MODELING THRESHOLD SHIFT OF POWER LASER-DIODES UNDER NEUTRONIC AND PHOTONIC IRRADIATION

The current threshold of high power GaAlAs laser arrays is shown to be strongly increased by fission neutron fluences, in the range 10(14) n /cm2. The current threshold after irradiation, whose value may be twic e that of the unirradiated device, is associated to an Anode - Cathode voltage displacement. After having proved these effects are neutron s pecific effects, we shall propose a simplified diffusion model, which takes into account both the electrical and electro-optical threshold e ffects. Distributed trapped charges are assumed to modify the carrier profiles inside the active layer. Simulation configurations are descri bed, with fitting results, and we conclude that a trapped charge densi ty in the 10(14) cm-3 range may be justified.