title: Optimization of terahertz generation from LiNbO3under intense laser excitation with the effect of three-photon absorption.
abstract: We proposed a three-dimensional model to simulate terahertz generation from LiNbO3crystal under intense laser excition (up to ~50 mJ/cm2). The impact of three-photon absorption, which leads to free carrier generation and free carrier saturation (when pump fluence above ~10 mJ/cm2) 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.
authors.forename: Sen-Cheng
authors.initials: SC
authors.lastname: Zhong
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Zhai
authors.forename: Jiang
authors.initials: J
authors.lastname: Li
authors.forename: Li-Guo
authors.initials: LG
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Kun
authors.initials: K
authors.lastname: Meng
authors.forename: Qiao
authors.initials: Q
authors.lastname: Liu
authors.forename: Liang-Hui
authors.initials: LH
authors.lastname: Du
authors.forename: Jian-Heng
authors.initials: JH
authors.lastname: Zhao
authors.forename: Ze-Ren
authors.initials: ZR
authors.lastname: Li