非线性光学晶体三硼酸铋的拉曼光散射

Raman spectra of a nonlinear optical crystal:bimuth triborate

结构分析表明非线性光学晶体三硼酸铋BiB3 O6的晶胞参数为a1=0 .7116nm ,a2 =0 .4993nm ,a3 =0 .65 0 8nm ,β =10 5 .62° ,每个初基晶胞含有二个分子。在不同几何配置下的激光拉曼光谱观察到了晶体中硼氧四面体和硼氧三角形的特征晶格振动和振动模的分裂。拉曼光谱表明晶体的内部结构有很强的各向异性 。

The lattice parameters of nonlinear optical crystal bismuth borate were a 1=0.7116nm, a 2=0.4993nm, a 3=0.6508nm, β =105.62° from the structure analysis. There were two molecules in preliminary cell. From the Raman spectra of different arrangement we have observed the lattice vibration of boron oxygen tetrahedral and boron oxygen triangle. Raman spectra show that there were strong antiisotropy in the structure, that′s the oringin of the nonlinear optical properties of the crystal.