【摘要】 研究了低重复频率飞秒激光在石英玻璃内部诱导的自组织纳米条纹与激光参数和扫描参数的关系,发现激光扫描轨迹横截面纳米光栅的填充因子随扫描参数而变化。在一定的写入窗口,纳米光栅具有偏振依赖导光特性,属于II类波导;实验研究了六边形结构II类波导的导光特性,与重复频率为100kHz的飞秒激光光刻波导规律具有相似性;理论上构建了II类波导和六边形结构横截面折射率轮廓的理想模型,利用有限元方法分析了II类波导及六边形结构的模式,并从实验上和理论上说明了II类波导的偏振依赖导光性不是由于纳米光栅的形序双折射,而是由于纳米光栅的偏振依赖散射。更多还原

【Abstract】 The dependences of self-assembled nanograting in fused silica on low repetition frequency femtosecond laser parameters and scanning parameters are investigated.The results show that the filling factor of nanograting for scanning path cross section depends on the writing parameters.The type II waveguide in fused silica can be written under some writing condition and shows polarization-dependent guiding properties.Similar polarization-dependent guiding properties with 100 kHz situation is proved in experiment by hexagonal structures assembled from type II traces.Ideal models of the cross-sectional refractive index profiles of type II waveguides and the hexagonal structures are constructed.Corresponding modes are simulated using the finite element analysis method.It is found that the polarization-dependent optical guiding properties of type II waveguides are due to polarization-dependent scattering of nanograting rather than form birefringence in theory and experiment.更多还原