Instrumental Effects on Brillouin Line Shapes

Instrumental distortions of the Brillouin light spectrum induce systematic errors into the observed sound velocity and sound absorption. A model is given by which certain distortions may be reduced. The model involves Voigt functions, which are a generalization of Gaussian and Lorentzian functions. It is shown that corrections in general involve both an instrumental linewidth and a parameter which measures the line shape of the instrumental spectrum.