無移動結構之可調變固態微型光圈

Abstract

本研究提出一個創新概念來製作無移動結構之固態式微型可變光圈。光圈的大小可以經由施加不同的電壓來調變。在微型可變光圈的調變機制的設計中，分散型液晶(Polymer Dispersed Liquid Crystal, PDLC)薄膜扮演了很重要的角色，藉由結合特殊的微米圓頂型結構與分散型液晶能夠作為光開關的特性，可使得光圈薄膜結構中距離圓頂頂部中心徑向方向越遠的之處相較於較近部分有較大的臨界電壓，因此當作用電壓逐漸上升，中央部分臨界電壓較低的部分即會先行透光，光圈開孔大小便隨著電壓的上調升而越大。在本研究中對於圓頂結構的製作，提出兩種不同的方法，分別是熱整流製程（Thermal reflow process）以及使用奈米顯微注射器注射(Micromanipulators)高分子的方式，本文中透過測量實驗，可以求得通過光圈的光束於相機成像面的束寬對於應用電壓的關係，並進一步討論與比較兩種圓頂結構元件的效能以及兩者對應的不同製程參數所造成的影響。

This thesis proposes the design, fabrication and measurement experiment of an innovative solid-state variable micro aperture. This variable aperture can be modulated by applied voltage and it doesn't require any moving components. PDLC (polymer dispersed liquid crystal) is a critical element in its tunability. By combing a micro dome structure and the PDLC, electrically-modulated aperture variation can be completed. Also, two different methods are applied in producing micro dome structure, including photolithography process combined with Thermal reflow process and the other one forming NOA65 polymer dome by micromanipulators. In this thesis, both methods are covered and discussed. In measurement experiment, aperture variation is observed and analyzed with imaging processing of acquired photos from both devices. Eventually, an important property of this electrically-modulated aperture, the relation between beam sizes on image plane of input light and applied voltage, is obtained. Last but not the least, we also focus on the pros and cons of these two kinds of devices, in order to develop a better solution.