All-weather long-wavelength infrared free space optical communications

Long-wavelength infrared radiation possesses superior transmission through common atmospheric problems such as fog, clouds, and smoke than the shorter wavelength laser sources in use today. Recent improvements in LWIR laser and modulator design makes possible reliable optical replacements for radio and microwave communications links in many applications. This paper describes components and techniques developed for high-speed, full-duplex all-weather infrared communications systems.