Edge-coupled membrane terahertz photonic transmitters based on metal-semiconductor-metal traveling-wave photodetectors

Ultra-high-speed photodetectors and printed-circuit antennas construct photonic transmitters. In this letter, we demonstrate a terahertz (THz) photonic transmitter: edge-coupled membrane photonic transmitters based on metal-semiconductor-metal traveling-wave photodetectors, which are fabricated with low-temperature-grown GaAs photoabsorption layers. With a membrane-based and edge-coupled structure, the demonstrated photonic transmitters can eliminate the requirement of Si lenses and attain an over 20 times higher optical-to-THz power conversion efficiency 2 x 10(-4) than vertical illuminated photonic transmitters with Si lenses at the same operation frequency. (C) 2002 American Institute of Physics. [DOI: 10.1063/1.1533846].