混合光子晶体等离子激元纳米微腔

Hybrid Plasmonic Photonic Crystal Nano Micro-Cavity

构建了一种三层混合光子晶体等离子体激元结构,分别为金属银(Ag)层,低折射率二氧化硅(SiO2)层和二维光子晶体层。这种混合光子晶体等离子体激元结构具有明显的横磁模(TM)模式带隙。在二维的光子晶体层的中心引入一个单元胞缺陷,形成缺陷腔结构。这种纳米尺度的光子晶体等离子体微腔的体积远小于传统介质的光学微腔,光子能量可以很好地被局域到低折射率层,实现了深亚波长尺度下的对光的限制。通过改变该混合光子晶体等离子激元结构的参数,利用三维时域有限差分(3D-FDTD)方法,分析了这种混合光子晶体等离子微腔结构的光学特性。分析表明:这种纳米微腔具有极小的模式体积0.0141(λ/n)3和高的Q/V值。

A kind of three-tier hybrid plasmonic photonic crystal which is respectively constituted by a metal layer of silver（Ag）,a low refractive index dielectric layer of SiO2 and a two-dimensional photonic crystal layer,is proposed.A clear plasmonic transverse-magnetic（TM）bandgap can be formed in this hybrid plasmonic photonic crystal.The defect cavity is constituted by introducing a unit cell defect in the center of the two-dimensional photonic crystal layer.The volume of the hybrid plasmonic photonic crystal micro-cavity is based on nano-scale,which is much less than the conventional optical micro-cavity,and the photon energy is well confined in the low index layer,so light can be limited at deep sub-wavelength scale.With some different structure parameters,the numerical analysis method of threedimensional finite difference time domain（3D-FDTD）is used to analyze the characteristics of this hybrid plasmonic photonic crystal.The analysis indicated that this kind of nano micro-cavity has an ultra-small mode volume of 0.0141（λ/n）3 and an ultra-high Q/V.