The experimental technique and the general theory of the hakenmethode (hook method or dispersion method) is reviewed. The review presents the basic experimental arrangement for the formation of hooks in a crossed interferometer-spectrometer system and the experimental parameters of importance of an f-value measurement by the hakenmethode. The significance of the complex index of refraction of a dispersive and dissipative medium and its relation to the hakenmethode technique, as applied to single- and multiple-line spectra is described in some detail. Penkin’s total absorption method for measuring absolute f values by combining the hakenmethode with absorption measurements is reviewed. A method (similar to a Voigt profile analysis) is introduced for studying the formation of hooks about spectral lines whose absorption widths may be an appreciable fraction of the hook separation.
W. C. Marlow, "Hakenmethode," Appl. Opt. 6, 1715-1724 (1967)