硅树脂材料热光特性的测试与分析

用激光-V棱镜装置测得耐热型硅树脂在632.8nm和650nm波长上的热光系数分别为-3.3×10-4/℃和-3.6×10-4/℃。以石英玻璃为衬底,用该材料制作了平板波导,用棱镜耦合法测量了不同温度下波导的有效折射率,利用平板波导模式本征方程求解出不同温度下导波层的膜厚与折射率,分析了有效折射率随温度变化的特点。根据导波层折射率与厚度的变化和高分子材料的克劳修斯莫索提公式,分析出该材料的极性分子较大,是引起负热光系数大的原因。该材料适合用于研制低功耗、与塑料光纤匹配的短距离光通信热光开关。

The Test and Analysis for Thermo-Optic Effect of Silicon Resin

The calorescence coefficients of silicon resin reached -3.6×10-4 /℃ at 650 nm, and -3.3×0-4 /℃ at 632.8 nm which were tested by V prism device. A silicon resin waveguide is formed on a quartz substrate and its effective refractive indexes N at different temperatures are detected by coupled prism method. The thickness h and refractive index n1 of the film at different temperatures are calculated and these results show that the variety of N comes from the n1 and the reflection angle of guided wave on the boundary. The experimental results of waveguide reveal that the larger calorescence coefficients of silicon resin are induced by the larger orientational polarizability of the molecules in the material and it can be useful in making the thermo-optic switch of low power dissipation in short-range networks.