有限尺寸的陣列對於次波長孔徑陣列穿透率增強現象之影響

Abstract

本篇論文主要的目的是研究次波長孔徑的微波穿透率，設計分析孔徑的大小與陣列的排列並且進行實驗，實驗的波段在8 GHz到12 GHz，在單一孔徑的實驗當中，我們量測了次波長孔徑的穿透量並且跟Bethe’s limit來比較，另外也研究了孔徑的形狀與微波穿透率的相關性。在多孔徑陣列的實驗中，我們研究了有限尺寸的陣列對於穿透率增強現象的影響，主要使用的是最基本的3X3-array。本論文驗證了由於表面電漿被激發而產生的穿透量增強現象，並且發現在滿足表面電漿被激發的條件時，穿透量因為光束束寬和陣列面積的影響具有多值現象。

We experimentally investigate the transmission characteristics of subwavelength aperture by microwave analog experiment (8GHz ~ 12GHz), paying attention on enhancement feature. We found that in single hole cases, the transmissions depend on the shape of the apertures. For multiple hole cases, we investigate the influence of finite-size effect on the transmission characteristics of multiple subwavelength apertures. Within a finite size of confirmed area, a basic unit element of multiple apertures (hole array), i.e., a 3X3 array, is considered. We observed astonishingly transmission maximum and verify that the results indeed correspond to the excitation of surface plasmons. It is found that the transmission versus the ratio between the wavelength and the aperture size ( ) can be multi-valued when surface plasmons are excited.