[Research on theory and application of the interferogram of Voigt profile]

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.