Terahertz (THz) wave detection and emission via Cherenkov-phase-matched nonlinear optical effects at 1.55-μm optical wavelength were demonstrated using a GaAs with metal-coating (M-G-M) and bare GaAs as a reference sample in conjunction with a metallic tapered parallel-plate waveguide (TPPWG). The metal-coated GaAs is superior to the bare wafer both as a THz electro-optic detector and as an emitter. Significant improvements in the detection and emission efficiency were obtained by utilizing a metal-coating due to better confinement and lower loss of the THz waves propagating in the M-G-M compared with bare GaAs.
Santos, R. D., Ozawa, S., Mag-usara, V., Azuma, S., Tuico, A., Copa, V., Salvador, A., Yamamoto, K., Somintac, A., Kurihara, K., Kitahara, H., Tani, M., & Estacio, E. (2016). Cherenkov-phase-matched nonlinear optical detection and generation of terahertz radiation via GaAs with metal-coating. Optics Express, 24(22), 24980–24988. https://doi.org/10.1364/OE.24.024980