Koike M, Namioka T
Appl Opt. 1997 Sep 1;36(25):6308-18. doi: 10.1364/ao.36.006308.
Comparative studies have been made on the holographic plane grating and the ruled varied-line-spacing (VLS) plane grating designed for two kinds of objective Monk-Gillieson type high-resolution grazing incidence monochromator, I and II. The ray-traced performance of monochromator types I and II on a synchrotron radiation beam line was evaluated in terms of resolving power and spectral purity by the introduction of new concepts of effective Gaussian line and purity profiles. The resolving power defined on the basis of the effective Gaussian profile is consistent with the spectral purity of the beam emerging from the exit slit and is more realistic as compared with those defined in the conventional manner, especially when spectral images have asymmetric profiles. It is concluded that holographic plane gratings recorded with a spherical and an aspheric wave front are capable of providing high resolution with high spectral purity and are fully interchangeable with the corresponding ruled VLS plane gratings. This interchangeability provides more flexibility for users in choosing a proper grating for a high-resolution grazing incidence monochromator of the Monk-Gillieson type.
针对两种目标型蒙克 - 吉利森（Monk - Gillieson）型高分辨率掠入射单色仪I和II所设计的全息平面光栅和刻划变线距（VLS）平面光栅，已经开展了对比研究。通过引入有效高斯线和纯度分布的新概念，从分辨率和光谱纯度方面对I型和II型单色仪在同步辐射光束线上的光线追迹性能进行了评估。基于有效高斯分布定义的分辨率与从出射狭缝出射的光束的光谱纯度一致，并且与传统方式定义的分辨率相比更符合实际情况，特别是当光谱图像具有不对称分布时。得出的结论是，用球面波前和非球面波前记录的全息平面光栅能够提供高分辨率和高光谱纯度，并且与相应的刻划VLS平面光栅完全可互换。这种互换性为用户在为蒙克 - 吉利森型高分辨率掠入射单色仪选择合适的光栅时提供了更大的灵活性。
