A High-Bandwidth, High-Precision, Two-Axis Steering Mirror with Moving Iron Actuator

This paper focuses on the design, fabrication, assembly, and testing of a high bandwidth two-axis mirror positioner for precision optical platforms, which we refer to as the Advanced Fast Steering Mirror (AFSM). This novel positioner consists of a platform driven in two rotational axes by flux-steering electromagnetic actuators, and controlled via position feedback loops. The AFSM is designed for beam stabilization tasks in lithography, laser communication, lidar, and similar optical applications. We have experimentally demonstrated small-signal system bandwidth of 10 kHz using optical quad-cell feedback and a two-channel analog control architecture. The AFSM has a travel range of ±3.5 mrad, and a measured angular acceleration of 105 rad/sec2.