Frozen wave generation of bandwidth-tunable two-cycle THz radiation

Abstract

We report on the application of a photoconductive frozen wave generator (FWG) for the generation of 0.36-THz radiation. Through the excitation of a bipolar photoconductive array, a two-cycle THz electrical transient is created. The THz electrical transient occurs on a time scale much shorter than the carrier lifetime in the semiconductor. Furthermore, variations in the uniformity of the optical excitation intensity across the photoconductive array introduce a controlled THz temporal chirp, thus providing for fine bandwidth tunability of the device. Modeling of the FWG is successful in describing both the time variation and the amplitude spectrum of the photogenerated THz radiation.

Generation of 1.2 ps electrical pulses through parallel gating in ultrathin silicon photoconductive switches

“…Analogously, recombination-independent conduction current driven switching techniques have also been proposed 9 and demonstrated. 2,10,11 The PC geometries for these devices allow the optical excitation pulse to control both the generation and termination of the electrical signal through full illumination of the PC gap, eliminating the alignment sensitivity issues associated with edge illumination.…”