Mechanisms of ultrasonic modulation of multiply scattered coherent light: An analytic model - art. no. 043903

An analytic model of the ultrasonic modulation of multiply scattered cohere nt light in scattering media is developed based on two mechanisms: the ultr asonic modulation of the index of refraction and the ultrasonic modulation of the displacements of Rayleigh scatterers. In water solutions, for exampl e, the first mechanism is slightly less important than the second mechanism when the scattering mean free path is less than a critical fraction (0.089 0) of the acoustic wavelength, and it becomes increasingly more important b eyond this point. This model agrees well with an independent Monte Carlo mo del.