佛克脱光谱线型干涉图的理论及其应用研究

Research on Theory and Application of the Interferogram of Voigt Profile

在一般压强的条件下,佛克脱光谱线型(高斯光谱线型和洛伦兹光谱线型的卷积)是最接近实际的光谱线型,但由于其没有具体的表达式,所以在实际应用中常采用各种近似来表示佛克脱光谱线型。文章未采用任何近似,计算了佛克脱光谱线型干涉图的具体表达式,表明虽然佛克脱光谱线型没有具体表达式,但其干涉图是可以严格求解的。而且其变换结果为一实函数,与高斯光谱线型和洛伦兹光谱线型的变换结果的表达式非常相似,因而可以进行谱线综合展宽的各种计算,而不是像有的文献所预言的有实部和虚部两部分,给计算带来困难。计算结果与实验结果一致。作为应用的一个实例,作者指出了其在大气风场测量中的重要应用。此计算对气体展宽在傅里叶变换光谱仪中的应用方面具有非常重要的意义。

At normal pressure, Voigt profile （the convolution of Gaussian profile and Lorentzian profile） is the closest to actual profile, but it has no accurate expression, so in actual application many approximations are used to express Voigt profile. In the present paper, without any approximation, the authors calculate the interferogram of Voigt profile, showing that Voigt profile has no expression, but its interferogram can be calculated strictly. The transform has only one term, which is very similar to the expressions of Gaussian profile and Lorentzian profile, so any calculations of the widened profile can be finished, which doesn＇t have two terms as some papers predict, and difficulties will be brought. The calculation results are consistent with the experimental results. As an example in actual application, its application in atmospheric wind measurement is pointed out. This calculation has important significance in Fourier transform spectrometer of gas widened profile.