Environmentally Adaptive Free-Space Optical Communication

Physical Sciences Inc. will develop an adaptive free-space optical communication system, capable of maintaining low bit error rate (~ 10-9) over long ranges (> 20 km) by correcting for atmospheric and other environmental factors while operating at eye-safe power levels.  The proposed concept uses three adaptive systems to optimize performance in the presence of platform motion, varying optical scattering/absorption, and atmospheric turbulence. In Phase I, PSI will combine atmospheric and adaptive optics modeling with basic lasercom link analysis to form a comprehensive system model, outputting predictions of BER under various atmospheric conditions.  A commercial atmospheric modeling code will be used to simulate background radiance and optical extinction from scattering/absorption losses in the optical channel.  Outputs will generate a library of values for different geographic locations, times of day, and atmospheric conditions.  Optical turbulence will be modeled by combining Fresnel diffraction with a highly accurate method for developing phase screens.  Adaptive hardware models will be integrated to assess performance improvements.  Our common-axis optical transceiver provides high optical throughput while minimizing size and weight.  Using PSI’s advanced adaptive optics model, combined with design and hardware experience, will result in a high-performance free-space optical system that is readily adaptable for real-world conditions.