Experimental study on the depolarization characteristics of scattered light from rough surfaces based on near-infrared polarized supercontinuum

This study explores the scattering characteristics of linearly polarized supercontinuum light when interacting with target objects, focusing on how changes in the polarization state relate to the surface structure of the objects. Polarization detection significantly enhances the ability to detect and identify targets, making it a vital area of research both domestically and internationally. In the classification of detection light sources, existing infrared polarization detection technologies are primarily divided into hyperspectral polarization detection techniques utilizing halogen lamps and single-wavelength polarization laser detection techniques. In contrast, employing infrared polarization supercontinuum lasers for direct target detection offers advantages such as superior beam quality and a broad detection wavelength range. We establish a measurement system to assess the polarization extinction ratio (PER) of near-infrared supercontinuum light and conduct experiments to evaluate the PER of the backscattered light from targets with varying surface roughness at different observation angles. The results reveal that increased surface roughness corresponds to a lower PER of the backscattered light and a higher degree of depolarization. Moreover, the PER initially increases and subsequently decreases with increasing angle of incidence, with the angle at which the PER reaches its maximum showing a correlation with the target's surface roughness. By investigating the interplay between surface roughness and observation angles on near-infrared PER, this study demonstrates the potential for effective target detection and identification.