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Jumpertz, Louise. "Photonique non-linéaire dans les lasers à cascade quantique moyen infrarouges". Electronic Thesis or Diss., Paris, ENST, 2016. https://pastel.hal.science/tel-03689516.
Pełny tekst źródłaMid-infrared quantum cascade lasers are unipolar semiconductor lasers, which have become widely used sources for applications such as gas spectroscopy, free-space communications or optical countermeasures. Applying external per-turbations such as optical feedback or optical injection leads to a strong modification of the quantum cascade laser prop-erties. Optical feedback impacts the static properties of mid-infrared Fabry-Perot and distributed feedback quantum cas-cade lasers, inducing power increase, threshold reduction, modification of the optical spectrum, which can become either single- or multimode, and enhanced beam quality of broad-area transverse multimode lasers. It also leads to a different dynamical behavior, and a quantum cascade laser subject to optical feedback can oscillate periodically or even become chaotic: this work provides the very first analysis of optical instabilities in the mid-infrared range. A numerical study of optical injection furthermore proves that quantum cascade lasers can injection-lock over a few gigahertz, where they should experience enhanced stability and especially improved modulation bandwidth. Furthermore, some promising dynamics appear outside the locking range with periodic oscillations at a tunable frequency or high-intensity events. A quantum cascade laser under external control could therefore be a source with enhanced properties for the usual mid-infrared applications, but could also address new applications such as tunable photonic oscillators, extreme events gen-erators, chaotic LIDAR, chaos-based secured communications or unpredictable countermeasures
Dory, Jean-Baptiste. "Matériaux chalcogénures innovants pour l’optique non linéaire intégrée dans le moyen infra rouge". Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCK075.
Pełny tekst źródłaElaboration and characterization of new compositions of chalcogenide materials exhibiting nonlinear effects for integrated optic applications and fabrication of low-loss waveguides
Heidmann, Samuel. "Composants actifs en optique intégrée pour l'interférométrie stellaire dans le moyen infrarouge". Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENT096/document.
Pełny tekst źródłaThe observation of exoplanets and more generally of the close environment of young stars represents an observational double difficulty : the small angular separation between the star and the planet (or its environment such as a protoplanetary disk) and contrast flux. One technique to overcome these difficulties is the nulling interferometry. Two telescopes target a star planet/disk system and the pupils are recombined in such a way that the photons from the star cause destructive interference while those from the planet/disk cause constructive interference. Instrumental constraints are very strong to ensure sufficient extinction of the star, both in terms of optical path difference (of the order of nanometers) than photometric balance (4% for a minimum extinction ratio 40dB). L-band (3.4-4.1μm) is adapted to the observation of cold matter, because the flux ratio between the planet (or star dust) and the star presents a minimum of 10−4 order after 3μm, making the L-band particularly attractive for such observations. Because silicates and glass are not suitable to build guides reaching the L-band, there is currently no mature instrument in this band in integrated optics. Indeed, instrumental constraints on nulling interferometry can be relaxed by using a single-mode interferometer integrated, thanks to modal filtering. An interferometric instrument integrated L-band would be more than welcome, but needs a technology development effort to develop a method of producing L-band single-mode guides as well as integrated beam combiners. My PhD work was to develop such single mode waveguides as well as beam combiners in order to ob- tain an extinction ratio of 10−4 in the L-band. The selected material is lithium niobate (LiNbO3), the mid-infrared transparency makes it a perfect candidate. We used two methods to make the guides : proton exchange and Titanium diffusion. This latter allows to guide both TE and TM polarizations. As Lithium Niobate is electro-optic, we also worked to internally control the phase delay between channels without mobile mechanical part, applying an electric field at the guide via electrodes "on chip". The electro-optical effect allows us to not only vary the optical path delay between channels but also to settle the photometric balance, paving the way towards the realization of an integrated complete interferometer, lightweight, compact and robust. I therefore sought to characterize and optimize the electro-optical efficiency of the system to obtain a command voltage lower than 15V. The result is a "Y" interferometer presenting two Mach-Zehnders as input for photometric adjustment and offering an extinction ratio of 33dB in monochromatic light (3.39μm). Because the electro-optical drive is very fast (> MHz), it becomes possible to compensate for the phase perturbations induced by the atmosphere (1kHz) in real time. We have worked to build a demonstrator which compensates phase delays of the order of kHz without mechanical mobile part and which guarantees, at 3.39μm, an optical path delay around 3nm. We also realized directional couplers whose coupling ratio can be adjusted via a control voltage. The direct application of this technology is an interferometric component 2TABCD or 3TAC whose defects (unbalanced couplers) can be electrically corrected by calibration
Chastanet, Daniel. "Nouvelles sources compactes dans le moyen-infrarouge : Lasers à cascade quantique au-delà de 16 microns et LED électroluminescentes en régime de couplage fort". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS143/document.
Pełny tekst źródłaThe far infrared (16 µm < λ < 30 µm) is an important area for applications such as detecting wide organic molecules (whose absorption fingerprints falls in this wavelength range) and for radio-astronomy (local oscillator for the heterodyne detection). Unfortunately, the atmospheric transparency window, commonly called the 4th transparency window is almost unexplored.QCL are coherent light sources, covering a range from infrared to THz, based on the engineering of band structures of semiconductors. They have excellent performances in the mid infrared but their effectiveness diminishes in the 4th window and beyond.One aim of this thesis is the development of a new generation of QCL able to cover this spectral region with good performance in terms of output power and maximum operating temperature. A key point in this context is the use of a new material system for these wavelengths: InAs / AlSb. The advantage of this solution is its very small effective mass : 0.023 m0 (compared to 0.043 m0 in the InGaAs wells), which provides a higher gain, resulting in significant performances improvement.Another fundamentally different approach lies in the strong coupling regime. Using an ultra-fast characteristic time associated with Rabi oscillations, can allow the realization of emitting sources with improved quantum efficiency (compared to an bare inter-subband transition). pseudo particles arising from the strong coupling regime in the inter-subband transitions (called polaritons inter-sub-bands) may under certain limits behave as bosons. One then sees the possibility of coherent sources based on the relaxation of a polariton condensate
Ghosh, Amar Nath. "Design, simulations et expériences de génération de supercontinuum dans l'infrarouge moyen dans des fibres à cristaux phoniques en verre souple". Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCD035.
Pełny tekst źródłaThis doctoral thesis, funded within the framework of a European Marie-Curie H2020 SUPUVIR project, focuses on the design and fabrication of new photonic crystal fibers from infrared soft glasses making it possible to produce a wide emission spectrum in the mid-infrared (IR) wavelength region through generation of supercontinuum (SC). Applications of mid-IR SC sources cover infrared spectroscopy, optical detection of chemical and molecular species, materials processing, and biomedical imaging. An alternative to conventional thermal light sources, mid-IR sources have broad spectral bandwidth like a lamp or Globar and high brightness, which is more than 20 times of the sun focussed in a small spot similar to a laser. Several optical fibers with different photonic structures and different soft glasses have been produced and studied. In collaboration with the Institute of Electronic Materials Technology in Warsaw, heavy metal-oxide glass (PBG81) microstructured fibers were first developed and with these fibers we demonstrated the efficient generation of SC from 0.89 to 2.5 µm, limited by the absorption of the glass. Then, in partnership with the University of Rennes and the Technical University of Denmark, we fabricated microstructured fibers based on chalcogenide glasses (As38Se62) with polarization-maintaining property. These fibers have made it possible to generate a linearly polarized 3.1 to 6 µm supercontinuum. SC bandwidth was further extended between 1 µm and 7.4 µm in taper fibers produced from Ge10As22Se68 glass. The laser power handling capacities of these chalcogenide fibers were also analyzed. Finally, we have developed a compact mid-IR SC system using a fiber cascade comprising of silica, fluoride, and chalcogenide fiber, pumped by a fiber laser at 1.55 µm, and making it possible to extend the emission range from 2 to 10 µm. This research work thus constitutes an important step towards the development of stable and compact fiber SC sources for various applications in the mid-infrared
Moreau, Virginie. "Etude du confinement optique dans les lasers à cascade quantique et applications à la détection". Phd thesis, Université Paris Sud - Paris XI, 2008. http://tel.archives-ouvertes.fr/tel-00350075.
Pełny tekst źródłaCe travail de thèse présente l'étude et l'optimisation du confinement optique vertical dans des hétérostructures lasers à cascade quantique épitaxiées sans couche de confinement supérieure. Ces structures sont intéressantes puisqu'elles sont adaptées à la fois au guide à plasmons de surface et au guide avec un confinement par air. En menant une étude approfondie de la répartition du mode optique et du courant électrique, nous avons conçu des structures originales qui ouvrent notamment de nouvelles perspectives sur l'utilisation de ces lasers pour la détection de fluides. Nous avons également montré que l'observation par microscopie en champ proche est un outil précieux pour la caractérisation et la compréhension des lasers à cascade quantique. Finalement, nous posons les bases nécessaires à la réalisation de matrices de lasers monomodes, utilisant la technologie des cristaux photoniques.
Viallon, Maud. "Réalisation et caractérisation de membranes polymères microstructurées capables de moduler leurs propriétés de réflexion dans le domaine du moyen infrarouge : application aux textiles pour le confort thermique". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10105.
Pełny tekst źródłaThe goal of this thesis is the manufacturing of polymer membranes that can be complexed to a textile to improve the thermal comfort felt. They must be able to dynamically modulate their optical properties in the mid-infrared (MIR) according to the environmental conditions.The first part of this work presents the theoretical notions related to thermal comfort and both physical mechanisms hydric and thermal transfers through the textile membranes. A state of the art makes it possible to identify the existing technologies. The concept of photonic crystals and their application in the field of infrared medium are presented. This part ends with the establishment of specifications for the design of a structured polymer membrane using the principle of photonic crystals to modulate the interaction of human thermal radiation.The second part of this work describes the method of finite differences in time domain simulation (FDTD) used to predict the optical properties of micro-structured membranes as function of their geometric characteristics. A first realization in polycrystalline silicon authorizes the validation of the numerical model calibration as well as the protocol of the infrared characterization. The manufacturing process uses cleanroom technologies from microelectronics and microsystems.The last part of this work is devoted to the study by FDTD of microstructured polymer membranes from the previously calibrated 'in-silico' model. This study makes it possible to define geometrical parameters able to modulate the reflection of the infrared having a wavelength between 5 and 15 microns. A manufacturing process is developed which makes it possible to realize self-supporting structured membranes to the appropriate dimensions
Gilles, Clément. "Optique intégrée pour sources largement accordables moyen-infrarouge". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS009/document.
Pełny tekst źródłaIn the mid-infrared, arrays of distributed feedback quantum cascade lasers have been developed as a serious alternative to obtain extended wavelength operation range of laser-based gas sensing systems. Narrow-linewidth, single mode operation and wide tunability are then gathered together on a single chip with high compactness and intrinsic stability. In order to benefit from this extended wavelength range in a single output beam, the key challenge resides in the combination of different technologies to merge the output of different sources via the use of mid-IR photonic integrated circuits (PIC). The PIC can be split into three main blocks: the passive waveguide platform, the beam combiner and the active/passive coupler. For beam handling and guiding, we report fabrication and characterization of deeply etched InP/InGaAs/InP waveguides with state of the art performances. We fabricate and characterize multiplexers based on echelle and arrayed waveguide gratings on InP and SiGe platforms. A 60-to-1 spectral multiplexer operating in the 7-to-8.5 µm range is demonstrated. An advanced multiplexing scheme using interleaved and cross-order operations is also exposed. Finally, we realize quantum cascade laser arrays on InP and silicon. We design, fabricate and characterize an adiabatic coupler to efficiently and monolithically integrate active and passive waveguides. Heterogenous and hybrid integration are also considered with the demonstration of a tunable source using laser array and InP-based multiplexer
Carletti, Luca. "Photonique intégrée nonlinéaire sur plate-formes CMOS compatibles pour applications du proche au moyen infrarouge". Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0013/document.
Pełny tekst źródłaIntegrated photonics offers a vast choice of nonlinear optical phenomena that could potentially be used for realizing chip-based and cost-effective all-optical signal processing devices that can handle, in principle, optical data signals at very high bit rates. The new components and technological solutions arising from this approach could have a considerable impact for telecom and datacom applications. Nonlinear optical effects (such as the optical Kerr effect or the Raman effect) can be potentially used for realizing active devices (e.g. optical amplifiers, modulators, lasers, signal regenerators and wavelength converters). During the last decade, the silicon on insulator (SOI) platform has known a significant development by exploiting the strong optical confinement, offered by this material platform, which is key for the miniaturization and realization of integrated optical devices (such as passive filters, splitters, junctions and multiplexers). However, the presence of strong nonlinear losses in the standard telecom band (around 1.55 µm) prevents some applications where a strong nonlinear optical response is needed and has motivated the research of more suitable material platforms. The primary goal of this thesis was the study of material alternatives to crystalline silicon (for instance hydrogenated amorphous silicon) with very low nonlinear losses and compatible with the CMOS process in order to realize integrated photonics devices based on nonlinear optical phenomena. Alternatively, the use of longer wavelengths (in the mid-IR) relaxes the constraints on the choice of the material platform, through taking advantage of lower nonlinear losses, for instance on the SiGe platform, which is also explored in this thesis. This work is organized as follows. In the first chapter we provide an overview of the nonlinear optical effects used to realize all optical signal processing functions, focusing on the key parameters that are essential (optical confinement and dispersion engineering) for integrated optical components, and presenting the main models used in this thesis. This chapter also includes a review of the main demonstrations reported on crystalline silicon, to give some benchmarks. Chapter 2 introduces the use of photonic crystals as integrated optical structures that can significantly enhance nonlinear optical phenomena. First we present photonic crystal cavities, with a demonstration of second and third harmonic generation that makes use of an original design. In the second part of the chapter, we describe the main features and challenges associated with photonic crystal waveguides in the slow light regime, which will be used later in chapter 4. In chapter 3, we report the experimental results related to the characterization of the optical nonlinear response of integrated waveguides made of two materials that are alternative to crystalline silicon : the hydrogenated amorphous silicon, probed in the near infrared, and the silicon germanium, probed in the mid-infrared. The model presented in chapter 1 is extensively used here for extracting the nonlinear parameters of these materials and it is also extended to account for higher order nonlinearities in the case of silicon germanium tested at longer wavelengths. This chapter also includes a comparison of the nonlinear properties of these two material platforms with respect to the standard SOI. In chapter 4, we combine the use of a material platform that is better suited than SOI for nonlinear applications with integrated photonics structures that are more advanced that those used in chapter 3. Here we describe the design of (slow) modes in photonic crystal waveguides made in hydrogenated amorphous silicon fully embedded in silica. [...]
Didier, Pierre. "Novel mid-infrared quantum cascade devices for applications in free-space optics, data security and microwave photonics". Electronic Thesis or Diss., Institut polytechnique de Paris, 2023. http://www.theses.fr/2023IPPAT029.
Pełny tekst źródłaThis doctoral thesis focuses on free-space optical (FSO) transmission in the mid-infrared region covering three main aspects: high-speed FSO transmission, private communication through chaotic synchronization, and integration of FSO-to-RF communication systems. In the field of high-speed FSO transmission, the research optimizes modulation schemes, equlaization for high speed data transmission in the mid-infrared spectrum. Cascade devices such as interband cascade lasers (ICLs) and quantum cascade lasers (QCLs) are utilized. Data rates of up to 14 Gbps are achieved using ICL and interband cascade interband photodetectors (ICIPs). QCLs and external modulators based on electrically modulated absorption are also implemented, achieving data rates up to 68 Gbps. These devices high modulated power, making them suitable for long-distance transmissions. The thesis also explores the application of chaos synchronization techniques for private communication over FSO links. Chaotic properties of light sources in the mid-infrared are leveraged, enabling the concealment of messages within chaotic signals. The complexity of the generated chaos allows for private transmission, with legitimate users achieving low error rates while non-legitimate users experience a higher error rate. Furthermore, the thesis investigates the integration of FSO and RF communication systems. The aim is to create a conversion between high-speed FSO links and RF links. Heterodyne beating techniques are utilized, combining quantum cascade lasers to generate beat signals. This approach enables the transmission of FSO signals over the Ka band through a QWIP detector. The research demonstrates the feasibility of FSO-to-RF integration, opening possibilities for combining the advantages of both communication systems. Overall, this thesis presents advancements in high-speed FSO transmission, secure communication using chaotic synchronization, and integration of FSO and RF systems. The research findings have implications for various fields, including telecommunications, satellite communication, and secure data transmission
Favreau, Julien. "Étude et développement d'une plateforme photonique moyen infrarouge sur silicium : vers des capteurs intégrés". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS263/document.
Pełny tekst źródłaNowadays, microelectronic chips and sensors are not simply electronic circuits anymore. They are able to convey both electric and optical signal. As shown by the so-called photonic chips used to transmit data at high speed rate. However, this technology only exploits a very small part of the light spectrum, namely in the near infrared. Exploitation of the whole mid-infrared domain (λ=2-20 µm) would allow to develop new integrated sensors using molecules specific spectral fingerprints in this part of the electromagnetic spectrum.This thesis deals with the development of integrated optical circuits on silicon capable of handling these wavelengths and compatible with 200 mm clean room fabrication processes. The technology developed in this work, is based on Si₀,₆Ge₀,₄ channel square waveguides in order to obtain compact and low loss optical circuits. First of all, the design of optical functions required to build circuits is presented. Then, these functions are assembled into circuits which are manufactured and characterized in order to assess performances of the developed technology. Two circuits have been produced: one with standard processes and one with damascene processes. The first one has the advantage of using known processes, whereas the second one allows to make waveguides for different wavelengths on a single chip. These two circuits have been characterized in order to conduct a comparative study between the two fabrication processes. Finally, in order to mature the technology, an in-depth study on grating coupler for Si₀,₆Ge₀,₄ waveguides have been conducted. It has led to the manufacturing and characterization of two grating couplers : one made of air inclusions and another locally suspended
Ari, Julien. "Développement de verres spéciaux adaptés à la photonique moyen infrarouge pour des applications détection et mesure de gaz". Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S151/document.
Pełny tekst źródłaGlobal warming due to the increase of greenhouse gas emissions is one of the main current challenges. In this context, the CO2 storage in geological reservoirs appears as a likely way to limit the consequences of these emissions on the environment. For safety reasons, this management method requires continuous monitoring of the storage tanks by using IR sensors who can go down into the wells. The application of this technology also requires to know the CO2 behavior during various storage steps, in particular when it is in its supercritical state. This is why microfluidics is currently used to simulate and understand the phenomena related to the injection and storage of CO2 in supercritical form. The implementation of such approach requires: (i) the development of novel compact solutions for in situ continuous gas monitoring to secure the storage site and; (ii) a better understanding of the CO2 behavior during the different storage steps.The first research axis of this thesis has consisted in developing vitreous active materials to increase the efficiency of optical CO2 sensor (and eventually other gas like CH4 or CO) for their continuous monitoring in saline aquifer storage sites. This sensor must be able to be deployed in depth and be sensitive to CO2 concentrations below 1000 ppmv to quickly identify any leak. Chalcogenide glasses doped with specific rare earth ions may provide broadband luminescence that can be used to detect infrared signatures of all molecules whose absorption bands are located in the 3-5 µm spectral region. Glass compositions Ga5Ge20Sb10(Se,S)65 (mol.%) doped Pr3+ and Dy3+ have been developed in order to be integrated into a functional environmental CO2 sensor. The multi-sensing gas (CO2, CH4 and CO) potential of these materials has also been investigated.Current HP/HT microfluidic systems do not allow coupling FTIR and Raman spectroscopies. This problem is due to the using of Pyrex glass for the manufacture of these microreactors. That is why the second research axis developed during this thesis has consisted in exploring various vitreous systems to propose an alternative to the Pyrex glass. The target glass had to demonstrate the best compromise between the desired optical, thermomechanical and electrical properties. In this way, glasses based on GeO2 have been developed to meet these specifications, such as the anodic bonding process used to attach the glass on the silicon wafer. The glass composition selected after the completed studies is 70GeO2-15Al2O3-10La2O3-5Na2O (mol.%)
Renard, Charles. "Hétérostructures Antimoniures/Arséniures pour les applications optoélectroniques dans le moyen infrarouge". Phd thesis, Université Paris-Diderot - Paris VII, 2005. http://tel.archives-ouvertes.fr/tel-00124336.
Pełny tekst źródłaL'objet de cette thèse a consisté, dans un premier temps, à déterminer les conditions de croissance permettant la réalisation des lasers à cascade quantique basés sur le système de matériaux AlAsSb/GaInAs épitaxié sur substrat d'InP et de détecteurs photovoltaïques InAsSb épitaxiés sur substrat de GaSb. Pour ce faire, l'ensemble des paramètres intervenant dans l'incorporation concurrentielle des deux éléments V As et Sb (température, vitesse, nature de l'élément III...) a été étudié. Une procédure de détermination des épaisseurs individuelles et des compositions des hétérostructures GaInAs/AlAsSb, par diffraction de rayons X, basée sur l'utilisation d'un double superréseau a également été proposée. Ce travail a permis de mieux comprendre les phénomènes intervenant aux interfaces selon les conditions de croissance utilisées et d'obtenir ainsi un calibrage rigoureux et reproductible. Des résultats préliminaires satisfaisants ont finalement été obtenus sur les diodes électroluminescentes AlAsSb/GaInAs à cascade quantique sur InP ainsi que sur les détecteurs photovoltaïques InAsSb sur GaSb.
La seconde partie de cette thèse a consisté en l'optimisation des conditions de croissance des hétérostructures (Al,Ga)Sb/InAs épitaxiées sur substrat d'InAs et de GaSb. Dans ce système de matériaux, l'existence d'une ségrégation d'indium aux interfaces AlSb/InAs a pu être mise en évidence par différentes techniques de caractérisation (HRTEM, RHEED, HRXRD). La prise en compte de cette ségrégation a permis d'améliorer les performances des LCQs InAs/AlSb et d'atteindre le fonctionnement à température ambiante. Des résultats prometteurs ont également été obtenus pour des structures détectrices interbandes à cascade GaSb/AlSb/InAs.
Duhant, Mathieu. "Etude des sources supercontinuum à fibres transparentes dans le moyen infrarouge". Phd thesis, Université de Bourgogne, 2012. http://tel.archives-ouvertes.fr/tel-00833949.
Pełny tekst źródłaBenveniste, Elsa. "Etude du gain des lasers à cascade quantique dans le moyen infrarouge". Paris 7, 2009. http://www.theses.fr/2009PA077215.
Pełny tekst źródłaQuantum cascade lasers (QCL) have experienced a constant development since their invention in 1994 and represent so far the most interesting compact source for optical Systems operating in the mid-infrared and in the THz region of the spectrum. In order to respond to applications4s requirements, it is important to study the key physical parameters of the gain in QCL. In the first part of this work, we studied the impact on the gain of the material properties, such as the electron effective mass. In the second part of this work, we realized a new experimental technique for an accurate measurement of the gain, as a function of the voltage applied to the device. Thanks to this technique, we studied several parameters, which have an influence on the laser's performances, such as losses, transparency current, electronic and lattice temperature. Our experimental results were also used to estimate the population inversion on the laser transition and showed the possibility of probing the population of the QCL's electronic states as a function of the bias and the time
Ducros, Nicolas. "Génération de supercontinuum dans le moyen infrarouge à l'aide de fibres optiques". Limoges, 2010. https://aurore.unilim.fr/theses/nxfile/default/1ff43c99-e824-4b15-b1cb-5e40b4405d47/blobholder:0/2010LIMO4040.pdf.
Pełny tekst źródłaThe goal of this PhD thesis is the study and the development of fibre based supercontinuum systems emitting in the mid-infrared. The physical origins of supercontinuum generation are developped in the first part of this work. Then, supercontinuum generation based on a heavy metal oxyde glass fibre is studied. Two pump sources have been tested yielding broad bandwidth radiation from at least 1 µm up to 2. 8 µm. Numerical computations have been carried out showing that the limitation of the supercontinuum generated can be attributed to the strong O-H- absorption band at 2. 8 µm. Finally, high average power supercontinuum generation has been demonstrated in a large mode area fluoride step-index fibre. The average power was 100 mW over the whole spectrum extending from 1 µm up to 4. 2 µm. Numerical computations were used to simplify the pump source architecture
Van, de walle Aymeric. "Source paramétrique dans l'infrarouge moyen à haute cadence". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLO009/document.
Pełny tekst źródłaThis 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
BERTIN, CHANTAL. "Caracterisation de la degradation microbienne de constituants parietaux par spectroscopie dans l'infrarouge proche et moyen". Nantes, 1989. http://www.theses.fr/1989NANT2041.
Pełny tekst źródłaMondelain, Didier. "Lidar linéaire et non linéaire dans l'infrarouge moyen". Phd thesis, Université Claude Bernard - Lyon I, 2001. http://tel.archives-ouvertes.fr/tel-00396346.
Pełny tekst źródłaUne méthode originale, à une longueur d'onde, a été développée. Elle est basée sur l'impaction et l'étude de filtres permettant d'obtenir des informations complémentaires sur la distribution de taille des aérosols et sur leur composition. Les résultats, obtenus dans l'UV montrent que la distribution a un mode pour les petites tailles (~100 nm) et un mode pour les particules plus grosses (~1 μm). Notre lidar a aussi permis de mesurer la concentration en aérosols, l'évolution et la stratification de la couche limite. Mais cette méthode reste lourde à cause de l'étude des filtres et utilise comme hypothèse forte que l'atmosphère est homogène verticalement.
Pour distinguer entre les modes des particules et obtenir un diagnostique « tout-optique », nous avons étendu dans l'IR, plus sensible aux aérosols de la taille du micron, le système lidar UV existant, plus sensible aux petites tailles.
Cette extension est basée sur des oscillateurs paramétriques optiques (OPO). Les différents cristaux susceptibles de produire efficacement de l'IR moyen ont été testés. Ces cristaux sont le KTiOPO4, le KTiAsO4 et le KNbO3. Puis, un de ces OPO a été implanté dans notre système lidar. Les mesures lidar préliminaires de concentration dans l'IR, ont été obtenues pour des gouttelettes d'eau lors d'un épisode de brume. Parallèlement aux systèmes lidar linéaires précédents, un projet de lidar non-linéaire (projet Teramobile), a vu le jour. Une source de lumière blanche provenant des filaments, générés dans l'air lors de la propagation d'un faisceau laser térawatt, est utilisée pour faire du lidar aérosols multispectral. Avec cette source allant de l'UV à l'IR moyen, des mesures de concentration en aérosols seront possibles sans aucune hypothèse a priori contrairement aux méthodes précédentes.
Duval, Simon. "Laser femtoseconde à fibre optique émettant dans l'infrarouge moyen". Doctoral thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/37364.
Pełny tekst źródłaThe development of lasers emitting in the mid-infrared, a spectral region where the funda-mental resonances of several molecules are found, is one of the most promising avenues in laserscience. However, the democratization of these coherent light sources is required for enablingbreakthrough applications in healthcare, environment, industry and research. Thanks to theirsimplicity, robustness, reliability and their unequaled optical performances, fiber lasers are thecandidates of choice for enabling this technological shift toward the mid-infrared.In this project, the first femtosecond fiber laser emitting in the mid-infrared was realized. Thishigh added-value laser offers exceptionnal temporal, spectral and spatial properties that pavethe way for several applications in spectroscopy and laser-matter interaction.The design, optimization and theoretical study of this femtosecond laser cavity emitting at 2.8μm are presented in chapters 1 and 2 as well as in appendix B. The generation of ultrashortpulses in this laser relies on a mode-locking technique based on nonlinear polarization evolutionof the signal propagating inside an erbium-doped fluoride fiber. Pulses with durations below300 fs and estimated peak powers above 20 kW were directly generated from this oscillator.The second part of this thesis (chapters 3 and 4) presents the design and numerical studyof an external fiber amplifier that significantly improves the performances of the oscillator.This amplifier that uses only one segment of erbium-doped fluorozirconate fiber enables thegeneration of ultrashort pulses with peak powers above 200 kW. Due to the soliton self-frequency shift process occuring inside the amplifier, the central wavelength of the outputpulses can be tuned from 2.8 to 3.6μm. This tunable femtosecond system in the mid-infraredcan be further simplified and improved and can also be adapted to other novel laser transitionsin the mid-infrared. This work paves the way for new applications to emerge both in thescientific and the industrial worlds.
Lene, Mirouze Frédéric De. "Analyse quantitative en spectrométrie moyen infrarouge par transformée de Fourier : perspectives d'application dans le domaine agro-alimentaire". Lille 1, 1992. http://www.theses.fr/1992LIL10015.
Pełny tekst źródłaLe, Camus Arthur. "Conception et élaboration de composants photoniques pour l'infrarouge moyen inscrits par impulsions ultra brèves". Doctoral thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/66425.
Pełny tekst źródłaL’infrarouge moyen présente un grand intérêt pour de nombreuses applications dans des domaines variés comme la médecine, la biologie, l’environnement ou encore l’astronomie. Il y a donc un besoin de sources et de dispositifs fonctionnant dans cette bande de longueur d’onde s’étendant approximativement de 2 à 20 µm. L’élaboration de ces dispositifs passe par le développement de matériaux transparents dans l’infrarouge moyen puis par la fonctionnalisation optique de ces matériaux. Dans le cadre de cette thèse de doctorat, nous nous proposons d’étudier la fabrication de composants dans un verre d’oxyde de métaux lourds (baryum, gallium, germanium : BGG), dont l’intérêt est la combinaison d’une bonne transmission jusque dans l’IR moyen (de ~350 nm à ~5 µm) et de bonnes résistances mécanique et chimique. La technique utilisée pour la fonctionnalisation optique de ce verre est l’inscription directe par impulsions ultra courtes. Cette dernière permet de modifier localement – et de manière permanente – un matériau par la focalisation d’impulsions d’une durée de l’ordre de quelques dizaines ou centaines de femto secondes, générant des intensités lumineuses très importantes et permettant l’absorption non-linéaire d’une partie de l’énergie du faisceau laser. Le caractère non linéaire de l’interaction permet l’inscription de structures tridimensionnelles dans le volume du matériau. Grâce à cette technique, on peut notamment fabriquer des guides d’onde, des canaux de microfluidique et des motifs fluorescents pour ne citer que quelques exemples. Nous rapportons dans cette thèse une étude détaillée de l’inscription par laser femtoseconde dans différents types de verres BGG. Nous montrons qu’il est possible d’avoir un changement d’indice positif élevé, permettant la formation de composants à base de guides d’onde pour l’IR moyen. En particulier, nous présentons des résultats de mesures sur des guides d’onde et des coupleurs dans l’IR moyen, inscrits dans un verre BGG et dans la silice. Un autre type verre, dérivé des BGG et dopé en ions argents, est également étudié dans le cadre de l’inscription par laser femtoseconde. Comme il a été observé dans d’autres types de verres d’oxydes, les ions argent modifient l’interaction laser matière et apportent des propriétés spécifiques à l’argent : fluorescence, génération de seconde harmonique et résonance de plasmons de surface.
The mid-infrared region is of great interest for many applications in various fields such as medicine, biology, environment and astronomy. Therefore, there is a need for developing sources and devices operating in this wavelength region, spanning approximately from 2 to20 µm. The development of these devices involves the development of mid-IR transparent materials and then the optical functionalization of these materials. In the framework of this PhD thesis, we propose to study the fabrication of components in glass of heavy metaloxides (barium, gallium, germanium: BGG), whose interest is the combination of a good transmission (from ~350 nm to ~5 µm) and good mechanical and chemical resistances. The technique used for the optical functionalization of this glass is direct inscription by ultra-short pulses. This technique allows a local and permanent modification of a material by focusing pulses of a duration of a few tens or hundreds of femtoseconds, generating very high light intensities and allowing the non-linear absorption of the laser beam energy. The non-linear nature of the interaction allows the inscription of three-dimensional structures in the bulk. Thanks to this technique, we can produce waveguides, microfluidic channels and fluorescent patterns, to name but a few examples. In this thesis, we report a detailed study of femtosecond laser inscription in different types of BGG glasses. We show that it is possible to have a high positive index change, allowing the formation of waveguide-based components for mid-IR. In particular, we present measurements results on waveguides and couplers in the mid-IR, embedded in BGG glass and fused silica. Another type of glass derived from BGG and doped with silver ions is also studied with the femtosecond laser inscription. As observed in other types of oxide glasses, silver ions modify the laser-matter interaction and provide silver-specific properties such as fluorescence, second harmonic generation and surface plasmons resonance.
Allioux, David. "Etude de micro-disques de carbure de silicium sur substrat de silicium, vers une application d’optique non-linéaire intégrée du proche au moyen infrarouge". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI049/document.
Pełny tekst źródłaThis Ph.D. thesis studies the design, fabrication and characterization of silicon carbide micro-disks on top of silicon designed to operate from the near to the mid-IR. We study a simple but efficient approach leading to the suppression of higher order whispering gallery modes while preserving the fundamental mode's quality factor. This suppression, typically useful for frequency comb generation is simply based of the silicon pillar under etching and can be easily transferred to other material platforms and wavelengths. The first chapter is a general introduction of whispering gallery mode micro-resonator in which we describe the extremely complex and diverse physics of these structures. The second chapter is focused on SiC micro-disks themselves. We begin with a general introduction of the material to continue by simulating light propagation inside these resonators to be able to design innovative structures. Using the higher optical refractive index of silicon compared to the one of silicon carbide, we demonstrate that it is possible to suppress higher radial modes. We then briefly describe the fabrication processes. The third chapter gather the experimental studies lead on the micro-disks. First characterizations by evanescent coupling in the near infrared enable us to identify the whispering gallery modes inside the resonator. Characterization on micro-disks with smaller under-etching then enables us to demonstrate the higher suppression. We finally lead a thermo-optic study of the material to validate its compatibility to high power and high temperature regimes in which SiC stand out from other integrated optics materials. Finally, the last chapter is dedicated to non-linear optics and mid-infrared perspectives. We propose a dispersion study that, we hope, should enable the generation of Kerr frequency combs sources in a near future
Frayssinous, Clément. "Étude du traitement des polymères par des sources lasers fibrées émettant dans l'infrarouge moyen". Doctoral thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/66860.
Pełny tekst źródłaThibault-Maheu, Olivier. "Génération de supercontinuum en régime femtoseconde dans l'infrarouge moyen dans des fibres optiques". Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/25817.
Pełny tekst źródłaSupercontinuum generation is an extreme spectral broadening that takes place in a dispersive and nonlinear medium like an optical fiber. It has found applications in various fields such as spectroscopy, metrology and defense and security. Some of them require light with a broad spectrum covering the atmospheric transmission window between 3 and 5 μm. However, currently used fibers like silica and ZBLAN have limited transmission in this range, thus justifying the use of new materials. We propose the use of fluoroindate and arsenic trisulfide fibers to serve this purpose. Both of these materials have been drawn in fibers with very low transmission losses over this spectral range. In this work, we used femtosecond pulses to generate supercontinuum in fluoroindate and arsenic trisulfide fibers. We demontrated a very broad supercontinuum in the fluoroindate fiber using femtosecond pulses in the anomalous dispersion regime of the fiber at 2.5 μm. The results were not that promising in chalcogenide fibers because of large normal dispersion at the wavelength used and low damage threshold.
Gallot, Guilhem. "Génération d'impulsions femtoseconde intenses et accordables dans l'infrarouge moyen dynamique de la liaison hydrogène dans l'eau liquide". Palaiseau, Ecole polytechnique, 1998. http://www.theses.fr/1998EPXX0024.
Pełny tekst źródłaChevallier, Christ-Yves. "Conception de miroirs à réseau sub-longueur d'onde pour application VCSEL dans le moyen infrarouge". Phd thesis, Supélec, 2013. http://tel.archives-ouvertes.fr/tel-01024257.
Pełny tekst źródłaLaaroussi, Youness. "Nouvelles approches technologiques pour la fabrication de Lasers à émission verticale dans le moyen infrarouge". Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00781795.
Pełny tekst źródłaMennerat, Gabriel. "Conception, modélisation et réalisation d'une source cohérente de forte énergie accordable dans le moyen infrarouge". Université Louis Pasteur (Strasbourg) (1971-2008), 2000. http://www.theses.fr/2000STR13245.
Pełny tekst źródłaThis thesis deals with high-energy narrow-linewidth optical frequency conversion in the 2-22 μm spectral range in the nanosecond regime. We have designed and implemented a frequency-conversion system involving a 10 Hz 1. 06 μm-pumped optical parametric oscillator (OPO) from which the signal and idler output waves are down converted in a second nonlinear optical stage. The OPO consists of a lithium niobate (LiNbO3) or a KTP (KTiOPO4) nonlinear crystal located within a singly-resonant cavity with additional frequency selective components. This OPO produces two waves in the 1. 8-2. 6 μm range with pulse energies up to 500 mJ near 2 μm in a broad bandwidth configuration and energies between 100 and 350 mJ with the line narrowing elements (linewidth from 5 to 30 GHz). The signal and idler waves from the OPO have been converted by difference-frequency mixing in various semiconductor crystals including cadmium selenide (CdSe), gallium selenide (GaSe), TAS (TL3AsSe3) and silver selenogallate (AgGaSe2). Output energies from 2 up to 10 mJ at wavelengths between 22 and 10 μm were obtained in the nonlinear crystal CdSe. We achieved a continuous tunability from 6 to 19. 2 μm in GaSe with energies up to 1. 5 mJ. We also demonstrated the first down-conversion device using the infrared crystal TAS emitting a difference-frequency wave in the μm range. We have developed an inclusive numerical model for broad-bandwidth nanosecond OPO’s taking into account the most relevant physics including diffraction, walkoff, absorption and second-order polarization effects. The model was validated by comprehensive comparison with the energy, spectral, temporal and spatial performances of the two nonlinear optical stages. It was subsequently used as an optimization tool and it demonstrated efficiency limitations due to nonlinear absorption processes in the frequency mixing crystals
Maisons, Grégory. "Réalisation de source lasers monomodes innovantes émettant dans le moyen infrarouge : application à la spectroscopie". Phd thesis, Grenoble, 2010. http://www.theses.fr/2010GRENY058.
Pełny tekst źródłaThis thesis work is focused on the top metal grating applied to the Quantum Cascade Lasers operating in the mid-infrared range of the electromagnetic spectrum. Physic phenomena involved in such structure have been understood thank to simple models which have been powerful tools to design devices. Results are confirmed by numerical studies based on the more complex S-matrix formalism. This study leads to several realizations: (i) The processing of single-mode sources with a precise control of the wavelength. The originality of these devices comes from the low loss interaction of the electromagnetic field with the metal. This configuration enables the processing of room temperature continuous wave distributed feedback (DFB) QCLs. (ii) The development of low divergence new devices, based on the combining of a first-order and a second order grating. (iii) The demonstration of the capability of a QCL optically coupled to a high finesse cavity (OF-CEAS : Optical-Feedback Cavity-Enhanced Absorption Spectroscopy) for the high sensitive molecular spectroscopy. All these developments have demonstrated the high maturity level of the top metallic grating, well adapted to the quantum cascade laser for their integration in spectroscopic systems
Liu, Qiankun. "SiGe photonic integrated circuits for mid-infrared sensing applications". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS166/document.
Pełny tekst źródłaMid-infrared (mid-IR) spectroscopy is a nearly universal way to identify chemical and biological substances, as most of the molecules have their vibrational and rotational resonances in the mid-IR wavelength range. Commercially available mid-IR systems are based on bulky and expensive equipment, while lots of efforts are now devoted to the reduction of their size down to chip-scale dimensions. The use of silicon photonics for the demonstration of mid-IR photonic circuits will benefit from reliable and high-volume fabrication to offer high performance, low cost, compact, lightweight and power consumption photonic circuits, which is particularly interesting for mid-IR spectroscopic sensing systems that need to be portable and low cost. Among the different materials available in silicon photonics, Germanium (Ge) and Silicon-Germanium (SiGe) alloys with a high Ge concentration are particularly interesting because of the wide transparency window of Ge up to 15 µm. In this context, the objective of this thesis is to investigate a new Ge-rich graded SiGe platform for mid-IR photonic circuits. Such new plateform was expected to benefit from a wide transparency wavelength range and a high versatility in terms of optical engineering (effective index, dispersion, …). During this thesis, different waveguides platforms based on different graded profiles have been investigated. First it has been shown that waveguides with low optical losses of less than 3 dB/cm can be obtained in a wide wavelength range, from 5.5 to 8.5 µm. A proof of concept of sensing based on the absorption of the evanescent component of the optical mode has then been demonstrated. Finally, elementary building blocs have been investigated. The first Bragg mirror-based Fabry Perot cavities and racetrack resonators have been demonstrated around 8 µm wavelength. A broadband dual-polarization MIR integrated spatial heterodyne Fourier-Transform spectrometer has also been obtained. All these results rely on material and device design, clean-room fabrication and experimental characterization. This work was done in the Framework of EU project INsPIRE in collaboration with Pr. Giovanni Isella from Politecnico Di Milano
Robichaud, Louis-Rafaël, i Louis-Rafaël Robichaud. "Génération de supercontinuum dans l'infrarouge moyen à partir de fibres optiques à saut d'indice". Master's thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/38229.
Pełny tekst źródłaCe mémoire porte sur la génération de supercontinuum (SC) dans l’infrarouge moyen (mid-IR) à partir de fibres optiques à saut d’indice en vue d’aider l’innovation de la prochaine génération de systèmes lasers spectroscopiques autant en télédétection qu’en microscopie. Une revue exhaustive de littérature ainsi qu’une explication des bases théoriques de la génération de SC mid-IR sont présentées. Deux résultats d’impact ont été obtenus au cours des travaux. D’abord, le premier SC de type cascade s’étalant jusqu’à 8 μm a été démontré, et ce via une fibre optique d’AsSe monomode par un pompage d’impulsions picosecondes amplifiées. Ensuite, le premier SC atteignant une puissance moyenne de l’ordre du watt a été démontrée dans une fibre d’AsSe/AsS. Ce dernier résultat a été possible grâce au développement d’un laser à fibre ultrarapide amplifié émettant des impulsions hautement énergétiques à 3.6 μm et, aussi, à la déposition d’une couche mince antireflet d’Al2O3.
This thesis focuses on the generation of supercontinuum (SC) in the mid-infrared (mid- IR) from step-index optical fiber in order to help the next generation of spectroscopic laser systems in both remote sensing and micro-spectroscopy applications. A comprehensive review of the literature as well as an explanation of the theoretical basis of mid-IR SC generation is presented. Two impact results were obtained during the master. First, the first cascaded SC up to 8 μm was demonstrated via a single-mode AsSe optical fiber by pumping with amplified picosecond pulses. Then, the first SC reaching an average power in the watt-level was demonstrated in an AsSe fiber, thanks to the amplified femtosecond fiber laser emitting high energy pulses at 3.6 μm and the deposition of a Al2O3 anti-reflection coatings.
This thesis focuses on the generation of supercontinuum (SC) in the mid-infrared (mid- IR) from step-index optical fiber in order to help the next generation of spectroscopic laser systems in both remote sensing and micro-spectroscopy applications. A comprehensive review of the literature as well as an explanation of the theoretical basis of mid-IR SC generation is presented. Two impact results were obtained during the master. First, the first cascaded SC up to 8 μm was demonstrated via a single-mode AsSe optical fiber by pumping with amplified picosecond pulses. Then, the first SC reaching an average power in the watt-level was demonstrated in an AsSe fiber, thanks to the amplified femtosecond fiber laser emitting high energy pulses at 3.6 μm and the deposition of a Al2O3 anti-reflection coatings.
Moumdji, Souad. "Lasers à cristaux photoniques pour la spectroscopie infrarouge". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2011. http://tel.archives-ouvertes.fr/tel-01068165.
Pełny tekst źródłaJouy, Pierre. "Dispositifs quantiques en régime de couplage ultra-fort lumière-matière pour l'optoélectronique dans le moyen infrarouge". Phd thesis, Université Paris-Diderot - Paris VII, 2012. http://tel.archives-ouvertes.fr/tel-00700819.
Pełny tekst źródłaLebedinsky, Jérémy. "Détermination des champs de température et de concentration par spectroscopie dans une combustion". Thesis, Paris 10, 2013. http://www.theses.fr/2013PA100183/document.
Pełny tekst źródłaThe aim of the present PhD thesis was to develop and apply a new measurement technique allowing one to create maps of the temperature and t-he concentration of various species within combustion gas, to determine the performances of the engines and get a better understanding of the reaction mechanisms.In order to do so, a non-invasive optical measurement technique was setup. This has enabled us to have better an analysis of the performances and hence, a faster adjustment of the engines. Thanks to its characteristics, the system is able to do some spatial and temporal resolved measurements. Apart from reacting flows in propellers, this measurement technique can also be used for the design of detonation and spark ignition engines or compression engines. The response times (lower than 10 μs) are compatible with the phenomena under investigation. This technique can also be used in airplanes to enable on-flight measurements.The aim was hence to setup an optical system allowing the measurement of these different parameters from a distance. Spectroscopy is a well-suited tool for this work. It is a non-intrusive physical measurement which, combined with LIDAR, allows the precise and instantaneous measurement of the temperature and the concentration of combustion gas as well as the following of their temporal evolution. It would be worth considering measuring the progress of the combustion directly so as to improve the performance and hence reduce the formation of pollutants
Gerber, Fanny. "Estimation du contenu en eau de la végétation par télédétection hyperspectrale dans le infrarouge". Paris, Institut de physique du globe, 2011. http://www.theses.fr/2011GLOB0006.
Pełny tekst źródłaHassoun, Abdo. "Développement de méthodes rapides et non destructives basées sur les spectroscopies de fluorescence et dans le moyen infrarouge pour la détermination de la qualité du poisson". Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10179.
Pełny tekst źródłaNowadays, consumers are seeking fresh, natural, and authentic products, and they pay close attention to the origin of the products they consume. The spectroscopic methods, especially front-face fluorescence spectroscopy (FFFS) and mid-infrared spectroscopy (MIR), have been widely used to determine the quality of food products. However, their use has not yet been sufficiently developed in the field of fish and seafood products to assess the quality - freshness and authenticity of these products. The first part of this work was dedicated to investigate the potential of FFFS to evaluate the freshness of fish stored under different conditions, compared to the traditional methods. The results obtained with fluorescence spectroscopy allowed discriminating between whiting fillets as a function of the storage time and storage condition. The preservation of whiting fillets under modified atmosphere packaging composed of 50 % CO2 and 50 % N2 and the soaking of mackerel fillets in the essential oils of basil / rosemary have been proposed to extend the shelf life of fish. Furthermore, with the aim of exploiting the potential of spectroscopic methods to authenticate fish, the following studies were undertaken :- Study conducted on fresh and frozen thawed sea bass fillets with the purpose of developing a rapid method based on the FFFS to differentiate between fresh and frozen / thawed fish. - Authentication of tuna loins and canned tuna according to their geographical origins (Indian, Pacific, and Atlantic) and their species (yellowfin, skipjack, and bigeye)
Lambert, Girard Simon. "Détection de molécules par lidar agile multi-longueurs d'onde dans l'infrarouge moyen". Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26425.
Pełny tekst źródłaThis thesis presents the proof-of-concept of a novel remote sensing system designed for the detection of molecular species, such as gas pollutants, via active Differential Optical Absorption Spectroscopy (DOAS) in the short and mid wavelength infrared (SWIR/MWIR). The system is designed to be used in applications where gases need to be detected at a distance of about one hundred meters with the use of non-cooperative targets such as topographical features. The system includes an Optical Parametric Generator (OPG) generating broad linewidth (10 to > 100 nm) pulses tunable between 1.5 and 3.8 µm. A telescope coupled to a grating spectrograph and an in-house gated MCT-APD measures the whole return spectrum of each pulse. Experiments show simultaneous detection in indoor atmospheric air and inside a cell of H2O and CO2 at 2 µm and H2O and CH4 at 3.3 µm. In the context of our experiment, the detection limits for CO2 and CH4 are 158 and 1 ppm·m, respectively. A new algorithm is also presented enabling the determination of concentrations when spectra include strong absorption features. The development of a dedicated Optical Parametric Generator (OPG) is presented in detail. Its use in remote sensing of gaseous pollutants offers some promising advantages. The OPG properties are studied numerically and experimentally in order to optimize its use for the application. We discuss trade-offs to be made on the properties of the pump, crystal and seeding signal in order to optimize the pulse spectral density and divergence while enabling energy scaling. A seed with a large spectral bandwidth is shown to enhance the pulse to pulse stability and optimize the pulse spectral density and divergence. A numerical model simulating the OPG process is proposed and includes the multiple wavelength nature of the beams. It shows excellent agreement with experimental output power. The model also explains the mechanisms of gain saturation in OPGs and helps finding means of enhancing the pulse to pulse stability.
Sanchez, Dorian. "Étude et conception d’un nouveau système de confinement pour le VCSEL GaSb émettant dans le moyen-infrarouge". Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20204/document.
Pełny tekst źródłaThis thesis deals with study and conception of GaSb-based electrically pumped Vertical Cavity Surface Emitting Lasers (EP-VCSELs) emitting in the mid-infrared range above 2 µm. This VCSELs exhibits suitable characteristics for gas analysis like single-mode emission and a large current tunability without mode-hopping. The objective of this work was to develop such devices. The first part of this work is about properties of the epitaxial stack layers used to form the VCSEL structure. The second parts deal with characteristics and the confinement system to design a single mode cavity. The third part presents manufacturing process which has been set up, like Tunnel Junction (TJ) under-etching, which is an innovate approach on the GaSb system. It allows reducing TJ diameter down to 6 µm, which is a necessary point to demonstrate single-mode operation.The final part of this manuscript presents the characterisations purchased on the under-etched TJ monolithic-VCSELs. Selective under-etching of the TJ allowed the first demonstration of the first single-mode monolithic EP-VCSEL. This device emits around 2.3 µm in continuous regime above room temperature. This device exhibits threshold currents as low as 1.9 mA and operate up to 70°C. The development of bipolar cascaded VCSELs has also allowed increasing the optical power on large diameter multimode, with a maximum output power of 300 µW and 950 µW@20°C for the classic and the bipolar cascaded VCSEL respectively
Dherbecourt, Jean-Baptiste. "Processus non linéaires pour la génération d'impulsions picosecondes accordables dans l'infrarouge moyen". Phd thesis, Palaiseau, Ecole polytechnique, 2011. http://pastel.archives-ouvertes.fr/docs/00/59/92/11/PDF/JBthese.pdf.
Pełny tekst źródłaMany applications, like time-resolved spectroscopy, require the development of new coherent light sources emitting tunable short pulses in the mid-infrared. In this field, nonlinear optics offer particularly attractive solutions. First of all, the parametric generation process allows extension of the spectral coverage of conventionnal laser sources. Secondly, nonlinear processes display specific properties, which can be controlled in order to create original fast optical functions. In this work, we use these properties to realize picosecond pulses generation devices. We begin with the realization of a synchronously pumped OPO based on a ZGP crystal, emitting tunable picosecond pulses in the 3,8 µm- 5,6 µm spectral range. The performances of the different conversion stages are discussed from experimental and numerical considerations. Then we adress optical sources including a laser medium and a nonlinear crystal. We build a nonlinear mirror using a PPLN crystal and insert it in a Cr2+:ZnSe laser to produce tunable picosecond pulses by passive modelocking in the 2,45 µm - 2,55 µm range. The nonlinear mirror is designed and characterized in an extracavity experiment, then we detail the mode-locking experiment. Finally, we generalize the nonlinear mirror concept, by proposing means of getting passive mode-locking by combination of amplitude and phase modulation in the laser cavity
Spitz, Olivier. "Mid-infrared quantum cascade lasers for chaos secure communications". Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLT054.
Pełny tekst źródłaThe mid-infrared domain is a promising optical domain because it holds two transparency atmospheric windows, as well as the fingerprint of many chemical compounds. Quantum cascade lasers (QCLs) are one of the available sources in this domain and have already been proven useful for spectroscopic applications and free-space communications. The purpose of that dissertation is to go one step further by implementing a secure free-space communication relying on optical chaos and consequently, to give an accurate cartography of non-linear phenomena in quantum cascade lasers. Initial efforts about free-space secure chaotic transmission have been carried out during this Ph.D. thesis with two chaos-synchronized QCLs, which is a pioneer result paving the way for mid-infrared private communications. In order to have a global picture about the non-linear dynamics in QCLs under external optical feedback, we tuned many experimental parameters and this allowed us studying new phenomena in QCLs. We thus found similarities between QCLs and laser diodes when the chaotic dropouts are synchronized with an external modulation, known as the entrainment phenomenon. A cross-polarization reinjection technique led to square-wave emission in the output of the QCL. Eventually, we studied the triggering of rogue waves in QCLs. Rogue waves are a quite common phenomenon in optics (among other domains in science) but they have never been triggered on-demand in semiconductor lasers under external optical feedback before. Further studies will try to avoid such phenomenon in the output of a QCL under external optical feedback since it can disturb the message to be transmitted in a secure communication. All these experimental results allowed a better understanding of the non-linear dynamics of QCLs and will extend the potential applications of this kind of semiconductor lasers, which have currently been restricted to molecular spectroscopy and optical countermeasure systems
Rodriguez, Jean-Baptiste. "Superréseaux InAs/GaSb réalisés par épitaxie par jets moléculaires pour photodétection à 300 K dans le moyen-infrarouge". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2005. http://tel.archives-ouvertes.fr/tel-00618583.
Pełny tekst źródłaRodriguez, Jean Baptiste. "Superréseaux InAs/GaSb réalisés par épitaxie par jets moléculaires pour photodétection à 300 K dans le moyen-infrarouge". Montpellier 2, 2005. http://www.theses.fr/2005MON20223.
Pełny tekst źródłaDUPONT, EMMANUEL. "Modulation de phase et d'amplitude d'ondes electromagnetiques moyen-infrarouge dans des structures a multi-puits quantiques gaas/gaalas". Paris 11, 1993. http://www.theses.fr/1993PA112018.
Pełny tekst źródłaJahjah, Mohammad. "Mise au point d'un système innovant de spectroscopie d'absorption multigaz par diodes lasers accordables dans le moyen infrarouge". Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20158/document.
Pełny tekst źródłaThe measurement of the pollutants is the subject since the late twentieth century especially in attention to protecting the planet. The gaseous species, specifically methane, present in the MIR, has strengths rays very intense, making the technique more sensitive.The detection technique of gas used during my PhD was chosen after an extensive comparison of different techniques belonging to the SDLA. This technique is the QEPAS technique. It has shown since its invention in 2002, a high sensitivity and selectivity in gas analysis. The light source used in the QEPAS is a tunable diode laser (Laser SC), thus making the technique more selectively, by varying the wavelength of emission as a function of injected current and / or control temperature to be located on a line desired to detect. The detector is QEPAS of quartz tuning fork (QTF). The latter is very sensitive to small force applied by the acoustic wave, which makes the technique very sensitive to low concentrations. Several steps are required characterization to determine the characteristics of the laser diode and the QTF. After choosing the laser diode and the QTF, ideal for spectroscopy, we pass to the evaluation of the technique QEPAS in gas analysis. The detection limits of methane obtained with the technique are QEPAS 0.8 ppmv and 400 ppbv to 2.3 microns with a Fabry-Perot laser and a photonic crystal laser, respectively, and 100 ppbv to 3.3 microns with a DFB laser.This work has provided a powerful technique (sensitive, selective, cheap ...) in gas analysis
Ayoub, Anas. "Sources laser ultrarapides performantes dans le moyen IR et le Tz". Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR044.
Pełny tekst źródłaThe atome probe tomography is an instrument for analyzing matter in three dimensions with atomic resolution. This instrument relies on the effect of an electric field generated at the end of a sample cut into the shape of a nanoscale needle to evaporate the surface atoms which are collected by a two-dimensional detector. The measurement of the time of flight of the ions whose evaporation is triggered by an electrical or optical pulse makes it possible to measure the chemical composition in addition to the 3D localization of the atoms. In current atome probes, atomic evaporation is triggered by a high-speed laser emitting in the UV. However, the interaction of UV light with matter induces thermal heating which limits the mass resolution of the instrument and prevents its use for the analysis of fragile materials such as biocompatible components. This thesis work aims to study solutions to promote rapid evaporation while inhibiting unwanted thermal effects of the laser in atome probe. Our approach consists in exploiting ultrashort pulses in the mid-infrared or THz domain due to their high ponderomotive energy associated with low photon energy. This manuscript reports on the development of a bench for the generation and characterization of intense THz pulses. Coupling these radiations with a negatively polarized metallic nanotip has made it possible to characterize the near field induced at the surface of the nanotip, which is strongly modified by the antenna effect. The second part reports on the development of an ultra-fast laser source tunable in the mid-infrared around 3 mm using fluoride glass fibers
Helle, Marion. "Localisation du ganglion sentinelle au moyen de nanoparticules fluorescentes émettant dans le proche infrarouge : Application au cancer du sein". Phd thesis, Université de Lorraine, 2012. http://tel.archives-ouvertes.fr/tel-00762073.
Pełny tekst źródłaVivet, Nicolas. "Elaboration et caractérisation de films minces Cr2+:ZnSe nanostructurés pour la fabrication de microlasers émettant dans le moyen infrarouge". Phd thesis, Université de Caen, 2008. http://tel.archives-ouvertes.fr/tel-00347093.
Pełny tekst źródłaDans l'objectif de développer un laser compact pompé électriquement, des films minces de Cr2+:ZnSe ont été élaborés à température ambiante par pulvérisation magnétron radiofréquence d'une cible de SiO2 recouverte de morceaux de ZnSe et de chrome sous plasma d'argon pur, sur des substrats de verre, Si et GaAs.
Quelque soit le substrat, les films déposés sont constitués de ZnSe cubique quasi-stoechiométrique et présentent une structure colonnaire avec une forte orientation préférentielle dans la direction 111. Le recours à l'analyse combinée par diffraction X a permis de résoudre simultanément la texture, la structure et la microstructure d'un des films déposés. Le spectre de PL des films à température ambiante dans le domaine 2-3 µm, comparable à celui des cristaux de référence de Cr2+ :ZnSe, a été obtenu d'une part par excitation directe des ions Cr2+ (1.85 µm) et d'autre part par excitation indirecte en utilisant un laser visible. Les paramètres de dépôt (puissance radiofréquence, pression d'argon, quantité de chrome) ont été optimisés pour obtenir des films présentant une intensité de PL maximum dans le MIR.
Chazal, Richard. "Lignocelluloses de graminées : apports de la spectroscopie dans le moyen infrarouge et de l'empreinte enzymatique à leur étude structurale". Nantes, 2014. http://www.theses.fr/2014NANT2061.
Pełny tekst źródłaThe enzymatic cellulose-to-ethanol conversion applied to grass lignocellulosics is detrimentally affected by lignins and their cross-linking to hemicelluloses. Selecting grass cell walls less recalcitrant to enzymatic hydrolysis and monitoring their compositional changes during the process call for developing high throughput and informative methods. In the first chapter, the potential of Fourier transform mid infrared spectroscopy for the prediction of cell wall traits that could be targeted for improved saccharification was evaluated on a series of extract-free cell walls (EFCW) prepared from mature grass stems (maize, sorghum, wheat, bamboo, brachypodium). These samples were analyzed for lignins, carbohydrates, and p-coumaric and ferulic esters. In addition, a set of purified grass lignin standards was obtained from these samples by mild acidolysis and subjected to the same chemical analyses. Partial least square (PLS) analyses were applied to mid infrared and chemical data of 16 grass lignin standards and of 31 grass EFCW. The resulting models showed a good predictive ability with regard to the EFCW lignin content and to lignin structural traits revealed by thioacidolysis, as well as to the level of p-coumarate esters. By contrast, no satisfying model could be obtained to predict polysaccharide traits or ferulic esters. In the next future, the FTIR-based models built to predict important grass cell wall traits will be consolidated and improved by the addition of a wider range of grass samples. In the second chapter, the structural investigation of native arabinoxylans from maize EFCW samples (internodes, leaves, cobs) was carried out by enzymatic fingerprint, using an endoxylanase hydrolysis followed by HPAEC chromatography and ESI-ORBITRAP mass spectrometry of the resulting oligosaccharides. The same fingerprint was comparatively applied to hemicellulosic fractions (hemicelluloses A and B) isolated by the conventional extraction methods. The oligosaccharides obtained from EFCW and from isolated hemicelluloses displayed different substitution degree. While the enzymatic fingerprints of EFCW maize samples were diagnostic for their anatomical origin, they underestimated the more substituted arabinoxylan structures. However, the present results underline the great potential of enzymatic fingerprint performed on lignocellulosic step samples, without the time-consuming extraction conventionally employed for their structural investigation
Morvan, Marie. "Modèles de régression pour données fonctionnelles hétérogènes : application à la modélisation de données de spectrométrie dans le moyen infrarouge". Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S097.
Pełny tekst źródłaIn many application fields, data corresponds to curves. This work focuses on the analysis of spectrometric curves, composed of hundreds of ordered variables that corresponds to the absorbance values measured for each wavenumber. In this context, an automatic statistical procedure is developped, that aims at building a prediction model taking into account the heterogeneity of the observed data. More precisely, a diagnosis tool is built in order to predict a metabolic disease from spectrometric curves measured on a population composed of patients with differents profile. The procedure allows to select portions of curves relevant for the prediction and to build a partition of the data and a sparse predictive model simultaneously, using a mixture of penalized regressions suitable for functional data. In order to study the complexity of the data and of the application case, a method to better understand and display the interactions between variables is built. This method is based on the study of the covariance matrix structure, and aims to highlight the dependencies between blocks of variables. A medical example is used to present the method and results, and allows the use of specific visualization tools