Strain driven degradation in laser diodes

Improving the reliability of high power laser diodes is a crucial issue for their practical application. The understanding of the mechanisms behind the degradation of high power laser diodes is necessary to increase their power and lifetime. The study of the degradation mechanisms requires the investigation of the main defects generated during the laser degradation; therefore, an exhaustive examination of the defect signatures in the degraded devices must be crucial to establish reliable degradation scenarios. Cathodoluminescence (CL) is a unique tool to identify the main defects generated by the device degradation, which will permit to build up a model providing a comprehensive scenario of the laser degradation. CL images of the degraded devices reveal the presence of regions with low, or fully quenched, radiative activity, associated with the presence of extended defects in the active layers of the laser structure, in both the front facet and the cavity.