The American Institute for Manufacturing Integrated Photonics (AIM Photonics) is focused on developing an end- to- end integrated photonics ecosystem in the U.S., including domestic foundry access, integrated design tools, automated packaging, assembly and test, and workforce development. This paper describes how the institute has been structured to achieve these goals, with an emphasis on advancing the integrated photonics ecosystem. Additionally, it briefly highlights several of the technological development targets that have been identified to provide enabling advances in the manufacture and application of integrated photonics.

The main objectives of this thesis are to develop viable process and/or device technologies for bandgap tuning of 1300-nm InGaAs/GaAs quantum-dot (QD) laser structures, and broad linewidth 1300-nm InGaAsP/InP quantum well (QW) superluminescent diode structures. The high performance bandgap-engineered QD laser structures were achieved by employing quantum-dot intermixing (QDI) based on impurity free vacancy diffusion (IFVD) technique for eventual seamless active-passive integration, and bandgap-tuned lasers. QDI using various dielectric-capping materials, such as HfO2, SrTiO3, TiO2, Al2O3 and ZnO, etc, were experimented in which the resultant emission wavelength can be blueshifted to ∼ 1100 nm ─ 1200 nm range depending on process conditions. The significant results extracted from the PL characterization were used to perform an extensive laser characterization. The InAs/GaAs quantum-dot lasers with QDs transition energies were blueshifted by ~185 nm, and lasing around ~1070 – 1190 nm was achieved. Furthermore, from the spectral analysis, a simultaneous five-state lasing in the InAs/InGaAs intermixed QD laser was experimentally demonstrated for the first time in the very important wavelength range from 1030 to 1125 nm. The QDI methodology enabled the facile formation of a plethora of devices with various emission wavelengths suitable for a wide range of applications in the infrared. In addition, the wavelength range achieved is also applicable for coherent light generation in the green – yellow – orange visible wavelength band via frequency doubling, which is a cost-effective way of producing compact devices for pico-projectors, semiconductor laser based solid state lighting, etc. [1, 2] In QW-based superluminescent diode, the problem statement lies on achieving a flat-top and ultra-wide emission bandwidth. The approach was to design an inhomogeneous active region with a comparable simultaneous emission from different transition states in the QW stacks, in conjunction with anti-reflection coating and tilted ridge-waveguide device configuration. In this regard, we achieved 125 nm linewidth from InGaAsP/InP multiple quantum well (MQW) superluminescent diode with a total output power in excess of 70 mW with an average power spectral density of 0.56 mW/nm, and a spectral ripple of ≤1.2 ± 0.5 dB. The high power and broadband SLD with flat-top emission spectrum is a desirable as optical source for noninvasive biomedical imaging techniques employing low coherence interferometry, for instance, optical coherence tomography (OCT).

Ces travaux de thèse portent sur la conception, la réalisation et d'une nouvelle génération de MOEMS (Micro-Optical-Electrical-Mechanical System) pour le contrôle actif du faisceau laser émis par des matrices de VCSELs (Vertical-Cavity Surface-Emitting Lasers). Le microsystème à base de polymères que nous avons conçu est compatible avec une intégration monolithique en post-processing. Il est composé d'une membrane suspendue associée à une microlentille réfractive. Le plan de focalisation est contrôlé dynamiquement grâce au déplacement vertical de la membrane grâce à un actionnement électrothermique. La géométrie du MOEMS a été optimisée à l'aide notamment de simulations électro-thermo-mécaniques pour minimiser l'énergie de commande et fiabiliser les dispositifs. Nous avons ensuite développé l'ensemble des briques technologiques pour la fabrication collective de ce dispositif sur des matrices de VCSELs. En particulier, une technique originale de transfert thermique doux de films secs photosensibles épais a été mise au point au moyen d'un équipement de nano-impression, pour permettre un dépôt uniforme et précis sur des substrats fragiles ou de faible taille. En outre, nous avons développé un procédé simple et totalement planaire pour la fabrication du MOEMS et optimisé un procédé de dépôt par jets d'encre pour l'intégration finale des microlentilles, avec la possibilité de choisir la distance focale la plus adaptée à la fin du process. La caractérisation des microsystèmes que nous avons réalisés a conduit à l'obtention de déplacements mécaniques de 8µm pour seulement 12.5mW appliqués, ce qui constitue une validation de nos résultats de modélisation. Enfin, des premiers résultats de focalisation dynamique du faisceau VCSELs sont présentés. / This thesis deals with the study and the fabrication of a novel type of polymer MOEMS (Micro Optical Electrical Mechanical Systems) to achieve passive or active beam shaping of Vertical-Cavity Surface-Emitting Lasers (VCSELs). To improve the photonic integration of these compact laser sources in optical communication and detection systems (sensors, biomedical analysis), we designed a polymer-based optical microsystem that is suitable with a post-processing integration on VCSELs. Its operation principle is based on the out-of-plane displacement of a suspended SU-8 membrane including a polymer refractive microlens at its surface. Thanks to electro-thermal actuation, the vertical displacement of the membrane allows to dynamically modify the microlens-source distance and leads to a vertical shift of the laser beam waist position. MOEMS actuation power and reliability were optimized owing to a comprehensive tri-dimensional thermo-electro-mechanical model that takes into account SU-8 material properties and precise geometry of the device. Technological steps necessary for the collective fabrication of such MOEMS on VCSELs arrays were also developed. In particular, we report on a new photoresist film transfer method we developed to achieve a highly uniform fabrication of high aspect ratio MOEMS on small-sized or fragile samples such as GaAs-based VCSELs wafers. This method that we call "soft thermal printing" is based on the use of a thermal nano-imprint set-up. Moreover, a simple and planar process for MOEMS fabrication was successfully tested. A dedicated inkjet printing process for drop-on-demand deposition of the microlens on the membrane center was also developed. Finally, the fabricated MOEMS were characterized. A vertical displacement as high as 8µm was observed for only 12.5mW applied, in good agreement with our 3D modeling results and first results on 850nm VCSEL dynamic beam focusing were obtained, demonstrating the interest of our approach.