Mende S B, Claflin E S, Rairden R L, Swenson G R
Appl Opt. 1993 Dec 1;32(34):7095-105. doi: 10.1364/AO.32.007095.
In a conventional grating spectrograph consisting of a single entrance slit, a grating, and a multichannel (imaging) detector, considerable light throughput advantage can be realized by replacement of the single entrance slit with a mask. This replacement can yield a signal-to-noise ratio increase because of increased light collection over an extended area of the mask when compared with a single slit. The mask produces a spectrum on the detector, which is the convolution of the mask pattern and the spectral distribution of the light source. To retrieve the spectrum, the spectrum has to be inverted. In special cases in which emission spectra are superimposed on weak backgrounds, the signal-to-noise advantage is preserved through the inversion process. Thus this technique is valuable in the observation of light sources that are produced by atomic or molecular emissions such as aurora, airglow, some interstellar emission, or laboratory spectra. Considerable signal-to-noise advantages can also be realized when the background noise of the imaging detector is not negligible. The spectral mixing of the light from the mask on the detector causes high photon fluxes on the detector, which tend to swamp the detector noise. This is a particularly important advantage in the application of CCD's as detectors because they can have significant background noise. The technique was demonstrated by computer simulations and laboratory tests.
在由单个入射狭缝、一个光栅和一个多通道（成像）探测器组成的传统光栅光谱仪中，用一个掩模替代单个入射狭缝可实现显著的光通量优势。与单个狭缝相比，这种替代由于在掩模的扩展区域上增加了光收集，可提高信噪比。掩模在探测器上产生一个光谱，它是掩模图案与光源光谱分布的卷积。为了恢复光谱，必须对光谱进行反演。在发射光谱叠加在弱背景上的特殊情况下，通过反演过程可保持信噪比优势。因此，该技术在观测由原子或分子发射产生的光源，如极光、气辉、一些星际发射或实验室光谱时很有价值。当成像探测器的背景噪声不可忽略时，也可实现显著的信噪比优势。来自掩模的光在探测器上的光谱混合会导致探测器上的高光子通量，这往往会掩盖探测器噪声。这在将电荷耦合器件用作探测器的应用中是一个特别重要的优势，因为它们可能有显著的背景噪声。该技术已通过计算机模拟和实验室测试得到验证。
