Дисертації з теми "Nonlinear Raman"
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Chen, Xueqin. "Human skin investigations using nonlinear spectroscopy and microscopy." Thesis, Ecole centrale de Marseille, 2014. http://www.theses.fr/2014ECDM0014/document.
Повний текст джерелаSkin is an organ that envelops the entire body, acts as a pivotal, efficient natural barrier to- wards various invaders. For the treatment of major dermatological diseases and in the cosmetic industry, topical applications on skin are widely used, thus many efforts in skin research have been aimed at understanding detailed molecular absorption and efficient penetration mechanisms. However, it remains difficult to obtain high-resolution visualization in 3D together with chemical selectivity and quantification in skin research. Nonlinear spectroscopy and microscopy, including two-photon excited fluorescence (TPEF), spontaneous Raman scattering, coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS), are introduced in this work for unambiguous skin morphological identification and topical applied molecules detection. Sev- eral quantitative methods based on nonlinear spectroscopy and microscopy are designed for 3D chemical analysis in reconstructed skin, ex vivo and in vivo on human skin. Furthermore, to adapt to forthcoming clinical applications, an endoscopic design is investigated to bring nonlin- ear imaging in flexible endoscopes
Collins, Matthew John. "Nonlinear Single-photon Generation for Photonic Quantum Technology." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13631.
Повний текст джерелаBarlow, Aaron M. "Spectral Distortions & Enhancements In Coherent Anti-Stokes Raman Scattering Hyperspectroscopy." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32388.
Повний текст джерелаDhayal, Suman. "Nonlinear and Quantum Optics Near Nanoparticles." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822820/.
Повний текст джерелаStegeman, Robert. "Direct Nonlinear Optics Measurements of Raman Gain in Bulk Glasses and Estimates of Fiber Performance." Doctoral diss., University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2899.
Повний текст джерелаPh.D.
Optics and Photonics
Optics
Turner, Fraser. "Multifrequency Raman Generation in the Transient Regime." Thesis, University of Waterloo, 2006. http://hdl.handle.net/10012/2960.
Повний текст джерелаHerrera, Oscar Dario. "Nonlinear Photonics in Waveguides for Telecommunications." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/338755.
Повний текст джерелаVan, Wyck Neal Edward. "MULTIPHOTON SPECTROSCOPY OF THIN FILMS AND SURFACES (NONLINEAR, WAVEGUIDES, INTERFACES)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/291294.
Повний текст джерелаSimonelli, Danielle Marie. "Probing vibrational modes of ammonia with the nonlinear optical technique sum frequency generation /." Thesis, Connect to Dissertations & Theses @ Tufts University, 2000.
Знайти повний текст джерелаAdviser: Mary Jane Shultz. Submitted to the Dept. of Chemistry. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;
Govani, Jayesh R. "Spectroscopic characterizations of organic/inorganic nanocomposites." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
Повний текст джерелаSmith, Brett. "Coherent Anti-Stokes Raman Scattering Miniaturized Microscope." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24281.
Повний текст джерелаAtherton, Kathryn Jane. "Coherent Raman studies of optical nonlinearities in conjugated molecules and polymers." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298790.
Повний текст джерелаKroeger, Felix. "Stimulated Raman Scattering in Semiconductor Nanostructures." Phd thesis, Université Paris Sud - Paris XI, 2010. http://tel.archives-ouvertes.fr/tel-00561176.
Повний текст джерелаOdhner, Johanan. "INVESTIGATIONS OF TEMPORAL RESHAPING DURING FILAMENTARY PROPAGATION WITH APPLICATION TO IMPULSIVE RAMAN SPECTROSCOPY." Diss., Temple University Libraries, 2012. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/196129.
Повний текст джерелаPh.D.
Femtosecond laser filamentation in gaseous media is a new source of broadband, ultrashort radiation that has the potential for application to many fields of research. In this dissertation filamentation is studied with a view to understanding the underlying physics governing the formation and propagation dynamics of filamentation, as well as to developing a method for vibrational spectroscopy based on the filament-induced impulsive vibrational excitation of molecules in the filamentation region. In pursuit of a better understanding of the underlying physical processes driving filamentation, the development of a new method for characterizing high intensity ultrashort laser pulses is presented, wherein two laser beams generate a transient grating in a noble gas, causing the pulse undergoing filamentation to diffract from the grating. Measuring the spectrum as a function of time delay between the filament and probe beams generates a spectrogram that can be inverted to recover the spectral and temporal phase and amplitude of the filamentary pulse. This technique enables measurement of the filamentary pulse in its native environment, offering a window into the pulse dynamics as a function of propagation distance. The intrinsic pulse shortening observed during filamentation leads to the impulsive excitation of molecular vibrations, which can be used to understand the dynamics of filamentation as well. Combined measurements of the longitudinally-resolved filament Raman spectrum, power spectrum, and fluorescence intensity confirm the propagation dynamics inferred from pulse measurements and show that filamentation provides a viable route to impulsive vibrational spectroscopy at remote distances from the laser source. The technique is applied to thermometry in air and in flames, and an analytical expression is derived to describe the short-time dynamics of the rovibrational wave-packet dispersion experienced by diatomic molecules in the wave of the filament. It is found that no energy is initially partitioned into the distribution of rovibrational states during the filamentation process. Filament-assisted impulsive stimulated Raman spectroscopy of more complex systems is also performed, showing that filament-assisted vibrational measurements can be used as an analytical tool for gas phase measurements and has potential for use as a method for standoff detection. Finally, a study of the nonlinear optical mechanisms driving the filamentation process is conducted using spectrally-resolved pump-probe measurements of the transient birefringence of air. Comparison to two proposed theories shows that a newly described effect, ionization grating-induced birefringence, is largely responsible for saturation and sign inversion of the birefringence at 400 nm and 800 nm, while the magnitude of contributions described by a competing theory that relies on negative terms in the power series expansion of the bound electron response remain undetermined.
Temple University--Theses
Rey, Isabella H. "Active slow light in silicon photonic crystals : tunable delay and Raman gain." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3356.
Повний текст джерелаCapitaine, Erwan. "Nouveaux procédés de microspectroscopie Raman cohérent à bande ultralarge." Thesis, Limoges, 2017. http://www.theses.fr/2017LIMO0114/document.
Повний текст джерелаThe spectroscopy technique based on spontanée Raman Stokes scattering is a standard process used in many fields spanning from thermodynamic and medicine, to materials sciences. An inelastic energy exchange permits to determinate the frequency of the molecular vibrations in an object. One can identify the molecules and thus, can characterize the object of study in a label-free way. Nevertheless, this method is afflicted with faults. Beside the presence of fluorecence that can drown the Raman answer, the main drawback is the long exposition time required. In the case of biological sample, this can prohibit the use of spontaneous Raman scattering for microspectroscopy measures: the spectral mapping of microscopic objects. To avoid this problem, new techniques have been developed. It is the case of Coherent anti-Stokes Raman scattering (CARS) spectroscopy. Due to its coherence and its directivity, the anti-Stokes signal has an intensity 105 to 106 times greater than the spontaneous Raman scattering one. The exposition time is then reduced to a tolerable level for biological objects during microspectroscopy measures. Moreover, the anti-Stokes characteristic of the signal prevents the fluorescence contribution. However, a major fault still limits the use of this technique: the nonresonant background. This phenomenon can diminish, even overwhelm the resonant contribution carrying the information. This thesis permitted the development of CARS approaches that allow the reduction of the nonresonant background. To do so, a multiplex CARS (M-CARS) spectroscopy apparatus in a forward configuration has been built. Its abilities are illustrated with spectral measures of mineral, vegetal and biological samples. Based on this system, it has been established an innovative method that can discriminate the resonant signal from the nonresonant one thanks to a static electric field. It has been also been demonstrated the development of a process that has allowed the first M-CARS microspectroscopy measure of a biological sample in a contrapropagative configuration. This setup limits the collect of the signal to the object of study, avoiding the acquisition of the resonant and resonant signals coming from the solvent, responsible for the major part of non resonant background during a CARS measure in a forward configuration
Maugeri, Pearson Thomas Maugeri. "Applications of resonance Raman spectroscopy to the study of bioinorganic macromolecules." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1512093478871388.
Повний текст джерелаTate, Jennifer Lynn. "Intense laser propagation in sapphire." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1083179683.
Повний текст джерелаTitle from first page of PDF file. Document formatted into pages; contains xv, 139 p.; also includes graphics (some col.) Includes bibliographical references (p. 137-139). Available online via OhioLINK's ETD Center
Lombardini, Alberto. "Nonlinear optical endoscopy with micro-structured photonic crystal fibers." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4377.
Повний текст джерелаIn this thesis, we propose the use of a novel type of photonic crystal fiber, the Kagomé lattice hollow core fiber, for the delivery of ultra-short pulses in nonlinear endoscopy. These fibers allow undistorted pulse delivery, over a broad transmission window, with minimum background signal generated in the fiber, thanks to the propagation in a hollow-core. We solved the problem of spatial resolution, by means of a silica micro-bead inserted in the Kagomé fiber large core. We have developed a miniature imaging system, based on a piezo-electric tube scanner, an achromatic micro-lenses assembly and a specifically designed Kagomé double-clad fiber. With this system we were able to image biological tissues, in endoscope modality, activating different contrasts such as TPEF, SHG and CARS, at the distal end of the fiber, a result which finds no equal in current literature. The integration in a portable probe (4.2 mm in diameter) shows the potential of this system for future in-vivo multimodal endoscopy
DeVane, Russell H. "Molecular dynamics and time correlation function theories." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001309.
Повний текст джерелаAbdolghader, Pedram. "Coherent Nonlinear Raman Microscopy and the Applications of Deep Learning & Pattern Recognition Methods to the Extraction of Quantitative Information." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42677.
Повний текст джерелаGhribi, Nabila. "Synthèse, caractérisations structurale et mécanique de nouveaux matériaux tellurites pour des applications en optique non linéaire." Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0003/document.
Повний текст джерелаTellurite materials possess exceptional nonlinear optical properties, with values of the third-order nonlinear optical susceptibility are 10 to 50 times higher than in pure silica, favoring then the efficiency of the nonlinear effects. The origin of these exceptional optical properties is not only associated with the presence of the electronic lone pair, but also with the very strong electronic "delocalization" along Te-O-Te bridges in polymerized chains (TeO2)p. Our experimental researches concerned the following both ternary glass systems: TeO2-TiO2-ZnO (TTZ) and TeO2-GeO2-ZnO (TGZ).The glass formation domains were determined, the thermal stability increases with the increased amount of ZnO, TiO2 and GeO2. The vibrational study carried out using Raman spectroscopy and specular infrared reflectivity, revealed that the increase of the ZnO amount leads to a slight depolymerization of the glass network by breaking chains formed via Te-O-Te bridges. For higher ZnO contents, the latter contributes to a compensation of this break by the formation of new bridges: Te-O-Zn and/or Zn-O-Zn. Mechanical properties were studied at the same time at room and high temperature, in particular around the glass transition temperature. The increase of the ZnO content in TTZ and TGZ glasses increased globally elastic modulus. Finally, the decrease of the third-order nonlinear optical susceptibility with the increased ZnO concentration emphasizes the role of the presence of chains consisted of Te-O-Te bridges in the structure of the tellurite glass
Er-Rhaimini, Salih. "Reconstruction d'image par rétrodiffusion stimulée Raman et amélioration du rendement de conversion." Angers, 1995. http://www.theses.fr/1995ANGE0007.
Повний текст джерелаLouot, Christophe. "Sources de supercontinuum pour la microspectroscopie Raman cohérente large-bande." Thesis, Limoges, 2018. http://www.theses.fr/2018LIMO0015/document.
Повний текст джерелаCoherent Raman microspectroscopy (CARS) is an optical method used to identify molecular bonds in a sample in order to analyze and determine its complete composition. It requires the simultaneous excitation of the sample by two waves (the pump wave and the Stokes wave) in order to induce resonant vibration of the bond to be detected. For multiple bonds analysis (broadband coherent Raman microspectroscopy our Multiplex-CARS), the monochromatic Stokes wave must be replaced by a broadband beam (supercontinuum). The aim of this thesis was to design supercontinuum sources optimized for Multiplex-CARS application, in particular in terms of spectral bandwidth and spectral power density. Supercontinuum generation was investigated in three different optical fibers: (i) a microstructured single mode fiber with a large Yb doped core in which the input beam was re-amplified all along its propagation; (ii) a conventional singlemode fiber pumped in the normal dispersion regime in which spectral broadening was achieved by means of Raman gain saturation; (iii) a conventional graded-index multimode fiber in which the beam spectrally broadened by Raman gain saturation at very high power also experienced spatial self-cleaning by Kerr effect, resulting in a high brillance output beam with an,intensity profile close to that of the fundamental mode. A complete spectrotemporal study is achieved for each of these three sources
Chiarello, Fabrizio. "Analysis and application of nonlinear amplification effects in single-mode optical fibers." Doctoral thesis, Università degli studi di Padova, 2014. http://hdl.handle.net/11577/3423797.
Повний текст джерелаQuesta tesi è focalizzata sulla generazione e sull’elaborazione completamente ottiche di segnali attraverso fenomeni di amplificazione non lineare in fibre ottiche a singolo modo. Tre diversi oscillatori non lineari in fibra ottica sono investigati e dimostrati sperimentalmente. Una pompa ad onda continua per amplificatori Raman in fibra, sviluppata con l’obiettivo di ottenere un alto grado di polarizzazione, sintonizzabilità e soppressione dell’effetto Brillouin, è presentata, discussa e utilizzata al fine di ottenere attrazione di polarizzazione non lineare. Un oscillatore in fibra ottica con sintonia veloce su un’ampia banda basato sugli effetti di amplificazione Raman e di amplificazione parametrica a banda stretta e a banda larga, che sfrutta la tecnica di sintonia mediante dispersione temporale (time-dispersion tuning), è dimostrato e caratterizzato. Ciascuno degli effetti non lineari domina in una diversa regione spettrale, cosicché l’oscillatore raggiunge un intervallo di sintonia di 160 nm. Attraverso lo stesso metodo di sintonia mediante dispersione temporale, un comb ottico in fibra con sintonia veloce, basato sull’effetto di miscelazione a quattro onde a cascata, è ottenuto usando una singola pompa, evitando così i limiti di purezza spettrale e di stabilità di frequenza e di fase dei sistemi a doppia pompa. Infine, il controllo dello stato e del grado di polarizzazione, attraverso l’attrazione di polarizzazione non lineare in amplificatori Raman in fibra ottica standard con birifrangenza aleatoria, è studiato, analizzato e caratterizzato. L’analisi, che include gli effetti di svuotamento della pompa, della rotazione non lineare di polarizzazione e di guadagno Raman ortogonale, mostra che gli amplificatori Raman contro-propaganti sono efficaci nell’attrarre il segnale verso uno stato di polarizzazione predeterminato e imposto dallo stato di polarizzazione di ingresso della pompa. Viene inoltre discussa l’importanza del ruolo dello svuotamento della pompa nell’ottenere la ripolarizzazione del segnale in fibre con dispersione dei modi di polarizzazione moderatamente alta. Le prestazioni e i limiti dell’efficienza di ripolarizzazione vengono determinati portando ad una relazione quantitativa tra il grado di polarizzazione e il guadagno dell’amplificatore Raman, relazione che rappresenta un limite superiore sul massimo grado di polarizzazione raggiungibile.
Küpper, Sebastian [Verfasser], та Sebastian [Akademischer Betreuer] Schlücker. "Vibrational spectroscopic characterization of the photochromic molecule α-dinitrobenzylpyridine bypolarization-resolved linear and nonlinear Raman scattering / Sebastian Küpper ; Betreuer: Sebastian Schlücker". Duisburg, 2021. http://d-nb.info/1230322590/34.
Повний текст джерелаGoel, Nitin Kumar. "Development of "Core-Suction" Technique for Fabrication of Highly Doped Fibers for Optical Amplification and Characterization of Optical Fibers for Raman Amplification." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29302.
Повний текст джерелаPh. D.
Moeferdt, Matthias. "Nonlocal and Nonlinear Properties of Plasmonic Nanostructures Within the Hydrodynamic Drude Model." Doctoral thesis, Humboldt-Universität zu Berlin, 2017. http://dx.doi.org/10.18452/18129.
Повний текст джерелаThis thesis deals with the nonlocal and nonlinear properties of plasmonic nanoparticles, as described by the hydrodynamic model. The hydrodynamic material model represents an extension of the Drude model that contains corrections to the descriptions of the electron plasma. After a thorough derivation of the material model, analytical discussions of nonlocality are presented for the example of a single cylinder. The frequency shifts in the scattering and absorption spectra are quantified and treated asymptotically. Furthermore, by applying a conformal map, the problem of a cylindrical dimer is solved in the electrostatic limit and the modes of the structure are determined. These investigations lay the foundations for numerical investigations which are performed employing the discontinuous Galerkin time domain method. The analytical knowledge of the modes, in conjunction with group theoretical considerations and numerical analysis, enables the formulation of rigorous selection rules for the excitation of modes by linear and nonlinear processes. In further numerical studies, the influence of nonlocality on the field enhancement in dimer structures and double-resonant behavior (a resonance is found at the frequency of the incoming light and at the second harmonic) are investigated.
Kasprzyk, Christina Ridley. "Practical applications of molecular dynamics techniques and time correlation function theories." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001644.
Повний текст джерелаDe, Clermont-Gallerande Jonathan. "Synthèse, structure, et étude mécanique de matériaux tellurites visant des applications en optique non-linéaire." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0082.
Повний текст джерелаThis work aims to comparatively study three systems aimed at nonlinear optical application, TeO2-TiO2-ZnO (TTZ); TeO2-TiO2-Nb2O5 (TTN) and TeO2-GeO2-ZnO (TGZ). The goal is to highlight correlations between structural and mechanical properties of the studied glasses at room temperature but also as a function of temperature, and in particular around the glass transition temperature (Tg). The structural study of the glasses showed that in the TTZ system, the zinc had a coordination and hence a behavior change in the tellurite matrix as a function of the concentration. Those results were correlated to the elastic properties of the glasses, the Young modulus, the shear modulus and the Poisson ratio, who presented nonlinear evolutions as a function of the ZnO concentration. In the TGZ system, in contrary to the TTZ system, these singular evolutions were not highlighted. It was hypothesized that the germanium oxide is preventing the change in comportment of the zinc polyhedra. For the TTN system, no major structural changes were observed as a function of niobium oxide concentration, which was translated with a linear increase of the elastic properties of those glasses. The temperature dependent studies showed that before the glass transition temperature (Tg), the Boson peak frequency (Raman spectroscopy) and the elastic properties evolutions are in accordance with the vitreous network relaxation idea. After Tg, the structural and mechanical evolution showed a transition toward a viscous liquid state. At last, it was possible to evidence a correlation after Tg of the evolution of the Boson peak frequency and the elastic properties, thus allowing a prediction of the mechanical properties thanks to the low frequency vibrational study in tellurite glasses. These information are key parameters needed to help the glass shaping mastery of these types of glasses
van, der Kolk Jarno Nicolaas. "Theory of Image Formation in Non-linear Optical Microscopy." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36650.
Повний текст джерелаSilva, II Gentil Luiz da. "Amplificação de ruído em um meio Kerr com resposta não-linear não-instantânea em pulsos parcialmente coerentes." Universidade Federal de Alagoas, 2014. http://www.repositorio.ufal.br/handle/riufal/1670.
Повний текст джерелаCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
Considerando a não-linearidade não-instantânea do tipo Kerr, a propagacão de um pulso parcialmente coerente é estudado teoricamente através do uso de extensões na equação não linear de Schrödinger. Para isso, levamos em conta um modelo de difusão de fase no pulso parcialmente coerente. Para incorporar o tempo de resposta finito no meio Kerr, utilizamos uma dependência temporal na resposta não linear do meio introduzida na equação não linear de Schrödinger através do modelo de relaxação de Debye. Deduzimos analiticamente também a relação de dispersão e computamos numericamente o espectro de ganho e algumas quantidades estatísticas de segunda ordem relevantes. Neste trabalho realizamos também um estudo detalhado de como estas propriedades estatísticas são influenciadas pelos regimes de dispersão da velocidade de grupo, tanto quanto pelo atraso na resposta não linear do meio em questão. Por fim, enfatizamos as diferentes características para as respostas não lineares rápidas e lentas. Em outra vertente deste trabalho, realizamos estudos teóoricos acerca de tais características estatísticas para o regime de dispersão zero.
MORTATI, LEONARDO MICHAEL. "Coherent Anti-Stokes Raman Scattering, Second Harmonic Generation and Two-Photon Excitation Fluorescence Multimodal Microscope: Realization, Metrological Characterization and Applications in Regenerative Medicine." Doctoral thesis, Politecnico di Torino, 2013. http://hdl.handle.net/11583/2509905.
Повний текст джерелаHuynh, Dan-Nha. "Nonlinear optical phenomena within the discontinuous Galerkin time-domain method." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19396.
Повний текст джерелаThis thesis is concerned with the theoretical description of nonlinear optical phenomena with regards to the (numerical) discontinuous Galerkin time-domain (DGTD) method. It deals with two different material models: the hydrodynamic model for metals and the model for Raman-active dielectrics. In the first part, we review the hydrodynamic model for metals, where we apply a perturbative approach to the model. We use this approach to calculate the second-order nonlinear optical effects of second-harmonic generation and sum-frequency generation using the DGTD method. In this context, we will see how to optimize the second-order response of plasmonic nanoantennas by applying a deliberate tuning scheme for the optical excitations as well as by choosing an intelligent nanoantenna design. In the second part, we examine the material model for Raman-active dielectrics. In particular, we see how to derive the third-order nonlinear response by which one can describe the process of stimulated Raman scattering. We show how to incorporate this third-order response into the DGTD scheme yielding a novel set of auxiliary differential equations. Finally, we demonstrate the workings of the modified numerical scheme.
Derbazi, Maqboula. "Étude des caractéristiques Raman et optique non-linéaire des bronzes de tungstène quadratiques (A6M2M’8O30)." Thesis, Reims, 2013. http://www.theses.fr/2013REIMS041.
Повний текст джерелаRecently, very significant research has been devoted to the study of ferroelectric compounds of tetragonal tungsten bronze (TTB). This thesis deals with the synthesis and characterization of 7 TTB's material with general formula A6M2M'8O30 (A = Sr2+, Ba2+ or Pb2+, M = Ti4+, Zr4+ or HF4+, M '= Nb5+ or Ta5+). These crystalline compounds of large size ~ 100 nm were synthesized in powder form. The experimental Technics: X-ray diffraction, Raman spectroscopy, scanning electron microscopy SEM and TEM and nonlinear optics NLO, allowed us to establish close relationships between structure and physical properties. The nonlinear 2nd and 3rd order optical susceptibility χ(2), χ(3) of all compounds were determined and the resulting values of χ(3) did not show the same characteristics as measures of χ(2) because the THG signal is less dependent on the structure where SHG signal requires a non-centro-symmetric medium. The frequency shift between the vibration modes of structures containing strontium (Sr) and those based on Barium (Ba) has been detailed to identify signatures of these specific compounds. The interpretation of these powders wasn't that easy as these peaks are very delicate but our experimental results clearly show that the positions of the peaks can be modified by the change in cation materials, as long as the crystal lattice is more rigid, more we get discernible Raman modes. This difference is clearly visible where the emission is around 808 cm-1 for the structure Sr, whereas the Br it is centered around 780cm-1. We attribute these Δσ (28cm-1) to the transition of spatial symmetry group from Pba2 to P4bm. Results showed the wide variety of settings in which it is possible to act in order to optimize the compositions for a specific application
Nishizawa, Norihiko, and Toshio Goto. "Widely wavelength-tunable ultrashort pulse generation using polarization maintaining optical fibers." IEEE, 2001. http://hdl.handle.net/2237/6864.
Повний текст джерелаNishizawa, Norihiko, and Toshio Goto. "Compact system of wavelength-tunable femtosecond soliton pulse generation using optical fibers." IEEE, 1999. http://hdl.handle.net/2237/6767.
Повний текст джерелаNishizawa, Norihiko, Ryuji Okamura, and Toshio Goto. "Simultaneous generation of wavelength tunable two-colored femtosecond soliton pulses using optical fibers." IEEE, 1999. http://hdl.handle.net/2237/6771.
Повний текст джерелаNishizawa, Norihiko, Youta Ito та Toshio Goto. "0.78-0.90-μm wavelength-tunable femtosecond soliton pulse generation using photonic crystal fiber". IEEE, 2002. http://hdl.handle.net/2237/6769.
Повний текст джерелаBioud, Fatma Zohra. "Microscopie de mélange à quatre ondes résolue en polarisation pour sonder l’ordre moléculaire dans les milieux biologiques." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4380.
Повний текст джерелаThe capacity to quantify molecular orientational order in tissues is of a great interest since pathologies (skin lesion, neurodegenerative diseases, etc) can induce strong modifications in proteins’ organization. While numerous studies have been undertaken using polarization resolved second order nonlinear optical microscopy which is only specific to non-centrosymmetric organizations, higher order effects have been less explored. Four-wave mixing (FWM) microscopy and its resonant counterpart coherent anti-Stokes Raman scattering (CARS) can be of a great utility as label free diagnosis tools benefiting from less constraining symmetry rules. In this work, we implement incident polarizations tuning in FWM and CARS microscopy to probe molecular order, using a generic method to read-out symmetry information.Fourier analysis of the polarization-resolved FWM/CARS signal processed with an analytical model provides a fast and direct determination of the symmetry orders of the distribution function of the probed molecules. This method does not require a priori knowledge of the organization structure and provides quantitatively its second and fourth order symmetries. We applied this technique on different systems, from crystalline to less organized (multilamellar vesicles and proteins aggregates). We show that this new approach brings additional and more refined information on supra-molecular structures in complex media
Hammani, Kamal. "Ondes scélérates et statistiques extrêmes dans les systèmes optiques fibrés." Phd thesis, Université de Bourgogne, 2011. http://tel.archives-ouvertes.fr/tel-00648126.
Повний текст джерелаSantos, Clenilton Costa dos. "Propriedades ópticas dos vidros Er3+:PbPO4." reponame:Repositório Institucional da UFC, 2010. http://www.repositorio.ufc.br/handle/riufc/9652.
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In this work we employ several techniques to investigate the optical properties of moderately high Er3+-doped lead phosphate (EDLP) glasses. The third-order optical susceptibility, χ3, and dispersion of the linear refractive index, n0(λ), of Er3+:PbPO4 were measured in the wavelength range between 400 and 1940 nm by using the spectrally resolved femtosecond Maker fringes technique. The nonlinear refractive index, n2, obtained from the third-order susceptibility was found to be five times higher than that of silica. For comparison purposes, the Z-scan technique was also employed to obtain the values of n2 of EDLP at several wavelengths, and the values obtained using the two techniques agree to within 15%. From the data obtained by absorption measurements, the Judd-Ofelt theory was employed to calculate the intensity-dependent parameters Ωλ (λ = 2, 4, and 6). We observed that increasing Er3+ content, Ω4 and Ω6 remain constant, while Ω2 decreases. Green, red, and infrared emissions centered at 530, 550, 660, and 1530 nm were observed under excitation at 800 nm. The lifetime of the Er3+: 4I13/2 → 4I15/2 (1530 nm) transition decreases with increasing Er3+ content, reflecting how significant the non-radiative process associated with this transition is. The McCumber theory was used to calculate, from absorption cross-section, the stimulated emission cross-section of the Er3+: 4I13/2 → 4I15/2 transition. A strong re-absorption of the fluorescence at 1530 nm was also observed and analyzed. Finally, we discuss the potential use of Er3+:PbPO4 glasses in photonics devices.
Neste trabalho utilizamos várias técnicas para investigar as propriedades ópticas dos vidros fosfato de chumbo (PbPO4) com concentrações moderadamente altas de íons de érbio (Er3+), EDLP. Medimos a susceptibilidade de terceira ordem, χ3, e a dispersão do índice de refração linear, n0(λ), dos vidros EDLP na região de comprimento de onda entre 400 e 1940 nm, por meio da técnica de Franjas de Maker. A partir do valor de χ3, calculamos o índice de refração não-linear, n2, cujo valor é cerca de cinco vezes maior que o da sílica (SiO2). Também obtivemos os valores de n2 dos vidros EDLP, através da técnica de varredura Z para vários comprimentos de onda. A diferença entre os valores obtidos pelas duas técnicas foi de 15%. Realizamos medidas de absorção óptica, cujos dados foram utilizados para calcular os parâmetros fenomenológicos Ωλ da teoria de Judd-Ofelt. Observamos que Ω4 e Ω6 permanecem praticamente constante com o aumento da concentração de Er3+, ao passo que Ω2 diminui. Excitando as amostras em 800 nm foi possível verificar emissões no verde, vermelho e infravermelho, centradas em 530, 550, 660 e 1530 nm, respectivamente. O tempo de vida da transição 4I13/2 → 4I15/2 (em 1530 nm) do Er3+ diminui com o aumento da concentração de Er3+, refletindo o quão importante é o processo não-radiativo associado a esta transição. A teoria de McCumber foi usada para calcular, a partir da seção de choque de absorção, a seção de choque da emissão estimulada da transição 4I13/2 → 4I15/2 do Er3+. Observamos e analisamos uma forte reabsorção da fluorescência em 1530 nm. Finalmente, discutimos a aplicabilidade dos vidros EDLP em dispositivos fotônicos.
Gąsecka, Paulina. "Polarization resolved nonlinear multimodal microscopy in lipids : from model membranes to myelin in tissues." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4377.
Повний текст джерелаPolarization resolved nonlinear microscopy is a powerful tool to image structural information in biomolecular assemblies. Nonlinear interaction between light and matter lead to complex processes where coherent combinations of optical fields couple to assemblies of molecular transition dipoles. Controlling polarized optical fields and monitoring nonlinear induced signals in a medium can nevertheless bring rich information on molecular orientational organization within the focal spot of a microscope objective. In this PhD thesis we apply this polarization sensitivity to different label-free optical coherent techniques (coherent anti-Stokes Raman scattering (CARS), stimulated Raman scattering (SRS)) and to two-photon fluorescence (2PEF) to retrieve quantitative information on the static molecular distribution shape and orientation of lipids in model membranes and biological membranes such as myelin sheaths in spinal cord tissues. With this technique, we address fundamental questions about lipid packing behavior in membranes, and how it can be affected by other molecules such as cholesterol and the insertion of fluorescent lipid probes. We demonstrate that polarization resolved CARS give access to fine details on lipids arrangement in myelin sheaths, at a sub-diffraction scale. In the context of experimental autoimmune encephalomyelitis disease (EAE) we show, that even at the stage of disruption of the myelin envelope during the demyelination process, lipids multilayers reveal strong capability to preserve their macroscopic self-assembly into highly organized structures, with a degree of disorganization occurring only at the molecular scale
Maurel, Clément. "Verres pour la Photostructuration." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2009. http://tel.archives-ouvertes.fr/tel-00438449.
Повний текст джерелаAl-Obaidi, Rand. "In vitro enamel subsurface lesions : characterization and treatment." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTT017/document.
Повний текст джерелаWhite spot lesion is the subsurface hypomineralization of enamel indicating the 1st stage of dental caries development. Early detection of incipient dental caries before it reaches the stage of cavitation offers an opportunity for effective dental care. The objectives of this study were to strengthen the idiom of minimally invasive treatment. In order to achieve the specified goals; we have identified a modified pH cycling model that can mimic the intraoral conditions leading to white spot lesions formation in a short time. In addition, non-invasive optical techniques, such as confocal Raman microscopy and multiphoton microscopy were used in this study to detect small changes in the enamel chemical composition in vitro.Furthermore, nano-indentation technique was used to detect the changes in the mechanical properties of enamel and relate them to those affecting its chemical composition after caries induction in order to add chemico-mechanical specificity in providing important information about subsurface lesions in enamel. The obtained results demonstrate a great potential for the examined techniques, providing a basis for interesting applications in the clinical diagnosis of various pathological conditions in dentistry. To treatment the incipient carious lesions non-invasively, the effectiveness of GC Tooth Mousse cream and nHA containing-dentifrice "KAREX" in the remineralization of demineralized enamel through localizing amorphous calcium phosphate at tooth surface has been inspected. The study indicated a lack of reliable evidence supporting the efficacy of remineralizing agents in the treatment of white spot lesions. Within the limitations of this study, further laboratory studies together with clinical research are therefore required to increase the available knowledge on this prevalent subject
Pelegati, Vitor Bianchin 1982. "Microscopias ópticas de processos coerentes." [s.n.], 2016. http://repositorio.unicamp.br/jspui/handle/REPOSIP/321828.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
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Resumo: Técnicas de microscopias ópticas são as principais ferramentas capazes de observar células e tecidos biológicos em tempo real e com mínimo dano. Essa área foi revolucionada recentemente através das microscopias confocais de varredura a laser e as microscopias de óptica não linear, naturalmente confocais. Entre os processos não lineares temos, a fluorescência excitada por dois ou mais fótons, geração de segundo harmônico [Second Harmonic Generation - SHG] e terceiro harmônico [Third Harmonic Generation - THG]. SHG e THG são técnicas de óptica não linear coerentes, não necessitam de marcadores exógenos e permitem reconstrução de imagens em três dimensões com resolução espacial subcelular. As técnicas de fluorescência permitem visualizar estruturas específicas no espaço, mas não permitem discriminar as substâncias químicas nas estruturas celulares, e as técnicas de SHG e THG não possuem especificidade química. Espectroscopia Raman possui especificidade química através das propriedades vibracionais das moléculas e pode ser usada como mecanismo de contraste na aquisição de imagens. Comparada com a espectroscopia/microscopia infravermelho, a microscopia Raman traz a informação das vibrações moleculares do infravermelho para o visível, eliminando os problemas da baixa resolução espacial e opacidade das amostras. Entretanto a baixa sensibilidade dessa técnica implica em tempos de aquisição de imagens muito longos, da ordem de horas, inviabilizando acompanhar a dinâmica de processos celulares em tempo real. Como solução para essa baixa sensibilidade do espalhamento Raman espontâneo, surgiu a microscopia por espalhamento Raman Coerente anti-Stokes [Coherent Anti-Stokes Raman Scattering - CARS]. Comparado com Raman espontâneo, a microscopia CARS representa aumento de 4 a 5 ordens de grandeza na sensitividade da técnica, diminuindo os tempos de aquisição ao ponto de viabilizar a aquisição em taxas de vídeos (mais rápido do que 30 quadros por segundo) e estudos em tempo real. Essa tese é dedicada ao estudo experimental e teórico, assim como de algumas aplicações, das técnicas de óptica não linear, com destaque para processos de óptica não linear coerentes. Apresentamos de forma detalhada três sistemas experimentais para a aquisição de imagens de Raman coerente e um sistema integrado com várias técnicas de óptica não linear. Mostramos as primeiras imagens de CARS realizadas no Brasil. Além do CARS convencional, trabalhamos com outra técnica de CARS de ordem mais alta, o CARS cascata [cascade CARS - CCARS], e, no melhor do nosso conhecimento, apresentamos as primeiras imagens internacionais obtidas com essa metodologia. CCARS aumenta o contraste da técnica CARS, diminuindo o fundo não ressonante, um problema que aflige a comunidade científica dedicada ao uso dessa técnica. Além da diminuição do fundo não ressonante, a emissão do CCARS acontece em um comprimento de onda diferente de qualquer outro efeito não linear coerente, significando um acréscimo de complexidade mínimo para sua detecção quando comparado com o CARS. Por último mostramos algumas aplicações realizadas com o sistema experimental desenvolvido para integrar diversas modalidades ópticas em paralelo, especialmente da geração de harmônicos com a fluorescência excitada por dois fótons e suas variantes, como microscopia de tempo de vida de fluorescência (Fluorescence Lifetime Imaging ¿ FLIM)
Abstract: Optical microscopies techniques are the main tools capable of observing cell and biological tissues in real time and with minimum damage. This area have recently been revolutionized by confocal laser scanning microscopies and non-linear microscopies, naturally confocal. Among the non-linear process we have, the two or more photons excited fluorescence, second harmonic generation [SHG] and third harmonic generation [THG]. SHG and THG are coherent nonlinear techniques, they do not require exogenous markers and allow three dimension imaging reconstruction with subcellular resolution. The fluorescence techniques allow visualizing specific structures in space, but do not allow discriminating the chemical substances in cellular structures, SHG and THG techniques do not have chemical specificity. Raman spectroscopy has chemical specificity through the vibrational properties of the molecules and can be used as a contrast mechanism for imaging acquisition. Compared to infrared spectroscopy/microscopy, Raman microscopy brings information about molecular vibration from infrared to visible, eliminating the low resolution and sample opacity problems. However, this technique low sensibility implies in very long imaging acquisition times, order of hours, making it not viable for following cellular process dynamics in real time. As an answer for the spontaneous Raman scattering low sensibility, the coherent anti-Stokes Raman scattering [CARS] emerged. Compared to spontaneous Raman, CARS microscopy presents an increase of 4 to 5 orders of magnitude in the sensitivity of the technique, lowering the acquisition times to the point of making video acquisition (faster than 30 frames per second) and real time studies possible. This thesis is dedicated to the experimental and theoretical study, as well as some applications, of the non-linear techniques, with emphasis on coherent non-linear optical processes. We present in detailed form three experimental systems for the acquisition of coherent Raman images, and a system with the integration of various non-linear techniques. We show the first CARS images acquired in Brazil. In addition to conventional CARS, we worked with other higher order CARS technique, the cascade CARS [CCARS], and, in the best of our knowledge, we present the first international image acquired with this methodology. CCARS increases the contrast from CARS technique, decreasing the non-resonant background, a problem that afflicts the scientific community dedicated to the use of this technique. Besides the decrease of the non-resonant background, the CCARS emission occurs in a different wavelength from any other non-linear coherent effect, meaning a minimum complexity increase for its detection when compared with CARS. Finally we show some applications performed with the experimental system developed to integrate several optical modalities in parallel, especially the generation of harmonics with two photons excitation fluorescence and their variants such as Fluorescence Lifetime Imaging [FLIM]
Doutorado
Física
Doutor em Ciências
830406/2010
CAPES
Vigouroux, Hélène. "Etude de vitrocéramiques optiques pour le doublement de fréquence." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2012. http://tel.archives-ouvertes.fr/tel-00806577.
Повний текст джерелаHage, Charles-Henri. "Sources optiques fibrées pour applications biomédicales." Phd thesis, Université de Bourgogne, 2013. http://tel.archives-ouvertes.fr/tel-00907642.
Повний текст джерелаNeradovskiy, Maxim. "Guides d’ondes dans un cristal de niobate de lithium périodiquement polarisé : fabrication et étude par des techniques de microscopie à sonde locale." Thesis, Nice, 2016. http://www.theses.fr/2016NICE4035/document.
Повний текст джерелаThe investigation of influence of the soft proton exchange (SPE) optical waveguide (WG) creation onperiodically poled lithium niobate (PPLN) has been done. It has been shown that the WG fabricationprocess can induce the formation of needle like nanodomains, which can be responsible for thedegradation of the nonlinear response of the WG created in PPLN crystals. The domain structure (DS)evolution has been studied in congruent lithium niobate (LN) crystals with surface layers modified bythree different proton exchange techniques. The significant decrease of the nucleation threshold fieldand qualitative change of domain rays nucleation and growth have been revealed. The formation of abroad domain boundary and dendrite domain structure as a result of nanodomains merging in front ofthe moving rays has been demonstrated. The formation of DS in LN with SPE by irradiation of coveredby electron resist polar surface of LN has been investigated. Formation of domains with arbitrary shapesas a result of discrete switching has been revealed. Finally, it has been demonstrated that electron beamirradiation of lithium niobate crystals with surface resist layer can produce high quality periodical domainpatterns after channel waveguide fabrication. Nonlinear characterizations show that the conversionefficiencies and the phase matching spectra conform to theoretical predictions, indicating that thiscombination presents a great interest for device fabrication. Second harmonic generation withnormalized nonlinear conversion efficiency up to 48%/(W cm2) has been achieved in such waveguides
Santos, Clenilton Costa dos. "Propriedades Ãpticas dos vidros Er3+:PbPO4." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=4874.
Повний текст джерелаNeste trabalho utilizamos vÃrias tÃcnicas para investigar as propriedades Ãpticas dos vidros fosfato de chumbo (PbPO4) com concentraÃÃes moderadamente altas de Ãons de Ãrbio (Er3+), EDLP. Medimos a susceptibilidade de terceira ordem, χ3, e a dispersÃo do Ãndice de refraÃÃo linear, n0(λ), dos vidros EDLP na regiÃo de comprimento de onda entre 400 e 1940 nm, por meio da tÃcnica de Franjas de Maker. A partir do valor de χ3, calculamos o Ãndice de refraÃÃo nÃo-linear, n2, cujo valor à cerca de cinco vezes maior que o da sÃlica (SiO2). TambÃm obtivemos os valores de n2 dos vidros EDLP, atravÃs da tÃcnica de varredura Z para vÃrios comprimentos de onda. A diferenÃa entre os valores obtidos pelas duas tÃcnicas foi de 15%. Realizamos medidas de absorÃÃo Ãptica, cujos dados foram utilizados para calcular os parÃmetros fenomenolÃgicos Ωλ da teoria de Judd-Ofelt. Observamos que Ω4 e Ω6 permanecem praticamente constante com o aumento da concentraÃÃo de Er3+, ao passo que Ω2 diminui. Excitando as amostras em 800 nm foi possÃvel verificar emissÃes no verde, vermelho e infravermelho, centradas em 530, 550, 660 e 1530 nm, respectivamente. O tempo de vida da transiÃÃo 4I13/2 → 4I15/2 (em 1530 nm) do Er3+ diminui com o aumento da concentraÃÃo de Er3+, refletindo o quÃo importante à o processo nÃo-radiativo associado a esta transiÃÃo. A teoria de McCumber foi usada para calcular, a partir da seÃÃo de choque de absorÃÃo, a seÃÃo de choque da emissÃo estimulada da transiÃÃo 4I13/2 → 4I15/2 do Er3+. Observamos e analisamos uma forte reabsorÃÃo da fluorescÃncia em 1530 nm. Finalmente, discutimos a aplicabilidade dos vidros EDLP em dispositivos fotÃnicos.
In this work we employ several techniques to investigate the optical properties of moderately high Er3+-doped lead phosphate (EDLP) glasses. The third-order optical susceptibility, χ3, and dispersion of the linear refractive index, n0(λ), of Er3+:PbPO4 were measured in the wavelength range between 400 and 1940 nm by using the spectrally resolved femtosecond Maker fringes technique. The nonlinear refractive index, n2, obtained from the third-order susceptibility was found to be five times higher than that of silica. For comparison purposes, the Z-scan technique was also employed to obtain the values of n2 of EDLP at several wavelengths, and the values obtained using the two techniques agree to within 15%. From the data obtained by absorption measurements, the Judd-Ofelt theory was employed to calculate the intensity-dependent parameters Ωλ (λ = 2, 4, and 6). We observed that increasing Er3+ content, Ω4 and Ω6 remain constant, while Ω2 decreases. Green, red, and infrared emissions centered at 530, 550, 660, and 1530 nm were observed under excitation at 800 nm. The lifetime of the Er3+: 4I13/2 → 4I15/2 (1530 nm) transition decreases with increasing Er3+ content, reflecting how significant the non-radiative process associated with this transition is. The McCumber theory was used to calculate, from absorption cross-section, the stimulated emission cross-section of the Er3+: 4I13/2 → 4I15/2 transition. A strong re-absorption of the fluorescence at 1530 nm was also observed and analyzed. Finally, we discuss the potential use of Er3+:PbPO4 glasses in photonics devices.