纳米孔径近场光学显微成像的数值分析

将纳米级光孔的近场分布表征为横电与横磁模式按空间频谱分布的展开叠加,其频谱系数由界面上的电磁分布来确定。在柱坐标系上,横电及横磁各分量的具体形式来源于矢量亥姆霍兹方程的一般解,通过界面上电磁分布的修正,是到更为精确的矢量解,既保留了近场的发散特性,又满足了远场的偶极子分布特性。

Numerical calculation for the near-field optical microscopy with the nanometer aperture

The optical field generated by a nanometer optical aperture can be described as a spatial frequency expansion over a complete set of the transverse magnetic and transverse electric field modes. The expansion coefficients are defined by the electromagnetic field in the boundary plane. In cylindrical coordinates, the transverse magnetic and transverse electric field modes are from the general solutions to the vector|wave equation (Helmholtz equation). By modification of the electromagnetic field expressions in the boundary plane, the vectoral solution preserves the divergent behavior of the near|field and the dipolar nature of the far field. This formalism is simply described as a one|dimensional Fourier integral. And it can be directly applied to the near|field simulation of the nanometer laser knife.