title: Evaluation of polarized terahertz waves generated by Cherenkov phase matching.
abstract: We report terahertz (THz) wave generation by satisfying Cherenkov phase-matching condition in both s and p polarizations. A dual-wavelength optical parametric oscillator is constructed from two potassium titanium oxide phosphate crystals pumped by a frequency-doubled Nd:YAG laser. By rotating the orientation of both a lithium niobate crystal (LiNbO3) and the polarization of the pump waves, the polarization of the THz wave changes. Due to the difference in the refractive index and absorption, the output power for p polarization is one tenth that for s polarization. A tuning range from 0.2 to 6.5 THz is obtained for s polarization, and from 0.2 to 4.2 and 5.4 to 6.9 THz for p polarization. The extraction efficiency is improved by changing the angle of prism for p polarization, and a large phase change occurs at total internal reflection. Consequently, p-polarized THz waves are optimal for spectroscopic applications.
authors.forename: Takuya
authors.initials: T
authors.lastname: Akiba
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Akimoto
authors.forename: Koji
authors.initials: K
authors.lastname: Suizu
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Takashige
authors.initials: T
authors.lastname: Omatsu