Optical space communication. Review

Features of information exchange between satellites and satellites with ground stations and in the opposite direction are considered. The influence of such atmospheric factors as fog, rain, snow, atmospheric turbulence, background noise, and sky glow on the quality of information signals is analyzed. The expediency of using transmitter frequencies, which lie in the area of windows of the Earth transparency and are in the infrared region of the spectrum, has been established. In particular, generators of such frequencies in the near-infrared region can be InGaAs laser diodes, which are light in the region of about 1550 nm, and in the far-infrared region – cascade lasers, which are able to generate radiation in the range of 3.5 to 24 μm. InGaAs photodiodes and HgCdTe detectors should be used as receivers of the mentioned frequencies.