Silicon microring resonator connected with submicorn comb actuator

A 500 nm wide 260 nm thick 63.4 mum long silicon microring waveguide was suspended in air by connecting to a comb actuator with the low-loss suspension arms. The airgap between the microring and the input/output waveguides was adjusted by a voltage applied to the comb actuator to vary the coupling efficiency. Transmittance from the input to the drop waveguides was varied from 0% at the gap of 750 nm to 50% maximum value (about 30 dB) at the voltages from 0 V to 28 V. Under the drop condition, the bandwidth of the drop signal was 0.5 nm, corresponding to the Q-value of 3100.