Parametric mid-IR source at high repetition

Ce manuscrit décrit l’étude et la mise en œuvre d’une source laser ultrarapide à taux de répétition élevé dans l’infra-rouge moyen, pour des applications à la physique des champs forts et à la spectroscopie moléculaire multidimensionnelle. Cette source est basée sur le phénomène d’amplification paramétrique optique à dérive de fréquence, qui permet la génération d’impulsions de quelques cycles optiques.Tout d’abord, nous présentons les applications de ces sources, ainsi que leurs paramètres importants, débouchant sur un cahier des charges pour la source à l’étude. Un état de l’art des sources paramétriques présentées dans la littérature scientifique nous permet ensuite d’appréhender la diversité des architectures et des performances atteintes. En particulier, nous soulignons les points cruciaux que sont la nature et les performances du laser de pompe, le mécanisme de génération du signal à amplifier, ainsi que la robustesse de la synchronisation temporelle entre le signal et la pompe.Nous étudions ensuite la possibilité d’émettre un signal autour de la longueur d’onde de 1,55 µm à partir d’impulsions femtoseconde de pompe à 1,03 µm par génération de supercontinuum dans un cristal massif de YAG. Nous menons ainsi une étude détaillée des propriétés de la partie infra-rouge du supercontinuum obtenu, en termes de contenu spectral, cohérence, propriétés statistiques tir à tir et long terme, et propriétés spatiales. Cette étude nous permet de conclure sur la validité de cette approche pour générer le signal à amplifier.Nous arrivons donc à définir une architecture inédite basée sur l’utilisation d’un laser de pompe basé sur un amplificateur à fibre dopée ytterbium de forte énergie délivrant des impulsions de 300 fs 400 µJ à la cadence de 125 kHz. La durée courte rendue possible par le choix de cette technologie de pompe nous permet de bénéficier d’un certain nombre d’avantages importants : la génération efficace de supercontinuum autour de 1,55 µm, ce qui entraine une synchronisation temporelle très robuste entre pompe et signal. D’autre part le couple étireur – compresseur est constitué de simples lames de matériaux massifs, ce qui permet une grande efficacité et une gestion simplifiée de la phase spectrale. Enfin, la courte durée de pompe augmente le seuil de dommage en intensité crête, ce qui permet l’utilisation de cristaux non linéaires courts et augmente la bande spectrale d’amplification. Des expériences supplémentaires sont menées pour étudier les phénomènes limitant la puissance au sein des cristaux de MgO:PPLN. Les étages d’amplification sont tous réalisés en géométrie colinéaire, ce qui permet d’utiliser le signal et l’idler sans introduction de chirp angulaire. Toutes ces caractéristiques permettent la génération de deux faisceaux en sortie portant des impulsions de 50 fs 20 µJ à 1550 nm et 70 fs 10 µJ à 3,1 µm.This thesis describes the design and construction of an ultrafast high repetition rate laser source in the mid-IR, for applications in strong-field physics and multidimensional molecular spectroscopy. This source is based on optical parametric chirped-pulse amplification, allowing the generation of few-cycle pulses.We first present some applications of these lasers, along with important parameters, to define specifications for the considered source. We then briefly outline the state of the art of similar ultrafast sources described in the literature, to highlight the variety of architectures and performances. In particular, several key points are identified, namely the nature and performances of the pump laser source, the method to generate a seeding signal, and the robustness of temporal synchronization between pump and signal pulses.We proceed to study the possibility of emitting a seed signal around 1.55 µm wavelength by supercontinuum generation in a bulk YAG crystal from femtosecond pump pulses at 1.03 µm. A detailed analysis of the properties of the infrared spectral content of the supercontinuum is carried out, focusing on spectral bandwidth, coherence, shot-to-shot and long term stability, and spatial properties. This work allows us to conclude that supercontinuum generation is a valid approach to generate the seed signal.This leads us to define a novel architecture built around an ytterbium-doped fiber femtosecond pump source delivering 300 fs 400 µJ pulses at a repetition rate 125 kHz. The short pump pulse duration compared to bulk Yb:YAG or Nd:YVO4 based systems results in a number of important advantages. First, it allows efficient seeding at 1550 nm using supercontinuum generation directly from the pump pulses in a bulk YAG crystal, resulting in extremely robust passive pump – signal synchronization. The short pump pulse duration also allows the use of millimeter to centimeter lengths of bulk materials to provide stretching and compression for the signal and idler, which minimizes the accumulation of higher-order spectral phase. Finally, the shorter pump pulse duration increases the damage peak intensity, permitting the use of shorter nonlinear crystals to perform the amplification, which increases the spectral bandwidth of the parametric process. Additional experiments are performed to sort out the phenomena that limit power scaling in MgO:PPLN crystals. The OPCPA stages are all operated in collinear geometry, allowing the use of both signal and idler without the introduction of angular chirp on the latter. These points result in the dual generation of 70 fs 23 µJ signal pulses at 1550 nm and 60 fs 10 µJ idler pulses at 3070 nm from a simple setup

Source paramétrique dans l'infrarouge moyen à haute cadence

This thesis describes the design and construction of an ultrafast high repetition rate laser source in the mid-IR, for applications in strong-field physics and multidimensional molecular spectroscopy. This source is based on optical parametric chirped-pulse amplification, allowing the generation of few-cycle pulses.We first present some applications of these lasers, along with important parameters, to define specifications for the considered source. We then briefly outline the state of the art of similar ultrafast sources described in the literature, to highlight the variety of architectures and performances. In particular, several key points are identified, namely the nature and performances of the pump laser source, the method to generate a seeding signal, and the robustness of temporal synchronization between pump and signal pulses.We proceed to study the possibility of emitting a seed signal around 1.55 µm wavelength by supercontinuum generation in a bulk YAG crystal from femtosecond pump pulses at 1.03 µm. A detailed analysis of the properties of the infrared spectral content of the supercontinuum is carried out, focusing on spectral bandwidth, coherence, shot-to-shot and long term stability, and spatial properties. This work allows us to conclude that supercontinuum generation is a valid approach to generate the seed signal.This leads us to define a novel architecture built around an ytterbium-doped fiber femtosecond pump source delivering 300 fs 400 µJ pulses at a repetition rate 125 kHz. The short pump pulse duration compared to bulk Yb:YAG or Nd:YVO4 based systems results in a number of important advantages. First, it allows efficient seeding at 1550 nm using supercontinuum generation directly from the pump pulses in a bulk YAG crystal, resulting in extremely robust passive pump – signal synchronization. The short pump pulse duration also allows the use of millimeter to centimeter lengths of bulk materials to provide stretching and compression for the signal and idler, which minimizes the accumulation of higher-order spectral phase. Finally, the shorter pump pulse duration increases the damage peak intensity, permitting the use of shorter nonlinear crystals to perform the amplification, which increases the spectral bandwidth of the parametric process. Additional experiments are performed to sort out the phenomena that limit power scaling in MgO:PPLN crystals. The OPCPA stages are all operated in collinear geometry, allowing the use of both signal and idler without the introduction of angular chirp on the latter. These points result in the dual generation of 70 fs 23 µJ signal pulses at 1550 nm and 60 fs 10 µJ idler pulses at 3070 nm from a simple setup.Ce manuscrit décrit l’étude et la mise en œuvre d’une source laser ultrarapide à taux de répétition élevé dans l’infra-rouge moyen, pour des applications à la physique des champs forts et à la spectroscopie moléculaire multidimensionnelle. Cette source est basée sur le phénomène d’amplification paramétrique optique à dérive de fréquence, qui permet la génération d’impulsions de quelques cycles optiques.Tout d’abord, nous présentons les applications de ces sources, ainsi que leurs paramètres importants, débouchant sur un cahier des charges pour la source à l’étude. Un état de l’art des sources paramétriques présentées dans la littérature scientifique nous permet ensuite d’appréhender la diversité des architectures et des performances atteintes. En particulier, nous soulignons les points cruciaux que sont la nature et les performances du laser de pompe, le mécanisme de génération du signal à amplifier, ainsi que la robustesse de la synchronisation temporelle entre le signal et la pompe.Nous étudions ensuite la possibilité d’émettre un signal autour de la longueur d’onde de 1,55 µm à partir d’impulsions femtoseconde de pompe à 1,03 µm par génération de supercontinuum dans un cristal massif de YAG. Nous menons ainsi une étude détaillée des propriétés de la partie infra-rouge du supercontinuum obtenu, en termes de contenu spectral, cohérence, propriétés statistiques tir à tir et long terme, et propriétés spatiales. Cette étude nous permet de conclure sur la validité de cette approche pour générer le signal à amplifier.Nous arrivons donc à définir une architecture inédite basée sur l’utilisation d’un laser de pompe basé sur un amplificateur à fibre dopée ytterbium de forte énergie délivrant des impulsions de 300 fs 400 µJ à la cadence de 125 kHz. La durée courte rendue possible par le choix de cette technologie de pompe nous permet de bénéficier d’un certain nombre d’avantages importants : la génération efficace de supercontinuum autour de 1,55 µm, ce qui entraine une synchronisation temporelle très robuste entre pompe et signal. D’autre part le couple étireur – compresseur est constitué de simples lames de matériaux massifs, ce qui permet une grande efficacité et une gestion simplifiée de la phase spectrale. Enfin, la courte durée de pompe augmente le seuil de dommage en intensité crête, ce qui permet l’utilisation de cristaux non linéaires courts et augmente la bande spectrale d’amplification. Des expériences supplémentaires sont menées pour étudier les phénomènes limitant la puissance au sein des cristaux de MgO:PPLN. Les étages d’amplification sont tous réalisés en géométrie colinéaire, ce qui permet d’utiliser le signal et l’idler sans introduction de chirp angulaire. Toutes ces caractéristiques permettent la génération de deux faisceaux en sortie portant des impulsions de 50 fs 20 µJ à 1550 nm et 70 fs 10 µJ à 3,1 µm

High repetition rate mid-IR few-cycle source based on optical parametric chirped pulse amplification (MIR OPCPA project)

Conseil Scientifique International du Labex PALM, Feb 2015, Palaiseau, Franc

Supercontinuum-seeded few-cycle mid-infrared OPCPA system

International audienc

High power mid-IR OPCPA system pumped by a femtosecond Yb-doped fiber amplifier (orale)

International audienc

LISA AIVT Optical Ground Support Equipement technology developments

International audienceThe LISA space interferometer aims at GW detection with »3x10-20/√Hz strain sensitivity, resulting in a displacement sensitivity of 11pm/√Hz over a path length of 2.5x109 m in the frequency range from 3x10-5 to 1 Hz.The LISA France Collaboration is in charge of the ground optical tests of the MOSA (Moving Optical Sub-Assembly), including the Optical Bench, Telescope and Gravitational Reference Sensor. Special check-out equipment is required, such as the Far-Field Optical Ground Support Equipment aiming at measuring the Tilt-To-Length coupling coefficient between angular residual beam jitter and longitudinal path length. The FF-OGSE simulates the incoming jittering beam and measures the associated longitudinal path length change.We present two prototypes – the Zerodur InterFerOmeter and the TTL-OB - that will demonstrate the optical performance, the functional tests, the limits on sensitivity and the precision of the path length measurements achievable on-ground. These two benches are the first part of the design and specification for the FF-OGSE.The Stray Light OGSE aims at stray light characterization in the integrated MOSA. It measures and identifies, separately, the different sources of stray light through the measurement of the corresponding fringe patterns while scanning the laser’s optical frequency

LISA AIVT Optical Ground Support Equipement technology developments

International audienceThe LISA space interferometer aims at GW detection with »3x10-20/√Hz strain sensitivity, resulting in a displacement sensitivity of 11pm/√Hz over a path length of 2.5x109 m in the frequency range from 3x10-5 to 1 Hz.The LISA France Collaboration is in charge of the ground optical tests of the MOSA (Moving Optical Sub-Assembly), including the Optical Bench, Telescope and Gravitational Reference Sensor. Special check-out equipment is required, such as the Far-Field Optical Ground Support Equipment aiming at measuring the Tilt-To-Length coupling coefficient between angular residual beam jitter and longitudinal path length. The FF-OGSE simulates the incoming jittering beam and measures the associated longitudinal path length change.We present two prototypes – the Zerodur InterFerOmeter and the TTL-OB - that will demonstrate the optical performance, the functional tests, the limits on sensitivity and the precision of the path length measurements achievable on-ground. These two benches are the first part of the design and specification for the FF-OGSE.The Stray Light OGSE aims at stray light characterization in the integrated MOSA. It measures and identifies, separately, the different sources of stray light through the measurement of the corresponding fringe patterns while scanning the laser’s optical frequency

LISA AIVT Optical Ground Support Equipement technology developments

International audienceThe LISA space interferometer aims at GW detection with »3x10-20/√Hz strain sensitivity, resulting in a displacement sensitivity of 11pm/√Hz over a path length of 2.5x109 m in the frequency range from 3x10-5 to 1 Hz.The LISA France Collaboration is in charge of the ground optical tests of the MOSA (Moving Optical Sub-Assembly), including the Optical Bench, Telescope and Gravitational Reference Sensor. Special check-out equipment is required, such as the Far-Field Optical Ground Support Equipment aiming at measuring the Tilt-To-Length coupling coefficient between angular residual beam jitter and longitudinal path length. The FF-OGSE simulates the incoming jittering beam and measures the associated longitudinal path length change.We present two prototypes – the Zerodur InterFerOmeter and the TTL-OB - that will demonstrate the optical performance, the functional tests, the limits on sensitivity and the precision of the path length measurements achievable on-ground. These two benches are the first part of the design and specification for the FF-OGSE.The Stray Light OGSE aims at stray light characterization in the integrated MOSA. It measures and identifies, separately, the different sources of stray light through the measurement of the corresponding fringe patterns while scanning the laser’s optical frequency

LISA AIVT Optical Ground Support Equipement technology developments

International audienceThe LISA space interferometer aims at GW detection with »3x10-20/√Hz strain sensitivity, resulting in a displacement sensitivity of 11pm/√Hz over a path length of 2.5x109 m in the frequency range from 3x10-5 to 1 Hz.The LISA France Collaboration is in charge of the ground optical tests of the MOSA (Moving Optical Sub-Assembly), including the Optical Bench, Telescope and Gravitational Reference Sensor. Special check-out equipment is required, such as the Far-Field Optical Ground Support Equipment aiming at measuring the Tilt-To-Length coupling coefficient between angular residual beam jitter and longitudinal path length. The FF-OGSE simulates the incoming jittering beam and measures the associated longitudinal path length change.We present two prototypes – the Zerodur InterFerOmeter and the TTL-OB - that will demonstrate the optical performance, the functional tests, the limits on sensitivity and the precision of the path length measurements achievable on-ground. These two benches are the first part of the design and specification for the FF-OGSE.The Stray Light OGSE aims at stray light characterization in the integrated MOSA. It measures and identifies, separately, the different sources of stray light through the measurement of the corresponding fringe patterns while scanning the laser’s optical frequency

LISA AIVT Optical Ground Support Equipement technology developments

International audienceThe LISA space interferometer aims at GW detection with »3x10-20/√Hz strain sensitivity, resulting in a displacement sensitivity of 11pm/√Hz over a path length of 2.5x109 m in the frequency range from 3x10-5 to 1 Hz.The LISA France Collaboration is in charge of the ground optical tests of the MOSA (Moving Optical Sub-Assembly), including the Optical Bench, Telescope and Gravitational Reference Sensor. Special check-out equipment is required, such as the Far-Field Optical Ground Support Equipment aiming at measuring the Tilt-To-Length coupling coefficient between angular residual beam jitter and longitudinal path length. The FF-OGSE simulates the incoming jittering beam and measures the associated longitudinal path length change.We present two prototypes – the Zerodur InterFerOmeter and the TTL-OB - that will demonstrate the optical performance, the functional tests, the limits on sensitivity and the precision of the path length measurements achievable on-ground. These two benches are the first part of the design and specification for the FF-OGSE.The Stray Light OGSE aims at stray light characterization in the integrated MOSA. It measures and identifies, separately, the different sources of stray light through the measurement of the corresponding fringe patterns while scanning the laser’s optical frequency