We propose and theoretically analyze a single-order diffractive optical element, termed binary sinusoidal multilayer grating (BSMG), to effectively suppress high-order diffractions while retaining high diffraction efficiency in the first order. The key idea is to integrate sinusoidal-shaped microstructures with high-reflectivity multilayer coatings. The dependence of the high-order diffraction property on the microstructure shape and multilayer coatings is investigated. Theoretical calculation reveals that the second-, third-, fourth-, and fifth-order diffraction efficiencies are as low as 0.01%. Strikingly, we show that first-order relative diffraction efficiency (the ratio between the intensity of the first diffraction order versus that of the reflected light) as high as 97.7% can be achieved. Thus, the proposed BSMG should be highly advantageous in future development and application of tender x-ray spectroscopy.

中文翻译：

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二阶正弦波单阶多层光栅，用于柔和的X射线区域。

我们提出并从理论上分析了一种称为二元正弦多层光栅（BSMG）的单阶衍射光学元件，以有效抑制高阶衍射，同时保持一阶高衍射效率。关键思想是将正弦形微结构与高反射率多层涂层集成在一起。研究了高阶衍射特性对显微组织形状和多层涂层的依赖性。理论计算表明，二，三，四和五阶衍射效率低至0.01％。令人惊讶地，我们表明可以实现高达97.7％的一级相对衍射效率（一级衍射强度与反射光强度之比）。从而，