Very Large Solar Rejection Filter for Laser Communication

Surface Optics Corporation (SOC) will develop a band pass filter comprised of a visible dielectric mirror and an induced transmission filter, applied to two sides of a cast polyimide membrane. The mirror/filter combination will block 95% of the incident solar radiation, while allowing a narrow pass-band for laser communication. The combination of a visible dielectric mirror constructed on one side of a membrane and a band-pass filter on the second surface, offers a means of creating a very efficient solar reflector with relatively few coatings layers. The exceptionally thin and flat optical substrate will minimize degradation of the laser signal. 2-meter membrane filters are sought by NASA to prevent over-heating of ground-based laser communication receivers operating during daylight hours. In Phase II, the designs will be scaled to large membrane substrates approximately 2-m in diameter.