Defect signatures in degraded high power laser diodes

Degradation of high power laser diodes is related to defect formation in the active parts of the laser. Extended defects can develop both at the facets, and inside the cavity. Their characterization is necessary for understanding the mechanisms driving the degradation. Cathodoluminescence is very useful for studying defects in degraded lasers. The main degradation mechanisms are discussed, supported by a thermomechanical model.