Light Propagation in turbid media

Participants: Erick Sarmiento (in collaboration with Beatriz Morales, Engineering Faculty, UASLP)

A homogeneous media is transparent due to rectilinear propagation of rays, or, under the vision of electromagnetic waves, due to wave front propagation without deformation. A colloidal suspension, in the opposite, is turbid, meaning that light is not propagating in a rectilinear way anymore. This effect is called scattering, and is commonly found in inhomogeneous materials, i.e. in materials with position-dependent refractive index. In a turbid media, direction of propagation of light continuously changes, and in some cases, molecules absorb part of the incident energy. In dynamic light scattering techniques, light exiting a colloidal suspension is analyzed and dynamical properties of the scattering particles (colloidal particles) are extracted from the time evolution of intensity. However, this kind of techniques requires a model for light propagation, and also requires mesoscopic properties that characterize the scattering process, such as the so called optical properties. We are currently using models for light propagation, such as GPU accelerated Monte Carlo simulations, to develop techniques that could allow the extraction of optical properties required in dynamic light scattering techniques, and also exploring the possibilities of more general light scattering techniques, not only in complex fluids applications, but also in biomedical applications.

Last Uptade: January 2015