Application of Sub-wavelength Grating Electrodes in Photo Conductive Antennas

Terahertz waves have great scientific value and broad application prospects, in which the key technology is the generation of terahertz waves. Photoconductive antennas (PCA) are one of the main methods to generate terahertz waves, but lower radiation efficiency limits the further development. A sub-wavelength grating electrode structure is utilized, which employ extraordinary optical transmission (EOT) phenomenon, to enhance photoelectric conversion efficiency, therefor generating high-power, high-energy terahertz wave. First, groove-slit transmission is analyzed to guide the design of grating electrode. Then, parameters of sub-wavelength grating electrode are analyzed and optimized under 2D, which is compared with traditional and plasma PCA. Results show that the sub-wavelength grating electrode can significantly enhance the transmission field.