Dr. Christian Larat Profile

Dr. Christian Larat

Engineer at Thales Research & Technology

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Author

Publications (21)

Proceedings Article | 5 March 2021 Presentation + Paper

61 channels coherent beam combining femtosecond digital laser

Jean-Christophe Chanteloup, Séverine Bellanger, Louis Daniault, Ihsan Fsaifes, Matthieu Veinhard, Jérôme Bourderionnet, Christian Larat, Eric Lallier, Arnaud Brignon

Proceedings Volume 11665, 116651H (2021) https://doi.org/10.1117/12.2576606

KEYWORDS: Femtosecond phenomena, Prototyping, Beam shaping, Structured light, Near field, Composites, Beam controllers

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Proceedings Article | 21 February 2020 Paper

Coherent beam combining of 60 femtosecond fiber amplifiers

Ihsan Fsaifes, Louis Daniault, Séverine Bellanger, Matthieu Veinhard, Jérôme Bourderionnet, Christian Larat, Eric Lallier, Eric Durand, Arnaud Brignon, Jean-Christophe Chanteloup

Proceedings Volume 11260, 112600L (2020) https://doi.org/10.1117/12.2545229

KEYWORDS: Fiber amplifiers, Femtosecond phenomena, Phase measurement, Interferometry, Fiber lasers, Near field, Amplifiers, Laser systems engineering, Collimation, Microlens array

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Proceedings Article | 1 March 2019 Paper

Quantum-based metrology for navigation, radar, and communication applications

G. Baili, P. Berger, A. Brignon, Th. Debuisschert, M. Dupont-Nivet, G. Feugnet, F. Gutty, Ch. Larat, L. Mayer, L. Morvan, P. Nouchi, D. Dolfi

Proceedings Volume 10934, 109342G (2019) https://doi.org/10.1117/12.2516616

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Proceedings Article | 14 May 2018 Paper

100 W-level peak power laser system tunable in the LWIR applied to detection of persistent chemical agents

F. Gutty, A. Grisard, C. Larat, D. Papillon, M. Schwarz, E. Lallier, H. Tholl, F. Münzhuber, J. Kunz, M. Raab, M. Rattunde, Stefan Hugger, Mariusz Kastek, Tadeusz Piatkowski, François Brygo, Cédric Awanzino, Frank Wilsenack

Proceedings Volume 10639, 106392E (2018) https://doi.org/10.1117/12.2304378

KEYWORDS: Standoff detection, Active remote sensing, Pulsed fiber lasers, Fiber amplifiers, Infrared radiation, Nonlinear crystals, Quantum cascade lasers, Optical amplifiers, Long wavelength infrared, Tunable lasers

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Proceedings Article | 30 April 2018 Paper

First results of a QCL-OPA based standoff system, for detecting hazardous substances in the IR-fingerprint domain

Frank Wilsenack, Arne Lorenzen, François Brygo, Cédric Awanzino, F. Gutty, A. Grisard, C. Larat, D. Papillon, M. Schwarz, E. Lallier, Hans Dieter Tholl, Franz Münzhuber, Jürgen Kunz, Michael Raab, Marcel Rattunde, Stefan Hugger, Mariusz Kastek, Tadeusz Piatkowski

Proceedings Volume 10629, 1062902 (2018) https://doi.org/10.1117/12.2314623

KEYWORDS: Absorption, Standoff detection, Reflection, Liquids, Control systems, Laser optics, Chemical weapons, Interfaces, Quantum cascade lasers, Defense and security

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Proceedings Article | 26 February 2018 Paper

Towards coherent combination of 61 fiber amplifiers

Anke Heilmann, Jérémy Le Dortz, Louis Daniault, Ihsan Fsaifes, Séverine Bellanger, Marie Antier, Jérôme Bourderionnet, Christian Larat, Eric Lallier, Eric Durand, Arnaud Brignon, Christophe Simon-Boisson, Jean-Christophe Chanteloup

Proceedings Volume 10512, 105120B (2018) https://doi.org/10.1117/12.2287862

KEYWORDS: Coherent beam combination, Fiber amplifiers, Amplifiers, Phase measurement, Fiber lasers, Femtosecond phenomena

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Proceedings Article | 5 October 2017 Paper

Active multispectral reflection fingerprinting of persistent chemical agents

H. D. Tholl, F. Münzhuber, J. Kunz, M. Raab, M. Rattunde, S. Hugger, F. Gutty, A. Grisard, C. Larat, D. Papillon, M. Schwarz, E. Lallier, M. Kastek, T. Piatkowski, F. Brygo, C. Awanzino, F. Wilsenack, A. Lorenzen

Proceedings Volume 10434, 104340C (2017) https://doi.org/10.1117/12.2277937

KEYWORDS: Quantum cascade lasers, Infrared detectors, Standoff detection, Laser applications, Chemometrics, Infrared radiation, Infrared sensors, Sensors, 3D acquisition

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Proceedings Article | 14 December 2016 Presentation

XCAN project : coherent beam combining of large number fibers in femtosecond regime (Conference Presentation)

Marie Antier, Jeremy Le Dortz, Jerome Bourderionnet, Christian Larat, Eric Lallier, Louis Daniault, Ihsan Fsaifes, Anke Heilmann, Severine Bellanger, Christophe Simon-Boisson, Jean-Christophe Chanteloup, Arnaud Brignon

Proceedings Volume 9992, 99920B (2016) https://doi.org/10.1117/12.2240473

KEYWORDS: Optical fibers, Femtosecond phenomena, Fiber amplifiers, Mode locking, Phase measurement, Phase shifts, Laser development, Beam splitters, Oscillators, Optical amplifiers

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The XCAN project, which is a three years project and began in 2015, carried out by Thales and the Ecole Polytechnique aims at developing a laser system based on the coherent combination of laser beams produced through a network of amplifying optical fibers. This technique provides an attractive mean of reaching simultaneously the high peak and high average powers required for various industrial, scientific and defense applications. The architecture has to be compatible with very large number of fibers (1000-10000). The goal of XCAN is to overcome all the key scientific and technological barriers to the design and development of an experimental laser demonstrator. The coherent addition of multiple individual phased beams is aimed to provide tens of Gigawatt peak power at 50 kHz repetition rate. Coherent beam combining (CBC) of fiber amplifiers involves a master oscillator which is split into N fiber channels and then amplified through series of polarization maintaining fiber pre-amplifiers and amplifiers. In the so-called tiled aperture configuration, the N fibers are arranged in an array and collimated in the near field of the laser output. The N beamlets then interfere constructively in the far field, and give a bright central lobe. CBC techniques with active phase locking involve phase mismatch detection, calculation of the correction and phase compensation of each amplifier by means of phase modulators. Interferometric phase measurement has proven to be particularly well suited to phase-lock a very large number of fibers in continuous regime. A small fraction of the N beamlets is imaged onto a camera. The beamlets interfere separately with a reference beam. The phase mismatch of each beam is then calculated from the interferences’ position. In this presentation, we demonstrate the phase locking of 19 fibers in femtosecond pulse regime with this technique. In our first experiment, a master oscillator generates pulses of 300 fs (chirped at 200 ps). The beam is split into 19 passive channels. Prior to phase locking, the optical path differences are adjusted down to 10 μm with optical delay lines. Interferograms of the 19 fibers are recorded at 1 kHz with a camera. A dedicated algorithm is developed to measure both the phase and the delay between the fibers on a measurement path. The delay and phase shift are thus calculated collectively from a single image and piezo-electric fiber stretchers are controlled in order to ensure compensation of time-varying phase and delay variations. The residual phase shift error is below λ/60 rms. The coherent beam combining is obtained after propagation and compression. The combined pulse width is measured at 315fs. A second experiment was done to coherently combine two amplified channels of the XCAN demonstrator. A residual phase shift error of λ/30 rms was measured in this case.

Proceedings Article | 26 September 2016 Presentation + Paper

Optoelectronic mixing on CVD graphene up to 30 Gigahertz: analysis at high electrostatic doping

A. Montanaro, S. Mzali, J.-P. Mazellier, S. Molin, C. Larat, O. Bezencenet, P. Legagneux

Proceedings Volume 9932, 99320Q (2016) https://doi.org/10.1117/12.2237289

KEYWORDS: Graphene, Optoelectronics, Optoelectronic devices, Chemical vapor deposition, Photodetectors, Standards development, Silicon, Waveguides, Doping, Electronics

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Proceedings Article | 4 March 2015 Paper

Interferometric phase measurement techniques for coherent beam combining

Marie Antier, Jérôme Bourderionnet, Christian Larat, Eric Lallier, Jérôme Primot, Arnaud Brignon

Proceedings Volume 9344, 93441T (2015) https://doi.org/10.1117/12.2076721

KEYWORDS: Phase measurement, Cameras, Fiber amplifiers, Spatial light modulators, Phase shifts, Interferometry, Digital holography, Laser beam diagnostics, Modulators, Holograms

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Proceedings Article | 9 February 2012 Paper

Passive coherent beam combining of quantum-cascade lasers with a Dammann grating

Guillaume Bloom, Christian Larat, Eric Lallier, Gaëlle Lehoucq, Shailendra Bansropun, Mane-Si Laure Lee-Bouhours, Brigitte Loiseaux, Mathieu Carras, Xavier Marcadet, Gaëlle Lucas-Leclin, Patrick Georges

Proceedings Volume 8277, 82771U (2012) https://doi.org/10.1117/12.906717

KEYWORDS: Quantum cascade lasers, Binary data, Coating, Beam splitters, Mid-IR, Polarization, Plasma etching, Mode locking, Antireflective coatings

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Proceedings Article | 5 October 2011 Paper

Coherent combining of quantum-cascade lasers with a binary phase grating

Proceedings Volume 8187, 81870D (2011) https://doi.org/10.1117/12.902136

KEYWORDS: Quantum cascade lasers, Binary data, Coating, Mode locking, Collimation, Beam splitters, Mid-IR, Polarization, Plasma etching

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Proceedings Article | 12 April 2005 Paper

Spatial beam shaping of femtosecond pulses with an optically addressed light valve

Nicolas Sanner, Nicolas Huot, Eric Audouard, Christian Larat, Jean-Pierre Huignard

Proceedings Volume 5708, (2005) https://doi.org/10.1117/12.590353

KEYWORDS: Wavefronts, Femtosecond phenomena, Beam shaping, Light valves, Photovoltaics, Liquid crystals, Micromachining, Phase modulation, Wavefront sensors, Oscillators

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Proceedings Article | 23 December 2004 Paper

High-brightness tapered laser diode bars and optical modules with Al-free active region (lambda = 980 nm)

Michel Krakowski, Michel Calligaro, Christian Larat, Michel Lecomte, Nicolas Michel, Olivier Parillaud, Benoit Boulant, Thierry Fillardet

Proceedings Volume 5620, (2004) https://doi.org/10.1117/12.577514

KEYWORDS: Optical fibers, Semiconductor lasers, Continuous wave operation, Laser dentistry, Beam shaping, Near field optics, Laser vision correction, Laser development, Cladding, Near field

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Proceedings Article | 8 December 2004 Paper

Continuous-wave THz generation through photomixing using a dual-frequency Yb3+:KGd(WO4)2 laser

Romain Czarny, Medhi Alouini, Christian Larat, Sukhdeep Dhillon, Michel Krakowski, Shailendra Bansropun, Valentin Ortiz, Carlo Sirtori, Bruno Gerard, Daniel Dolfi

Proceedings Volume 5619, (2004) https://doi.org/10.1117/12.581285

KEYWORDS: Terahertz radiation, Semiconductor lasers, Antennas, Modulation, Polarization, Continuous wave operation, Indium gallium arsenide, Wave plates, Photoresistors

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Proceedings Article | 11 May 2004 Paper

11-W CW 100-µm fiber-coupled 971-nm Al-free active region pump source

Christian Larat, Sophie-Charlotte Auzanneau, Michel Calligaro, Olivier Parillaud, Michel Krakowski, Benoit Boulant, Arnaud Laugustin, Thierry Fillardet

Proceedings Volume 5365, (2004) https://doi.org/10.1117/12.529069

KEYWORDS: Semiconductor lasers, Beam shaping, Optical fibers, Continuous wave operation, Modeling, Micro optics, Fiber couplers, Optical coatings, Polarization

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Proceedings Article | 18 February 2004 Paper

Programmable femtosecond beam shaping applied to micromachining

Nicolas Sanner, Nicolas Huot, Eric Audouard, Christian Larat, Jerome Bourderionnet, Arnaud Brignon, Pierre Laporte, Jean-Pierre Huignard

Proceedings Volume 5249, (2004) https://doi.org/10.1117/12.515204

KEYWORDS: Femtosecond phenomena, Beam shaping, Micromachining, Wavefronts, Active optics, Control systems, Sensors, Light valves, Adaptive optics, Spatial resolution

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Proceedings Article | 25 March 1996 Paper

High-efficiency intracavity-doubled diode-end-pumped Nd:YVO4 laser

Gilles Feugnet, Claude Bussac, Christian Larat, Muriel Schwarz, Jean-Paul Pocholle

Proceedings Volume 2698, (1996) https://doi.org/10.1117/12.236146

KEYWORDS: Crystals, Neodymium lasers, Nd:YAG lasers, Mirrors, Laser crystals, Solar concentrators, Semiconductor lasers, Coating, Picosecond phenomena, Q switched lasers

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Proceedings Article | 21 August 1995 Paper

High-efficiency TEM00 Nd:YVO4 laser longitudinally pumped by a high-power laser diode array

Gilles Feugnet, Claude Bussac, Christian Larat, Muriel Schwarz, Jean-Paul Pocholle

Proceedings Volume 2538, (1995) https://doi.org/10.1117/12.216980

KEYWORDS: Solar concentrators, Semiconductor lasers, Crystals, Neodymium lasers, Diffraction, Lens design, Mirrors, High power lasers, Diodes, Network on a chip

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Proceedings Article | 20 April 1995 Paper

High-repetition-rate solid state laser for space communications

Christian Larat, Muriel Schwarz, Jean-Paul Pocholle, Gilles Feugnet, Michel Papuchon

Proceedings Volume 2381, (1995) https://doi.org/10.1117/12.207408

KEYWORDS: Pulsed laser operation, Neodymium lasers, Optical amplifiers, Semiconductor lasers, Amplifiers, Modulation, Nd:YAG lasers, Crystals, Diffraction, Absorption

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Proceedings Article | 30 September 1994 Paper

High-repetition rate, short-pulse, diode-pumped solid state laser for space communications

Christian Larat, Muriel Schwarz, Jean-Paul Pocholle, Gilles Feugnet, Michel Papuchon

Proceedings Volume 2210, (1994) https://doi.org/10.1117/12.188114

KEYWORDS: Pulsed laser operation, Nd:YAG lasers, Optical amplifiers, Modulation, Neodymium lasers, Diode pumped solid state lasers, Crystals, Semiconductor lasers, Fiber amplifiers, Telecommunications

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Showing 5 of 21 publications

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