Analog Silicon Photonic MEMS phase-shifter with double-step electrostatic actuation

We present the design of an analog Silicon Photonic MEMS phase shifter based on vertically moving adiabatic couplers. Using a two-step electrostatic actuation method, the phase shifter can be turned on selectively by applying an actuation voltage on a first pair of electrodes, and the phase of the optical signal can be tuned continuously by applying an actuation voltage at a second electrode pair. A mechanical movement of only 20nm at 19V actuation voltage allows for a full π phase shift. The design exhibits a compact footprint of 60um × 44um and low excess insertion loss below 0.1dB.