Honari, Shahin2024-08-262024-08-262024https://hdl.handle.net/1828/20308This thesis investigates the fabrication and characterization of Silica on Silicon (SoS) microcavities, for potential comb generation and sensing applications. In this thesis, novel approaches were introduced on silica-on-silicon microdisks to remove some of the inherent hurdles, namely mitigating the rough surface through chemo-mechanical polishing, and suppressing buckling-induced mechanical instability by introducing a rib disk structure. Quality factors as high as 10₈ were achieved for polished disks. Furthermore using the rib-disk structure, microdisks with thickness smaller than 1.5µm and quality factors as high as 10₇ materialized. By addressing these challenges we unleash the enormous potentials of ultra-high Q silica microdisks in microcomb generation in visible regime and sensing. Finally, a multi-transverse mode dense comb generation scheme on this platform is investigated.enAvailable to the World Wide WebThesis