相关诱导光谱变化对光谱测量的影响

The effect of correlation-induced spectral change on spectral measurement

在光传播空间中引入的光阑会对光谱的传播产生影响。以一个常用的光谱测量系统为模型,对系统中的光阑对光谱变化的影响进行了深入的研究。研究结果表明,狭缝的衍射和透镜的色差以及光源的空间相干度的变化都有可能使衍射场中观察点的光谱出现变化,并且这种变化与观察点的空间位置有关。这种相关诱导光谱变化会对光谱的精确测量产生影响。

In the scope of spectral measurement and analysis, it is implicit that the nomalized spectral distribution can re- main invariant while propagation. It is shown that the assumption is only correct in certain case. The aperture located in the space where the light propagates has effect on the spectrum. Based on an experimental setup which is widely used in the mea- surement of spectrum, the effect of the aperture in the system on the spectral change is investigated. It is found that the nor- malized spectral distribution can change while propagation if the light is diffracted by a slit or focused by a lens with chromatic aberration. Moreover the spectral change relates to the location of the observation point. The correlation-induced spectral change can play a vital part in the precise t of spectrum