Scaled Atmospheric Blooming Experiments (SABLE)

II The SABLE field experiments investigated the use of phase-conjugate adaptive optics to compensate for strong thermal blooming and turbulence. The experiments, conducted at the TRW Capistrano Test Site in southern California over horizontal paths of 100 and 400 m, were designed to explore issues related to the propagation ofhigh-power lasers from the ground to space. The laser used in the experiments was the 10-kW hydrogen-fluoride (HF) Alpha Verification Module (AVM). Considerable diagnostic instrumentation was incorporated into SABLE to enable detailed measurements of the characteristics of the beam at both ends of the propagation path, the atmosphere along the path, and the adaptive optics system. The measurements were used both to interpret the experimental results and to test the accuracy of MOLLY, a four-dimensional computer propagation code developed at Lincoln Laboratory. SABLE demonstrated that (1) phase-conjugate adaptive optics can successfully compensate for severe blooming in the real atmosphere over a wide range of atmospheric conditions, (2) wind variations suppress the phase-compensation instabllity (PCl) and improve system performance significandy, and (3) the computer propagation code can accurately predict system performance for adaptive optics compensation of turbulence and severe thermal blooming in the real atmosphere.