LiAlS_(2):一种具有超宽带隙和高激光损伤阈值的潜在红外频率转换材料  

LiAlS_(2): A promising infrared frequency-conversion material with ultrawide band gap and high laser-induced damage threshold

作　　者：李广卯 杨志华 潘世烈 Guangmao Li;Zhihua Yang;Shilie Pan(Research Center for Crystal Materials,CAS Key Laboratory of Functional Materials and Devices for Special Environments,Xinjiang Technical Institute of Physics&Chemistry,CAS,Urumqi 830011,China;Institution Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]Research Center for Crystal Materials,CAS Key Laboratory of Functional Materials and Devices for Special Environments,Xinjiang Technical Institute of Physics&Chemistry,CAS,Urumqi 830011,China [2]Institution Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Materials》2023年第3期1189-1196,共8页中国科学（材料科学（英文版）

基　　金：supported by the Key Laboratory Opening Foundation of Xinjiang Uygur Autonomous Region (2022D04013);the High-level Talent Project of Xinjiang Uygur Autonomous Region (2022D000039);the West Light Foundation of the Chinese Academy of Sciences (2019-YDYLTD-002);the National Natural Science Foundation of China (61835014 and 51972336);Xinjiang Major Science and Technology Project (2021A01001);the International Partnership Program of CAS (1A1365KYSB20200008);the Instrument Developing Project of CAS (GJJSTD20200007);the Science and Technology Service Network Initiative of CAS (KFJ-STS-QYZD-130).

摘　　要：具有宽带隙、高激光损伤阈值和无双光子吸收的红外非线性光学晶体材料在民用和军事领域具有许多重要应用.本工作通过系统的实验表征和全面的第一性原理研究了LiAlS_(2)晶体的综合光学性质.结果表明,LiAlS_(2)是一致熔融的晶体材料,在2.09μm光源下能够实现Ⅰ类相位匹配,倍频效应(SHG)和有效SHG系数均为AgGaS_(2)的0.2倍;LiAlS_(2)具有目前红外非线性光学晶体材料中最宽的光学带隙,为5.13 eV,激光诱导损伤阈值约为AgGaS_(2)的28倍.此外,对其折射率色散关系的研究发现,LiAlS_(2)为正双轴晶体,最短相位匹配波长为1.98μm;结构-性能关系分析表明[AlS_(4)]四面体决定了其光学带隙,同时是材料SHG响应的主要贡献来源.以上结果表明,LiAlS_(2)是一种潜在的能够在高能激光系统中应用的红外非线性光学材料.The development of infrared(IR) nonlinear optical(NLO) crystals could foster their wide applications in civil and military fields. Thus, IR NLO materials with a wide band gap, high laser-induced damage threshold, and lack of two-photon absorption are urgently needed. This work reports the comprehensive optical properties of LiAlS_(2)through systematic experimental characterizations and the first principle study. The results confirmed the congruently melting feature of LiAlS_(2), type-Ⅰ phase matching(PM) performance, and its second-harmonic generation(SHG) response(0.2 × AgGaS_(2) at2.09 μm). Notably, LiAlS_(2)shows the widest band gap of5.13 eV among the selected IR NLO materials and an ultrahigh laser-induced damage threshold about 28 times that of AgGaS_(2). The structure-property relationship analysis indicates that the [AlS_(4)] tetrahedra determine the optical band gap and primarily contribute to the SHG response. Moreover,the calculated effective SHG coefficient deff, the refractive index dispersion relation, and the shortest PM wavelength are reported. The results of this study indicate that LiAlS_(2) can be a promising IR NLO material in high-energy laser systems.

关 键 词：频率转换 激光诱导损伤阈值 倍频效应 激光损伤阈值 相位匹配 双光子吸收 晶体材料 双轴晶体 

分 类 号：O734[理学—晶体学]