中心波长的改变对色散型拉曼光谱仪测量精度的影响

Effect of Varying Central Wavelength on the Measurement Precision of Dispersive Raman Spectrometer

考虑拉曼频移的精确度对分析样品结构及内部的应力和掺杂等起至关重要的作用,研究了中心波长的改变对拉曼光谱仪测量精度的影响。首先通过研究拉曼散射光的波长与CCD像素的位置的对应关系,从理论上解释了中心波长的改变对拉曼光谱仪测量精度的影响。其次,以TiO_2粉末为实验对象,采用拉曼光谱仪在不同的中心波长下测其拉曼谱峰。实验结果表明:测量中更改不同的中心波长,即采谱范围的变化使测得的拉曼频移精度较差,标准偏差接近4cm^(-1);采谱范围变化后,光谱仪先经标准硅样校准测其拉曼频移精度较高,标准偏差小于1.5cm^(-1)。

As the precision of Raman shift plays an important role in the analysis of structure,the stress and doping of the samples,effect of central wavelength varying on the measurement precision of Raman spectrometer was studied. Firstly,the relationship between the wavelength of the Raman scattered light and the position of the CCD pixel was studied. The influence of central wavelength varying on the measurement precision of Raman spectrometer was explained theoretically. Finally,the Raman spectra of Ti O2 powders as the research object was measured at different central wavelength by Raman spectrometer. The experimental results showthat as a result of varying central wavelength,namely,variation of spectrum acquisition range,the measurement precision of Raman shift of TiO2 powder is poor and the standard deviation is close to 4 cm-1;if Raman spectrometer is firstly calibrated by standard silicon sample after variation of spectrum acquisition range,the measurement precision of Raman shift is higher and the standard deviation is less than 1. 5 cm-1.