二维金属波导阵列的亚波长自聚焦效应

利用时域有限差分（FDTD）方法对不同入射波长和不同结构参量的Ag波导阵列自聚焦现象进行了数值分析.分析表明：焦点位置与光源到Ag波导阵列的距离s,Ag波导阵列入射面形状以及入射波长有关.随着光源到Ag波导阵列距离s的增大,焦点位置逐渐变远;随着入射面凹陷步长b减小,焦点位置逐渐变远;随着入射面凹陷深度d的增大,焦点位置逐渐变远.入射面的形状可以较大程度影响焦点位置以及焦点处的光强.当Ag波导阵列的结构一定时,自聚焦的焦点位置均与入射波长成线性关系.结果表明,可以通过适当地调节参数得到理想的焦点位置.

Study of Subwavelength Self-Focus Effect in Two-Dimensional Ag-waveguide Arrays

ubwavelength self-focus effect in a set of nanoscale Ag-waveguide arrays(Ag-WGAs) is numerically simulated with the finite-difference time-domain(FDTD) method.The result shows that the self-focus behavior can be modulated significantly by tuning the distance between the light source and the input facet of the Ag-WGAs,the surface configuration of Ag-WGAs and the wavelength of the incident wave.The surface configuration of the waveguide arrays has enormous effects on the focal distance and the corresponding i...