Method of evaluating facet and bulk degradation in semiconductor lasers

Abstract A new method has been proposed to evaluate bulk (crystal) and facet degradation in semiconductor lasers separately by cleaving the degraded laser diodes into three regions along a resonator direction. By applying the method to AlGalnP visible light laser diodes, it has been demonstrated that it is possible to evaluate the changes in facet reflectivity and the effects of bulk and facet degradation on performance characteristics of as‐cleaved laser diodes as well as laser diodes with antirefiection and high‐reflection (AR‐HR) facet coating.