Terahertz emission based on large-area photoconductive emitters illuminated via beam interference

The use of beam interference in combination with large-area photoconductive emitters for the generation of pulsed terahertz radiation is presented. An interference pattern with a periode twice that of the terahertz emitter is generated with a transmission phase grating, placed directly in front of the photoconductive emitter. This way, efficient terahertz generation is achieved with a single metallization layer and a single lithography step in the fabrication technology of the THz emitter.