TRANSIENT EFFECTS IN FOUR-WAVE MIXING IN PHOTOREFRACTIVE PASSIVE PHASE CONJUGATE MIRRORS.

Partial differential equations are set up and solved partly analytically, partly numerically for the spatial and temporal variation of the amplitudes and phases of the four beams participating in four-wave mixing in a linear Passive Phase Conjugate Mirror. The instantaneous frequency of the resonating beam is also determined. It is shown that the duration and main features of the transient regime are determined not only by the properties of the photorefractive crystal but also by the external optical circuit, in particular by the quality factor and detuning of the resonator.