Rapid Degradation in Double-Heterostructure Lasers. I. Proposal of a New Model for the Directional Growth of Dislocation Networks

Abstract

A new model of the generation of the dislocation network associated with dark-line-defects (DLDs) in rapidly degrading double-heterostructure laser crystals is proposed. The degradation can also be explained by this model, i.e., it may be associated essentially with the first stage of the development of the dislocation network which is based on the conservative propagation of screw dislocation segment and, thus, does not require point defect sources. The second stage of the development may be the widening and twisting of the trace of the dipole dislocation by a combination of climb and glide. The image of DLDs would thicken after the second stage of the development. The observed characters of DLDs such as directionality, existence of loops, and so on, can be well explained in the light of the new model.