Optofluidic flow-through biosensor devices have been in development for fast bio-target detection. Utilizing the fabrication processes developed by the microelectronics industry, these biosensors can be fabricated into lab-on-a-chip devices with a degree of platform portability. This biosensor technology can be used to detect a variety of targets, and is particularly useful for the detection single molecules and nucleic acid strands. Microfabrication also offers the possibility of production at scale, and this will offer a fast detection method for a range of applications with promising economic viability. The development of this technology has advanced to now warrant a descriptive model that will aid in the design of future iterations. The biosensor consists of multiple integrated waveguides and a microfluidic channel. This platform therefore incorporates multiple fields of study: fluorescence, optical waveguiding, microfluidics, and signal counting. This dissertation presents a model theory that integrates all these factors and predicts a biosensor design's sensitivity. The model is validated by comparing simulated tests with physical tests done with fabricated devices. Additionally, the model is used to investigate and comment on designs that have not yet been allocated time and resources to fabricate. Tangentially, an improvement to the fabrication process is investigated and implemented.

Silicon photonics (SiP) has evolved into a mature platform for cost-effective low power compact integrated photonic microsystems for many applications. There is a looming capacity crunch for telecommunications infrastructure to overcome the data-hungry future, driven by streaming and the exponential increase in data traffic from consumer-driven products. To increase data capacity, researchers are now looking at the wavelength window of the thulium-doped fiber amplifier (TDFA), centered near 2 µm as an attractive new transmission window for optical communications, motivated by the demonstrations of low loss, low nonlinearity, and high bandwidth transmission. Large-scale implementation of SiP telecommunication infrastructure will require light sources (lasers) and amplifiers to generate signals and boost transmitted and/or received signals, respectively. Silicon (Si) and silicon nitride (Si3N4) have become the leading photonic integrated circuit (PIC) material platforms, due to their low-cost and wafer-scale production of high-performance circuits. Silicon does however have a number of limitations as a photonic material, including that it is not an ideal light-emitting/amplifying material. This proposed research pertains to the fabrication of on-chip silicon and silicon nitride lasers and amplifiers to be used in a newly accessible optical communications window of the TDFA band, which is a significant step towards compact PICs for the telecommunication networks. Tellurium oxide (TeO2) is an interesting host material due to its large linear and non-linear refractive indices, low material losses and large rare-earth dopant solubility showing good performance for compact low-loss waveguides and on-chip light sources and amplifiers. Chapter 1 provides an overview of silicon photonics in the context of particularly rare earth lasers and amplifiers, operating at extended wavelengths enabled by the Thulium doped fiber amplifier. Chapter 2 presents a theoretical performance of waveguides and microresonators as the efficient structure for laser and amplifiers applications designed for optimized use in Erbium and Thulium doped fiber amplifier wavelength bands. Then spectroscopic study thulium (Tm3+) has been studied as the rare earth element for Thulium doped fiber amplifier wavelength bands. Chapter 3 presents an experimental study of TeO2:Tm3+ coated Si3N4 waveguide amplifiers with internal net gains of up to 15 dB total in a 5-cm long spiral waveguide. Chapter 4 provides a study of TeO2:Tm3+ -coated Si3N4 waveguide lasers with up to 16 mW double-sided on-chip output power. Chapter 5 presents an experimental study of low loss and high-quality factor silicon microring resonators coated with TeO2 for active, passive, and nonlinear applications. Chapter 6 represents the first demonstration of an integrated rare-earth silicon laser, with high performance, including single-mode emission, a lasing threshold of 4 mW, and bidirectional on-chip output powers of around 1 mW. Further results with a different design are presented showing lasers with more than 2 mW of double-sided on-chip output power, threshold pump powers of < 1 mW and lasing at wavelengths over a range of > 100 nm. Importantly, a simple, low-cost design was used which is compatible with silicon photonics foundry processes and enables wafer scale integration of such lasers in SiP PICs using robust materials. Chapter 7 summarizes the thesis and provides paths for future work. / Dissertation / Doctor of Engineering (DEng)

No description available.

III-V semiconductors are compounds made of elements from groups III and V of the periodic table. Most of these materials exhibit a direct bandgap, which makes them suitable for light emission and detection. Furthermore, ternary and quaternary III-V semiconductors offer some freedom in adjusting their material compositions, which also allows one to modify their bandgap energies, refractive indices, and other optical properties. This quality makes such materials suitable for the monolithic integration of laser sources with passive optical devices and detectors on a single chip. For example, such integration is used in indium phosphide (InP) technology for large-scale photonic integration in optical communication networks. Commercial integrated photonic circuits' functionality can be augmented by the implementation of nonlinear optical devices, enabling all-optical signal processing, frequency conversion, and on-chip sources of quantum light. This doctoral thesis focuses on design, fabrication, and testing of passive optical components based on III-V semiconductors. We explored various fabrication approaches for III-V nonlinear photonic devices. Among the III-V semiconductor platforms used in nonlinear photonics, we focused on AlGaAs as the most studied nonlinear optical platform, and InP and its quaternary derivatives as the most commercially developed platform. The fabrication processes for III-V photonic devices usually require the deposition of silica and chromium layers, and then three etch steps to etch the chromium, silica, and, finally, the III-V layer. In the thesis, we demonstrate a process which allows one to eliminate the chromium deposition and the associated etch step, thereby reducing the process complexity. We implemented this newly developed hard-mask process for etching numerous AlGaAs and InP photonic devices. This work was not only an important contribution to the University of Ottawa's cleanroom facility. The shared recipe can be used to recreate etch recipes for silica using soft masks like ZEP520a, PMMA, etc., at other similar university and research facilities around the world. The silica mask created using this process was later used to fabricate InP/InGaAsP-based half-core-etched and nanowire waveguides, which were used to perform the first reliable measurement of the nonlinear refractive index coefficient n₂ of InGaAsP/InP waveguides. We explored improved fabrication processes for AlGaAs waveguides, photonic crystals, and ring resonators. InP-based integrated optical devices are relatively difficult to fabricate because the etch byproducts are only volatile at elevated temperatures. Using a silica mask, we developed a very smooth etching process for InP waveguides with aspect ratios greater than 1:10. Suspended waveguide structures, where the guiding layer is surrounded by the air, are of great interest as they can exhibit large refractive index contrast for superior compactness and for achieving high intensity at low optical powers. We demonstrated fabrication process flows for creating suspended air-bridge structures in a 500-nm AlGaAs slab, which can be used in mid-IR sensing applications. The processes developed as part of this project cover a wide range of AlGaAs passive photonic devices such as waveguides, photonic crystals and ring resonators. Additionally, we demonstrated plasma etching selectivity improvements for AlGaAs etching using only a soft ZEP mask and were able to achieve a selectivity of 1:2.9. All these developments can be beneficial to other researchers working on III-V photonic devices. We also completed the first theoretical study of third-harmonic generation in dispersion-engineered AlGaAs suspended photonic crystal waveguide. Most importantly, we introduced a reliable and efficient method for modelling higher-order modes in photonic crystal waveguides that is less computationally intensive and far more accurate compared to the 3D FDTD method. We also experimentally demonstrate guided modes lying above the light line in AlGaAs photonic crystal waveguides. In one of the addition projects, we experimentally demonstrate third-harmonic generation (THG) in Silicon Nitride waveguides. In summary, this thesis presents details of the design and testing of different passive nonlinear III-V semiconductor photonic devices. In addition, this thesis presents the fabrication processes which can be used to reliably and repeatably fabricate photonic devices in these materials.

Integration of complex optical functionalities with high performance will lead to a huge development in the field of nanophotonics for a broad range of applications. Silicon photonics is currently the leading technology for the implementation of low-cost photonic integrated devices. The great potential of this technology relies on its compatibility with the mature silicon integrated circuits manufacturing based on complementary metal-oxide semiconductor (CMOS) processes widely used in microelectronic industry and the availability of high quality silicon-on-insulator wafers, an ideal platform for creating planar waveguide circuits that offers strong optical confinement due to the high index contrast between silicon (n=3.45) and silicon dioxide (n=1.45). In order to keep improving the performance of photonic devices on silicon, the integration of CMOS compatible materials with unique properties shows up as an excellent opportunity to overcome the current limitations in silicon while offering unprecedented and novel capabilities to the silicon platform. In this way, barium titantate (BaTiO3) stands out as one of the most disruptive candidates. The work developed in this thesis is essentially focused on the design, fabrication and characterization of an electro-optic modulator based on a hybrid BaTiO3 on silicon structure for the implementation of high performance electro-optic functionalities with beyond state-of-the art performance that currently cannot be afforded in silicon photonics technology. / La integración de funcionalidades ópticas con alto rendimiento llevará a un gran desarrollo en el campo de la nanofotónica para un amplio abanico de aplicaciones. Actualmente, la fotónica de silicio es la tecnología líder para la implementación de dispositivos fotónicos integrados a bajo coste. El gran potencial de esta tecnología reside en su compatibilidad con las maduras técnicas de fabricación de circuitos integrados de silicio basadas en los procesos "complementary metal-oxide semiconductor" (CMOS) ampliamente utilizados en la industria microelectrónica y la disponibilidad de disponer de obleas de silicio sobre aislante de alta calidad, una plataforma ideal para crear circuitos de guía de ondas planas que ofrecen un fuerte confinamiento óptico debido al alto contraste índices entre el silicio (n=3,45) y el dióxido de silicio (n=1,45). Para poder mejorar el rendimiento de dispositivos fotónicos en silicio, la integración de materiales con propiedades excepcionales y compatibles con los procesos de fabricación CMOS surge como una excelente oportunidad para superar las actuales limitaciones de la tecnología de silicio al mismo tiempo que ofrece oportunidades novedosas y sin precedentes en la plataforma de silicio. En este sentido, el material titanato de bario (BaTiO3) se postula como uno de los candidatos más prometedores. El trabajo desarrollado en esta tesis está esencialmente enfocado en el diseño, fabricación y caracterización de un modulador electro-óptico basado en una estructura híbrida de BaTiO3 en silicio para la implementación de funcionalidades electro-ópticas de alto rendimiento más allá del estado del arte de las que no se puede disponer actualmente en la tecnología de fotónica de silicio. / La integració de funcionalitats òptiques amb alt rendiment portarà a un gran desenvolupament en el camp de la nanofotònica per a un ampli ventall d'aplicacions. Actualment, la fotònica de silici és la tecnologia capdavantera per a la implementació de dispositius fotònics integrats a baix cost. El gran potencial d'aquesta tecnologia resideix en la seva compatibilitat amb les madures tècniques de fabricació de circuits integrats de silici basades en els processos "complementary metal-oxide semiconductor" (CMOS) amplament utilitzats en la indústria microelectrònica i la disponibilitat de disposar d'hòsties de silici sobre aïllant d'alta qualitat, una plataforma ideal per crear circuits de guia d'ones planes que ofereixen un fort confinament òptic a causa de l'alt contrast d'índexs entre el silici (n=3,45) i el diòxid de silici (n=1,45). Per poder millorar el rendiment de dispositius fotònics en silici, la integració de materials amb propietats excepcionals i compatibles amb els processos de fabricació CMOS sorgeix com una excel·lent oportunitat per superar les actuals limitacions de la tecnologia de silici al mateix temps que ofereix oportunitats noves i sense precedents en la plataforma de silici. En aquest sentit, el material titanat de bari (BaTiO3) es postula com un dels candidats més prometedors. El treball desenvolupat en aquesta tesi està essencialment enfocat en el disseny, fabricació i caracterització d'un modulador electro-òptic basat en una estructura híbrida de BaTiO3 en silici per a la implementació de funcionalitats electro-òptiques d'alt rendiment més enllà de l'estat de l'art de les quals no es pot disposar actualment a la tecnologia de fotònica de silici. / Castera Molada, P. (2017). Development of new photonic devices based on barium titanate in silicon [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86197

The objective of this research is to investigate the use of laser direct writing to micro-pattern low loss passive optical channel waveguide devices using a new hybrid organic/inorganic polymer. Review of literature shows previous methods of optical waveguide device patterning as well as application of other non-polymer materials. System setup and design of the waveguide components are discussed. Results show that laser direct writing of the hybrid polymer produce single mode interconnects with a loss of less 1dB/cm.

Photonics has consistently played an important role in the investigation of quantum-enhanced technologies and the corresponding study of fundamental quantum phenomena. The majority of these experiments have relied on the free space propagation of light between bulk optical components. This relatively simple and flexible approach often provides the fastest route to small proof-of-principle demonstrations. Unfortunately, such experiments occupy significant space, are not inherently phase stable, and can exhibit significant scattering loss which severely limits their use. Integrated photonics offers a scalable route to building larger quantum states of light by surmounting these barriers. In the first half of this thesis, we describe the operation of on-chip heralded sources of single photons. Loss plays a critical role in determining whether many quantum technologies have any hope of outperforming their classical analogues. Minimizing loss leads us to choose Spontaneous Four-Wave Mixing (SFWM) in a silica waveguide for our source design; silica exhibits extremely low scattering loss and emission can be efficiently coupled to the silica chips and fibers that are widely used in quantum optics experiments. We show there is a straightforward route to maximizing heralded photon purity by minimizing the spectral correlations between emitted photon pairs. Fabrication of identical sources on a large scale is demonstrated by a series of high-visibility interference experiments. This architecture offers a promising route to the construction of nonclassical states of higher photon number by operating many on-chip SFWM sources in parallel. In the second half, we detail one of the first proof-of-principle demonstrations of a new intermediate model of quantum computation called boson sampling. While likely less powerful than a universal quantum computer, boson sampling machines appear significantly easier to build and may allow the first convincing demonstration of a quantum-enhanced computation in the not-distant future. Boson sampling requires a large interferometric network which are challenging to build with bulk optics, we therefore perform our experiment on-chip. We model the effect of loss on our postselected experiment and implement a circuit characterization technique that accounts for this loss. Experimental imperfections, including higher-order emission from our photon pair sources and photon distinguishability, are modeled and found to explain the sampling error observed in our experiment.

Résumé : Malgré le nombre croissant de capteurs dans les domaines de la chimie et la biologie, il reste encore à étudier en profondeur la complexité des interactions entre les différentes molécules présentes lors d’une détection à l’interface solide-liquide. Dans ce cadre, il est de tout intérêt de croiser différentes méthodes de détection afin d’obtenir des informations complémentaires. Le principal objectif de cette étude est de dimensionner, fabriquer et caractériser un détecteur optique intégré sur verre basé sur la résonance plasmonique de surface, destiné à terme à être combiné avec d’autres techniques de détection, dont un microcalorimètre. La résonance plasmonique de surface est une technique reconnue pour sa sensibilité adaptée à la détection de surface, qui a l’avantage d’être sans marquage et permet de fournir un suivi en temps réel de la cinétique d’une réaction. L’avantage principal de ce capteur est qu’il a été dimensionné pour une large gamme d’indice de réfraction de l’analyte, allant de 1,33 à 1,48. Ces valeurs correspondent à la plupart des entités biologiques associées à leurs couches d’accroche dont les matrices de polymères, présentés dans ce travail. Étant donné que beaucoup d’études biologiques nécessitent la comparaison de la mesure à une référence ou à une autre mesure, le second objectif du projet est d’étudier le potentiel du système SPR intégré sur verre pour la détection multi-analyte. Les trois premiers chapitres se concentrent sur l’objectif principal du projet. Le dimensionnement du dispositif est ainsi présenté, basé sur deux modélisations différentes, associées à plusieurs outils de calcul analytique et numérique. La première modélisation, basée sur l’approximation des interactions faibles, permet d’obtenir la plupart des informations nécessaires au dimensionnement du dispositif. La seconde modélisation, sans approximation, permet de valider le premier modèle approché et de compléter et affiner le dimensionnement. Le procédé de fabrication de la puce optique sur verre est ensuite décrit, ainsi que les instruments et protocoles de caractérisation. Un dispositif est obtenu présentant des sensibilités volumiques entre 1000 nm/RIU et 6000 nm/RIU suivant l’indice de réfraction de l’analyte. L’intégration 3D du guide grâce à son enterrage sélectif dans le verre confère au dispositif une grande compacité, le rendant adapté à la cointégration avec un microcalorimètre en particulier. Le dernier chapitre de la thèse présente l’étude de plusieurs techniques de multiplexage spectral adaptées à un système SPR intégré, exploitant en particulier la technologie sur verre. L’objectif est de fournir au moins deux détections simultanées. Dans ce cadre, plusieurs solutions sont proposées et les dispositifs associés sont dimensionnés, fabriqués et testés. / Abstract : In spite of the growing number of available biosensors, many biochemical reactions and biological components have not yet been studied in detail. Among them, some require the combination of several detection techniques in order to retrieve enough information to characterize them fully. An unknown reaction based, for example, on DNA hybridization could be characterized with an electrochemical sensor, a mechanical sensor and an optical sensor, each giving a different type of information. The main objective of the work presented here is to design, fabricate and characterize a flexible integrated optical biosensor based on surface plasmon resonance, intended to be then combined with other detection techniques, and in particular, a microcalorimeter. Surface Plasmon Resonance (SPR) is well known to be a sensitive technique for surface-based biochemical detection. It has the advantage to be an unlabeled method and provides real time information on the kinetics of a reaction. The flexibility of the proposed SPR biosensor comes from the fact that it is designed for a large range of analyte refractive indices, from 1.33 to 1.48. These values are suitable for most biological entities and their ligand layers, and especially for hydrophilic polymer matrices used to trap DNA or protein entities and introduced in this work. As several biochemical studies require the simultaneous comparison of measurements to a reference or to another measurement, the second objective of this project is to study the potential of multi-analyte detection in an integrated SPR device on glass. The first three chapters of the thesis are focused on the main objective. The design based on two different models is presented, at the same time as the related simulation tools. The first model is based on the weak coupling approximation and permits to obtain most of the information for the device’s design. The second model, having no approximation, is used to validate the first model and complete and refine the design. The fabrication process of the glass chip is then introduced, as well as the characterization instruments and protocols. A device is obtained, with a volumetric sensitivity between 1000 nm/RIU and 6000 nm/RIU depending on the analyte refractive index. The 3D integration of the waveguide within the glass substrate makes the device extremely compact and adapted to the integration with the microcalorimeter in particular. The last chapter describes the study of several spectral multiplexing techniques adapted to an integrated SPR system using the glass technology. The goal is to provide at least two simultaneous measurements. Several detection techniques are examined and the related devices are designed, fabricated and characterized.

Les guides à cristaux photoniques sont des guides optiques structurés à des échelles inférieures à la longueur d’onde. La vitesse de groupe de l’onde guidée y est ralentie. L’intensité du champ électromagnétique est ainsi exaltée et permet d’envisager de nombreuses applications pour le traitement optique de l'information. Cependant cette exaltation rend aussi les guides particulièrement sensibles aux imperfections de fabrication. Nous réalisons ici une étude théorique, numérique et expérimentale du transport de la lumière lente dans ces guides en présence de désordre. Le travail théorique propose une extension des méthodes perturbatives (de type Born) au cas des modes de Bloch électromagnétiques et un outil numérique original pour prendre en compte la diffusion multiple, qui devient déterminante lorsque la vitesse diminue. Les prédictions de ces deux types d'analyse ont été confrontées à des résultats expérimentaux. Pour la première fois dans les guides à cristaux photoniques, nous avons mesuré les statistiques d'ensemble du transport, en recoupant des mesures réalisées sur 18 échantillons identiques au désordre de fabrication près. Nous mettons en évidence les véritables limites de fonctionnement de ces guides. Ils ne sont limités ni par la dispersion, ni par leur atténuation moyenne. Les phénomènes de diffusion multiple modifient par contre considérablement la loi de probabilité de transmission. Pour pouvoir utiliser les guides à cristaux photoniques, il faut donc rester dans des régimes de fonctionnement où la diffusion multiple est négligeable, c’est-à-dire soit pour des vitesses de groupe relativement grandes (vg > c/20), soit pour des longueurs de guide faibles. / Photonic crystals are optical materials in which patterning of dielectric materials on a sub-wavelength scale creates unusual optical properties such as propagation speeds that are much slower than the speed of light. Electromagnetic fields are locally enhanced and light-matter interactions are thereby increased. However, because of this enhancement, the waveguides are much more sensitive to fabrication disorder. In this manuscript, we develop a theoretical, numerical and experimental analysis of the light transport in disordered waveguides. The theoretical work proposes an extension of the Born approximation to the case of electromagnetic Bloch modes and a new numerical tool which considers the multiple-scattering that becomes dominant when the group velocity decreases. Predictions of both models have been compared to experimental results. For the first time in photonic crystal waveguides, we measured ensemble-averaged quantities of photonic transport, collected on a series of 18 waveguides that are nominally identical and that only differ by statistical structural imperfections. We deduced the actual working limitations of these guides: they are limited neither by their GVD nor by their averaged losses. However multiple-scattering processes change the transmission probability density function dramatically. In order to use photonic crystal waveguides, it is therefore necessary to keep within regimes, where multiple scattering can be neglected, i.e. for relatively high group velocities (vg > c/20), or for short waveguide lengths.

O trabalho de doutorado teve como objetivo desenvolver um modulador óptico baseado em filme magnetostrictivo para aplicação como magnetômetro. A modelagem e simulação do dispositivo foi realizada utilizando software com cálculo por método dos elementos finitos (MEF) e teve como finalidade auxiliar iterativamente os processos de projeto e fabricação do modulador. A originalidade da proposta baseia-se na construção de um guia de onda em óptica integrada recoberto por um filme magnetostrictivo para permitir a modulação , via efeito elasto-óptico, da onda guiada pela aplicação de campos magnéticos externos. O campo magnético aplicado provoca a deformação o material magnetostrictivo que induz uma modificação no perfil de esforço aplicado ao substrato. O substrato tem suas propriedades ópticas alteradas devido ao efeito elasto-óptico, o que provoca mudanças nas propriedades da luz transmitida. O trabalho tem seu início com o estudo e a caracterização de filmes magnetostrictivos de Tb25F275 e Tb23Co77 depositados por sputtering sobre substratos de silício. Uma técnica para preparação das amostras e medição da magnetostricção foi estabelecida e os coeficientes de magnetostrição dos filmes foram determinados a partir das medições diretas dos deslocamentos das amostras, em função dos campos magnéticos aplicados, utilizando a técnica de Atomic Force Microscopy (AFM). Os resultados experimentais obtidos permitiram a realização de simulações por MEF para verificação dos modos de guiamento da luz gerados pelo perfil de esforços induzidos termicamente no processo de deposição do filme magnetostrictivo sobre substrato de B12GeO4 (BGO). Foi modelado e simulado também o efeito da aplicação do campo magnético sobre o guia óptico obtido inicialmente pelo efeito de esforço térmico. No resultado das simulações foi possível verificar as alterações do índice de refração efetivo e da intensidade óptica do modo guiado em função de campos magnéticos aplicados ao modulador. Ao final do trabalho realizaram-se a fabricação de alguns protótipos. Os resultados das caracterizações dos moduladores construídos permitirão, no futuro, ajustar os modelos de simulação elaborados. / The doctoral work aims are the development and simulation of an optical modulator based on the effect of magnetostriction for application as magnetometer. The multiphysics simulations were performed using the Finite Elements Method (FEM). In the manufacturing process of optical modulator integrated optics techniques were applied. The originality of the proposal is based on the construction of an integrated optical waveguide covered by a magnetostrictive film to allow the modulation of the guided wave, through the elasto-optical effect, by the application of external magnetic fields. The applied magnetic field causes deformation of the magnetostrictive material that induces a modification of the stress profile produced in substrate. The substrate has its optical properties altered due to the elasto-optical effect, which causes changes in the properties of transmitted light. The work begins with the study and characterization of TbFe and TbCo2 magnetostrictive films deposited by sputtering on silicon substrates. A method for sample preparation and measurement of magnetostriction was established. The magnetostrictive coefficient of the films was determined from the direct measurement of displacements of samples by AFM technique for magnetic fields applied. The experimental results obtained allowed to perform MEF simulations to verify the light guided modes generated by the profile of thermally induced stress created by deposition process of magnetostrictive film on B12GeO4 (BGO) substrate. It was also modeled and simulated the effect of the application of magnetic field on the optical guide obtained initially by the effect of thermal stress. In simulation results, it was possible to verify the changes of effective refractive index and optical intensity of guided modes as functions of magnetic fields applied to the modulator. At the end of the work, some prototypes were fabricated. The results of characterizations of the built modulators will allow, in the future, adjustments in simulation models.