This dissertation reports very novel solutions for the trimming and compensation of various parameters of silicon micromechanical resonators and resonator-arrays. Post-fabrication trimming of resonance frequency to a target value is facilitated by diffusing in a deposited thin metal layer into a Joule-heated silicon resonator. Up to ~400 kHz of trimming-up and trimming-down in a 100 MHz Silicon Bulk Acoustic Resonators (SiBARs) are demonstrated via gold and aluminum diffusion respectively. The dependence of the trimming range on the duration of Joule heating and value of current passed are presented and the possibility of extending the trimming range up to ~4 MHz is demonstrated. Passive temperature compensation techniques are developed to drastically reduce the temperature coefficient of frequency (TCF) of silicon resonators. The dependence of TCF on the charge carriers in silicon are extensively studied and exploited for the very first time to achieve temperature compensation. A charge surplus via degenerate doping using boron and aluminum is shown to reduce a starting TCF of -30 ppm/°C to -1.5 ppm/°C while a charge depletion effected by creating multiple pn-junctions reduces the TCF to -3 ppm/°C. Further, shear acoustic waves in silicon microresonators have also been identified to effect a TCF reduction and have been excited in a concave SiBAR (or CBAR) to exhibit a TCF that is 15 ppm/°C lesser than that of a conventional rectangular SiBAR. The study on quality factor (Q) sensitivity to the various crystallographic axis of transduction in silicon resonators show that the non-repeatability of Q across various fabrication batches are due to the minor angular misalignment of ≤ 0.5° during the photolithography processes. Preferred axes of transduction for minimal misalignment sensitivity are identified and novel low-loss resonator-array type performances are also reported from a single resonator while transduced along certain specific crystallographic axes. Details are presented on an unprecedented new technique to create and fill charge traps on the silicon resonator which allows the operation of the capacitive SiBARs without the application of any polarization voltages (Vp) for the first time, making them very attractive candidates for ultra-low-power oscillator and sensor applications. Finally, a fabrication process that integrates both the capacitive and piezoelectric actuation/sensing schemes in microresonators is developed and is shown to compensate for the parasitics in capacitive silicon resonators while maintaining their high-Q.

Optical traveling-wave resonator architectures have shown promise for the realization of many compact photonic functionalities in different research disciplines. Realizing these resonator structures in high-index contrast silicon enables dense and large scale integration of large arrays of functionalized resonators in a CMOS-compatible technology platform. Based on these motivations, the main focus of this Ph.D. research has been on the device physics, modeling, implementations, and applications of planar ultra-high Q silicon traveling-wave microresonators in a silicon-on-insulator (SOI) platform. Microdisk, microring, and racetrack resonators are the three general traveling-wave resonator architectures of interests that I have investigated in this thesis, with greater emphasis on microdisks. I have developed efficient tools for the accurate modeling of these resonators. The coupling to these resonators has been through a nano-waveguide side coupled to them. For this purpose, I have developed a systematic method for engineering a waveguide-resonator structure for optimum coupling. I have addressed the development of nanofabrication techniques for these resonators with efficient interaction with a nano-waveguide and fully compatible with active electronic integration. The outcome of the theoretical design, fabrication, and characterization of these resonators is a world-record ultra-high Q (3×10[superscript 6]) with optimum waveguide-resonator interaction. I have investigated the scaling of these resonators toward the ultimate miniaturization and its impact on different physical properties of the resonators. As a result of these investigations, I have demonstrated miniaturized Si microdisk resonators with radii of ~ 1.5 micron and Q > 10⁵ with single-mode operation over the entire large free-spectral range. This is the highest Q (~ one order more than that in previously reported data) that has been obtained for a Si microdisk resonator with this size on a SiO₂ substrate. I have employed these resonators for more advanced functionalities such as large-scale integration of resonators for spectroscopic and filtering applications, as well as the design of flat-band coupled-resonator filter structures. By proposing a systematic method of design, I have shown ultra-compact coupled-resonator filters with bandwidths ranging from 0.4 to 1 nm. I have theoretically and experimentally investigated the performance of ultra-high Q resonators at high powers and in the presence of nonlinearities. At high powers, the presence of two-photon absorption, free-carrier generation, and thermo-optic properties of silicon results in a rich dynamic in the response of the resonator. In both theory and experiment, I have predicted and demonstrated self-sustained GHz oscillation on the amplitude of an ultra-high Q resonator pumped with a continuous-wave laser.

This dissertation addresses three research challenges in planar lightwave circuit (PLC) optical signal processing. 1. Dynamic localization, a relatively new class of quantum phenomena, has not been demonstrated in any system to date. To address this challenge, the quantum system was mapped to the optical domain using a set of curved, coupled PLC waveguides in aluminum gallium arsenide (AlGaAs). The devices demonstrated, for the first time, exact dynamic localization in any system. These experiments motivate further mappings of quantum phenomena in the optical domain, leading toward the design of novel optical signal processing devices using these quantum-analog effects. 2. The PLC microresonator promises to reduce PLC device size and increase optical signal processing functionality. Microresonators in a parallel cascaded configuration, called "side coupled integrated spaced sequence of resonators" (SCISSORs), could offer very interesting dispersion compensation abilities, if a sufficient number of rings is present to produce fully formed "Bragg" gaps. To date, a SCISSOR with only three rings has been reported in a high-index material system. In this work, one, two, four and eight-ring SCISSORs were fabricated in AlGaAs. The eight-ring SCISSOR succeeded in producing fully formed Bragg peaks, and offers a platform to study interesting linear and nonlinear phenomena such as dispersion compensators and gap solitons. 3. PLCs are ideal candidates to satisfy the projected performance requirements of future microchip interconnects. In addition to data routing, these PLCs must provide over 100-bit switchable delays operating at ~ 1 Tbit/s. To date, no low loss optical device has met these requirements. To address this challenge, an ultrafast, low loss, switchable optically controllable delay line was fabricated in AlGaAs, capable of delaying 126 bits, with a bit-period of 1.5 ps. This successful demonstrator offers a practical solution for the incorporation of optics with microelectronics systems. The three aforementioned projects all employ, in their unique way, the coupling of light between PLC waveguides in AlGaAs. This central theme is explored in this dissertation in both its two- and multi-waveguide embodiments.

This dissertation addresses three research challenges in planar lightwave circuit (PLC) optical signal processing. 1. Dynamic localization, a relatively new class of quantum phenomena, has not been demonstrated in any system to date. To address this challenge, the quantum system was mapped to the optical domain using a set of curved, coupled PLC waveguides in aluminum gallium arsenide (AlGaAs). The devices demonstrated, for the first time, exact dynamic localization in any system. These experiments motivate further mappings of quantum phenomena in the optical domain, leading toward the design of novel optical signal processing devices using these quantum-analog effects. 2. The PLC microresonator promises to reduce PLC device size and increase optical signal processing functionality. Microresonators in a parallel cascaded configuration, called "side coupled integrated spaced sequence of resonators" (SCISSORs), could offer very interesting dispersion compensation abilities, if a sufficient number of rings is present to produce fully formed "Bragg" gaps. To date, a SCISSOR with only three rings has been reported in a high-index material system. In this work, one, two, four and eight-ring SCISSORs were fabricated in AlGaAs. The eight-ring SCISSOR succeeded in producing fully formed Bragg peaks, and offers a platform to study interesting linear and nonlinear phenomena such as dispersion compensators and gap solitons. 3. PLCs are ideal candidates to satisfy the projected performance requirements of future microchip interconnects. In addition to data routing, these PLCs must provide over 100-bit switchable delays operating at ~ 1 Tbit/s. To date, no low loss optical device has met these requirements. To address this challenge, an ultrafast, low loss, switchable optically controllable delay line was fabricated in AlGaAs, capable of delaying 126 bits, with a bit-period of 1.5 ps. This successful demonstrator offers a practical solution for the incorporation of optics with microelectronics systems. The three aforementioned projects all employ, in their unique way, the coupling of light between PLC waveguides in AlGaAs. This central theme is explored in this dissertation in both its two- and multi-waveguide embodiments.

Les micro-résonateurs (MRs) sont devenus des éléments clés de la conception de capteurs optiques intégrés, car étant plus miniaturisés que l’existant, ils s’intègrent mieux dans des systèmes ''lab-on-chip'', ce qui permet aussi de réduire le volume des molécules à détecter. Les MRs sont de plus très sensibles à la variation d’indice effectif provoquée par la présence de molécules dans le milieu de détection. Dans cette thèse, nous avons utilisé deux types de matériaux différents: les polymères et le silicium poreux. Les polymères, facilement réalisables avec des méthodes de fabrication peu onéreuses, sont dans un premier temps utilisés pour valider les outils de simulation développés pour l’étude des caractéristiques des MRs pour l’application capteur basée sur la détection par évanescence. Le silicium poreux permet d'exploiter un autre mode de détection, la détection en volume. Les molécules présentes dans le milieu de détection s'infiltrent dans le matériau et réagissent de manière directe avec la lumière. En utilisant les outils de simulation développés et en adaptant le procédé de photolithographie classique utilisé pour la fabrication de MRs en polymères, des premiers MRs constitués de guides ridges à base de silicium poreux sont mis en œuvre et caractérisés. Ces travaux de thèse démontrent expérimentalement la possibilité de détecter des concentrations de glucose avec une meilleure sensibilité que l'état de l'art pouvant atteindre les 600 nm/RIU, pour les domaines utilisant la détection et l'analyse de molécules (santé-agro, défense-sécurité, environnement). / Micro-resonators have become key element for integrated optical sensor because they offer the advantage of significantly minimizing the device size, which allows an easily integration on lab-on-chip and greatly reduces the amount of molecules to be detected. Moreover, micro-resonators are extremely sensitive to the effective index variation induced by the presence of molecules in the detection medium. The thesis focuses on two different materials: polymers and porous silicon. Firstly, polymers, easily implementable with a low cost fabrication, are used to validate the simulation tools developed for the study of micro-resonators characteristics in order to perform sensing application based on the detection by evanescence. Then, porous silicon is investigated in order to operate another type of detection, the detection by volume. The molecules to be detected and present in the medium detection infiltrate into the material and interact directly with the light. Using simulation tools and by adapting the photolithographic process used for polymers micro-resonators fabrication, the first micro-resonators based on porous silicon ridge waveguides are obtained and characterized. The work contained in this thesis demonstrate experimentally the possibility of sensing concentrations of glucose with a sensitivity of 600 nm/RIU, using volume detection, which is higher than the state of the art, for domains using the sensing and analysis of molecules (health, food industries, security and environment).

Silicon photonics has been widely recognized as a key technology that enables guiding, modulating, detecting, and computing of light in silicon chips. Photonic chips can be fabricated in a similar fashion as microelectronic chips, leveraging the mature CMOS fabrication and metrology infrastructure. Extending this technology, this dissertation focuses on two different areas : silicon microresonator-based mid-infrared light sources, and efficient strain engineering of the bandgap of two-dimensional materials. First, we review the basic theory of waveguides and ring resonators, laying the groundwork for the rest of the dissertation. Second, nonlinear optics is introduced with an emphasis on third order nonlinear phenomena including four wave mixing, the basis for Kerr frequency comb generation. Third, starting with the basic theory of lasers, we present the basic principles of quantum well lasers, leading to the discussion of quantum and interband cascade lasers. Fourth, we demonstrate a simple approach to generate mid-infrared frequency comb using a passive high-Q microresonator as well as an over one million quality factor silicon microresonator at 4.5 ?m. The novel suspended inverse taper with sub-3dB coupling loss is reported. Fifth, we demonstrate a compact narrow-linewidth widely-tunable mid-infrared laser using a high-Q external on-chip cavity. Lastly, we demonstrate highly efficient modulation of transition metal dichalcogenide monolayers (TMD) monolayers as well as TMD monolayer integrated on a silicon nitride waveguide. Additionally, we present a heterogeneous integration platform based on a thin polymer, which allows bonding as well as in principle, evanescent coupling between the two substrates.

Le développement de capteurs pour la détection de molécules présentes en très faible concentration est un enjeu sociétal et économique. Il permet de répondre à des besoins de mesure d’analytes dans les secteurs de la santé, de la défense ou encore de l’environnement. Les capteurs optiques intégrés possèdent plusieurs avantages permettant de répondre à ces problématiques. Dans cette thèse, des capteurs optiques intégrés à base de deux micro-résonateurs sont développés. Ils fonctionnent dans le domaine du proche infrarouge et permettent de détecter des molécules d’intérêt présentes en très faible quantité dans un échantillon biologique. Dans un premier temps, les critères de performances comme la sensibilité ou la limite de détection de micro-résonateurs seuls sont définis et optimisés. Puis, l’intérêt de transducteurs à base de deux micro-résonateurs cascadés ou insérés dans une structure interférométrique de type Mach-Zehnder permettant d’utiliser l’effet Vernier est mis en avant. Un algorigramme permettant d’optimiser la conception des transducteurs à effet Vernier est mis en place. Son efficacité est démontrée par la fabrication d’un transducteur à effet Vernier en matériaux polymères qui possède des performances dans l’état de l’art. Ensuite, des transducteurs en matériau silicium poreux sont étudiés. Ce matériau poreux permet d’augmenter la sensibilité du capteur en facilitant le greffage des analytes dans la structure. Les guides en silicium poreux pour la réalisation de micro-résonateurs simples sont optimisés théoriquement. L’avantage de l’utilisation conjointe de guides en polymères et en silicium poreux couplés sur la même puce intégrée, qui permet à la fois de réduire les pertes de propagation optique et d’augmenter la sensibilité du transducteur, ainsi qualifié d’hybride, est détaillé dans ce manuscrit. Les performances en sensibilité et limite de détection de transducteurs à effet Vernier hybride fabriqués à l’aide de guides en silicium poreux et en polymères sont étudiées théoriquement afin de prédire les performances de ces dispositifs. Enfin la mise en œuvre et les premiers essais de fabrication de transducteurs hybrides avec des guides en polymères et en silicium poreux sont détaillés. / The development of biosensors for the detection of extremely low concentration analytes is an economic and societal challenge. It ensures the needs to detect analytes in the economic fields of healthcare, defense and environment. Integrated optical sensors have several advantages to address these challenges. In this thesis, near infrared integrated biosensors for detection of low concentration molecules in biological samples are developed. They are based on two integrated micro-resonators transducers. Firstly, performances criterions such as sensitivity and limit of detection are defined and optimized for single micro-resonator biosensors. The advantage of micro-resonator transducers based on the Vernier effect are presented. To do so, a flowchart is developed in order to optimize the design of Vernier effect integrated transducers based on cascaded micro-resonators or micro-resonators positioned in a Mach-Zehnder interferometric structure. The efficiency of the design procedure is tested by the fabrication of a polymer transducer based on the Vernier effect with state of the art performances. Then, transducers based on porous silicon material are studied. This porous material eases the penetration and the grafting of the analytes in the sensor. Porous silicon waveguides are theoretically optimized for the fabrication of single micro-resonators. The interest of the implementation of polymer and porous silicon waveguides coupled on the same integrated chip, in order to reduce optical propagation losses and to increase sensor sensitivity, is demonstrated. The performances in sensitivity and limit of detection of hybrid porous silicon and polymer waveguides Vernier effect transducers are theoretically studied in order to estimate the performances of these integrated biosensors. Eventually, the design and the first fabrication trials of hybrid porous silicon and polymer waveguides transducers are presented.

Os micro-ressonadores que suportam whispering gallery modes têm atraído a atenção da comunidade científica devido a sua grande capacidade de confinar a luz, propriedade que faz dessas estruturas plataformas ideais para o desenvolvimento de pesquisa fundamental como interação da radiação com a matéria e óptica não linear. Além disso, suas características como operação em frequências do visível e de telecomunicações, facilidade de integração e alta sensitividade os tornam extremamente flexíveis para aplicações que vão desde filtros ópticos até sensores. Neste trabalho, demonstramos a fabricação de tais micro-ressonadores via fotopolimerização por absorção de dois fótons (FA2F). Esta técnica apresenta uma série de vantagens para a confecção de micro-dispositivos, sendo elas a capacidade de resolução inferior ao limite de difração, a flexibilidade de formas e ainda, a possibilidade de incorporar compostos de interesse à matriz polimérica a fim de introduzir novas funcionalidades ao material que compõe a estrutura final. Ademais, diferentes polímeros podem ser utilizados para a fabricação das microestruturas, tornando a técnica viável para uma vasta gama de aplicações. As microestruturas poliméricas que fabricamos são micro-cilindros ocos de boa integridade estrutural com 45 μm de diâmetro externo e 100 nm de rugosidade de superfície, o que as torna potencialmente aplicáveis como micro-ressonadores para frequências de operação típicas de telecomunicações. A fim de acoplar luz nessas estruturas, em colaboração com a Universidade de Valência, na Espanha, montamos um aparato de acoplamento. Neste aparato, a luz proveniente de uma fonte de luz centrada em 1540 nm é acoplada nos micro-ressonadores via campo evanescente por meio do uso de uma fibra óptica estirada de 1.5 μm de diâmetro. A potência transmitida é guiada para um analisador de espectro óptico, onde é possível identificar os modos ressonantes, representados como picos de atenuação com free spectral range em torno de 9.8 nm. Ao término desse projeto, um aparato similar foi montado no Grupo de Fotônica do IFSC/USP, a partir do qual pudemos medir os modos ressonantes tanto de fibras ópticas estiradas quanto dos micro-cilindros poliméricos. A finesse dos micro-ressonadores poliméricos caracterizados varia de 2.51 a 4.35, sendo da mesma ordem de grandeza do valor reportado na literatura para ressonadores de alta performance fabricados por FA2F a partir da mesma formulação de resina polimérica que utilizamos. / Whispering gallery modes microresonators have been attracting increasing interest due to their ability to strongly confine light within small dielectric volumes. This property is quite useful for basic research involving light-matter interaction and nonlinear optics, but their applications go beyond that. The ease of fabrication, on-chip integration and operation at telecommunication frequencies make them suitable for a variety of practical applications, including photonic filters and sensing. In the current work, we demonstrate the fabrication of such resonators via two-photon polymerization. Using this technique, complex 3D structures with submicrometer feature size can be produced. Besides, the flexibility of geometry and the possibility of incorporating a variety of additional materials, such as organic compounds make it a powerful tool for the fabrication of microresonators. The microstructures we have fabricated are 45 μm outer diameter hollow microcylinders, with good structural integrity and sidewall roughness estimated in 100 nm, which make their application as microresonators feasible in the near infrared wavelength regime. In order to couple light within these microresonators, an experimental setup was built at University of Valencia to implement the coupling. In this setup, light from a 1540 nm-centered broadband source was coupled into the fabricated microresonators via evanescent field using a 1.5 μm waist tapered fiber. The transmitted light was then guided to an optical spectral analyzer, where it was possible to measure resonances, represented as attenuation peaks, with free spectral range of about 9.8 nm. Afterwards, a similar experimental setup was assembled in the Photonics group at IFSC/USP, where we could observe resonances of both tapered optical fibers and the polymeric microresonators fabricated by means of two-photon polymerization. The finesse of the polymeric microresonators was estimated in 4.35, being in the same order of the finesse reported in the literature for high performance microring resonators fabricated using the same polymeric resin.

The main topic of this thesis is the performance improvement of microresonators as mass-sensitive biochemical sensors in a liquid environment. Resonant microstructures fabricated on silicon substrates with CMOS-compatible micromachining techniques are mainly investigated. Two particular approaches have been chosen to improve the resolution of resonant chemical/biochemical sensors. The first approach is based on designing a microresonator with high Q-factor in air and in liquid, thus, improving its frequency resolution. The second approach is based on minimizing the frequency drift of microresonators by compensating for temperature-induced frequency variations. A disk-shape resonant microstructure vibrating in a rotational in-plane mode has been designed, fabricated and extensively characterized both in air and in water. The designed resonators have typical resonance frequencies between 300 and 1,000kHz and feature on-chip electrothermal excitation elements and a piezoresistive Wheatstone-bridge for vibration detection. By shearing the surrounding fluid instead of compressing it, damping is reduced and quality factors up to 5800 in air and 94 in water have been achieved. Short-term frequency stabilities obtained from Allan-variance measurements with 1-sec gate time are as low as 1.1 10-8 in air and 2.3 10-6 in water. The performance of the designed resonator as a biological sensor in liquid environment has been demonstrated experimentally using the specific binding of anti-beta-galactosidase antibody to beta-galactosidase enzyme covalently immobilized on the resonator surface. An analytical model of the disk resonator, represented by a simple harmonic oscillator, has been derived and compared with experimental results. The resonance frequency and the Q-factor of the disk resonator are determined from analytical expressions for the rotational spring constant, rotational moment of inertia, and energy loss by viscous damping. The developed analytical models show a good agreement with FEM simulation and experimental results and facilitate the geometrical optimization of the disk-type resonators. Finally, a new strategy to compensate for temperature-induced frequency drifts of resonant microstructures has been developed based on a controlled stiffness modulation by an electronic feedback loop. The developed method is experimentally verified by compensating for temperature-induced frequency fluctuations of a microresonator. In principle, the proposed method is applicable to all resonant microstructures featuring excitation and detection elements.

Os micro-ressonadores que suportam whispering gallery modes têm atraído a atenção da comunidade científica devido a sua grande capacidade de confinar a luz, propriedade que faz dessas estruturas plataformas ideais para o desenvolvimento de pesquisa fundamental como interação da radiação com a matéria e óptica não linear. Além disso, suas características como operação em frequências do visível e de telecomunicações, facilidade de integração e alta sensitividade os tornam extremamente flexíveis para aplicações que vão desde filtros ópticos até sensores. Neste trabalho, demonstramos a fabricação de tais micro-ressonadores via fotopolimerização por absorção de dois fótons (FA2F). Esta técnica apresenta uma série de vantagens para a confecção de micro-dispositivos, sendo elas a capacidade de resolução inferior ao limite de difração, a flexibilidade de formas e ainda, a possibilidade de incorporar compostos de interesse à matriz polimérica a fim de introduzir novas funcionalidades ao material que compõe a estrutura final. Ademais, diferentes polímeros podem ser utilizados para a fabricação das microestruturas, tornando a técnica viável para uma vasta gama de aplicações. As microestruturas poliméricas que fabricamos são micro-cilindros ocos de boa integridade estrutural com 45 μm de diâmetro externo e 100 nm de rugosidade de superfície, o que as torna potencialmente aplicáveis como micro-ressonadores para frequências de operação típicas de telecomunicações. A fim de acoplar luz nessas estruturas, em colaboração com a Universidade de Valência, na Espanha, montamos um aparato de acoplamento. Neste aparato, a luz proveniente de uma fonte de luz centrada em 1540 nm é acoplada nos micro-ressonadores via campo evanescente por meio do uso de uma fibra óptica estirada de 1.5 μm de diâmetro. A potência transmitida é guiada para um analisador de espectro óptico, onde é possível identificar os modos ressonantes, representados como picos de atenuação com free spectral range em torno de 9.8 nm. Ao término desse projeto, um aparato similar foi montado no Grupo de Fotônica do IFSC/USP, a partir do qual pudemos medir os modos ressonantes tanto de fibras ópticas estiradas quanto dos micro-cilindros poliméricos. A finesse dos micro-ressonadores poliméricos caracterizados varia de 2.51 a 4.35, sendo da mesma ordem de grandeza do valor reportado na literatura para ressonadores de alta performance fabricados por FA2F a partir da mesma formulação de resina polimérica que utilizamos. / Whispering gallery modes microresonators have been attracting increasing interest due to their ability to strongly confine light within small dielectric volumes. This property is quite useful for basic research involving light-matter interaction and nonlinear optics, but their applications go beyond that. The ease of fabrication, on-chip integration and operation at telecommunication frequencies make them suitable for a variety of practical applications, including photonic filters and sensing. In the current work, we demonstrate the fabrication of such resonators via two-photon polymerization. Using this technique, complex 3D structures with submicrometer feature size can be produced. Besides, the flexibility of geometry and the possibility of incorporating a variety of additional materials, such as organic compounds make it a powerful tool for the fabrication of microresonators. The microstructures we have fabricated are 45 μm outer diameter hollow microcylinders, with good structural integrity and sidewall roughness estimated in 100 nm, which make their application as microresonators feasible in the near infrared wavelength regime. In order to couple light within these microresonators, an experimental setup was built at University of Valencia to implement the coupling. In this setup, light from a 1540 nm-centered broadband source was coupled into the fabricated microresonators via evanescent field using a 1.5 μm waist tapered fiber. The transmitted light was then guided to an optical spectral analyzer, where it was possible to measure resonances, represented as attenuation peaks, with free spectral range of about 9.8 nm. Afterwards, a similar experimental setup was assembled in the Photonics group at IFSC/USP, where we could observe resonances of both tapered optical fibers and the polymeric microresonators fabricated by means of two-photon polymerization. The finesse of the polymeric microresonators was estimated in 4.35, being in the same order of the finesse reported in the literature for high performance microring resonators fabricated using the same polymeric resin.