用数值方法分析微孔激光器出射光的近场特性

微孔激光器作为应用于近场光信息存储系统中的一种新型光源，它的出射光斑的近场特性对于近场光存储是十分重要的。针对纳米孔径运用角谱进行Fox-Li数值迭代，得到不同孔径微孔激光器的基模光强分布，然后运用二维非线性时域有限差分法分析微孔激光器出射端即微孔金属膜的近场光学性质，模拟计算了不同孔径和厚度的微孔金属膜的光强近场分布，从应用于近场光存储的角度，给出反映其近场光学特性的相关数据。发现由于TM模式下金属存在局域表面等离子增强效应，使得其出射强度比TE模式高一个数量级，从而更适于作为实际中近场光存储系统和原理试验的光学头。

Numerical Analysis of Micro-Aperture Laser for Near Field Optical Data Storage

The very small aperture laser(VSAL) is an important light source used in the near-field optical storage system. The near-field property of VSAL′s output light is studied. The optical characteristics and the intensity distribution in the near-field of the output region,that is, micro-aperture metallic film, of the VSAL have been numerically simulated by using two-dimensional nonlinear finite difference time domain(2D-NL-FDTD) method and the Fox-Li method with angle spectrum. Through analyzing the results from the viewpoint of the optics, the possible application in the near-field optical recording have been discussed, and some curves indicating the near-field optical charactersistics of the output light have been presented. It is found that because of the localized surface plasmon ehnancement for the TM mode, the output of TM mode is about ten times stronger than the one of TE mode and more suitable for being used in the near-field optical storage system.