A wavelength-selective add-drop switch using silicon microring resonator with a submicron-comb electrostatic actuator

Electrostatic comb-drive micro actuator with submicron comb fingers was connected to silicon microring resonator to consist a wavelength-selective add-drop switch at 1.5μm wavelength with variable coupling mechanism. A 500nm wide 260nm thick 63.4μm long silicon microring waveguide was suspended in air with low-loss suspension arms. The air gap between the microring and the input/output waveguides was adjusted by the voltage applied to the comb actuator to vary the coupling efficiency. Transmittance from the input port to a drop port was varied 32.9dB by applying the voltages from 0V to 28.2V. At 28.2V, transmittance from the input port to a through port decreased by 7.83dB from that at 0V, and 55% of the intensity was transmitted to the drop port. The full-width-half-maximum bandwidth of the dropped light was 0.5nm, corresponding to a Q-value of 3150.