Guo Sheng-Ping, Cheng Xiyue, Sun Zong-Dong, Chi Yang, Liu Bin-Wen, Jiang Xiao-Ming, Li Shu-Fang, Xue Huai-Guo, Deng Shuiquan, Duppel Viola, Köhler Jürgen, Guo Guo-Cong
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, P. R. China.
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter CAS, Fuzhou, Fujian, 350002, P. R. China.
Angew Chem Int Ed Engl. 2019 Jun 11;58(24):8087-8091. doi: 10.1002/anie.201902839. Epub 2019 May 8.
A big challenge for nonlinear optical (NLO) materials is the application in high power lasers, which needs the simultaneous occurrence of large second harmonic generation (SHG) and high laser induced damage threshold (LIDT). Herein we report the preparation of a new Ga Se phase, which shows the SHG intensities of around 2.3 times and the LIDT of around 16.7 times those of AgGaS (AGS), respectively. In addition, its IR transparent window ca. 0.59-25 μm is also significantly wider than that of AGS (ca. 0.48-≈11.4 μm). The occurrence of the strong SHG responses and good phase-matching indicate that the structure of the new Ga Se phase can only be non-centrosymmetric and have a lower symmetry than the cubic γ-phase. The observed excellent SHG and phase-matching properties are consistent with our diffraction experiments and can be well explained by using the orthorhombic models obtained through our high throughput simulations.
非线性光学（NLO）材料面临的一个重大挑战是在高功率激光器中的应用，这需要同时具备大的二次谐波产生（SHG）和高的激光诱导损伤阈值（LIDT）。在此，我们报告了一种新的GaSe相的制备，其SHG强度约为AgGaS（AGS）的2.3倍，LIDT约为AGS的16.7倍。此外，其红外透明窗口约为0.59 - 25μm，也明显宽于AGS的（约0.48 - ≈11.4μm）。强SHG响应和良好的相位匹配的出现表明，新的GaSe相的结构只能是非中心对称的，并且比立方γ相具有更低的对称性。观察到的优异SHG和相位匹配特性与我们的衍射实验一致，并且可以通过使用通过高通量模拟获得的正交晶系模型得到很好的解释。
