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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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Wang, Xu. "Silicon photonic waveguide Bragg gratings." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45687.
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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.
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Li, Lifeng. "Application of diffraction grating theory to analysis and fabrication of waveguide gratings." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184388.
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This dissertation includes three separate studies of related waveguide grating phenomena. These studies deal with a numerical improvement of the integral method of diffraction grating theory, the theoretical analysis of waveguide gratings, and fabrication techniques for photoresist grating masks. The first topic addresses the acceleration of the convergence of the integral kernels. To improve the performance of the integral method for calculating diffraction grating efficiencies, the convergence of the integral kernels is studied. A nonlinear sequence transformation, Levin's u-transformation, is successfully applied to accelerate the convergence of the integral kernels. The computer execution time saving is significant. The application details and many numerical examples are given. The second subject is the ray optics theory of waveguide grating analysis. To establish a linkage between the analysis of diffraction gratings and the analysis of waveguide gratings, a new rigorous ray optics theory is developed. It takes into account phase changes on diffraction, multiple diffraction processes, depletion of the incident guided wave, and lateral shifts. A general characteristic equation that determines the waveguide grating attenuation (coupling) coefficient is derived. The symmetry properties of grating diffraction are applied to waveguide grating analysis for the first time. Lateral shifts of optical rays at a periodically corrugated interface similar to the Goos-Haenchen shift at a planar interface are suggested. The third subject is the in situ control of the development of photoresist grating masks. The existing method for monitoring and modeling photoresist grating development are modified and extended to monitoring and modeling photoresist grating mask development. Experimental examples, detailed theoretical considerations, and computer simulations are presented.
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Liu, Qing. "Design and fabrication of long-period waveguide gratings /." access full-text access abstract and table of contents, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b19887887a.pdf.
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Thesis (Ph.D.)--City University of Hong Kong, 2005."Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy" Includes bibliographical references.
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Koussi, Erieta-Katerina. "Micro patterning of complex Waveguide Resonant Gratings (WRG)." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSES027.
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Cette thèse de doctorat intitulée “Micro structuration de Réseaux Résonants complexes” étudie les dispositifs de détection optique, qui impliquent diverses techniques de photolithographie et outils de micro/nanotechnologie pour leur fabrication. Ces dispositifs, dans leur forme classique, consistent en un réseau de diffraction formé de lignes microscopiques gravées périodiquement sur une surface photosensible, qui est déposée sur une couche diélectrique, le guide d'onde. Les deux couches sont supportées sur un substrat. Pour activer les fonctions de détection, le réseau de diffraction doit être extrêmement sélectif, c'est-à-dire qu'il doit avoir la capacité de rejeter toutes les composantes spectrales reçues, en sélectionnant qu’une seule longueur d'onde pour la coupler au guide d'onde. Après le découplage, une réflexion dite résonante liée à sa très grande amplitude et sélectivité spectrale et angulaire se produit. Différents types de composants en fonction de l'application envisagée peuvent être réalisés sur différents types de substrats, matériaux ou géométries (plan, cylindrique). L'un des projets de cette thèse consiste à concevoir des WRG (Waveguide Resonant Gratings) sur les parois intérieures d'un tube pour coupler les modes TE et TM à l’intérieur du guide d’onde. La fabrication est réalisée par un masque de phase radial spécialement conçu, tandis que la fonction optique est mise en évidence en utilisant un miroir conique, capable de réfléchir la lumière de manière isotrope pour l'excitation des modes. De plus, des matériaux innovants peuvent être utilisés pour leur intégration dans des structures résonantes planaires. L'un des matériaux à l'étude est le dioxyde de vanadium (VO2), qui subit respectivement des transitions de phase de premier ordre (isolant vers métal) à basses et hautes températures. La fabrication d'un composé aussi délicat est complétée par deux méthodes de synthèse différentes, le dépôt par laser pulsé et la pulvérisation cathodique magnétron. La capacité d'induire une résonance en déclenchant thermiquement le dispositif est destinée aux applications de sécurité laser afin d'éviter l’endommagement lors d'une surchauffeThis PhD thesis entitled “Micro patterning of complex Waveguide Resonant Gratings (WRG)” studies the optical sensing devices, which involve various photolithography techniques and nanotechnology tools with clean room processes for their fabrication. These devices, in their classic form, consist of a diffraction grating formed by microscopic lines engraved periodically on a photosensitive surface, which is deposited on a dielectric layer, the waveguide. Both layers are supported on a substrate. To enable sensing functions, the diffraction grating must be extremely selective, i.e. it must have the ability to reject all the received spectral components, while selecting only one wavelength to couple it into the waveguide. After the out coupling, a reflection with a very large amplitude and great finesse occurs. Different types of components depending on the intended application can be produced on different types of substrates, materials or geometries (plane, cylindrical).One of the projects of this thesis engineers WRG on the interior walls of a tube to couple TE and TM modes into the waveguide. The fabrication is achieved by a specially designed radial phase mask, whereas the optical function is highlighted by the use of a conical mirror, able to reflect light isotropically for mode excitation. In addition, innovative materials can be used for their integration into flat WRG. One of the materials under study is the Vanadium Dioxide (VO2), which undergoes first-order phase transitions (Insulator to Metal) at low and high temperatures respectively. The fabrication of such a delicate compound is completed by two different synthesis methods, the Pulsed Laser Deposition and Magnetron Sputtering. The ability to induce resonance by thermally triggering the device is intended for laser safety applications to avoid damage during overheating
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MORIWAKI, Osamu, Ken-ichi SATO, Hiroshi HASEGAWA, and Shoji KAKEHASHI. "Formulation of Waveguide Connection for Waveband MUX/DEMUX Using Concatenated Arrayed-Waveguide Gratings." Institute of Electronics, Information and Communication Engineers, 2007. http://hdl.handle.net/2237/14992.
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Gargallo, Jaquotot Bernardo Andrés. "Advanced arrayed waveguide gratings: models, design strategies and experimental demonstration." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/74646.
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[EN] The present PhD thesis deals on the model, design and experimental demonstration of Arrayed Waveguide Grating (AWG) with advanced features. Firstly, building upon existing AWG formulations, design equations are provided, libraries developed and all this is experimentally validated with devices in Indium Phosphide (InP) and Silicon-on-insulator (SOI) technologies. Next, a model and experimental validation is reported for an Interleave-Chirped Arrayed Waveguide Grating (IC-AWG), which is able to process optical signals as WDM demultiplexer, polarization splitter and phase diversity component all in a single device. This device was fabricated and tested in InP technology. The second innovative AWG demonstrated in this thesis, a Reflective type (R-AWG), whose layout allows for tailoring the pass-band shape and to change the spectral resolution. A demonstration of design and fabrication for this device is provided in SOI technology. The last AWG with innovative concepts is one driven by Surface Acoustic Waves (AWG-SAW), where the spectral channels can be tuned by means of acousto-optic effect. The device was fabricated in Aluminium Gallium Arsenide (AlGaAs) technology, and measurements are provided to validate the concept and design flow. In parallel this thesis has resulted in the development of different AWG layouts for a wide number of (generic) technologies and foundries, coded into design libraries, of use in a de-facto standard software employed for the design of photonic integrated circuits. These design libraries have been licensed to the UPV spin-off company VLC Photonics S.L.[ES] La presente tesis se ha centrado en el modelado, diseño y demostración experimental del dispositivo Arrayed Waveguide Grating (AWG) con funcionalidades avanzadas. Primero, usando la formulación existente sobre AWGs se aportan ecuaciones y librerías de diseño, y se validan experimentalmente por medio de dispositivos fabricados en tecnologías de Indium Phosphide (InP) y Silicon-on-insulator (SOI). Después, se reporta un modelo y demostración experimental para un Interleave-Chirped Arrayed Waveguide Grating (IC-AWG), el cual es capaz de procesar señales ópticas como demultiplexor WDM, divisor de polarización y componente de diversidad de fase en un único dispositivo. Este dispositivo fue fabricado y probado en tecnología de InP. El segundo AWG innovador demostrado en esta tesis es de tipo Reflectante (R-AWG), cuyo diseño permite modificar la forma espectral del canal y cambiar su resolución espectral, incluyendo una demostración de diseño y fabricación de este dispositivo en tecnología de SOI. El último AWG que incluye conceptos innovadores es uno sintonizable por Acoustic Waves (AWGSAW), donde los canales espectrales pueden ser sintonizados por medio del efecto acusto-óptico. Dicho dispositivo fue fabricado en tecnología de Aluminium Gallium Arsenide (AlGaAs), y se han incluido medidas experimentales para validar el concepto y el flujo de diseño. En paralelo junto con esta tesis se han desarrollado diferentes diseños para el AWG en un amplio número de tecnologías (genéricas) y plataformas de fabricación, implementadas en unas librerías de diseño para uno de los softwares m¿as utilizados para el diseño de circuitos integrados ópticos, siendo actualmente el estándar de facto. Dichas librerías de diseño han sido licenciadas a la compañía VLC Photonics S.L., spin-off de la UPV.
[CAT] La present tesi ha estat centrada en el modelatge, disseny i demostració experimental del dispositiu Arrayed Waveguide Grating (AWG) amb funcionalitats avançades. Primer, usant la formulació existent sobre AWGs s'aporten equacions i llibreries de disseny, i es validen experimentalment per mitjà de dispositius fabricats en tecnologies de Indium Phosphide (InP) i Silicon-on-insulator (SOI). Després, es reporta un model i demostració experimental per a un Interleave-Chirped Arrayed Waveguide Grating (IC-AWG), el qual és capaç de processar senyals òptiques com demultiplexor WDM, divisor de polarització i component de diversitat de fase en un únic dispositiu. Aquest dispositiu va ser fabricat i provat en tecnologia de InP. El segon AWG innovador demostrat en aquesta tesi és de tipus Reflector (R-AWG), amb un disseny que permet modificar la forma espectral del canal i canviar la seua resolució espectral, incloent una demostració de disseny i fabricació d'aquest dispositiu en tecnologia de SOI. L'últim AWG que inclou conceptes innovadors és un sintonitzable per Acoustic Waves (AWG-SAW), on els canals espectrals poden ser sintonitzats per mitjà de l'efecte acusto-òptic. Aquest dispositiu va ser fabricat en tecnologia de Aluminium Gallium Arsenide (AlGaAs), i s'han inclòs mesures experimentals per validar el concepte i el flux de disseny. En paral.lel juntament amb aquesta tesi s'han desenvolupat diferents dissenys per al AWG en un ampli nombre de tecnologies (genèriques) i plataformes de fabricació, implementades en unes llibreries de disseny per a un dels programaris més utilitzats per al disseny de circuits integrats òptics, sent actualment l'estàndard de facto. Aquestes llibreries de disseny han estat llicenciades a la companyia VLC Photonics S.L., spin-off de la UPV.
Gargallo Jaquotot, BA. (2016). Advanced arrayed waveguide gratings: models, design strategies and experimental demonstration [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/74646
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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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Tsalamanis, Ioannis. "Applications of arrayed waveguide gratings in future hybrid access network topologies." Thesis, University of Essex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435595.
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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/.
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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.
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Rausch, Kameron Wade. "Broadband Arrayed Waveguide Grating Multiplexers on InP." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1319%5F1%5Fm.pdf&type=application/pdf.
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Akram, Nadeem. "Photonic devices with MQW active material and waveguide gratings : modelling and characterisation." Doctoral thesis, KTH, Mikroelektronik och Informationsteknik, IMIT, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-433.
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The research work presented in this thesis deals with modelling, design and characterisation of passive and active optical waveguide devices. The rst part of the thesis is related to algorithm development and numerical modelling of planar optical waveguides and gratings using the Method of Lines (MoL). The basic three-point central-di erence approximation of the δ2=δx2 operator used in the Helmholtz equation is extended to a new ve-point and seven-point approximation with appropriate interface conditions for the TE and TM elds. Di erent structures such as a high-contrast waveguide and a TM surface plasmon mode waveguide are simulated, and improved numerical accuracy for calculating the optical mode and propagation constant is demonstrated. A new fast and stable non-paraxial bi-directional beam propagation method, called Cascading and Doubling algorithm, is derived to model deep gratings with many periods. This algorithm is applied to model a quasi-guided multi-layer anti-resonant reecting optical waveguide (ARROW) grating polarizing structure. In the second part of the thesis, our focus is on active optical devices such as vertical-cavity and edge-emitting lasers. With a view to improve the bandwidth of directly modulated laser, an InGaAsP quantum well with InGaAlAs barrier is studied due to its favorable band o set for hole injection as well as for electron con nement. Quantum wells with di erent barrier bandgap are grown and direct carrier transport measurements are done using time and wavelength resolved photoluminescence upconversion. Semi-insulating regrown Fabry-Perot lasers are manufactured and experimentally evaluated for light-current, optical gain, chirp and small-signal performance. It is shown that the lasers having MQW with shallow bandgap InGaAlAs barrier have improved carrier transport properties, better T0, higher di erential gain and lower chirp. For lateral current injection laser scheme, it is shown that a narrow mesa is important for gain uniformity across the active region. High speed directly modulated DBR lasers are evaluated for analog performance and a record high spurious free dynamic range of 103 dB Hz2=3 for frequencies in the range of 1-19 GHz is demonstrated. Large signal transmission experiment is performed at 40 Gb/s and error free transmission for back-to-back and through 1 km standard single mode ber is achieved.QC 20100827
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Akram, Muhammad Nadeem. "Photonic devices with MQW active material and waveguide gratings : modelling and characterisation /." Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-433.
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Harper, Kevin Randolph. "Theory, Design, and Fabrication of Diffractive Grating Coupler for Slab Waveguide." Diss., CLICK HERE for online access, 2003. http://contentdm.lib.byu.edu/ETD/image/etd281.pdf.
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Lanker, Michael. "Arrayed waveguide gratings in indium phosphide using buried waveguides and optical space switches with high on-off ratio in silica /." Zürich, 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13602.
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Jones, Mark Lehi. "Design of normal-incidence waveguide-imbedded phase gratings for optical interconnects in multi-chip modules." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/15676.
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Lu, Peng. "Adaptive Control of Waveguide Modes in Two-Mode Fibers." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/65006.
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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.
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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/.
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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.
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Takahashi, Hiroshi, Toshio Watanabe, Ken-ichi Sato, Hiroshi Hasegawa, and Tomonobu Niwa. "Large Port Count Wavelength Routing Optical Switch Consisting of Cascaded Small-Size Cyclic Arrayed Waveguide Gratings." IEEE, 2012. http://hdl.handle.net/2237/21041.
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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.
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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.
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Santos, Cláudia Barros dos. "Laser a fibra dopada com Érbio com múltiplos comprimentos de onda e múltiplos regimes de operação simultâneos." Universidade Presbiteriana Mackenzie, 2011. http://tede.mackenzie.br/jspui/handle/tede/1399.
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Previous issue date: 2011-01-21In this work, we inserted two Arrayed Waveguide Gratings (AWGs), in an Erbium doped fiber ring cavity laser, where a single gain medium at room temperature can emit laser in multiples wavelengths, simultaneous and individualy controlled. The setup allowed us to check different functions in the ring cavity. Here we show emission in CW regime, Passive Mode-Locking, using Carbon Nanotubes as saturable absorbers and finally Active mode-locking at 7GHz, simultaneously.
Neste trabalho, fez-se a inserção de duas grades de difração matriciais com guias de onda, ou AWGs (Arrayed Waveguide Gratings) em uma cavidade laser de fibra dopada com Érbio, onde um único meio de ganho em temperatura ambiente pode gerar ação laser em múltiplos comprimentos de onda, com emissões simultâneas e controladas individualmente. A configuração utilizada permitiu o teste com diferentes regimes de operação simultâneos dentro da cavidade. Mostramos a possibilidade de emissão laser em regime CW, em regime de mode-locking passivo, com o uso de nanotubos de carbono como absorvedor saturável e, por último, em regime de modelocking ativo com uma freqüência de modulação de 7 GHz.
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Demori, Cláudia Barros dos Santos. "Laser de fibra dopada com érbio multifuncional." Universidade Presbiteriana Mackenzie, 2015. http://tede.mackenzie.br/jspui/handle/tede/1532.
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Previous issue date: 2015-08-25This work shows an Erbium doped-fiber Laser with many frequencies and many operation regimes based on integration of two paired arrayed waveguide gratings (AWGs) into a ring cavity. The AWGs are highlighted, since 2000, as key technology for multifrequencies lasers for optical communications, spectroscopy, image, astronomy and others applications. Fundamentally, gratings work splitting waveguide signal and since insertion in the cavity they allow simultaneous operating of tens of wavelength. We explore each one of these wavelength withing Erbium gain region, doing channels in different regimes of operation. These regimes may be continuous or pulsed. The advantage is that each channel may be modulated independently. Simultaneous operation with high repetition rates at 10 and 40 GHz were demonstrated, as continuous wave. The laser is stable, versatile and multifunctional. It is possible that more operating regimes, as passive mode-locking, be explored. We showed by this work efficient way to passive mode-locking by carbon nanotubes as saturable absorbers. Soon, the passive mode-locking is a potential regime for the demonstrated laser. As the new bi-dimensional materials, that look efficient for passive mode-locking and in the future, hybrid mode-locking, as graphene and black phosphor.
Esta tese trata de demonstrar um Laser de fibra dopada com Érbio com múltiplas frequências e múltiplos regimes de operação simultâneos baseados na integração de duas grades de difração pareadas (Arrayed Waveguide Gratings, AWGs) dentro de uma cavidade de laser de fibra. As AWGs são apontadas, desde o ano 2000, como tecnologia fundamental em lasers de múltiplas frequencias para as comunicações ópticas, para espectroscopia, imageamento, astronomia, e outras aplicações. Fundamentalmente, as grades funcionam como divisores do sinal óptico e quando inseridas dentro da cavidade de um laser de fibra permitem a operação simultânea de dezenas de comprimentos de onda. Neste trabalho, exploramos cada comprimento de onda, dentro da região de ganho do Érbio, com um regime de operação diferente. Esse regime pode ser pulsado ou contínuo. A vantagem do laser apresentado é que cada comprimento de onda é um canal que pode ser modulado de forma independente. Pôde-se demonstrar operação simultânea com regimes a altas taxas de repetição como 10 GHz e 40 GHz, assim como CW. O laser é estável, versátil e multifuncional. É possível que mais regimes de operação, como o regime de acoplamento de modos passivo sejam explorados. Mostramos ao longo deste trabalho maneiras eficientes de acoplar modos passivamente, utilizando nanotubos de carbono como absorvedores saturáveis, logo a técnica de acoplamento de modos passivo é um dos regimes em potencial para este laser. Assim como, o uso de novos materiais bidimensionais, que se mostram eficientes para o acoplamento de modos passivo e futuramente híbrido, como o grafeno e o fósforo negro.
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Jovanovic, N., N. Cvetojevic, C. Schwab, B. Norris, J. Lozi, S. Gross, C. Betters, et al. "Efficiently feeding single-mode fiber photonic spectrographs with an extreme adaptive optics system: on-sky characterization and preliminary spectroscopy." SPIE-INT SOC OPTICAL ENGINEERING, 2016. http://hdl.handle.net/10150/622807.
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High-order wavefront correction is not only beneficial for high-contrast imaging, but also spectroscopy. The size of a spectrograph can be decoupled from the size of the telescope aperture by moving to the diffraction limit which has strong implications for ELT based instrument design. Here we present the construction and characterization of an extremely efficient single-mode fiber feed behind an extreme adaptive optics system (SCExAO). We show that this feed can indeed be utilized to great success by photonic-based spectrographs. We present metrics to quantify the system performance and some preliminary spectra delivered by the compact spectrograph.
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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.
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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
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Greenwell, Andrew. "RIGOROUS ANALYSIS OF WAVE GUIDING AND DIFFRACTIVE INTEGRATED OPTICAL STRUCTURES." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4346.
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The realization of wavelength scale and sub-wavelength scale fabrication of integrated optical devices has led to a concurrent need for computational design tools that can accurately model electromagnetic phenomena on these length scales. This dissertation describes the physical, analytical, numerical, and software developments utilized for practical implementation of two particular frequency domain design tools: the modal method for multilayer waveguides and one-dimensional lamellar gratings and the Rigorous Coupled Wave Analysis (RCWA) for 1D, 2D, and 3D periodic optical structures and integrated optical devices. These design tools, including some novel numerical and programming extensions developed during the course of this work, were then applied to investigate the design of a few unique integrated waveguide and grating structures and the associated physical phenomena exploited by those structures. The properties and design of a multilayer, multimode waveguide-grating, guided mode resonance (GMR) filter are investigated. The multilayer, multimode GMR filters studied consist of alternating high and low refractive index layers of various thicknesses with a binary grating etched into the top layer. The separation of spectral wavelength resonances supported by a multimode GMR structure with fixed grating parameters is shown to be controllable from coarse to fine through the use of tightly controlled, but realizable, choices for multiple layer thicknesses in a two material waveguide; effectively performing the simultaneous engineering of the wavelength dispersion for multiple waveguide grating modes. This idea of simultaneous dispersion band tailoring is then used to design a multilayer, multimode GMR filter that possesses broadened angular acceptance for multiple wavelengths incident at a single angle of incidence. The effect of a steady-state linear loss or gain on the wavelength response of a GMR filter is studied. A linear loss added to the primary guiding layer of a GMR filter is shown to produce enhanced resonant absorption of light by the GMR structure. Similarly, linear gain added to the guiding layer is shown to produce enhanced resonant reflection and transmission from a GMR structure with decreased spectral line width. A combination of 2D and 3D modeling is utilized to investigate the properties of an embedded waveguide grating structure used in filtering/reflecting an incident guided mode. For the embedded waveguide grating, 2D modeling suggests the possibility of using low index periodic inclusions to create an embedded grating resonant filter, but the results of 3D RCWA modeling suggest that transverse low index periodic inclusions produce a resonant lossy cavity as opposed to a resonant reflecting mirror. A novel concept for an all-dielectric unidirectional dual grating output coupler is proposed and rigorously analyzed. A multilayer, single-mode, high and graded-index, slab waveguide is placed atop a slightly lower index substrate. The properties of the individual gratings etched into the waveguide's cover/air and substrate/air interfaces are then chosen such that no propagating diffracted orders are present in the device superstrate and only a single order is present outside the structure in the substrate. The concept produces a robust output coupler that requires neither phase-matching of the two gratings nor any resonances in the structure, and is very tolerant to potential errors in fabrication. Up to 96% coupling efficiency from the substrate-side grating is obtained over a wide range of grating properties.Ph.D.
Optics and Photonics
Optics and Photonics
Optics PhD
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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.
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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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Kakehashi, Shoji, Hiroshi Hasegawa, Ken-ichi Sato, Osamu Moriwaki, and Shin Kamei. "Analysis and Development of Fixed and Variable Waveband MUX/DEMUX Utilizing AWG Routing Functions." IEEE, 2009. http://hdl.handle.net/2237/14029.
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Lombardo, David. "Design and Fabrication of Suspended Waveguides With Photonic Grating Structures." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1591796311145344.
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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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Rabady, Rabi Ibrahim. "Waveguide grating mirror for laser resonators." Connect to online resource - WSU on-site and authorized users, 2003.
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Ng, Sandy. "Ultrafast laser written bulk waveguides and gratings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/MQ53441.pdf.
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Ehrlich, Jeffrey Ellis. "Nonlinear grating structures in indium antimonide waveguides." Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184914.
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This dissertation describes various nonlinear grating coupling phenomena in InSb waveguides. InSb exhibits an opto-thermal, diffusive nonlinearity at 9.6μm. This nonlinearity strongly modifies the growth of a guided wave via the grating coupling of an incident, Gaussian signal. In particular, optical limiting and bistability in the coupled power were demonstrated for a detuned grating coupler. The limits on the detunings were also investigated. The experimental results showed qualitative agreement with a theory based upon a diffusive nonlinearity in the grating coupling process. Also demonstrated and theoretically explained was a new form of "butterfly" bistability in the output coupled signal from a nonlinear waveguide. In this situation, nonlinear interference effects in the substrate modified the proportion of power outcoupled into the cover and the substrate. The effects of a thermal nonlinearity on the response of a distributed feedback grating (DFB) were also studied. The DFB reflection response of an incident guided wave was modified either by varying the power of the incident guided wave or that of a second guided wave. Also, the effects of the DFB reflection were shown to enhance the bistable input grating coupling process by providing an additional feedback. This enhancement resulted in a smaller incident switching power required to obtain bistability in the input coupler.
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Lin, John Chin-Hsiang. "Integrated optical sensors using waveguide grating reflectors." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239280.
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Chan, Gordon Siu Fan. "Vertical grating assisted coupling between waveguide layers." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282414.
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Calonico-Soto, Alicia. "Influence of optical crosstalk on WDM all-optical network design." Thesis, University of Essex, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327077.
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Fernández, Vicente Juan. "Reconfigurable Reflective Arrayed Waveguide Grating on Silicon Nitride." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/165783.
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[ES] La presente tesis se ha centrado en el modelado, diseño y demonstración experimental por primera vez del dispositivo Reconfigurable Reflective Arrayed Waveguide Grating (R-RAWG). Para la consecución de este dispositivo que tiene posibilidades de uso en la espectrometría, una plataforma de nitruro de silicio llamada CNM-VLC se ha usado, ya que este material permite operar en un gran ancho de banda. Esta plataforma posee ciertas limitaciones y los elementos necesarios para el funcionamiento de este dispositivo tenían un performance bajo. Por ello, se ha desarrollado y validado una metodología que ha permitido obtener mejores divisores. Además, se ha diseñado un inverted taper que ha mejorado considerablemente el acoplo de luz al chip. Esto ha sido gracias a un exhaustivo análisis de opciones existentes en la literatura que también ha permitido escoger la mejor opción para realizar un espejo reconfigurable en la plataforma sin cambiar ni añadir ningún proceso de fabricación. Se han demostrado espejos reconfigurables gracias a utilizar divisores ópticos realimentados y también se ha desarrollado códigos que predicen el comportamiento del dispositivo experimentalmente. Con todo el trabajo realizado, se ha diseñado un R-RAWG para que pudiera operar en un gran ancho de banda y que los actuadores de fase no tuvieran peligro de estropearse. También se ha desarrollado un código para el modelado del R-RAWG que permite imitar la fabricación de estos dispositivos y que, gracias a esto, se ha desarrollado un método o algoritmo llamado DPASTOR, que usa algoritmos usados en machine learning, para optimizar la respuesta con tan sólo la potencia óptica de salida. Finalmente, se ha diseñado una PCB para poder conectar eléctricamente el chip fotónico y se ha desarrollado un método de medida que ha permitido tener una respuesta estable consiguiendo demostrar multitud de respuestas de filtros ópticos con el mismo dispositivo.[CAT] La present tesi s'ha centrat en el modelatge, disseny i demonstració experimental per primera vegada del dispositiu Reconfigurable Reflective Arrayed Waveguide Grating (R-RAWG). Per a la consecució d'aquest dispositiu que té possibilitats d'ús en l'espectrometria, una plataforma de nitrur de silici anomenada CNM-VLC s'ha usat ja que aquest material permet operar en una gran amplada de banda. Aquesta plataforma posseeix certes limitacions i els elements necessaris per al funcionament d'aquest dispositiu tenien un performance baix. Per això, s'ha desenvolupat i validat una metodologia que ha permés obtindre millors divisors i també, gràcies als processos de fabricació, s'ha dissenyat un acoplador que ha millorat considerablement l'acoble de llum al xip. Això ha sigut gràcies a un exhaustiu analisis d'opcions existents en la literatura que també ha permés triar la millor opció per a realitzar un espill reconfigurable en la plataforma sense canviar ni afegir cap procés de fabricació. S'han demonstrat espills reconfigurables gràcies a utilitzar divisors realimentats i també s'ha desenvolupat codis que prediuen el comportament del dispostiu experimentalment. Amb tot el treball realitzat, s'ha dissenyat un R-RAWG fent ús de determinades consideracions perquè poguera operar en una gran amplada de banda i que els actuadors de fase no tingueren perill de desbaratar-se. També s'ha desenvolupat un codi per al modelatge del R-RAWG que permet imitar la fabricació d'aquests dispositius i que, gràcies a això, s'ha desenvolupat un mètode o algorisme anomenat DPASTOR, que usa algorismes usats en machine learning, per a optimitzar la resposta amb tan sols la potència òptica d'eixida. Finalment, s'ha dissenyat una PCB per a poder connectar elèctricament el xip fotònic i s'ha desenvolupat un mètode de mesura que ha permés tindre una resposta estable aconseguint demostrar multitud de respostes de filtres òptics amb el mateix dispositiu.
[EN] This thesis is focused on the modelling, design and experimental demonstration for the first time of Reconfigurable Reflective Arrayed Waveguide Grating (R-RAWG) device. In order to build this device, that can be employed in spectrometry, a silicon nitride platform termed CNM-VLC has been chosen since this material allows to operate in broad range of wavelengths. This platform has the necessary elements, but some limitations because the operation of this device had a low performance. Therefore, a methodology has been developed and validated, which has allowed to obtain better splitters. Also an inverted taper has been designed, which has considerably improved the coupling of light to the chip. This has been possible thanks to an exhaustive analysis of existing options in the literature, that has allowed choosing the best option to make a reconfigurable mirror on the platform without changing or adding new manufacturing steps. Reconfigurable mirrors have been demonstrated by using feedback splitters. Furthermore, codes have been developed to predict the behaviour of the actual device. With all the work done, a R-RAWG has been designed by using certain considerations so that it can operate over a broad wavelength range and the phase actuators are not in danger of being damaged. A code has also been developed for the modelling of the R-RAWG, which allows manufacturing imperfections to be considered, thanks to this, a method or algorithm called DPASTOR has been developed. DPASTOR resembles machine learning to optimise the response by just using the optical output power. Finally, a PCB and an assembly with the chip interconnected to it have been made and designed. Moreover, a measurement method has been developed, which has made it possible to have a stable response and to demonstrate a multitude of optical filter responses with the same device.
Fernández Vicente, J. (2021). Reconfigurable Reflective Arrayed Waveguide Grating on Silicon Nitride [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/165783
TESIS
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Cleary, Justin. "Surface Plasmon Hosts for Infrared Waveguides and Biosensors, and Plasmons in Gold-Black Nano-Structured Films." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3562.
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Applications of surface plasmon polaritons (SPPs) have thus far emphasized visible and near-infrared wavelengths. Extension into the long-wave infrared (LWIR) has numerous potential advantages for biosensors and waveguides, which are explored in this work. A surface plasmon resonance (SPR) biosensor that operates deep into the infrared (3-11 µm wavelengths) is potentially capable of biomolecule recognition based on both selective binding and characteristic vibrational modes. The goal is to operate such sensors at wavelengths where biological analytes are strongly differentiated by their IR absorption spectra and where the refractive index is increased by dispersion, which will provide enhanced selectivity and sensitivity. Potentially useful IR surface plasmon resonances are investigated on lamellar gratings formed from various materials with plasma frequencies in the IR wavelength range including doped semiconductors, semimetals, and conducting polymers. One outcome of this work has been the demonstration of a simple analytic formula for calculating the SPP absorption resonances in the angular reflectance spectra of gratings. It is demonstrated for Ag lamellar gratings in the 6-11 µm wavelength range. The recipe is semi-empirical, requiring knowledge of a surface-impedance modulation amplitude, which is found here by comparison to experiment as a function of the grating groove depth and the wavelength. The optimum groove depth for photon-to-SPP energy conversion was found by experiment and calculation to be ~10-15% of the wavelength. Hemicylindrical prism couplers formed from Si or Ge were investigated as IR surface plasmon couplers for the biosensor application. Strong Fabry-Perot oscillations in the angular reflectance spectra for these high index materials suggest that grating couplers will be more effective for this application in the LWIR. A variety of materials having IR plasma frequencies were investigated due to the tighter SPP mode confinement anticipated in the IR than for traditional noble metals. First doped-Si and metal silicides (Ni, Pd, Pt and Ti) were investigated due to their inherent CMOS compatibility. Rutherford backscattering spectroscopy, x-ray diffraction, scanning electron microscopy, secondary ion mass spectrometry and four point probe measurements complemented the optical characterization by ellipsometry. Calculation of propagation length and mode confinement from measured permittivities demonstrated the suitability for these materials for LWIR SPP applications. Semimetals were also investigated since their plasma frequencies are intermediate between those of doped silicon and metal silicides. The semimetal antimony, with a plasma frequency ~80 times less than that of gold was characterized. Relevant IR surface plasmon properties, including the propagation length and penetration depths for SPP fields, were determined from optical constants measured in the LWIR. Distinct resonances due to SPP generation were observed in angular reflection spectra of Sb lamellar gratings in the wavelength range of 6 to 11 µm. Though the real part of the permittivity is positive in this range, which violates the usual condition for the existence of bound SPP modes, calculations based on experimental permittivity showed that there is little to distinguish bound from unbound SPP modes for this material. The SPP mode decays exponentially away from the surface on both sides of the permittivity sign change. Water is found to broaden the IR plasmon resonances significantly at 9.25 micron wavelength where aqueous extinction is large. Much sharper resonances for water based IR SPR biosensor can be achieved in the 3.5 to 5.5 µm range. Nano-structured Au films (Au-black) were investigated as IR absorbers and possible solar cell enhancers based on surface plasmon resonance. The characteristic length scales of the structured films vary considerably as a function of deposition parameters, but the absorbance is found to be only weakly correlated with these distributions. Structured Au-black with a broad range of cluster length scales appear to be able to support multiple SPP modes with incident light coupling to the corrugated surface as seen by photoelectron emission microscopy (PEEM) and SPR experiments, supporting the hypothesis that Au-black may be a suitable material for plasmon-resonance enhancement solar-cell efficiency over the broad solar spectrum.Ph.D.
Department of Physics
Sciences
Physics PhD
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Lawson, Robert Chester. "A study of periodic gratings in planar dielectric waveguides." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-05022009-040647/.
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Li, Ming. "Optical waveguide chip-to-chip interconnection using grating couplers." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282202.
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Lang, Ryan N. (Ryan Nathan). "Design of a high index contrast arrayed waveguide grating." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/32314.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science; and, (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2003.S.B. and S.M. theses issued separately.
Includes bibliographical references (p. 115-119).
Arrayed waveguide gratings (AWGs) are useful structures for the implementation of wavelength division multiplexing. The AWG consists of an input splitter, a dispersive waveguide array which creates the wavelength demultiplexing and multiplexing effects, and an output coupler. Because the dispersive waveguide array consists of bent waveguides, the size of an AWG is limited by the light loss in the bends. In their current form, silica-based gratings are too large to be made cheaply or to use as an integrated component. The proposed solution is to redesign the AWG using high index contrast materials for tight confinement of the waveguide modes and, consequently, low bend loss. A rough design is presented for a high index contrast AWG using multimode interference couplers as the coupling stages. The major components were simulated using finite difference time domain (FDTD) techniques to find low loss but rather high crosstalk. A second possible design is also presented, making use of a coupled waveguide array as the input element. The coupling coefficients of as many as 41 coupled waveguides were adjusted to create a Gaussian profile as an input to the dispersive section of the AWG. The output coupler, however, will make use of more standard free space diffraction techniques, making the overall concept a unique mixture of waveguide and free space optical elements.
by Ryan N. Lang.
S.B.
M.Eng.
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Al-Awami, Moneer Hussein Baqir. "Experimental study of the interaction of laser light with liquid crystal guides and gratings." Thesis, University of Salford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253054.
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Wildermuth, Eberhard. "Performance optimization of flat-top passband arrayed waveguide grating demultiplexers /." Zürich, 2000. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=13440.
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Nadler, Christoph. "Polarization insensitive arrayed waveguide grating wavelength multiplexers for optical communication /." Zürich, 1998. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=12957.
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Kakehashi, S., H. Hasegawa, K. Sato, and O. Moriwaki. "Interleaved Waveband MUX/DEMUX Developed on Single Arrayed-Waveguide Grating." IEEE, 2008. http://hdl.handle.net/2237/12089.
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Hu, Zhixiong. "Development of an integrated microspectrometer using arrayed waveguide grating (AWG)." Thesis, University of Glasgow, 2012. http://theses.gla.ac.uk/3439/.
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With non-invasive properties and high sensitivities, portable optical biosensors are extremely desirable for point-of-care (POC) applications. Lab-on-a-chip technology such as microfluidics has been treated as an ideal approach to integrate complex sample processing and analysis units with optical detection elements. Spectroscopic sensing (such as fluorescence, Raman and absorption spectroscopy) remains the most highly developed, widely applied, optical technique. However, conventional spectroscopic sensing systems still rely on bulky and expensive dispersive components such as spectrophotometers in a well established laboratory. The work in this thesis is to develop an integrated dispersive component in combination with a microfluidic chip, providing a portable and inexpensive platform for on-chip spectroscopic sensing. In this study, an arrayed waveguide grating (AWG) design developed for telecommunication is re-engineered and utilized to realise a compact, dispersive optical component operating in the visible spectral region. The AWG devices operating in the visible region (λ_c=680 nm) are designed and fabricated with flame hydrolysis deposited (FHD) silica waveguide material. The micro-spectrometer in this proof of concept study has a small (1 cm x 1 cm) footprint and 8 output channels centred on different wavelengths. A series of fabrication issues and challenges are investigated and discussed for the specific AWG device. Subsequently, a sample cuvette is formed by using lithographic technique and dry etching process. Following this, a PDMS chip with microfluidic channels is bonded with the AWG device, leading to an integrated AWG-microfluidic platform. To the best of the author’s knowledge, this is the first work to integrate a visible AWG device and a microfluidic chip towards spectroscopic sensing. The monolithic integrated AWG microspectrometer–microfluidic platform is demonstrated for fluorescence spectroscopic analysis. Signals from the output channels detected on a camera chip can be used to re-create the complete fluorescence spectrum of an analyte. By making fluorescence measurements of (i) mixed quantum dot solutions, (ii) an organic fluorophore (Cy5) and (iii) the propidium iodide (PI)-DNA assay, the results obtained illustrate the unique advantages of the AWG platform for simultaneous, quantitative multiplex detection and its capability to detect small spectroscopic shifts. Although the current system is designed for fluorescence spectroscopic analysis, in principle, it can be implemented for other types of analysis, such as Raman spectroscopy. Fabricated using established semiconductor industry methods, this miniturised platform holds great potential to create a handheld, low cost biosensor with versatile detection capability. Also, the AWG device design is modified with focusing properties that enable localised spectroscopic measurements. Micro-beads based, multiplexed fluorescence detection is performed with the AWG + CCD system and the results have demonstrated capabilities of using the adapted AWG device for localised, multiplexed fluorescence detections, opening up potential applications in the field of cell sorting and single cell analysis. Furthermore, the AWG-microfluidic device is investigated for absorption spectroscopy measurement. As a test system, the pH dependence of the absorption spectra of bromophenol blue is measured to illustrate how an AWG device could be used as a colorimetric pH sensor. Overall, it is believed that the AWG technology holds great potential to realise a compact, integrated spectroscopic biosensor for point-of-care applications.
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Gong, Qian. "Input and output waveguide grating couplers: Theory, fabrication and testing." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185250.
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This dissertation investigates the modeling, design, fabrication and testing of the input and output coupling properties of waveguide grating couplers. It is motivated by the application of waveguide gratings to integrated optics. The coupling in both normal incidence and oblique incidence are described, but more attention is paid to the normal incident case. The perturbation transmission line theory is chosen as a theoretical model to design grating couplers in this work. The fundamental coupling parameters were carefully measured by many experiments. The comparison of experimental results to theoretical results is also discussed in this dissertation. For the case of normal incidence, the emphasis is on the optimization of the input coupling efficiency. The maximum input coupling efficiency carried out from our experiment was 75% by means of blazed grating in dielectric waveguide at a wavelength 0.6328 $\mu$m, which is very close to the maximum theoretical value of 80%. This coupling efficiency is significantly larger than that having been reported (40-50%). To achieve this goal, some parameters, such as, output coupling efficiency (branching ratio) and coupling distance (leakage factor), have been measured to test the theoretical model. The effect of the angular divergence and the wavelength dispersion of the incident beam on the input coupling efficiency is taken into account, which was modeled by coupled mode equation and tested by experiment. In addition, the design and fabrication procedure is also discussed in detail. In the case of oblique incidence the emphasis is on the output coupling only, i.e. the coupling from guided wave to radiated wave. In this part of the work the important features of the radiated wave-mode coupling efficiency and mode-conversion efficiencies, the phase difference between TE and TM components and the polarization state--were revealed and compared with the theory. These parameters were measured using one shallow rectangular grating and one deep blazed grating. These measurements were compared with the theoretical model.
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Bates, Allen Keith. "Fabrication and characterization of variable groove depth grating waveguide couplers." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186939.
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Variable groove depth grating waveguide couplers (VGDGWCs) can be used to couple light into or out of planar waveguides. In principle an out-coupled light beam with any arbitrary irradiance profile can be obtained. VGDGWCs that produce out-coupled beams exhibiting a Gaussian irradiance profile are examined in this report. An expression for the grating groove depth variation necessary to produce Gaussian beams from VGDGWCs is derived. The design of a VGDGWC using two different materials for the host planar waveguide is presented. The designs are optimized with a consideration of the waveguide materials, the fabrication process, and the out-coupled beam quality. Two methods, that utilize ion etching to fabricate VGDGWCs are presented. Each method operates by limiting the cross sectional area of an ion beam. A scanning slit is used for one method and a moving variable width aperture is employed for the second. The ion etching process for each of the fabrication methods is characterized by a series of ion beam etching experiments. The results from the ion beam etching experiments are used to optimize the fabrication process. The variable width aperture fabrication method in combination with a post etching process, is found to produce the optimum results. The measured irradiance profile and the wavefront quality of the out-coupled beams from the fabricated VGDGWCs are compared to theory. The variable width aperture fabrication method is found to produce out-coupled beams with a nearly perfect Gaussian irradiance profile. The measured wavefront quality of out-coupled beams shows good agreement with theory.
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MOSHREFZADEH, ROBERT SHAHRAM. "THEORY AND FABRICATION OF SUB-MICRON GRATINGS ON NONLINEAR OPTICAL WAVEGUIDES." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184138.
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Because of their compatibility with the planar concept of integrated optics, grating couplers offer the most satisfactory means of coupling light into thin film optical waveguides. The purpose of this dissertation has been to study the behaviour, both theoretically and experimentally, and fabrication of grating couplers in nonlinear waveguides. A theory of nonlinear grating couplers is presented based on a coupled-mode approach. The dependence of coupling efficiency on incident beam intensity, beam size, beam position, incident angle, chirp rate, and waveguide losses have been examined all in the presence of nonlinearities in the waveguide. It is reported that, in the presence of nonlinearities, the coupling efficiency decreases with increasing incident power. Different ways of optimizing the coupling efficiency at high incident power levels are presented. These include adjusting the beam size, the coupling angle, and chirping the grating. A new technique is reported for fabrication of regular period, chirped, and curved photoresist gratings. The experimental arrangement is essentially based on Lloyd's mirror fringes and is characterized by its stability, simplicity, and versatility. We also report on successful use of Reactive Ion-Beam Etching (RIBE) with C₂F₆ gas in producing very smooth and deep gratings with high aspect ratios in different waveguide structures. Experimental coupling efficiencies of up to 40% are reported in polystyrene waveguides using etched grating couplers. Experiments are reported in support of the theoretical findings of this dissertation using a polystyrene waveguide with thermal nonlinearity.
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Kultavewuti, Pisek. "Pulse Shaping Based on Integrated Waveguide Gratings." Thesis, 2012. http://hdl.handle.net/1807/32581.
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Temporal pulse shaping based on integrated Bragg gratings is investigated in this work to achieve arbitrary output waveforms. The grating structure is simulated based on the sidewall-etching geometry in an AlGaAs platform. The inverse scattering employin the Gel'fan-Levithan-Marchenko theorem and the layer peeling method provides a tool to determine grating structures from a desired spectral reflection response. Simulations of pulse shaping considered flat-top and triangular pulses as well as one-to-one and one-to-many pulse shaping. The suggested grating profiles revealed a compromise between performance and grating length. The integrated grating, a few hundred microns in length, could generate flat-top pulses with pulse durations as short as 500 fs with rise/fall times of 200 fs; the results are comparable to previous work in free-space optics and fiber optics. The theories and the devised algorithms could serve as a design station for advanced grating devices for, but not restricted to, optical pulse shaping.
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Liao, Xin-Yu, and 廖昕昱. "Vibration sensing and positioning applications of fiber Bragg gratings and arrayed waveguide gratings." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ey7v73.
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碩士國立虎尾科技大學
光電工程系光電與材料科技碩士班
105
In this study, we combine fiber Bragg grating and arrayed waveguide grating to achieve vibration sensing system. The reflection wavelength of fiber Bragg grating is sensitive to strain, temperature and vibration. When the vibration signal applied to the fiber Bragg grating, it will caused the center wavelength changed. Utilize the slope of the arrayed waveguide grating pass band to accomplish light intensity modulation. Arrayed waveguide gratings can use multiple fiber Bragg gratings for multi-point measurements. We use two fiber Bragg grating sensors to measure vibration. We apply vibration signal between two fiber Bragg gratings. The oscilloscope shows the different time of two measured signals. We can calculated distance which is vibration signal between the two fiber Bragg gratings.