Waveguide coupled terahertz photoconductive antennas: Toward integrated photonic terahertz devices

Abstract

We demonstrate the operation of a low temperature GaAs photoconductive antenna pumped via a monolitically integrated AlGaAs based dielectric waveguide using 100fs pulses at 860nm. This technology demonstrates the feasibility of monolithically integrating dielectric waveguides and fast photoconductivity terahertz materials. We also demonstrate convenient pumping normal to the surface of the waveguide device via a surface grating coupler fabriacted using a gallium focused ion beam. Our initial results show a ∼10% optical coupling efficiency into the photomixer element. We attribute this low coupling efficiency to unoptimized processing techniques.