Publication Details

Abstract

We have demonstrated the design and fabrication of a micro-ring resonator chip with integrated rib waveguide for evanescent coupling. It is solely based on silica thermally grown on Si, and hence avoids drawbacks such as excess fluorescence or material absorption in the UV wavelength range that are related to devices solely or partially incorporating other materials. The devices presented here deliver an intrinsic Q-factor of 3.7{\texttimes}10^-6 , exceeding the Q-factors of similar devices presented by [13] by three orders of magnitude. To our knowledge this is the highest Q-factor achieved in an integrated system made solely of thermally grown silica. This advancement was made possible by a ring resonator design based on a thicker oxide layer, the introduction of stress-relieving etch trenches as well as an optimized coupling gap design to achieve operation close to the critical coupling regime. We expect that it is possible to increase the intrinsic Q-factor by at least one order of magnitude through further optimization of the design and process technology.