Liu Dongyue, Hennelly Bryan M
Department of Electronic Engineering, Maynooth University, Kildare, Ireland.
Department of Computer Science, Maynooth University, Kildare, Ireland.
Appl Spectrosc. 2024 Aug;78(8):790-805. doi: 10.1177/00037028241254847. Epub 2024 Jun 2.
A wavenumber calibration protocol is proposed that replaces polynomial fitting to relate the detector axis and the wavenumber shift. The physical model of the Raman spectrometer is used to derive a mathematical expression relating the detector plane to the wavenumber shift, in terms of the system parameters including the spectrograph focal length, the grating angle, and the laser wavelength; the model is general to both reflection and transmission gratings. A fast search algorithm detects the set of parameters that best explains the position of spectral lines recorded on the detector for a known reference standard. Using three different reference standards, four different systems, and hundreds of spectra recorded with a rotating grating, we demonstrate the superior accuracy of the technique, especially in bands outside of the outermost reference peaks when compared with polynomial fitting. We also provide a thorough review of wavenumber calibration for Raman spectroscopy and we introduce several new evaluation metrics to this field borrowed from chemometrics, including leave-one-out and leave-half-out cross-validation.
提出了一种波数校准协议，该协议取代了用于关联探测器轴和波数偏移的多项式拟合。拉曼光谱仪的物理模型用于根据包括光谱仪焦距、光栅角度和激光波长在内的系统参数，推导将探测器平面与波数偏移相关联的数学表达式；该模型对反射光栅和透射光栅均通用。一种快速搜索算法可检测出能最佳解释已知参考标准在探测器上记录的谱线位置的参数集。使用三种不同的参考标准、四种不同的系统以及数百个用旋转光栅记录的光谱，我们证明了该技术具有更高的准确性，特别是与多项式拟合相比，在最外层参考峰之外的波段中。我们还对拉曼光谱的波数校准进行了全面回顾，并引入了从化学计量学借用的该领域的几个新评估指标，包括留一法和留半法交叉验证。
