兼具低非线性和高功率限制的狭缝波导（英文）

利用非线性效应的全矢量模型和狭缝波导的有限元模场求解法,系统地研究了狭缝波导结构和包层材料对其非线性和功率限制特性的影响.研究结果表明,狭缝波导的硅臂宽度、狭缝宽度、硅层高度和包层材料均影响其非线性和功率限制特性.对于空气包层狭缝波导,不同结构参数下的最高功率限制因子对应的非线性系数均高于20 W^-1·m^-1,而最低非线性系数6.5 W^-1·m^-1均出现在模式截止附近,泄露损耗较大,功率限制较弱,故空气包层狭缝波导无法同时实现低非线性和高功率限制;如果在狭缝波导上包覆二氧化硅,则可以同时获得低非线性和高功率限制,非线性系数可低至4.12 W^-1·m^-1,同时功率限制因子可达42%.

Simultaneous Low Nonlinearity and High Power Confinement in Slot Waveguides

The effects of the slot waveguide structure and cladding material on the nonlinearity and the power confinement were systematically investigated by using the full vectorial model of the nonlinear effect and the finite element mode solver of the slot waveguide.The results show that the nonlinearity and the power confinement can be significantly affected by the silicon-arms width,the slot width,the thickness of the silicon layer and the cladding material.For the air-cladding slot waveguides with different structural parameters,the corresponding nonlinear coefficients are all above 20 W^-1·m^-1 for the maximal power confinement factors,and the minimal nonlinear coefficients of 6.5 W^-1·m^-1 are all obtained near the cut-off mode where the slot waveguides suffer from the leakages to the substrate.The low nonlinearity and the high power confinement can not be realized at the same time for the air-cladding slot waveguide.But the low nonlinearity and the high power confinement can be obtained simultaneously if the silica is coated on the slot waveguide,where the nonlinear coefficient can be as low as 4.12 W^-1·m^-1 and the power confinement factor can be as high as 42%.