Abstract: Sensing in scattering environments, such as fog, poses a serious challenge for infrared systems. Circular polarization is of increasing interest due to its potentially superior persistence in fog. Circular polarization imaging is one of the ways to avoid fog attenuation in infrared waves. Fog attenuation in infrared waves involves complicating interactions of scattering and absorption. The mechanism of circular polarization's increased persistence was theoretically expounded; it was proposed that circular polarization depolarized slowly due to the randomization of the photon's direction and the randomization of the helicity. Then, circularly polarized light was less affected by scattering. Optimal detection bands of target detection in fog were selected based on the mechanism of circular polarization's increased persistence and the atmospheric radiation spectrum. Optimal bands were selected which were 0.78-1.1 m, 1.48-1.56 m, 1.63-1.86 m, 2.03-2.18 m, 2.39-2.5 m in the SWIR and 3.6-4.15 m in the MWIR. However, the circular polarization imaging technique wasn't conducive to improve the fogging performance in the LWIR due to the optical absorption ratio increased. Finally, the characteristics and the development direction of circularly polarized imaging in complex atmosphere were summarized.