Study on physical mechanism of terahertz generation of GaP based on the analysis of polariton

Abstract

The physical mechanism of terahertz-wave generated from nonlinear crystal GaP was discussed based on polariton. The method which predicted to generate terahertz-wave in nonlinear crystal were reported. The polariton dispersion curve was physical basis of which terahertz-wave was generated from nonlinear crystal. The polariton dispersion curve of GaP crystal was depicted by using density functional theory and the polariton dispersion relation. The corresponding frequency of part polariton dispersion curve for GaP were between 2.5 THz-9.1 THz when small scattering angle about 2-11 degree were required. Namely, it showed theoretically that terahertz-wave with a range of 2.5-9.1 THz were generated from GaP crystal.