Compensation of the influence of temporal phase fluctuations in atmospheric optical-heterodyne data transmission systems

The efficiencies of various methods of detection of an optical signal were compared over an atmospheric 500-m path at the wavelength of 10.6 μ. The methods investigated were direct detection, heterodyne detection without compensation of the influence of temporal phase fluctuations, and heterodyne detection with such compensation. The measurements were carried out for a single aperture and also in the case of spatially separate detection by two apertures. It was found that compensation reduced considerably the probability of an error.