Propagation of photon-density waves in strongly scattering media containing an absorbing semi-infinite plane bounded by a straight edge

Journal Article · Fri Jan 01 00:00:00 EST 1993 · Journal of the Optical Society of America, Part A: Optics and Image Science; (United States)

DOI:https://doi.org/10.1364/JOSAA.10.000127· OSTI ID:6712649

Fishkin, J B; Gratton, E ^[1]

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1. Univ. of Illinois, Urbana (United States)

Light propagation in strongly scattering media can be described by the diffusion approximation to the Boltzmann transport equation. The authors have derived analytical expressions based on the diffusion approximation that describe the photon density in a uniform, infinite, strongly scattering medium that contains a sinusoidally intensity-modulated point source of light. These expressions predit that the photon density will propagate outward from the light source as a spherical wave of constant phase velocity with an amplitude that attenuates with distance r from the source as exp([minus]r)/r. The properties of the photon-density wave are given in terms of the spectral properties of the scattering medium. The authors have used the Green's function obtained from the diffusion approximation to the Boltzmann transport equation with a sinusoidally modulated point source to derive analytic expressions describing the diffraction and the reflection of photon-density waves from an absorbing and/or reflecting semi-infinite plane bounded by a straight edge immersed in a strongly scattering medium. The analytic expressions given are in agreement with the results of frequency-domain experiments performed in skim-milk media and with Monte Carlo simulations. These studies provide a basis for the understanding of photon diffusion in strongly scattering media in the presence of absorbing and reflecting objects and allow for a determination of the conditions for obtaining maximum resolution and penetration for applications to optical tomography. 20 refs., 21 figs., 1 tab.

• OSTI ID: 6712649
• Journal Information: Journal of the Optical Society of America, Part A: Optics and Image Science; (United States), Vol. 10:1; ISSN 0740-3232
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EQUATIONS
ANALYTICAL SOLUTION
PHOTONS
DIFFUSION
SCATTERING
WAVE PROPAGATION
PHASE VELOCITY
BOLTZMANN EQUATION
DIFFRACTION
GREEN FUNCTION
MONTE CARLO METHOD
REFLECTION
RESOLUTION
TOMOGRAPHY
BOSONS
CALCULATION METHODS
COHERENT SCATTERING
DIAGNOSTIC TECHNIQUES
DIFFERENTIAL EQUATIONS
ELEMENTARY PARTICLES
FUNCTIONS
MASSLESS PARTICLES
PARTIAL DIFFERENTIAL EQUATIONS
VELOCITY
661300* - Other Aspects of Physical Science- (1992-)