短波长非线性光学晶体硼酸铯钡生长及性能研究

Nonlinear optical crystal is an important material foundation of optic-electronic industry. It has a wide application prospect in industry and national defense. In particular, UV-double crystal is the core material for short wave laser source, so it is urgent to investigate it. . The KBe2BO3F2 crystal is a new vacuum ultraviolet nonlinear optical crystal discovered by scientists in China. It is the only nonlinear optical crystal with 1064 nm laser output of 177.3 nm. Based on the structure model of KBBF, the BO4 tetrahedron was replaced by the BeO3F tetrahedron, cesium barium borate crystal was found by us for the first time in the world. Its powder frequency effect is about 3 times that of KDP and its UV cutoff edge is 175 nm. And the birefractive index of 589.3 nm is about 0.08, which is expected to be a new generation of ultraviolet nonlinear optical materials. On this basis, the phase equilibrium of BaO-B2O3-Cs2O and its related systems will be studied. In order to obtain large size, high quality single crystal, its crystal growth flux system and growth technology will be explored; system viscosity and other shortcomings will be overcome. The linear and nonlinear optical properties will be tested and the direct four-harmonic generation output of 266 nm laser will be realized. The relationship between crystal structure and optical properties will be studied. The application prospect in ultraviolet region will be evaluated..The successful development of this crystal will enrich the theory system of nonlinear optical material design and synthesis, and will help promote the development of the all-solid ultraviolet and deep ultraviolet laser to practical use and industrialization.

紫外、深紫外倍频晶体是产生短波激光光源的核心材料，在工业、国防等领域具有广泛的应用前景，因此迫切需要深入研究。.KBe2BO3F2晶体是目前唯一能实现1064nm激光六倍频177.3nm 输出的非线性光学晶体。基于KBBF结构模型，设计将BO4替代其中BeO3F，在国际上首次发现硼酸铯钡晶体，粉末倍频效应为3KDP，紫外截至边达175nm，测得589.3nm处双折射率约为0.08，有望成为新一代短波长倍频晶体。在此基础上，本项目将进一步研究相关体系相平衡关系；探索晶体生长助熔剂体系及生长工艺，克服晶体生长体系粘度大等难点，获得大尺寸、高质量单晶；测试光学性能，实现266nm激光的直接四倍频输出；研究晶体结构与光学性能的关系；评估其在紫外、深紫外波段的应用前景。.该晶体的成功研制，将丰富非线性光学材料设计与合成的理论体系，有助于推动全固态紫外激光器向实用化、产业化方向发展。

按计划完成了研究内容，实现了预期目标，获得了预期成果。.(a)完成的主要工作是对前期获得了适用于短波紫外非线性光学应用的CBBO晶体进行大尺寸晶体的生长，通过助熔剂体系及生长技术进行深入研究，从而找到合适的晶体生长工艺条件，获得了大尺寸CBBO单晶，并加工光学器件，对其光学性能进行了系统研究，分析晶体结构对晶体线性和非线性光学性能的影响，揭示功能基元与线性和非线性光学性能之间的关系，并对其在266 nm及更短波长的应用前景进行了评估。.(b)通过对碱金属\碱土金属硼酸盐等体系的系统分析发现了十余种具有深紫外截止边的新化合物，NaCa5BO3(SiO4)2 (Inorg. Chem. 2019, 58, 3937), RbSi10O23 和Cs6Si10O23 (Chem. Mater. 2022, 34, 2429), KCa4(BO3)3 和 K0.59 Rb0.41Ca4(BO3)3 (New J. Chem. 2019, 43, 9354), Ba2B7O12F (Inorg. Chem. Front. 2021, 8, 339), NaBa3Si2O7F (Sci. China. Mater. 2019, 62, 1454), Rb5Ba2(B10O17)2(BO2) (Sci. China. Chem. 65, 719), Ba10LuB18O32F13 (Inorg. Chem. Front., 2022, 9, 2298), Li6.58Na7.43Sr4(B9O18)(B12O24)Cl (Inorg. Chem. Front. 2022, 9, 4614-4623), CsB7O10(OH)2 和CsBaB7O12 (Dalton Trans. 2020, 49, 1292)。.(c)基于获得的一系列晶体结构，通过探讨功能基团与非线性光学性能的关系，揭示金属阳离子与硼氧基团对非线性光学晶体材料光学性能的作用，对探索紫外非线性光学材料具有指导意义。.在国际学术刊物发表论文14篇，培养硕士研究生5名、博士生1名。