光电探测器对光谱仪器精度的影响

The Effect of the Photoelectric Detector on the Accuracy of the Spectrometer

通过优化光谱探测环节来提高光谱仪器的精度是改进或研制新型光谱仪的重要途径。为此,文章基于对光电成像系统中光学传递函数的研究,建立了光谱图像经探测器积分抽样后重建的数学模型,并在此基础上分析了光电探测器积分抽样特性参数对光谱线频谱的影响,讨论了光谱线半宽度与探测器积分区间宽度、灵敏度及抽样间隔的关系,提出了准确重建光谱线,提高光谱仪器波长精度和光度精度的探测器优化原则。

An optimized photoelectric detector will increase the precision of a spectrometer, thus indicates an important way to develop high performance spectrometer. With an eye to this, a model describing the process that spectrogram is integrated and sampled by photoelectric detector and restored after low-pass filtering is developed. Based on the model, the influence of the characteristic parameters of the detector on the spectral line in the frequency domain is analyzed and the relation between the full width half maximum （FWHM） of the spectra line and the integral interval, sampling space and sensitivity of the detector is deduced. The conclusion indicates that both the integral interval and sampling space should be 1/6 of the FWHM for a spectral line with gaussian profile as a result of compromise between accuracy and feasibility. Moreover, the critical point deciding the right situation for scanner and array detector is given. Other guide line to optimize the photoelectric detector and increase accuracy is suggested also.