发光学报Issue(3)：361-365,5.DOI:10.3788/fgxb20153603.0361
GaSe晶体的双光子吸收对太赫兹输出的影响
Two-photon Absorption Attenuated THz Generation in GaSe
摘要
Abstract
The broadband THz generation from 0 . 2 to 2 . 5 THz was measured as a function of pump intensity in a single pure gallium selenide crystal based on the optical rectification of ultrafast laser pulses. Two-photon absorption at 800 nm can generate free charge carriers which can absorb the generated THz radiation, and finally attenuate THz output. The result indicates that the pump inten-sity dependence of ouput THz radiation changes from square to sub-linear relationship and the satu-ration of output THz radiation appears at high pump intensity. To study the impact of two photon ab-sorption on THz generation, the two photon absorption coefficient of GaSe at 800 nm is measured to be 0. 165 cm/GW, which is determined by the measured nonlinear transmission. The THz output fitting result taking account of the free charge carrier absorption cross section of 1 × 10 -15 cm2 is con-sistent with the experiment data very well. This estimation result can be used to optimize the conver-sion efficient of THz generation in GaSe crystal under intense laser pump.关键词
GaSe晶体/双光子吸收/太赫兹/吸收截面Key words
GaSe crystal/two photon absorption/THz generation/absorption cross section分类
数理科学引用本文复制引用
姜可,谢冀江,杨贵龙,谢京江,李殿军,陈飞..GaSe晶体的双光子吸收对太赫兹输出的影响[J].发光学报,2015,(3):361-365,5.基金项目
激光与物质相互作用国家重点实验室开放基础研究课题(SKLLIM1012)资助项目 （SKLLIM1012）
