Open AccessOptimization of terahertz generation from LiNbO_3 under intense laser excitation with the effect of three-photon absorption
Author(s) -
Sen-Cheng Zhong,
Zhangyin Zhai,
Jiang Li,
Li-Guo Zhu,
Jun Li,
Kun Meng,
Qiao Liu,
Liang-Hui Du,
Jun Zhao,
Zeren Li
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.031313
Subject(s) - terahertz radiation , optics , laser , materials science , fluence , absorption (acoustics) , excitation , pulse duration , attenuation coefficient , terahertz spectroscopy and technology , optoelectronics , physics , quantum mechanics
We proposed a three-dimensional model to simulate terahertz generation from LiNbO 3 crystal under intense laser excition (up to ~50 mJ/cm 2 ). The impact of three-photon absorption, which leads to free carrier generation and free carrier saturation (when pump fluence above ~10 mJ/cm 2 ) on terahertz generation was investigated. And further with this model, we stated the optimized experimental conditions (incident postion, beam diameter, and pulse duration, etc) for maximum generation efficiency in commonly-used tilted-pulse-front scheme. Red shift of spectrum, spatial distribution "splitting" effects of emitted THz beam, and primilary experimental verification under intense laser excitation are given.