Anistropy and broadening of optical gain in a GaAs/AlGaAs multiquantum-well laser

Anisotropic property and spectral broadening of the optical gain in a GaAs/AlGaAs multi-quantum-well (MQW) laser were precisely measured and compared with theoretical calculation to acquire a profitable model for designing of MQW lasers. The anisotropic property was well explained with calculation of allowable orientation of the electron wave. The broadening of the gain spectrum was also well explained by taking into account effect of the intraband relaxation of the electron wave. The threshold current density in the MQW structure was theoretically estimated based on the model to be lower than A/cm².