中紅外二元式Fresnel透鏡微小光學元件的設計與製作

Abstract

本論文研究主要目的係針對IRCCD為增加Gamma幅射強度及為減小雜訊干 擾所作之減小偵測器的偵測面積,在不失其解析度的情況下,於物鏡與焦平 面陣列間插入一微型透鏡陣列,以提高有效偵測面積的透光率,繼而提昇光 學系統的光學效率. 二元式Fresnel微型透鏡是利用光的繞射現象來達到 聚焦的目的,故本論文研究的主要方法將以"傅利葉光學"作為分析二元式 Fresnel微型透鏡的數學方法,並採用純量繞射理論近似法來計算,分析透 鏡的各種性質. 論文中述及二元式Fresnel微型透鏡的光學原理,光學模 擬,透鏡設計,透鏡製作,透鏡效能量測及分析因製程誤差所導致的光學效 率的降低及二元式Fresnel微型透鏡的未來發展及限制.本論文共製作了兩 組二元式Fresnel微型透鏡,其中一組針對IRCCD來設計,此組僅做定性分 析;另一組則為了方便量測而製作,由此組透鏡的定量分析可得知二元式 Fresnel微型透鏡應用在中紅外波段應可發揮其光學功能. The objective of this thesis is to reduce noise result from the decrease in photo-detector surface area by inserting a microlens array between objective lensand focal plane array.By doing so, optical fill factor and the optical efficiencycan be greatly increased.In this thesis,we present design objective,simulation, design rules,fabricationprocess,measurement,analyses of the discrepancies of optical efficiency resultedfrom fabrication processes.We fabricated two sets of Binary Fresnel Microlens on 6 inch Si wafer.One set isdesigned and fabricated according to IRCCD specification.This set of lens is analyzed qualitatively. The other is fabricated to faciliate the device testingboth quantitatively and qualitatively.Through these measurement and analyses,weconclude that the Binary Fresnel Microlens is applicable for mid-infrared wave-band applications.