Ring-resonator reflector with a waveguide crossing

We demonstrate the design and performance of a silicon-on-insulator ring-resonator reflector with a low-loss, low-crosstalk waveguide crossing. The device is simulated using the transfer-matrix method and a 2D finite-difference mode solver. It functions as a reflective-type notch filter and can be used for optical communications or thermal, biochemical, or other sensors. An extinction ratio of over 25 dB is observed experimentally.