Saturation effects in the carrier-induced refractive index in a semiconductor gain medium

We derive expressions for the loaded gain and carrier-induced refractive-index change for a semiconductor gain medium. Our main conclusion is that the loaded gain and the loaded carrier-induced refractive-index change saturate differently, with the index being a much weaker function of the laser flux. This has important implications for the laser mode structure above threshold and is particularly important for filamentation suppression and stability in numerical modeling studies of gain-guided structures. © 1987 Optical Society of America.