基于“凸面曝光-凹面复制”法的平场凹面光栅设计与制作关键技术研究

项目名称： 基于“凸面曝光-凹面复制”法的平场凹面光栅设计与制作关键技术研究

项目编号： No.61205167

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 信息四处

项目作者： 周倩

作者单位： 清华大学

项目金额： 29万元

中文摘要： 平场凹面光栅集色散、聚焦、平像场于一体，是光栅光谱仪器中的关键元件。然而受凹面基底几何形状的限制，凹面光栅很难采用离子束直接刻蚀，很多情况下甚至完全不可能，导致凹面光栅的槽型无法精确控制，衍射效率一直难以提高，成为其应用瓶颈。针对这一问题，我们提出直接曝光制作凸面母光栅，然后复制得到平场凹面光栅的方法。由于凸面光栅易于刻蚀，因而该方法为通过离子刻蚀控制凹面光栅槽型提供了一种切实可行的解决方案。用ZEMAX进行的初步仿真结果证实采用本方法与传统直接曝光法制得的凹面光栅像质性能相当。进一步，针对曝光光路中两个点光源由于受到机械结构限制不能过于靠近的问题，我们提出在光路中加入"补偿镜"的方法，拉大实际曝光点的间距，有效避免两路空间滤波器之间的干涉。本项目将对上述方法在优化设计、制作工艺、系统集成中的关键问题进行攻关，探索出一整套可行的解决方案，为未来制作闪耀平场凹面光栅打下坚实基础。

中文关键词： 平场凹面光栅；凸面光栅；全息曝光；光学设计；

英文摘要： A flat-field concave diffraction grating is the key component of a portable grating spectrometer, because it integrates three optical properties: dispersion, imaging, and flat spectral image plane. The diffraction efficiency of a grating depends mainly on its groove shape. The common technology to accurately control the groove shape is to first produce a photoresist grating mask by using the standard holographic technique, and then to perform dry etching by using a collimated ion-beam. However, a uniform blazed angle across the whole grating area cannot be obtained because the incident angle of the ion beam is restricted by the curvature of the concave substrate. This problem, with which the researchers have confronted for a long time, severely limits the diffraction efficiency and restricts the application of concave gratings. We proposed a method to fabricate flat-field concave gratings by replicating a convex master grating fabricated directly by the holographic recording. The method translates etching a concave grating into etching a convex grating, and greatly reduces the difficulty of ion-beam etching. Furthermore, the distance between two light sources in the fabrication light system are often short, which makes it difficult to build the fabrication structure, sometimes even impossible. We proposed a meth

英文关键词： flat-field concave grating；convex grating；holographically record；optical design；