Thermally Stable, High Damping SiC Weave Optical Bench and Structure for TRP DUAL System

The extension of the proposed DUAL LIDAR system from laboratory to aircraft environment will be critically dependent on the performance of the optical bench/structure. This optical bench must support all components (telescope, scanner, lasers, resonator, beam steering optics, and detector) while maintaining critical alignment of the single-mode, heterodyned laser system. Specifically, the structure must maintain sub-0.1 milliradian level tolerances in the presence of thermal loads, gradients and drift, aircraft vibration, and varying gravitational loads; all while meeting strict weight requirements. SSG's success developing light weight, inherently athermal optical systems from bulk SiC forms the basis for the proposed innovation: creation of the DUAL LIDAR optical bench from a new fibrous weave SiC form (a continuous fiber reinforced composite). This weave SiC retains the advantages of the bulk material: low CTE, high thermal conductivity, and excellent thermal stability (>12X aluminum); while adding high damping (>10X aluminum), ultra-light weight (density = 60% of aluminum, modulus >2X aluminum), and excellent fracture toughness (can be dropped on a cement floor). Furthermore, the weave offers near-net shape fabrication for significant cost saving potential. In Phase I, SSG proposes to analyze, design, fabricate, and test a prototype optical bench/structure for the DUAL LIDAR system. This innovation will enable the airborne DUAL LIDAR system to satisfy rigid, ultra-light weight, thermally stable and durable airborne and UAV applications. Anticipated Military Benefits: LIDAR military applications: bomb drop, precision air drop, gunship ballistic winds correction, shipboard sensing and avoidance of turbulence. Commercial LIDAR applications: optimizing fuel savings, clear air turbulence detection. Non-LIDAR military applications: laser communication systems, active/passive target detection and tracking systems (e.g. EAGLE/AWACS), battlefield biological/chemical detection systems. Non-LIDAR commercial: Air/UAV and space-borne remote sensing systems, light weight, highly damped structural assemblies for microlithograpghy, CNC machining.