Coupled-Mode Theory for Cherenkov-Type Guided-Wave Terahertz Generation Via Cascaded Difference Frequency Generation

Author

Pengxiang Liu ; Degang Xu ; Hong Yu ; Hao Zhang ; Zhongxiao Li ; Kai Zhong ; Yuye Wang ; Jianquan Yao

Author_Institution

Inst. of Laser & Optoelectron., Tianjin Univ., Tianjin, China

Volume

31

Issue

15

fYear

2013

fDate

Aug.1, 2013

Firstpage

2508

Lastpage

2514

Abstract

A scheme for monochromatic terahertz (THz) generation via cascading enhanced Cherenkov-type difference frequency generation (DFG) in a sandwich-like waveguide is proposed. The novel scheme has the potential to overcome the quantum-defect limit and to provide an efficient output coupling. This process is elucidated by developing a coupled-mode theory and taking into account the pump depletion, waveguide mode properties, and THz output coupling. The effect of cascading enhancement is analyzed by comparing with non-cascaded DFG situation. It is predicted that THz power can be boosted by nearly 8-fold with a 400 MW/cm² pump in a 40-mm-long Si-LiNbO₃-Si waveguide.

Keywords

coupled mode analysis; elemental semiconductors; lithium compounds; microwave photonics; optical couplers; optical frequency conversion; optical pumping; optical waveguides; quantum optics; silicon; terahertz wave generation; Cherenkov-type guided-wave terahertz generation; Si-LiNbO₃-Si; THz output coupling; cascaded difference frequency generation; coupled-mode theory; monochromatic terahertz generation; pump depletion; quantum-defect limit; sandwich-like waveguide; size 40 mm; waveguide mode properties; Absorption; Couplings; Laser excitation; Mathematical model; Optical frequency conversion; Optical waveguides; Cascaded frequency down-conversion; Cherenkov phase-matching; difference frequency generation; optical waveguide; terahertz generation;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2013.2268876

Filename

6532358