Gain and Index Measurements in GaAlAs Quantum Well Lasers

Measurements of the modal gain and group index in GaAlAs single quantum well (SQW) lasers are presented. The elimination of substrate emission has allowed accurate results to be obtained even in the near bandgap and below bandgap spectral regions. Substantial lifetime broadening is observed, and the gain smoothly goes to zero as the bandgap is approached. The group velocity index measurements indicate a dispersion of—3.44μm-1. © 1990 IEEE