S取代Se对Ge_(11.5)As_(24)Se_(64.5-x)S_(x)玻璃结构及光学性质的影响

Effect of substitution of S for Se on structure and physical properties in Ge_(11.5)As_(24)Se_(64.5-x)S_(x) glass

本文制备了硫系玻璃Ge_(11.5)As_(24)Se_(64.5-x)S_(x)(x=0,16.125%,32.25%,48.375%和64.5%)并研究了其光学性质,目的在于筛选可用于光学器件的最佳组分.通过测试该系列玻璃的激光损伤阈值、折射率、三阶非线性折射率以及吸收光谱,结果发现,玻璃中的Se被S原子逐渐替代后,玻璃的线性和三阶非线性折射率逐渐降低,玻璃光学带隙和激光损伤阈值不断升高.我们进一步利用拉曼散射光谱和高分辨率X射线光电子能谱研究导致这些物理性能变化的结构起源,通过分析玻璃中不同结构单元的演变过程,发现在这些玻璃网络结构中均以异极键(Ge—Se/S,As—Se/S)为主,且相对于Se而言,Ge和As优先与S结合成键.随着玻璃结构中S/Se比例的增加,与Se相关的化学键(Ge—Se,As—Se和Se—Se)数量逐渐减少,S相关化学键(Ge—S,As—S和S—S)数量逐渐增加,但这对玻璃的拓扑结构几乎没有影响.由此可以断定引起玻璃物理性质变化的主要原因是玻璃结构体系中各个化学键强度之间的差异.

In this paper,chalcogenide glasses Ge_(11.5)As_(24)Se_(64.5-x)S_(x)(x=0,16.125%,32.25%,48.375%and 64.5%)are prepared and their optical properties are studied in order to select the best components for the use in optical devices.The values of laser damage threshold,refractive index,and third-order nonlinear refractive index,as well as the absorption spectra of the glasses are measured.The results show that the linear and third-order nonlinear refractive indices of the glass decrease gradually,the glass optical band gap increases gradually,and the laser damage threshold increases continuously after the high threshold component S atoms have been introduced gradually.We further investigate the structural origins of these changes in physical properties by Raman scattering spectra and high resolution X-ray photoelectron spectroscopy.By analyzing the evolution process of different structural units in the glass,it is found that the heteropolar bonds(Ge—Se/S,As—Se/S)are dominant in these glass network structures,and compared with Se,and that Ge and As prefer to bond with S.As the ratio of S/Se increases,the number of chemical bonds related to Se(Ge—Se,As—Se and Se—Se)decreases gradually,while the number of chemical bonds related to Se(Ge—S,As—S and S—S)increases gradually,which has little effect on the change of the topological structure of glass.It can be concluded that the main reason for the change of physical properties of glass is the difference of the strength between chemical bonds in the glass structural system.