Simple empirical analytical approximation to the Voigt profile

A simple empirical analytical approximation to the Voigt profile is propose d as a weighted sum of Lorentzian and Gaussian functions. It is prevalent i n the analysis of complicated experimental spectra such as that with multib roadening mechanisms and congested or overlapped lines. The maximum errors of width, area, and peak relative to those from direct convolution of the V oigt profile are 0.01%, 0.2%, and 0.55%, respectively. The relative width e rror of the present approximation is smaller and its convergence of absolut e strength calculation, i.e. the area under the profile, faster than for th e other methods that we considered, such as Gautsch's algorithm, which is d eveloped by introduction of a complex probability function. (C) 2001 Optica l Society of America.