Noise of thermal and hypersonic four-wave reversing mirrors and influence of wave mismatch

A theoretical analysis is made of the influence of the wave mismatch on the operational dynamics and sensitivity of four-wave hypersonic reversing mirrors. The minimum power of a weak signal at which this signal can be distinguished from the noise background of the mirror is determined. Conditions are found under which the sensitivity of a system consisting of a laser preamplifier and a four-wave hypersonic reversing mirror is close to the limit determined by the quantum noise of the laser amplifier. A theoretical analysis is made of the sensitivity of four-wave thermal reversing mirrors. This is used as the basis for a comparative analysis of the characteristics of thermal and hypersonic mirrors.