The Institute of Optics, University of Rochester, Rochester, New York 14627, USA.
Appl Spectrosc. 2010 Jan;64(1):61-5. doi: 10.1366/000370210790571936.
A key design parameter in spatially offset Raman spectroscopy (SORS) is the choice of offset distance between the illumination and collection areas. To investigate this choice, we performed SORS measurements on a simple two-layer chemical phantom. We show that while the SORS ratio, or the ratio of signal from the bottom layer to the top layer, monotonically increases with spatial offset, the signal-to-noise ratio (SNR) does not. Specifically, we show that there exists a specific spatial offset that yields the best SNR for signal originating in the bottom layer of a two-layer sample. We also show that this SNR-optimal offset depends upon the strength of the particular Raman band. This work presents the considerations that should be taken into account when designing optical probes for use in SORS.
在空间偏移拉曼光谱（SORS）中，一个关键的设计参数是选择照明和收集区域之间的偏移距离。为了研究这个选择，我们对一个简单的双层化学模型进行了 SORS 测量。我们表明，虽然 SORS 比，或者底层信号与顶层信号的比值，随着空间偏移单调增加，但信噪比（SNR）却不会。具体来说，我们表明，在两层样品的底层信号中，存在一个特定的空间偏移，可产生最佳 SNR。我们还表明，这个 SNR 最优的偏移取决于特定拉曼带的强度。这项工作提出了在设计用于 SORS 的光学探头时应考虑的因素。
