A high-linearity, low-power 10-mm MEMS fast steering mirror with enhanced shock robustness for space laser communications.

We report a high-performance electromagnetic micro-electro-mechanical-system (MEMS) fast steering mirror (FSM) designed to meet the pressing need for miniaturized laser communication terminals on small low-earth-orbit (LEO) satellites. With a 10 mm optical aperture, the device employs a gimbal structure driven by orthogonal magnetic field components to achieve biaxial decoupling and high linearity. A bipolar magnetic configuration augments the driving torque, providing sufficient design margin for the torsion axis while reducing power consumption. Additionally, T-shaped torsion beams are utilized to enhance shock robustness without compromising the scanning range. Experimental results demonstrate a mechanical tilt of ±2.3 mrad@±52 mA with a low holding power of 54 mW per axis. Nonlinearity is only 0.04%. Resonant frequencies of 598 Hz and 819 Hz are achieved, enabling a rise time of 0.38 ms and a closed-loop 2% settling time of approximately 1.0 ms. Furthermore, the structural failure of the torsion beams was observed at a shock load of 960 g. This work provides a robust, power-efficient, and high-precision beam-steering solution for optical communication terminals on small LEO satellites.