Abstract

We find for infrared wavelengths that there are broad ranges of particle sizes and refractive indices that represent fog and rain, where circular polarization can persist to longer ranges than linear polarization. Using polarization tracking Monte Carlo simulations for varying particle size, wavelength, and refractive index, we show that, for specific scene parameters, circular polarization outperforms linear polarization in maintaining the illuminating polarization state for large optical depths. This enhancement with circular polarization can be exploited to improve range and target detection in obscurant environments that are important in many critical sensing applications. Initially, researchers employed polarization-discriminating schemes, often using linearly polarized active illumination, to further distinguish target signals from the background noise. More recently, researchers have investigated circular polarization as a means to separate signal from noise even more. Specifically, we quantify both linearly and circularly polarized active illumination and show here that circular polarization persists better than linear for radiation fog in the short-wave infrared, for advection fog in the short-wave and long-wave infrared, and large particle sizes of Sahara dust around the 4 μm wavelength. Conversely, we quantify where linear polarization persists better than circular polarization for some limited particle sizes of radiation fog in the long-wave infrared, small particle sizes of Sahara dust for wavelengths of 9–10.5 μm, and large particle sizes of Sahara dust through the 8–11 μm wavelength range in the long-wave infrared.

© 2015 Optical Society of America

Superior signal persistence of circularly polarized light in polydisperse, real-world fog environments

J. D. van der Laan, J. B. Wright, S. A. Kemme, and D. A. Scrymgeour
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Visible–IR transmission enhancement through fog using circularly polarized light

Xiangwei Zeng, Jinkui Chu, Wenda Cao, Weidong Kang, and Ran Zhang
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Polarization enhancement of linearly polarized light through foggy environments at UV–NIR wavelengths

Xiangwei Zeng, Xueye Chen, Yahong Li, and Qiao Xiangnan
Appl. Opt. 60(26) 8103-8108 (2021)

Effects of collection geometry variations on linear and circular polarization persistence in both isotropic-scattering and forward-scattering environments

John D. van der Laan, Jeremy B. Wright, David A. Scrymgeour, Shanalyn A. Kemme, and Eustace L. Dereniak
Appl. Opt. 55(32) 9042-9048 (2016)

Evolution of circular and linear polarization in scattering environments

John D. van der Laan, Jeremy B. Wright, David A. Scrymgeour, Shanalyn A. Kemme, and Eustace L. Dereniak
Opt. Express 23(25) 31874-31888 (2015)