Nonlinear gain effects on spectral dynamics in quantum well lasers

Abstract
A theoretical analysis is presented to show how nonlinear gain affects the spectral dynamics of quantum well (QW) lasers. The results indicate that the nonlinear gain, which is enhanced by the quantum confinement of carriers, causes an increase in the linewidth enhancement factor alpha . This enhancement of alpha results in spectral rebroadening: under high power output conditions. These properties should be taken into account when quantum well lasers are designed for highly coherent lasers.