Polarization-dependent gain-current relationship in (111)-oriented GaAs/AlGaAs quantum-well lasers

Detailed measurements of polarization-dependent gain-current characteristics have been carried out on (111)- and (100)-oriented GaAs/AlGaAs single-quantum-well lasers by using Hakki and Paoli’s method. Polarization-dependent gain-current characteristics have been found to strongly depend on the well width and the quantization direction. The saturation of gain with the injection current and the width of the gain spectrum depends on the well width, and they are also affected by the transition between the higher-order subbands. Experimental results of polarization-dependent spontaneous emission are also presented. The simple selection rule and the effective-mass theories do not quantitatively account for the experimental results.