Numerical analysis of the coherent mechanism producing negative polarization at backscattering from systems of absorbing particles

We study a double-scattering coherent mechanism of negative polarization (NP) near opposition that is observed for powder-like surfaces. The problem is solved numerically for absorbing structures with irregular constituents, cubes, spheres, and ellipsoids larger than thewavelength of incident light. Our simulations show that double scattering between two random irregular particles shows weak NP. Adding one more particle significantly increases the relative contribution of double scattering which enhances NP. Simulations with regular shapes and controlled geometric parameters show that the interference mechanism is sensitive to the geometry of the scattering system and can also result in no polarization or even strong enhancement of positive polarization at backscattering. (C) 2021 Optica Publishing Group

Automated summary

This study investigates the double-scattering coherent mechanism of negative polarization observed for powder-like surfaces near opposition. Numerical simulations reveal that double scattering between random irregular particles enhances negative polarization, and adding more particles further increases the polarization. Moreover, the interference mechanism is highly sensitive to the geometry of the scattering system.