Programmable photonic arrays based on microelectromechanical elements with femtowatt-level standby power consumption

Programmable photonic integrated circuits offer exciting opportunities for optoelectronic signal processing, computing and communications in a number of emerging applications in classical and quantum photonics. In this work, we show the array-level demonstration of tunable couplers and phase shifters with capacitive electrostatic microelectromechanical actuators in a recirculating mesh network. The overall fabrication process is compatible with the conventional wafer-level passive silicon photonics platform. Extremely low unit-level standby power consumption of <10 femtowatts and reconfiguration energy of <40 picojoules with <11 V programming voltages offer well-balanced, scalable routes for efficient phase and amplitude modulation of the guided lightwaves with sub-decibel optical losses. The extinction ratios of the continuously tunable directional coupler exceed 30 dB. Full 2 pi-phase shifting can be achieved with a modulation efficiency of less than 0.075 V cm and a phase-dependent insertion-loss variation of 0.01 dB.