Abstract: Light propagation in turbid media can be described by photon diffusion. In the frequency domain, sinusoidally intensity-modulated light gives rise to diffusive waves which have a coherent front. In a homogeneous medium, the wave front propagates with a constant phase velocity and the amplitude attenuates exponentially as the diffusional wave advances. We have studied the diffusion approximation to the one-speed linear transport equation with a sinusoidally intensity modulated point source of particles and performed experiments using frequency domain detection methods on homogeneous scattering and absorbing media to test the applicability of the above mentioned transport equation to photon migration in turbid media. We have used the analytical solutions of the linear transport equation in homogeneous, infinite media to determine via a simple analysis of our frequency domain data the linear scattering and absorption coefficients.!
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