Tesis sobre el tema "Optical fibre link"
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TAMPELLINI, ANNA. "Coherent fibre-optic link: applications in Time and Frequency metrology, Geodesy, Radio Astronomy and Seismology". Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2742522.
Texto completoBARBIERI, PIERO. "High-Accuracy Optical Frequency Metrology: traceability at the 1E-17 level". Doctoral thesis, Politecnico di Torino, 2020. http://hdl.handle.net/11583/2827704.
Texto completoBenameur, Sarah. "La mise en œuvre, dans une chaîne de transmission optique, à haut débit, de filtres optiques à longueur d’onde centrale réglable". Thesis, Limoges, 2015. http://www.theses.fr/2015LIMO0044/document.
Texto completoThis study relates to the field of optical transmission systems fibers and more particularly the impact of different filtering techniques (optical) on the performance of optical transmission systems (metro access). Reception, these systems have a narrow filter, which filters the signal without having to deal with the noise in the link. It is generally considered that the narrowness of the receiving filter is indispensable for the proper functioning of a link without repeaters, and the sensitivity of the link is even greater than the width of the filter is close to the theoretical limit that is the spectrum width of the transmitted signal. The use of such filters has constraints. Firstly, the filters have steep slopes, and are expensive. On the other hand, a shift of the wavelength of the emitter length is always possible, so that most of the receivers comprise receiving filters whose wavelength is locked to the wavelength of the transmitter. For a transmission system with wavelength multiplexing, wherein plural different wavelengths may be used, this allows to increase the capacity of information transmitted, but however poses real constraints such that crosstalk between channels. The channels are multiplexed in the same fiber and filtered upon receipt by an optical filter which is used both in the channels and demultiplexing a possible optical filter in the spectrum of the considered channel. The optical filter has variable parameters: shape, bandwidth, and center wavelength, then the channel will be filtered and analyzed by the receiver. It includes a photodiode followed by an electrical filter of the form of the filter function of order Bessel type 5. Quality information will be evaluated by the bit error rate BER.In this thesis we propose to analyze the impact of the fundamental parameters of the filters on the performance of an optical system
Kelbler, Petr. "Optická linka pro přenos vysokofrekvenčního signálu". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316435.
Texto completoWang, Shih-Cheng. "Alignment tolerant, single-fiber, bi-directional link". Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/13841.
Texto completoMarra, Giuseppe. "Transfer of optical frequency combs over optical fibre links". Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/350220/.
Texto completoSaleh, Walid. "In-line optical fiber holography". Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41970.
Texto completoDetwiler, Thomas Frederick. "Continuous phase modulation for high speed fiber-optic links". Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42867.
Texto completoBouhamri, Zine-Abidine. "Transmission multi-standards sur lien optique bas-coût". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00957588.
Texto completoMa, Xiaobing. "Analysis and simulation of the Kerr effect in long haul in-line fiber amplifier transmission systems". Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-171804/.
Texto completoCorbeil, Sacha Emmanuel. "Polarization mode dispersion in cascaded optical fibre communication links". Thesis, University of Ottawa (Canada), 1998. http://hdl.handle.net/10393/4425.
Texto completoCorbeil, Sacha E. "Polarization mode dispersion in cascaded optical fibre communication links". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq36676.pdf.
Texto completoTian, Zhaobing. "In-line optical fiber interferometric refractive index sensors". Thesis, Kingston, Ont. : [s.n.], 2008. http://hdl.handle.net/1974/1358.
Texto completoWu, Yang. "Optical heterodyned radio-over-fiber link design using electroabsorption & electrooptic modulators /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3123659.
Texto completoChapman, David. "Dark signalling and code division multiple access in an optical fibre LAN with a bus topology". Thesis, Open University, 2002. http://oro.open.ac.uk/22800/.
Texto completoTegegne, Zerihun. "SiGe/Si Microwave Photonic devices and Interconnects towards Silicon-based full Optical Links". Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1070/document.
Texto completoWith the recent explosive growth of connected objects, for example in Home Area Networks, the wireless and optical communication technologies see more opportunity to merge with low cost MicroWave Photonic (MWP) technologies. Millimeter frequency band from 57GHz to 67GHz is used to accommodate the very high speed wireless data communication requirements. However, the coverage distance of these wireless systems is limited to few meters (10m). The propagation is then limiting to a single room mostly, due to both the high propagation attenuation of signals in this frequency range and to the wall absorption and reflections. Therefore, an infrastructure is needed to lead the signal to the distributed antennas configuration through MWP technology. Moreover, MWP technology has recently extended to address a considerable number of novel applications including 5G mobile communication, biomedical analysis, Datacom, optical signal processing and for interconnection in vehicles and airplanes. Many of these application areas also demand high speed, bandwidth and dynamic range at the same time they require devices that are small, light and low power consuming. Furthermore, implementation cost is a key consideration for the deployment of such MWP systems in home environment and various integrated MWP application.This PhD deals with very cheap, Bipolar or BiCMOS integrated SiGe/Si MWP devices such as SiGe HPTs, Si LEDs and SiGe LEDs, and focused on the combined integration of mm wave and optoelectronic devices for various applications involving short wavelength links (750nm to 950nm).This research focused on the study of the following points:The better understanding of vertical and lateral illuminated SiGe phototransistors designed in a 80 GHz Telefunken GmbH SiGe HBT technology. We draw conclusions on the optimal performances of the phototransistor. The light sensitive Si substrate and two-dimensional carrier flow effects on SiGe phototransistor performance are investigated. This study helps to derive design rules to improve frequency behavior of the HPT for the targeted applications.For future intra /inter chip hybrid interconnections, we design polymer based low loss microwave transmission lines and optical waveguides on low resistive silicon substrate. It is a step to envisage further Silicon based platforms where SiGe HPT could be integrated at ultra-low cost and high performances with other structures such high-speed VCSEL to build up a complete optical transceiver on a Silicon optical interposer. The polymer is used as dielectric interface between the line and the substrate for electrical interconnections and to design the core and cladding of the optical waveguide.The design, fabrication and characterization of the first on-chip microwave photonic links at mid infrared wavelength (0.65-0.85μm) based on 80 GHz Telefunken GmbH SiGe HBT technological processes. The full optical link combines Silicon Avalanche based Light Emitting Devices (Si Av LEDs), silicon nitride based waveguides and SiGe HPT. Such device could permit hosting microfluidic systems, on chip data communication and bio-chemical analysis applications
Dimopoulos, C. "Study of dynamic phenomena in WDM optical fibre links and networks based on EDFAs". Thesis, University of Essex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327071.
Texto completoXu, Yanping. "Multi-Parameter Sensing Based On In-Line Mach-Zehnder Interferometer". Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26010.
Texto completoMlejnek, Zbyněk. "Simulace monitoringu optické trasy". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218743.
Texto completoSun, Qing. "Novel optical launch techniques for high-speed extended-reach multimode-fibre datacommunication links". Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608530.
Texto completoGeddis, Demetris Lemarcus. "Single fiber bi-directional OE links using 3D stacked thin film emitters and detectors". Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180141/unrestricted/geddis%5Fdemetris%5Fl%5F200312%5Fphd.pdf.
Texto completoLamilla, Rubio Erick Abraham 1985. "Transmitindo padrões de frequência atômicos por redes de fibras ópticas=Transmitting atomic frequency standards in optical fiber networks". [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/276939.
Texto completoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-08-28T03:18:42Z (GMT). No. of bitstreams: 1 LamillaRubio_ErickAbraham_M.pdf: 5773132 bytes, checksum: 33effe596fdd1deb74be96f588fc6150 (MD5) Previous issue date: 2015
Resumo: Neste trabalho foi feito um estudo experimental da transmissão de padrões de frequência atómicos através de uma rede de fibra optica. Até onde sabemos este tipo de transmissão foi realizada pela primeira vez no Brasil. Utilizamos uma conexão de fibra óptica entre o Instituto de Física Gleb Wataghin (IFGW) e a Faculdade de Engenharia Elétrica e Computação (FEEC) da UNICAMP, correspondendo a uma distância de aproximadamente 2 km, e um comprimento total de fibra de 18 km. Frequências de RF derivadas de padrões de frequência de Rubídio e de um receptor GPS foram transmitidas e caracterizadas através de medidas de frequência, particularmente por gráficos de variância de Allan, e medidas da fase
Abstract: In this experimental work, transmission of an atomic frequency standard through an optical fiber network has been implemented for first time in Brazil, to the best of our knowledge. We have used a fiber link between the Institute of Physics (IFGW) and the Department of Electrical Engineering inside the campus of the University of Campinas (UNICAMP) corresponding to 18 km fiber link (2km between buildings). Radio frequencies derived from a Rubidium standard and a GPS (Global Position system) receiver has been transmitted and characterized via phase and frequency measurements, particularly trough Allan deviation plots and phase measurements
Mestrado
Física
Mestre em Física
2013/15492-2
FAPESP
Abbood, Abdul Nasser Abdul Jabbar. "Optimised radio over fibre links for next generation radio access networks". Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/17019.
Texto completoShin, Dong-Soo. "High-efficiency optical modulation and detection for analog fiber-optic links /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2001. http://wwwlib.umi.com/cr/ucsd/fullcit?p3029644.
Texto completoPredehl, Katharina. "A 920 km optical fiber link for frequency metrology at the 19th decimal place". Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-150213.
Texto completoLiu, Zhansheng. "Characterization of RSOA modulators in radio over fiber links". Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13985.
Texto completoIn this work physical and behavioral models for a bulk Reflective Semiconductor Optical Amplifier (RSOA) modulator in Radio over Fiber (RoF) links are proposed. The transmission performance of the RSOA modulator is predicted under broadband signal drive. At first, the simplified physical model for the RSOA modulator in RoF links is proposed, which is based on the rate equation and traveling-wave equations with several assumptions. The model is implemented with the Symbolically Defined Devices (SDD) in Advanced Design System (ADS) and validated with experimental results. Detailed analysis regarding optical gain, harmonic and intermodulation distortions, and transmission performance is performed. The distribution of the carrier and Amplified Spontaneous Emission (ASE) is also demonstrated. Behavioral modeling of the RSOA modulator is to enable us to investigate the nonlinear distortion of the RSOA modulator from another perspective in system level. The Amplitude-to-Amplitude Conversion (AM-AM) and Amplitude-to-Phase Conversion (AM-PM) distortions of the RSOA modulator are demonstrated based on an Artificial Neural Network (ANN) and a generalized polynomial model. Another behavioral model based on Xparameters was obtained from the physical model. Compensation of the nonlinearity of the RSOA modulator is carried out based on a memory polynomial model. The nonlinear distortion of the RSOA modulator is reduced successfully. The improvement of the 3rd order intermodulation distortion is up to 17 dB. The Error Vector Magnitude (EVM) is improved from 6.1% to 2.0%. In the last part of this work, the performance of Fibre Optic Networks for Distributed and Extendible Heterogeneous Radio Architectures and Service Provisioning (FUTON) systems, which is the four-channel virtual Multiple Input Multiple Output (MIMO), is predicted by using the developed physical model. Based on Subcarrier Multiplexing (SCM) techniques, four-channel signals with 100 MHz bandwidth per channel are generated and used to drive the RSOA modulator. The transmission performance of the RSOA modulator under the broadband multi channels is depicted with the figure of merit, EVM under di erent adrature Amplitude Modulation (QAM) level of 64 and 254 for various number of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers of 64, 512, 1024 and 2048.
Nesta tese são propostos modelos físicos e comportamentais para o amplificador óptico semicondutor reflectivo (RSOA), tendo como objectivo a avaliação do seu desempenho quando utilizado como modulador em ligações de rádio sobre fibra (RoF). Os modelos propostos são capazes de prever o comportamento do dispositivo quando utilizado com sinais de banda larga bem como quando estimulado por sinais de elevada potência. Inicialmente propõe-se um modelo físico simplificado para o RSOA baseado nas equações de taxa e nas equações de propagação electromagnética. A implementação do modelo utiliza o ADS (Advanced Design Systems) e o bloco designado por dispositivo definido simbolicamente (SDD) para descrever as equações de taxa, assim como a propagação de fotões ao longo da cavidade. O modelo permite uma análise detalhada do ganho óptico, distorções harmônicas, intermodulação e seu desempenho de transmissão com portadoras RF modeladas. Foram também considerados modelos comportamentais. Um modelo baseado em rede neural artificial (ANN) e um modelo polinomial generalizado para banda base foram considerados tendo os parâmetros respectivos sido extraídos utilizando, para o efeito, dados obtidos experimentalmente. São demonstradas a característica da distorção resultante da conversão amplitude - amplitude (AM-AM) e conversão da fase - amplitude (AM-PM) no modulador RSOA. Um modelo baseado em parametros X, obtidos a partir do modelo físico, foi também analisado. Compensação da não-linearidade do modulador RSOA é realizada com base num modelo polinomial com memória. Demonstra-se que a distorção não linear do modulador RSOA pode ser compensada com sucesso. Com a compensação obtem-se uma redução de 17 dB da distorção introduzida pelos produtos de intermodulação de terceira ordem. O EVM (Error Vector Magnitude) apresenta uma melhoria de 6,1% para 2,0%. Na última parte deste trabalho considera-se uma configuração que representa a ligação ascendente por fibra de um sistema de antenas remoto a uma estação central de processamento. Com esta configuração pretendese demonstrar a possibilidade de implementação de uma tecnologia MIMO, suportada num sistema RoF. Baseado numa técnica de multiplexação subportadora (SCM), os sinais de quatro canais com largura de banda de 100 MHz por canal são multiplexados e utilizados para modelar o ganho do RSOA. O desempenho deste link óptico é caracterizado para modulações OFDM considerando diferentes números de sub-portadoras por símbolo (64, 512 , 1024 e 2048) assim como o formato QAM imposto sobre cada sub-portadora.
Kelkar, Anish S. "Dynamic range of analog fiber optic links used in microcellular mobile radio applications". Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/41988.
Texto completoThe dynamic range is limited by the noise and the nonlinear distortion introduced by the
fiber link. The main sources of nonlinear distortion are threshold clipping, gain saturation
of the laser, and the combination of laser chirp and fiber dispersion. We have analytically
modeled these nonlinearities and used these models to understand the dependence of the
nonlinear distortion on the physical parameters of the laser diode and the fiber and also on
the modulation index per channel and the number of channels. The performance of the 1S-
19 AMPS signals and the IS-54IDMA signals in the presence of fiber link noise is also
discussed. Finally, the dynamic range of the fiber link for both AMPS and IDMA signals
has been analyzed. The dynamic range of the fiber link is limited by the threshold clipping
nonlinearity. It is also highly dependent on the number of mobile signals that are being
communicated over the fiber link.
Master of Science
Bachim, Brent L. "DESIGN AND TESTING OF A SIMPLE OPTICAL FIBER TELEMETRY LINK FOR USE IN RUGGED ENVIRONMENTS". International Foundation for Telemetering, 1998. http://hdl.handle.net/10150/607358.
Texto completoThe design and testing of an optical fiber telemetry link for use in rugged environments is described. Several potential applications for this cost effective telemetry link built from readily available components are given. The results of testing the simple telemetry link for vibrations up to 20g and temperatures up to 150° C are reported.
CLIVATI, CECILIA. "Realization of a phase-coherent optical fiber link for the comparison of remote atomic clocks". Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2555736.
Texto completoGiovannini, Andrea. "Countermeasures to Rayleigh Backscattering in optical fiber links for Radio Astronomy applications". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
Buscar texto completoDroste, Stefan [Verfasser]. "Optical frequency transfer via telecommunication fiber links for metrological applications / Stefan Droste". Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2014. http://d-nb.info/1065397607/34.
Texto completoSisto, Marco Michele. "Optical distribution links for OFDM-based wireless networks". Doctoral thesis, Université Laval, 2009. http://hdl.handle.net/20.500.11794/20776.
Texto completoGill, Malvinder Singh. "Optically powered electrical resonant circuit incorporating reactive sensors and having fibre optic links". Thesis, Brunel University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363284.
Texto completoKaur, Namneet. "Transfert de temps à longue distance utilisant des liaisons à fibre optique et comparaison croisée avec des méthodes par satelliteires". Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEO002/document.
Texto completoTime and frequency references are widely distributed over communications and computer networks, for a variety of scientific and industrial applications. Driven by a demand for improved performance, a number of new methods for time and frequency transfer over optical fiber-based networks have been developed in recent years. In this thesis our objective is to develop a scalable network time and frequency transfer approach, providing multi-user dissemination, compatible with large telecommunication networks and competitive with GNSS-based time distribution. Therefore we are concerned with methods for use in packet-based networks, like the Network Time Protocol (NTP) and Precision Timing Protocol (PTP). We also concentrate on “unidirectional” links, where the forward and backward signals between network nodes propagate over separate fibers, not within the same fiber (“bidirectional” links).In particular we use a method called White Rabbit PTP (WR). This is a novel technology developed at CERN, based on PTP while using Synchronous Ethernet and other techniques to achieve high performance. It demonstrates sub-nanosecond time stability and synchronization of arrays of instruments over 10 km scale networks. We are particularly interested in extending this method for large scale distribution of references at regional or national level, over links of up to 1000 km.We first study extensively the default performances and limitations of White Rabbit network equipment, in particular the White Rabbit switch. We make various improvements to its operation: on the locking of the grandmaster switch to the external reference, thus improving its short-term stability by more than an order of magnitude; optimizing the locking bandwidth of the slave switch; and increasing the PTP messaging rate between master and slave switches.We then study medium and long-distance WR links. We construct a 100 km, unidirectional link using fiber spools in the laboratory. We discover that the short-term performance is limited by chromatic dispersion in the fiber, while the long-term performance is degraded by the influence of temperature variations on the fiber. To limit the effect of chromatic dispersion for long-haul links, we propose the use of a cascaded approach. We realise a national scale, cascaded, 500 km link, again utilizing fiber spools. We use Dense Wavelength Division Multiplexing methods to construct this link by mutliple passages through shorter spools. We achieve a frequency transfer stability of 2 × 10−12 at one second of integration time and 5 × 10−15 at one day, limited by thermal noise in the long term. We achieve a time stability of 5 ps at one second of integration time, decreasing to a minimum of 1.2 ps at 20 seconds and remaining below one nanosecond for longer averaging times. These performances are similar in the short term, and two orders of magnitude better in the long term, than good quality GPS receivers. We expect thermal fluctuations and therefore the effect of fiber thermal noise to be suppressed by a factor of approximately five for installations in the field.Finally we make preliminary investigations of time calibration of WR links. The main challenge here is to measure the optical length asymmetry between the two fibers used for signal transfer in the forward and backward directions. We demonstrate a fiber swapping technique, using a mid range, suburban White Rabbit link over dark fiber. We then describe and test a new variational method for calibration, involving a differential measurement method based on operating two WR links at different wavelengths over the same optical fiber link.In conclusion, we demonstrate high performance, long haul White Rabbit links for time and frequency dissemination to multiple users. With the level of frequency transfer performance achieved, White Rabbit PTP provides a competitive and scalable technique for comparing industrial atomic clocks at regional and national scales
Haas, Bryan Michael. "LIinearized optically phase-modulatd fiber optic links for microwave signal transport". College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9124.
Texto completoThesis research directed by :Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Kemme, Shanalyn Adair 1961. "Modal noise in multimode fiber-optic links using vertical cavity surface emitting lasers". Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282717.
Texto completoCastillo, Díaz Jorge Andrés. "Study on the limiting factors of a coherent optical fiber link, applied to phase transfer for femtosecond synchronization". Tesis, Universidad de Chile, 2013. http://www.repositorio.uchile.cl/handle/2250/115599.
Texto completoEl Gran Conjunto Milimétrico / submilimétrico de Atacama (ALMA) es el observatorio astronómico más grande jamás construido. Se encuentra ubicado en el Llano de Chajnantor, a una altitud de 5.000 metros sobre el nivel del mar en el norte de Chile. Se compone de un conjunto de 66 antenas distribuidas en un área de 15 km de diámetro y que opera entre 35 y 950 GHz, Estas antenas están interconectados en un interferómetro capaz de detectar fuentes de señales débiles procedentes del espacio más profundo y producir imágenes con una resolución angular mejor que el telescopio espacial Hubble. Para lograr este rendimiento de las antenas se tiene que registrar las señales procedentes del cielo con un error de tiempo más pequeño que 38 fs. Esta sincronización se realiza mediante señales ópticas transmitidas desde un edificio central utilizando una red de fibra óptica del tipo usado en telecomunicaciones. El sistema de transmisión se ve afectado por perturbaciones externas tales como la vibración, y oscilaciones térmicas. Estas perturbaciones además de cambiar directamente la longitud de la fibra, afectan el estado de polarización de la luz que viaja a través de ella. Este cambio de longitud puede ser neutralizado aplicando un esquema de corrección de longitud de línea que utiliza estiradores de fibra. Sin embargo, el cambio de polarización no es fácil de compensar, y su interacción con la dispersión de modo de polarización (PMD) , produce una variación de fase adicional. Con el fin de minimizar este efecto, ALMA especificó valores de PMD muy bajos para todos los equipos que se ubican en el camino óptico de la señal que transmite la referencia de fase. Puesto que el sistema de corrección de longitud de línea utiliza estiradores mecánicos, se debe poner especial atención en alinear el estado de polarización de la señal que entra al estirador de fibra con su punto óptimo. Solamente encontrando este punto se puede minimizar el cambio de polarización que se produce al estirar la fibra ubicada en el interior del estirador mecánico. Este trabajo presenta un algoritmo innovador y eficiente para encontrar el eje óptimo de los estiradores de fibra utilizados en ALMA. Este algoritmo se desarrolló durante la realización de este trabajo, y permite una identificación rápida y precisa del eje óptimo que minimiza el cambio de polarización, comparado con el método original, este algoritmo reduce en un 70% el tiempo promedio de calibración y reduce en un 50% el error de calibración residual. También se hace una revisión de los sistemas de transferencia de referencia de tiempo utilizados en ALMA. Explicando los desafíos que enfrentan y las soluciones tecnológicas implementadas para supéralos. A continuación, se presenta el efecto del PMD, mostrando diferentes técnicas de medición y su compensación. Además este trabajo presenta un conjunto de mediciones de PMD realizadas sobre fotomezcladores, estiradores de fibra, e instalaciones de fibra en el Arreglo Muy Grande (o Very Large Array, administrado por NRAO) y en ALMA. The Atacama Large Millimeter/Submillimeter Array (ALMA) is the largest astronomical observatory ever built. It is located on the Chajnantor plateau, at an altitude of 5000 meters above the sea level in northern Chile. It consists of an array of 66 antennas spread in a 15 km diameter area and operating between 35 and 950 GHz. These antennas are interconnected in an interferometer capable to detect weakest signal sources coming from the deepest space and produce images with an angular resolution better than the Hubble space telescope. To achieve this performance the antennas need to record the signals coming from the sky with a time error smaller than 38 fs; this synchronization is made using optical signals transmitted from a central building via a telecommunication grade fiber optic network. This transmission system is affected by some external perturbations like vibrations and thermal cycles. These perturbations, besides directly changing the length of the fiber, affect the polarization state of the light traveling across it. The length change can be neutralized implementing a line length correction scheme that uses fiber stretchers, but the polarization change is not easy to compensate, and its interaction with the polarization mode dispersion (PMD) produces extra phase drift. In order to minimize this effect, ALMA specified very low PMD for all the equipment in the optical path of the signal carrying the phase references. Given that the line length correction scheme uses fiber stretchers that mechanically change the length of a long section of the fiber, special attention needs to be put in aligning the input polarization state with the axis of this device that minimizes the polarization change produced when the stretcher moves. This work presents an innovative optimization algorithm for the fiber stretchers used in ALMA, which was developed during the realization of this work. It allows a fast and accurate identification of this axis of minimal polarization change, compared with the original method; this algorithm produced a 70% reduction of the average calibration time and a 50% reduction of the average residual calibration. A review of the time reference transfer system used in ALMA is also made, explaining the challenges that it faces and the way they are overcome. Then the effect of PMD is presented, showing different PMD compensation and measurement techniques. In addition, this work presents PMD measurements made on ALMA photomixers and fiber stretchers, and of buried fiber installations of the Very Large Array (VLA) and ALMA.
Tian, Jie, Dong Hou, Nan Xie y Yongsheng Cheng. "METER-LEVEL TDOA MULTILATERATION SYSTEM BASED ON HIGH PRECISION PHASE SYNCHRONIZATION OVER FIBER OPTICAL LINKS". International Foundation for Telemetering, 2017. http://hdl.handle.net/10150/626954.
Texto completoSekkiou, Imene. "Design of communication systems based on broadband sources for fiber and free space optical links". Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/172542.
Texto completo[CA] Les comunicacions òptiques sense fils (OWC) constitueixen una tecnologia molt prometedora per al desenvolupament de futures comunicacions sense fils. De fet, ha despertat un interés creixent entre els investigadors i diverses empreses de tot el món treballen actualment en el desenvolupament de xarxes sense fils de molt alta velocitat. Les comunitats científica i industrial consideren la OWC com una tecnologia complementària en les seues diverses formes: comunicacions òptiques en l'espai lliure (FSO), comunicacions de llum visible (VLC) o fidelitat de la llum (Li-Fi). L'espectre òptic ha sigut considerat durant molts anys com una gran oportunitat per a les comunicacions sense fils, especialment a causa de la saturació de l'espectre de radiofreqüència (RF). Aquesta dissertació tracta de l'ús de fonts de banda ampla en sistemes de transmissió de llum visible (VLC), així com en sistemes de transmissió en l'espectre infraroig per fibra òptica. En el treball de recerca realitzat es poden distingir tres parts: ¿ En la primera part, es considera l'estudi i la simulació de components de Díodes Emissors de Llum (LED) amb el software WIEN2k centrant-se en les propietats òptiques i elèctriques dels elements II-VI. ¿ La segona part tracta del disseny, la implementació i les proves de diferents prototips de comunicació VLC per a la transmissió analògica i digital de manera simplex i semidúplex. Hem demostrat un sistema OWC emprant una font de banda ampla (LED) per a la transmissió no sols de dades, sinó també per a la transmissió sense fil d'energia. A més, s'aborda el problema de la sincronització i la detecció del nivell "1" o "0" d'un bit en els sistemes de comunicació sense fil òptica implementats, que sorgeix a conseqüència de l'atenuació de la llum al llarg de la distància i al problema de la pèrdua de línia de visió (NLOS) entre l'emissor i el receptor. Per a fer front a aquest problema, s'ha proporcionat un protocol de comunicació que garanteix la transmissió fiable de dades digitals amb un algorisme de detecció de nivell de bits adaptatiu i s'ha demostrat la seua eficàcia mitjançant la transmissió de textos i imatges. ¿ A més, aquesta tesi aporta una solució per a la implementació de transmissors multiplexats en xarxes amb divisió de longitud d'ona (WDM) per a formats de modulació amb multiplexació per divisió de freqüència ortogonal (OFDM) basats en l'ús de fonts de banda ampla en l'espectre infraroig per a xarxes de fibra bidireccionals centralitzades. Malgrat les limitacions imposades per la dispersió cromàtica en l'ús d'aquest tipus de fonts òptiques, la inclusió d'unes certes estructures abans de la detecció permet la transmissió de senyals OFDM en enllaços òptics. En aquest treball s'ha demostrat experimentalment la reutilització de portadores, l'assignació dinàmica d'amplada de banda i la transmissió de senyals OFDM multibanda mitjançant l'ús de fonts òptiques de banda ampla en xarxes WDM. Els principals resultats obtinguts en cada part d'aquesta tesi doctoral mostren els procediments d'estudi, l'eficàcia de les solucions proposades i les limitacions trobades.
[EN] Optical wireless communication (OWC) is a very promising technology for future wireless communications developments. It has attracted increasing interest from researchers and several companies around the world are currently working on the development of very high-speed wireless networks. The scientific and industrial communities believe that OWC will be a complementary technology in its various forms: Free Space Optical communications (FSO), Visible Light Communications (VLC), Light Fidelity (Li-Fi). In fact, the optical spectrum has been considered for many years as a great opportunity for wireless communications especially due to the saturation of the radio frequency (RF) spectrum. This dissertation deals with the use of broadband sources in visible light transmission systems (VLC) as well as fiber optic systems. To carry out the research, three parts can be distinguished: In the first part, we consider the study and simulation of Light Emitting Diode (LED) components with the WIEN2k software by focusing on the optical and electrical properties of elements II-VI. The second part deals with the design, implementation and testing of different VLC communication prototypes for analog and digital transmission in simplex and half-duplex mode. We have demonstrated that an OWC system using a broadband source (i.e. an LED) can be used not only for data transmission, but also for wireless power transmission. Moreover, the synchronization problem and the detection of level "1" or "0" of a bit often arise in the optical wireless communication systems. This is a result of the attenuation nature of the light over the distance and the problem of Non Line-Of-Sight (NLOS) between the emitter and the receiver. To deal with this problem, a communication protocol ensuring reliable digital data transmission with an adaptive bit level detection algorithm has been provided and its effectiveness has been demonstrated by the transmission of texts and images. In addition, this thesis provides a solution for the implementation of wavelength division multiplexed - orthogonal frequency division multiplexed (WDM-OFDM) transmitters based on the use of broadband sources in the infrared spectrum for centralized bidirectional fiber networks. Despite the chromatic dispersion that avoids the use of this type of optical sources, the inclusion of certain structures before detection allows the transmission of OFDM signals in optical links. Carrier reuse, dynamic bandwidth allocation and multiband OFDM signals transmission will be experimentally demonstrated by using optical broadband sources in WDM networks. The main results obtained during this thesis work demonstrate the study procedures, for each part, the effectiveness of the proposed solutions as well as the constraints encountered.
Sekkiou, I. (2021). Design of communication systems based on broadband sources for fiber and free space optical links [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172542
TESIS
Mondanos, Michael. "Characterisation and investigation of polarisation phenomena for application in all-in-line optical fibre sensing and communication systems". Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419795.
Texto completoMalekizandi, Mohammadreza [Verfasser], Franko [Akademischer Betreuer] Küppers y Manfred [Akademischer Betreuer] Berroth. "Generation and Transmission of Optical Ultra-wideband Signals for Optical Fiber and Wireless Communication Links / Mohammadreza Malekizandi ; Franko Küppers, Manfred Berroth". Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2018. http://d-nb.info/116301351X/34.
Texto completoKanprachar, Surachet. "Modeling and Analysis of the Effects of Impairments in Fiber Optic Links". Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/35245.
Texto completoMaster of Science
Predehl, Katharina [Verfasser] y Theodor W. [Akademischer Betreuer] Hänsch. "A 920 km optical fiber link for frequency metrology at the 19th decimal place / Katharina Predehl. Betreuer: Theodor W. Hänsch". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2012. http://d-nb.info/1028191847/34.
Texto completoHorský, Tomáš. "Rozšíření optického vláknového přenosového systému". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442378.
Texto completoYeo, Yong-Kee. "Dynamically Reconfigurable Optical Buffer and Multicast-Enabled Switch Fabric for Optical Packet Switching". Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/14615.
Texto completoCháma, Jakub. "Optimalizace výrobního procesu ve společnosti ADC Czech Republic s.r.o". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-401019.
Texto completoDong, Bo. "Fiber Optic Sensors for On-Line, Real Time Power Transformer Health Monitoring". Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77175.
Texto completoPh. D.
Hadi, Muhammad Usman. "Digital predistortion for compensation of nonlinearities in Radio over Fiber Links". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
Buscar texto completoSambaraju, Rakesh. "Photonic Modulation and Demodulation techniques for Multi-Gb/s Millimetre wave Wireless Links". Doctoral thesis, Universitat Politècnica de València, 2010. http://hdl.handle.net/10251/8857.
Texto completoSambaraju -, R. (2010). Photonic Modulation and Demodulation techniques for Multi-Gb/s Millimetre wave Wireless Links [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8857
Palancia
Mauer, Jindřich. "Optimalizace výrobního procesu za využití metod štíhlé výroby ve firmě ADC Czech Republic s.r.o". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-382289.
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