Дисертації з теми "Bragg waveguide"
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1
Huang, Xuefeng. "Ion implanted optical waveguides and laser ablated Bragg waveguide gratings." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.364140.
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2
Wang, Xu. "Silicon photonic waveguide Bragg gratings." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45687.
Повний текст джерелаАнотація:
Silicon is the most ubiquitous material in the electronics industry, and is now expected to revolutionize photonics. In just over ten years, silicon photonics has become a key technology for photonic integrated circuits. By taking advantage of silicon-on-insulator (SOI) wafers and the existing complementary metal-oxide semiconductor (CMOS) fabrication infrastructure, silicon photonic chips are now being delivered with low cost and rapidly increasing functionality.
This thesis presents the integration of a fundamental optical device - Bragg grating - into SOI waveguides. Various types of waveguides and grating structures have been investigated. All designs are fabricated using CMOS foundry services. We have also explored various applications using the fabricated devices.
From the beginning, we focused on strip waveguide uniform gratings, as these are the most simple to design and fabricate. We have studied many design variations, supported by experimental results. In parallel, we have provided insight into practical issues and challenges involved with the design, fabrication, and measurement, such as the lithography effects, thermal sensitivity, and wafer-scale nonuniformity. We then introduce phase-shifted gratings that can achieve very high quality factors and be employed in various applications. We have also demonstrated sampled gratings and the Vernier effect in strip waveguides.
To obtain narrow-band gratings, we propose the use of a rib waveguide. We also propose a multi-period grating concept by taking advantage of the multiple sidewalls of the rib waveguide, to increases the design flexibility for custom optical filters. The wafer-scale data shows that rib waveguide gratings have better performance uniformity than strip waveguide gratings, and that the wafer thick- ness variation is critical. Additionally, we have demonstrated very compact Bragg gratings using a spiral rib waveguide.
Finally, we demonstrate slot waveguide Bragg gratings and resonators, which has great potential for sensing, modulation, and nonlinear optics. We have also developed a novel biosensor using a slot waveguide phase-shifted grating that has a high sensitivity, a high quality factor, a low limit of detection, and can interrogate specific biomolecular interactions.
3
Igata, Eishi. "Hydrocarbon vapour detection by waveguide-based sensor using Bragg grating reflector." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365443.
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4
Rogers, Helen L. "Direct UV-written Bragg gratings for waveguide characterisation and advanced applications." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/352169/.
Повний текст джерелаАнотація:
Direct UV writing is an established fabrication technique allowing channel waveguides and photonic circuits to be defined in a photosensitive glass via an inscription method. A related technique, direct grating writing, enables Bragg grating structures to be defined in an interferometric dual beam set up, with definition of Bragg grating planes achieved via the periodic modulation of the interference pattern between the beams. A decade of prior work investigating the technique has led to devices for use in sensing, telecommunications, lasing and amplification applications. A requirement for greater understanding of the propagation characteristics of the waveguides has been identified, in order to maximise the effciency and effectiveness of these devices. In this thesis, a propagation loss measurement technique and a wavelength-dependent dispersion measurement technique are presented. Both depend on the presence of integrated Bragg grating structures which enable the propagation characteristics of the waveguides to be investigated. The loss measurement technique involves measurement of the Bragg grating strength, whilst the dispersion measurement technique enables the effective refractive index of the waveguide to be inferred from a measurement of reflected central grating wavelength. Applications of both techniques in a variety of situations have been investigated, with devices fabricated for use in quantum technologies and cold matter experiments amongst those produced.
5
Odarenko, E. N., Y. V. Sashkova, and A. A. Shmat’ko. "Localized field enhancement in slow-wave modes of modified Bragg waveguide." Thesis, IEEE, 2017. https://openarchive.nure.ua/handle/document/18123.
Повний текст джерелаАнотація:
Modified scheme of Bragg reflection waveguide
with additional layers between the hollow core and cladding is
considered. Dispersion diagrams are calculated on the base of
dispersion equations solutions for ordinary and modified Bragg
waveguides. Slow-wave regimes are considered for both kinds of
structure. Electric field spatial distributions for localized slowwave
modes of Bragg reflection waveguide are obtained. It is
shown that modified scheme of Bragg waveguide provides the
enhanced localization of the surface modes field in the hollow
core. Therefore modified Bragg waveguide is the promising
electrodynamic system not only for laser-driven accelerators but
also for the vacuum electron devices where usual slow-wave
structures are unconvenient.
6
Sashkova, Y. V., and E. N. Odarenko. "The Effect of Additional Layers Parameters on the Modifided Bragg Waveguide Characteristics." Thesis, IEEE, 2017. https://openarchive.nure.ua/handle/document/18112.
Повний текст джерелаАнотація:
Bragg waveguide with additional layers between hollow core and periodic cladding is considered. On the base of dispersion equation solutions dispersion diagrams are obtained. The transversal spatial distributions of the electric field intensity are shown. The characteristics of Bragg waveguide respect to additional layer thickness and permittivity are considered. It is shown that increase of additional layers thickness results in increase of slow-waves number. Also field intensity decay in channel is reduced. Number of slow-waves increases respect to additional layers permittivity too. But distribution of the electric field intensity in the channel changes insignificantly. So one can tune additional layers parameters to get expected Bragg waveguide characteristics.
7
Hoffman, Galen Brandt. "Direct Write of Chalcogenide Glass Integrated Optics Using Electron Beams." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1322494007.
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8
Grieco, Andrew Lewis. "Discourse on the Characterization of Waveguide Distributed Bragg Reflectors for Application to Nonlinear Optics." Thesis, University of California, San Diego, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3624856.
Повний текст джерелаАнотація:
Precise characterization of waveguide parameters is necessary for the successful design of nonlinear photonic devices. This dissertation contains a description of methods for the experimental characterization of distributed Bragg reflectors for use in nonlinear optics and other applications. The general coupled-mode theory of Bragg reflection arising from a periodic dielectric perturbation is developed from Maxwell's equations. This theory is then applied to develop a method of characterizing the fundamental parameters that describe Bragg reflection by comparing the spectral response of Bragg reflector resonators. This method is also extended to characterize linear loss in waveguides. A model of nonlinear effects in Bragg reflector resonators manifesting in bistability is also developed, as this phenomenon can be detrimental to the characterization method. Specific recommendations are made regarding waveguide fabrication and experimental design to reduce sources of experimental error.
9
Tashtush, Aktham Atallah Mofleh. "Characterization of integrated Bragg gratings in silicon-on-insulator." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/7670/.
Повний текст джерелаАнотація:
Silicon-on-insulator (SOI) is rapidly emerging as a very promising material platform for integrated photonics.
As it combines the potential for optoelectronic integration with the low-cost and large volume manufacturing capabilities and they are already accumulate a huge amount of applications in areas like sensing, quantum optics, optical telecommunications and metrology.
One of the main limitations of current technology is that waveguide propagation losses are still much higher than in standard glass-based platform because of many reasons such as bends, surface roughness and the very strong optical confinement provided by SOI.
Such high loss prevents the fabrication of efficient optical resonators and complex devices severely limiting the current potential of the SOI platform.
The project in the first part deals with the simple waveguides loss problem and trying to link that with the polarization problem and the loss based on Fabry-Perot Technique.
The second part of the thesis deals with the Bragg Grating characterization from again the point of view of the polarization effect which leads to a better stop-band use filters.
To a better comprehension a brief review on the basics of the SOI and the integrated Bragg grating ends up with the fabrication techniques and some of its applications will be presented in both parts, until the end of both the third and the fourth chapters to some results which hopefully make its precedent explanations easier to deal with.
10
Li, Weizhuo. "Wavelength Multiplexing of MEMS Pressure and Temperature Sensors Using Fiber Bragg Gratings and Arrayed Waveguide Gratings." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1123972586.
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11
Lu, Peng. "Adaptive Control of Waveguide Modes in Two-Mode Fibers." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/65006.
Повний текст джерелаАнотація:
Few mode fibers and multimode fibers (MMFs) are traditionally regarded as unsuitable for important applications such as communications and sensing. A major challenge in using MMFs for aforementioned applications is how to precisely control the waveguide modes propagating within MMFs. In this thesis, we experimentally demonstrate a generic method for controlling the linearly polarized (LP) modes within a two-mode fiber (TMF). Our method is based on adaptive optics (AO), where one utilizes proper feedback signals to shape the wavefront of the input beam in order to achieve the desired LP mode composition.
In the first part of this thesis, we demonstrate the feasibility of AO-based mode control by using the correlation between the experimentally measured field distribution and the desired mode profiles as feedback for wavefront optimization. Selectively excitation of pure LP modes or their combinations at the distal end of a TMF are shown. Furthermore, we demonstrate that selective mode excitation in the TMF can be achieved by using only 5×5 independent phase blocks.
Afterwards, we extend our AO-based mode control method to more practical scenarios, where feedback signals are provided by all-fiber devices such as a directional fiber coupler or fiber Bragg gratings (FBGs). Using the coupling ratio of a directional coupler as feedback, we demonstrate adaptive control of LP modes at the two output ports of the directional coupler. With feedback determined by the relative magnitude of optical power reflected by a FBG and the transmitted power, selective excitations of the LP01 and the LP11 modes are experimentally shown.
As the final component of this thesis, we experimentally combine the AO-based mode control with time-division-multiplexing. By choosing reflected pulses with appropriate arrival time for mode control, we can selectively excite the LP11 mode at different FBG locations within the TMF, based on the ratio of optical signals reflected by FBGs in the TMF and the transmitted signal. Using two lasers set at the two FBG peak reflection wavelengths associated with the LP01 and the LP11 modes, we can accomplish AO-based mode control within a TMF by using only the reflection signals from the FBG. By using the ratio of the reflected signals of two lasers as feedback, we demonstrate selective excitation of almost pure LP01 or LP11 mode at the FBG location within the TMF.
The method developed in this thesis is generic and can be extended to many other applications using appropriately chosen feedback signals. It is possible to generalize the AO-based mode control method to MMF as well. This method may find important applications in MMF-based communication, sensing and imaging et. al. in the future.Ph. D.
12
Fevrier, Mickaël. "Couplage entre un guide d’onde diélectrique et un guide à plasmon de surface localisé : conception, fabrication et caractérisation." Thesis, Paris 11, 2012. http://www.theses.fr/2012PA112040/document.
Повний текст джерелаАнотація:
Ce travail de thèse présente une étude théorique, numérique et expérimentale de l’intégration sur un guide d’onde diélectrique de chaînes de nanoparticules d’or supportant des résonances « plasmon de surface localisé ». Les guides d’onde à plasmon de surface localisé procurent un confinement sub-longueur d’onde de la lumière, ce qui permet d’envisager la réalisation de composants optiques ultra-compacts. Cependant, leurs pertes optiques élevées restreignent leur application à de courtes distances de propagation, contrairement aux guides d’onde diélectriques. Une combinaison judicieuse des deux types de guide doit donc permettre de bénéficier de leurs avantages respectifs. Dans un premier temps, nous avons étudié théoriquement les propriétés des chaînes des nanoparticules grâce à un modèle analytique basé sur l’approximation de dipôles ponctuels couplés, que nous avons développé. Cette étude a permis de déterminer la forme et les dimensions des nanoparticules qui ont ensuite été introduites dans un logiciel de FDTD pour simuler le couplage entre la chaîne de nanoparticules et le guide diélectrique (SOI ou en Si3N4). De cette étude numérique, nous avons déduit les géométries des structures à fabriquer. Les structures réalisées ont été caractérisées à l’aide d’un banc de transmission résolue spectralement, mis en place pendant cette thèse, et d’un système de mesures en champ proche optique en collaboration avec le LNIO (Troyes). Pour la première fois, nous avons montré expérimentalement les propriétés d’une chaîne courte de nanoparticules intégrée sur un guide SOI, ainsi que le phénomène de guides couplés entre une chaîne longue de nanoparticules et un guide SOI. Une valeur record de la constante de couplage a été obtenue, et ce, aux longueurs d’onde des télécoms (proche infrarouge). L’énergie lumineuse transportée par le mode TE du guide SOI peut ainsi être entièrement transférée au guide plasmonique en 4 ou 5 nanoparticules, soit une distance de propagation de moins de 600 nm. Nous avons également étudié les propriétés de réseaux de Bragg à base de plasmon de surface localisé en confrontant les résultats de mesures de transmission résolue spectralement aux résultats théoriques d’un modèle analytique basé à la fois sur l’approximation de dipôle ponctuel en régime quasi-statique et la théorie des modes couplés. Ces travaux ouvrent la voie à des applications de pinces optiques, de capteurs ou de spaser, qui bénéficieront de l’intégration de nanoparticules métalliques dans les circuits photoniquesThis PhD work presents a theoretical, numerical and experimental study of the integration of a gold nanoparticle chain supporting "localized surface plasmon resonances" on a dielectric waveguide. The localized surface plasmon allows a sub-wavelength confinement of light which could lead to the achievement of ultra-compact optical components. However, the high level of optical losses restricts their application to short propagating distances unlike dielectric waveguides. A judicious combination of both types of guides should therefore allow taking profit of their respective advantages. Firstly, we have theoretically studied the properties of nanoparticles chains using an analytical model that we have developed following the coupled dipoles approximation. This has helped us to determine the shape and size of nanoparticles, which have been further used in a FDTD software, to simulate the coupling between the chain and the dielectric waveguide (SOI or Si3N4). Using this numerical study, we have deduced the geometries of structures to be fabricated. The realized structures have been characterized using a spectrally resolved transmission set-up, built during this thesis, and an optical near field measurement set-up (collaboration LNIO Troyes). For the first time, we have experimentally shown the properties of short nanoparticle chains integrated on a SOI waveguide as well as the existence of a coupled waveguide phenomenon between long nanoparticle chains and SOI waveguides. A record value has been obtained for the coupling constant at telecom wavelengths (near infrared). The light energy carried by the TE mode of the SOI waveguide can be completely transferred into the plasmonic waveguide via the first 4 or 5 nanoparticles of the chain, which means a distance of less than 600 nm. We have also studied the properties of Bragg gratings based on localized surface plasmon. Experimental results from spectrally resolved transmission measurements have been compared to theoretical results obtained from an analytical model based on the point dipole approximation in quasi-static regime, on one hand, and using the coupled mode theory, on the other hand. This work opens the way for applications to optical tweezers, sensors or spasers, which will benefit from the integration of metal nanoparticles in photonic circuits
13
Knappe, Frank. "Waveguide structuring and Bragg grating fabrication by ultraviolet light induced refractive index changes in photosensitive optical materials." Göttingen Cuvillier, 2006. http://d-nb.info/986384011/04.
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14
Hepp, Stefan [Verfasser]. "Quantum dot single-photon sources based on waveguide Bragg grating cavities for integrated quantum photonics / Stefan Hepp." München : Verlag Dr. Hut, 2021. http://d-nb.info/1240540167/34.
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15
Pochiraju, Sandhya. "Fabrication of Polymer Based Optical Devices for Communication and Sensing." UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_theses/270.
Повний текст джерелаАнотація:
Polymer waveguides present a potentially low cost alternative to electronics in communication systems. Polymers offer relatively straightforward and economical fabrication when compared to conventional materials. In this study, a fabrication process for Bragg gratings in polymer waveguides was developed. Waveguides were designed using finite-element analysis, patterned via e-beam lithography, and a detailed fabrication method was developed. Surface-Plasmon Resonance (SPR) is a widely accepted method for biological and chemical sensing. Measurement of bulk refractive index changes and specific surface binding is a crucial part in any biosensing. Design and fabrication of a novel self-referencing SPR sensor is described and its functionality is tested.
16
Oser, Dorian. "Integrated silicon photonics for quantum optics." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS455.
Повний текст джерелаАнотація:
La photonique silicium est un domaine prolifique de l’optique intégrée. Elle permet de miniaturiser de nombreuses fonctionnalités optiques, l’émission laser (en considérant les stratégies d’intégration hybride), la modulation électro-optique, le routage, la détection, pour les télécoms, les LIDAR ou la spectroscopie, la métrologie, les capteurs et laboratoires sur puce, toute en produisant à grande échelle avec une grande précision et à bas coût (grâce au technologies CMOS de la microélectronique). L’optique quantique, quant à elle, souffre d’une grande sensibilité aux vibrations et à l’environnement. Les montages optiques nécessitent stabilité, alignement parfait et un grand nombre d’éléments optiques, ce qui limite son développement à grande échelle. Inversement, tous ces aspects sont naturels en photonique intégrée. Le développement de la photonique quantique est ainsi susceptible de permettre l’implémentation à large échelle de systèmes de clés de cryptage pour les télécoms et le calcul quantique. Les prérequis de la photonique quantique sont globalement plus sévères que ceux de la photonique classique. La génération d’états quantiques nécessite notamment un niveau de réjection de la pompe de plus de 100 dB ; le niveau de bruit photonique ambiant sur la puce est également un facteur à soigner particulièrement dans la mesure où les paires de photons générées par les processus quantiques sont par principe de très faible puissance. Dans ce contexte, cette thèse aborde le développement de composants et de circuits pour la photonique quantique silicium. Le but est de générer des états intriqués en énergie-temps et de pouvoir les manipuler sur une puce. Cela va de la conception à l’utilisation des paires de photons, en passant par la fabrication des circuits intégrés optiques. La qualification des propriétés quantiques est aussi explorée afin de cerner les limitations de la plateforme silicium pour le domaine applicatif visé. L’esprit de ce travail est également de proposer des solutions restantes compatibles avec les canaux de télécommunications standard (ITU), de n’utiliser que des composants fibrés standards pour les connexions à réaliser, tout en restant compatibles avec les techniques de fabrication industrielle des grandes fonderies microélectroniques afin de permettre une future production à grand échelle des circuits photoniques quantiquesSilicon photonics is a dynamic research field of integrated optics. It allows to miniaturize numerous optical functionalities such as lasers, electro-optical modulators, routers, detectors, for telecom wavelengths, LIDAR, sensor, metrology or even spectroscopy, all while been able to propose large scale production high precision technologies. On another side, quantum optics suffers from difficulties to scale optical systems, requires extreme stability, perfect alignment, and many bulky optical elements, while solving these issues follows a natural path in integrated photonics. Development of integrated quantum photonics can thus open the door to cheap, powerful, and scalable systems for quantum cryptography, telecoms, and computation. In a significant way, quantum requirements are not the ones of classical circuits with respect to photonic components and circuits. The generation of quantum states indeed requires more than 100dB of pump laser rejection, while being able to manage ultra-low useful optical signals and get rid of on-chip optical noise. In this context, this thesis is dedicated to the study, dimension, realization, and characterization of silicon photonic components and circuits for quantum optics on a chip. The target goal is to generate entangled states in energy-time and manipulate them on chip. The qualification of the quantum properties is also explored to better understand the limitations of the silicon platform in the followed objectives. Another choice of this work is to stay in telecoms wavelength and aligned with the standard channels (ITU grid), to only use off-the-shelf components, all while been CMOS compatible and compliant with standard fabrication process, this to allow the possibility to produce on large scale
17
Chandra, Aveek. "Coupling 1D atom arrays to an optical nanofiber : Demonstration of an efficient Bragg atomic mirror." Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066582/document.
Повний текст джерелаАнотація:
Le couplage de guides d'ondes nanoscopiques et d'atomes froids a récemment ouvert de nouvelles voies de recherche. Le guide d'onde dans notre cas est une nanofibre qui confine la lumière transversalement à une échelle inférieure à la longueur d'onde. La lumière guidée présente un fort champ évanescent permettant une interaction atome-photon exaltée au voisinage de la nanofibre. Dans notre expérience, un nuage atomique froid est d'abord superposé à une nanofibre optique. Puis, en utilisant un piège dipolaire via le champ évanescent de la nanofibre, les atomes froids sont piégés à proximité de sa surface. Avec cette plateforme, nous avons obtenu des épaisseurs optiques élevées OD ~ 100 et de longues durées de vie ~ 25 ms en utilisant un schéma de piégeage qui préserve les propriétés internes des atomes. Une direction intéressante est alors d'explorer les effets collectifs résultant de l'ordre spatial des atomes. Lorsque la période du réseau est proche de la longueur d'onde de résonance, une réflexion de Bragg aussi élevée que 75% est observée. Cette réflexion dépend de la polarisation de la sonde par rapport aux réseaux atomiques - une signature de la chiralité dans les systèmes à guide d'ondes nanoscopiques. La possibilité de contrôler le transport de photons dans les guides d'ondes couplés à des systèmes de spin permettrait de nouvelles fonctionnalités pour les réseaux quantiques et l'étude d'effets collectifs résultant d'interactions à longue distanceThe coupling of cold atoms to 1D nanoscale waveguides have opened new avenues of research. The waveguide in our case is a nanofiber, which confines light transversally to a subwavelength scale. The guided light exhibits a strong evanescent field allowing enhanced atom-photon interaction in the vicinity of nanofiber. In our experiment, a cold atomic cloud is first interfaced with an optical nanofiber. By using an optical lattice in the evanescent field, the atoms are then trapped in 1D atomic arrays close to the nanofiber. In this platform, we reach high optical depth OD ~ 100 and long lifetimes ~ 25 ms by using a dual-color compensated trapping scheme that preserves the internal properties of atoms. In this thesis, we explore collective effects emerging from the spatial ordering of atoms. When the period of the lattice is made close to commensurate with the resonant wavelength, Bragg reflection, as high as 75%, is observed. The reflection shows dependency on orientation of the probe polarization relative to the atomic arrays - a chiral signature in nanoscale waveguide-QED systems. The ability to control photon transport in 1D waveguides coupled to spin systems would enable novel quantum networking capabilities and the study of many-body effects arising from long-range interactions
18
Wosinski, Lech. "Technology for photonic components in silica/silicon material structure." Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3556.
Повний текст джерелаАнотація:
The main objectives of this thesis were to develop a lowtemperature PECVD process suitable for optoelectronicintegration, and to optimize silica glass composition forUV-induced modifications of a refractive index in PECVDfabricated planar devices. The most important achievement isthe successful development of a low temperature silicadeposition, which for the first time makes it is possible tofabricate good quality low loss integrated components whilekeeping the temperature below 250oC during the entirefabrication process. Two strong absorption peaks thatappear at1.5 mm communication window due to N-H and Si-H bonds have beencompletely eliminated by process optimization. This openspossibilities for monolithic integration with other,temperature sensitive devices, such as semiconductor lasers anddetectors, or polymer-based structures on the common siliconplatform. PECVD technology for low loss amorphous silicon inapplication to SiO2/Si based photonic crystal structures hasbeen also optimized to remove hydrogen incorporated during thedeposition process, responsible for the porosity of thedeposited material and creation of similar to silica absorptionbands.
Change of the refractive index of germanium doped silicaunder UV irradiation is commonly used for fabrication of UVinduced fiber Bragg gratings. Here we describe our achievementsin fabrication of fiber Bragg gratings and their application todistributed sensor systems. Recently we have built up a laserlab for UV treatment in application to planar technology. Wehave demonstrated the high photosensitivity of PECVD depositedGe-doped glasses (not thermally annealed) even without hydrogenloading, leading to a record transmission suppression of 47dBin a Bragg grating photoinduced in a straight buried channelwaveguide. We have also used a UV induced refractive indexchange to introduce other device modifications or functions,such as phase shift, wavelength trimming and control ofpolarization birefringence.The developed low temperature technology and the UVprocessing form a unique technology platform for development ofnovel integrated functional devices for optical communicationsystems.
A substantial part of the thesis has been devoted tostudying different plasma deposition parameters and theirinfluence on the optical characteristics of fabricatedwaveguides to find the processing window giving the besttrade-off between the deposition rate,chamber temperatureduring the process, optical losses and presence of absorptionbands within the interesting wavelength range. The optimalconditions identified in this study are low pressure (300-400mTorr), high dilution of silane in nitrous oxide and high totalflow (2000 sccm), low frequency (380 KHz) RF source and high RFpower levels (800-1000 W).
The thesis provides better understanding of the plasmareactions during the deposition process. RF Power is the keyparameter for increasing the rate of surface processes so as toaccommodate each atomic layer in the lowest energy statepossible. All the process conditions which favor a moreenergetic ion bombardment (i.e. low pressure, low frequency andhigh power) improve the quality of the material, making it moredense and similar to thermal oxide, but after a certain pointthe positive trend with increasing power saturates. As theenergy of the incoming ion increases, a competing effect setsin at the surface: ion induced damage and resputtering.
Finally, the developed technologies were applied for thefabrication of some test and new concept devices for opticalcommunication systems including multimode interference (MMI)-based couplers/splitters, state-of-the-art arrayed waveguidegrating-based multi/ demultiplexers, the first Bragg gratingassisted MMI-based add-drop multiplexer, as well as moreresearch oriented devices such as a Mach-Zehnder switch basedon silica poling and a Photonic Crystal-based coupler.
Keywords:silica-on-silicon technology, PECVD, plasmadeposition, photonic integrated circuits, planar waveguidedevices, UV Bragg gratings, photosensitivity, arrayed waveguidegratings, multimode interference couplers, add-dropmultiplexers.
19
Zhang, Weifeng. "Silicon Photonics and Its Applications in Microwave Photonics." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36197.
Повний текст джерелаАнотація:
Thanks to its compatibility with the current CMOS technology and its potential of seamless integration with electronics, silicon photonics has been attracting an ever-increasing interest in recent years from both the academia and industry. By applying silicon photonic technology in microwave photonics, on-chip integration of microwave photonic systems could be implemented with improved performance including a much smaller size, better stability and lower power consumption. This thesis focuses on developing silicon-based photonic integrated circuits for microwave photonic applications. Two types of silicon-based on-chip devices, waveguide Bragg gratings and optical micro-cavity resonators, are designed, developed, and characterized, and the use of the developed devices in microwave photonic applications is studied.
After an introduction to silicon photonics and microwave photonics in Chapter 1 and an overview of microwave photonic signal generation and processing in Chpater2, in Chapter 3 a silicon-based on-chip phase-shifted waveguide Bragg grating (PS-WBG) is designed, fabricated and characterized, and its use for the implementation of a photonic temporal differentiator is experimentally demonstrated. To have a waveguide grating that is wavelength tunable, in Chapter 4 a tunable waveguide grating is proposed by incorporating a PN junction across the waveguide grating, to use the free-carrier plasma dispersion effect in silicon to achieve wavelength tuning. The use of a pair of wavelength-tunable waveguide gratings to form a wavelength-tunable Fabry-Perot resonator for microwave photonic signal processing is studied. Thanks to its electrical tunability, a high-speed electro-optic modulator, a tunable fractional-order photonic temporal differentiator and a tunable optical delay line are experimentally demonstrated. To increase the bandwidth of a waveguide grating, in Chapter 5 a linearly chirped waveguide Bragg grating (LC-WBG) is designed, fabricated and evaluated. By incorporating two LC-WBGs in two arms of a Mach-Zehnder interferometer (MZI) structure, an on-chip optical spectral shaper is produced, which is used in a photonic microwave waveform generation system based on spectral-shaping and wavelength-to-time (SS-WTT) mapping for linearly chirped microwave waveform (LCMW) generation. To enable the LC-WBG to be electrically tuned, in Chapter 6 a lateral PN junction is introduced in the grating and thus an electrically tunable LC-WBG is realized. By incorporating two tunable LC-WBGs in a Michelson interferometer structure, an electrically tunable optical spectral shaper is made. By applying the fabricated spectral shaper in an SS-WTT mapping system, a continuously tunable LCMW is experimentally generated.
Compared with a waveguide Bragg grating device, an on-chip optical micro-cavity resonator usually has a much smaller dimension, which is of help to increase the integration density and reduce the power consumption. Different on-chip optical micro-cavity resonators are studied in this thesis. In Chapter 7, an on-chip symmetric MZI incorporating multiple cascaded microring resonators is proposed. By controlling the radii of the rings, the MZI could be designed to have a spectral response with a linearly-varying free spectral range (FSR), which could be used in photonic generation of an LCMW, and to have a multi-channel spectral response with identical channel spacing, which could be used in the implementation of an independently tunable multi-channel fractional-order temporal differentiator. To further reduce the footprint of an optical micro-cavity resonator, in Chapter 8 an ultra-compact microdisk resonator (MDR) with a single-mode operation and an ultra-high Q-factor is proposed, fabricated and evaluated, and its use for the implementation of a microwave photonic filter and an optical delay line is experimentally demonstrated. To enable the MDR to be electrically tunable, in Chapter 9 an electrically tunable MDR is realized by incorporating a lateral PN junction in the disk. The use of the fabricated MDR in microwave photonic applications such as a high-speed electro-optic modulator, a tunable photonic temporal differentiator and a tunable optical delay line is experimentally demonstrated.
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Ouyang, George X. Yariv Amnon. "Bragg reflection in optical waveguides /." Diss., Pasadena, Calif. : California Institute of Technology, 2004. http://resolver.caltech.edu/CaltechETD:etd-01042005-110346.
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Wiesmann, Dorothea. "Bragg gratings in planar SiON waveguides /." [S.l.] : [s.n.], 2001. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13855.
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Dietz, Otto. "Linear and non-linear properties of light." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17474.
Повний текст джерелаАнотація:
Alle optischen Systeme haben den gleichen Zweck: Sie manipulieren Eigenschaften des Lichts, durch Interaktion mit Materie. In dieser Arbeit werden zwei wichtige Teilaspekte aus diesem Kontext untersucht, im linearen und im nicht-linearen Bereich. In Teil I werden die bekannten Bragg-Reflexionen in neuem Licht betrachtet. Bragg Reflexion findet statt, wenn Licht mit einem periodischen Medium interagiert. Die Bragg-Bedingung verknüpft den Gitterabstand in einem Kristall mit der Wellenlänge, die von ihm reflektiert wird. In dieser Arbeit werden die Bragg Reflexionen in gewellten Wellenleitern untersucht. Es wird gezeigt, dass die Bragg-Bedingung nicht ausreicht, um die Streuung in diesen Wellenleitern zu verstehen. Es wird numerisch und analytisch demonstriert, dass unebene Ränder eine neue Reflexionsbedingung schaffen, die über das einfache Bragg-Bild hinausgeht. Dieser Streueffekt, der Square Gradient Bragg-Mechanismus ist aus statistischen Streuansätzen bekannt. Er hängt mit der Krüummung des Randes zusammen und hat einen starken Einfluss auf die Wellenleitung in diesen Systemen. In dieser Arbeit wird die erste allgemeine Theorie für den Square Gradient Bragg Streumechanismus vorgestellt, die es ermöglicht, Voraussagen für einzelne Wellenleiter mit beliebig deformierten Rändern zu treffen. Eine weitere wichtige Eigenschaft des Lichts wird in Teil II dieser Arbeit untersucht: Die Verschränkung zwischen zwei Photonen. Verschränkung ist ein intuitiv nicht verständliches Phänomen, weil es in der uns umgebenden klassischen Welt kein Analogon hat. Insbesondere verletzt es unsere implizite Annahme eines lokalen Realismus, weil voneinander entfernte Teilchen scheinbar instantan miteinander wechselwirken können. In dieser Arbeit wird eine neue und verstimmbare Quelle für verschränkte Photonen entworfen. Die Photonenpaare werden in nicht-linearen Kristallen erzeugt, aber ihre Verschränkung wird rein geometrisch erzwungen. Dieser geometrische Ansatz erlaubt es, die Frequenz der Photonen einzustellen. Hier übertrifft diese neue Quelle ihre Vorgänger, die ausführlich besprochen werden. Die Verschränkung der erzeugten Photonen wird experimentell nachgewiesen.Any optical experiment, any optical technology is only about one thing: Manipulating the properties of light through interaction with matter. This thesis will address two important issues in this broad context, in the linear and in the non-linear regime. In Part I, the well-known Bragg reflection is revised. Bragg reflection takes place whenever light interacts with a periodic structure. The famous Bragg condition relates the lattice spacing in a crystal to the wavelength which is effectively reflected by that lattice. In this thesis the Bragg reflection in dielectric waveguides is investigated. It is shown that the Bragg condition is not sufficient to describe the scattering situation in waveguides with corrugated boundaries. It is demonstrated, analytically and numerically, that corrugated boundaries cause a new type of reflection condition, which goes beyond the Bragg picture. This scattering mechanism, the Square Gradient Bragg Scattering, is known from statistical scattering approaches. It is connected to the curvature of the boundary and has a strong influence on the wave propagation in these systems. Here the first general theory for Square Gradient Bragg Scattering is presented, which allows for making predictions for single corrugated waveguides with arbitrary boundaries. Another important property of light is investigated in Part II of this thesis: The entanglement of two photons. Entanglement is a counter-intuitive phenomenon, because it has no classical analogy. It especially violates our assumption of local realism, because distant particles seemingly act on each other instantaneously. In this thesis a new tunable and portable source of photon pairs is designed. The photon pairs are created in non-linear crystals, but their entanglement is enforced in a purely geometrical manner. This geometrical approach makes the setup tunable. This is where the new design supersedes its predecessor, which will be discussed in detail. The entanglement of the generated photons is demonstrated experimentally.
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Waugh, Peter Michael. "First order Bragg grating filters in silicon on insulator waveguides." Thesis, University of Surrey, 2008. http://epubs.surrey.ac.uk/843865/.
Повний текст джерелаАнотація:
The subject of this thesis is the design; analysis, fabrication and characterisation of first order Bragg Grating optical filters in Silicon-on-Insulator (SOI) planar waveguides. It is envisaged that this work will result in the possibility of Bragg Grating filters for use in Silicon Photonics. It is the purpose of the work to create as far as is possible flat surface waveguides so as to facilitate Thermo-Optic tuning and also the incorporation into rib-waveguide Silicon Photonics. The spectral response of the shallow Bragg Gratings was modelled using Coupled Mode Theory (CMT) by way of RSoft Gratingmod TM. Also the effect of having a Bragg Grating with alternate layers of refractive index 1.5 and 3.5 was simulated in order to verify that Silica and Silicon layered Bragg Gratings could be viable. A series of Bragg Gratings were patterned on 1.5 micron SOI at Philips in Eindhoven to investigate the variation of grating parameters with a) the period of the gratings b) the duty cycle (or mark to space ratio) of the gratings and c) the length of the region converted to Bragg Gratings (i.e. the number of grating period repetitions). One set of gratings were thermally oxidised at Philips in Eindhoven (this was to simulate the effects of oxidising Porous Silicon) and another set were ion implanted with Oxygen ions at the Ion Beam Facility, University of Surrey. The gratings were tested and found to give transmission minima at approximately 1540 nanometres and both methods of creating flat surfaces were found to give similar minima. Atomic Force Microscopy was applied to the grating area of the Ion as Implanted samples in the ATI, University of Surrey, which were found to have surface undulations in the order of 60 nanometres.
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Chan, Seong Phun. "Third order Bragg grating filters in silicon-on-insulator waveguides." Thesis, University of Surrey, 2005. http://epubs.surrey.ac.uk/842993/.
Повний текст джерелаАнотація:
The subject of this thesis is the design, analysis, fabrication and characterisation of third order Bragg grating optical filters on silicon-on-insulator (SOI) rib waveguides. New design guidelines for small cross sectional SOI waveguides have been proposed and described to address the issue of satisfying polarisation independence and single mode conditions simultaneously. This waveguide design will be used as a building block for the realisation of Bragg grating filters. The reflection spectral response of the deep Bragg grating operating in a third diffraction order on a single mode rib SOI waveguide has been studied theoretically using Floquet-Bloch Theory (FBT) developed in Politecnico di Bari, Italy in comparison with optical modelling software utilising Coupled Mode Theory (CMT). A series of Bragg gratings with different grating etch depths and lengths were fabricated at Southampton University to investigate the agreement between experimental results with theoretical predictions. The wavelength tuning capability of these Bragg grating filters in SOI waveguide structures were also investigated and implemented using the thermo-optic effect, through Joule heating of thin film aluminium heaters situated on top of the rib structure. The SOI rib waveguides with 1.5mum height are designed to exhibit polarisation independence and single mode operation. The Bragg grating filter is designed to operate at a wavelength of 1.55mum with a grating period of 689nm. The less rigorous fabrication tolerance of third order grating in comparison with that required by 228nm first order gratings is highly desirable only at the expense of slightly lower maximum reflectivity. The maximum reflectivity measurements of approximately 0.42 for third order grating are in agreement with theoretical prediction by FBT. The Bragg grating filters were thermally tuned to shift the Bragg resonance wavelength by up to 3.5nm with heater power of approximately 190mW. The tuning range of the filter is inhibited by the short lifetime of the heater caused by electromigration. At the time this work was carried out, this is the first demonstration of thermo-optic tuning through an integrated heating element, of third order Bragg grating filters based on small cross sectional SOI waveguide. The temperature sensitivity of the Bragg grating filters was analysed using a 2-D finite element method (FEM) and was consistent with the experimental results.
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Viallet, Benoît. "Conception d'un amplificateur optique à 1,3 (micron)m : spectroscopie de couches minces de LaF3 dopé Nd3+ et développement de procédés technologiques innovants." Toulouse 3, 2004. http://thesesups.ups-tlse.fr/21/.
Повний текст джерелаАнотація:
L'ion Nd3+ est un candidat potentiel pour réaliser un amplificateur optique à 1,3æm. Nous proposons une structure guide d'onde conçue à partir d'une couche mince de trifluorure de lanthane (LaF3) dopé néodyme (Nd3+) et intégrant un filtre par réseau de Bragg incliné. Nous avons caractérisé certaines propriétés spectroscopiques du LaF3:Nd3+ telles que la polarisation de l'émission à 1,3æm et l'effet de la concentration en ions Nd3+. La structure développée est originale de par l'utilisation d'un polymère pour réaliser les fonctions optiques passives et du LaF3:Nd3+ monocristallin comme matériau actif. Pour la fabriquer nous avons développé des technologies génériques permettant de réaliser des fonctions optiques bas coût : la nanoimpression, le polisciage et des traitements de surface. Finalement, nous avons modélisé l'amplificateur et déterminé les conditions à respecter pour optimiser le gain et le rendement du composantNd3+ ion is a potential candidate to realize an optical amplifier at 1. 3æm. A structure based on a thin layer of lanthanum trifluoride (LaF3) doped with neodymium (Nd3+) and including a tilted Bragg grating filter is proposed. Some spectroscopic parameters, such as the polarisation of 1. 3æm emission and the effects of Nd3+ concentration have been characterized. The proposed structure is inventive by some points, for exemple, the association of a polymer material to make passive optical functions and monocrystalline Nd3+: LaF3 as an active material. Generic technologies for the low cost fabrication of optical functions such nanoimprint lithography, poli-dicing, and surface treatments has been developed. The amplifier has been modelled and conditions to obtain a high gain and high efficiency have been defined
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Das, Bijoy Krishna. "Integrated optical distributed Bragg reflector and distributed feedback lasers in Er:LiNbO3 waveguides with photorefractive gratings." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969348541.
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Pissadakis, Stavros. "Bragg gratings in optical waveguides, glasses and thin oxide films induced by excimer laser radiation." Thesis, University of Southampton, 2000. https://eprints.soton.ac.uk/15896/.
Повний текст джерелаАнотація:
The purpose of this thesis is the fabrication and characterisation of sub-micron period (~500nm) Bragg relief grating reflectors in optical waveguide structures using interferometric excimer laser ablation. Furthermore, the work presented in this thesis describes investigation of the feasibility of the application of excimer laser grating micromachining for the fabrication of waveguide gratings which may be used as wavelength filters in the 1.5µm band for optical communications applications. For this purpose the following studies were carried out: (i) the ablation of sub-micron relief gratings on Tl+ ion-exchanged channel waveguides in Er/Yb-codoped B1664 glass, using 193nm excimer laser radiation and (ii) the ablation of sub-micron relief gratings in InOx and Ta2O5 thin oxide films overlaid on K+ ion-exchanged channel waveguides in BK-7 glass, using 248nm excimer laser radiation. For the waveguide gratings in Tl+ ion-exchanged Er/Yb-codoped B1664 glass reflectivities greater than 28dB were obtained from a 6mm long grating. Similarly, reflectivities greater than 4.7dB and 18dB were produced by 16mm long gratings in K+ ion-exchanged channel waveguides in BK-7 glass overlaid with InOx and Ta2O5 thin oxide films, respectively. In parallel, the ablation behavior of borosilicate glass using 193nm radiation and that of InOx and Ta2O5 thin oxide films using 248nm radiation were studied experimentally. Waveguide grating theory based on the study of the dispersion properties of multi-layer step-index planar and graded-index channel waveguides and on the scattering behaviour of grating structures in waveguides, has been developed and analysed. This theoretical background is employed to design the waveguide gratings used and to explain the experimental results obtained. Finally, the photorefractive properties of InOx and Ta2O5 thin oxide films under UV radiation are experimentally investigated
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Mak, William Chi Keung Electrical Engineering & Telecommunications Faculty of Engineering UNSW. "Coupled Solitary Waves in Optical Waveguides." Awarded by:University of New South Wales. Electrical Engineering and Telecommunications, 1998. http://handle.unsw.edu.au/1959.4/17494.
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Soliton states in three coupled optical waveguide systems were studied: two linearly coupled waveguides with quadratic nonlinearity, two linearly coupled waveguides with cubic nonlinearity and Bragg gratings, and a quadratic nonlinear waveguide with resonant gratings, which enable three-wave interaction. The methods adopted to tackle the problems were both analytical and numerical. The analytical method mainly made use of the variational approximation. Since no exact analytical method is available to find solutions for the waveguide systems under study, the variational approach was proved to be very useful to find accurate approximations. Numerically, the shooting method and the relaxation method were used. The numerical results verified the results obtained analytically. New asymmetric soliton states were discovered for the coupled quadratically nonlinear waveguides, and for the coupled waveguides with both cubic nonlinearity and Bragg gratings. Stability of the soliton states was studied numerically, using the Beam Propagation Method. Asymmetric couplers with quadratic nonlinearity were also studied. The bifurcation diagrams for the asymmetric couplers were those unfolded from the corresponding diagrams of the symmetric couplers. Novel stable two-soliton bound states due to three-wave interaction were discovered for a quadratically nonlinear waveguide equipped with resonant gratings. Since the coupled optical waveguide systems are controlled by a larger number of parameters than in the corresponding single waveguide, the coupled systems can find a much broader field of applications. This study provides useful background information to support these applications.
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Das, Bijoy Krishna [Verfasser]. "Integrated Optical Distributed Bragg Reflector and Distributed Feedback Lasers in Er:LiNbO3 Waveguides with Photorefractive Gratings / Bijoy Krishna Das." Aachen : Shaker, 2003. http://d-nb.info/1179039815/34.
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Barber, John P. "Fabrication of Hollow Optical Waveguides on Planar Substrates." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1568.pdf.
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Brown, Jeremiah. "DESIGN AND OPTIMIZATION OF NANOSTRUCTURED OPTICAL FILTERS." Doctoral diss., University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2825.
Повний текст джерелаАнотація:
Optical filters encompass a vast array of devices and structures for a wide variety of applications. Generally speaking, an optical filter is some structure that applies a designed amplitude and phase transform to an incident signal. Different classes of filters have vastly divergent characteristics, and one of the challenges in the optical design process is identifying the ideal filter for a given application and optimizing it to obtain a specific response. In particular, it is highly advantageous to obtain a filter that can be seamlessly integrated into an overall device package without requiring exotic fabrication steps, extremely sensitive alignments, or complicated conversions between optical and electrical signals. This dissertation explores three classes of nano-scale optical filters in an effort to obtain different types of dispersive response functions. First, dispersive waveguides are designed using a sub-wavelength periodic structure to transmit a single TE propagating mode with very high second order dispersion. Next, an innovative approach for decoupling waveguide trajectories from Bragg gratings is outlined and used to obtain a uniform second-order dispersion response while minimizing fabrication limitations. Finally, high Q-factor microcavities are coupled into axisymmetric pillar structures that offer extremely high group delay over very narrow transmission bandwidths. While these three novel filters are quite diverse in their operation and target applications, they offer extremely compact structures given the magnitude of the dispersion or group delay they introduce to an incident signal. They are also designed and structured as to be formed on an optical wafer scale using standard integrated circuit fabrication techniques. A number of frequency-domain numerical simulation methods are developed to fully characterize and model each of the different filters. The complete filter response, which includes the dispersion and delay characteristics and optical coupling, is used to evaluate each filter design concept. However, due to the complex nature of the structure geometries and electromagnetic interactions, an iterative optimization approach is required to improve the structure designs and obtain a suitable response. To this end, a Particle Swarm Optimization algorithm is developed and applied to the simulated filter responses to generate optimal filter designs.Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD
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Blais, Sebastien. "Design and realization of a Bragg grating prism on planar integrated optical waveguides for wideband photonic true time-delay beamforming." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/26856.
Повний текст джерелаАнотація:
This thesis presents a simulation and experimental study of a true time-delay (TTD) beamforming network using a Bragg grating prism on Ge-doped silica-on-silicon planar integrated optical waveguide for application in phased array antennas (PAA). The Bragg grating prism is designed and fabricated on planar optical waveguides and the true time-delay beamforming module is implemented using the fabricated waveguide Bragg grating prism and other photonic components.
When dealing with a remotely controlled PAA, the dispersive properties of a standard single mode fiber must be taken under consideration. To this effect, a simulation study has been carried out and is detailed in this thesis. The Bragg grating prism used in the beamformer is composed of chirped gratings of different lengths but of same total chirp in order to produce a true time-delay progression. Two modulation techniques are considered, single sideband (SSB) and double sideband (DSB) modulation. SSB modulation is shown to be well suited for broadband operations with little impact on the orientation of the mainlobe resulting from chromatic dispersion. (Abstract shortened by UMI.)
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Zeh, Christoph. "Polarization mode excitation in index-tailored optical fibers by acoustic long period gratings." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-127869.
Повний текст джерелаАнотація:
The present work deals with the development and application of an acoustic long-period fiber grating (LPG) in conjunction with a special optical fiber (SF). The acoustic LPG converts selected optical modes of the SF. Some of these modes are characterized by complex, yet cylindrically symmetric polarization and intensity patterns. Therefore, they are the guided variant of so called cylindrical vector beams (CVBs). CVBs find applications in numerous fields of fundamental and applied optics. Here, an application to high-resolution light microscopy is demonstrated. The field distribution in the tight microscope focus is controlled by the LPG, which in turn creates the necessary polarization and intensity distribution for the microscope illumination. A gold nanoparticle of 30 nm diameter is used to probe the focal field with sub-wavelength resolution. The construction and test of the acoustic LPG are discussed in detail. A key component is the piezoelectric transducer that excites flexural acoustic waves in the SF, which are the origin of an optical mode conversion. A mode conversion efficiency of 85% was realized at 785 nm optical wavelength. The efficiency is, at present, mainly limited by the spectral positions and widths of the transducer’s acoustic resonances. The SF used with the LPG separates the propagation constants of the second-order polarization modes, so they can be individually excited and are less sensitive to distortions than in standard weakly-guiding fibers. The influence of geometrical parameters of the fiber core on the propagation constant separation and on the mode fields is studied numerically using the multiple multipole method. From the simulations, a simple mode coupling scheme is developed that provides a qualitative understanding of the experimental results achieved with the LPG. The refractive index profile of the fiber core was originally developed by Ramachandran et al. However, an important step of the present work is to reduce the SF’s core size to counteract the the appearance of higher-order modes at shorter wavelengths which would otherwise spoil the mode purity. Using the acoustic LPG in combination with the SF produces a versatile device to generate CVBs and other phase structures beams. This fiber-optical method offers beam profiles of high quality and achieves good directional stability of the emitted beam. Moreover, the device design is simple and can be realized at low cost. Future developments of the acoustic LPG will aim at applications to fiber-optical sensors and optical near-field microscopyDiese Arbeit behandelt die Entwicklung und Anwendung eines akustischen langperiodischen Fasergitters (LPG) in Verbindung mit einer optischen Spezialfaser (SF). Das akustische LPG wandelt ausgewählte optische Modi der SF um. Einige dieser Modi weisen eine komplexe, zylindersymmetrische Polarisations- und Intensitätsverteilung auf. Diese sind eine Form der so genannten zylindrischen Vektor-Strahlen (CVBs), welche in zahlreichen Gebieten der wissenschaftlichen und angewandten Optik zum Einsatz kommen. In dieser Arbeit wird eine Anwendung auf die hochauflösende Lichtmikroskopie demonstriert. Die fokale Feldverteilung wird dabei durch die Auswahl der vom LPG erzeugten Modi, welche zur Beleuchtung genutzt werden, eingestellt. Als Nachweis wird die entstehende laterale Feldverteilung mithilfe eines Goldpartikels (Durchmesser 30 Nanometer) vermessen. Aufbau und Test des akustischen LPGs werden im Detail besprochen. Eine wichtige Komponente ist ein piezoelektrischer Wandler, der akustische Biegewellen in der SF anregt. Diese sind die Ursache der Umwandlung optischer Modi. Die maximale Konversionseffizienz betrug 85% bei 785 nm (optischer) Wellenlänge. Die Effizienz ist derzeit hauptsächlich durch die Lage der akustischen Resonanzfrequenzen des Wandlers und deren Bandbreite begrenzt. Die benutzte SF spaltet die Ausbreitungskonstanten von Polarisationsmodi zweiter Ordnung auf, sodass diese individuell angeregt werden können und weniger anfällig gegen über Störungen der Faser sind, als das bei gewöhnlichen, schwach führenden Glasfasern der Fall ist. Das zu Grunde liegende Brechzahlprofil des Faserkerns wurde von Ramachandran et al. entwickelt. Für diese Arbeit wurde jedoch die Ausdehnung des Profils verkleinert – ein erster Schritt um Anwendungen bei kürzeren optischen Wellenlängen zu ermöglichen. Es werden numerische Simulationen mit der Methode der multiplen Multipole zur Berechnung der Modenfelder und den zugehörigen Propagationskonstanten vorgestellt. Diese zeigen u. a. den starken Einfluss von geometrischen Veränderungen des Faserkerns. Basierend auf den Simulationsergebnissen wird ein einfaches Kopplungsschema für die Modi entwickelt, welches ein qualitatives Verständnis der experimentellen Ergebnisse ermöglicht. In Kombination bilden die SF und das LPG ein vielseitiges Gerät zur Erzeugung von CVBs und anderen Strahlen mit komplexer Phasenstruktur. Die Methode besticht durch hohe Qualität des Strahlprofils, stabile Abstrahlrichtung, einfachen Aufbau, elektronische Steuerbarkeit und geringe Materialkosten. Zukünftige Weiterentwicklungen des akustischen LPGs zielen auf die Anwendung in faseroptischen Sensoren und in der optischen Nahfeldmikroskopie ab
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Dietz, Otto Verfasser], Oliver [Akademischer Betreuer] [Benson, Achim [Akademischer Betreuer] Peters, and Wolfram [Akademischer Betreuer] Pernice. "Linear and non-linear properties of light : Square Gradient Bragg scattering in dielectric waveguides (Part I) and two-color folded-sandwich entangled photon pair source for quantum teleportation (Part II) / Otto Dietz. Gutachter: Oliver Benson ; Achim Peters ; Wolfram Pernice." Berlin : Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://d-nb.info/109733788X/34.
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Dietz, Otto [Verfasser], Oliver [Akademischer Betreuer] Benson, Achim [Akademischer Betreuer] Peters, and Wolfram [Akademischer Betreuer] Pernice. "Linear and non-linear properties of light : Square Gradient Bragg scattering in dielectric waveguides (Part I) and two-color folded-sandwich entangled photon pair source for quantum teleportation (Part II) / Otto Dietz. Gutachter: Oliver Benson ; Achim Peters ; Wolfram Pernice." Berlin : Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://d-nb.info/109733788X/34.
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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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Chang, Mei-Ju, and 張美如. "Development and Fabrication of Polymer Optical Waveguide and Bragg Reflection Waveguide." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/sw8nny.
Повний текст джерелаАнотація:
碩士國立虎尾科技大學
光電與材料科技研究所
93
In this thesis, we proposed a novel process, which incorporates with the photolithography and soft molding techniques, to fabricate the low loss polymer optical waveguides. In the meanwhile, a Bragg reflection waveguide, being a key component of optical add drop multiplexer (OADM), was also fabricated using such process. Single mode polymer optical waveguides were fabricated in terms of SU-8 and OG series polymer as the guiding layers, and good transmission characteristics were verified using the end-fire coupling and the cut-back techniques. The polymer Bragg grating reflection waveguide was fabricated in terms of OG polymer with stamping transfer techniques, and 350 nm grating depth can be easily obtained. The optical transmission characteristics were measured in terms of optical spectrum analyzer (OSA).
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Zhang, Haibin. "Bragg grating waveguide devices: Fabrication, optimization, and application." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=742336&T=F.
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Chang, Yu-Wei, and 張育瑋. "Fabrication of Polymer Nano-Bragg Grating Waveguide Devices." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/40288572502595876171.
Повний текст джерелаАнотація:
碩士南台科技大學
電子工程系
96
In this paper, we proposed a novel process, which incorporates with the soft molding and photolithography techniques. For the Bragg grating fabrication, the stamping transfer technique, incorporated with holographic interference technology, was used to transfer the grating to the PDMS soft film. And then, we use the PDMS polymer mold to fabricate Nano-Bragg polymer grating waveguide on the OG polymer by using of the soft molding and photolithography techniques. This technique has the advantages such as simple treatment, low loss and fabrication cost.
40
Kuo, Chin-Yi, and 郭晉譯. "Fabrication of Planer Polymer Waveguide Bragg Reflector Device." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/w37gs8.
Повний текст джерелаАнотація:
碩士國立虎尾科技大學
光電與材料科技研究所
98
In this thesis, we proposeda novel process, which incorporates with the photolithography and soft molding techniques, to fabricate Bragg reflection devices. Such devices are based on the planar polymer optical waveguides. For the Bragg reflection grating fabrication, the stamping transfer technique, incorporated with holographic interference technology, was used to transfer the grating from soft rubber mold to the OG polymer mold. Furthermore, we use the PDMS mold, being with the grating on it, and the UV epoxy to fabricate the planar type Bragg reflection waveguide devices. Use soft molding techniques to fabricate the low loss polymer optical waveguides and Large Scale production. The optical transmission characteristics were measured in terms of optical spectrum analyzer (OSA). The grating profiles of the devices were observed using SEM and AFM system.
41
Pan, Hung-yi, and 潘弘毅. "Liquid Crystal Infiltrated Waveguide with Distributed Bragg Reflectors." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/31418237869175029723.
Повний текст джерелаАнотація:
碩士國立中央大學
光電科學研究所
99
In this study, we propose the liquid crystal infiltrated waveguide with distributed Bragg reflector (DBR), which enables a dynamic control of tunable waveguide. The reorientation of the high susceptibility of liquid crystal (LC) molecular is successively achieved by varying external voltage to change the refractive index of the guiding core. Due to the electrical tuning of LC and the wavelength-selective property of DBR structure, the waveguide can be used as the tunable switching or the filter device. In the cladding of DBR structure, the multilayer stacks are formed by six pairs of Si3N4/SiO2, which is designed by the transfer matrix method. Also, we use the beam propagation method (BPM) to simulate the light behavior for different indices of LC in the guiding core. In experimental parts, we utilize three approaches to realize the characteristics of LC infiltrated waveguide with DBR. First of all, we use the polarized optical microscopy to observe and speculate the alignment of LC. Secondly, in the measurement of waveguide with different applied voltages, which is operating at 532nm, the waveguide can be served as an electrically optical switch with 28dB attenuation at 9Vrms. Finally, we measure the transmission spectrum of waveguides at visible wavelength range for varying applied voltages. The result shows that the LC in guiding core can change the transmission spectrum of the LC-filled waveguide. In the voltage-off state, the wavelength from 500nm to 660nm can be confined in the guiding core. As the applied voltage increases, the bandgap edge can be shift to the short wavelength. Specifically, while the external voltage is from 9Vrms to 20Vrms, the propagated light cannot be confined in the guiding core. At the external voltage of 30Vrms, we measured the all of visible wavelength that can be confined in the guiding core. The results of our simulation and the experiment measurement can help us to design and fabricate tunable devices based on the liquid crystal infiltrated waveguide with DBR.
42
Yang, Shang-Da, and 楊尚達. "A study of distributed Bragg reflector on LiNbO3 waveguide." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/09187502986217963852.
Повний текст джерелаАнотація:
碩士國立臺灣大學
光電工程學研究所
87
Distributed Bragg reflector (DBR) is found to be suitable as the cavity mirror of an erbium-doped LiNbO3 waveguide laser, because it may provide sufficiently high reflectivity, narrow bandwidth, and is capable of monolithically integrating with other integrated optical devices. Whereas, the traditional surface-relief DBR produced by etching grooves on the LiNbO3 waveguide usually exhibits very weak mode-index modulation, and therefore limited reflectivity. Significant improvements could be carried out if the Si-on-LiNbO3 structure is used, and the periodic corrugations are then introduced on the surface of silicon overlay. In this work, the novel features of the corrugated high index overlay (CHIO) DBR are theoretically investigated by the coupled-mode equations. Simulation results indicate that the coupling strength is sensitive to the Si-layer thickness, which is attributed to the transition of dominant mode intensity distribution from the LiNbO3 waveguide region up to the Si-layer. The optimum structural parameters for maximum effective reflectivity could be obtained after the insertion loss caused by mode profile mismatch is also taken into account. From which, a 3mm uniform DBR with peak reflectivity of 99.5% and bandwidth of 0.4nm could be anticipated. Finally, the spectral characteristics of various aperiodic CHIO DBR''s will be analyzed in terms of the fundamental matrix method, which demonstrate a wide variety of practical applications.
43
Chang, Hao-Yuan, and 張皓淵. "Low-loss Bragg Rectangular Waveguide at Low THz Region." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/g23uk7.
Повний текст джерела
44
Chia-Yu, Lin, and 林嘉瑜. "Investigation and Fabrication of Polymer Bragg Reflection channel Waveguide Devices." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/19891390255236578569.
Повний текст джерелаАнотація:
碩士南台科技大學
電子工程系
94
In this thesis, we proposed a novel process, which incorporates with the photolithography and soft molding techniques. For the Bragg grating fabrication, the stamping transfer technique, incorporated with holographic interference technology, was used to transfer the grating from soft rubber mold to the PDMS polymer mold. Then, we use the PDMS polymer mold to obtain the Bragg reflection waveguide on the OG polymer by using of the photolithography and soft molding techniques. This technique has the advantages such as simple treatment, low loss and fabrication cost. In the meanwhile, a Bragg reflection waveguide is applied for optical add/drop multiplexing (OADM) systems. Optical waveguide and grating were observed throgh SEM and AFM system. The observed results show the good performances of our devices. The optical transmission characteristics were measured in terms of optical spectrum analyzer (OSA).
45
Tsai, Meng-Chu, and 蔡孟舉. "A study of Asymmetric Polymer Waveguide Couplers with Bragg Reflectors." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/t7uz8r.
Повний текст джерелаАнотація:
碩士國立虎尾科技大學
光電與材料科技研究所
101
This study MEMS technology – based, using the photolithography process to fabricate waveguide channel, combined with soft lithography process technology in micro contact printing and replica molding technology, use of polydimethysiloxane ( PDMS) reprographic copying the waveguide channel to polymer materials, then with Holographic Interference Lithography to cycle adjustable and a large area production, making the bottom of the waveguide diffraction grating, the one waveguide channel have raster, another not of non-symmetrical structure, working conditions in conformity optical drop multiplexer works, then use of the above process technology can achieve the process simple and fast, and low cost price objective. In the experiment, we use the Field Emission Scanning Electron Microscope (FE-SEM) and Atomic Force Microscope (AFM) to observe the waveguide structure and the diffraction grating depth and period, finally using near-field coupling measurement technique to observe the polymer waveguide optical saturation intensity reflective element, then use Tunable Laser as light source and measuring the penetration waveguide grating spectrum and influence is reflected back through the reflection spectrum.
46
Luo, Guo-Yuan, and 羅國垣. "A Novel Metal/Multi-Insulator/Metal Waveguide Plasmonic Bragg Grating." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/99670738457642984203.
Повний текст джерелаАнотація:
碩士國立中央大學
光電科學研究所
99
A novel metal/multi-insulator/metal (MMIM) waveguide plasmonic Bragg grating is described in this thesis. The imaginary part of the mode index associated with an unperturbed MMIM waveguide can be decreased by inserting a low-index material in between the high-index core and metal region. It is shown that, as the width of the low-index region increases, the real and imaginary parts of the mode index decrease. On the other hand, as the width of the high- index region increases, the real part of the effective index increases but the imaginary part decreases. The design and analysis of the grating presented in this thesis are conducted using the finite-element-method-based numerical simulations. By optimizing the structure parameters, several design examples are obtained, including narrow-band/wide-band designs in the 1310-nm and 1550-nm communication windows. For the narrow-band cases, the full-width-at-half-maximum bandwidths are 15 nm and 2.9 nm for the 1310- and 1550-nm designs, respectively, while that of the 1550-nm wideband case is 174 nm. Time-average power vertexes are shown to occur in the stop band in particular for the narrow-band design examples. Moreover, power interchange exists between the silicon core and silica gap regions in the passband. The fabrication tolerance associated with the proposed Bragg grating is also studied. The Bragg wavelength exhibits a red shift if the period or silica gap width is larger than the designed value. For the wide-band design, fabrication errors in silica gap width of ±6 nm or in period of ±16 nm may raise the power transmission to about 10% in the stop band. An even larger error can finally cause the transmission spectrum to split into two stop bands. The fabrication tolerance associated with the wide-band design is found to be smaller than that in the narrow-band cases.
47
Yagnyukova, Mariya. "Modeling, Fabrication, and Characterization of a Bragg Slot Waveguide with a Cavity." Thesis, 2013. http://hdl.handle.net/1807/43347.
Повний текст джерелаАнотація:
This thesis encompasses a theoretical analysis, the fabrication, and optical characterization of a novel compact Bragg Slot Waveguide with a Cavity (BSWC). Strong light confinement in the low refractive index slot region formed by two silicon slabs on a silicon dioxide substrate [1] makes this structure useful for optofluidic, sensing, and optical trapping applications. The transmission spectrum of the BSWC can be engineered through the dimensional variations of the waveguide and through the refractive index change of the surrounding medium. BSWC is compact and can be integrated with various components on a chip for increased functionality.
The results in this thesis show a good agreement between analytical and experimental results, while emphasizing the increasing importance of atomic-scale imperfections as a result of fabrication on the nano-scale. The impact of the slot width, slab width, and the cavity length on the waveguide transmission spectrum is investigated.
48
Hsiao, Ming-Chuan, and 蕭明全. "Fabrication of Polymer Nano-Bragg Grating Waveguide Devices by Using MEMS." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/03870331925040728423.
Повний текст джерелаАнотація:
碩士南台科技大學
電子工程系
95
In this paper, we proposed a novel process, which incorporates with the photolithography and soft molding techniques. For the Bragg grating fabrication, the stamping transfer technique, incorporated with holographic interference technology, was used to transfer the grating from photoresist master mold to the PDMS soft rubber mold. Then, we use the PDMS polymer mold to obtain the Bragg reflection grating waveguide on the OG146 polymer by using of the photolithography and soft molding techniques. Therefore, it utilized Micro-Electro-Mechanical System (MEMS) to produce a channel optical waveguide molding and then it fabricated a optical waveguide Bragg filter by using mentioned soft molding technology. This technique has the advantages such as simple treatment, low loss and fabrication cost. Optical waveguide and grating were observed through SEM and AFM system. The observed results achieve the optimal diffraction efficiency. The optical transmission characteristics were measured in terms of optical spectrum analyzer (OSA).
49
Lin, Bai-Hao, and 林柏豪. "The Liquid Crystal Polymer With The Asymmetric Waveguide Bragg Grating Element." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/t7h3rw.
Повний текст джерелаАнотація:
碩士國立虎尾科技大學
光電與材料科技研究所
103
In this paper, a high molecular asymmetric waveguide structure to explore, with MEMS microfabrication technology, miniaturized waveguide structure and waveguide structure to make polymer materials, with this technology will be one of the waveguide channel masking, then use holographic interference lithography technology to produce Bragg grating on the waveguide, formed asymmetric waveguide structure, and by this technique, a Bragg grating having a waveguide structure in a residential section of LCD segments to the high refractive index to retrieve the two bands for the purpose. In this study, will be a field emission scanning electron microscope and atomic force microscopy to observe the waveguide structure and the diffraction grating depth and period, and with the amount of near-field measurement Technology in near-field coupling to observe the light saturation intensity, and finally to tunable lasers to measure the penetration of tunable Laser Spectroscopy and Spectral Reflectance element.
50
Chen, Chun-Yu, and 陳俊宇. "Higher-Order-Mode-Synthesized Waveguide Plasmonic Bragg gratings Using Semi-Analytical Approach." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/86257484449049561959.
Повний текст джерелаАнотація:
碩士國立中央大學
光電科學研究所
100
In this research, a semi-analytical approach is developed to facilitate the design of three-dimensional (3D) plasmonic waveguide Bragg gratings in metal/multi-insulator/metal (MMIM) configuration. When compared to the full-vector 3D numerical simulations, this method consumes less time and computational resources. In this method, the unit cell of the sinusoidally-width-modulated grating is approximated by a series of straight MMIM waveguides. By using the 3D finite-element method (FEM), the guided modes and their mode distributions/effective indices supported by the straight MMIM waveguide can be obtained. The corresponding 1D grating can then be constructed by replacing the straight waveguides with layers of the corresponding effective indices. It can then be conveniently analyzed by the transmission-line method, and the forbidden band(s) and the reflectance can be obtained accordingly. The semi-analytical approach is verified by the 3D full-vector numerical simulations based on the finite-difference-time-domain method and FEM for gratings synthesized using the 2nd-order mode. It is shown that the errors (absolute values) in the Bragg wavelength range from 0.0012 to 0.0399. This shows that the semi-analytical approach is valid and very reliable. For gratings using more unit cells and those synthesized using the 3rd-order mode, their corresponding spectra are also studied numerically and discussed in this thesis. A modified MMIM plasmonic Bragg grating which has a FWHM bandwidth of 12.7 nm centered at 1540 nm with a total length of < 9 is achieved. The transmission at the Bragg wavelength is 17.77%. Finally, the 3D MMIM waveguide grating synthesized using the semi-analytical approach is optimized using 3D full-vector numerical simulations incorporated with the simulated annealing algorithm. The optimized transmission spectrum of a 7710-nm long MMIM grating has a bandwidth of 42.6 nm centered at 1544 nm, and the transmittance in the pass band and stop band is about 80% and 4.496%, respectively. The final transmission spectrum fits well with the predefined spectrum.