Adaptive control of a MEMS steering mirror for suppression of laser beam jitter

This paper presents an adaptive control scheme for laser-beam steering by a two-axis MEMS tilt mirror. Disturbances in the laser beam are rejected by a μ-synthesis feedback controller augmented by the adaptive control loop, which determines control gains that are optimal for the current disturbance acting on the laser beam. The adaptive loop is based on an adaptive lattice filter that implicitly identifies the disturbance statistics from real-time sensor data. Experimental results are presented to demonstrate that the adaptive controller significantly extends the disturbance-rejection bandwidth achieved by the feedback controller alone.