Component Design for InGaAsP-on-Insulator Integrated Photonics

Abstract

The growing demand for high-bandwidth data transmission, expanding communication networks, and capable sensing technologies is driven by the increasing number of internet-connected devices and the scaling of data-intensive tasks, such as artificial intelligence and high-performance computing. This has highlighted the need for technologies capable of efficient and high-speed optical signal processing. To address this need, photonic integration offers advantages over electronic technologies by more efficient power consumption, higher data bandwidth, and compact form factors for data and communication systems. Among photonic integration platforms, group III-V semiconductors offer unique advantages by integrating light generation, optical modulation, detection, and low-loss signal routing on a single material platform. In this thesis, work carried out in collaboration with Optiwave Systems Inc. and the National Research Council of Canada (NRC) is presented. This work focuses on the development of a novel material platform, based on a III-V semiconductor, Indium Gallium Arsenide Phosphide (InGaAsP)-on-insulator, chosen for its multi-functionality as a telecommunication range light source, fast electro-optic modulation, and photo-detection, not seen in other platforms such as silicon or lithium niobate. Here, integrated components developed for the telecommunication O and C bands are incorporated into a library, which can later be used in a process design kit. The component library presented includes embedded oxide strip waveguides, 90◦ circular waveguide bends, linear waveguide tapers, waveguide splitters for near-ideal 50/50 power splitting, and compact waveguide X-crossings. In addition, a subwavelength grating waveguide and broadband subwavelength grating edge coupler for efficient fibre-to-chip coupling are presented. Finally, second-harmonic generation waveguides are designed and analytically evaluated for the conversion of infrared wavelengths of 3.1 μm and 2.62 μm to telecommunication wavelengths of 1.55 μm and 1.31 μm, respectively. This work provides an essential toolkit for creating application-specific photonic integrated circuits not previously seen for the InGaAsP platform, as well as a streamlined design-to-fabrication pathway compatible with Canadian fabrication infrastructure such as the Canadian Photonics Fabrication Centre (CPFC). The results presented in this thesis will support the development of scalable photonic devices for optical communications, all-optical signal processing, and sensing applications, contributing toward Canada’s semiconductor and photonics ecosystem.