Addressing and control of high-speed logic circuits with picosecond light pulses

We demonstrate complete logic-level switching in high-speed GaAs field-effect transistor circuits addressed by picosecond light pulses, and logic-function control thereby. Besides their applicability to high-speed data processing in gigahertz-rate communication links, such experiments show potential for contactless diagnostic procedures for test circuits and for picosecond-resolution measurements of on-chip response times of logic gates by means of optical sampling techniques.