Alternating high-voltage biasing for terahertz large-area photoconductive emitters

High-voltage biasing is necessary for efficient generation of terahertz radiation using large-area photoconductive emitters and for electric-field-oriented charge-transfer studies. Coherent detection of terahertz pulses allows ac biasing to be the basis of modulation for lock-in detection. Biasing emitters with an ac field also removes the need for a complete conduction path. The experimental advantages of this approach along with a simple resonant method of generating the high-voltage bias applicable to higher-repetition-rate (up to a few hundred kilohertz) regeneratively amplified systems are described. (c) 2006 American Institute of Physics.