The objective of this dissertation is to generate high power ultrashort optical pulses from an all-semiconductor mode-locked laser system. The limitations of semiconductor optical amplifier in high energy, ultrashort pulse amplification are reviewed. A method to overcome the fundamental limit of small stored energy inside semiconductor optical amplifier called "eXtreme Chirped Pulse Amplification (X-CPA)" is proposed and studied theoretically and experimentally. The key benefits of the concept of X-CPA are addressed. Based on theoretical and experimental study, an all-semiconductor mode-locked X-CPA system consisting of a mode-locked master oscillator, an optical pulse pre-stretcher, a semiconductor optical amplifier (SOA) pulse picker, an extreme pulse stretcher/compressor, cascaded optical amplifiers, and a bulk grating compressor is successfully demonstrated and generates >kW record peak power. A potential candidate for generating high average power from an X-CPA system, novel grating coupled surface emitting semiconductor laser (GCSEL) devices, are studied experimentally. The first demonstration of mode-locking with GCSELs and associated amplification characteristics of grating coupled surface emitting SOAs will be presented. In an effort to go beyond the record setting results of the X-CPA system, a passive optical cavity amplification technique in conjunction with the X-CPA system is constructed, and studied experimentally and theoretically.

We demonstrate four experimentally simple methods for measuring very complex ultrashort light pulses. Although each method is comprised of only a few optical elements, they permit the measurement of extremely complex pulses with time-bandwidth products greater than 65,000. First, we demonstrate an extremely simple frequency-resolved-optical gating (GRENOUILLE) device for measuring the intensity and phase of pulses up to ~20ps in length. In order to achieve the required high spectral resolution and large temporal range, it uses a few-cm-thick second harmonic-generation crystal in the shape of a pentagon. This has the additional advantage of reducing the device's total number of components to three. Secondly, we introduce a variation of spectral interferometry (SI) using a virtually imaged phased array and grating spectrometer for measuring long complex ultrashort pulses up to 80 ps in length. Next, we introduce a SI technique for measuring the complete intensity and phase of relatively long and very complex ultrashort pulses. It involves making multiple measurements using SI (in its SEA TADPOLE variation) at numerous delays, measuring many temporal pulselets within the pulse, and concatenating the resulting pulselets. Its spectral resolution is the inverse delay range--many times higher than that of the spectrometer used. The waveforms were measured with ~ fs temporal resolution over a temporal range of ~ns and had time-bandwidth products exceeding 65,000, which to our knowledge is the largest time-bandwidth product ever measured with ~fs temporal resolution. Finally, we demonstrate a single-shot measurement technique that temporally interleaves hundreds of measurements with ~fs temporal resolution. It is another variation of SI for measuring the complete intensity and phase of relatively long and complex ultrashort pulses in a single shot. It uses a grating to introduce a transverse time delay into a reference pulse which gates the unknown pulse by interfering it at the image plane of an imaging spectrometer. It provided ~125 fs temporal resolution and a temporal range of 70 ps using a low-resolution spectrometer.

The ultrashort chirped pulse amplification (CPA) laser technology opens the path to high intensities of 10^21 W/cm² and above in the laser focus. Such intensities allow laser-matter interaction in the relativistic intensity regime. Direct diode-pumped ultrashort solid-state lasers combine high-energy, high-power and efficient amplification together, which are the main advantages compared to flashlamp-pumped high-energy laser systems based on titanium-doped sapphire. Development within recent years in the field of laser diodes makes them more and more attractive in terms of total costs, compactness and lifetime. This work is dedicated to the Petawatt, ENergy-Efficient Laser for Optical Plasma Experiments (PENELOPE) project, a fully and directly diode-pumped laser system under development at the Helmholtz–Zentrum Dresden – Rossendorf (HZDR), aiming at 150 fs long pulses with energies of up to 150 J at repetition rates of up to 1 Hz. The focus of this thesis lies on the spectral and width manipulation of the front-end amplifiers, trivalent ytterbium-doped calcium fluoride (Yb3+:CaF2) as gain material as well as the pump source for the final two main amplifiers of the PENELOPE laser system. Here, all crucial design parameters were investigated and a further successful scaling of the laser system to its target values was shown. Gain narrowing is the dominant process for spectral bandwidth reduction during the amplification at the high-gain front-end amplifiers. Active or passive spectral gain control filter can be used to counteract this effect. A pulse duration of 121 fs was achieved by using a passive spectral attenuation inside a regenerative amplifier, which corresponds to an improvement by a factor of almost 2 compared to the start of this work. A proof-of-concept experiment showed the capability of the pre-shaping approach. A spectral bandwidth of 20nm was transferred through the first multipass amplifier at a total gain of 300. Finally, the predicted output spectrum calculated by a numerical model of the final amplifier stages was in a good agreement with the experimental results. The spectroscopic properties of Yb3+:CaF2 matches the constraints for ultrashort laser pulse amplification and direct diode pumping. Pumping close to the zero phonon line at 976nm is preferable compared to 940nm as the pump intensity saturation is significantly lower. A broad gain cross section of up to 50nm is achievable for typical inversion levels. Furthermore, moderate cryogenic temperatures (above 200K) can be used to improve the amplification performance of Yb3+:CaF2. The optical quality of the doped crystals currently available on the market is sufficient to build amplifiers in the hundred joule range. The designed pump source for the last two amplifiers is based on two side pumping in a double pass configuration. However, this concept requires the necessity of brightness conservation for the installed laser diodes. Therefore, a fully relay imaging setup (4f optical system) along the optical path from the stacks to the gain material including the global beam homogenization was developed in a novel approach. Beside these major parts the amplifier architecture and relay imaging telescopes as well as temporal intensity contrast (TIC) was investigated. An all reflective concept for the relay imaging amplifiers and telescopes was selected, which results in several advantages especially an achromatic behavior and low B-Integral. The TIC of the front-end was improved, as the pre- and postpulses due to the plane-parallel active-mirror was eliminated by wedging the gain medium.

The ultrashort chirped pulse amplification (CPA) laser technology opens the path to high intensities of 10^21 W/cm² and above in the laser focus. Such intensities allow laser-matter interaction in the relativistic intensity regime. Direct diode-pumped ultrashort solid-state lasers combine high-energy, high-power and efficient amplification together, which are the main advantages compared to flashlamp-pumped high-energy laser systems based on titanium-doped sapphire. Development within recent years in the field of laser diodes makes them more and more attractive in terms of total costs, compactness and lifetime. This work is dedicated to the Petawatt, ENergy-Efficient Laser for Optical Plasma Experiments (PENELOPE) project, a fully and directly diode-pumped laser system under development at the Helmholtz–Zentrum Dresden – Rossendorf (HZDR), aiming at 150 fs long pulses with energies of up to 150 J at repetition rates of up to 1 Hz. The focus of this thesis lies on the spectral and width manipulation of the front-end amplifiers, trivalent ytterbium-doped calcium fluoride (Yb3+:CaF2) as gain material as well as the pump source for the final two main amplifiers of the PENELOPE laser system. Here, all crucial design parameters were investigated and a further successful scaling of the laser system to its target values was shown. Gain narrowing is the dominant process for spectral bandwidth reduction during the amplification at the high-gain front-end amplifiers. Active or passive spectral gain control filter can be used to counteract this effect. A pulse duration of 121 fs was achieved by using a passive spectral attenuation inside a regenerative amplifier, which corresponds to an improvement by a factor of almost 2 compared to the start of this work. A proof-of-concept experiment showed the capability of the pre-shaping approach. A spectral bandwidth of 20nm was transferred through the first multipass amplifier at a total gain of 300. Finally, the predicted output spectrum calculated by a numerical model of the final amplifier stages was in a good agreement with the experimental results. The spectroscopic properties of Yb3+:CaF2 matches the constraints for ultrashort laser pulse amplification and direct diode pumping. Pumping close to the zero phonon line at 976nm is preferable compared to 940nm as the pump intensity saturation is significantly lower. A broad gain cross section of up to 50nm is achievable for typical inversion levels. Furthermore, moderate cryogenic temperatures (above 200K) can be used to improve the amplification performance of Yb3+:CaF2. The optical quality of the doped crystals currently available on the market is sufficient to build amplifiers in the hundred joule range. The designed pump source for the last two amplifiers is based on two side pumping in a double pass configuration. However, this concept requires the necessity of brightness conservation for the installed laser diodes. Therefore, a fully relay imaging setup (4f optical system) along the optical path from the stacks to the gain material including the global beam homogenization was developed in a novel approach. Beside these major parts the amplifier architecture and relay imaging telescopes as well as temporal intensity contrast (TIC) was investigated. An all reflective concept for the relay imaging amplifiers and telescopes was selected, which results in several advantages especially an achromatic behavior and low B-Integral. The TIC of the front-end was improved, as the pre- and postpulses due to the plane-parallel active-mirror was eliminated by wedging the gain medium.

The present thesis shows how versatile and important the field of gas-phase spectroscopy under supersonic expansion conditions can be to understand fundamental intermolecular and intramolecular interactions. We have employed spectroscopic techniques over a very broad range spanning from microwave (2-18 GHz), through infrared (2600-4000 cm-1) and ultraviolet (350-250 nm) region, studying therotational, vibrational and electronic properties,respectively. These techniques use either chirped-pulse based (broadband rotational spectroscopy) or laser based methods (vibrational and electronic spectroscopy), and their usage depends on the types of information of particular interest and the chemical system requirements of specific techniques. The analytes are brought into the gas phase and supersonically cooled to their zero-point vibrational level to perform rotational and vibrationallyresolved IR/UV spectroscopy, including conformer-specific techniques. The variety of small organic molecular systemsstudied include phenyl-containing hydrocarbons, water containing clusters, heteroatom containing organic molecules with and without phenyl ring, fused aromatic molecules, bichromophoric molecules and pyrolysis reaction intermediates. Apart from gaining invaluable fundamental knowledge of the various interactions, we also observe interesting quantum-physical phenomena like tunneling and large amplitude motions that provide further insight into the molecular world.

Les impulsions ultra-brèves de rayonnement ultraviolet extrême (UVX) ont un grand champ d’application dans les domaines tels que le diagnostic de plasmas, la spectroscopie ou l’étude de la dynamique ultrarapide dans les atomes et les molécules.Aujourd’hui, il existe trois sources délivrant ce genre d’impulsions. Les harmoniques d’ordre élevé (HHG, en anglais) générés dans les gaz rares ou sur les solides peuvent fournir des impulsions attosecondes. Cependant, leur énergie, le plus souvent de l’ordre du nanojoule, limite les applications. L’amplification des impulsions harmoniques dans les plasmas créés par laser (SXRL, en anglais) a démontré pouvoir fournir des énergies de plusieurs dizaines de microjoules. Des énergies plus élevées peuvent être obtenues avec les lasers à électrons libres (LEL) UVX injectés, mais ce sont des Très Grandes Infrastructures ayant un accès limité.Ces dernières années, des progrès significatifs ont été réalisé avec chacune des ces sources, avec pour objectif la génération d’impulsions plus brèves. Il est devenu nécessaire de développer des nouvelles techniques de métrologie temporelle des impulsions UVX ultra-brèves. De plus, beaucoup d’expériences, comme ceux impliquant des phénomènes non-linéaires, nécessitent de hautes intensités UVX. La focalisation efficace des impulsions de faibles énergies peut significativement augmenter le domaine d’application. De bons fronts d’onde sont nécessaires pour focaliser les impulsions UVX à haute intensité, et les optiques doivent aussi être de bonne qualité et alignées avec précision.Dans cette thèse, les propriétés spatiales des harmoniques d’ordre élevé ont été extensivement étudiées grâce à un senseur de front d’onde UVX. Cet appareil couplé à une source HHG a démontré être utile pour la caractérisation de table et à la longueur d’onde ainsi que pour l’optimisation de systèmes optiques UVX.Le problème de la mise en place de la complète caractérisation temporelle d’impulsions UVX est aussi discuté en détail, et deux nouveaux schémas pour la reconstruction d’impulsions de LEL injectés et de lasers X à plasma sont présentés. Finalement, la première implantation d’un système d’amplification à dérive de fréquence (CPA, en anglais) sur un LEL UVX est présentée et son implantation pour les lasers X à plasmas est aussi discutée. / Ultrashort pulses of extreme-ultraviolet (XUV) radiation have a wide range of applications in fields such as plasma probing, spectroscopy, or the study of ultrafast dynamics in atoms and molecules.Nowadays, there are three main sources of such pulses. High-order harmonic generation (HHG) in rare gases or solid surfaces is able to provide attosecond pulses. However, their limited energy, of the order of nanojoules, limits its number of applications. The amplification of high-harmonic pulses in laser-driven plasmas (SXRL) has been demonstrated to provide energies of tens of microjules. Higher pulse energies can be obtained from seeded XUV free-electron lasers (FELs), large-scale facilities with more limited accessibility.In recent years, significant progress has been made with each of these sources towards the generation of shorter pulses. It is thus necessary to develop new techniques for full temporal metrology of ultrashort XUV pulses. Additionally, many experiments, such as those involving nonlinear phenomena, require high XUV intensities. Efficient focusing of low-energy pulses can significantly increase their range of application. Good wavefronts are required in order to focus XUV pulses to high intensities, and the optics must be of high quality and precisely aligned.In this thesis, the spatial properties of high-harmonic pulses are extensively explored thanks to the use of an XUV Hartmann wavefront sensor. This device is also proven here to be useful for tabletop, at-wavelength characterization and optimization of XUV optical systems with HHG sources.The problem of performing full temporal characterization of XUV pulses is also discussed in detail, and two new schemes for complete pulse reconstruction for seeded XUV FELs and seeded SXRLs are presented. Finally, the first implementation of chirped pulse amplification (CPA) in a seeded XUV FEL is reported, and its implementation in seeded SXRLs is discussed as well.

La nécessité de prouver l’existence de nouvelles particules comme les quarks et le boson de Higgs a entrainé le développement de deux nouveaux pans de la recherche : la physique des hautes énergies ou physique des particules, dédiée à prouver expérimentalement l'existence de ces particules puis à étudier leurs propriétés et la physique des accélérateurs, dédiée au développement de nouveaux instruments pour la physique des hautes énergies.Dans ce contexte, des collisionneurs linéaires électrons/positrons polarisés de forte luminosité dont l'énergie serait connue et accordable pourrait permettre d’étudier plus finement des particules se situant dans des énergies autour du TeV telles que le Boson de Higgs. C'est dans ce sens que le projet International Linear Collider (ILC) est conçu et c'est dans le cadre du développement de ce collisionneur linéaire de particules que cette thèse de doctorat se situe. Un des points critiques de l'ILC est la source de positrons polarisés. Sans entrer dans des explications sur la physique du processus de création de positrons polarisés, nous précisons simplement que ceux-ci sont créés lorsque des rayons gamma polarisés circulairement interagissent avec la matière. Le point critique est donc la source de rayons gamma polarisés circulairement. Une alternative pour cette source est la diffusion Compton inverse et c'est finalement dans le cadre de la recherche et du développement de systèmes lasers de fortes puissances moyennes asservis à des cavités Fabry-Perot pour la production de rayons gamma polarisés par diffusion Compton inverse que se situe cette thèse.Dans un premier temps, nous posons plus précisément le contexte de cette thèse, le principe de la diffusion Compton inverse ainsi que le choix d’une architecture optique basée sur un laser fibré et une cavité Fabry-Perot. Nous finissons sur une énumération des différentes applications possibles de la diffusion Compton inverse montrant que les travaux présentés pourraient bénéficier de transfert technologique vers d’autres domaines. Dans un second temps, nous présentons les différentes architectures d’amplification laser fibrée étudiées ainsi que les résultats obtenus. Dans un troisième temps, nous faisons un rappel du principe de fonctionnement d’une cavité Fabry-Perot et présentons celle utilisée pour notre expérience ainsi que ses spécificités. Dans un quatrième temps, nous abordons l’expérience de diffusion Compton inverse qui nous a permis de présenter pour la première fois à notre connaissance l’utilisation conjointe d’un laser à fibre optique et d’une cavité Fabry-Perot dans le cadre d’un accélérateur de particules pour générer des rayons gamma. Le dispositif expérimental ainsi que les résultats obtenus sont alors présentés. Finalement, nous résumons les résultats présentés dans ce manuscrit et proposons différentes possibilités d’évolution pour le système dans une conclusion générale. / The requirement to prove the existence of news particles like quarks and the Higgs boson has led the development of two news branches for the research: the high energy physics or particle physics, dedicated to experimentally prove the existence of these new particles then to study their properties and the accelerator physics, dedicated to develop particles accelerators for the high energy physic. In this context, polarized electrons/positrons high luminosity linear collider of known and scalable energy might enable more precise studies of particles with energy around the TeV such as the Higgs boson. To that end, the International Linear Collider (ILC) project is being designed and it is in this framework that this PhD thesis takes place. One of the critical points of the ILC is the polarized positrons source. Without going through further explanation on the physical process of polarized positrons production, we point out that they are produced when circularly polarized gamma rays interact with mater. Thus, the critical point is the circularly polarized gamma-ray source. A technical solution for this source is the Compton backscattering and in the end, this thesis takes place in the framework of R&D for high average power laser systems enslaved to Fabry-Perot cavities for polarized gamma-ray production by Compton backscattering. In the first part, we present this thesis context, the Compton backscattering principle and the choice for an optical architecture based on a fiber laser and a Fabry-Perot cavity. We finish by enumerating several possible applications for Compton backscattering which shows that the work presented here might benefits from technology transfer through others research fields. In the second part, we present the different fiber laser architecture studied as well as the results obtained. In the third part, we remind the operating principle of a Fabry-Perot cavity and present the one used for our experiment as well as its specificities. In the fourth part, we address the Compton backscattering experiment which enables us to present the joint utilization of a fiber laser and a Fabry-Perot cavity in a particles accelerator to generate gamma rays for the first time to our knowledge. The experimental apparatus as well as the results obtained are thus presented. In the end, we summarize the results presented in this manuscript and propose different evolution possibilities for the system in a general conclusion.

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