Radiation resistance of GaAs-GaAlAs vertical cavity surface emitting lasers

The variations of the optical and electrical characteristics of a vertical cavity surface emitting laser based on GaAs quantum wells have been monitored versus irradiation with 1 MeV electrons. The results are understood by the introduction of nonradiative recombination centers in the wells whose characteristics, capture cross section for minority carriers times their introduction rate, can be determined. A similar study performed for proton irradiation shows that the results can be explained in the same way when the introduction rate of the defects is replaced by the proton energy loss into atomic collisions. These results allow us to deduce the equivalence between electron and proton irradiations: A flux of 1 proton cm(-2) which loses an energy E-n... (eV) into atomic collisions is equivalent to a fluence of about 9x10(-2) E-n... cm(-2), 1 MeV electrons. (C) 2005 American Institute of Physics.