Photoconductive connected array: A novel solution for pulsed terahertz radiation

Abstract

A novel design of an optically pumped THz photoconductive source in array configuration is presented. The proposed solution is based on the exploitation of the ultrawide band properties of connected antenna arrays. The photoconductive elements of the array are excited by an array of microlenses which splits and focuses the laser beam onto the active areas of the connected array. An ad-hoc DC biasing solution is introduced in order to properly bias the array elements; thus, realizing a connected array of photoconductive sources. If needed, the array can be used to illuminate a dielectric lens, which collimates the radiated THz electromagnetic field in the boresight direction. The proposed solution allows to achieve a high radiated power on a large bandwidth in the terahertz regime when the photoconductive material is illuminated by a laser operating in the pulsed mode. The proposed solution is therefore suitable and effective to be employed in terahertz timedomain systems.