Reception of scattered radiation by optical quantum amplifiers

A theory is devloped of the propagation of a spatially random signal, resulting from the scattering of coherent radiation, through a single-pass optical quantum amplifier. Attention is drawn to the need to allow for the channeling of the radiation by the walls of a gas-discharge cell. The spatial selectivity of optical quantum amplifiers is discussed. It is shown that the optimal size of the aperture of a receiver system with a single-pass amplifier may be considerably greater than the spatial coherence radius. Estimates are obtained for the scattered-radiation gain. The theoretical conclusions are confirmed by an experimental study.