Widely Tunable, Monochromatic THz Generation via Cherenkov-Type Difference Frequency Generation in an Asymmetric Waveguide

Author

Pengxiang Liu ; Degang Xu ; Weipeng Wang ; Changming Liu ; Sujia Yin ; Xin Ding ; Yuye Wang ; Jianquan Yao

Author_Institution

Key Lab. of Opto-Electron. Inf. & Tech. Sci. (Minist. of Educ.), Tianjin Univ., Tianjin, China

Volume

49

Issue

2

fYear

2013

fDate

Feb. 2013

Firstpage

179

Lastpage

185

Abstract

Cherenkov-type monochromatic terahertz (THz) generation via difference frequency generation in a general asymmetric sandwich-like waveguide is investigated theoretically. An efficient geometry-conversion from a transverse electric (TE) pump mode to a TE THz mode is mainly considered. The general expression for a Cherenkov THz field is obtained by solving the nonlinear wave equation analytically. Numerical simulation is performed on specific devices with three typical substrate materials: 1) nondoped LiNbO₃; 2) BK7 glass; and 3) quartz. Characteristics of this type of THz source and parametric dependence of conversion efficiency are discussed. It is predicted that the conversion efficiency would be increased by one order by optimizing the waveguide structure.

Keywords

lithium compounds; optical frequency conversion; optical glass; optical waveguides; quartz; terahertz wave generation; wave equations; BK7 glass; Cherenkov-type difference frequency generation; LiNbO₃; TE terahertz mode; conversion efficiency; general asymmetric sandwich-like waveguide; geometry-conversion; monochromatic terahertz generation; nonlinear wave equation; quartz; transverse electric pump mode; Frequency conversion; Nonlinear optics; Optical pumping; Optical waveguides; Substrates; Cherenkov phase matching; difference frequency generation; optical waveguide; terahertz generation;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/JQE.2012.2234438

Filename

6384643