Use of a regenerative optical quantum amplifier in photodetection of scattered coherent radiation

An experimental investigation was made of the efficiency of a regenerative optical quantum amplifier in detection of scattered laser radiation. In agreement with theoretical estimates, the experimental results demonstrated that the average energy of the scattered field amplified in this amplifier did not exceed the energy in the spatial coherence area. The relative variance of the output signal, which was distributed exponentially under linear conditions, was close to unity and was independent of the relationship between the correlation radius of the spatially random field and the receiver aperture radius.