New Performance Limits of an Ultrafast THz Photoconductive Receiver

Abstract

Common to all recently demonstrated optoelectronic sources of pulsed THz radiation has been the problem to properly characterize the source with receivers of limited bandwidths. To date the broadest bandwidth receiver has used ion-implanted, silicon-on-sapphire (SOS), photoconductive switches (1). Here, we report a new type photoconductive receiver with a measured response exceeding 6 THz. This receiver uses a new composite optoelectronic chip (shown in Fig. 1 a) consisting of an active layer of ion-implanted polysilicon on top of a thick thermal oxide on a high-resistivity silicon substrate. By using as the transmitter an identical receiver in a high-performance optoelectronic THz beam system, we were able to characterize the receiver with exceptional precision. Excellent agreement with a Drude theory model for the photoconductive response was obtained. © 1993 Optical Society of America