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

Abstract

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

The Past and Future of the Monte Carlo Method in Thermal Radiation Transfer

“…Today, Monte Carlo is used to carry out simulations of scope and complexity that surely could not have been imagined by Ulam, von Neumann, Metropolis, and Fermi nearly 80 years ago. Recent examples include radiative loading on clouds, which is important for climate change modeling [118][119][120], radiative transfer within complex heterogeneous [121,122] and graded media [108,[123][124][125][126][127], polarization [128][129][130][131], shape optimization [69][70][71], computer graphics rendering [118], large scale systems [132,133], manufacturing [134][135][136][137], combined-mode problems [138][139][140][141][142][143][144], and others .…”

The dependent scattering effect on radiative properties of micro/nanoscale discrete disordered media

“…I b is the vector form of blackbody radiation as [I b 0 0 0] T because conventional thermal emission is unpolarized. κ a , κ e and Z(Ω , Ω) are the absorption, extinction and (unnormalized) phase matrices, respectively [17,82,83]. For a detailed description of the Stokes vector and its connection to the monochromatic transverse electromagnetic waves as well as these matrices, one can refer to Ref.…”

Depolarization Characteristics of Different Reflective Interfaces Indicated by Indices of Polarimetric Purity (IPPs)

“…As a famous geometrical optics model, the Torrance–Sparrow (T-S) model [ 15 ] has been widely investigated and expanded to the polarized BRDF (pBRDF) models [ 16 , 17 , 18 , 19 , 20 , 21 ]. The Monte Carlo (MC) method has also been introduced to solve the composition of samples in fusion devices or reactive plasmas and a series of cases about polarization information [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ], especially in photons tracking [ 24 , 25 , 29 , 30 ]. Wang et al have combined the MC model with BRDF, giving birth to a flexible method to acquire the reflective polarization information from a rough surface [ 34 ].…”