title: Light distributions in artery tissue: Monte Carlo simulations for finite-diameter laser beams.
abstract: Finite-width light distributions in arterial tissue during Argon laser irradiation (476 nm) are simulated using the Monte Carlo method. Edge effects caused by radial diffusion of the light extend +/- 1.5 mm inward from the perimeter of a uniform incident beam. For beam diameters exceeding 3 mm the light distribution along the central axis can be described by the one-dimensional solution for an infinitely wide beam. The overlapping edge effects for beam diameters smaller than 3 mm reduce the penetration of the irradiance in the tissue. The beam profile influences the light distribution significantly. The fluence rates near the surface for a Gaussian beam are two times higher on the central axis and decrease faster radially than for a flat profile. The diverging light from a fiber penetrates tissue in a manner similar to collimated light.
authors.affiliation: Department of Dermatology, Wellman Laboratory, Harvard Medical School, Massachusetts General Hospital, Boston.
authors.forename: M
authors.initials: M
authors.lastname: Keijzer
authors.forename: S L
authors.initials: SL
authors.lastname: Jacques
authors.forename: S A
authors.initials: SA
authors.lastname: Prahl
authors.forename: A J
authors.initials: AJ
authors.lastname: Welch
mesh_terms: D001011:Aorta; D006801:Humans; D007834:Lasers; D008027:Light; D009010:Monte Carlo Method; D009874:Operations Research; D012542:Scattering, Radiation