Compact devices based on photonics integration

Abstract

The integration of Complementary Metal-Oxide-Semiconductor (CMOS) technology with Photonic Integrated Circuits (PICs) enables the consolidation of multiple components onto a single optical chip, supporting cost-effective applications with greater bandwidth, reduced signal loss, and lower energy consumption. This thesis focuses on the development of compact photonic devices using Silicon (Si) and Silicon Carbide (SiC) for modulators, sensors, and nonlinear photonics. Silicon Photonics, driven by the high-index-contrast waveguides of Silicon-on-Insulator (SOI) and its CMOS-compatible fabrication, has enabled efficient signal routing via compact broadband couplers and advancements in thin-film characterization and on-chip sensing using microring resonators (MRRs). SiC, particularly Cubic SiC (3C-SiC), offers scalability through epitaxial growth on silicon and supports nonlinear photonic applications with its second- and third-order nonlinearities (χ^(2) and χ^(3)). This work demonstrates χ^(3) characterization and optical parametric oscillation in 3C-SiC on Insulator (3C-SiCOI) using MRRs, facilitated by low-loss waveguides enabled by wafer bonding. The thesis further explores photothermal and χ^(2) effects in 3C-SiCOI MRRs, analyzing intrinsic losses and advancing electro-optic (EO) modulators by characterizing 3C-SiC’s EO coefficients. Lastly, second harmonic generation in 3C-SiC waveguides is optimized for visible-wavelength applications, achieving high conversion efficiency in compact designs, showcasing the potential of these platforms for integrated photonics.