discussed. |
|
II 02. Laser
Based Hybrid Technique for Civil Engineering |
| S. Muto, K. Tei, S.
Yamaguchi, K. Nanri and T. Fujioka Department of Physics, School of Science, Tokai University, Japan |
| The laser based hybrid technique is effective for concrete cutting and rock drilling. Experimental conditions included 1-10 kW laser power, 5-10 mm laser beam diameter, 1-50 mm/s scanning speed, and 0-50 L/min O2 gas flow rate. Results of surface scanning tests and 100 mm deep cut tests indicated that the shortest operation time was about 3.5 hr/m2 for plain concrete and 4.5 hr/m2 for heavy concrete. The specific energy of rocks (granite and sandstone) was as same as heavy concrete. |
|
II 03. Surface
Engineering: Amorphous Alloys and Nanocrystallinity |
| J.T.M. De Hosson, D.T.A.
Matthews and V. Ocelik Dept. of Applied Physics, Materials Innovation Institute, University of Groningen, The Netherlands |
| This work encapsulates the production and properties of metallic amorphous and nanocrystalline alloys. Laser surface engineering has been proven to be a viable production method for developing thick amorphous coatings and their properties are shown to include high hardness, low friction and good wear resistance to both dry-sliding wear and, in the case of nanostructured coatings, abrasive wear. |
|
II 04. Advanced
Systematic Theory of Laser Welding Supported by High Speed Imaging
|
| A.F.H. Kaplan Luleå University of Technology, Sweden |
| Due to highly complex physics and mechanics behind, the causes of laser welding defects like undercuts, lack of fusion or pores and their impact on the fracture mechanics under load are only partially understood. High speed imaging enables to identify and study intermediate process and load conditions, respectively, that might fully determine whether and when certain welding defects occur and cause failure in operation. Accompanied by modelling and simulation, a systematic approach is aimed at for a theoretical description of the essential effects. |
|
IO 01. Experimental
Search of Similarity Criteria for the High-quality Cutting of Mild Steel
|
| A.M. Orishich, A.G.
Malikov and V.B. Shulyatyev Khristianovich’s Institute of Theoretical and Applied Mechanics, SB RAS, Russia |
| For mild steel of 5… 25 mm thick, the area of parameters where the cutting quality is maximum, has been determined experimentally. The conditions of cutting with minimum roughness are presented as a dependence of dimensionless values. It has been shown that the high-quality cutting features the specific volumetric input of laser energy same for any thickness. |
|
IO 02. Microstructure
of Laser Clad Coatings Studied by Orientation Imaging Microscopy |
| V. Ocelík and
J.Th.M. de Hosson Dept. of Applied Physics, Materials Innovation Institute, University of Groningen, The Netherlands |
| Orientation Imaging Microscopy based on electron back scatter diffraction was applied to study the microstructure of individual laser tracks and coatings made from Co-based alloy on steel substrate. The influence of processing parameters as well as geometry of overlapping laser tracks on microstructural features as grain size, texture and grain grow orientation was studied. |
|
IO 03. A Simple Approach for the Estimation of Dilution in Laser Cladding |
| A. Moita de Deus and
Jyoti Mazumder Dept. Materials Engineering, Instituto Superior Técnico, Portugal |
| Laser Cladding (LC) is a coating manufacturing technique, in which a laser beam is used to deposit one or several layers of a certain clad material onto a substrate, in such a way that a sound interfacial bond is formed. When cladding dissimilar materials, usually one aims at optimizing process parameters so that significant dilution of one material into the other does not occur. Otherwise, the clad composition would be significantly altered from a value that is often arbitrated with a certain application in mind; besides, a set of new and often undesired phases could also solidify from the melt. In this paper, a simple temperature-based model is proposed for the estimation of the overall composition change of clad beads, as well as the composition gradient that is expected to occur in the transition layer between the clad and the substrate regions, as a function of processing parameters such as laser scanning speed, laser power and powder feed rate. Such relationships can be useful for obtaining processing maps, as well as a tool in further numerical computations of temperature, microstructure or stress fields, as it allows a simple estimation of local physical properties, which usually vary significantly with composition. |
|
IO 04. Laser
Beam Welding Aerospace Aluminum using Fiber Lasers |
| M.S. Fernandes de Lima,
R. Riva, A. Capella de Oliveira and G.R. Siqueira IEAv - Instituto de Estudos Avançados, Brazil |
| Laser beam welding has been used to join sheets of AA6013 for aerospace applications. The observed results indicate that good welds are obtained around 6 m/min and 1kW conditions without filler wire. Both heat affected and liquation zones are very small in all cases. |
|
IO 05. Modeling
of Phase Transformations and Internal Stresses in Laser Powder Deposition
|
| A. Crespo, A. Deus
and R. Vilar Dept. Materials Engineering and ICEMS, Instituto Superior Técnico, Universidade Técnica de Lisboa, Portugal |
| A finite element model coupling heat transfer calculations, phase transformations kinetics and internal stresses calculations to simulate laser powder deposition of a titanium alloy is presented. The model was applied to the study of the influence of the deposition parameters on the microstructure, hardness and residual stresses in Ti-6Al-4V thin walls produced by this method. |
|
IO 06. Wear Resistant
Al-Si/TiC Coatings Prepared by High Power Laser |
| R. Anandkumar, A. Almeida
and R. Vilar Instituto Superior Tecnico, Dept. Materials Engineering, Technical University of Lisbon, Portugal |
| High wear resistance composite coatings were prepared by laser cladding on Al-7 wt.% Si substrates, using powder mixtures of Al-12 wt.% Si + 40 wt.% TiC and Al-40 wt.% Si + 40 wt.% TiC. The microstructure of the coatings was studied in detail by optical microscopy, scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction. Its influence on the coatings hardness and wear behaviour was evaluated. |
|
IO 07. Laser
Cleaning of Calcareous Stones Influence of Laser Irradiation in Colour Changes
of Different Layers |
| S.S. Amaral, M. Pires,
M.D. Carvalho and F.M. Costa Dept. Chemistry and Biochemistry, Fac. Ciências da Universidade de Lisboa, Portugal |
| Experimental laser cleaning of black crusted calcareous stones, carried on to study the laser yellowing of petreous surfaces, showed different colour alterations on the exposed surface, after laser irradiation, depending not only on the incident fluence but also with the crust or stone irradiated layer. |
|
IO 08. Laser
Metal Deposition with Wire: Parameters Optimization and Temperature Monitoring
|
| A. Medrano, J. Folkes
, J. Segal and I. Pashby Innovative Manufacturing Processes Group, School of Mechanical, Materials and Manufacturing Engineering, University of Nottingham, UK |
| This paper addresses the development of a direct metal deposition process which consists of a 2 KW Fibre Laser, a CNC table, a wire feeder and a temperature monitoring system. It utilizes two IR pyrometers to measure both the melt-pool and workpiece (upper layer) temperatures. Experiments have been performed to find the optimum metal deposition parameters with stainless steel 308, and good quality metal deposition has been achieved. The results of the parameters optimization and temperature monitoring are presented and analyzed. |
|
IO 09. Analysis
of Residual Stress and Corrosion Resistance of Laser Shock-Processed 6012 and
6082 Aluminium Alloys |
| U. Trdan, J. Grum and
J.L. Ocaña University of Ljubljana, Faculty of Mechanical Engineering , Slovenia |
| The paper discusses laser shock processing of aluminium alloys Al 6012 and Al 6082 at different overlapping densities. Roughness, microhardness and residual stress profiles and corrosion resistance were analyzed. Results confirmed greater resistance of material to fatigue. |
|
IO 10. Laser
Cladding of Rene N4 onto CMSX-4 Single Crystal Substrates |
| E.C. Santos, P.l Carroll
and R. Vilar Instituto Superior Técnico and ICEMS, Technical University of Lisbon, Portugal |
| Rene N4 powder coatings were produced by laser powder deposition onto CMSX-4 single crystal substrates. The crystallographic and metallographic structures of the substrate and laser deposited material were investigated by Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Electron Backscattered Diffraction (EBSD). The microstructure of the deposits was also analyzed after precipitation heat treatment at different temperature/time cycles. |
|
IO 11. Laser
Powder Deposition of W-TiC Cermelts |
| L. Costa, W. Hofmeister,
D. Rajput and K. Lansford University of Tennessee Space Institute, Center for Laser Applications, USA |
| Refractory metal (W,Ti) – refractory carbide (Ti,W)C cermelts formed by eutectic solidification from the melt are being formed using various laser powder deposition techniques. The typical processing conditions and a representative set of results of this laser materials processing development effort are summarized in this paper. |
|
IO 12. The Use
of Pulsed Laser to Produce Amorphous Surfaces in Ti-Based Alloys |
| B.T. Ramasco, C.S. Kiminami, W.J. Botta, A. Almeida, R.
Vilar and C. Bolfarini Dep. Materials Engineering, Brazil |
| The alloy Ti34Ni8Cu36Zr22 was proposed as a glass former and was obtained in an Arc Melter equipment. Laser remelting of the crystalline ingot produced an amorphous phase, which was confirmed by XRD analysis and DSC traces. This result show that the Laser Technique could be a powerful tool to produce amorphous structure on the surface of Ti-based alloys, contributing to increase wear and corrosion resistance of these alloys. |
|
IP 01. Manufacture
of Metal Foam Layers by Laser Metal Deposition |
| B. Carcel, A.C. Carcel,
I. Perez, E. Fernandez, A. Barreda, J. Sampedro and J.A. Ramosa AIDO, Spain |
| This study explores the potential ability of laser metal deposition (LMD) as metal foaming process, considering that its intrinsic high heating/cooling rates can avoid some of the common problems of gas leakage, inhomogeneity and anisotropy that arise when manufacturing metallic foams by conventional powder metallurgy (PM) methods. Aluminum and titanium alloys porous coatings have been created by this PM-LMD metal foaming method. |
|
IP 02. A Thermo-Kinetic
Model for Laser Powder Deposition of Tool Steels |
| L. Costa and R. Vilar University of Tennessee Space Institute, Center for Laser Applications, USA |
| A thermo-kinetic model of the microstructural transformations and hardness variations that occur during laser powder deposition of AISI 420 tool steel is presented. Results obtained from calculations performed for thin wall builds are compared with available experimental data. Processing conditions that promote heat accumulation in the part during the build-up process are shown to have a substantial effect on the final microstructure and hardness distributions. |
|
IP 04. Investigation
of the Process Efficiency in CO2 Laser Welding of Low Alloyed Steels |
| P. Petrov and T. Apostolova Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Bulgaria |
| This paper reports result from experimental and theoretical study of the laser transfer, melting and joining efficiency during CO2 laser beam welding of low alloyed steels. |
|
IP 05. Microscopic
Modeling of Short Pulse Laser Melting of Materials |
| T. Apostolova and P.
Petrov Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Bulgaria |
| Combined kinetic and two temperature diffusion modeling are used to describe the processes of thermal and non-thermal short pulse laser melting of dielectrics and semiconductors. |
|
IP 06. Removal
of Graffiti Paintings from Mansion “de Mattis”, Sited in Corato (Bari)
- Italy: Laser De-Veiling or Complete Cleaning? |
| G. Daurelio, S.E. Andriani,
A. Albanese, D. Marano, I.M. Catalano and G. Teseo InterDepartement Center “ Search Laboratory for the Cultural Heritage Diagnostic ”, Italy |
| Laser cleaning techniques offered two cleaning possibilities: de-veiling and complete cleaning of the surface. De-Veiling showed a “apparent” complete cleaning surface at human eye but a shadow (residues) of the spray paint appeared if the de-veiled surface is illuminated by an intense flash light , produced by a digital camera with a very high colour temperature. This new laser cleaning technique could represents a possible solution according to the restoring theory that it says a “minimum intervention” for the artwork conservation that needs a particular careful due to the possible superficial de-cohesion. On the other hand if a complete cleaning has preferred, it can be obtained simply increasing the laser fluence (J/cm2) and, thanks to the “hardness” of the stone, with the respectful of the superficial morphology and hue. |
|
IP 07. A New
Monumental Laser Cleaning Technique |
| G. Daurelio Physics Department of University and Polytechnic of Bari- Via Amendola, Italy |
| Four different laser cleaning techniques have been reported and tested before on stone samples and after on diverse monuments in situ. After the usual Degradation Mapping phase the different types of writings, graffiti, black incrustations, paintings, text-liners and paint markers were identified on the different parts of the surfaces. So, according to the results, obtained on the prepared samples, each diverse technique was applied for the different “material” to remove from the stone surfaces. |
|
IP 08. Neural
Networks Optimization of Laser Welding Process |
| F. Caiazzo, V. Sergi
and F. M. C. Minutolo Dip. Ingegneria Meccanica, Università di Salerno, Italy |
| The shape parameters, i.e. melting depth, aspect ratio, welding efficiency, melting width at the sheet interface, melting area, etc., of laser weld bead of various metal alloys worked by means of a laser, varying power density, welding speed and typology of covering gases, were measured in order to evaluate the influence of previous parameters at the same time with the material thermal, physical and chemical characteristics on the quality index of welding. In particular, the study has regarded different lap joints obtained on austenic stainless steel (AISI 304) sheets of different thickness. |
|
IP 09. Simulation
of Geometry and Heat Transfer in a Thin-Walled Structure Produced by Direct Laser
Powder Deposition |
| K. Kheloufi and E.H.
Amara Laser materials processing group, Advanced Technologies Development Centre (CDTA), Algeria |
| In this paper, a three dimensional model for direct laser powder deposition process is developed to simulate the thermal field and geometry in building a single-bead wall (thin-walled structure) using a layer by layer technique. The commercial code Fluent 6.1 cfd, to which several modules were appended (User Defined Functions UDF) was used to accomplish the simulation. The model calculates transient temperature profile, thickness of the generated wall and dimensions of the fusion zone. |
|
IP 10. Thermal
Treatment Effects on Laser Surface Remelting Duplex Stainless Steels
|
| A.M. do Nascimento, M.A. Pinto, S.S.M. Tavares and M.C.F.
Ierardi Department of Materials Engineering, University of Campinas, UNICAMP, Brazil |
| The duplex stainless steels were heat treated after the laser surface remelting and the microstructural changes and corrosion resistance were observed. The results were compared with the starting conditions and could be concluded that the corrosion resistance was restored. |
| J. PROPAGATION, SPACE AND SENSING |
|
JI 01. Lasers
in Space: an Overview of Developments and Missions Opportunities at the European
Space Agency |
| E. Armandillo European Space Agency, Netherlands |
| Solid-state lasers, based on Nd:YAG technology, are today finding many important applications in Space for Remote sensing of the Earth system, in Astronomy, Astrophysics and Planetology, Navigation and Communication, etc. High-power lasers are primarily used in optical radar, namely in LIDAR (Light Detection and Ranging) instruments devoted to the remote sensing of the Earth atmosphere, as required for advanced Meteorology and Climatology. Three lidar types are presently under development at the European Space Agency, a Doppler wind lidar for the ADM mission (Atmosphere Dynamics Mission), a Backscattering lidar for the EarthCare mission (Earth Clouds, Aerosols and Radiation missions), and Differential Absorption lidar for remote sensing of Greenhouse gases. The DWL instrument, Aladin (Atmospheric Lidar Doppler Instrument) utilises a tripled-Nd:YAG laser, diode-pumped with direct detection, with a pulse energy of 130 mJ at a repetition rate of 100 Hz. The backscattering lidar, ATLID is a diode-pumped doubled and tripled Nd:YAG laser with diode pumping emitting pulses of 25-30 mJ and 70-100 Hz. The paper will present the laser development and qualification issues and challenges which need to be solved to fly a high-power laser in space. |
|
JI 02. Propagation
of High Power Partially Coherent Laser Beams in a Turbulent Atmosphere: Modeling
and Experiments |
| V.A. Banakh Institute of Atmospheric Optics of the Russian Academy of Sciences, Russia |
| In this paper we discuss some results of experimental studies of the laser beam thermal blooming. The influence both an atmospheric path and zone of stagnation between the laser source and the optical system on the beam defocusing are analyzed. Computer code for simulation of thermal blooming of a laser beam in a turbulent atmosphere is presented as well. |
|
JO 01. Diode
Laser Interrogated Single-Mode Fiber Optics with a Hetero-Core Structure for a
Wearable Glove Sensing Application |
| M. Nishiyama, H. Sasaki,
Y. Kubota and K. Watanabe Department of Information Systems Science, Faculty of Engineering, Soka University, Japan |
| We have developed hetero-core fiber techniques interrogated with a semiconductor diode laser based on single-mode transmission for wearable glove sensing application. The hetero-core fiber sensor has been found to be highly sensitive, reproducible to macro-bending. The wearable sensing glove with the hetero-core sensors has be successfully detected real-time hand motion for stretching and bending of its finger joints. |
|
JO 03. Visualization
of Velocity Fields in the Atmosphere Based on Scattered Laser Radiation
|
| V.A. Banakh and A.V.
Falits Institute of Atmospheric Optics of the Russian Academy of Sciences, Russia |
| Possibility for visualization of 2D velocity fields in the atmosphere based on laser radiation scattered by the particles moving in a turbulent air flow is discussed. By numerical modeling it is demonstrated that visualization of the flow velocity field is possible based on displacements of large-scale intensity inhomogeneities in the speckle structure arising in the optical image of scattering layer of moving particles. |
|
JO 04. Application
of Particle Image Velocimetry Technique for Study of Reacting Jet Flows
|
| S.V. Alekseenko, V.M. Dulin, Y.S. Kozorezov, D.M. Markovich
and S.I. Shtork Institute of Thermophysics SB RAS, Russia |
| Present work is devoted to experimental study of reacting jet flow in a model open flame burner. The main technique used is a laser based stereo Particle Image Velocimetry (PIV) system which allowed for detailed measurement of three component velocity field. The results presented include data on velocities and turbulent characteristics in isothermal and reacting non-swirled and swirled jets. |
|
JO 05. High
Repetition Rate Pulse-Periodic Lasers for “Impulsar” Applications:
Perspectives for New Technologies |
| V.V. Apollonov Prokhorov General Physics Inst. RAS, Moscow, Russia |
| The objective of the project is to accomplish a circle of experimental, engineering and technological works on creation of a high efficiency laser rocket engine (propulsor). As to estimations of specialists, capability of commercial launch market in 2010 will rise at 50% compared to 2008. Taking into account this factor in developed countries are being conducted investigations on feasibility of creation of rocket propulsor alternative to the existing ones which operate on chemical fuel often far from perfect. To the most prospective rocket propulsors of the new concept should be classified laser rocket engines. Implied is creation of a spaceship which the initial part (acceleration) of its trajectory will be propulsed under action of directed to it from the Earth surface continuous sequence of laser pulses. |
|
JP 01. Propagation
of Shock Wave in a Stepped Structure Model Generated by 2-Dimensional Beam Focusing
of CO2 Pulsed Laser |
| K. Maeno, M. Ota, S. Udagawa,
S. Nakajima and Y. Yamamoto Aerospace Engineering Course, Tokyo Metropolitan College of Industrial Technology, Japan |
| We have performed the micro shock wave visualization with schlieren method by using laser induced plasma, which generated by a focusing pulsed CO2 laser. The propagation and reflection of the shock waves are investigated. |
|
JP 02. Absorption
of a Chain HF/DF-Laser Radiation by Atmospheric Impurities |
| M.A. Azarov, B.S. Alexandrov,
A.P. Burtsev, V.A. Drozdov, V.V. Sudarikov and G.A. Troshchinenko Russian Scientific Center “Applied Chemistry”, Russia |
| Coefficients of absorption of atmospheric impurities for some spectral lines of the chain photoinitiated HF/DF-chemical laser emitting in a wavelength range 2.7 - 3.3 µ and 3.6 – 4.9 µ, respectively, are measured. |
|
JP 03. New Algorithm
for Generating a Very Long Rectangular Turbulent Phase Screen |
| H.-L. Wu, H.-X. Yan,
S.-S. Li and X.-Y. Li Institute of Mechanics, Chinese Academy of Sciences, China |
| Based on the fractal characteristics of turbulence-distorted wavefront, a new algorithm for generating a very long rectangular turbulent phase screen is proposed. The phase structure function of generated phase screens can be very well compared to the theoretical one. In comparison to existing approaches, the present algorithm shows obvious advantages. |
|
JP 04. Experimental
and Theoretical Investigation of Forest Fire Detection by a Portable Eye-Safe
Lidar Operating at 1540 nm |
| A. Lavrov, A.B. Utkin
and R. Vilar INOV - INESC Inovação, Portugal |
| The possibility of early forest fire detection using a portable eye-safe 1540 nm lidar is demonstrated in experiments. An estimation of the detection efficiency, based on the 3D system of Navier-Stokes equations describing the smoke plume evolution in the presence of wind, agrees reasonably well with the experiment. Calculations made for accumulation of 600 lidar returns show that the detection range reaches ~5.5 km. |
|
JP 05. Automatic
Recognition of Smoke-Plume Signatures in Lidar Signal |
| A.B. Utkin, A. Lavrov
and R. Vilar INOV - INESC Inovação, Portugal |
| A simple and robust algorithm of lidar-signal classification based on the fast extraction of sufficiently pronounced peaks and their classification with a perceptron, whose efficiency is enhanced by a fast nonlinear preprocessing that increases the signal dimension, is reported. The method resulted in smoke recognition with an error rate as small as 0.31% (19 misdetections and 4 false alarms at recognition of a test set of 7409 peaks). |
|
JP 06. CARS Measurement
for Non-Equilibrium Radiating Hypervelocity Flow Behind Strong Shock Wave on Nitrogen
Molecules by Controlling High Power Second Harmonics YAG-Dye Laser Pulses
|
| K. Maeno, Y. Endo,
K. Arimura, T.i Osada and M. Ota Department of Mechanical Engineering, Graduate School of Engineering, Chiba University, Japan |
| In this research the strong shock waves with velocity over 5 km/s are generated by a free piston shock tunnel in low-density gas of initial pressure 1333 Pa, and CARS (Coherent Anti-Stokes Raman Spectroscopy) method by high power YAG-Dye laser pulses is applied to the designated position behind strong shock wave, and the signals with high temporal resolution are acquired. N2 vibrational and rotational temperatures are decided by fitting experimental spectroscopic profile data and theoretically calculated spectroscopic profile. |