Curvature correction and Mie scattering in Monte Carlo analysis of propagating focused Gaussian beam in scattering media

  • Hannah Christina Chan Arjonillo National Institute of Physics, University of the Philippines Diliman
  • Caesar Saloma National Institute of Physics, University of the Philippines Diliman

Abstract

We introduce curvature correction to set the photon-step size and initial photon distribution in the focusing lens aperture to account for the effect of the radius of curvature of a Gaussian beam propagated towards a scattering medium. It improves the accuracy of the Monte Carlo simulation results with decreasing step size s and increasing number of steps Ns. In the absence of scattering, the axial beam distribution approaches the prediction of the scalar diffraction theory for a given numerical aperture NA, s, and Ns based on the Linfoot's criteria. Mie scattering theory is employed to calculate the particle radius, density, and phase distribution needed for a desired degree of scattering and anisotropy. Ray-tracing algorithms are used to determine the scattering events. We discuss how the simulation performs for random scattering media consisting of spherical scatterers based on the obtained axial intensity and mean free path, and explore its behavior in periodic media.

Published
2019-05-21
How to Cite
[1]
H. C. Arjonillo and C. Saloma. Curvature correction and Mie scattering in Monte Carlo analysis of propagating focused Gaussian beam in scattering media, Proceedings of the Samahang Pisika ng Pilipinas 37, SPP-2019-PB-20 (2019). URL: https://paperview.spp-online.org/proceedings/article/view/SPP-2019-PB-20.