Xia Mingjun, Tang Chuan, Li Rukang
Beijing Center for Crystal Research and Development, Key Laboratory of functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2019 Dec 9;58(50):18257-18260. doi: 10.1002/anie.201911324. Epub 2019 Oct 22.
Practical mid-infrared (MIR) coherent light beams generated by frequency conversion in nonlinear optical (NLO) crystals are indispensable in time-resolved infrared vibrational spectroscopy, remote light detection and ranging, and free-space communications. Herein, a new titanyl germanate Rb Li TiOGe O (RLTG) MIR NLO crystal was obtained by heavier element substitution. It features a complicated structure network composed of compressed TiO square pyramids and distorted GeO tetrahedra, separated by Rb and Li cations. More importantly, RLTG exhibits concurrently short ultraviolet (0.28 μm) and long IR (5.58 μm) transmittance cutoffs, fully covering the atmospheric transparent window of 3-5 μm. Related to the short UV cutoff, it shows a higher laser-induced damage threshold in comparison to commercial MIR NLO crystals, about twice that of KTiOPO (KTP) and 50 times that of AgGaS (AGS).
通过非线性光学（NLO）晶体中的频率转换产生的实用中红外（MIR）相干光束在时间分辨红外振动光谱、远程光探测与测距以及自由空间通信中不可或缺。在此，通过重元素取代获得了一种新型钛氧基锗酸盐RbLiTiOGeO（RLTG）中红外NLO晶体。它具有由压缩的TiO四方锥和扭曲的GeO四面体组成的复杂结构网络，由Rb和Li阳离子分隔。更重要的是，RLTG同时具有短紫外（0.28 μm）和长红外（5.58 μm）透射截止，完全覆盖了3 - 5 μm的大气透明窗口。与短紫外截止相关，与商用中红外NLO晶体相比，它显示出更高的激光损伤阈值，约为磷酸钛氧钾（KTP）的两倍，硫化镓银（AGS）的50倍。
