Abstract

We have demonstrated previously that counterpropagating waves (with the same frequency) in a Kerr nonlinear medium with linear dispersion may become unstable when their intensities exceed certain threshold.¹ It has been shown recently² that the system exhibits large amplification when the pumping is below the threshold of instability. Here we explore the opportunity of using this system in optical amplification and show that its gain is appreciable even when linear absorption is taken into consideration. The mechanism of amplification in our system can be explained in terms of positive distributed feedback from the Kerr nonlinear index grating formed by two strong pumping laser waves.

© 1991 Optical Society of America