全息反应离子束制作小阶梯光栅

发布时间：2018-03-20 01:19

本文选题：小阶梯光栅　切入点：闪耀角　出处：《中国科学技术大学》2016年硕士论文　论文类型：学位论文

【摘要】：阶梯光栅一般是指具有90°顶角的三角形槽型的闪耀光栅,通常有小阶梯光栅与中阶梯光栅之分。区别于中阶梯光栅,小阶梯光栅线密度较高,从上百线每毫米至上千线每毫米不等,且在较低的衍射级次发生“闪耀”,主要运用于天文光学望远镜中宽波段光谱探测的小阶梯光栅光谱仪。大口径光学望远镜的发展需要大口径、高效率、高衍射波前的阶梯光栅。其中透射闪耀阶梯光栅,尤其是光栅结构与棱镜结合的棱栅,具有光路简单,能有效节约空间的优点,近年来受到青睐。机械刻划通常被用来制作反射阶梯光栅,而全息-离子束刻蚀技术制作光栅,具有高效率、无鬼线、杂散光较少的优点,更重要的是,容易在石英的透明基底表面制作透射光栅。本文探索使用全息反应离子束刻蚀制作小阶梯光栅的工艺方法。先以光刻胶为掩模垂直刻蚀,之后以矩形石英光栅为掩模,即同质掩模,进行倾斜离子束刻蚀,改变离子束的入射角以制作不同闪耀角的光栅；在倾斜刻蚀中观察分析了掩模阴影中的再沉积对槽型的影响,得到了在再沉积作用下离子束入射角与闪耀角的关系曲线：探索在离子束入射角较小且刻蚀方向不变的情况下,延长刻蚀时间改变光栅槽型顶角的方法,并使用此方法将离子束30°入射所制作光栅的顶角由44°变为78°。最终通过实验成功制作出线密度3601p/mm,闪耀角为16.8°,以及线密度为4001p/mm,闪耀角为34.7°和43°的小阶梯光栅。对+1级闪耀级次的透射衍射效率进行了测量,结果表明在光栅的工作波段的衍射效率基本在理论值的75%以上。在保证衍射效率的基础上拓展了全息离子束工艺制作闪耀光栅的范围,对今后全息离子束制作小阶梯光栅提供参考。
[Abstract]:A ladder grating is generally a blazed grating with a triangular groove with a 90 掳vertex angle, which is usually divided between a small step grating and a middle step grating, which is different from the middle step grating in that the linear density of the small step grating is relatively high. Ranging from hundreds of wires per millimeter to thousands of lines per millimeter, And "sparkle" occurs in the lower diffraction order, which is mainly used in the small step grating spectrometer for wide-band spectral detection in astronomical optical telescopes. The development of large-aperture optical telescopes requires large aperture and high efficiency. The transmission blazed step grating, especially the grating which combines the grating structure with the prism, has the advantages of simple optical path and space saving. In recent years, mechanical scratches are often used to fabricate reflective step gratings, while holographic and ion beam etching techniques have the advantages of high efficiency, no ghost lines, less stray light, and, more importantly, It is easy to fabricate transmission gratings on the transparent substrate surface of quartz. In this paper, a method of fabricating small step gratings by holographic reactive ion beam etching is explored. Firstly, the photoresist is used as the mask for vertical etching, and then the rectangular quartz grating is used as the mask. That is, the homogeneous mask is etched by inclined ion beam, the incident angle of ion beam is changed to make grating with different blazing angles, and the influence of redeposition in the mask shadow on the groove type is observed and analyzed in the oblique etching. The relation curve between the incident angle and the blazing angle of ion beam under redeposition is obtained. Under the condition that the incident angle of ion beam is small and the etching direction is constant, the method of extending the etch time to change the top angle of grating groove is explored. Using this method, the vertex angle of the grating produced by 30 掳incident ion beam was changed from 44 掳to 78 掳. Finally, the linear density 3601pr / mm, blazing angle 16.8 掳and linear density 4001p / mm, blazing angle 34.7 掳and 43 掳were successfully fabricated. The transmission diffraction efficiency of the first order of the blazing order was measured. The results show that the diffraction efficiency in the working band of the grating is above 75% of the theoretical value. On the basis of ensuring the diffraction efficiency, the range of the holographic ion beam technology for making blazed gratings is expanded. It provides a reference for the fabrication of small step gratings by holographic ion beam in the future.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN25

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