Thin Fast Steering Mirror (TFSM)

The Navy is developing LADAR sensors for responsive Intelligence, Surveillance and Reconnaissance use where ranges to targets exceed 10km. If such a LADAR sensor is to image a target area by scanning one or several laser beams at such long ranges, high-pointing-accuracy or knowledge, over a wide operational temperature range, is required to obtain a high-quality LADAR image. A two-axis Fast Steering Mirror (FSM) is typically utilized to steer laser beams in a LADAR system. Existing FSM designs that can achieve high pointing accuracy and are small enough for use aboard a tactical unmanned air vehicle often require significant settling times to achieve the pointing accuracy. Also, the knowledge of the location of the FSM (angularly) is not well-known throughout the mirror motion. When used to steer a pulsed laser beam with pulse repetition frequencies on the order of kilohertz, it is necessary to have accurate knowledge of the mirror position whenever a laser pulse occurs. ATA is proposing a concept for a thin FSM which can meet stringent performance requirements over a temperature range of-40 degrees C to +75 degrees C. This requires temperature control of the sensor electronics and uses an innovative actuator concept.