Mueller matrix of laser scattering by a two-dimensional randomly rough surface

It is difficult to accurately identify material of a target surface only by scattering light intensity distribution, and polarization can provide more information. Randomly rough surfaces change the polarization state of incident light. Mueller matrix can describe the change of polarization during the propagation of light. In order to reveal the meaning of Mueller matrix elements, a large number of randomly rough surfaces are generated to simulate targets. Every rough surface is separated into a combination of large numbers of surface elements. Kirchhoff approximation is used to calculate local fields. A numerical integration method is used to calculate Mueller matrix. The effects of roughness, refractive index, and incident angle on Mueller matrix are calculated. Results show that roughness can change intensity distribution of scattered light. Complex refractive index can change polarization state of incident light and make the incident light with 45 degrees linear polarization appear circular polarization component. The effect of incident angle on intensity and polarization of scattered light is significant. m 34 and m 43 are key elements in Mueller matrix to identify material of target. Their influence on Stokes parameters of scattered light is studied. This research can provide a new method for laser detection device to identify target materials. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

Polarization provides more information for the identification of target surface materials. The study investigates the polarization characteristics of randomly rough surfaces and analyzes the effects of roughness, refractive index, and incident angle on polarization. Key elements m34 and m43 are identified for material identification.