利用平行處理之時域有限差分法探討銀奈米結構菲涅耳波帶片之聚焦性質

Abstract

本論文分析並模擬具有銀奈米薄膜的菲涅耳波帶片，藉由表面電漿效應及光學繞射行為對光場在聚焦平面上做重建。銀奈米結構的菲涅耳波帶片，其特殊的幾何外型，證實在特定的聚焦平面有光場聚焦特性，並可以應用在奈米微影上。 基於時域有限差分法我們在銀奈米結構的菲涅耳波帶片中研究其聚焦行為，並使用叢集式電腦及訊息溝通介面(message passing interface，MPI)函式庫將序列程式平行化，目的在解決大範圍或複雜結構之電磁場的問題，藉由多處裡器的運算，將大幅增加可使用之記憶體，並能降低運算的時間。

The light intensity rebuilt in the focal plane by Fresnel zone plates in silver films can be described by the plasmonic effects and optical diffraction. We find that the silver Fresnel zone plates with specific geometry can reconstruct the light distribution, and they have the great potential for nanolithography application. Based on the finite-difference time-domain method, we can study the focus properties of silver-nanostructure Fresnel zone plates. The simulation results show that the light enhancement varies with structures. We use message passing interface library to parallelize our in-house developed finite-difference time-domain software package, which can access more processors and memories by clusters.