不同晶面与掺杂的ZnO晶体的超快三阶光学非线性  

Ultrafast Third-Order Optical Nonlinearity of ZnO Crystals with Different Crystal Planes and Doping

作　　者：王铭凯 肖政国 聂仲泉 Wang Mingkai;Xiao Zhengguo;Nie Zhongquan(Key Laboratory of Advanced Transducers and Intelligent Control,Ministry of Education and Shanxi Province,Taiyuan University of Technology,Taiyuan 030002,Shanxi,China;College of Physics and Optoelectronics,Taiyuan University of Technology,Taiyuan 030002,Shanxi,China;Department of Physics and Electronic Engineering,Tongren University,Tongren 554300,Guizhou,China)

机构地区：[1]太原理工大学新型传感器与智能控制教育部与山西省重点实验室,山西太原030002 [2]太原理工大学物理与光电工程学院,山西太原030002 [3]铜仁学院物理与电子工程系,贵州铜仁554300

出　　处：《激光与光电子学进展》2023年第19期163-171,共9页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(11974258,11604236);山西省重点研发计划(高新领域)(201903D121127);山西省高等学校科技创新项目(2019L0151);贵州省科技厅基金(黔科合基础-ZK[2021]一般031)。

摘　　要：研究了不同晶面与掺杂的ZnO晶体在飞秒线/径向偏振光(330 fs,532 nm)激发下的超快三阶光学非线性效应。首先,采用紫外/可见吸收光谱对ZnO晶体的带隙进行分析;然后,基于Z-Scan技术在飞秒线/径向偏振光条件下测试了ZnO晶体的三阶光学非线性特性。结果表明:在线偏振光和径向偏振光激发下,不同晶面和掺杂的ZnO晶体均呈现出非线性饱和吸收效应和自聚焦效应,由ZnO晶体中缺陷态的电子跃迁导致。飞秒线偏振光激发时,ZnO[101]的三阶光学非线性效应最强,由ZnO晶体中变窄的能量带隙引起的近共振增强的三阶光学非线性导致;而在径向偏振光激发下,ZnO[110]的三阶光学非线性最强,这可能是由较窄的能量带隙和飞秒矢量激光的轴对称偏振产生的各向异性非线性共同作用造成。本研究结果在可饱和吸收体、超快光场调控与超分辨成像等领域具有潜在的应用价值。In this study,ultrafast third-order optical nonlinearity of ZnO crystals with different crystal planes and doping under femtosecond linearly/radially polarized light(330 fs,532 nm) excitation is investigated.First,the band gap of ZnO crystals is analyzed using an ultraviolet-visible spectroscopy absorption spectrum.Next,the third-order optical nonlinearity of the ZnO crystals under femtosecond linearly/radially polarized light is measured using the Z-scan technique.The results show that the nonlinear saturation absorption effect and self-focusing effect are observed in ZnO crystals with different crystal planes and doping under the excitation of linearly and radially polarized lights owing to the electron transition in the defect state of the ZnO crystals.The third-order optical nonlinearity of ZnO[101] is the strongest for femtosecond linearly polarized light excitation,owing to the third-order optical nonlinearity of near-resonance enhancement caused by the narrowed energy bandgap in ZnO crystals.However,under the excitation of radially polarized light,ZnO[110] has the strongest third-order optical nonlinearity,probably owing to the combination of the narrow energy bandgap and the anisotropic nonlinearity caused by the axisymmetric polarization of the femtosecond vector laser.This study has potential application value in saturable absorbers,ultrafast light field regulation,and super-resolution imaging.

关 键 词：非线性光学 ZNO晶体 径向偏振光 饱和吸收 自聚焦 

分 类 号：O437[机械工程—光学工程]