Numerical analysis for lacarized and ehnhaneed surface plasmon polariton of near field of dumbbell-Shaped aperture in the metallic screen.

金属屏哑铃形孔径近场泪化和增强表面等离子体激元的数值分析

基本信息

批准号：
15560030
负责人：
TANAKA Kazuo
金额：
$ 2.24万
依托单位：
Gifu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

The characteristics of optical near-fields around subwavelength apertures in metallic screens are important in research on near-field optical (NFO) technology. The aperture-scanning near-field optical microscope (aperture SNOM) is the most notable application of this technology, and offers resolution approximately equivalent to the dimensions of the subwavelength aperture. The aperture in these applications is smaller than the cutoff radius of the modes propagating in the probe, with the result that all modes run into cutoff and the aperture emits only an extremely small fraction of the input power. The aperture diameter cannot be reduced arbitrarily because a minimum level of emission must be ensured. Low transmission, observed as low light intensity at the aperture, therefore becomes the primary factor limiting the resolution of aperture SNOM. Optimization of the optical probe is therefore of great importance for advancement of the SNOM technique.Increasing the near-field intensity o … More f a subwavelength aperture has thus far been considered to be a trade off with smaller spot size. However, the present authors have recently proposed an I-shaped (dumbbell-shaped) aperture in a metallic screen that provides both high emission intensity and small spot size simultaneously, and have shown that this interesting characteristic is due to the surface plasmon polariton (SPP) excited inside the aperture.In this project, the dependence of the near-field intensities of the I-shaped aperture in a thick metallic screen on various parameters are investigated in detail, and the design of the I-shaped aperture is optimized so as to obtain high near-field intensity and small spot size. The scattering of optical waves scattered by the I-shaped aperture is solved numerically and the near-field intensities and scattering cross-sections of the aperture are calculated. The solutions are obtained numerically using a volume integral equation (VIE) by generalized conjugate residual (CGR) iteration and fast Fourier transformation (FTT). Less

金属屏幕中亚波长周围光圈周围光学近场的特征在近场光学（NFO）技术的研究中很重要。孔扫描近场光学显微镜（Aperture SNOM）是该技术最著名的应用，并且提供了与亚波长孔径的尺寸大致相等的分辨率。这些应用中的孔径小于探针中传播模式的截止半径，结果所有模式都符合截止，并且光圈仅发出了非常小的输入功率。由于必须确保最低的发射水平，因此无法降低光圈直径。低透射率（视为孔径处的低光强度），因此成为限制孔径分辨率的主要因素。因此，光学探针的优化对于提高SNOM技术至关重要。介绍近场强度o…迄今为止，更多的次波长孔被认为是较小的点大小的交易。然而，目前的作者最近在金属屏幕中提出了一个I形的（哑铃形）孔，可以非常简单地提供高发射强度和小的斑点尺寸，并且表明，这种有趣的特征是由于表面等离子体极性（SPP）造成的，这是由于在该项目中兴奋的型号。 I形光圈的设计进行了优化，以获得高近场强度和较小的斑点尺寸。单独求解由I形孔径散射的光波的散射，并计算了光圈的近场强度和散射横截面。通过广泛的共轭残差（CGR）迭代和快速傅立叶变换（FTT），使用体积积分方程（VIE）单独获得溶液。较少的