Defect structure introduced during operation of heterojunction GaAs lasers

The nature and origin of the defects responsible for the rapid degradation of stripe geometry GaAs–GaAlAs double‐heterostructure lasers have been identified by transmission electron microscopy. These defects are formed by a three‐dimensional dislocation network which originates at a dislocation crossing the GaAlAs and GaAs epilayers. The propagation of the dislocation network takes place by a climb mechanism induced by the operation of the device.