EFFECTS OF 1-MEV NEUTRON-IRRADIATION ON THE OPERATION OF A BISTABLE OPTICALLY CONTROLLED SEMICONDUCTOR SWITCH (BOSS)

Recent subnanosecond-opening results of the bistable optically control led semiconductor switch (BOSS) are presented. The processes of persis tent photoconductivity followed by photo-quenching have been demonstra ted in copper-compensated, silicon-doped, semi-insulating gallium arse nide (GaAs:Si:Cu). These processes allow a switch to be developed that can be closed by the application of one laser pulse (lambda = 1.06 mu m) and opened by the application of a second laser pulse with a wavele ngth equal to twice that of the first laser. The opening phase is a tw o-step process which relies initially on the absorption of the 2-13-mu m laser and finally on the recombination of electrons in the conductio n band with holes in the valance band. The second step requires a suff icient concentration of recombination centers in the material for open ing to occur in the subnanosecond regime. This report discusses the ef fects of 1-MeV neutron irradiation on the BOSS material for the purpos e of recombination center generation. Initial experiments indicated a reduction of the recombination time from several nanoseconds down to a bout 250 ps. Both experimental and theoretical results are presented.