Relevant bibliographies by topics / Optical spatial modulation

Academic literature on the topic 'Optical spatial modulation'

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Published: 6 September 2023

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Journal articles on the topic "Optical spatial modulation"

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Chao Liu, Chao Liu, Di Wang Di Wang, Lixiao Yao Lixiao Yao, Lei Li Lei Li, and Qionghua Wang Qionghua Wang. "Optical attenuator based on phase modulation of a spatial light modulator." Chinese Optics Letters 13, no. 8 (2015): 082301–82304. http://dx.doi.org/10.3788/col201513.082301.

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Mesleh, Raed, Hany Elgala, and Harald Haas. "Optical Spatial Modulation." Journal of Optical Communications and Networking 3, no. 3 (February 28, 2011): 234. http://dx.doi.org/10.1364/jocn.3.000234.

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Cogalan, T., H. Haas, and E. Panayirci. "Optical spatial modulation design." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, no. 2169 (March 2, 2020): 20190195. http://dx.doi.org/10.1098/rsta.2019.0195.

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Visible light communication (VLC) systems are inherently signal-to-noise ratio (SNR) limited due to link budget constraints. One favourable method to overcome this limitation is to focus on the pre-log factors of the channel capacity. Multiple-input multiple-output (MIMO) techniques are therefore a promising avenue of research. However, inter-channel interference in MIMO limits the achievable capacity. Spatial modulation (SM) avoids this limitation. Furthermore, the performance of MIMO systems in VLC is limited by the similarities among spatial channels. This limitation becomes particularly severe in intensity modulation/direct detection (IM/DD) systems because of the lack of phase information. The motivation of this paper is to propose a system that results in a multi-channel transmission system that enables reliable multi-user optical MIMO SM transmission without the need for a precoder, power allocation algorithm or additional optics at the receiver. A general bit error performance model for the SM system is developed for an arbitrary number of light-emitting diodes (LEDs) in conjunction with pulse amplitude modulation. Based on this model, an LED array structure is designed to result in spatially separated multiple channels by manipulating the transmitter geometry. This article is part of the theme issue ‘Optical wireless communication’.
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Yesilkaya, Anil, Rui Bian, Iman Tavakkolnia, and Harald Haas. "OFDM-Based Optical Spatial Modulation." IEEE Journal of Selected Topics in Signal Processing 13, no. 6 (October 2019): 1433–44. http://dx.doi.org/10.1109/jstsp.2019.2920577.

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Pelekanos, N. T., B. Deveaud, J. M. Gérard, H. Haas, U. Strauss, W. W. Rühle, J. Hebling, and J. Kuhl. "All-optical spatial light modulator with megahertz modulation rates." Optics Letters 20, no. 20 (October 15, 1995): 2099. http://dx.doi.org/10.1364/ol.20.002099.

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Zhang Yue, 张悦, 王惠琴 Wang Huiqin, 曹明华 Cao Minghua, and 黄瑞 Huang Rui. "Enhanced Optical Spatial Modulation in Wireless Optical Communication." Acta Optica Sinica 40, no. 3 (2020): 0306001. http://dx.doi.org/10.3788/aos202040.0306001.

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Michinel, Humberto, Raúl de la Fuente, and Jesús Liñares. "Temporal modulation of spatial optical solitons." Applied Optics 33, no. 16 (June 1, 1994): 3384. http://dx.doi.org/10.1364/ao.33.003384.

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Anderson, Betty Lise, and Lawrence J. Pelz. "Spatial-coherence modulation for optical interconnections." Applied Optics 34, no. 32 (November 10, 1995): 7443. http://dx.doi.org/10.1364/ao.34.007443.

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Goncharov, D. S., N. N. Evtikhiev, V. V. Krasnov, N. M. Ponomarev, and R. S. Starikov. "The influence of additional phase modulation of an amplitude liquid crystal STLM on the image recognition characteristics in the invariant optical digital correlator." Computer Optics 43, no. 2 (April 2019): 200–208. http://dx.doi.org/10.18287/2412-6179-2019-43-2-200-208.

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We present the results of measurements of additional phase modulation characteristics of a serial amplitude liquid crystal spatial light modulator HoloEye LC 2002. It is found in which way the phase shift of the liquid crystal spatial light modulator depends on the applied signal. The mathematical simulation of the performance of an invariant diffractive optical-digital correlator based on a liquid crystal spatial light modulator with the amplitude-dependent phase shift is carried out using previously measured data. The correlation filters used in the work are an optimal tradeoff maximum average correlation height filter and a minimum noise and correlation energy optical correlation filter. A method for correlation filters optimization was proposed to compensate for the recognition error caused by the presence of the additional phase modulation. In some cases, the optimization allows one not only to compensate for the recognition error, but also to reduce it.
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Ochi, Seiga, Kouta Ozaki, Kohei Noda, Heeyoung Lee, Kentaro Nakamura, and Yosuke Mizuno. "Guideline for improving spatial resolution in direct-modulation Brillouin optical correlation-domain reflectometry." Japanese Journal of Applied Physics 62, no. 8 (August 1, 2023): 088001. http://dx.doi.org/10.35848/1347-4065/aceb44.

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Abstract We investigate the spatial resolution of direct-modulation Brillouin optical correlation-domain reflectometry (BOCDR) by exploring the impact of modulation amplitude and frequency. Our findings reveal that optimal resolution improvement is attained through an initial increase in modulation amplitude, followed by modulation frequency adjustment. These insights provide a basic guideline for enhancing the spatial resolution in direct-modulation BOCDR.
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Dissertations / Theses on the topic "Optical spatial modulation"

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Luo, Haitao. "Snapshot Imaging Polarimeters Using Spatial Modulation." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/193905.

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The recent demonstration of a novel snapshot imaging polarimeter using the fringe modulation technique shows a promise in building a compact and moving-parts-free device. As just demonstrated in principle, this technique has not been adequately studied. In the effort of advancing this technique, we build a complete theory framework that can address the key issues regarding the polarization aberrations caused by using the functional elements. With this model, we can have the necessary knowledge in designing, analyzing and optimizing the systems. Also, we propose a broader technique that uses arbitrary modulation instead of sinusoidal fringes, which can give us more engineering freedom and can be the solution of achromatizing the system. In the hardware aspect, several important progresses are made. We extend the polarimeter technique from visible to middle wavelength infrared by using the yttrium vanadate crystals. Also, we incorporate a Savart Plate polarimter into a fundus camera to measure the human eye's retinal retardance, useful information for glaucoma diagnosis. Thirdly, a world-smallest imaging polarimeter is proposed and demonstrated, which may open many applications in security, remote sensing and bioscience.
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Yeatman, Eric Morgan. "Surface plasmon applications : microscopy and spatial light modulation." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47722.

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Kelly, Thu-Lan. "Liquid crystal spatial light modulators as computer controlled optical elements /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phk298.pdf.

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Abelard, Clément. "Micro modulateur spatial de lumière transmissif pour modulation de phase et d’amplitude." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT092/document.

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Le LETI possède un savoir-faire permettant de réaliser des micro modulateurs spatiaux de lumière (Spatial Light Modulators, SLMs) réalisés en technologie microélectronique sur silicium, ayant des très grandes résolutions et de très petits pas de pixels. Le LETI souhaite utiliser une technologie LCD particulière (la technologie IPS) dont d’une part les performances électro-optiques dans le domaine des micro-écrans ne sont pas connues mais d’autre part permet de garder des coûts réduits et de réduire le nombre d’étapes de fabrication. L’objectif de cette thèse est d’évaluer sur la base de simulations puis de réalisations techniques, les performances d’un micro-SLM IPS utilisé en modulation de phase et d’amplitude.Les recherches effectuées au cours de cette thèse portent sur 4 axes d’études. Le premier axe consiste à la recherche et à l’essai d’un logiciel spécifique (LCDMaster) permettant de simuler des cellules à cristaux liquides ainsi que des électrodes flottantes. Le second axe consiste à étudier en fonction du design du pixel et des différents modes d’alignements des cristaux liquides (Homogène, vertical et twisté) avec un pilotage de type IPS, les performances en modulation de phase. Les meilleurs résultats sont obtenus pour un alignement vertical fournissant un déphasage de 2 Pi. De plus, les performances d’un dispositif d’optique adaptative intégrant le SLM étudié ont été investiguées. Le troisième axe d’étude, consiste avec le même logiciel à investiguer sur les performances d’un SLM à cristaux liquide avec un pilotage de type IPS utilisant un alignement homogène en modulation d’amplitude (étude statique et dynamique). Cette étude permet également d’étudier les possibilités de diminution du temps de réponse de la cellule. Cette étude a aboutie à deux designs de SLM. Le premier design avec deux niveaux d’électrodes séparés par un isolant permettant de reproduire un effet type « cage de faraday ». La seconde a permis de diminuer de manière drastique le temps de réponse. Le quatrième axe de recherche consiste à tester des prototypes basés sur ces deux designs pour vérifier les performances obtenues en simulation grâce à un banc de caractérisation électro-optique. Des résultats concordants ont étés obtenus et de nouveaux types de SLM à pilotage IPS proposant un temps de rafraichissement rapides se rapprochant de l’état de l’art ont donc pu être désignés et caractérisés
LETI possesses an expertise allowing to realize Spatial Light Modulators (SLMs) made in microelectronic technology on silicon, having very high resolutions and very small pixel steps. LETI wishes to use a specific LCD technology (IPS technology), on the one hand the electro-optical performances in the field of micro-display had to be investigated but on the other hand allows to keep costs down and reduce the number of manufacturing steps. The objective of this thesis is to evaluate on the basis of simulations and technical achievements, the performance of a micro-SLM IPS used in phase modulation and amplitude.Our investigations have been carried out on four major areas of study. The first axis is the search and testing of a specific software (LCDMaster) to simulate liquid crystal cells and floating electrodes. The second axis according to different designs of pixel and the different liquid crystal alignment modes (Homogeneous, vertical and twisted) with an IPS type control, to investigate the performances in modulation phase. The best results were obtained for a vertical alignment providing a phase shift of 2π. In addition, the performance of an adaptive optics device integrating the studied SLM has been investigated. The third axis of study focused on the performance investigation of a liquid crystal SLM with an IPS-type control using a homogeneous alignment in amplitude modulation (static and dynamic study). This study also makes it possible to study the possibilities of reducing the response time of the cell. It resulted in two SLM designs. The first design with two levels of electrodes separated by an insulator to reproduce a Faraday type effect. The second has drastically reduced the response time. The fourth area of research consists in testing prototypes based on these two designs to validate the performances obtained in simulation. Concordant results have been obtained and new types of IPS-controlled SLMs with state-of-the-art refreshing times have thus been designated and characterized
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Mustonen, Juvi K. "Spatial contrast sensitivity and external noise: applications to optical and neural modulation transfer functions." Thesis, Aston University, 1995. http://publications.aston.ac.uk/14551/.

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The thesis will show how to equalise the effect of quantal noise across spatial frequencies by keeping the retinal flux (If-2) constant. In addition, quantal noise is used to study the effect of grating area and spatial frequency on contrast sensitivity resulting in the extension of the new contrast detection model describing the human contrast detection system as a simple image processor. According to the model the human contrast detection system comprises low-pass filtering due to ocular optics, addition of light dependent noise at the event of quantal absorption, high-pass filtering due to the neural visual pathways, addition of internal neural noise, after which detection takes place by a local matched filter, whose sampling efficiency decreases as grating area is increased. Furthermore, this work will demonstrate how to extract both the optical and neural modulation transfer functions of the human eye. The neural transfer function is found to be proportional to spatial frequency up to the local cut-off frequency at eccentricities of 0 - 37 deg across the visual field. The optical transfer function of the human eye is proposed to be more affected by the Stiles-Crawford -effect than generally assumed in the literature. Similarly, this work questions the prevailing ideas about the factors limiting peripheral vision by showing that peripheral optical acts as a low-pass filter in normal viewing conditions, and therefore the effect of peripheral optics is worse than generally assumed.
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Gardner, Mark Charles. "Phase object pattern recognition by optical correlation using a liquid crystal display for spatial phase modulation." Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409700.

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Blancon, Jean-Christophe. "Optical absorption and electronic properties of individual carbon nanotubes." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10164/document.

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Au cours de ce travail de thèse à caractère expérimental, nous nous sommes attachés à mesurer les spectres absolus de section efficace d’absorption de nanotubes de carbone individuels placés dans différents environnements. Pour ce faire, nous avons développé un dispositif expérimental basé sur la technique de spectroscopie à modulation spatiale qui permet d’accéder de manière directe à la section efficace d’absorption de nano-objets individuels. Cette méthode ne requière aucun a priori sur les propriétés des nanotubes, et très important nous affranchit des effets d’ensemble. Ainsi, nous avons pu étudier les propriétés d’absorption de nanotubes individuels simple et double parois dans les environnements suivants : suspendus librement, agrégés en petit fagot, et déposés sur substrat. Plus précisément, l’évolution de l’absorption excitonique des nanotubes est analysée en fonction des paramètres structuraux (diamètre, nombre de parois, chiralité) et de l’environnement de ces derniers. Un autre aspect de cette thèse a pour objet l’analyse des propriétés de transport électronique des nanotubes de carbone soumis à des pressions hydrostatiques de gaz de l’ordre du gigapascal, avec la possibilité d’accéder au régime des basses températures. Ici, nous nous sommes concentrés sur l’étude de transistors à effet de champ composés de petits fagots de nanotubes de carbone contactés à leurs extrémités par des électrodes en palladium. Dans ce cadre, nous avons notamment réalisé la première observation de l’effet de blocage de Coulomb sous pression. Au final, ce travail de thèse a permis d’analyser les propriétés optiques et électroniques intrinsèques aux nanotubes de carbone et leur évolution sous l’effet de différents environnements (écrantage diélectrique, dopage chimique, contrainte mécanique et pression hydrostatique). Ce travail a pu être réalisé grâce au développement de nouvelles techniques permettant de sonder ces propriétés au niveau du nanotube individuel
In this dissertation, we report on the experimental investigation of the optical properties of single- and double-wall carbon nanotubes. Despite numerous studies performed using photoluminescence or Raman and Rayleigh scattering, knowledge of their optical response is still partial. In particular direct quantitative measurement of their absorption cross-section has not been achieved yet. Using spatial modulation spectroscopy we have determined, over a broad optical spectral range, the spectrum and amplitude of the absorption cross-section of identified individual single- and double-wall carbon nanotubes. These quantitative measurements permit the determination of the oscillator strength of the different excitonic resonances. Furthermore, investigation of the same nanotube, either a single-wall or double-wall nanotube, freestanding or deposited on a substrate shows large broadening with increase of oscillator strength of the excitonic resonances, as well as stark weakening of polarization dependent antenna effects, due to nanotube-substrate interaction. Similar study on nanotube bundles and double-wall nanotubes demonstrate the importance of inter-tube and inter-wall exciton coupling effects which seem to be of different nature in these two types of sample. The second part of this thesis studies electrical transport in carbon nanotube bundles under high pressure condition and low temperature. The behavior of nanotubebased field-effect transistors has been investigated, in the classical and Coulomb blockade regime, under gas-pressure up to 0.9 GPa. Overall, this dissertation communicates on the quantitative analysis of the absorption and electronic properties of carbon nanotubes and how they are influenced by various environmental effects such as dielectric screening, stress induced strain, hydrostatic pressure, or chemical doping. The novelty of this work is to address these issues at the single nanotube level
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Rye, Jan-Michael. "Spatial Modulation Spectroscopy Of Single Nano-Objects In A Liquid Environment For Biosensing Applications." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1053/document.

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Le développement de méthodes rapides, précises et ultra-sensibles pour la détection d'analytes cibles en solution est crucial pour la recherche et les applications potentielles en médecine ou biologie moléculaire. Une approche très prometteuse consiste à développer des nano-capteurs à partir de nano-objets métalliques (NOM) qui présentent une résonance d'extinction dans leur réponse optique. Cette résonance nommée résonance de plasmon de surface localisée (RPSL) peut être ajustée spectralement en jouant sur la nature, la morphologie et l'environnement du NOM. Mesurer des modifications sur la RPSL de nano-objets individuels en présence d'analytes cibles doit permettre de s'affranchir des effets de moyennes dans les mesures d'ensemble. De plus, cela ouvre la voie vers le développement d'échantillons micrométriques pour des tests multicibles sans étiquette (« label-free »).Dans ce travail on a développé un nouveau dispositif expérimental basé sur la technique de spectroscopie à modulation spatiale (SMS) permettant de sonder la réponse optique de NOM individuels en milieu liquide. En parallèle des méthodes de synthèse ont été mises au point pour obtenir des échantillons sondes stables permettant des mesures sur NOM unique, en particulier sur des bipyramides d'or qui présentent de nombreuses qualités intrinsèques faisant d'elles de bonnes candidates pour le « bio-sensing ».Des mesures ont été réalisées dans des environnements d'indice variable et les changements détectés sont en bon accord avec les simulations théoriques. De plus, de nombreuses études ont été réalisées pour comprendre l'influence des nombreux paramètres agissant sur la réponse optique des systèmes étudiés
Advances in the development of rapid, accurate and highly sensitive methods for detecting target analytes in solution will provide crucial tools for research and applications in medicine and molecular biology. One of the currently most promising approaches is the development of nanosensors based on the localized surface plasmon resonance (LSPR) of noble metal nano-objects (MNOs), which is an optical response that depends on their size, shape, composition and local environment. The ability to measure the modification of the reponse of a single MNO in the presence of a target analyte would allow each object to act as an independent probe with increased sensitivity as the signal would be isolated from the averaging effects of ensemble measurements. Furthermore it would allow the development of micrometric, functionalized multiprobe samples for multitarget label-free assays.In this work, a novel experimental setup based on the spatial modulation spectroscopy (SMS) technique has been developed to measure the optical response of individual nano-objects in a liquid environment. In parallel, a new technique has also been developed to elaborate stable probes for measurements with the new setup, with a focus on gold bipyramids due to numerous qualities that make them excellent candidates for biosensing probes. The setup has been used to measure the response of individual objects in environments of different real refractive indices and the detected changes have been shown to be in good agreement with theoretical calculations. Numerical studies have also been performed to investigate the influence on the optical response of numerous factors encountered in the studied systems
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Mmbaga, Paul Fahamuel. "Study, analysis and application of optical OFDM, Single Carrier (SC) and MIMO in Intensity Modulation Direct Detection (IM/DD)." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/15952.

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With the rapid growth of wireless data demands and saturation of radio frequency (RF) capacity, visible light communication (VLC) has become a promising candidate to complement conventional RF communication, especially for indoor short range applications. However the performance of the system depends on the propagation and type of system used. An optical Orthogonal Frequency Division Multiplexing (O-OFDM) together with multiple input multiple output (MIMO) in different scenario and modulation techniques are studied in the thesis. A novel optical wireless communication (OWC) multi-cell system with narrow field of view (FOV) is studied. In this system the intensity modulated beam from four light sources are used for communication. The system allows beams to be concentrated in specific areas of the room to serve multiple mobile devices with low interference and hence increase system capacity. The performance of asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM), direct current biased optical OFDM (DCO-OFDM) and single carrier (SC) modulation are then compared in this system considering single user and multiusers scenarios. The performance of the multi-cell is compared with single cell with wide FOV. It is shown that the capacity for multi-cell system increases with the number of users to 4 times the single user capacity. Also the findings show that multi-cell system with narrow beams can outperform a single wide beam system in terms of coverage area and hence average throughput of about 2.7 times the single wide beam system capacity. One of the impairments in line of sight (LOS) OWC systems is coverage which degrades the performance. A mobile receiver with angular diversity detectors in MIMO channels is studied. The objective is to improve the rank of the channel matrix and hence system throughput. Repetition coding (RC), spatial multiplexing (SMP) and spatial modulation (SM) concepts are used to evaluate throughput across multiple locations in a small room scenario. A novel adaptive spatial modulation (ASM) which is capable of combating channel rank deficiency is devised. Since the receiver is mobile, the channel gains are low in some locations of the room due to the lack of LOS paths between transmitters and receivers. To combat the situation adaptive modulation and per antenna rate control (PARC) is employed to maximise spectral efficiency. The throughputs for fixed transmitters and receivers are compared with the oriented/inclined detectors for different cases. Angular diversity detectors offer a better throughput improvement than the state of the art vertical detectors, for example in ASM angular diversity receiver gives throughput of about 1.6 times that of vertical detectors. Also in SMP the angular detectors offer throughput about 1.4 times that of vertical detectors. SMP gives the best performance compared to RC, SM and ASM, for example SMP gives throughput about 2.5 times that of RC in both vertical detectors and angular diversity receivers. Again SMP gives throughput about 6 times that of SM in both vertical detectors and angular diversity receivers. Also SMP provides throughput about 2 times that of ASM in both vertical detectors and angular diversity receivers. ASM exhibit improvement in throughput about average factor of 3.5 times SM performance in both vertical detectors and angular diversity detectors. As the performance of the system may be jeopardized by obstructions, specular and diffuse reflection models for indoor OWC systems using a mobile receiver with angular diversity detectors in MIMO channels are considered. The target is to improve the MIMO throughput compared to vertically oriented detectors by exploiting reflections from different reflecting surfaces in the room. The throughput across multiple locations in the small room by using RC, SMP and SM approaches is again evaluated. The results for LOS only channels against LOS with specular or diffuse reflection conditions, for both vertical and angular oriented receivers are then compared. The results show that exploiting specular and diffuse reflections provide significant improvements in link performance. For example the reflection coefficient (α) of 0.9 and the antenna separation of 0.6 m, RC diffuse model shows throughput improvement of about 1.8 times that of LOS for both vertical detectors and angular diversity receivers. SM diffuse model shows throughput improvement of about 3 times that of LOS for both vertical detectors and angular diversity receivers. ASM diffuse model shows throughput improvement of about 2 times that of LOS for both vertical detectors and angular diversity receivers. SMP diffuse model shows throughput improvement of about 1.5 times that of LOS for both vertical detectors and angular diversity receiver.
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Rouxel, Romain. "Ultrafast thermo-optical dynamics of single plasmonic nanoparticles." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSE1306.

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Les changements de propriétés dynamiques de nanodisques d'or individuels supportés sur un substrat de saphir ont été étudiés sur des échelles de temps allant de la femtoseconde à la nanoseconde par la combinaison des techniques de spectroscopie par modulation spatiale et de spectroscopie optique résolue en temps. Les nanodisques sont mis hors-équilibre par l’absorption d’une impulsion optique de pompe, et leur relaxation est sondée optiquement par la mesure de la transmission d’une seconde impulsion. Dans la première partie de ce travail, la dynamique du transfert de chaleur du nano-objet au substrat a été mesurée de manière systématique pour des nanodisques de différentes dimensions. Les refroidissements observés sont quasi-exponentiels, avec une constante de temps dépendant principalement de l'épaisseur du disque, et faiblement de son diamètre. La comparaison des signaux expérimentaux avec les résultats de calculs par éléments finis indique que la dynamique de refroidissement est principalement limitée par la résistance thermique de Kapitza à l'interface nanodisque-substrat, dont la valeur a pu être extraite. En outre, la sensibilité des mesures pompe-sonde aux changements de température du nano-objet a été déterminée expérimentalement en fonction de la longueur d'onde de la sonde, ses valeurs et variations spectrales présentant un bon accord quantitatif avec les résultats d'un modèle thermo-optique par éléments finis. La deuxième partie de cette thèse se concentre sur les phénomènes ultra-rapides consécutifs à la photo-excitation d’un nano-objet, qui conduisent à sa thermalisation interne par des échanges d’énergie électron-électron et électron-phonon. En particulier, la sensibilité à ces phénomènes de l’extinction optique de nanodisques individuels a été étudiée expérimentalement en fonction de la longueur d'onde de la sonde. Ces mesures ont été comparées aux résultats d'un modèle numérique complet basé notamment sur la résolution de l'équation de Boltzmann et prenant également en compte l'effet du chauffage du réseau ionique, conduisant à un bon accord quantitatif. Une version simplifiée de ce modèle a également permis de mettre en évidence les rôles respectifs de l’évolution des températures des électrons et du réseau, clarifiant ainsi grandement les dépendances temporelle et spectrale des signaux résolus en temps
The ultrafast dynamics of individual gold nanodisks supported on a sapphire substrate occurring at femtosecond to nanosecond timescales have been investigated using the combination of single-particle spatial modulation and time-resolved optical spectroscopies. Nanodisks are excited out of equilibrium by the absorption of an optical pump pulse, and their relaxation is optically probed by measuring the transmission of a second probe pulse. In the first part of this work, the dynamics of heat transfer from the nano-object to the substrate have been systematically measured for nanodisks of various dimensions. Quasi-exponential cooling kinetics were found, with a time constant mainly depending on the disk thickness and weakly on its diameter. Comparison of experimental signals with the results of finite-element calculations indicates that the cooling dynamics are primarily limited by the Kapitza thermal boundary resistance at the nanodisk-substrate interface, whose value could be extracted. Additionally, the sensitivity of pump-probe measurements to transient temperature changes in the nano-object was experimentally determined as a function of the probe wavelength, its values and spectral variations presenting a good quantitative agreement with the results of a thermo-optical finite-element model. The second part of this thesis focuses on the ultrafast phenomena immediately following the nano-object photo-excitation, leading to its internal thermalization through electron-electron and electron-phonon energy exchanges. In particular, the sensitivity of the optical extinction of individual nanodisks to these phenomena has been experimentally investigated as a function of the probe wavelength. These measurements were compared with the results of a complete numerical model based notably on the resolution of the Boltzmann equation and also taking into account the effect of lattice heating, yielding a good quantitative agreement. A simplified version of this model also allowed to highlight the respective roles of the temperature evolutions of the electrons and of the ionic lattice, greatly clarifying the temporal and spectral dependences of the measured time-resolved signals
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Books on the topic "Optical spatial modulation"

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Uzi, Efron, ed. Spatial light modulator technology: Materials, devices, and applications. New York: Marcel Dekker, 1995.

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Salgals, Toms. Development and Assessment of a Spectrally Efficient Hybrid Optical Communication Systems. RTU Press, 2022. http://dx.doi.org/10.7250/9789934228056.

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Thesis describes the wavelength division multiplexed fiber optic communication systems, i.e., assessment of the development of PON and DCI. Experimentally evaluate the application of spectrally efficient multi-level pulse amplitude modulation formats to increase the performance of PON, DCI and RoF solutions for 5G and beyond implementation. Application of SDM technology for the implementation of a spectrally and spatial efficient wavelength division multiplexed FOTS is evaluated. Spectrally efficient next-generation optical system for the transmission of millimeter-wave radio signals over fiber for cellular mobile communications and new hybrid fiber optic transmission system architecture capable of broadband Internet data transmission and radio signal transmission over single optical fiber was developed. Implementation of a novel type of transmission with a novel WGMR-based Kerr-OFC multi-wave light source are shown and presented for first time.
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Efron, Uzi. Spatial Light Modulator Technology (Optical Engineering). CRC, 1994.

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4

Penn. Liquid Crystals and Spatial Light Modulator Materials (Proceedings of Spie--The International Society for Optical E). SPIE-International Society for Optical Engine, 1986.

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Book chapters on the topic "Optical spatial modulation"

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Bhowal, Anirban, and Rakhesh Singh Kshetrimayum. "Advanced Spatial Modulation for Underwater Optical Wireless Communication." In Advanced Spatial Modulation Systems, 141–90. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9960-6_5.

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Nitta, Kouichi, Takashi Kamigiku, Takeshi Nakajima, and Osamu Matoba. "Parallel Processing for Prime Factorization with Spatial Amplitude Modulation in Optics." In Optical Supercomputing, 7–14. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-38250-5_2.

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Hayasaki, Yoshio, and Satoshi Hasegawa. "Spatial Beam Shaping with a Liquid-Crystal Spatial Light Modulator for Surface Micro- and Nanoprocessing." In Springer Series in Optical Sciences, 533–79. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-14752-4_15.

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Improso, Wynn Dunn Gil D., Giovanni A. Tapang, and Caesar A. Saloma. "Suppression of Zeroth-Order Diffraction in Phase-Only Spatial Light Modulator." In Springer Series in Optical Sciences, 1–30. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-12692-6_1.

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Manzanera, S., P. M. Prieto, J. Salort, E. J. Fernández, and P. Artal. "Adaptive Optics to Simulate Vision with a Liquid Crystal Spatial Light Modulator." In Adaptive Optics for Industry and Medicine, 317–24. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/3-540-28867-8_32.

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Lemieux, Robert P., Liviu Dinescu, and Kenneth E. Maly. "Optical Switching of a Ferroelectric Liquid Crystal Spatial Light Modulator Using Chiral Thioindigo Dopants." In ACS Symposium Series, 227–38. Washington, DC: American Chemical Society, 2001. http://dx.doi.org/10.1021/bk-2001-0798.ch017.

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Sultana, Sadia, Ferdous Mohammed Shahriar, and Mohammad Khalad Hasan. "Chip-to-chip Free-space Optical Interconnection Using Liquid-crystal-over-silicon Spatial light modulator." In Technological Developments in Networking, Education and Automation, 507–10. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-9151-2_88.

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Agour, Mostafa, Claas Falldorf, and Christoph von Kopylow. "Complementary Filtering Approach to Enhance the Optical Reconstruction of Holograms from a Spatial Light Modulator." In Fringe 2009, 1–6. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-03051-2_34.

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Hazu, K., T. Tanigawa, N. Nakagawa, Y. Sakakibara, Sh b. Fang, T. Sekikawa, and M. Yamashita. "Two Dimension Spatial Light Modulator with an Over-Two-Octave Bandwidth for High-Powered Monocycle Optical Pulses." In Springer Series in Chemical Physics, 899–901. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-95946-5_291.

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Khan, Muhammed Fuzail. "Internal Photonic Modulation of Various Spatial Polarization Modes Using Digital Laser Transmission Across Fiber Optic Channels." In Lecture Notes in Electrical Engineering, 12–26. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-8595-7_2.

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Conference papers on the topic "Optical spatial modulation"

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Pezzaniti, J. Larry, Elizabeth A. Sornsin, Russell A. Chipman, and B. Mansoorian. "Characterization of the optical quality and modulating properties of a PLZT modulator through Mueller matrix imaging polarimetry." In Spatial Light Modulators and Applications. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/slma.1995.lthb3.

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The Physics Department at the University of Alabama in Huntsville (UAH) in collaboration with the Electrical and Computer Engineering Department of University of California, San Diego (UCSD) has applied Mueller matrix imaging polarimetry[1] to quantifying the polarization modulating properties of PLZT spatial light modulators. The purpose of this study was to evaluate the optical quality of a wire-bonded transmissive PLZT (9/65/35) modulator array, the uniformity of modulation across pixels, and the cross-talk between adjacent pixels.
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Florence, James M. "Image Correlation Using a Deformable Mirror Device as a Programmable Fourier Plane Filter." In Spatial Light Modulators and Applications. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/slma.1988.pdp1.

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The deformable mirror device (DMD) light modulator is a monolithic silicon integrated device that operates by the electro-static deflection of miniature mirror elements.1 There are a variety of different mirror element structures and array sizes currently under development for different light modulating applications. For optical image processing applications, a pixel structure capable of phase modulation is of particular interest. A phase modulator can be used in the Fourier plane of a coherent optical system to implement phase-flattening filters for image correlation or other operations where manipulation of Fourier transform phase is required.
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Fainman, Y. "Recent Advances in Applications of Photorefractive Devices for Optical Computing." In Spatial Light Modulators and Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/slma.1990.mb1.

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Spatial light modulating devices have received much attention recently, primarily for the numerous functions they can perform in parallel optical computing. Various physical principles have been employed in the construction of these spatial light modulators1-3 (SLMs) e.g., liquid crystal light valves, microchannel SLMs, Si-PLZT SLMs, quantum well devices, ferroelectric liquid crystal devices, membrane SLMs, and photorefractive devices. Conventional optically addressed 2-D spatial light modulators (OSLM) are based on the detection of the spatial light distribution of a writing wave and the generation of an electric field image that is used to drive a device that modulates the reading wave. Most of the conventional OSLMs are fabricated by integrating photosensing devices with electro-optic modulators. Similarly, the devices based on photorefractive effect utilize the photoconductivity and electro-optic effect of the material. In photorefractive devices, the spatial intensity distribution of the interference between input waves generates a spatial charge distribution that is held by the self-induced space charge electric field; via the electro-optic effect, this space charge field modulates the refractive index in the volume of the material; which in turn affects the wave propagation and the spatial light distribution at the output. While the photorefractive devices and the conventional OSLMs based on electro-optic modulators are similar in the physical mechanisms they employ (i.e., photosensitivity and electro-optic effect), they differ in their modulation mechanisms. For example, conventional OSLMs may use amplitude modulation via polarization or phase modulation in thin electro-optic media; photorefractive SLMs, on the other hand, rely on the nonlinear interactions (i.e., mixing) of waves in the volume of thin or thick photorefractive material.
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Hunt, J. H., and R. B. Holmes. "Spatial Light Modulation at Photon-Counting Light Levels." In Spatial Light Modulators and Applications. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/slma.1995.ltha4.

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Recently, there has been a great deal of interest in the use of avalanche photodiodes (APD) for spatial light modulation.1,2,3 We report improved performance of our all-optical spatial light modulation with an avalanche photodiode. Modulation is performed with the APD operating as an asymmetric Fizeau interferometer with refractive index modulated by optically-initiated, avalanche-induced heating. Modulation of 80 % is achieved with optically optimized APDs. We demonstrate multiple-pixel operation, as well as free-carrier induced modulation.
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Bennion, I., M. J. Goodwin, C. J. Groves-Kirkby, and A. D. Parsons. "64 Element Hybrid PLZT/Silicon Spatial Light Modulator Array." In Optical Computing. Washington, D.C.: Optica Publishing Group, 1989. http://dx.doi.org/10.1364/optcomp.1989.me1.

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The high-throughput spatial light modulator (SLM) is a key component in an expanding range of optical signal processing applications and VLSI interconnect scenarios. With the continuing trend towards overall system integration, a number of approaches have been pursued in recent years, with the common aim of developing a silicon-compatible modulator system, preferably addressed via a fully integrated silicon back-plane with a 1:1 mapping between drive circuits and modulation elements. Potentially viable technologies investigated hitherto include liquid crystals [1,2,3], magneto optic materials.[4] and micromechanical devices fabricated in silicon itself [5], all of which exhibit relatively limited modulation rates.
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Parfenov, A., K. Harada, M. Itoh, T. Yatagai, and N. Tamaoki. "Electrooptical spatial light arrayed modulator for free-space and waveguide optical data processing." In Spatial Light Modulators. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/slmo.1997.swd.3.

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Electro-optical polymers obtain very attractive features - such as large electro-optical coefficient, possibility to make waveguides, photoconductivity and photorefractivity, as well as very important technological features - ability to stay under photolithography, material engineering to change some physical or chemical properties which do not influence others parameters and simple film technology. Some weaknesses such as the lack of stability under chemical environment could be avoided by encapsulating with other more stable polymers. With all these features in mind we suggest new structures of Spatial Light Arrayed Modulator (SLAM) for modulation of light beams with 2-dimentional access to the each of pixels in it.
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Harvey, Phil, and Sadik Esener. "Self-Tuned Fabry Perot Light Modulator Array." In Spatial Light Modulators. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/slmo.1997.swc.2.

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We are developing a surface-normal light modulator structure that has the potential to achieve low voltage (<5V) and high frequency operation (>few hundred MHz) operation with good contrast ratio (>20:1) and spatially uniform response over a large area (~1”x1”). The technique is based upon Fabry-Perot structures using electro-optic phase modulation materials. Conventional modulators of this type are well known for their sensitivity to optical path differences (resulting from, e.g., cavity thickness variations, cavity index variations, or uncollimated optical beams). Our approach is to replace the input mirror with an in-situ recorded holographic mirror, resulting in what we call a Self-Tuned Fabry Perot (STFP) modulator. We have previously demonstrated the STFP concept with a large (2.5mm x 2.5mm) single element modulator and collimated light. Here we present out latest experimental results of a 9x9 modulator array which uses a focusing lenslet array.
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Horsky, T. N., G. J. Genetti, D. M. O’Mara, C. M. Schiller, and C. Warde. "Electron Beam-Addressed Membrane Light Modulator." In Spatial Light Modulators and Applications. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/slma.1990.wa2.

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First introduced by Preston1 in 1968, deformable mirror SLMs incorporating a highly reflective membrane as the light modulating element have generated interest within the applied optics community as good candidates for both adaptive optics and projection display applications.2-4 These SLMs exhibit very fast response times, can be read out with high optical efficiency, and in principle can incorporate a very large number of resolution elements. Since a deformable mirror SLM is essentially a two-dimensional phase modulating element with large phase dynamic range, it is well-suited to adaptive optics applications such as wavefront correction and beam steering. With appropriate pixelization of the membrane surface, intensity modulation may be accomplished via the Schlieren readout schemes employed by projection display systems such as the Eidophor5 (G.E.) and the γ-Ruticon6 (Xerox). The construction of a membrane light modulator (MLM) is such that a membrane is deposited over an array of wells with an addressable electrode at the bottom of each well. Thus, the well and its electrode define an individual pixel. The membrane is coated with a thin electrode material held at a static potential. A pixel is activated by establishing a potential difference between the well electrode and the membrane electrode, causing the membrane to deform into the well region in response to electrostatic forces. Hence, the pixel driving voltage induces a local phase modulation on the readout wavefront reflected by the membrane mirror surface.
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Zhao, Yinan, Chen Chen, Lin Zeng, and Min Liu. "Fully Generalized Optical Spatial Modulation." In 2023 Opto-Electronics and Communications Conference (OECC). IEEE, 2023. http://dx.doi.org/10.1109/oecc56963.2023.10209943.

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Estes, Michael, and Garret Moddel. "Surface Normal Optical Modulation in Thin Film Silicon: Is It feasible?" In Spatial Light Modulators and Applications. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/slma.1995.ltuc9.

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Unlike direct band gap materials such as GaAs, which exhibit very sharp and strong absorption at the band edge, indirect gap crystalline silicon has relatively weak band edge absorption and hence weak band edge nonlinearities[1]. Even hydrogenated amorphous silicon (a-Si:H) with its quasi-direct bandgap shows only moderate electro-optic modulation at its nominally 1.7 eV band edge[2, 3] due to disorder-induced tail states. In addition, both a-Si:H and c-Si are centrosymmetric materials so that there are no χ(2) optical nonlinearities.
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Reports on the topic "Optical spatial modulation"

1

Li, Yao. Massively Parallel Spatial Light Modulation-Based Optical Signal Processing. Fort Belvoir, VA: Defense Technical Information Center, March 1993. http://dx.doi.org/10.21236/ada264846.

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