Optical phase conjugation with smooth pump profiles.

'19 ABSTRACT (Continue on reverse if necessay ano identity by block number) We present analytical results for the steady-state signal and phase-conjugate fields interacting with smoothly varying nondepleted pump waves in a nearly degenerate four-wave-mixing geometry. Signal depletion is retained in the equations and we study the effect that detuning on the input signal from the degenerate pump amplitudes has on the reflected conjugate wave and the transmitted signal wave. A general result is derived for the appearance of spontaneou, amplification under weak restrictions on the profile of the degenerate pump fields. The conju gation of the phase front of the signal is studied for exponential and hyperbolic secant functions multiplying the coupling coefficients and comparison is made with corresponding results for square profile pump fields. These results are discussed and their relevance to phase conjugation of pulses is examined.