Effects of 1-MeV neutron irradiation on the operation of a bistable optically controlled semiconductor switch (BOSS)

Recent subnanosecond-opening results of the semiconductor switch (BOSS) bistable optically controlled are presented. The processes of persistent photoconductivity followed by photo-quenching have been demonstrated in copper-compensated, silicon-doped, semi-insulating gallium arsenide (GaAs:Si:Cu). These processes allow a switch to be developed that can be closed by the application of one laser pulse (λ=1.06 μm) and opened by the application of a second laser pulse with a wavelength equal to twice that of the first laser. The opening phase is a two-step process which relies initially on the absorption of the 2-13-μm laser and finally on the recombination of electrons in the conduction band with holes in the valance band. The second step requires a sufficient concentration of recombination centers in the material for opening to occur in the subnanosecond regime. This report discusses the effects of 1-MeV neutron irradiation on the BOSS material for the purpose of recombination center generation. Initial experiments indicated a reduction of the recombination time from several nanoseconds down to about 250 ps. Both experimental and theoretical results are presented