一种简单精确的CCD阵列光谱仪波长定标方法

A simple and accurate wavelength calibration method for CCD- spectrometer

波长定标是CCD光谱仪的重要步骤，其准确性会影响光谱仪测量结果的精确度。然而传统波长定标精度受仪器带宽和噪声的影响：带宽会导致定标光谱中产生重叠峰或双峰的峰位移；噪声会使峰值点的测量不准确。为解决这个问题，提出了一种简单精确的CCD光谱仪波长定标方法。使用自动分解算法和Voigt线状谱模型来优化定标光谱的形状，并且可以获得每个定标峰的峰值点的精确值。利用该方法可以消除带宽和噪声的影响，特别是重叠峰可以被同时分解成几个单峰，极大地简化了定标过程。实施基于USB4000光谱仪和汞氩校准光源的波长定标实验。结果表明，相比于传统方法，该方法可以达到较高的精度且定标误差小于0．1nm。因此，推荐使用该方法对光谱仪进行波长定标。

Wavelength calibration is an important step for CCD-spectrometers. The accuracy of the wavelength calibration will affect the precision of the measurement results. However, the accuracy of traditional wavelength calibration will be affected by instrument bandwidth and noise. The bandwidth of the instrument will generate the overlapping peaks in the calibration spectrum or cause the peak position shift of double peak. The noise will make inaccurate measurement of peak point. To solve this problem, a simple and accurate wavelength calibration method for CCD-spectrometer was proposed. The automated decomposition algorithm and Voigt line profile model were used to optimize the shape of the calibration spectrum and the precision value of the peak points of each calibration peak could be obtained. Using this method, the influence of bandwidth and noise could be eliminated, especially the overlap peaks could be decomposed into several single peaks, simultaneously, and the process of calibration was greatly simplified. Experiments based on USB4000 spectrometer with mercury-argon calibration light source were implemented. The results show that the proposed method could achieve higher accuracy and the calibration deviation is less than 0.1 nm. Therefore, it is recommended to use this method to calibrate the wavelength of the spectrometer.