通过摆动离子束刻蚀方法, 制作了用于短波红外高光谱成像光谱仪的凸面闪耀光栅。该方法通过在光栅子午方向上进行摆动刻蚀, 解决了凸面光栅子午方向的闪耀角一致性问题。建立了摆动刻蚀模型来分析摆动速度、束缝宽度等工艺参数对槽型演化的影响, 并计算了优化的刻蚀工艺参数。制备了基底尺寸为67 mm, 曲率半径为156.88 mm, 刻线密度为45.5 gr/mm, 闪耀角为2.2°的凸面闪耀光栅, 并对其表面形貌及衍射效率进行了测量。实验结果表明, 摆动刻蚀法能够制作出闪耀角一致性好、衍射效率高的小闪耀角凸面光栅, 满足成像光谱仪对光谱分辨率和便携性的使用要求。

We use the swing ion-beam etching method to fabricate short wave infrared convex blazed gratings. This method solves the consistency problem of blaze angles by swing etching through the meridian direction of the gratings. A geometric model is built to analyze the influence of swinging speed and beam slit width on groove evolution. Convex gratings with a 45.5 gr/mm groove density, 67 mm aperture, 156.88 mm radius of curvature and 2.2° blaze angle have been fabricated and measured. Experimental results validate that high-efficiency convex gratings of small blaze angle and high groove consistency can be produced by swing etching to satisfy the requirements for high spectral resolution and miniaturization of imaging spectrometers.