Characteristics of optical phase conjugation of picosecond pulsesin semiconductor optical amplifiers

摘要

Nondegenerate four-wave mixing (FWM) of picosecond optical pulsesnin semiconductor optical amplifiers is investigated theoretically,ntaking into account various carrier processes, probe depletion, andncross-gain modulation effects. Analytical solutions for greatlynsimplified coupled-wave mixing equations are obtained from whichnconditions where probe depletion and cross-gain modulation effectsncannot be neglected are found. On the other hand, the frequency detuningndependence of optimum input pump pulse energy and shaping of outputnconjugate pulses are observed from numerical simulations. In particular,ncalculations show that the frequency symmetry of conjugate and probenpulses with respect to the pump pulse does not hold for optical pulsenFWM. Two-photon absorption and ultrafast nonlinear refraction effectsnare shown to decrease the FWM conversion efficiency