基于棱镜扫描法的太阳光谱仪光谱定标

为了标定扫描式棱镜太阳光谱仪的棱镜不同转动角度对应的中心波长和光谱带宽，利用了一种棱镜扫描方法对太阳光谱仪的光谱响应函数进行测量。该方法使用固定的单色光波长，控制棱镜转动实现单色光的像在探测器位置扫描，并通过坐标映射得到响应位置的光谱响应函数。文中根据光谱响应函数的定义，推导出棱镜扫描法与单色仪波长扫描方法波长定标原理上的等效性。之后分别以532 nm固体激光器和632.8 nm氦氖激光器为光源，使用棱镜扫描法测量太阳光谱仪对应波长位置的光谱响应函数，并以单色仪波长扫描法实验作为对比。实验结果表明，对于扫描式棱镜太阳光谱仪，棱镜扫描法测量的中心波长分别为531.86和632.67 nm，其准确度优于单色仪波长扫描法测得的531.39和631.97 nm。由于不受单色仪性能的限制，前者测量的光谱带宽值也优于后者。最后以汞灯为光源使用棱镜扫描法对太阳光谱仪进行了光谱定标实验，实现了特征光谱定标法结合棱镜扫描法对中心波长及光谱带宽的标定。该方法同样可以应用于扫描式光栅光谱仪以及单色仪的光谱定标。

Spectral Calibration of a Solar Spectrometer Based on the Prism-Rotating Method

In order to calibrate the corresponding center wavelength and bandwidth to the prism ’s rotating angle of a scanning prism‐dispersive solar spectrometer ,a prism‐rotating method to measure the spectral response function (SRF) of the solar spec‐trometer is suggested .The measuring process is as follows .With the wavelength of monochromatic light invariant ,the prism is rotated for scanning the monochromatic image at the location of detector .Then the spectral response function is obtained by mapping the coordinate in position to the coordinate in wavelength .At first in this paper ,by analyzing the definition of SRF ,the conclusion is deduced that the prism‐rotating method is equivalent to the wavelength‐scanning method in practice .Then the 532 nm solid‐state laser and 632.8 nm He‐Ne laser are used as light source .The measurement of SRF of the solar spectrometer based on prism‐rotating method is performed .A measurement of SRF with wavelength‐scanning method is also performed to be used as a comparison .Experimental results indicate that the center wavelength of the scanning prism‐dispersive solar spectrometer meas‐ured with prism‐rotating method is 531.86 and 632.67 nm respectively .On the other hand ,the result is 53139 and 631.97 nm with wavelength‐scanning method ,which is less precise than the result of prism‐rotating method .The values of bandwidth measured with prism‐rotating method are also more precise than the latter owing to avoiding the performance deficiency of mono ‐chromator .At last ,using mercury vapor lamp as light source ,an experiment for spectral calibration of the solar spectrometer with prism‐rotating method is performed .The values of center wavelength and bandwidth are both achieved with the method combining the prism‐rotating method and chracteristic spectrum .This method can also be used to calibrate the monochromator and the grating‐dispersive spectrometer whose grating is rotatable .