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Lefebvre, Kim. "Technique de réutilisation de longueur d'onde optique dans des applications RoF basée sur les RSOA pour des communications bidirectionnelles OOK et OFDM". Master's thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/37718.
Pełny tekst źródłaLiu, Jingtian. "Shaping Strategies to Embrace Nonlinear Effects in Optical Fiber Communications". Electronic Thesis or Diss., Institut polytechnique de Paris, 2024. http://www.theses.fr/2024IPPAT007.
Pełny tekst źródłaThe main impediment in long-distance communications is nonlinear interference (NLI), stemming from nonlinear effects in optical fibers. While Digital signal processing algorithms offer partial mitigation, the inherent nonlinear nature of the fiber, coupled with predominant dispersion effects, continues to challenge the increase of transmission throughputs. Addressing nonlinearity at the information source through signal modulation technology is at the heart of our research. Traditional modulation schemes, as spectral efficiency climbs, such as QAM, become increasingly susceptible to NLI while their Mean Squared Euclidean Distance (MSED) diminishes. While multi-dimensional (MD) modulation yields improved linear and partial nonlinear gains, it has not yet demonstrated tangible benefits. On the other hand, the emergence of probabilistic constellation shaping (PCS), preferred for its enhanced linear gain and compatibility with conventional modulation hardware and software, introduces additional NLI. Consequently, the design of nonlinear-tolerant PCS is emerging as a pivotal research direction. Our thesis begins with a novel MD modulation for uniformly distributed signals. Then, we propose a novel approach combining MD with PCS to examine performance variations. Delving into PCS, we investigate the enumerative sphere shaping distribution matcher (DM), initially from an MD stance, and design a DM optimized for nonlinear tolerance over shorter distances. Subsequently, we introduce a new NLI measurement technique, accounting for dispersion effects. Integrating this with the sequence selection framework of PCS, we achieve successful long-distance transmission with notable nonlinear gains
Nanni, Jacopo. "High performance, low cost and low consumption Radio over fiber Systems for diversified communications applications". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1162/document.
Pełny tekst źródłaThis dissertation aims to analyze the possibility of improving in terms of cost and consumption the future Radio-over-Fiber (RoF) systems in different telecommunication scenarios, such as current and next generation of cellular networks and in other applications such as Radio Astronomy. The RoF system studied is hence composed of a Vertical Cavity Surface Emitting Laser (VCSEL) operating at 850 nm, standard single mode fiber (SSMF) and SiGe Heterojunction Phototransistor (HPT), adopting the technique called Intensity Modulation{Direct Detection which is nowadays the cheapest and simplest architecture for RoF. This dissertation describes in detail the multimode propagation within the SSMF (designed to operate only at 1310 nm and 1550 nm) which is present at 850 nm. Through a developed mathematical model, the two-modes propagation is described and the main phenomena involved are analyzed. In particular, the model focus on intermodal dispersion and modal noise which are considered the two main contributions of performance detrimental. The model developed is able to identify the main parameters which contribute to enhance the detrimental effects produced by intermodal dispersion and modal noise both in frequency and time domain. Starting from the model, possible techniques to improve the performances are then proposed. In particular, a pre-filtering technique is realized in order to avoid the excitation of the second order mode, allowing a quasi-single-modepropagation within the SSMF. The technique is theoretically and experimentally validated either for single radio frequency sinusoidal transmission either for bandpass signal transmission centered in radio frequency band. In particular it is demonstrated experimentally the possibility of increasing the modulationbandwidth of the RoF system, reducing at the same time the fluctuations of power and gain. Furthermore, the technique is validated in a real LTE transmission system, making the RoF technology proposed able to transmit 256-QAM LTE signal of 20 MHz bandwidth, confirming the possibility of using this technology to decrease the overall cost and consumption of the network. Further work hasbeen done on the mathematical model. In particular the two modes propagation is exploited reversely in order to characterize the chirp parameter of the VCSEL employed. Finally, the problem of coupling between fiber and opto-electronic devices is also discussed and investigated, in order to enhance theperformances while keeping low the cost. The possibility of utilizing a collective and passive ploymerbased structure for coupling the optical fiber with small area photodetectors and VCSEL is presented, showing important improvements on coupling efficiency and tolerance to misalignment
Holtz, Jürgen. "Codage pour les communications par fibres optiques /". Paris : Ecole nationale supérieure des télécommunications, 1994. http://catalogue.bnf.fr/ark:/12148/cb357781974.
Pełny tekst źródłaGuillory, Joffray. "Radio over Fiber (RoF) for the future home area networks". Thesis, Paris Est, 2012. http://www.theses.fr/2012PEST1083/document.
Pełny tekst źródłaThe evolution of the Home Area Network (HAN) is lead by the proliferation of connected devices inside the home and the deployment of high broadband access network which now allows the delivery of services that can exceed 1Gbit/s. To ensure efficient in-house exchanges, the HAN has to move rapidly toward multi-Gigabit/s connections, in particular the wireless connectivity generally preferred by the customers. Current wireless systems have limited capacities, but new radio standards delivering data-rates up to 7Gbit/s are emerging. Nevertheless, as they address the unlicensed millimeter-wave band, from 57 to 66 GHz, their radio coverage is limited to a single room. Indeed, at such frequencies, the free-space losses are high and the waves do not cross the walls. This thesis proposes to solve this problem by means of the Radio over Fiber (RoF) technology. This consists in capturing the 60GHz radio signals emitted in one room, converting them into optical signals for transmission through optical fibers, and reemitting them in another room. Thus, several RoF transducers will be installed in the home and interconnected by a suitable optical infrastructure to create systems acting at the same time as repeaters and as distribution systems. From the viewpoint of the HAN market, such systems will be competitive only if they are low cost. As a consequence, this work focuses on direct modulation with direct detection (IM-DD) at Intermediate Frequency (IF). In other words, the 60GHz signal is down-converted at a lower frequency around 5GHz before the laser modulation and up-converted to 60GHz after the photodetection. Concerning the optical fiber, silica multimode fiber (MMF) is privileged as it allows the use of low cost and largely available optoelectronic devices working at 850nm.The thesis proposes different RoF architectures, from point-to-point interconnecting two rooms to multipoint-to-multipoint acting as logical buses. After an analog characterization of the optoelectronic components, the RoF link and the domestic cable, these architectures are designed, built and characterized step by step using OFDM modulation according to existing wireless 60GHz standards. Real-time transmissions between commercial devices have also been performed to validate these architectures. Moreover, advanced RoF infrastructures are proposed. First, the RoF systems can be easily improved if the access to their optical media is managed by the radio MAC layer. This approach is therefore studied showing its feasibility. Secondly, an optical system, seen by users as a premium product, has to support the legacy home services commonly used as well as the new ones that could emerge in the future. Thus, innovative multiservice and multiformat infrastructures conveying on a unique optical cable wired IP data, broadcast terrestrial or satellite television, the 60GHz wireless connectivity, and specific formats as HDMI signals are proposed and tested
Audo, Frédéric. "Opto-alimentation et transmission de données par fibre optique pour les observatoires de fond de mer". Phd thesis, Université de Bretagne occidentale - Brest, 2012. http://tel.archives-ouvertes.fr/tel-00782502.
Pełny tekst źródłaLegros, Eric. "Photorecepteur integre pour transmission coherente sur fibres optiques". Paris 11, 1993. http://www.theses.fr/1993PA112413.
Pełny tekst źródłaBlayac, Sylvain. "Transistor bipolaire à double hétérojonction InP/GalnAs pour circuits de communications optiques à très haut débit". Montpellier 2, 2001. http://www.theses.fr/2001MON20039.
Pełny tekst źródłaCastan, Stéphanie. "Codage de canal pour les communications optiques". Limoges, 2009. https://aurore.unilim.fr/theses/nxfile/default/ca31ecf8-c9ba-423d-93f5-ebe0d7929315/blobholder:0/2009LIMO4021.pdf.
Pełny tekst źródłaThe work done in this study focuses on forward error correction used to compensate for performance degradations in fiber optical links, mainly corrupted by the quadratic photo detection process. When we consider a single user transmission, this process has an impact on the photo detected signal statistic, which can be represented as a chi-square function. Taking into account this statistic, the iterative decoding used for LDPC codes is modified in order to optimise the performance. In the case including Optical Code Division Multiple Access, mainly disrupted by Multiple Access Interference, photo detection induces beatings called beat noise. Studying the photo detected signal statistic leads us to establish a theoretical model based on a mixture of chi-square distribution. The error correction performance has been optimised by taking into account this model in the decoding process, which permits considering an application to multimedia transmissions
Zaganiaris, Alcibiade. "Contribution à l'évolution des techniques des communications optiques : des composants aux systèmes opérationnels". Lyon 1, 1991. http://www.theses.fr/1991LYO19002.
Pełny tekst źródłaRajanona, Patricia. "Problèmes de synthèse et de réalisation des traitements sur extrémités de fibres optiques pour multi-démultiplexage spectral". Aix-Marseille 3, 1994. http://www.theses.fr/1994AIX30001.
Pełny tekst źródłaFRITSCH, CLEMENT. "Dispostif de determination du deplacement des pieds d'arcs sur des pastilles de contact par sondes optiques". Paris, CNAM, 1991. http://www.theses.fr/1991CNAM0136.
Pełny tekst źródłaKhayatzadeh, Ramin. "Convergence des technologies optique et radio pour la génération dédiée aux communications aux fréquences supérieures à 60 GHz". Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT074/document.
Pełny tekst źródłaThis Ph.D. investigates the radio over fiber communication systems at mm-wave frequencies higher than 60 GHz. The thesis elaborates on three crucial issues in these systems including:phase noise measurement of unstable optically generated mm-wave signals, elimination ofphase noise impact on performance of radio over fiber systems using non-coherent down conversion technique, and studying the amplitude noise impacts on performance of system based on these detectors. In the first part of this work, a new digital phase noise measurement technique is presented which is able to extract the phase noise of any unstable mm-waveoptically generated signal. This technique is able to measure the phase noise for a widerange of offset frequencies from close-in phase noise to far noise floor by adapting frequency resolution of measurement and without considering small angle approximation. In the second part, we present a radio over fiber system at mm-wave frequency based on non-coherent electrical frequency down conversion stage using an envelope detector which is robust against phase and frequency fluctuations of the optically generated carrier signal. Finally, a the oreticaland experimental study of amplitude noise impact on performance of radio over fiber systemsbased on non-coherent receivers is presented. In this study, a simulation technique based ontheory is developed which is able to determine, among different optical and electrical noise, the one which has the dominant effect on EVM results. This simulation technique is based onobserving the EVM evolution versus received optical power
Vergnol, Eric. "Convertisseur millimétrique optique à bande latérale unique pour le transport radio sur fibre". Brest, 1999. http://www.theses.fr/1999BRES2032.
Pełny tekst źródłaKamoun, Lofti. "Contribution à l'étude des réseaux locaux de transmission d'images sur fibres optiques". Bordeaux 1, 1992. http://www.theses.fr/1992BOR10602.
Pełny tekst źródłaPhan, Huy Minh Châu. "Développement de composants transducteurs et de dispositifs aux fonctionnalités innovantes fondés sur la technologie des fibres microstructurées et des réseaux de Bragg". Limoges, 2006. http://aurore.unilim.fr/theses/nxfile/default/25f913c0-6636-4f4a-8cd0-683c177cea3b/blobholder:0/2006LIMO0012.pdf.
Pełny tekst źródłaThis work lies within the scope of optical fibers sensors development based on microstructured fibres. The inherent advantages of these special fibres, resulting from the innovative technology, are due to related to the presence of air channels within the cladding. Telecommunication industry as well as instrumentation can draw profit from possibilities offered by “custom” design of this type of guide, achieved through the stack of rods and silica capillaries, each of them constituting many zones of the preform from which would be manufactured microstructured fibers. Thus, it is possible to use the interaction between the electromagnetic field of the optical wave and the liquid medium, even solidified, present in the aforementioned channels to produce transducers or active light modulators for example. Beyond, fibre design makes it possible to optimize the measurement sensitivity to the required parameters. Finally, taking advantage of Bragg grating photowritten in the fibre core adds transducing functionality through spectrally multiplexed remote measurements. This manuscript describes short-period Fiber Bragg Grating and Tilted Fiber Bragg Grating photowriting in a microstructured fiber and sensitivity study of its spectral resonance shift according to the refractive index of the medium inserted into the fiber holes, and this for several fiber designs. The principle of measurement is to follow the wavelength shift of Bragg resonance according to the refractive index of the medium inserted into the holes. Initially, microstructured fiber characterization, manufactured through the MONTE CRISTO project consortium (6-hole fiber, then 18-hole fiber) was carried out through the Fiber Bragg grating photowriting and the cross comparison between experimental and simulation results of a modal analysis. So, adding to the commercial software FEMLab (finite-elements type) a dedicated simulation tool based on the localized function method has been developed. For a given design of hole geometry, it is possible to find out the sensitivity versus refractive index of the medium inserted in the channels (sensitivities obtained, respectively with 6 and 18-hole fibers, are 4×10-3 r. I. U/ pm and 7×10-4 r. I. U/ pm, with a refractive index close to 1,33). This tool allowed us to model and design a specific microstructured fibre made up of three large channels close to the core. This design of hole geometry largely improved the interaction between the electromagnetic field and the medium inserted and in fine increased the sensitivity of the Bragg grating resonance to the refractive index (sensitivity of 3×10-5 r. I. U/ pm for a refractive index close to 1,33). In a second time, fluids with calibrated refractive index were inserted by capillarity into the fiber channels. The spectral evolution versus index of refraction of the Bragg grating photowritten in the Ge doped core microstructured fiber made it possible to determine precisely the spectral sensitivity to the refractive index. Another approach based on Tilted Fiber Bragg Grating was also investigated. This initiative (consisting in modifying the fibre profile and thus its optogeometric characteristics), as a complement to the first solution, allows to significantly increase the measurement sensitivity by considering the spectral evolution of one of the high order mode with the index of refraction. Beyond, a multi-cycle ‘reversible’ refractometric device, allowing insertion and extraction of liquids to be analyzed in the fibre channels was developed and characterized, demonstrating the feasibility of the global solution of refractive index measurements with microstructured fibers. In complement to index measurements, a preliminary study was carried out to highlight the possibility to increase the thermal sensitivity of a Fiber Bragg Grating photowritten in a microstructured fibre, while inserting into channels a fluid whose index is higher than a threshold value depending on hole geometry. As a consequence, doubling the thermal sensitivity of the Bragg grating is achievable for a fibre profile and a given refractive index. In the future the way is wide open for a new type of sensors based on Fiber Bragg gratings (or Tilted Fiber Bragg gratings), optimized microstructured fibers and fluid devices to insert or extract liquids used as transducers themselves or to be analyzed. The fields of potential application cover numerous sectors such as biology, chemistry or environment analysis
Nicole, Jean-François. "Étude sur les capteurs à fibre optique pour l'instrumentation de structures de génie civil". Sherbrooke : Université de Sherbrooke, 2000.
Znajdź pełny tekst źródłaVallée, Jean-Michel. "Source laser accordable jumelant photonique sur silicium et fibre optique". Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69037.
Pełny tekst źródłaThis master's thesis is on the design of a hybrid laser combining optical bers and the technology of silicon photonics. The main objective is to achieve a laser with great control and exibility over its emission parameters and with good performances for the eld of optical telecommunications. Until now, several approaches leading to laser integration on the silicon photonics have been demonstrated. Unlike integration approaches which aim to produce the most compact source possible, the chosen approach aims to produce a high-performance laser which exploits both the optical amplication performance of the doped bers as well as the potential of light processing and precision that oers the silicon photonic platform. The operating principle as well as the theoretical models of dierent optical devices accessible thanks to the silicon photonics are presented in detail. These devices allowing optical connement at the 100-nanometer scale level as well as the manipulation of light are key elements in the design of optical lters for the laser cavity. The performances of a Vernier lter on silicon are analyzed by means of numerical simulations. Two types of hybrid lasers are presented in this document. The rst is a multimode laser allowing a selection of the spectral spacing between its modes. The second type of laser is a single-mode laser operating at 2000 nm and tunable over a range of 100 nm. In the rst case, the amplication medium of the cavity is composed of an optical ber doped with erbium while in the second, it is a ber doped with thulium.
Gheivelis, Nicolas. "Influence d'une soudure sur les caractéristiques de transmission de la liaison entre une fibre à profil parabolique ("MCVD") et une fibre à profil trapézoidal ("plasma-ALPD")". Paris 11, 1986. http://www.theses.fr/1986PA112019.
Pełny tekst źródłaA splice is a permanent connection between two optical fibers, made by an electric arc, an oxydric torch and/or a CO₂ laser. This THESIS analyses the influence of an arc fusion splice on the transmission characteristics of a join between a parabolic profile fiber ("MCVD") and a trapezoidal. The trapezoidal profile fibers are fabricated by the ALPD process (Axial-Lateral Plasma Deposition) using an atmospheric pressure plasma torch and fluorine as dopant. The trapezoidal profile results in an initial constant core region, a gradient zone and an ''index barrier" in the core-cladding interface. These fibers are adapted to the needs of a local subscriber network because they are cost-effective for these particular required characteristics (Att ≤ 3dB/km, Bandwidth ≈ 200MH km, Num. Aperture ≈ 0. 20). We show that splice lasses between parabolic fibers and trapezoidal fibers are approximately 0. 12 dB due to a) intrinsic parameters (profile deformation, numerical aperture difference, "index barrier" effect) and b) extrinsic ones (angular and lateral misalignments). In the same way we demonstrate that the bandwidth of the link which consists from the two different, above-mentioned fibers is a little higher than the concatenated bandwidth of two identical fibers. It is due to the mode conversion after the splice caused by a strong coupling of modes as we calculate using the concatenation factor δ (δ = 0. 5 – 0. 7). The Numerical aperture obtained after the splice approaches that of the receiving fiber, except in the case of a failed splice in which the Numerical aperture considerably increases. In order to improve the understanding of propagation change after splice, the differential mode delay (D. M. D. ) data are analysed. This measurement appears to be a precise image of how modes propagate after the splice in this particular link. Finally, in the conclusion the different local network structures are presented, together with some complementary studies of our experimental work, in order to confirm the choice of introducing the trapezoidal profile fiber in the public subscriber network
Tortech, Blandine. "Effets des radiations sur des fibres optiques dopées erbium : influence de la composition". Phd thesis, Université Jean Monnet - Saint-Etienne, 2008. http://tel.archives-ouvertes.fr/tel-00366057.
Pełny tekst źródłaMaguis, Séverine. "Biocapteurs à fibres optiques fondés sur les réseaux de Bragg en angle fonctionnalisés". Ecully, Ecole centrale de Lyon, 2008. http://www.theses.fr/2008ECDL0031.
Pełny tekst źródłaThe purpose of this research work is to investigate the possibility of using tilted fiber Bragg grating technology to provide an alternative solution for molecular detection in aqueous solutions, suitable for in situ measurements and simpler to use than conventional monitoring instruments. As a tilted ber Bragg grating is sensitive to any change in the refractive index of the medium surrounding the cladding, this refractometer can be used as a transducer for biosensing applications if the silica ber surface is biofunctionalized. One of the great challenges to be met in the preparation of biosensors is the strategy for immobilization of the biospeci c molecule onto the transducer. The binding of the target molecule to the immobilized probe results in changes in the thickness and/or the refractive index of the biofilm, which modulates the spectral response of the grating. The sensitive area of the refractometer combines two complementary functions: on the one hand, the biospeci c biofilm enables one to detect the target molecule by converting binding events into physical changes of the sensitive layer; on the other hand, the tilted ber Bragg grating translates this thickness / refractive index modi cation into a spectral modulation. Bovine serum albumin (BSA) and anti-BSA are used to assess the performances of the tilted- ber-Bragg- grating-based biosensors. The implementation of a fast measurement technique has contributed to improve the performances of the detection process for low concentrations of target molecules in solution (10 -5 voire 10 -6 g/L). Therefore, the early results seem promising and could provide a conceptual basis for future research: it hbeen demonstrated that a label-free biosensor based on a tilted ber Bragg grating is able to follow, in real 2. Time, biological interactions taking place at the surface of the sensitive bio lm. Therefore, this study provides a base for future work regarding, for instance, water pollution monitoring
JOSSET, JEAN-LUC. "Amelioration du pouvoir separateur par traitement du signal en reflectometrie sur fibres optiques". Rennes 1, 1989. http://www.theses.fr/1989REN10098.
Pełny tekst źródłaTrisorio, Alexandre. "Développement d'une source laser femtoseconde de quelques cycles optiques pour la génération d'harmoniques sur cible solide". Paris 11, 2008. http://www.theses.fr/2008PA112316.
Pełny tekst źródłaResearch at the « Laboratoire d’Optique Appliquée » (LOA) is oriented on the development of ultra-short and ultra-intense laser sources and on their application for laser-matter interaction experiments. Indeed, ultra-short laser sources are a nice tool allowing experiments in several areas of high field physics like particle acceleration, secondary X ray and Gamma sources, time resolved study of chemical processes… Among them it is worth considering high harmonic generation in gases or in over dense plasmas (solid state targets). The generation and the phase matching of these harmonics open the way to the production of attosecond light pulses that can be a nice probe to study ultra-fast processes like electron dynamics in atoms. The scientific work of the « Physique du Cycle Optique » (PCO) group is mainly devoted to this last thematic. « En effet » theoretical work have demonstrated that attosecond pulse generation in the relativistic regime is possible with an unprecedented efficiency of 10-3. It is now possible to obtain relativistic intensities (1018 W. Cm-2) with kHz lasers delivering few-cycle pulses (with a duration of less than 10 fs at 800 nm). One particular interaction regime, called « 3 regime » has been highlighted theoretically. In this regime, a few-cycle light pulse is focused on a solid state target, the focal spot size is in the order of the laser wavelength. All the energy is then concentrated in a focal volume of the order of the wavelength to the power 3. High order harmonics are then produced due to the interaction of the light pulse with the generated over dense plasma. In this case, the efficiency can reach 10-1. In order to generate experimentally such a type of harmonics, one have to build a laser source delivering few-cycle pulses with an energy of more than 1 mJ at a repetition rate of 1 kHz. Moreover, two additional constrains have to be overcome. The first one is the temporal contrast of the laser pulse: it has to be more than 1010 in order to avoid unwanted pre-ionisation of the target. The second one is the stabilisation of the relative phase between the maximum of the electric field and the maximum of the envelope of the pulse. Indeed, for few-cycle pulses, the harmonic generation process is sensitive to this Carrier-Envelope phase Offset (CEO phase). This PhD thesis’ work is integrated in the following goal: the design, development and characterization of a few-cycle, high contrast and CEO phase stabilized laser source for harmonic generation in the relativistic regime. We performed a complete characterization of the performances of the commercial system. We experimentally validated an hybrid pulse compression scheme on this CPA laser source. This compressor made of a prisms delay line and chirped mirrors seems to be a good choice. In fact, this solution allows to decrease non-linear effects due to the prisms’ material. Compressed pulse energy was brought to 1. 26 mJ and it’s FWHM duration was decreased to 24 fs. This improvement lead to a 53 GW laser source which is 1. 8 times better than the commercial system. Temporal contrast is quite good and CEO phase stabilization was performed leading to a phase jitter of 200 mrad. We also developed and characterized a CPA laser source delivering 22 fs, 4 mJ light pulses at a repetition rate of 1 kHz. This laser source uses the oscillator, the stretcher and the amplifier stage of the previously described commercial system. After the first amplifier, we added a home-made multi-pass amplifier. This amplifier allows to increase the amplified pulse energy to 6 mJ. Temporal pulse compression is done with an hybrid compression scheme (prisms line + chirped mirrors). This compressor associated with the DazscopeTM apparatus (allowing spectral phase measurement and optimisation) allow the generation of Fourier transform limited pulse duration showing the quality of the temporal pulse compression. The picosecond contrast (107) and the pulse energy stability (2. 6 % rms) are satisfying. Concerning the beam quality, the spatial intensity profile is not Gaussian, however in the far field, the beam profile is good enough and usable. The initial goal, consisting of the development and characterization of a sub-25 fs, multi-mJ laser source at 1 kHz is reached. Moreover this laser system is successfully used for few-cycle pulse generation thanks to non-linear techniques. This laser source is used to produce sub-10 fs pulses, our choice is to use the hollow fibre technique to generate such pulses. We succeeded in generating 5 fs pulses carrying a 172 GW power with a repetition rate of 1 kHz. The hollow fibre technique seems to be a robust way to produce this type of pulses. The main advantage is the excellent mode quality thanks to the guiding into the fibre. In addition, since the output of the fibre is fixed, the beam pointing stability is enhanced. In order to obtain more energetic pulses, experiments are still in progress with a fibre with a bigger core in order to inject the 4 mJ pulses out coming from the CPA source. We want to obtain 5 fs pulses with an energy of 2 mJ which would be a 0. 5 TW laser source at a 1 kHz repetition rate. The filament self-compression technique seems to be a less interesting technique for high energy few-cycle pulse generation mainly due to pulse energy limitation inherent to the filamentation process. It also seems that the pulse duration is varying across the beam. However, the self-compression regime can be interesting for applications that need only low energy pulses. Finally we did experiments that lead to two new techniques allowing to influence the multi-filamentation regime. The first one is the use of a circularly polarized beam that allows to increase the energy and the beam pointing stability of the filamenting pulses. The second one is the use of a deformable mirror in order to control dynamically the number of out coming filamenting pulses by changing the wavefront of the initial laser pulse. These methods can have an application in the design of few-cycle, multi-beam laser source
Petitjean, Michae͏̈l. "Etude de microrésonateurs optiques par modes de galerie couplés à des fibres polies sur le côté". Limoges, 2000. http://www.theses.fr/2000LIMO0006.
Pełny tekst źródłaRamdani, Jamal. "Contribution à l'étude des phénomènes de photoconduction sur matériaux contraints GaInAs/GaAs : application à la réalisation de têtes optiques intégrées aux longueurs d'onde 1,3um-1,55um". Lille 1, 1987. http://www.theses.fr/1987LIL10063.
Pełny tekst źródłaRONDEAUX, FRANCOISE. "Etude sur le revetement optique des fibres optiques plastiques : influence des phenomenes de diffusion". Paris 6, 1989. http://www.theses.fr/1989PA066749.
Pełny tekst źródłaGUYARD, DAVID. "Metrologie des diagnostics sur signaux transitoires rapides, appliquee aux transmissions analogiques par fibres optiques". Caen, 1996. http://www.theses.fr/1996CAEN2076.
Pełny tekst źródłaOllier, Eric. "Micro commutateur opto-mécanique intègre sur substrat de silicium pour réseaux de fibres optiques". Grenoble INPG, 1995. http://www.theses.fr/1995INPG0163.
Pełny tekst źródłaRochette, Pierre. "Capteurs à fibre optique intégrés à des matériaux composites pour le génie civil: Essais et simulations sur éprouvettes cruciformes". Sherbrooke : Université de Sherbrooke, 2002.
Znajdź pełny tekst źródłaGeorgescu, Bogdan Iulian. "Etude des effets parasites dans les transistors à effet de champ à hétérojonction (HFET) sur substrat InP". Lyon, INSA, 1998. http://www.theses.fr/1998ISAL0108.
Pełny tekst źródłaNowadays optical communications systems provide a very large proportion of the communications links. Their evolution is conditioned by the existence of high performance optoelectronic circuits and devices. The optical and electrical properties of the III-V INP – based materials, well adapted to the transmission windows of the silica optical effects, are very interesting for applications in high-speed optoelectronic integrated circuits. Despite their performances, INP based HFET's presents some important anomalies like the kink effect, the dispersion of the drain source conductance with the frequency and the low frequency noise. These behaviors could be induced by the presence of deep traps that are generally perturbations in the crystal lattice. It is important to understand and minimize these phenomenon’s in order to increase the performances of the devices for photo detection applications. Our study could be divides in two parts: a study of the deep levels, which was performed using current transient spectroscopy, the dispersion of the drain-source conductance measurements and the low frequency noise measurements. The results concerning the activation energies and captures cross sections obtained from these methods are in general similar, so these three techniques are suitable for deep level characterization on complex structures like HFET's and they can be used in a complementary manner. The second part consists in a detailed analysis of the kink effect. We examined the behavior at this p parasitic effect with the temperature, with the frequency excitation and under monochromatic excitation. These results correlated with the evolution of the gate current with the temperature and with the photo capacity measurements show that the kink effect in mainly related to the deep traps
Bouhamri, Zine-Abidine. "Transmission multi-standards sur lien optique bas-coût". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00957588.
Pełny tekst źródłaFracasso, Bruno. "Des interconnexions holographiques à l'aiguillage dynamique pour les réseaux de communications optiques". Habilitation à diriger des recherches, Université de Bretagne Sud, 2010. http://tel.archives-ouvertes.fr/tel-00691577.
Pełny tekst źródłaYi, Lilin. "Ralentissement de la lumière par effets non-linéaires dans les fibres optiques pour les systèmes de communications à haut débit". Paris, ENST, 2007. http://www.theses.fr/2007ENST0037.
Pełny tekst źródłaSlow light, referring to slowing down the propagation velocity of the light through engineering the material dispersion or waveguide dispersion of the medium, is a promising technology for optical buffering and packet synchronization in future all-optical communication networks. Recently, slow light in fibers are rapidly developing for their compatibility with fiber-optic communication systems, where the fiber nonlinearities such as stimulated Brillouin scattering (SBS), stimulated Raman scattering (SBS) and parametric process are used to shape the material dispersion of the fiber so as to realize the slow light based on the well-known Kramers-Kronig relationship. What’s more, for being compatible with the present 10-Gb/s optical communication systems, the system performances of 10-Gb/s signals delayed in the fiber nonlinearities based slow light should be thoroughly evaluated. In this thesis, we utilize the narrow band parametric process and broadband SBS in fiber to realize the tunable delay of 10-Gb/s signals. We evaluate the performances of the slow-light delay lines by measuring the maximal delay time, the fractional delay and the signal quality such as eye opening and bit-error-rate (BER) of the delay signal, and optimize the signal quality by minimizing the slow-light induced distortions
Fernandez, Fernandez Alberto. "Photonics for nuclear environments from radiation effects to applications in sensing and data-communication". Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210843.
Pełny tekst źródłaMartinez, Valérie. "Influence des effets thermiques et mécaniques sur la relaxation des préformes et des fibres optiques à base de silice : étude par diffusion de la lumière et par diffusion des rayons X". Lyon 1, 2004. http://www.theses.fr/2004LYO10181.
Pełny tekst źródłaMaria, Jérôme. "Dynamique des lasers auto-impulsionnels basée sur les propriétés d'amplification et d'absorption saturable de fibres optiques dopées". Nice, 2009. http://www.theses.fr/2009NICE4092.
Pełny tekst źródłaWe report in this thesis the study of the dynamic of self pushing laser with the aim of optimizing an all fibber passively Q-switched laser (LPQS) by saturable absorber. This work was both numerical with the simulation of a LPQS model (study of the localisation of saturable absorber in cavity…) and experimental with fiber and laser cavities characterisations. We mainly focused on ytterbium (Yb3+), the gain media, and chrome (Cr4+), the saturable absorber media. First, an original study which consists to fit experimental and simulated data of non linear transmission of saturable absorber allowed to estimate the room temperature lifetime of chromium in silica fibber less then 1 ns, well shorter than lifetime of Cr4+-doped crystal. Nevertheless, we experimentally showed that such a poorly efficient saturable absorber (with a very short lifetime) can stabilize chaotic self pulse generated by ytterbium fibber (Sustain Self Pushing, Self Mode Locking). We thus managed to make the first self-pulsing all fibber Yb3+ : Cr4+ laser. Sub-nanosecond pulses with 4W peak power were obtained
YATAGHENE, AREZKI. "Surveillance de la temperature par reflectometrie optique a correlation sur fibre dopee holmium". Paris, CNAM, 1994. http://www.theses.fr/1994CNAM0173.
Pełny tekst źródłaBoldyreva, Ekaterina. "Mesures réparties par réflectométrie fréquentielle sur fibre optique". Phd thesis, Toulouse, INPT, 2016. http://oatao.univ-toulouse.fr/18709/1/Boldyreva_Ekaterina.pdf.
Pełny tekst źródłaBenzazaa, Mostafa. "Etude d'architectures de systèmes de transmission de signaux ULB RF et millimétriques avec lien optique : application à la Radio-sur-Fibre". Paris 6, 2011. http://www.theses.fr/2011PA066218.
Pełny tekst źródłaBatal, Ahmed. "Génération optique de microondes par battements de deux ondes lasers stabilisées sur une référence commune". Limoges, 1997. http://www.theses.fr/1997LIMO0022.
Pełny tekst źródłaGuy, Martin. "Conception d'un contrôleur de fréquences optiques basé sur l'utilisation d'un guide d'onde non linéaire, applications aux systèmes de communications optiques multifréquences". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq25419.pdf.
Pełny tekst źródłaGatti, Sylvain. "Inscription laser UV pulsé sur nouveau matériau hybride pour codeurs optiques intégrés". Phd thesis, Montpellier 2, 2007. http://www.theses.fr/2007MON20238.
Pełny tekst źródłaLa technologie sol-gel a déjà démontré son potentiel. Un nouveau matériau sol-gel hybride à polymérisation cationique de type Epoxy a été développé dans le but de la simplification de la synthèse et de l'amélioration des performances en particulier l'adhérence.
Ce travail a pour objectif le développement d'un banc d'écriture laser UV dans une couche Epoxy et l'établissement du protocole de fabrication associé. Ce procédé de polymérisation locale est une alternative prometteuse aux techniques lithographiques par masque.
Ce nouveau banc utilise un laser pulsé travaillant à faible longueur d'onde pour une meilleure résolution et une meilleure polymérisation.
Ce travail a montré la faisabilité de circuits complexes de type multiplexeurs WDM avec un procédé d'inscription à faible coût. Nous avons réalisé les premiers prototypes de circuits dédiés à la sélection multiple de longueurs d'onde pour le (dé)codage du CDMA optique spectral.
Gatti, Sylvain. "Inscription laser UV pulsé sur nouveau matériau hybride pour codeurs optiques intégrés". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2007. http://tel.archives-ouvertes.fr/tel-00258256.
Pełny tekst źródłaLa technologie sol-gel a déjà démontré son potentiel. Un nouveau matériau sol-gel hybride à polymérisation cationique de type Epoxy a été développé dans le but de la simplification de la synthèse et de l'amélioration des performances en particulier l'adhérence.
Ce travail a pour objectif le développement d'un banc d'écriture laser UV dans une couche Epoxy et l'établissement du protocole de fabrication associé. Ce procédé de polymérisation locale est une alternative prometteuse aux techniques lithographiques par masque.
Ce nouveau banc utilise un laser pulsé travaillant à faible longueur d'onde pour une meilleure résolution et une meilleure polymérisation.
Ce travail a montré la faisabilité de circuits complexes de type multiplexeurs WDM avec un procédé d'inscription à faible coût. Nous avons réalisé les premiers prototypes de circuits dédiés à la sélection multiple de longueurs d'onde pour le (dé)codage du CDMA optique spectral.
Planes, Isabelle. "Performances des capteurs à fibres optiques basés sur les diffusions Brillouin, Rayleigh et Raman en environnement sévère". Thesis, Lyon, 2019. http://www.theses.fr/2019LYSES048.
Pełny tekst źródłaThis thesis was carried out in collaboration between Andra (The National Agency for the Management of Radioactive Waste) and the Hubert Curien laboratory (Joint Research Unit CNRS 5516) of the Jean Monnet University of Saint-Étienne.In this work, I evaluated the performance of fiber optic sensors for monitoring the geological disposal site of long-lived radioactive waste (Cigéo project). This application requires regular, remote and distributed monitoring of the evolution of different quantities of interest such as: temperature, deformation and the presence of hydrogen (as well as their combinations) in a severe radiative environment. The proposed solution is based on the follow-up of optical signatures evolution of these wave-guides via backscatter studies: Brillouin, Rayleigh, and Raman.In order to answer this problem, several interrogation systems have been tested (used). According to their specificities, they are differentiated by: their types of analysis, their spatial resolutions, their optical budgets and scopes...The selection of the studied optical fibers is a key element for this type of application as they have to withstand these extreme environments over long periods of time. In this work, I studied the responses of optical fibers containing different dopants, in particular Ge and F. I quantified the effects of gamma radiation, temperature, deformation and the presence of hydrogen on the quality (sensitivitiy) of the distributed measures.My work has identified the optical fiber type to be used for these harsh environments. The interrogators’ responses are driven by these fiber types as well as their lengths and, consequently, make it possible to clearly define the dimensions of the areas to be monitored. The qualities of the measurement are governed by the choice of several parameters and in particular: the pulse duration, the power injected into the fiber, the frequency steps, the measurement duration ... these elements have a direct impact on the final resolutions (spatial and frequency) of measured quantities. Particular attention must be attached to these criteria
Erbeia, Catherine. "Conception et réalisation d'un capteur interférométrique de déplacement intégré sur substrat silicium et connecté par fibres optiques". Grenoble INPG, 1990. http://www.theses.fr/1990INPG0064.
Pełny tekst źródłaMauroy, Valérie. "Élaboration de fibres optiques nanostructurées dopées aux ions de terres rares : influence des paramètres de fabrication sur la synthèse et la croissance des nanoparticules". Nice, 2012. http://www.theses.fr/2012NICE4047.
Pełny tekst źródłaErbium-doped optical fibres are commonly used to realize amplifiers. To control and modify erbium spectroscopic properties in these silica-based optical fibres we study an original way that consists in encapsulating ions into oxide nanoparticles obtained in-situ, directly during MCVD process. The modification of the erbium local environment allows to modify spectroscopic properties. These nanoparticles appear during the fabrication with the incorporation of a nucleation agent. Thermal cycles necessary to the perform fabrication ensure therefore to activate a spontaneous phase separation? This thesis aims to study the effect of different fabrication parameters, such as nucleating agent concentration in the doping solution or consolidation and collapsing phases, on the nanoparticle characteristics and erbium spectroscopic properties. In this manuscript, this study of the different parameters is organised in two axes : material composition an thermal cycles. Nanoparticles have mainly been characterised by Scanning Electron Microscopy (SEM). Erbium spectroscopy has been analysed by means of emission spectrum measurements as well as measurements of the 1,5 μm fluorescence lifetime. Spectroscopic modifications, i. E. Emission spectrum broadening of 40 until 60 %, have only been obtained for fibres that exhibit particles with high mean diameters (50 nm). Transparency criteria could only be satisfied while manipulating particle density
Heili, Manon. "Influence de l’histoire thermique sur la diffusion optique dans les préformes et les fibres optiques GeO2-SiO2 : F". Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112272.
Pełny tekst źródłaOptical fibers are inevitably present in telecommunications and Internet access networks. Long glass threads made of ultra-pure vitreous silica, they allow to relay information on long distances in the form of light signal. Despite their good transmission capacities, the reduction of optical losses remains an economical stake. Indeed, under a certain attenuation, it is possible to avoid amplifiers located in hardly accessible area where their setting is very expensive. The objective of this work is thus to explore new ways allowing to reduce significantly optical signal attenuation.The silica is a specific element for optical applications because of its physical chemistry properties (high transparency from IR to UV, strong mechanical resistance,…). Adding components in silica glass changes its characteristics (viscosity, density,…) without strong deterioration of optical properties. Especially, the addition of fluorine decreases the refractive index whereas germanium oxide GeO2 increases it. However, the glass structural disorder increases, and, therefore the optical attenuation as well. The disorder depends on thermal history. It is described by means of fictive temperature Tf that corresponds to the temperature at which the glass structure is frozen. The Tf of glass determines many material properties such as the fluctuations of refractive index and density. Rayleigh scattering is the main reason of optical losses in optical fibers, representing ~90% at 1550 nm wavelength. This scattering originates from the dielectric constant fluctuations, which contain two kinds of contributions: the density and the concentration fluctuations. By applying a thermodynamics approach, another term is suggested to complete this description: the fictive temperature fluctuations, resulting from a distribution of glass relaxation times. This approach highlighted importance of studying the relationship between density ρ and Tf on one hand, and between index n and Tf on the other hand, in order to reduce the Rayleigh scattering losses.In optical fiber process, Tf is essentially defined by the drawing conditions, i.e. furnace temperature, fiber drawing tension and speed. An experimental study allowed distinguishing the impact of these conditions on scattering losses in single mode conventional fibers. The knowledge about the origin of scattered objects (sizes and shapes) in fibers with different thermal histories has been made deeper. Ideally, it should be better to be disconnected from the drawing conditions.Contrary to the other oxide glasses, silica glass presents an anomalous behavior for its density: this one increases with fictive temperature. This anomaly disappears by adding a certain amount of chemical elements (F, Cl, GeO2, but not TiO2) in the material. We showed that some compositions, by deleting sensitivity of Rayleigh scattering to Tf, allows minimizing optical losses in the fibers family we studied. Raman spectroscopy has been then used in order to understand structural origin of this anomaly. Measurements revealed that D1 and D2 bands, which are related to small tetrahedral membered rings vibrations in glass, are not correlated to the macroscopic density. Consequently, they are not a reliable signature of densification phenomenon in binary glasses. Supplementary studies about the silicon coordination in the network are needed to conclude on structural origin of the silica anomaly
Pecci, Pascal Kennis Patrick. "Conception, fabrication et analyse d'une source intégrée laser-modulateur électro-absorbant à ondes progressives pour des transmissions optiques à haut debit à 1.55 [micro]m sur InP". [S.l.] : [s.n.], 2000. http://www.univ-lille1.fr/bustl-grisemine/pdf/extheses/50376-2000-484-485.pdf.
Pełny tekst źródłaPecci, Pascal. "Conception, fabrication et analyse d'une source intégrée laser-modulateur électro-absorbant à ondes progressives pour des transmissions optiques à haut debit à 1. 55 [micro]m sur InP". Lille 1, 2000. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2000/50376-2000-484-485.pdf.
Pełny tekst źródłaPuis, nous nous focalisons sur la conception du composant. Une premiere version est concue numeriquement afin de connaitre les parametres electriques de base du composant (indice de propagation n e, attenuation e, impedance caracteristique z c) et leur influence sur le fonctionnement. Apres analyse, une seconde version est realisee, permettant d'augmenter z c ce qui diminue la tension de commande et limite les pertes. Le chapitre 3 s'interesse a la fabrication des composants qui sont ensuite mesures et analyses (chapitre 4). Nous decouvrons ainsi les cles du monolithe (importance de z c et e, faible influence de n e) et comment les maitriser. En conclusion, les idees sur l'ilmtw ne sont plus preconcues mais concretes : la source integree possede une puissance de sortie optique de 1 mw (0 dbm) avec une monomodalite aussi bien transverse que longitudinale et un taux d'extinction de 20 db pour 2 vpp. Ses performances actuelles en termes de bande-passante et gain en tension sont comparables a celles des sources a electrode discrete, mais une legere modification permettrait un gain en performance de 30%
De, Valicourt Guilhem. "Conception, fabrication, et évaluation de modulateurs déportés pour les réseaux d'accès et radio sur fibre". Phd thesis, Télécom ParisTech, 2011. http://pastel.archives-ouvertes.fr/pastel-00677397.
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