卤素硼酸盐深紫外非线性光学材料的低温合成及性能研究

深紫外非线性光学晶体可以输出波长小于200纳米的激光，在激光科学与技术领域受到广泛关注。氟硼酸盐是一类重要的深紫外非线性光学材料，通常采用高温固相法合成。本项目采用低温水热/溶剂热法，系统考察反应变量，在硼酸盐体系中引入卤素离子，得到低温相卤素硼酸盐晶体。总结结构特征与组装规律，建立和发展水热/溶剂热合成晶态卤素硼酸盐的新路径。对具有非中心对称结构的卤素硼酸盐，测试其二阶非线性光学性能，筛选出性能优良的卤素硼酸盐深紫外非线性光学材料。在此基础上，进一步进行理论计算研究，揭示卤素硼酸盐晶体结构、非线性光学性能与能带结构之间的内在关系，为合成性能优良的深紫外非线性光学材料提供科学依据。

Deep-ultraviolet (deep-UV) nonlinear optical (NLO) materials, which can produce coherent light of wavelengths below 200 nm, play a unique and crucial role in laser science and technology. Deep-UV NLO fluorooxoborates usually obtained under high-temperature solid-state condition. In this project, a series of novel halide-contained borates of low temperature phases will synthesize and characterize under hydro/solvothermal conditions. We will summarize their structural features and the assembly rule, and finally develop a new way to prepare crystalline halide-contained borates under low temperature. Furthermore, we will study the NLO properties of noncentrosymmetric halide borates, and calculate the electronic band structures to better understand the structure-property relation and the origin of the second-harmonic-generation response, and finally provide scientific basis to obtain new deep-UV NLO halide borates.