Mode-Matched Multi-Ring Disk Resonator Using Single Crystal (100) Silicon

In this paper, we report two types of novel mode-matched disk resonators consisting of multi rings made by single crystal (100) silicon. One of the resonators compensates the frequency mismatch using a combination of thick ring and multiple thin rings, showing the mode mismatch as small as 43 ppm. The other one uses elliptic shape connection structures, showing the mode-mismatch as small as 61 ppm. Considering the robustness of mode matching against fabrication errors, the crystal orientation error increases the frequency mismatch more significantly in the first design, and the ring width variation causes larger frequency split in the later design.