Broadband third-order optical nonlinearities of layered franckeite towards mid-infrared regime  

作　　者：Zhi-Qiang Xu Tian-Tian Zhou Jie Li Dong-Yang Liu Yuan He Ning Li Xiao Liu Li-Li Miao Chu-Jun Zhao Shuang-Chun Wen 徐志强;周甜甜;李洁;刘东阳;何源;李宁;刘潇;缪丽丽;赵楚军;文双春(Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices,School of Physics and Electronics,Hunan University,Changsha 410082,China;School of Mechanical and Electrical Engineering,Heze University,Heze 274015,China)

机构地区：[1]Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education&Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices,School of Physics and Electronics,Hunan University,Changsha 410082,China [2]School of Mechanical and Electrical Engineering,Heze University,Heze 274015,China

出　　处：《Chinese Physics B》2024年第10期275-281,共7页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.61975055);the Natural Science Foundation of Hunan Province,China(Grant No.2023JJ30165);the Natural Science Foundation of Shandong Province,China(Grant No.ZR2022QF005);the Doctoral Fund of University of Heze(Grant No.XY22BS14).

摘　　要：The study of nonlinear optical responses in the mid-infrared(mid-IR)regime is essential for advancing ultrafast mid-IR laser applications.However,nonlinear optical effects under mid-IR excitation are rarely reported due to the lack of suitable nonlinear optical materials.The natural van derWaals heterostructure franckeite,known for its narrow bandgap and stability in air,shows great potential for developing mid-IR nonlinear optical devices.We have experimentally demonstrated that layered franckeite exhibits a broadband wavelength-dependent nonlinear optical response in the mid-IR spectral region.Franckeite nanosheets were prepared using a liquid-phase exfoliation method,and their nonlinear optical response was characterized in the spectral range of 3000 nm to 5000 nm.The franckeite nanosheets exhibit broadband wavelengthdependent third-order nonlinearities,with nonlinear absorption and refraction coefficients estimated to be about 10^(-7)cm/W and 10^(-11)cm^(2)/W,respectively.Additionally,a passively Q-switched fluoride fiber laser operating around a wavelength of 2800 nm was achieved,delivering nanosecond pulses with a signal-to-noise ratio of 43.6 dB,based on the nonlinear response of franckeite.These findings indicate that layered franckeite possesses broadband nonlinear optical characteristics in the mid-IR region,potentially enabling new possibilities for mid-IR photonic devices.

关 键 词：third-order optical nonlinearities franckeite MID-INFRARED Q-SWITCHING 

分 类 号：O437[机械工程—光学工程]