Investigation of the degradation of sealed electron-beam-pumped semiconductor lasers

An investigation was made of the causes of degradation of the active elements of sealed semiconductor GaAs lasers pumped transversely by electron beam pulses. Tests involving application of 5×10⁶ pulses under the usual pumping conditions indicated that the main factor which reduced the output radiation power was the optical self-damage of some parts of the laser crystal because of the pump inhomogeneities. Accelerated tests at the frequency 3 kHz involving application of up to 5×10⁷ pulses revealed fatigue damage to the active region of the laser crystal as a result of cyclic interaction with the electron beam and with the radiation emitted by the laser itself.