中文摘要：

设计了一种基于非线性介质Si-NC/SiO2的混合表面等离子体波导,利用有限元方法定量分析了这种波导所支持基模的能流密度分布、有效折射率、传播长度和有效面积与几何结构参数以及非线性介质的依赖关系.分析结果表明,光场主要被限制在非线性区域,通过调节非线性层的厚度以及非线性比例因子,可以实现模式的有效折射率和传播长度等传输特性参数的调节.固定非线性介质比例因子,有效折射率和传播距离随非线性层厚度增加而增大;固定波导尺寸,有效折射率随比例因子增大而增大,传播距离和有效面积较小.最后,根据分析结果对非线性效应进行优化,优化后波导最优结构尺寸为波导宽度为250nm,非线性材料层厚度为100nm,硅层厚度为150nm.

英文摘要：

A kind of hybrid surface plasmonic waveguide based on the nonlinear media of Si-NC/SiO2 was designed.The dependence of the distribution of longitudinal energy flux density,the effective refractive index,the propagation length and the effective area of the fundamental mode of the waveguide,on the geometrical parameters and the nonlinear volume fraction were analyzed by the finite element method.Simulated results reveal that light field is distributed mainly in the nonlinear material.The transmission parameters of the fundamental mode,such as the effective index and propagation length can be adjusted by tuning the size and the volume fraction of nonlinear material.When the volume fraction is given,the effective index and propagation length will increase as the thickness of the nonlinear material increasing.With a certain geometric parameter,the effective index will increase as the volume fraction increasing,the propagation length and the effective area will decrease.Finally,the nonlinear effect was optimized according to the analysis results,and the optimized structure size is given by that,the width of waveguide is 250 nm,the thickness of the nonlinear material layer and silicon layer is 100 nm and 150 nm respectively.