Microresonators in CMOS Compatible Substrate

Abstract

We report our recent progress in designing and developing traveling-wave microresonators on CMOS compatible substrate, with a focus on ultra-compact Si-based microring and microdisk resonators in the visible and near infrared wavelengths with ultra-high Q and small mode volume, suitable for strong light-matter interaction. The performance of these resonators is discussed, and the design and fabrication challenges and solutions to achieve efficient coupling from the bus-waveguide to the resonator is mentioned. Coupled-resonator architectures for the design of filters are analyzed and theoretical and experimental results for the flat-band filters with wide bandwidth and large free spectral range are presented. Furthermore, by using a detailed thermal model we demonstrate optimized microresonator structures on semiconductor substrates with improved thermal conductivity that can sustain a high circulating optical intensity at the resonance wavelength, which is particularly useful for nonlinear optics and optical signal processing applications. Finally, we address some of the applications and future prospects of such microresonators in CMOS-compatible substrate technology, including portable multi-purpose bio/chemical sensing systems, reconfigurable optical signal processing modules and chip-scale optical amplifiers and lasers.