Fully tunable Fabry-Pérot cavity based on MEMS Sagnac loop reflector with ultra-low static power consumption

Abstract The Fabry-Pérot interferometer, a fundamental component in optoelectronic systems, offers interesting applications such as sensors, lasers, and filters. In this work, we show a tunable Fabry-Pérot cCavity consisting of tunable Sagnac loop reflectors (SLR) and a phase shifter based on electrostatic microelectromechanical actuators. The fabrication process of the device is compatible with the standard wafer-level passive silicon photonics platform. The electrical power and energy consumption of the device are extremely low, measuring less than 675nW of static power, and the energy needed for tuning is below 20 pJ. This electrostatic actuation mechanism provides well-balanced, scalable pathways for efficient tuning methodologies. The extinction ratio of the continuously tunable SLR's reflectivity is larger than 20 dB. Full 2π phase shifting is achieved, and all component's actuation times are less than 25 μs.