Technologies for Fine Steering Mirror Systems in Free Space Optical Communication Systems

Future Free-Space Optical Communication / Lasercomm architectures have identified beam steering devices as critical path technology. Conventional Fine Steering Mirror mechanisms are a lower risk, near term solution. Typical performance requirementsinclude: up to an 8 cm aperture, ,b1,a FOR, <1 microradian pointing repeatability and 5kHz BW. SSG proposes the incremental development of three key technologies to achieve these requirements. These efforts include refinements to SSG¿¿s proprietaryOptical Position Sensor and central flexure concepts as well as improvements to the design of its voice coil motors. SSG feels that these key technologies are the ideal, low risk solution to achieving these FSM performance goals in the near future. Intheir present level of development, SSG is able to produce a FSM with 3.7 cm aperture capable of ,b0.57,a FOR, <1 microradian pointing repeatability and 2kHz BW. SSG also anticipates that wave front error correction will be a necessary function of FSMs infuture Lasercomm systems. To this end, SSG is developing a Deformable Fast Steering Mirror as part of the Tera Hertz Operational Reachback (THOR) program. The work described in this proposal complements SSG¿¿s DFSM effort as well as the anticipatedarchitectures of future Lasercomm programs such as THOR Advances in Fine Steering Mirror (FSM) technologies is necessary for future airborne and space Lasercomm architectures to accomplish their mission. There is a potential for commercial spaceLasercomm networks to evolve from a hundred optical nodes to thousands of optical nodes and terminals where each subsystem employs one or multiple FSM units. Other airborne and space based beam steering applications include fine tracking mechanisms inremote sensing and targeting systems as well as high energy laser delivery systems for NASA and DoD. However, as the technology matures and becomes less costly, these capabilities will also improve the performance of commercial ground based free-spaceoptical communication systems. As an added opportunity to these commercial potentials, SSG anticipates that wave-front correction will be an added requirement for these applications and is developing a combined Deformable Mirror and Fast Steering Mirror(DFSM).