Photoconductive gating of picosecond electrical pulses on thinned-silicon substrates

By fabricating a microstrip photoconductive switch on a thinned-silicon substrate, of a thickness less than the penetration depth of the excitation radiation, it is found that ultrashort electrical pulses can be generated. The optical excitation pulse is responsible for both ´turning on´ and later ´turning off´ the electrical transient, eliminating the necessity for an ultrashort carrier lifetime in the semiconductor substrate.