有機可形變面鏡應用於適應性光學

Abstract

中文摘要 可形變面鏡用於天文觀測上已行之有年，近年來在生物醫學、光衰減器、微型成像系統的應用上有不少的突破。在本篇論文中，我將探討有機光學薄膜製程上所遭遇到的問題及其解決方法。另外我們提出微型有機薄膜架構的設計，此設計改良了一般有機薄膜在製作上的精準度問題，並進一步解決了有機薄膜可形變面鏡晶片的封裝問題。 我們選擇了低殘餘應力的有機材料，使用微機電製程製造出一微米厚度的有機薄膜，並在此薄膜上使用黃光製程定義出我們所需要的開孔形狀。由於製程的改進，我們已經可以將薄膜的殘餘應力和楊氏係數降低至 2.5 MPa 與 10 GPa。以此優秀的機械性質，我們在可形變面鏡最重要的位移實驗中達到了四十微米的位移並指施加了兩百五十伏特的電壓。此外，我並使用了反射式光偵測器對於可形變薄膜所反射的雷射做分析，由此我可以量測出薄膜所達到的形變曲率。在有機可形變薄膜的光學品質改良上，我們在製程中盡量使用低溫的製程步驟，因此我們在微型可形變面鏡表面粗操度上可達到小於二十分之一可見光波長，這對於光學成像系統的應用幫助非常的大。 綜合以上的結果，我們已經成功的設計、製造並量測我們製造的有機可形變薄膜。希望以此薄膜優秀的機械特性，將來能應用於更多方面的科學研究，對於科技的發展有些許的幫助。

Abstract It is popular that scientist using deformable mirror in astronomy observation for a long time, and deformable mirror’s application in biomedical application, VOA, and optical image system is gradually developing in recent years. In the thesis, I discuss about the obstacles we met when designing or fabricating an optical deformable mirror. Besides, we present a new model of deformable mirroe, and it improved the accuracy problem when defining the shape of the mirror, and the package problem of the mirror. Here we choose a low stress polymer material as the membrane structure. By MEMs technology, we produce the thin film with only 1 (um) thickness, and we define any desired shape on thin film by lithography. Owning to the progress of process, we can further lower down the residual stress and young’s modulus to 2.5 MPa and 10 GPa. By the excellent mechanical properties, we achieve almost 40 um deflection in less than 250 Volts applying voltage. Moreover, we use the reflective beam profiler for analyzing the reflected laser beam, we can measure the curvature of the mirror from this data. In the image quality purpose, we try to use the low-temperature process in the process flow. From this we can achieve surface roughness less than 1/20，visible light wavelength which is helpful for the optical image system. We have successfully designed, fabricated and tested the deformable mirror, and from the excellent mechanical properties of the mirror, it is believed that the applications can be developed and widen, and have some assistance for human technology.