Generation and measurement of ultrashort current pulses with Josephson devices

Experimental demonstration of an ultrashort-pulse generator and a novel sampling technique to measure its pulse shape is reported. The pulse generator, which uses Josephson interferometers, is designed to be dc powered and self-resetting. Its pulses are measured to be 26 ps in duration at a simulated maximum frequency of 2.5 GHz. The sampling technique is useful for measuring general fast waveforms with unprecented sensitivity and resolution extendable to subpicosecond time scale.