Inaccuracy of reproduction of the spatial structure of a beam in a laser amplifying medium with a reversing mirror

An analysis is made of the influence of inhomogeneities of the gain and refractive index of an active medium of a double-pass amplifier with an ideal wavefront-reversing mirror on the accuracy of reproduction of spatial distributions of the amplitude and phase of the input signal. It is shown that if inhomogeneities of the refractive index are sufficiently small and an amplifier can be regarded as a thin lens (phase corrector), the wavefront of the output radiation is reversed relative to the wavefront of the input signal. If these conditions are not satisfied, reversal does not take place.