Development of novel high bandwidth beam steering mirrors

Airborne HEL applications require very stable optical line of sight jitter control. Recent requirements specify a broad range of control bandwidths from 100's hertz to a few kilohertz with corresponding LOS correction of a few milli-radians to 10's of micro-radians. These requirements are beyond current FSM technologies in a single FSM device, rather, up to three separate FSM systems tailored to specific BW and LOS excursion ranges are daisy-chained. SSG Precision Optronics proposes an integrated two-stage FSM system where a high BW fine jitter control FSM is supported by a low BW coarse fast steering platform. This approach saves space and replaces multiple elements with a single surface. The design of the fine jitter control mirror presents a particular challenge to meet stringent dynamic response and WFE requirements. However, SSG has developed a preliminary solution for further study and will prototype a scaled version from castable reaction-bonded SiC for dynamic testing in Phase 1. Developing the fine jitter stage mechanism is also a challenge where SSG offers two approaches capable of 1-2kHz BW that can be improved with further analysis. The results of analysis and dynamic testing will form the design of a dual-stage FSM device prototyped in Phase 2.