Microwave switching by picosecond photoconductivity

Bulk photoconductivity produced by the absorption of picosecond optical pulses in silicon transmission-line structures has been used to switch and gate microwave signals. The technique permits the generation of microwave and millimeter-wave pulses as short as a single cycle, and requires only a few microjoules of optical energy. The basic features of the device are illustrated with switching experiments at 1 GHz and 10 GHz, and the results are discussed with reference to the physical properties of the high-density plasma responsible for the switching.