Integrated waveguide Fabry-Perot microcavities with silicon/air Bragg mirrors

We demonstrate in-plane microfabricated Fabry-Perot cavities with cryogenically etched silicon/air distributed Bragg reflector (DBR) mirrors and integrated silicon-on-insulator rib waveguides. Several DBR configurations and cavity lengths were measured. Various devices exhibit Q =26963, FWHM 0.060 nm, finesse F= 489, free spectral range FSR = 81.7 nm, and DBR mirror reflectance R = 99.4%. Thermo-optic tuning over 6.7 nm is also demonstrated. (c) 2007 Optical Society of America.