手徵型光子晶体光学二极体的分析与应用Analysisand-先进工程学刊.PDF

先進工程學刊第四卷 第四期 319 Journal of Advanced Engineering Vol. 4, No. 4, pp. 319-324 / October 2009 手徵型光子晶體光學二極體的分析與應用 Analysis and Application of Optical Diodes Using Chiral Photonic Crystals *1 2 3 4 陳俊宇 葉佳益 林金田張智傑 *1 2 3 4 Jiun-Yeu Chen , Jia-Yi Yeh , Chin-Tien Lin , Chih-Chieh Chang 摘要 以光子晶體的能帶隙概念，選擇具螺旋結構之膽固醇液晶作為探討對象。此 薄膜在頻譜特性上會顯現選擇性光散射，可用來設計一種特性猶如電子二極體的 光學元件，使特定波長的光能在一個方向上通過，但在反方向上卻無法通過。本 文由 兩個模型來說明，並以數值模擬來驗證。最後以當作色彩分離器為例 ，討論 將其整合到光機電系統時，可作為色彩分離機構使用。 關鍵詞 ：光子能帶隙，光子晶體，光學二極體，膽固醇液晶 ，色彩分離 Abstract In the article, the concept of photonic band-gaps (PBGs) is used to design a novel optical component. Among many substances having PBG structures, cholesteric liquid crystals (ChLCs) with periodic helical structures are chosen to discuss their applications. The selective reflection in the spectral properties of ChLC thin films can be used to design an optical device that permits the propagation of a band of wavelengths in one direction and blocks it in the other, acting as an optical diode (OD) analogous to an electric diode. In the research, two models are proposed to demonstrate the diode behavior and are verified by the numerical simulations. Finally, two examples to