Regensburg 2010 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 21: Neurobiophysics and Sensory Transduction

BP 21.10: Vortrag

Mittwoch, 24. März 2010, 16:45–17:00, H43

Analytical multi-particle scattering model for the simulation of light propagation through biological tissue — •Lars Boyde — Biological and Soft Systems, University of Cambridge, UK

The scattering of light from an assembly of arbitrarily arranged, dielectric particles has a multitude of applications in the fields of physics, biology, and medicine. Specific examples include aerosol scattering, remote sensing, radiative transfer, and the propagation of light through biological tissue, such as the retina of the eye.

The author developed and implemented an analytical model that can be used to compute the electromagnetic near- and far-field intensities for the incidence of a plane wave or Gaussian laser beam on an ensemble of dielectrically coated particles. The underlying theoretical basis of the model is the solution of Maxwell’s equations using Mie theory and the so-called vector translation theorems which facilitate the transformation of the fields between the coordinate systems of the individual particles.

The model has been applied to simulate the propagation of light through the outer nuclear layer of the retina in the mammalian eye – one of the crucial stages of light transmission in the process of vision. Using the established properties of the photoreceptor cell (PRC) nuclei embedded in this layer, the simulations conclusively show that the PRC nuclei of nocturnal animals act as strongly focusing micro-lenses. Unlike their diurnal counterparts, the chromatin-inverted, nocturnal PRC nuclei effectively channel light onto the light-sensitive outer segments of the rods and cones, leading to enhanced night vision.