Fabrication and characterization of a quasi-phase-matched GaP optical device for terahertz-wave generation

A method of fabricating a quasi-phase-matched optical device with GaP for terahertz (THz)-wave generation is described, and its generation at 1 and 2.6 THz is demonstrated by employing difference-frequency generation pumped at 1.55 μm. The enhancement of the output THz-wave power due to the quasi-phase-matching effect is confirmed, and an order of magnitude larger output efficiency than that of an ordinary quasi-phase-matched device fabricated with LiNbO3 is obtained. Some important factors that affect the output characteristics of the GaP device are also discussed.