深刻蚀光栅的偏振效应研究

项目名称： 深刻蚀光栅的偏振效应研究

项目编号： No.60878035

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 周常河

作者单位： 中国科学院上海光学精密机械研究所

项目金额： 39万元

中文摘要： 深刻蚀光栅就是指光栅周期在波长量级，刻蚀深度达到特定优化值的光栅，由此可以实现偏振分光新效应，有重要应用前景。偏振分光器是基础光学元件，应用极其广泛。 本项目研究的亚波长光栅只有0 级和－1 级光，通过表面矩形浮雕刻蚀深度的优化（深刻蚀），偏振光分别出现在－1 级或者0 级，具有高的效率(>90%)和隔离度（消光比>100:1）。石英是非常优良光学材料，热膨胀系数小，从紫外到红外均有很好的光谱透过率。本项目采用Botten 模式方法对深刻蚀亚波长石英光栅进行了深入研究，进一步发现在整个光通信的(C+L)波段具有宽带的偏振分光特性，原因在于激发的两个模式折射率差近似为一个常数。本项目将深入研究深刻蚀光栅的丰富偏振特性，使之出现类似于晶体的偏振分光功能，并具有宽带特性，因此，本项目的研究既有重要的科学意义，也有重要的应用前景。

中文关键词： 光栅；深刻蚀光栅；石英光栅；偏振分束；衍射模式理论

英文摘要： Deep-etched grating means its period in the wavelength scale and its groove in the optimized deep-etched depth, so that it can function as a novel polarization beam splitting element for practical applications. Polarization beam splitter is one basic optical element which has wide applications. This project will study the subwavelength grating which has only the zeroth and minusone orders, with the optimized rectangular surface-relief depth(deep-etched), polarization separated beams will appear in the minus-one and zeroth orders, respectively. Fused silica is an excellant optical material with slight thermal expension and wide spectrum transmission from the ultravielot to the infrared. This project will use the Botten's modal method for analysis of deep-etched subwavelength fused silica grating, in order to show its capability of the wide polarization separation over the entire optical communication C+L band, which is due to the approximate contant of the phase difference between the excited modals' effective index. This project will study the rich characteristics of its capability for polarization separation as a crystal, and more important, it can work over a wide sepectrum. Therefore, this project has the significant scientific meaning, together with important practical applications in the near future.

英文关键词： grating;deep-etched grating;fused silicagrating; polarization separation; modal theory