Degradation in injection lasers

The climb networks to be expected in an injection laser through 1) electromigration and 2) thermomigration are considered. It is shown that a model involving electromigration and dislocation pipe diffusion can explain the experimental results [1], [2], [7]. It is predicted that thermomigration may be important in optically pumped devices. It is further shown that elastic strain, per se, cannot be responsible for the degradation. Where numerical reduction is appropriate, parameters of the GaAs-Ga1-xAlxAs system are used. The activation energy for pipe diffusion in GaAs is estimated to be 0.75 eV and the process is believed to be controlled by the diffusion of arsenic vacancies.