新型氟碳酸盐深紫外非线性光学晶体材料研究

Deep ultraviolet semiconductor solid-state lasers have important applications in lithography technology, laser spectroscopy, photoelectron spectroscopy, biophysics, laser medicine, etc. Because of the lack of practical deep ultraviolet double frequency crystals, searching for new deep ultraviolet double frequency crystals with high NLO coefficients and wide UV transparency has been one of the main topics in nonlinear optical crystal. Based on the previous work of the deep-UV nonlinear optical borate crystals which have been done by other researchers, [CO3]2- anionic group has been chosen as the basic structural unit for searching for new deep-UV nonlinear optical crystal innovatively in this project. Fluoride atoms have been introduced into carbonates in order to form new compounds with low melting point and wide UV transparency, to expand fluorine carbon oxygen group classification,to summary the law about spatial connection of fluorine carbon oxygen groups and nonlinear coefficient,and to provide more novel crystal structures for deep-UV nonlinear optical materials and screen out potential deep-UV double frequency crystals.

深紫外全固态激光器在半导体光刻技术、激光光谱学、生物物理、光电子能谱、激光医学等方面有重要的应用。由于实用深紫外倍频晶体的缺乏，探索具有大的非线性系数和宽的透过波段的新型深紫外倍频晶体是目前非线性光学晶体研究急待突破的难点之一。本项目在前人深紫外硼酸盐非线性光学晶体研究的基础上，创新性地提出以[CO3]平面三角形基团为基本结构单元，引入电负性最强的氟离子形成具有低熔点和宽透过波段的阴离子复盐的思路，探索合成新型氟碳酸盐化合物，拓展和丰富氟碳氧基团构型,分类总结氟碳氧基团的空间连接与非线性系数大小的规律，为深紫外非线性光学晶体提供结构素材和筛选出有潜力的深紫外倍频晶体。

随着激光科学与技术的不断发展,在频率转换方面,无机非线性光学晶体材料起着越来越重要的作用,特别是在紫外和深紫外光谱区域。设计合成具有大的非线性效应和宽的透过波段的新型无机非线性光学材料是当前的一个具有挑战性的课题。本项目在前人深紫外硼酸盐非线性光学晶体研究的基础上，创新性地提出以[CO3]平面三角形基团作为设计合成新材料的基本结构单元，引入电负性最强的氟离子从而形成具有低熔点和宽透过波段的阴离子复盐的思路，进而探索合成新型氟碳酸盐化合物。通过高温固态法，低温水热法，高温高压水热法合成出来10例氟碳酸盐晶体，并将体系拓展到具有无机平面三角形基团的硼酸盐和硝酸盐中并合成出新型的紫外无机非线性光学晶体材料。通过各种性能测试，筛选出具有潜在应用价值的晶体KSrCO3F,进行大单晶初步生长。本项目极大地拓展和丰富了氟碳氧基团构型，并分类总结氟碳氧基团的空间连接与非线性系数大小的规律，为后续深紫外非线性光学晶体探索合成与生长提供指导。