Dc. Stoudt et al., BISTABLE OPTICALLY CONTROLLED SEMICONDUCTOR SWITCHES IN A FREQUENCY-AGILE RF SOURCE, IEEE transactions on plasma science, 25(2), 1997, pp. 131-137
The processes of persistent photoconductivity followed by photoquenchi
ng have been demonstrated at megawatt power levels in copper-compensat
ed, silicon-doped, semi-insulating gallium arsenide, These processes a
llow a photoconductive switch to be developed that can be closed by th
e application of one laser pulse (lambda = 1.06 mu m) and opened by th
e application of a second laser pulse with a wavelength equal to twice
that of the first laser (lambda = 2.13 mu m). This switch is called t
he bistable optically controlled semiconductor switch (BOSS), The open
ing phase of the BOSS requires a sufficient concentration of recombina
tion centers (RC) in the material for opening to occur in the subnanos
econd regime. These RC's are generated in the bulk GaAs material by fa
st-neutron irradiation (similar to 1 MeV). Neutron-irridated BOSS devi
ces have been opened against a rising average electric field of about
36 kV/cm (18 kV) in a time less than 1 ns while operating at a repetit
ion rate, within a two-pulse burst, of about 1 GHz. The ability to mod
ify the frequency content of the electrical pulses, by varying the tim
e separation, is demonstrated, Results demonstrating the operation of
two BOSS devices imbedded in a frequency-agile RF source configuration
are also discussed.