Spectral line shape

Absorption spectrum of an aqueous solution of potassium permanganate. The spectrum consists of a series of overlapping lines belonging to a vibronic progression

Spectral line shape or spectral line profile describes the form of an electromagnetic spectrum in the vicinity of a spectral line – a region of stronger or weaker intensity in the spectrum. Ideal line shapes include Lorentzian, Gaussian and Voigt functions, whose parameters are the line position, maximum height and half-width.[1] Actual line shapes are determined principally by Doppler, collision and proximity broadening. For each system the half-width of the shape function varies with temperature, pressure (or concentration) and phase. A knowledge of shape function is needed for spectroscopic curve fitting and deconvolution.

  1. ^ Hollas, M.J. (1996). Modern Spectroscopy (3rd ed.). Wiley. pp. 30–34. ISBN 0471965227.