Abstract

Electrical pulses of only 480-fs duration have been generated using polycrystalline films of CdTe grown by UV-enhanced metal organic chemical vapor deposition (MOCVD). The photoconductor was integrated in a coplanar transmission line with a 10-μm linewidth and spacing. The electrical pulses were generated in a sliding contact geometry and probed via reflection-mode electrooptic sampling in a small LiTaO₃ crystal dipped into the fringing fields of the transmission line. A pulse duration of 560-fs (FWHM) with a 490-fs rise time and a 450-fs 1 /e fall time was measured. Deconvoluting the response of the electroptic sampling technique, we arrive at a pulse duration of 480 fs. For comparison, an 830-fs duration (FWHM) was measured for a radiation-damaged silicon-on-sapphire (SOS) photoconductive switch in the same geometry, demonstrating the superior switching speed of MOCVD CdTe.

© 1988 Optical Society of America