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André Mysyrowicz - One of the best experts on this subject based on the ideXlab platform.
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Generation of long-lived underdense channels using femtosecond Filamentation in air
Journal of Physics B: Atomic and Molecular Physics, 2015Co-Authors: Guillaume Point, Arnaud Couairon, André Mysyrowicz, Carles Milián, Aurélien HouardAbstract:Using femtosecond laser pulses at 800 and 400 nm, we characterize the formation of underdense channels in air generated by laser Filamentation at the millijoule energy level by means of transverse interferometry. We find that using tight focusing conditions, Filamentation generates a shock wave and that the resulting low-density channel lasts for more than 90 ms. Comparison of these results with hydrodynamic simulations using an Eulerian hydrodynamic code gives an good agreement and allows us to estimate the initial gas peak temperature at ∼ 1000 K. The influence of experimental parameters such as the focusing conditions for the ultrashort laser pulse, its polarization or the wavelength is studied and linked to previous characterizations of Filamentation-generated plasma columns.
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Special issue on Filamentation
Journal of Physics B, 2014Co-Authors: Howard Milchberg, André MysyrowiczAbstract:Journal of Physics B: Atomic, Molecular and Optical Physics is delighted to announce a forthcoming special issue on Filamentation, to appear in the spring of 2015, and invites you to submit a paper. This special issue will attempt to give an overview of the present status of this field in order to create synergies and foster future developments. The issue is open to papers on the following issues: Theoretical advances on Filamentation. Self-focusing and collapse. Filamentation in various media. Pulse self-compression and ultrafast processes in filaments. Molecular alignment and rotation. Filamentation tailoring. Interaction between filaments. Filament weather and pollution control. Filament induced condensation and precipitation. Terahertz science with filaments. Lasing in filaments. Filament induced molecular excitation and reaction. Electric discharge and plasma. Cross-disciplinary applications. Novel concepts related to these topics are particularly welcome. Please submit your article by 1 October 2014 (expected web publication: spring 2015) using our website http://mc04.manuscriptcentral.com/jphysb-iop. Submissions received after this date will be considered for the journal, but may not be included in the special issue. The issue will be edited by Ruxin Li, Howard Milchberg and Andre Mysyrowicz.
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Recent developments in femtosecond Filamentation
Journal of Physics: Conference Series, 2014Co-Authors: Aurélien Houard, Yi Liu, André MysyrowiczAbstract:We review recent developments in the field of femtosecond laser Filamentation.
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Measurement and control of plasma oscillations in femtosecond filaments
Physical Review Letters, 2011Co-Authors: Bing Zhou, Arnaud Couairon, André Mysyrowicz, Bernard Prade, Aurélien Houard, Yi Liu, Patrick Mora, C. Smeenk, Ladan Arissian, Paul CorkumAbstract:The short-lived longitudinal plasma oscillations generated during Filamentation in argon and nitrogen gas are measured with a specially designed current monitor. The magnitude and initial direction of the corresponding currents depend sensitively on laser polarization and nature of the gas. The results are interpreted as resulting from the competition between two forces acting on free electrons born during the Filamentation process: the Lorentz laser force and a Coulomb wake force resulting from a lateral expansion of the plasma.
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Self-focusing and Filamentation of Femtosecond Pulses in Air and Condensed Matter: Simulations and Experiments
Topics in Applied Physics, 2009Co-Authors: Arnaud Couairon, André MysyrowiczAbstract:We review the evolution of the modeling of femtosecond Filamentation in transparent media from the monochromatic self-trapping model to the development of numerical models including all relevant physical effects. We discuss four self-action effects which occur during Filamentation: i) the generation of single cycle pulses by Filamentation in gases, ii) the beam self-cleaning effect associated with Filamentation, iii) Filamentation in an amplifying medium and iv) organization of multiple filaments by various methods.
Arnaud Couairon - One of the best experts on this subject based on the ideXlab platform.
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Generation of long-lived underdense channels using femtosecond Filamentation in air
Journal of Physics B: Atomic and Molecular Physics, 2015Co-Authors: Guillaume Point, Arnaud Couairon, André Mysyrowicz, Carles Milián, Aurélien HouardAbstract:Using femtosecond laser pulses at 800 and 400 nm, we characterize the formation of underdense channels in air generated by laser Filamentation at the millijoule energy level by means of transverse interferometry. We find that using tight focusing conditions, Filamentation generates a shock wave and that the resulting low-density channel lasts for more than 90 ms. Comparison of these results with hydrodynamic simulations using an Eulerian hydrodynamic code gives an good agreement and allows us to estimate the initial gas peak temperature at ∼ 1000 K. The influence of experimental parameters such as the focusing conditions for the ultrashort laser pulse, its polarization or the wavelength is studied and linked to previous characterizations of Filamentation-generated plasma columns.
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Measurement and control of plasma oscillations in femtosecond filaments
Physical Review Letters, 2011Co-Authors: Bing Zhou, Arnaud Couairon, André Mysyrowicz, Bernard Prade, Aurélien Houard, Yi Liu, Patrick Mora, C. Smeenk, Ladan Arissian, Paul CorkumAbstract:The short-lived longitudinal plasma oscillations generated during Filamentation in argon and nitrogen gas are measured with a specially designed current monitor. The magnitude and initial direction of the corresponding currents depend sensitively on laser polarization and nature of the gas. The results are interpreted as resulting from the competition between two forces acting on free electrons born during the Filamentation process: the Lorentz laser force and a Coulomb wake force resulting from a lateral expansion of the plasma.
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physical characterization of light plasma filaments in water using time resolved shadowgraphy
European Quantum Electronics Conference, 2009Co-Authors: S Minardi, Arnaud Couairon, A Gopal, G Tamosauskas, Rimtautas Piskarskas, A Dubietis, Paolo Di TrapaniAbstract:Filamentation of intense femtosecond laser pulses has recently attracted interest for its potential in applications such as laser-written waveguides in glasses [1] and eye surgery [2]. The evolution of the laser pulse shape and the population of electrons generated during the laser-matter interaction is clearly a key issue for understanding the temporary and permanent physical-chemical changes induced by light Filamentation in the medium, which are particularly relevant for application of light filaments to eye surgery [3].
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Self-focusing and Filamentation of Femtosecond Pulses in Air and Condensed Matter: Simulations and Experiments
Topics in Applied Physics, 2009Co-Authors: Arnaud Couairon, André MysyrowiczAbstract:We review the evolution of the modeling of femtosecond Filamentation in transparent media from the monochromatic self-trapping model to the development of numerical models including all relevant physical effects. We discuss four self-action effects which occur during Filamentation: i) the generation of single cycle pulses by Filamentation in gases, ii) the beam self-cleaning effect associated with Filamentation, iii) Filamentation in an amplifying medium and iv) organization of multiple filaments by various methods.
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Spectrogram representation of pulse self compression by Filamentation
Optics Express, 2008Co-Authors: Selcuk Akturk, Arnaud Couairon, Michel Franco, André MysyrowiczAbstract:We report on numerical simulations and experiments of pulse self-compression by Filamentation. Spectral and temporal evolution during ultrashort-pulse laser Filamentation can be intuitively represented using spectrograms, which display spectra at different time delays of a gate pulse. This representation makes evident the features of self-compression by Filamentation, namely spectral broadening and pulse shortening. In addition, it allows for an analysis of the spectral phase during the nonlinear propagation. In our simulations we observe occurrence of negative chirp over a few cm before the shortest pulse is obtained during Filamentation; this provides an important basis for the understanding of the mechanisms leading to self-compressed filaments. We attribute the negative chirp to spatio-temporal reshaping due to the competition between self-phase modulation and group velocity dispersion. We show that the plasma induced dispersion plays a minor role in establishing the negative chirp.
Michel Franco - One of the best experts on this subject based on the ideXlab platform.
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Spectrogram representation of pulse self compression by Filamentation
Optics Express, 2008Co-Authors: Selcuk Akturk, Arnaud Couairon, Michel Franco, André MysyrowiczAbstract:We report on numerical simulations and experiments of pulse self-compression by Filamentation. Spectral and temporal evolution during ultrashort-pulse laser Filamentation can be intuitively represented using spectrograms, which display spectra at different time delays of a gate pulse. This representation makes evident the features of self-compression by Filamentation, namely spectral broadening and pulse shortening. In addition, it allows for an analysis of the spectral phase during the nonlinear propagation. In our simulations we observe occurrence of negative chirp over a few cm before the shortest pulse is obtained during Filamentation; this provides an important basis for the understanding of the mechanisms leading to self-compressed filaments. We attribute the negative chirp to spatio-temporal reshaping due to the competition between self-phase modulation and group velocity dispersion. We show that the plasma induced dispersion plays a minor role in establishing the negative chirp.
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Femtosecond Filamentation in turbulent air
Physical Review A, 2008Co-Authors: Aurélien Houard, Michel Franco, Bernard Prade, Anne Durécu, Laurent Lombard, Pierre Bourdon, Olivier Vasseur, Bruno Fleury, Clélia Robert, Vincent MichauAbstract:The influence of air turbulence on femtosecond laser Filamentation is studied experimentally and numerically for laser powers of a few critical powers. Air turbulence in the path of the beam prior to Filamentation induces a large pointing and formation instability attributed to an increase of the self-focusing distance and higher modulational instability in the presence of turbulence. By contrast, previously formed filaments are robust both in terms of beam pointing accuracy and survival when crossing turbulent air.
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Pulse shortening, spatial mode cleaning, and intense terahertz generation by Filamentation in xenon
Physical Review A, 2007Co-Authors: Selcuk Akturk, Arnaud Couairon, Michel Franco, Ciro D'amico, André MysyrowiczAbstract:We performed a comprehensive study of Filamentation in xenon. Due to its high nonlinear refraction index, but relatively low ionization potential, xenon can support Filamentation at peak powers lower than in air. In our experiments, we studied pulse shortening, spatial mode cleaning, and generation of terahertz radiation. We observed that in xenon, self-compression is easily obtainable and terahertz radiation generation efficiency is significantly stronger as compared to air.
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Femtosecond Filamentation in air at low pressures. Part II: Laboratory experiments
Optics Communications, 2006Co-Authors: Grégoire Méchain, Arnaud Couairon, Michel Franco, Thomas Olivier, Bernard Prade, André MysyrowiczAbstract:We present experimental studies of Filamentation of a femtosecond laser pulse in air at low pressures. The evolution of the filament has been studied by measuring along the propagation axis the conductivity and the sub-THz emission from the plasma channel. We show experimentally that the Filamentation process occurs at pressures as low as 0.2 atm in agreement with numerical simulations. Experimental and numerical results [A. Couairon, M. Franco, G. Méchain, T. Olivier, B. Prade, A. Mysyrowicz, Opt. Commun., submitted for publication] are compared and the possible sources of discrepancy are discussed.
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Femtosecond Filamentation in air at low pressures: Part I: Theory and numerical simulations
Optics Communications, 2006Co-Authors: Arnaud Couairon, Michel Franco, Grégoire Méchain, Thomas Olivier, Bernard Prade, André MysyrowiczAbstract:We investigate numerically the influence of the pressure on femtosecond Filamentation in air. We show that femtosecond Filamentation occurs at low pressure and compute the features of the plasma channel generated in the wake of the pulse. We discuss the influence of the pulse duration, chirp and input beam shape on the length of the plasma channels. These calculations constitute a prerequisite for laboratory experiments over short distances as well as for vertical femtosecond Filamentation at high altitude on which light detection and ranging techniques or lightning protection rely.
Aurélien Houard - One of the best experts on this subject based on the ideXlab platform.
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Generation of long-lived underdense channels using femtosecond Filamentation in air
Journal of Physics B: Atomic and Molecular Physics, 2015Co-Authors: Guillaume Point, Arnaud Couairon, André Mysyrowicz, Carles Milián, Aurélien HouardAbstract:Using femtosecond laser pulses at 800 and 400 nm, we characterize the formation of underdense channels in air generated by laser Filamentation at the millijoule energy level by means of transverse interferometry. We find that using tight focusing conditions, Filamentation generates a shock wave and that the resulting low-density channel lasts for more than 90 ms. Comparison of these results with hydrodynamic simulations using an Eulerian hydrodynamic code gives an good agreement and allows us to estimate the initial gas peak temperature at ∼ 1000 K. The influence of experimental parameters such as the focusing conditions for the ultrashort laser pulse, its polarization or the wavelength is studied and linked to previous characterizations of Filamentation-generated plasma columns.
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Recent developments in femtosecond Filamentation
Journal of Physics: Conference Series, 2014Co-Authors: Aurélien Houard, Yi Liu, André MysyrowiczAbstract:We review recent developments in the field of femtosecond laser Filamentation.
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kilometer range Filamentation
Optics Express, 2013Co-Authors: Magali Durand, Bernard Prade, Aurélien Houard, Anne Durécu, Olivier Vasseur, A Mysyrowicz, Bernard Moreau, Didier Fleury, Hartmut Borchert, Karsten DienerAbstract:We demonstrate for the first time the possibility to generate long plasma channels up to a distance of 1 km, using the terawatt femtosecond T&T laser facility. The plasma density was optimized by adjusting the chirp, the focusing and beam diameter. The interaction of filaments with transparent and opaque targets was studied.
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Measurement and control of plasma oscillations in femtosecond filaments
Physical Review Letters, 2011Co-Authors: Bing Zhou, Arnaud Couairon, André Mysyrowicz, Bernard Prade, Aurélien Houard, Yi Liu, Patrick Mora, C. Smeenk, Ladan Arissian, Paul CorkumAbstract:The short-lived longitudinal plasma oscillations generated during Filamentation in argon and nitrogen gas are measured with a specially designed current monitor. The magnitude and initial direction of the corresponding currents depend sensitively on laser polarization and nature of the gas. The results are interpreted as resulting from the competition between two forces acting on free electrons born during the Filamentation process: the Lorentz laser force and a Coulomb wake force resulting from a lateral expansion of the plasma.
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Femtosecond Filamentation in turbulent air
Physical Review A, 2008Co-Authors: Aurélien Houard, Michel Franco, Bernard Prade, Anne Durécu, Laurent Lombard, Pierre Bourdon, Olivier Vasseur, Bruno Fleury, Clélia Robert, Vincent MichauAbstract:The influence of air turbulence on femtosecond laser Filamentation is studied experimentally and numerically for laser powers of a few critical powers. Air turbulence in the path of the beam prior to Filamentation induces a large pointing and formation instability attributed to an increase of the self-focusing distance and higher modulational instability in the presence of turbulence. By contrast, previously formed filaments are robust both in terms of beam pointing accuracy and survival when crossing turbulent air.
S L Chin - One of the best experts on this subject based on the ideXlab platform.
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post Filamentation multiple light channel formation in air
Laser Physics, 2014Co-Authors: Hui Gao, Weiwei Liu, S L ChinAbstract:Multiple light channels without ionization have been observed over a long distance at the post-Filamentation stage during the propagation of an intense femtosecond laser pulse in air. It was found that after the Filamentation ended, the laser beam was divided into multiple distinguished millimeter-scale spots surrounded by a larger low energy background. These spots propagated with low divergence, significantly lower than that given by the nonlinear propagation of a laser beam with similar diameter (FWHM) and power. The corresponding numerical simulation reveals that the low intensity energy background plays a dominant role in inducing these multiple light channels at the post-Filamentation stage.
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laser Filamentation induced condensation and snow formation in a cloud chamber
Optics Letters, 2012Co-Authors: Jiansheng Liu, Cheng Wang, Haiyi Sun, Wentao Wang, S L ChinAbstract:Using 1 kHz, 9 mJ femtosecond laser pulses, we demonstrate laser-Filamentation-induced spectacular snow formation in a cloud chamber. An intense updraft of warm moist air is generated owing to the continuous heating by the high-repetition Filamentation. As it encounters the cold air above, water condensation and large-sized particles spread unevenly across the whole cloud chamber via convection and cyclone like action on a macroscopic scale. This indicates that high-repetition Filamentation plays a significant role in macroscopic laser-induced water condensation and snow formation.
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advances in intense femtosecond laser Filamentation in air
Laser Physics, 2012Co-Authors: S L Chin, O G Kosareva, Jiansheng Liu, Tiejun Wang, C Marceau, N A Panov, Yanping Chen, J F Daigle, Shuai Yuan, A AzarmAbstract:This is a review of some recent development in femtosecond Filamentation science with emphasis on our collective work. Previously reviewed work in the field will not be discussed. We thus start with a very brief description of the fundamental physics of single Filamentation of powerful femtosecond laser pulses in air. Intensity clamping is emphasized. One consequence is that the peak intensity inside one or more filaments would not increase significantly even if one focuses the pulse at very high peak power even up to the peta-watt level. Another is that the clamped intensity is independent of pressure. One interesting outcome of the high intensity inside a filament is filament fusion which comes from the nonlinear change of index of refraction inside the filament leading to cross beam focusing. Because of the high intensity inside the filament, one can envisage nonlinear phenomena taking place inside a filament such as a new type of Raman red shift and the generation of very broad band supercontinuum into the infrared through four-wave-mixing. This is what we call by Filamentation nonlinear optics. It includes also terahertz generation from inside the filament. The latter is discussed separately because of its special importance to those working in the field of safety and security in recent years. When the filamenting pulse is linearly polarized, the isotropic nature of air becomes birefringent both electronically (instantaneous) and through molecular wave packet rotation and revival (delayed). Such birefringence is discussed in detailed. Because, in principle, a filament can be projected to a long distance in air, applications to pollution measurement as well as other atmospheric science could be earned out. We call this Filamentation atmospheric science. Thus, the following subjects are discussed briefly, namely, lightning control, rain making, remote measurement of electric field, microwave guidance and remote sensing of pollutants. A discussion on the higher order Kerr effect on the physics of Filamentation is also given. This is a new hot subject of current debate. This review ends on giving our view of the prospect of progress of this field of Filamentation in the future. We believe it hinges upon the development of the laser technology based upon the physical understanding of Filamentation and on the reduction in price of the laser system.
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femtosecond laser Filamentation for atmospheric sensing
Sensors, 2010Co-Authors: S L ChinAbstract:Powerful femtosecond laser pulses propagating in transparent materials result in the formation of self-guided structures called filaments. Such Filamentation in air can be controlled to occur at a distance as far as a few kilometers, making it ideally suited for remote sensing of pollutants in the atmosphere. On the one hand, the high intensity inside the filaments can induce the fragmentation of all matters in the path of filaments, resulting in the emission of characteristic fluorescence spectra (fingerprints) from the excited fragments, which can be used for the identification of various substances including chemical and biological species. On the other hand, along with the femtosecond laser Filamentation, white-light supercontinuum emission in the infrared to UV range is generated, which can be used as an ideal light source for absorption Lidar. In this paper, we present an overview of recent progress concerning remote sensing of the atmosphere using femtosecond laser Filamentation.
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femtosecond laser Filamentation
2009Co-Authors: S L ChinAbstract:Filamentation Physics.- Theory of Single Filamentation.- Multiple Filamentation.- Filamentation Nonlinear Optics: General.- Filamentation Nonlinear Optics: Third Harmonic Generation and Four-Wave-Mixing Inside a Filament.- Remote Sensing Using Filamentation.- Challenges Ahead.
