The formation of dark-area defects along the active stripe of buried heterostructure multi quantum-well lasers, in electroluminescence and photoluminescence images after degradation, was found to be related to dislocations lying along [011]. These dislocations were a consequence, rather than a cause, of the degradation. Jogs along [011] dislocations implied the presence of point defects in the active stripe. The nature of these point defects was unclear, but Zn was suggested to be a possible candidate.

Degradation of InGaAsP/InP-Based Multiquantum-Well Lasers T.Kallstenius, J.Bäckström, U.Smith, B.Stoltz: Journal of Applied Physics, 1999, 86[5], 2397-406