Seely J F, Brown C M
Appl Opt. 1993 Nov 1;32(31):6288-93. doi: 10.1364/AO.32.006288.
The performance of a spectrometer that uses a blazed multilayer-coated grating and that is based on the Seya-Namioka mount is analyzed. In the extreme-UV wavelength region, the efficiency of the grating is relatively high in a narrow bandpass that is defined by the reflectance of the multilayer coating. The bandpass can be shifted in wavelength by rotation of the grating, as is the case for the Seya-Namioka mount, for which the angle of incidence on the grating is near 35°. It is shown that when the source is slightly off the Rowland circle, as occurs when the grating is rotated and the source-to-grating distance is fixed, one can maintain good focusing can be maintained by moving the detector over a small range of distance and angle. The multilayer coating can be designed so that the grating remains on-blaze in wavelength regions of interest and in particular orders as the grating is rotated. A spectrometer composed of a multilayer grating and a movable detector can have relatively high throughput and resolving power in the extreme-UV region. When the grating is rotated, the wavelength coverage is wider than is the case for incidence angles near normal.
分析了一种采用闪耀多层镀膜光栅且基于塞亚-南米奥卡装置的光谱仪的性能。在极紫外波长区域，光栅在由多层镀膜的反射率所定义的窄带通内效率相对较高。如塞亚-南米奥卡装置那样，通过旋转光栅可使带通的波长发生偏移，该装置中光栅的入射角接近35°。结果表明，当光源稍微偏离罗兰圆时，如旋转光栅且光源到光栅的距离固定时所发生的情况，通过在小距离和小角度范围内移动探测器可保持良好的聚焦。多层镀膜可设计成使光栅在旋转时在感兴趣的波长区域以及特定级次下保持闪耀。由多层光栅和可移动探测器组成的光谱仪在极紫外区域可具有相对较高的通量和分辨率。当光栅旋转时，波长覆盖范围比接近法线入射角时的情况更宽。
