Abstract

Photoconductive antennas¹ have been standard devices for detecting pulsed electromagnetic radiation in the terahertz (THz) frequency range. When it comes to imaging with THz waves, however, the competing method of free-space electro-optic sampling⁵ has a very significant speed advantage because it can use commercial CCD cameras for recording many data points at virtually the same time, while recording THz images with photoconductive antennas relies on time-consuming mechanical lateral scanning. In order to speed up this scanning process, we aim at THz imaging with one- and two- dimensional arrays of photoconductive antennas. As with a CCD camera, many data points could then be taken at the same time (as many as antennas in the array), but a data storage would also be needed for every antenna. Conventional antenna read-out electronics are usually based on lock-in amplifiers and are bulky and relatively expensive equipment, not suitable for detection in arrays. In this paper we present a simple, small and inexpensive read-out circuit that can be used in large numbers and is convenient for reading out signals from arrays of photoconductive antennas.

© 2002 Optical Society of America