Monte Carlo method for polarized radiative transfer in gradient-index media

摘要

Light transfer in gradient-index media generally follows curved raytrajectories, which will cause light beam to converge or diverge duringtransfer and induce the rotation of polarization ellipse even when the mediumis transparent. Furthermore, the combined process of scattering and transferalong curved ray path makes the problem more complex. In this paper, a MonteCarlo method is presented to simulate polarized radiative transfer ingradient-index media that only support planar ray trajectories. The rayequation is solved to the second order to address the effect induced by curvedray trajectories. Three types of test cases are presented to verify theperformance of the method, which include transparent medium, Mie scatteringmedium with assumed gradient index distribution, and Rayleigh scattering withrealistic atmosphere refractive index profile. It is demonstrated that theatmospheric refraction has significant effect for long distance polarized lighttransfer.