Abstract

In this work we investigate the dependence of the conjugate power on the pump power under high saturation. For a constant ratio between the output power of pump and probe, a recent theory¹ predicts that the conjugate power is proportional to the cube of the pump output if the optical nonlinearity responsible for the FWM process vanishes at transparency. If the optical nonlinearity does not vanish at transparency, the conjugate power is instead proportional to the cube of the pump output at low saturation and to the fifth power at high saturation. Among the physical mechanisms relevant to the optical nonlinearities in semiconductor amplifiers, carrier pulsations and spectral hole burning vanish at transparency, and carrier heating, two-photon absorption, and the instantaneous index nonlinearity induced by the optical Stark effect do not.

© 1995 Optical Society of America