Zhang Lichao, Lin Hui, Jin Chunshui, Zhou Hongjun, Huo Tonglin
State Key Lab of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, China.
Opt Lett. 2009 Mar 15;34(6):818-20. doi: 10.1364/ol.34.000818.
Diffraction gratings used in extreme UV are typically coated with periodic multilayer thin films. These coatings have a small bandwidth, thus leading to a narrow usable spectral region of multilayer gratings. Well-designed aperiodic multilayer coatings could provide high reflectivity over a much broader wavelength region, so they could broaden the usable spectral region of multilayer gratings. We designed and deposited an aperiodic Mo/Si multilayer coating onto a blazed grating substrate. At an incidence angle of 10 degrees, the -2nd-order diffraction efficiency of the multilayer grating is approximately 10% through the wavelength range of 13-16 nm.
极紫外波段使用的衍射光栅通常涂覆有周期性多层薄膜。这些涂层带宽较小，因此导致多层光栅的可用光谱区域较窄。精心设计的非周期性多层涂层可以在更宽的波长区域提供高反射率，从而拓宽多层光栅的可用光谱区域。我们在闪耀光栅基板上设计并沉积了一种非周期性Mo/Si多层涂层。在10度入射角下，多层光栅在13 - 16纳米波长范围内的 - 2级衍射效率约为10%。
