Dissertations / Theses on the topic 'Electro-optic devices'
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1
DeRose, Christopher Todd. "Electro-Optic Polymers: Materials and Devices." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/195650.
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Electro-optic (EO) polymers are an attractive alternative to inorganic nonlinear materials. EO polymers with a Pockel's coefficient, r33, greater than 320 pm/V have been recently demonstrated. In addition to their high EO activity, EO polymers have the additional benefit that their dielectric constants at optical and millimeter wave frequencies are closely matched which allow for bandwidths which are limited only by the resistive losses of traveling wave electrodes. The amorphous nature of the host polymer makes heterogeneous integration of the materials on any substrate possible. The devices which will have the most immediate impact based on these recent materials developments are EO waveguide modulators. Performance benchmarks of less than 6 dB insertion loss, sub-volt Vpi and greater than 100 GHz bandwidth have been achieved separately however, the challenge of achieving all of these benchmarks in a single device has not yet been met.The aim of this dissertation is to optimize passive materials to achieve efficient in device poling of EO polymers, optimize the chromophore loading of the active polymers and to optimize waveguide modulators for device performance within a particular system, analog RF photonic links. These optimizations were done by defining figures of merit for the materials and modulators. This research strategy has led to significant improvements in poling efficiency as well as modulators with record low insertion losses which maintain a low half-wave voltage; on the order of 1 - 2 Volts. Using this optimization strategy and state of the art EO polymers, devices which meet or surpass the benchmark performance values in all categories are expected in the near future.
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Taboada, John Martin. "Polymer electro-optic and thermo-optic devices for optical interconnects /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3023563.
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Choy, Wallace Chik-Ho. "Modelling of acousto-optic and electro-optic quantum-wells modulation devices." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/843772/.
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In this thesis, the surface acoustic waves (SAWs) and quantum well (QW) interdiffusion technologies are used to develop modulation devices including electrooptic and electro-absorption QW modulators. The modulation devices are crucial components for generating optical signals in opto-electronic circuits in the use of communication systems. The propagation of SAWs and it effects on a III-V semiconductor QW are modelled to determine the change of the QW subband structure. The change of optical properties is evaluated so that the optical modulators using SAWs can be studied and optimised. For the interdiffusion technology, the constituent atom composition after interdiffusion is modelled by solving the diffusion equations. The modifications of the QW subband structure which change the QW optical properties are studied here for the use of the QW modulators and lasers. SAWs are generated by interdigital transducers deposited on the top surface of device structures. Our aims here are to optimise the change of optical properties, including the change of the QW refractive index and absorption coefficient and to simplify the structure of the transducer by increasing and reducing the SAW wavelength and power respectively. The theoretical results show that by optimising the QW structures in a stack from a single QW to a diffused QW (DFQW) and pairs of asymmetric double QW (DQW), the optical change can be enhanced 100 times as compared to conventional bulk SAW modulators. Besides, the SAW frequency and power can be reduced to ~100MHz and few mW per SAW wavelength respectively. Recently, SAWs with a frequency of ~ 100MHz have been demonstrated in single QW by others. These suggest that SAW-QW modulators can be realised in the near future. DFQWs used as both the passive cladding regions and active region of modulation devices are studied here. The results show that an electro-optical phase modulator with disorder delineated optical confinement is comparable to existing phase modulators. We also propose to use DFQWs as the active region of optical devices to produce TE and TM modes polarisation insensitive optical properties in both AlGaAs/GaAs and InGaAsP/InP QWs. At the same time, InGaAsP DFQW have been demonstrated by others as the polarisation insensitive QW amplifiers. This indicates the potential of DFQW to realise the polarisation insensitive QW optical devices.
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Wallace, Chik-Ho Choy. "Modelling and electro-optic quantum-wells modulation devices." Thesis, University of Surrey, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267967.
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Chen, Jianxiao. "Tunable electro-optic devices for fiber optical RF signal processing." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3203495.
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Thesis (Ph. D.)--University of California, San Diego, 2006.Title from first page of PDF file (viewed March 1, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Mason, Karen B. "An electro-optic logic system employing liquid crystal display devices." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329084.
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Jobanputra, Manish C. "Investigation of Organic Thin Films for Application in Electro-Optic Devices." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1017755544.
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Gan, Haiyong. "Electro-optic Polymer Based Fabry-Perot Interferometer Devices for Optoelectronic Applications." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195839.
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Fabry-Perot interferometer (FPI) devices are designed based on the electro-optic (EO) activities of nonlinear optical (NLO) polymer materials for tunable optical filters (TOFs) and spatial light modulators (SLMs). The performance of the EO polymer based FPI devices is theoretically modeled with first order approximation on the FPI cavity interface phase dispersion. NLO materials including TCBD coupled hybrid sol-gel, AJL8/amorphous polycarbonate (APC), and AJLS102/APC are incorporated in FPI structures with distributed Bragg reflector mirrors and transparent conducting oxide electrodes for TOFs. High finesse (over 200), low drive voltage (10 dB isolation ratio with 5 V), and fast settling time (about sub-millisecond) are achieved. The physical origin of the large tunabilities is explored and the contributions from EO effect and inverse piezoelectric effect are analyzed. EO polymer SWOHF3ME/APC is employed in FPI devices with simplified structures for SLMs. Modulation beyond megahertz level is achieved with constant modulation ratio from DC frequency to high operation speed. The operation speed can be potentially over gigahertz with improved device and drive circuit design. When the EO polymer based SLM is configured to work at near the resonance band of the NLO material, the spectral tunability is increased due to resonance enhanced EO activity and the SLM performance is significantly improved. The EO polymer based FPI devices can be further optimized and are promising candidates for many optoelectronic applications.
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Wu, Xiaohua. "Field simulation and calibration in external electro-optic sampling /." *McMaster only, 1996.
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Tulli, Domenico. "Micro-nano structured electro-optic devices in LiNbO3 for communication and sensing." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/81118.
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A material that is enabling integrated optics is the ferroelectric crystal Lithium Niobate (LiNbO3), which has excellent electro-optical, acousto-optical and nonlinear optical properties. Moreover, it can be doped with laser-active ions and allows for simple fabrication of low-loss optical waveguides.
The broad aim of this work is to develop and introduce advanced micro- and nano-fabrication techniques for LiNbO3 and a new class of integrated based telecommunication and sensing devices. The techniques developed include precise micro-domain inversion, etching, bonding and thin film fabrication.
From a device point of view, domain inversion is used to improve the electro-optic response of LiNbO3 waveguide modulators in terms of bandwidth and driving voltage. With respect to standard single-domain structures, larger bandwidths and lower driving voltages can be obtained, thus achieving figure of merits for the electro-optic response that are up to 50% larger. As a demonstration, a chirp-free modulator, having ~2V switching voltage and bandwidth of 15 GHz, was fabricated by placing the waveguide arms of a Mach-Zehnder interferometer in opposite do- main oriented regions. The modulator could be driven in a single-drive configuration with inexpensive low-voltage drivers, e.g. a SiGe based RF amplifier, typically used for electro-absorption devices.
A further aspect of this work focuses on the development of devices for the precise measurement of strong electric fields, which are typically generated in power stations and transmission lines. Therefore, two new integrated electric field sensors are proposed, each of which exploits the aforementioned micro-fabrication techniques. The first device is based on a proton-exchange waveguide at cut-off, centered on a few microns wide domain-inverted region in a z-cut LiNbO3 substrate. The sensor’s performance is demonstrated by detecting DC fields up to 2.6 MV/m and high-frequency (1.1 GHz) fields ranging from 19 V/m to 23 kV/m. The second proposed device is fabricated by direct bonding a z-cut LiNbO3 substrate on top of a cut-off proton-exchanged waveguide centered on the domain-inverted region. It is possible to detect electric fields as high as 2 MV/m at low frequency with improved sensitivity compared to the previous device. These features make the devices suitable for use in high electric field and harsh conditions without endangering the operator. The conclusions section of the Thesis presents possible future developments which will contribute to increase the impact of the work in the optical telecommunication and sensing industries.
After a brief introduction, the second chapter describes the basic properties of the material used in the thesis work: Lithium Niobate (LiNbO3). This includes the properties related to its ferroelectric crystal structure and the subsequent applications. Chapter three presents the micro-fabrication techniques, over 3 inch LiNbO3 wafers, developed at ICFO during this work. The chapter begins with a description of waveguides fabrication by Annealed Proton Exchange (APE). The mid-part of the chapter outlines the fabrication procedure for domain inversion using electric field poling technique and liquid electrodes while the last part describes the bonding technique to permanently join LiNbO3 with different substrates, namely Si, SiO2 and another LiNbO3. Moreover, lapping and polishing techniques for thin plate fabrication are presented. The forth chapter firstly introduces the
fundamentals and main characteristics of travelling-wave LiNbO3 Mach-Zehnder modulators. Secondly, a new modulator design is proposed. It is based on domain inverted LiNbO3, with improved performance with respect to existing devices. The modulator characterization and the results obtained from the new design are presented. The chapter five begins with a literature review about DC and low frequency electric field optical sensors. Afterwards, two novel all-optical electric field sensors are presented. Both devices are based on a proton-exchange, domain inversion and bonding techniques. The sensors characterization, including the test set-up and the performance results are discussed. Finally, in chapter six, several conclusions on the thesis work and possible future work directions are presented.Uno de los materiales que permite el avance de la tecnología de dispositivos ópticos integrados es el niobato de litio (LiNbO3). Se trata de un cristal ferro-eléctrico, con excelentes propiedades electro-ópticas, acusto-ópticas y no lineales. Además, es posible fabricar guías de onda de bajas pérdidas mediante las técnicas de intercambio protónico (PE) y difusión de titanio. El objetivo principal de este trabajo es el desarrollo y la introducción tanto de las técnicas avanzadas de micro-nano fabricación para el niobato de litio como de nuevos dispositivos ópticos integrados para las comunicaciones ópticas y la detección de campo eléctricos de alto voltaje. La técnicas de fabricación desarrolladas incluyen inversión de dominios mediante la técnica de poling de alto voltaje, grabado, bonding y capas delgadas. Desde el punto de vista de los dispositivos, la inversión de dominios ha sido utilizada para mejorar la respuesta electro-óptica de los moduladores en LiNbO3 en términos de ancho de banda (BW) y voltaje de control (Vπ). En comparación con los moduladores comerciales actuales de un único dominio, con esta técnica es posible obtener mayores anchos de banda y menores voltajes de control resultando en un aumento del 50% del producto BW·Vπ. Para demonstrar la eficacia de la técnica desarrollada, se ha fabricado un modulador Mach-Zehnder chirp-free poniendo los brazos del interferómetro en dos regiones de dominios opuestos. De las mediciones efectuadas se han obtenidos valores de voltaje de control de 2V y ancho de banda de 15 GHz. Estos resultados muestran que los dispositivos desarrollados pueden reducir el coste total de funcionamiento, ya que permiten el uso de controladores económicos de Si-Ge que operan en el rango de los 2V. Otro aspecto de este trabajo se enfoca en el desarrollo de dispositivos para medir, de forma exacta, altos campos eléctricos, que normalmente son generados en las centrales eléctricas y en las líneas de transmisión. Por este motivo, se han desarrollado dos sensores de campo eléctrico mediante las técnicas de micro-fabricación anteriormente mencionadas. El primer dispositivo está basado en una guía fabricada mediante intercambio protónico en LiNbO3 z-cut, diseñada a la frecuencia de corte y centrada en una región de dominio invertido de 10 micras de ancho y 10mm de largo. El rendimiento del dispositivo se ha demostrado detectando campos a baja frecuencia con amplitudes de hasta 2.6MV/m y campos a la frecuencia de 1.1GHz con amplitudes desde 19V/m hasta 23kV/m. El segundo dispositivo se ha fabricado mediante bonding directo de un sustrato de LiNbO3 encima de una guía PE diseñada a la frecuencia de corte y centrada en una región de dominio invertido de 10 micras de ancho y 10mm de largo. El dispositivo se ha caracterizado a baja frecuencia y ha sido posible medir campos eléctricos de hasta 2MV/m con un aumento de sensibilidad comparado con el primer dispositivo fabricado sin la técnica del bonding. Estos resultados muestran que los dispositivos desarrollados pueden ser utilizados para mediciones de campos eléctricos intensos en condiciones peligrosas sin ningún riesgo para el operador. Después de una breve introducción en el Capítulo 1 de esta Tesis, las propiedades del LiNbO3 se discuten en el Capítulo 2, prestando especial atención a sus características ópticas y electro-ópticas. El Capítulo 3 presenta las técnicas de micro fabricación desarrolladas durante este trabajo sobre sustratos de 3 pulgadas. En particular, se presentan las técnicas de fabricación de guías mediante intercambio protónico, de inversión de dominios mediante poling de alto voltaje, de bonding de LiNbO3 con diferentes sustratos (LiNbO3 , SiO2, Si) y la fabricación de capas delgadas. El Capítulo 4 ofrece una introducción sobre los moduladores interferométricos Mach-Zehnder de onda propagada, presentando sus principales características. Además se presenta una nueva estructura de modulador basada sobre inversión de dominios y los resultados obtenidos. El Capítulo 5 empieza con una introducción sobre los sensores de campo eléctrico y después se presentan dos nuevos sensores de campo eléctrico completamente ópticos fabricados en LiNbO3 z-cut. Los dispositivos están basados en las técnicas de intercambio protónico, inversión de dominios y bonding directo. Finalmente, en el Capítulo 6 se presentan las conclusiones y posibles desarrollos futuros que pueden contribuir al aumento del impacto de este trabajo en las industrias de comunicaciones ópticas y de detección.
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Musgrave, Bronje. "Electro-optic studies of the flexoelectric effect in chiral nematic liquid crystals." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313146.
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Lauermann, Matthias [Verfasser]. "Silicon-organic hybrid devices for high-speed electro-optic signal processing / Matthias Lauermann." Karlsruhe : KIT Scientific Publishing, 2018. http://www.ksp.kit.edu.
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Li, Chao. "Silicon-based optical microresonator devices : polygonal microdisk channel filters and electro-optic modulators/switches /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20LI.
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Sodagar, Majid. "Enabling integrated nanophotonic devices in hybrid cmos-compatible material platforms for optical interconnection." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53952.
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Recent impactful advances in integrated photonics undoubtedly owe much to silicon and its associated enabling platform (SOI). Although silicon has proved to be an indispensable element in many photonic systems yet it seems that it is not the ultimate solution to address all the challenges facing the photonics community. Therefore, integration of silicon with other optical materials featuring diverse properties is highly desirable. Such integration will be conducive to platforms which are naturally more capable and are suited for implementation of a wider range of optical devices and diverse functionalities. This dissertation is dedicated to design and implementation of integrated optical elements for hybrid material platforms. The basic theoretical foundation of integrated photonics is laid out in Chapter 2. In Chapter 3, an interlayer grating coupler for a specific hybrid material platform is designed, and demonstrated. Considering the fact that in almost all integrated photonic platforms, fabrication imperfections lead to an unpredictable shift in the wavelength of operation of individual devices, post fabrication tuning/trimming is inevitable. A number of widely used post fabrication trimming/tuning methods are briefly reviewed in Chapter 4 with special emphasis on a method based on electron beam exposure. In Chapter 5, an ultra-fast, low-power, and self-trimmable electro-optic modulator in demonstrated on a Si-based multilayer platform. Due to its remarkable optical and electronic properties, graphene has become a valuable material for opto-electronic applications. Integration of this novel 2D material with SOI platform is investigated in Chapter 6. Graphene-based electro-optic modulation through absorption and refractive-index change is successfully demonstrated using electrostatic gating mechanism. Chapter 7 is devoted to demonstration of a field-programmable 2 by 2 optical switch on a vertically stacked Si/SiO2/SOI platform. In Chapter 8, the peak-dragging phenomenon in a nanobeam photonic crystal cavity is studied. The optical bistability associated with this nonlinear phenomenon is of great interest for all-optical processing and sensing application. Future directions of this thesis are also discussed in the last Chapter.
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Lu, Xuejun. "High performance thermo-optic switch and electro-optic modulator based on polymeric multi-mode waveguides with high device packing density for optical network applications." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3034934.
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Zuo, Yiying 1974. "Design, analysis, and implementation of multi-port refraction based electro-optic switches." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103035.
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Electro-optic (EO) beam deflectors are voltage-controlled devices widely used for scanning and switching applications. For example, high-speed, low-loss optical switches aimed at future optical networks can be built on EO deflectors. Novel EO deflectors distinguish themselves with a much-improved steering performance, high-speed response and simple fabrication requirements. Patterned ferroelectric crystals such as LiTaO3 are first poled to provide the required prism shaped domain structures. The application of an electrical field across the entire crystal can then be used to drive the trajectory of the beam as it travels through the poled wafer. The electric field induces an index change of opposite magnitude on the adjacent domain regions in the EO device, causing the optical beam to refract at the interfaces.Although rectangular geometry is extensively employed in EO devices, nonrectangular scanners have demonstrated better deflection performance. Two new nonrectangular geometries capable of further enhancing the deflection performance of EO beam scanners, proposed in this dissertation, were constructed. Their parabola and half-horn geometries provide 2-3 degrees of steering, which is 2-3 times greater than the steering provided by rectangular deflectors.
EO deflectors based on the parabola and the half-horn geometries, which can provide larger deflection angles, were built. These devices demonstrated a deflection angle of 3.1°, less than 5 dB of insertion loss from fiber to fiber, and -40 dB of crosstalk.
Two packaged optical switches using rectangular EO deflectors were demonstrated. By combining these EO deflectors with fiber collimators and high voltage packaging, high speed optical switches were built and characterized. The switch design was based on a 500mum z-cut LiTaO3 single crystal wafer fabricated using the domain inversion method. The 1x2 switch had a maximum deflection angle of 1.22° with an applied voltage of 1.1 kV and the 1x4 switch had a maximum deviation angle of 2.14°, with an applied voltage of 1 kV. The average insertion loss and crosstalk figures were 2.36 dB and -36 dB, respectively. The worst case switching time was 86 ns.
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Lentine, Anthony L. "Issues in the design of self electro-optic effect devices for optical signal processing." Thesis, Heriot-Watt University, 1993. http://hdl.handle.net/10399/1474.
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Mohsin, Muhammad Verfasser], Joachim [Akademischer Betreuer] [Knoch, and Wilfried [Akademischer Betreuer] Mokwa. "Graphene based Electro Optic and Digital Logic Devices / Muhammad Mohsin ; Joachim Knoch, Wilfried Mokwa." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1161809007/34.
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Mohsin, Muhammad [Verfasser], Joachim [Akademischer Betreuer] Knoch, and Wilfried [Akademischer Betreuer] Mokwa. "Graphene based Electro Optic and Digital Logic Devices / Muhammad Mohsin ; Joachim Knoch, Wilfried Mokwa." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1161809007/34.
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Evans, Jonathan W. "Beam Switching of an Nd:YAG Laser Using Domain Engineered Prisms in Magnesium Oxide Doped Congruent Lithium Niobate." University of Dayton / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1281366442.
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HAGEN, JOSHUA A. "INVESTIGATION OF MARINE DERIVED DNA FOR USE AS A CLADDING LAYER IN ELECTRO-OPTIC DEVICES." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1078432550.
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An, Dechang. "Electro-optic polymer-based monolithic waveguide devices with multi-functions of amplification switching and modulation." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3035933.
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Bhattacharjee, Sanchali. "Novel concepts in the design and synthesis of organic nonlinear optical and electro-optic materials /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/8605.
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Ruege, Alexander Charles. "Electro-Optic Ring Resonators in Integrated Optics For Miniature Electric Field Sensors." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322521235.
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Lauermann, Matthias [Verfasser], and C. [Akademischer Betreuer] Koos. "Silicon-organic hybrid devices for high-speed electro-optic signal processing / Matthias Lauermann ; Betreuer: C. Koos." Karlsruhe : KIT-Bibliothek, 2018. http://d-nb.info/1153828596/34.
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Gutiérrez, Campo Ana María. "Development of integrated silicon photonics modulation devices for digital and analog applications." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/33330.
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Silicon photonics is one of the most exciting and fastest growing photonic technologies
in recent years. The salient feature of this technology is its compatibility with the
mature silicon IC manufacturing based on complementary metal-oxide semiconductor
(CMOS) processes widely used in microelectronic industry. Another motivation is the
availability of high-quality silicon-on-insulator (SOI) planar waveguide circuits that
offer strong optical confinement due to the high index contrast between silicon (n=3.45)
and SiO2 (n=1.45). This opens up miniaturization and very large scale integration of
photonic devices allowing photonic integrated circuits for a wide range of applications
and markets, from optical telecommunications to bio-photonic devices or precise fibre
sensors. Optical modulators are key building-blocks for high speed signal transmission
and information processing in any photonic interconnection solution. The work
developed in this thesis, as part of the objectives of the European project HELIOS in
which it is framed, is essentially focused on realizing compact and efficient modulators
integrated on silicon chips.
The thesis consists of three main chapters as well as the concluding section on the
work accomplished. Chapter one is aimed at giving a general description of the benefits
of using silicon photonics, showing its challenges and opportunities as well as at giving
a deeply overview of all issues related to the electro-optic modulation. Chapter two is
devoted to develop silicon modulators with high features for digital applications.
Specifically, new optical structures different to the conventional ones are presented with
the aim of enhancing the modulation performance or at least several critical parameters
in the modulation. Chapter three is dedicated to the analog applications. The concept of
microwave photonics is described as well as different researches carried out in the
analog scope for application in the field of integrated microwave photonics, all of them
using CMOS-compatible electro-optic silicon modulators which validate the potential of
silicon photonics as a promising approach for enabling the development of integrated
microwave photonics applications. Finally, conclusions on the work realized are
provided in Chapter 4.La fotónica de silicio es una de las tecnologías fotónicas que está experimentando un crecimiento más excitante y rápido en los últimos años. La característica más destacada de esta tecnología es su compatibilidad con las maduras técnicas de fabricación de circuitos integrados de silicio basadas en los procesos ¿complementary metal-oxide semiconductor¿ (CMOS) ampliamente utilizados en la industria microelectrónica. Otra motivación es la disponibilidad de circuitos de guía de ondas planas de silicio sobre aislante (SOI) de alta calidad que ofrecen un fuerte confinamiento óptico debido al alto contraste índices entre el silicio (n=3,45) y el SiO2 (n = 1,45). Esto abre las puertas a la miniaturización y a la integración a gran escala de dispositivos fotónicos lo que resulta en circuitos fotónicos integrados para una amplia gama de aplicaciones y mercados, desde telecomunicaciones ópticas a dispositivos bio-fotónicos o sensores de fibra precisos. Los moduladores ópticos son elementos básicos fundamentales para la transmisión de señales a alta velocidad y el procesado de información en cualquier solución de interconexión fotónica. El trabajo desarrollado en esta tesis, como parte del los objetivos del proyecto Europeo HELIOS en el que está enmarcada, se centra fundamentalmente en realizar moduladores compactos y eficientes, integrados en chips de silicio. La tesis consiste en 3 capítulos principales así como una sección de conclusiones del trabajo conseguido. El capítulo uno está destinado a dar una descripción general de los beneficios del uso de la fotónica de silicio, mostrando sus retos y oportunidades, así como a dar una visión profunda de todos los aspectos relacionados con la modulación electro-óptica. El capítulo dos está dedicado a desarrollar moduladores de silicio de altas prestaciones para aplicaciones digitales. Específicamente, se presentan nuevas estructuras ópticas diferentes a las convencionales con el objetivo de mejorar el rendimiento de la modulación o al menos algunos parámetros críticos en la modulación. El tercer capítulo se dedica a las aplicaciones analógicas. Se describe el concepto de la fotónica de microondas, así como diferentes investigaciones llevadas a cabo en el ámbito analógico para su aplicación en el campo de la fotónica integrada de microondas, todas ellas usando moduladores electro-ópticos de silicio compatibles con los procesos de fabricación CMOS, lo que valida el potencial de la fotónica de silicio como un prometedor enfoque para permitir el desarrollo de aplicaciones de la fotónica integrada de microondas. Por último, las conclusiones sobre el trabajo realizado se proporcionan en el Capítulo 4.
Gutiérrez Campo, AM. (2013). Development of integrated silicon photonics modulation devices for digital and analog applications [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/33330
TESIS
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Zanzi, Andrea. "Passive and active silicon photonics devices at TLC telecommunication wavelengths for on-chip optical interconnects." Doctoral thesis, Universitat Politècnica de València, 2020. http://hdl.handle.net/10251/149377.
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[EN] Optical technologies are the backbone of modern communication systems providing
high-speed access to the Internet, efficient inter and intra-data center interconnects
and are expending towards growing research fields and new markets such as satel-
lite communications, LIDARs (Laser Imaging Detection and Ranging) applications,
Neuromorphic computing, and programable photonic circuits, to name a few. Be-
cause of its maturity and low-cost, silicon photonics is being leveraged to allow these
new technologies to reach their full potential.As a result, there is a strong need for
innovative, high-speed and energy-efficient photonic integrated building blocks on
the silicon platform to increase the readiness of silicon photonic integrated circuits.
The work developed and presented in this thesis is focused on the design and char-
acterization of advanced passive and active devices, for photonic integrated circuits.
The thesis consists of three main chapters as well as a motivation and concluding
sections exposing the rationale and the accomplishments of this work. Chapter one
describes the design and characterization of an electro-optical Mach-Zehnder mod-
ulator embedded in highly efficient vertical pn junction exploiting the free-carrier
dispersion effect in the O-band.. Chapter two is devoted to the design and charac-
terization of a novel geometry of asymmetrical multimode interference device and
its implementation in a Mach-Zehnder modulator. Chapter three is dedicated to
the design and characterization of innovative 1-dimensional photonic crystal designs
for slow- lightmodulation applications. An extensive analysis of the main trade-off
arising from the use of slow light is presented.[ES] Las tecnologías ópticas son el eje vertebrador de los sistemas de comunicación mod- ernos que proporcionan acceso de alta velocidad a la Internet, interconexiones efi- cientes entre centros de datos y dentro de ellos. Además, se están expandiendo hacia campos de investigación crecientes y nuevos mercados como son las aplicaciones de comunicaciones por satélite, los LIDAR (Laser Imaging Detection and Ranging), la computación neuromórfica y los circuitos fotónicos programables, por nombrar algunos. La fotónica de silicio está considerada y aceptada ampliamente como una de las tecnologías clave para que dichas aplicaciones puedan desarrollarse. Como resultado, hay una fuerte necesidad de estructuras fotónicas básicas integradas que sean innovadoras, que soporten altas velocidades de transmisión y que sean más eficientes en términos de consumo de potencia, a fin de aumentar la capacidad de los circuitos integrados fotónicos de silicio. El trabajo desarrollado y presentado en esta tesis se centra en el diseño y la car- acterización de dispositivos avanzados pasivos y activos, para circuitos fotónicos integrados. La tesis consta de tres capítulos principales, así como de sendas sec- ciones de motivación y conclusiones que exponen los fundamentos y los logros de este trabajo. El capítulo uno describe el diseño y la caracterización de un modulador electro-óptico Mach-Zehnder incorporado en una unión pn vertical altamente eficien- ciente que explota el efecto de dispersión de plasma en banda O. El capítulo dos está dedicado al diseño y caracterización de una nueva geometría de dispositivo de interferencia multimodo asimétrico y su aplicación en un modulador Mach-Zehnder. El capítulo tres está dedicado al diseño y caracterización de innovadores cristales fotónicos unidimensionales para aplicaciones de modulación con luz lenta. Se pre- senta un amplio análisis de los principales retos derivados del uso de la misma.
[CA] Les tecnologies òptiques són l'eix vertebrador d'aquells sistemes de comunicació moderns que proporcionen accés d'alta velocitat a la Internet, així com intercon- nexions eficients inter i entre centres de dades. A més a més, s'estan expandint cap a camps d'investigació creixents i nous mercats com són les aplicacions de co- municacions per satèl·lit, els LIDAR (Laser Imaging Detection and Ranging), la computació neuromòrfica i els circuits fotònics programables, entre d'altres. La fotònica de silici és considerada i acceptada àmpliament com una de les tecnologies clau i necessàries perquè aquestes aplicacions puguen desenvolupar-se. Per aquest motiu, es fa necessària l'existència d'estructures fotòniques bàsiques integrades que siguen innovadores, que suporten altes velocitats de transmissió i que siguen més eficients en termes de consum de potència, a fi d'augmentar la capacitat dels cir- cuits integrats fotònics de silici. El treball desenvolupat i presentat en aquesta tesi se centra en el disseny i la caracterització de dispositius avançats passius i actius, per a circuits fotònics integrats. La tesi consta de tres capítols principals, així com d'una secció de motivació i una altra de conclusions que exposen els fonaments i els assoliments d'aquest treball. El capítol u descriu el disseny i la caracterització d'un modulador electro-òptic Mach-Zehnder incorporat en una unió pn vertical d'alta efi- ciència que explota l'efecte de dispersió de plasma en la banda O. El capítol dos està dedicat al disseny i caracterització d'una nova geometria de dispositiu d'interferència multimode asimètric així com a la seua aplicació en un modulador Mach-Zehnder. El capítol tres està dedicat al disseny i caracterització d'innovadors cristalls fotònics unidimensionals per a aplicacions de modulació amb llum lenta. S'inclou també una anàlisi detallada dels principals reptes derivats de l'ús d'aquest tipus de llum.
I want to thank you the Generelitat Valenciana and the European Project L3MATRIX for the funding, without them my doctorate would not taken place.
Zanzi, A. (2020). Passive and active silicon photonics devices at TLC telecommunication wavelengths for on-chip optical interconnects [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/149377
TESIS
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Hernandez, Gerardo Rodriguez. "Study of mixed mode electro-optical operations of Ge2Sb2Te5." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:5bb8c1f5-2f4b-4eb0-a61a-3978af04211f.
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Chalcogenide based Phase Change Materials are currently of great technological interest in the growing field of optoelectronics. Ge2Sb2Te5 (GST) is the most widely studied phase change material, and it has been commercially used in both optical and electronic data storage applications, due to its ability to switch between two different atomic configurations, at high speed and with low power consumption, as well as its high optical and electrical contrast between amorphous and crystalline states. Despite its well-known optical and electrical properties, the operation in combination of optical and electrical domains has not yet been fully investigated. This work studies the operation of GST nano-devices exposed to a combination of optical and electrical stimuli or mixed mode by asking, is it possible to electrically measure an optically induced phase change, or vice versa? If so, how do the optical and electrical responses relate to each other, and is it possible to operate GST with a combination of optical and electrical signals? What are the technical constraints that need to be considered in order to fabricate GST devices that could be operated either optically or electrically? In order to answer these questions, experiments that characterized the optical and electrical responses of GST based nano-devices were performed. It was found that different crystallization mechanisms may have influence in the response, and that the thermal and optical design characteristics of the device play a key role in its operation. Finally a proof of principle, of an opto-electonic memory device that can be read electrically, reset optically and write electrically, is presented. This opens up possibilities for the development of new opto-eloectronic applications such as non-volatile interfaces between future photonics and electronics, high speed optical communication detectors, high speed cameras, artificial retinas and many more.
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Bhatambrekar, Nishant. "Realizing a fractional volt half-wave voltage in Mach-Zehnder modulators using a DC biased push-pull method and synthesis and characterization of indole based NLO chromophores for improving electro-optic activity /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/11606.
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Smith, Kevin H. "In-fiber Optical Devices Based on D-fiber." BYU ScholarsArchive, 2005. https://scholarsarchive.byu.edu/etd/291.
Full textAbstract:
This dissertation presents the fabrication and analysis of in-fiber devices based on elliptical core D-shaped optical fiber. Devices created inside optical fibers are attractive for a variety of reasons including low loss, high efficiency, self-alignment, light weight, multiplexibility, and resistance to electromagnetic interference. This work details how D-fiber can be used as a platform for a variety of devices and describes the creation and performance of two of these devices: an in-fiber polymer waveguide and a surface relief fiber Bragg grating. In D-fiber the core is very close to the flat side of the ‘D’ shape. This proximity allows access to the fields in the fiber core by removal of the cladding above the core. The D-fiber we use also has an elliptical core, allowing for the creation of polarimetric devices. This work describes two different etch processes using hydrofluoric acid (HF) to remove the fiber cladding and core. For the creation of devices in the fiber core, the core is partially removed and replaced with another material possessing the required optical properties. For devices which interact with the evanescent field, cladding removal is terminated before acid breaches the core. Etching fibers prepares them for use in the creation of in-fiber devices. Materials are placed into the groove left when the core of a fiber is partially removed to form a hybrid waveguide in which light is guided by both the leftover core and the inserted material. These in-fiber polymer waveguides have insertion loss less than 2 dB and can potentially be the basis for a number of electro-optic devices or sensors. A polarimetric temperature sensor demonstrates the feasibility of the core replacement method. This work also describes the creation of a surface relief fiber Bragg gratings (SR-FBGs) in the cladding above the core of the fiber. Because it is etched into the surface topography of the fiber, a SR-FBG can operate at much higher temperatures than a standard FBG, up to at least 1100 degrees Celsius. The performance of a SR-FBG is demonstrated in temperature sensing at high temperatures, and as a strain sensor.
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Le, Hung Manh, and n/a. "Electronic Properties of Nanostructures from Hydrostatics and Hydrodynamics." Griffith University. School of Science, 1997. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20070403.094305.
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The behaviour of electrons in nanostructures such as quantum wells is of interest for the design of new electronic and electro-optic devices, and also for exploration of basic many-body physics. This thesis develops and tests improved methods for describing such electronic behaviour. The system used for this work was the parabolic quantum well (PQW), an important special system which has recently attracted much experimental and theoretical attention. We firstly report self-consistent nonlinear groundstate solutions of the Poisson equation together with the Thomas-Fermi (TF) hydrostatic equations. In contrast to most previous solutions, all the electron density profiles were inhomogeneous and continuous. We also added a von Weizsacker term with and without the exchange/exchange-correlation to the above treatment, using a novel numerical approach allowing for wider electron gases than previously possible. We also report for the first time the effects of spatially varying effective mass and dielectric function in theories of this type. To investigate infrared response of these systems, we apply new hydrodynamic theories recently proposed by Dobson. By using this type of theory, we simultaneously satisfy the Harmonic Potential Theorem (extended generalized Kohn theorem) and obtain the correct 2D plasmon dispersion, as well as obtaining the correct spacing of standing plasmons. Other inhomogeneous hydrodynamic theories do not achieve this. We also showed analytically an exact solution for a plasmon mode at the Kohn frequency in addition to one found in the Harmonic Potential Theorem. An open hydrodynamic theory was then developed based on this type of mode. Numerical application of Kohn Frequency Theorem theory was shown and the results were compared with other existing hydrodynamic theories.
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Le, Hung. "Electronic Properties of Nanostructures from Hydrostatics and Hydrodynamics." Thesis, Griffith University, 1997. http://hdl.handle.net/10072/366817.
Full textAbstract:
The behaviour of electrons in nanostructures such as quantum wells is of interest for the design of new electronic and electro-optic devices, and also for exploration of basic many-body physics. This thesis develops and tests improved methods for describing such electronic behaviour. The system used for this work was the parabolic quantum well (PQW), an important special system which has recently attracted much experimental and theoretical attention. We firstly report self-consistent nonlinear groundstate solutions of the Poisson equation together with the Thomas-Fermi (TF) hydrostatic equations. In contrast to most previous solutions, all the electron density profiles were inhomogeneous and continuous. We also added a von Weizsacker term with and without the exchange/exchange-correlation to the above treatment, using a novel numerical approach allowing for wider electron gases than previously possible. We also report for the first time the effects of spatially varying effective mass and dielectric function in theories of this type. To investigate infrared response of these systems, we apply new hydrodynamic theories recently proposed by Dobson. By using this type of theory, we simultaneously satisfy the Harmonic Potential Theorem (extended generalized Kohn theorem) and obtain the correct 2D plasmon dispersion, as well as obtaining the correct spacing of standing plasmons. Other inhomogeneous hydrodynamic theories do not achieve this. We also showed analytically an exact solution for a plasmon mode at the Kohn frequency in addition to one found in the Harmonic Potential Theorem. An open hydrodynamic theory was then developed based on this type of mode. Numerical application of Kohn Frequency Theorem theory was shown and the results were compared with other existing hydrodynamic theories.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Science
Science, Environment, Engineering and Technology
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Desmulliez, Marc P. Y. "Self-electro-optic-effect-device response analysis for optical computing." Thesis, Heriot-Watt University, 1995. http://hdl.handle.net/10399/767.
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Noot, Christopher David John. "The electro-optic properties of liquid crystalline materials for optical device applications." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416918.
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Mhaouech, Imed. "Étude du transport de charges dans le niobate de lithium massif et réalisation de fonctions électro-optiques dans le niobate de lithium périodiquement polarisé." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0032/document.
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Le premier volet de cette thèse est consacré à la modélisation des phénomènes de transport dans le LN. Partant d'une analyse critique des modèles de bande usuels, nous montrons leur inadéquation dans le cas du LN et nous proposons un modèle de saut basé sur la théorie des petits polarons. Nous étudions d'abord par simulation Monte-Carlo la décroissance d'une population de polarons liés NbLi4+ relaxant vers des pièges profonds FeLi3+. Nous montrons que les pièges FeLi3+ ont des rayons effectifs particulièrement grands, rayons qui augmentent encore à température décroissante, et limitent considérablement les longueurs de diffusion des polarons. Les résultats de simulations sont ensuite confrontés aux résultats expérimentaux obtenus par différentes techniques ; Absorption photo-induite, Raman, Enregistrement holographique et Pompe-sonde. Le deuxième volet de cette thèse est consacré aux applications électro-optiques dans le LN périodiquement polarisé (PPLN). Sous l’effet d’une tension électrique, l’indice de réfraction du PPLN est périodiquement diminué et augmenté, formant ainsi un réseau d’indice activable électriquement. Un premier composant utilisant l’effet électro-optique dans du PPLN a été développé et démontré expérimentalement. Dans ce composant, la lumière est défléchie sous l’effet de la tension électrique par le réseau d’indice. Ce déflecteur de Bragg atteint une efficacité de diffraction proche de 100% avec une faible tension de commande de l’ordre de 5 V. Un deuxième composant a également été proposé, où la lumière se propage perpendiculairement aux parois de domaines du PPLN. Dans cette configuration un réflecteur de Bragg électro-optique peut être réaliséThe first part of this thesis is devoted to the modeling of transport phenomena in the LN. From a critical analysis of the usual band models, we show their inadequacy in the case of LN and we propose a hopping model based on the theory of small polarons. We first study by Monte-Carlo simulation the population decay of bound polarons NbLi4+ in deep traps FeLi3+. We show that the traps (FeLi3+) have particularly large effective radii, which increase further at decreasing temperature, and considerably limit the diffusion lengths of the polarons. The results of simulations are then compared with experimental results obtained by different techniques; Light-induced absorption, Raman, Holographic storage and Pump-Probe. The second part of this thesis is devoted to electro-optical applications in the periodically poled LN (PPLN). Under the effect of an electrical voltage, the refractive index of the PPLN is periodically decreased and increased, thus forming an electrically activatable index grating. A first component using the electro-optical effect in PPLN has been developed and demonstrated experimentally. In this component, the light is deflected under the effect of the electrical voltage by the index grating. This Bragg deflector achieves a diffraction efficiency of close to 100% with a low drive voltage of the order of 5 V. A second component has also been proposed, where light propagates perpendicularly to the domain walls of the PPLN. In this configuration an electro-optic Bragg reflector can be realized
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Lam, Ping Koy, and Ping Lam@anu edu au. "Applications of Quantum Electro-Optic Control and Squeezed Light." The Australian National University. Faculty of Science, 1999. http://thesis.anu.edu.au./public/adt-ANU20030611.170800.
Full textAbstract:
In this thesis, we report the observations of optical squeezing from second harmonic generation (SHG), optical parametric oscillation (OPO) and optical parametric amplification (OPA). Demonstrations and proposals of applications involving the squeezed light and electro-optic control loops are presented.
¶
In our SHG setup, we report the observation of 2.1 dB of intensity squeezing on the second harmonic (SH) output. Investigations into the system show that the squeezing performance of a SHG system is critically affected by the pump noise and a modular theory of noise propagation is developed to describe and quantify this effect. Our experimental data has also shown that in a low-loss SHG system, intra-cavity nondegenerate OPO modes can simultaneously occur. This competition of nonlinear processes leads to the optical clamping of the SH output power and in general can degrade the SH squeezing. We model this competition and show that it imposes a limit to the observable SH squeezing. Proposals for minimizing the effect of competition are presented.
¶
In our OPO setup, we report the observation of 7.1 dB of vacuum squeezing and more than 4 dB of intensity squeezing when the OPO is operating as a parametric amplifier. We present the design criteria and discuss the limits to the observable squeezing from the OPO.We attribute the large amount of squeezing obtained in our experiment to the high escape efficiency of the OPO. The effect of phase jitter on the squeezing of the vacuum state is modeled.
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The quantum noise performance of an electro-optic feedforward control loop is investigated. With classical coherent inputs, we demonstrate that vacuum fluctuations introduced at the beam splitter of the control loop can be completely cancelled by an optimum amount of positive feedforward. The cancellation of vacuum fluctuations leads to the possibility of noiseless signal amplification with the feedforward loop. Comparison shows that the feedforward amplifier is superior or at least comparable in performance with other noiseless amplification schemes. When combined with an injection-locked non-planar ring Nd:YAG laser, we demonstrate that signal and power amplifications can both be noiseless and independently variable.
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Using squeezed inputs to the feedforward control loop, we demonstrate that information carrying squeezed states can be made robust to large downstream transmission losses via a noiseless signal amplification. We show that the combination of a squeezed vacuum meter input and a feedforward loop is a quantum nondemolition (QND) device, with the feedforward loop providing an additional improvement on the transfer of signal. In general, the use of a squeezed vacuum meter input and an electro-optic feedforward loop can provide pre- and post- enhancements to many existing QND schemes.
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Finally, we proposed that the quantum teleportation of a continuous-wave optical state can be achieved using a pair of phase and amplitude electro-optic feedforward loops with two orthogonal quadrature squeezed inputs. The signal transfer and quantum correlation of the teleported optical state are analysed. We show that a two dimensional diagram, similar to the QND figures of merits, can be used to quantify the performance of a teleporter.
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Kvavle, Joshua Monroe. "A System Level Approach to D-Fiber Electric Field Sensing." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd3155.pdf.
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Xu, Yang-Cheng, and 許洋誠. "Fabrication of GaAs electro-optic devices." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/04249158515403572834.
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Li, Wan-Jing, and 李婉靖. "Wide-Tunable Microring Devices by Electro-Optic Modulation." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/fxpet4.
Full textAbstract:
碩士國立臺北科技大學
光電工程系研究所
101
This thesis designs a new widely tunable integrated-optic microring filter. As the electric field is applied, the homeotropically-aligned positive Δε NLC with non-rubbed alignment layers is auto-realigned along the radial electric field produced by applying voltage on the ring electrodes. The uniform distributions of liquid crystal along the circular path of the microring waveguide make the propagating optical field at any position sense the maximum refractive index change of the liquid crystal. This effect makes the resonant wavelength of the produced microring filter be widely tuned by small applied voltages. The transmission spectrum for the TE and TM polarization are measured around the wavelength 1550nm. The dependence of the resonant wavelength on the applied voltage is discussed. The threshold voltages for both polarizations are 4.5V. When the applied voltage increases from 4.5V to 16V, the resonant wavelength has a red shift for TE mode and a blue shift for TM mode. The tuning ranges for TE and TM modes can be as large as 10.1nm and 23.1nm. The tuning rate for TE and TM modes are 0.903nm/V and -1.946nm/V. The features of the devices include low modulation voltage, wide wavelength tuning range, and fabrication compatibility.
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Chen, Po-Ting, and 陳柏廷. "Study of Electro-Optic Modulation on LiNbO3 Microdisk Devices." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/89mfs3.
Full textAbstract:
碩士國立臺北科技大學
光電工程系研究所
102
This thesis studies the use of electro-optic effect to modulate the resonant wavelength of the LiNbO3 microdisk. The device is fabricated by using ion implantation and chemical etching on the -z surface of LiNbO3 to produce undercut microdisk structure. The electrode on the top of the undercut microdisk cannot be wired out. In order to solve this problem, the suspended wire is produced by using optical lithography, vacuum coating, and chemical etching to connect the top electrode to the pad to form the electro-optically modulated LiNbO3 microdisk. The LiNbO3 microtoroid device is proposed to be produced by use the back-side surface thermal reflow process. Gravity and surface tension effect at the temperature, which approaches the melting point of the LiNbO3, are utilized to form the microtoroid structures. By The microtoroid characteristics are measured by using the tapered fiber coupling method. The 20μm-diameter microtoroid devices, which is treated for 9hrs using the back-side thermal reflow, has the quality factor as high as 5.9×104, which facilitates the optical second-harmonic generation on LiNbO3. The LiNbO3 elliptical microdisk device is important to achieve a directional emission microdisk laser. This work discusses the influence of the coupling position of the tapered fiber on the transmission spectra of elliptical microdisk. Experimental results show that the fiber coupling position decides whether the resonance modes can be excited. Small curvature radius on the elliptical microdisk makes the optical field in tapered fiber more easily couple into an elliptical microdisk due to its larger evanescent field range. As to the resonance wavelength and the free spectral range, the fiber position has little influence.
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Yi-HsiangHsu and 徐易翔. "Design of Lithium Niobate Electro-Optic and Corrugated Waveguide Devices." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/kf3y9r.
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碩士國立成功大學
微電子工程研究所
104
We have successfully fabricated a long-period waveguide gratings (LPWG) on lithium niobate (LiNbO3), of which cladding layer, waveguide core and phase gratings are all produced by proton exchange method. This device fabricated is a common rejection-band filter with grating pitch and grating length respectively set at 50 and 450µm. The spectral response of LPWGs are then evaluated by using optical spectrum analyzer. The result of TM transmission spectrum shows that a resonant dip with contrast of ~14.324dB occurred at wavelength λ of ~1567.04nm and FWHM of ~3.88nm are obtained. In order to analyze the dependence of resonance wavelength on temperature, a heater is placed under the device sample to control its operating temperature. Consequently, a phenomenon of blue-shift is observed as the temperature increases from RT to 50℃.
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Lin, Shih-ting, and 林士廷. "Fabrication and Carriers Transport Studying for Organic Electro-optic Devices." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/97873602838789296499.
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博士國立成功大學
光電科學與工程研究所
95
The main purpose of this dissertation is to study new fabrication processes and mechanism of carrier transport for organic optoelectronic devices. The investigations in this thesis include four parts: 1) study of polarized luminescence from organic material aligned by ion-beam-processed poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS), 2) polymer light-emitting diodes with thermal inkjet printed PEDOT:PSS, 3) excimer laser irradiation induced suppression of off-state leakage current in organic thin-film transistors (OTFTs), and 4) controllable threshold voltage OTFTs by O2 plasma treatment on surface of polyurethane dielectrics. The brief descriptions of four parts are as follows, (1) Study of polarized luminescence from organic material aligned by ion-beam-processed poly(3,4-ethylenedioxythiophene): polystyrenesulfonate Currently organic light-emitting diodes (OLEDs) have attracted a lot of interests as a new display technology. In the first part, we prepare a polarized OLEDs based on 4,4’-Bis[2-9(-ethyl-3-carbazoyl)vinylenyl]-1,1’-biphenyl (BECVB), which emitted polarized blue light, aligned by ion-beam-processed and rubbing-processed hole- injecting/-transport poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layer. A rubbing polyimide and photoalignment polyimide were also used to align BECVB. The dichroic ratios of linearly polarized photoluminescence of BECVB films aligning by various techniques were compared. (2)Polymer light-emitting diodes with thermal inkjet printed PEDOT:PSS In the second part, PEDOT:PSS films, prepared by inkjet-printing and spin-coating methods, have been studied using atomic force microscopy, micro-Raman spectroscopy, photoelectron spectroscopy, and four-point probe conductivity measurements. Electrical conductivity of the inkjet-printed film was enhanced by a factor of around 10 when compared to a spin-coating film. The improved conductivity was attributed to longer effective conjugation length of PEDOT chains in inkjet-printing PEDOT:PSS films as suggested by their micro-Raman spectroscopy. PEDOT:PSS films formed by the inkjet-printing method are appropriate for use as an anode for simplification of the fabrication process of polymer light-emitting diodes whose performance is about 1.2 cd/A. (3)Excimer laser irradiation induced suppression of off-state leakage current in organic transistors We report the suppression of the OFF-state leakage current and subthreshold swing (SS) in inkjet-printed poly(3-hexylthiophene) (P3HT) thin-film transistors with asymmetric work function source and drain electrodes. Indium-tin-oxide (ITO) material was used as source/drain electrodes and the source electrode was irradiated by KrF excimer laser. The dominant mechanisms for the suppressive IOFF could be attributed to the increase in the work function of ITO source irradiated by the excimer laser. Lower trap state density formed on the laser-irradiated source electrode. Holes could be easily injected into the channel at small lateral electric field resulting in smaller threshold voltage and SS. (4)Adjust threshold voltage device by O2 plasma treatment on polyurethane modified dielectrics Threshold voltage is one of the most important parameters for OTFTs. In the fourth part, we provide a new method to control the threshold voltage. A polyurethane (PU) films play the gate dielectric layers within OTFTs. The PU layer formed by spin coating and then the surface of PU treated under O2 plasma. Finally, organic polymer P3HT was inkjet-printed on the surface of PU to complete an OTFT. The threshold voltage of OTFTs increases with increasing the power of the O2 plasma. Additionally, the on-off ratio of OTFTs enhances three orders when the power of O2 plasma is above 500 W. Therefore, the method of O2 plasma treatment could effectively enhance the performance of OTFTs.
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翁國斌. "Electro — Optic Characteristics of Homogeneously Aligned ECB Color Liquid — Crystal Devices." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/26572744468119799618.
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碩士國立臺灣科技大學
高分子工程系
92
This study investigated the electro-optic characteristics of horizontal aligned ECB (Electrically Controlled Birefringence; ECB) color liquid crystal device. The experiment consisted of two parts. The first was, by changing the cell thickness (3μm, 5μm, 7μm, 10μm), incident wavelength (632.8nm, 514nm), and liquid crystal refraction anisotropy (E7( n)=0.223, ZLI-2293( n)=0.1322), to measure the electro-optic characteristics, including transmission, color shift, angle of view, and contrast. The second part used lithographic and etching technology to produce saw-tooth electrode shape on the ITO conductive layer of glass substrate, then measured the electro-optic characteristics, including transmission, angle of view, and contrast. Before electrified, the cell thickness and transmission under different liquid crystal refraction anisotropy were measured. The results showed that the long axis of liquid crystal molecule formed an angle with cross- polarized strip, and created varied hues of light with different transmission. When voltage was applied on cell with different thickness to reach maximum transmission, thicker cell required greater driving power to reach the maximum transmission, and the maximum transmission was even lower than the thin cell thickness. Thicker cell also required greater driving power to reach the same color as on thinner cell. In terms of the contrast under ECB display model, the contrast was about 20, and it would decrease as the cell thickness decreases. Use of lithographic and etching technology to produce saw-tooth electrode shape on the conductive layer of glass substrate could produce contrast as high as 140, and no reverse of gray scale on ± angle of view.
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Peng, Guan-Lun, and 彭冠綸. "Study of LiNbO3 Microdisk Devices with High-Efficiency Electro-Optic Modulation." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/q8rh3u.
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碩士國立臺北科技大學
光電工程系
106
This thesis proposes a novel high-efficiency electro-optical (EO) modulated lithium niobate (LiNbO3) microdisk resonant device with the characteristics of high-efficiency EO modulation and high quality factors by a newly designed circular electrode with a contracted diameter on the microdisk connected to a suspended wire structure. The traditional EO modulators on z-cut LiNbO3 used SiO2 as a buffer layer to isolate evanescent fields from the electrodes to reduce the light absorption of the metal electrodes for reduction of the insertion loss of the components. However, because the thickness of the LiNbO3 microdisk is only 0.4 μm, the evanescent field greatly extends to the periphery of the microdisk is large. Even the SiO2 layer with the thickness up to 0.8 μm still causes serious light absorption and hinders the resonance of the light field in the microdisk. In this thesis, the shrunk top electrode and the surrounding ring electrode were fabricated on and around the microdisk respectively, and the suspended wire is designed to connect the shrunk electrode to the electrode pad outside the microdisk. By shrinking the top electrode to the un-extended range of the fundamental mode light field, not only the absorption loss of the fundamental mode is reduced, but also the light field of the high-order radial modes can be absorbed such that the resonant light field is in a single mode radial mode. This electrode design can produce a high-efficiency electro-optical modulation of resonance wavelength when a voltage is applied, and at the same time, avoid light absorption of the metal electrode, which result in the optical loss of resonance modes and the degradation of quality factor. The experimental results show that the TE resonant mode of the 20 μm microdisk device has an intrinsic quality factor of 3.04×104 when no shrinkage electrode is added. After adding top electrodes of diameter 13 μm and 15 μm, the intrinsic quality factors were 2.17×104 and 1.51×104, respectively, with only a slight decrease. The electro-optical modulation rates are 28.23 pm/V and 29.20 pm/V for the microdisk devices with the diameter of the top electrode 13 μm and 15 μm. and the microdisk/electrode spacing 1 μm. Compared with the largest EO modulation rate in the current literature (3.41pm/V, Opt. Express 25(1), 124-129, 2017), the EO modulation rate of the microdisk device proposed in this thesis can be increased by up to 8.28 and 8.56 times. In the study of ZnO-diffusion-tuned LiNbO3 microdisk devices, the main purpose is to selectively tune the radial modes in the microdisk. Due to the light field of lower-order radial modes distributed on the microdisk periphery and that of higher-order radial modes extending toward the microdisk center, different radial modes could be affected by diffusing the ZnO film on the microdisk periphery and the microdisk center or edge of microdisk. The resultant refractive index distribution can be used to control the resonant characteristic of higher-order and lower-order radial modes. The results for TE mode shows that the tuning rates are -0.12nm/hr, -0.16nm/hr, and -0.18nm/hr for the ring diffusion region with width 2, 3 and 4 m, respectively. For the central diffusion region with the diameter of 10, 12 m, the tuning rates were -0.12nm/hr and 0.10nm/hr, respectively.
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Lin, Che-Yun. "Silicon integrated nanophotonic devices for on-chip optical interconnects." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5720.
Full textAbstract:
Silicon is the dominant material in Microelectronics. Building photonic devices out of silicon can leverage the mature processing technologies developed in silicon CMOS. Silicon is also a very good waveguide material. It is highly transparent at 1550nm, and it has very high refractive index of 3.46. High refractive index enables building high index contrast waveguides with dimensions close to the diffraction limit. This provides the opportunity to build highly integrated photonic integrated circuit that can perform multiple functions on the same silicon chip, an optical parallel of the electronic integrated circuit. However, silicon does not have some of the necessary properties to build active optical devices such as lasers and modulators. For Example, silicon is an indirect band gap material that can’t be used to make lasers. The centro-symmetric crystal structure in silicon presents no electro-optic effect. By contrast, electro-optic polymer can be engineered to show very strong electro-optic effect up to 300pm/V. In this research we have demonstrated highly compact and efficient devices that utilize the strong optical confinement ability in silicon and strong electro-optic effect in polymer. We have performed detailed investigations on the optical coupling to a slow light waveguide and developed solutions to improve the coupling efficiency to a slow light photonic crystal waveguides (PCW). These studies have lead to the demonstration of the most hybrid silicon modulator demonstrate to date and a compact chip scale true time delay module that can be implemented in future phased array antenna systems. In the future, people may be able to realize a photonic integrated circuit for optical communication or sensor systems using the devices we developed in our research.text
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Nevers, Corey A. "Electro-optic characterization of SrS-based alternating current thin-film electroluminescent devices." Thesis, 1999. http://hdl.handle.net/1957/34180.
Full textAbstract:
Two methods of electro-optically characterizing alternating-current thin-film electroluminescent
(ACTFEL) devices are investigated: photo-induced transferred charge
(PIQ) and luminescence (PIL), and subthreshold voltage-induced transferred charge (VIQ)
techniques. Both techniques provide information related to traps within the phosphor
layer. PIQ/PIL experiments monitor the transport of electrons and holes across the phosphor
layer which are photo-injected by a UV laser pulse. VIQ experiments monitor the
optical reset of traps ionized by bipolar subthreshold voltage pulses.
PIQ/PIL experiments are performed on three different SrS ACTFEL devices: ALE-deposited
SrS:Ce, sputter-deposited SrS:Cu, and undoped MOCVD-deposited SrS. From
the PIQ/PIL experiments, two distinct electron thresholds in the luminescent impurity
doped samples at ~0.8 (weak threshold) and ~1.2 MV/cm (strong threshold) are observed.
These thresholds are independent of the phosphor thickness, indicating that they
arise from a bulk property of the phosphor. The ~0.8 MV/cm weak threshold is attributed
to field emission of relatively shallow (~0.6 eV) electron-emitting bulk traps (e.g. cerium
or oxygen for SrS:Ce; a sulfur vacancy or oxygen for SrS:Cu). The ~1.2 MV/cm strong
threshold is ascribed to the onset of trap-to-band impact ionization. In contrast to electron
transport, PIQ/PIL studies reveal no hole transport in SrS doped with luminescent
impurities, although hole transport is observed for an undoped SrS ACTFEL device. The
lack of hole transport is attributed to the efficiency of hole capture in SrS doped with
luminescent impurities.
VIQ experiments are performed on the same SrS ACTFEL devices. VIQ trap energy
depths are estimated as ~0.1 eV for SrS:Ce; ~0.9 eV for SrS:Cu (with a capture cross-section
of ,~10�������cm��), and ~0.6 eV for undoped SrS. Tenative atomic identification of
traps responsible for these VIQ trends are: chlorine or a Ce shallow donor state for
SrS:Ce, a sulfur vacancy for SrS:Cu, and a sulfur vacancy or an oxygen isoelectronic trap
for undoped SrS.Graduation date: 2000
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Lee, Beom Suk 1974. "Novel EO polymer-based micro- and nano photonic devices for analog and digital communications." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-05-2673.
Full textAbstract:
Polymer-based electro-optical modulators are, generally, applicable to many fields but their applications to analog optical links and silicon photonic integrated circuits are specifically emphasized in this dissertation.
This dissertation aims to improve the linearity characteristics of polymer-based electro-optic modulators for their practical application in high speed analog optical links. Domain-inversion technique is employed to linearize a two-section Y-fed directional coupler modulator. The spurious free dynamic range as high as 119dB/Hz2/3 has been demonstrated with 11dB enhancement over the conventional Mach-Zehnder modulator at low frequency. For high speed modulation, a traveling wave electrode with low RF loss and large bandwidth is designed and installed in a linearized Y-fed directional coupler modulator. The spurious free dynamic range has been measured in the range of 110±3dB/Hz2/3 at 2~8GHz frequency.
For digital application of polymer-based electro-optic modulators, a hybrid silicon photonic crystal waveguide modulator was investigated with focus on size-reduction and electro-optic efficiency enhancement. The slow group velocity of photonic crystal waveguides promises two orders of magnitude size-reduction in device footprint compared with the conventional strip waveguide. Infiltration of an electro-optic polymer into the slot waveguide can infuse silicon with nonlinear optical properties. To actualize these benefits of a hybrid silicon photonic crystal waveguide modulator, nano-fabrication process was developed and optimized in this work.text
48
Chiou, Yu-Huei, and 邱玉蕙. "Optical Absorption Properties of Antisymmetric Coupled Wells and Their Application to Self-Electro-Optic-Effect Devices." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/31707600744022812676.
Full text
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Chang, Jui-Wen, and 張瑞文. "The investigation and development of the electro-optic quasi-phase matching photonic devices in lithium niobate." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/68308118895670368009.
Full textAbstract:
博士國立中央大學
光電科學與工程學系
102
Under the influence of the electric field in the direction of crystallographic z axis of the periodically poled lithium niobate (PPLN), a periodically varying permittivity along the crystallographic x axis will be produced. Such a device is called EO PPLN grating which can cause the reciprocal vector to compensate the phase mismatch between the incident extraordinary beam and its first order Bragg diffracted extraordinary beam in the device. In this dissertation, we developed a theoretical model to investigate and analyze the Bragg diffraction behavior of a Gaussian beam that interacts with such a device. This model can also be used to evaluate the performance of volume gratings in an optical system. For an electric field along the crystallographic y axis of the PPLN, the polarization state of the light which propagates along x axis in the PPLN can be modulated efficiently, and it has been explored and exploited to demonstrate efficient and fast polarization-mode converter (PMC). In this dissertation, we integrated two PPLN EO PMCs with a PPLN optical parametric gain medium in a monolithic LiNbO3 to achieve unique spectral manipulations in an optical parametric oscillator (OPO) system. With this kind of EO effect in, say an, annealed proton-exchanged PPLN waveguides, we report the design and experimental demonstration of electro-optically active TM-guided to TE-radiation mode converters. The devices demonstrated in this research have the potential for practical application. To further integrate the devices with other PPLN or APPLN structure with different optical functions in a monolithic LiNbO3 crystal, such devices can find many applications in optical communications or an electro-optic Q-switched and wavelength-tunable laser system.
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Mendes, James Kevin. "Sine burst waveform aging and electro-optic characterization of ALE ZnS:Mn ACTFEL devices for head-mounted active matrix displays." Thesis, 1997. http://hdl.handle.net/1957/34306.
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