Negative polarization of light at backscattering from a numerical analog of planetary regoliths

Peculiarities of polarization at vicinity of near backscattering direction by atmospheric irregular crystal particles

“…In order to validate of our physical optics approximation (PO), Fig. 4b and 4d shows the calculations performed by numerically exact Discontinuous Galerkin Time Domain (DGTD) method [25][26][27]. Good agreement is obtained.…”

“…It is known that coherent backscattering is caused by the interference of a pair of light (conjugate) beams moving along the same trajectory, but in opposite directions. Therefore, the backscattering peak and the negative polarization [22][23][24][25] are created by interference within pairs of light beams propagating along the same trajectories in opposite directions. Figure 2 present the backscattering peak and negative polarization obtained as an expansion of the scattered light along the trajectories of light beams with different numbers of refraction/reflection events (for particle 3 from Fig.…”

Negative polarization phenomenon for large randomly oriented particles of irregular shapes

“…But only trajectories with four events (two internal reflections and two refractions at the exit faces) create negative polarization. This fact proves that there is a special physical mechanism that creates the phenomenon of negative polarization [23][24][25][26][27] , different from the mechanism that creates the backscatter peak. To explain the mechanism of formation of negative polarization, we consider pairs of plane-parallel beams emerging from a particle in the opposite direction for a fixed orientation of the particle.…”

Light scattering matrix for large irregularly shaped ice crystals averaged over an ensemble of particles

“…Even about 100 years ago 7 , when studying the scattering of solar radiation on the surfaces of celestial bodies in astrophysics, it was noticed that the degree of linear polarization of the *kustova@iao.ru scattered light becomes negative. Although several explanations for this phenomenon have been proposed so far, none has yet been found to be satisfactory [8][9][10][11][12][13][14] . For a more detailed analysis of the beam's trajectories that contribute to the negative polarization, let us average over an ensemble of particles consisting of 50 shapes of irregular particles.…”