凸面光栅的设计与制作研究进展

Research Progress in Design and Fabrication of Convex Grating

凸面光栅是Offner结构成像光谱仪的核心分光元件,制备出高衍射效率、高分辨率的凸面光栅是提高光谱仪成像质量,实现遥感探测的关键。介绍了目前凸面光栅的研究现状,讨论了设计与制作凸面闪耀光栅的主要方法。凸面光栅的设计方法采用严格耦合波理论对光栅进行衍射效率分析,制作方法主要包括:电子束直写法、X射线光刻法、机械刻划法以及全息离子束刻蚀法。鉴于全息离子束刻蚀法具有成本低、槽型可控、无鬼线等优点,详细介绍了利用该方法制备凸面光栅的工艺及相关研究报道。在接下来的工作中将不断优化和提高全息曝光光强分布的均匀性,改进摆动刻蚀装置旋转轴的可调性,优化离子束刻蚀工艺参数,以期制作出实用化的凸面闪耀光栅。

Convex grating is the core of Offner structure imaging spectrometers. To improve the imaging quality of a spectrometer and realize remote sensing detection, it is key to use convex grating with high diffraction efficiency and high resolution. The diffraction efficiency of convex gratings is analysed by strictly coupled wave theory. In this study, we present the research status of convex grating and discuss the main methods for designing and manufacturing convex blazed grating, including electron beam direct writing, X-ray lithography, mechanical etching, and holographic ion beam etching. Owing to the advantages of holographic ion beam etching, such as low cost, controllable groove type, and ghost-free, we introduce in detail the fabrication of convex grating via holographic ion beam etching and present related studies. Based on the investigation and analysis, we aim to optimize and improve the uniformity of the light intensity distribution of holographic exposure, the adjustable rotation axis of swing-etching device, and the process parameters of ion beam etching to produce a practical convex-blazed grating.