使用單一繞射元件製作全光調控二維光柵之研究

Optically tunable two-dimensional holographic gratings fabricated using a single diffractive element

李錫閎(Shi-Hung Lee)

指導教授 ： 蕭桂森

國立暨南國際大學/科技學院/光電科技碩士學位學程/碩士(2012年)

https://doi.org/10.6837/NCNU.2012.00221

摘要

在本論文中我們將探討利用高分子與向列型液晶結合並參雜偶氮苯分子製作成液晶聚合物, 再利用單一繞射元件使一道514nm波長的氬離子雷射光通過, 產生二維六角形的光強弱分布, 製作出可全光調控的液晶聚合物光柵, 其繞射波段可光控位移約25nm, 並使用偏光光學顯微鏡觀察光柵之週期結構, 驗証我們所製造出來的H-DPLC光柵週期與理論模擬圖是在合理範圍之內。
另外當我們使用405nm 二極體雷射打在光柵上時，明顯的發現不論是P偏振光或S偏振光其穿透效率明顯的下降了，而繞射效率變好，當移除405nm 二極體雷射後，穿透與繞射效率逐漸回復為初始值，反覆數次驗證我們所製作的二維全光調控H-PDLC光柵有良好的調控的效率與偏振特性, 也期望本研究結果將來可以實際應用於市面上的液晶光學元件上。

關鍵字

全光調控 ； 偏振 ； 液晶聚合物光柵 ； 全像術

並列摘要

In the paper, we will discuss the azo dye-doped nematic liquid crystal to make the liquid crystal polymer. Using the unit diffraction element to guide the wave length of 514 nm laser light to go through, and create two-dimension hexangular light. By this way we can produce full light adjustment of polymer with optical grating. The wave of diffraction can shift 25 nm of optical control and we can use optic microscope to observe the construction of optical grating .Then we testify the reasonable range of H-DPLC we make.
In the other hand, when we use 405 nm diode laser to shoot on the optical grating, we can easily find the transmission rate to go down trend, no mater it’s on P polarized light or S polarized light. But on the contrary, the ratio of diffraction get better. We take out the 405nm diode laser, the ratio of transmission and diffraction go back the initial value.After repeating the working for several times to prove the two-dimension H-DPLC we make and it really has good control on the adjustment and polarization. I expect the research can utilize on the liquid crystal element in the future.

並列關鍵字

optically switchable ； polarization ； H-DPLC grating ； holographic

參考文獻

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