Broadening of the below-threshold near-field profile of GaAs quantum-well lasers due to photon recycling

摘要

The subthreshold near-field profile of single quantum well laser diodes was studied experimentally and theoretically. Wide gain-guided stripes as well as single lateral mode ridge-waveguide diodes mere investigated. In both types of device, the measured width of the near-field was significantly wider than the width predicted by the conventional theory which includes ambipolar carrier diffusion as the only spatial broadening mechanism. A new model that invokes close to 100% efficient photon recycling was developed to explain the observed near-field profiles.