Department of Physics and Center for Optical Technologies, Lehigh University, Bethlehem, PA 18015, USA.
J Phys Condens Matter. 2010 Apr 28;22(16):165903. doi: 10.1088/0953-8984/22/16/165903. Epub 2010 Apr 6.
We discuss the potential functionalities of a mixed tellurite-chalcogenide glass where alternate oxygen atoms in a TeO(2) vitreous network are substituted with either sulfur or selenium atoms. We calculate the microscopic linear and nonlinear polarizabilities of chains with a finite number (n) of TeOX (X = S or Se) units from ab initio quantum chemistry computations and apply rotational averaging to the results. We find that the rotationally averaged linear polarizability, α(av), increases linearly with the number of units, while the second hyper-polarizability, γ(av), grows as a power law with an exponent that changes from 1.2 to 1.9 and 2.4 when going from pure tellurite to S substitution and Se substitution, respectively. We then estimate the density of the resulting glass and local field corrections to obtain the macroscopic linear and nonlinear susceptibilities for a glass made from chains of n = 5. We find that the extra Te-S (or Te-Se) bonds in the mixed tellurite-chalcogenide system enhance the linear refractive index n(0) and the third-order susceptibility χ((3)) by factors of ∼ 1.3 (or 1.4) and ∼ 8 (or 14), respectively, over the base tellurite glasses (X = O).
我们讨论了一种碲酸盐-硫属化物混合玻璃的潜在功能，其中 TeO(2) 玻璃网络中的交替氧原子被硫或硒原子取代。我们通过从头算量子化学计算，计算了具有有限数量(n)的 TeOX(X = S 或 Se)单元的链的微观线性和非线性极化率，并对结果进行了旋转平均。我们发现，旋转平均线性极化率 α(av) 随单元数量线性增加，而二次超极化率 γ(av) 则以幂律增长，当从纯碲酸盐到 S 取代和 Se 取代时，指数从 1.2 变为 1.9 和 2.4。然后，我们估计了玻璃的密度和局部场修正，以获得由 n = 5 个链组成的玻璃的宏观线性和非线性磁化率。我们发现，混合碲酸盐-硫属化物系统中的额外 Te-S(或 Te-Se)键使线性折射率 n(0)和三阶磁化率 χ((3))分别增加了约 1.3(或 1.4)和约 8(或 14)倍，超过了基本的碲酸盐玻璃(X = O)。
