Sandfuchs Oliver, Kraus Matthias, Brunner Robert
J Opt Soc Am A Opt Image Sci Vis. 2020 Aug 1;37(8):1369-1380. doi: 10.1364/JOSAA.392691.
The majority of spectrometers use reflective dispersion gratings with a metal-coated blazed grating profile for spectral decomposition. They achieve high diffraction efficiency at the design wavelength, which decays considerably in the adjacent longer and shorter wavelength ranges. We introduce a structured metal double-blazed grating with a high diffraction efficiency for a broadband spectral range, consisting of a sawtooth-like structured metal surface filled with a first dielectric transparent material. The planarized upper surface is covered with a second blazed profile of a different transparent material. We present a systematical theoretical analysis of the diffraction efficiency in reflection geometry, based on a scalar approach involving fundamental dispersion parameters such as Abbe numbers and relative partial dispersions of the materials. We find material combinations reducing the profile heights down to 1-2 µm.
大多数光谱仪使用具有金属涂层闪耀光栅轮廓的反射色散光栅进行光谱分解。它们在设计波长处实现了高衍射效率，而在相邻的较长和较短波长范围内，衍射效率会大幅下降。我们引入了一种用于宽带光谱范围的具有高衍射效率的结构化金属双闪耀光栅，它由填充有第一介电透明材料的锯齿状结构化金属表面组成。平坦化的上表面覆盖有不同透明材料的第二闪耀轮廓。我们基于涉及诸如材料的阿贝数和相对部分色散等基本色散参数的标量方法，对反射几何结构中的衍射效率进行了系统的理论分析。我们发现了能将轮廓高度降低至1 - 2微米的材料组合。
