Sea fog is a particular kind of atmospheric aerosol that often poses hidden risks to ship navigation, ocean exploration, human productivity, and life. In light of the aforementioned issues, this research conducted a thorough investigation of the polarization transmission properties in a sea fog environment. We studied the physical characteristics of sea fog and established a polarized radiative transfer model based on RT3/PolRadtran (polarized radiative transfer) in a sea fog environment based on the theory of Mie scattering. The effects of wavelength, polarization state, sea fog concentration, and salt content on the polarization degree were simulated by using the polarization transport model. An indoor sea fog simulation device was designed and built. The simulation test results were compared with the experimental test results from many aspects, and the existing errors were analyzed so that they could be mutually verified for the overall trend. According to the modeling results, distinct polarization states of light exhibit evident depolarization as the sea fog concentration rises. Overall, circularly polarized light has superior polarization-maintaining properties compared to linearly polarized light under the same contrast settings. The penetrating impact of incoming light in the visible range improves with increasing wavelength, and the amount of salt in sea fog has some bearing on the degree of polarization.

During the daytime, the commonly used optical intensity imaging techniques for spacecraft detection usually lead to poor detection due to strong background noise. Since some materials with low reflectivity in the visible band have higher reflectivity in the near-infrared band and less sky background noise, this paper carries out a study of near-infrared polarization detection techniques. In this paper, firstly, the parameters in the pBRDF model of common materials are inverted and found to be improved compared with the literature, and secondly, a complex spherical projection is proposed to represent the polarization degree and polarization angle information of the sky background, and this projection has less aberration than the direct projection. Finally, from the above, the polarization detection contrast range and the original intensity contrast range are calculated, and it is found that the maximum of the former is higher than the latter in some angles.

Imaging detection is an important means to obtain target information. The traditional imaging detection technology mainly collects the intensity information and spectral information of the target to realize the classification of the target. In practical applications, due to the mixed scenario, it is difficult to meet the needs of target recognition. Compared with intensity detection, the method of polarization detection can effectively enhance the accuracy of ground object target recognition (such as the camouflage target). In this paper, the reflection mechanism of the target surface is studied from the microscopic point of view, and the polarization characteristic model is established to express the relationship between the polarization state of the reflected signal and the target surface parameters. The polarization characteristic test experiment is carried out, and the target surface parameters are retrieved using the experimental data. The results show that the degree of polarization (DOP) is closely related to the detection zenith angle and azimuth angle. The (DOP) of the target is the smallest in the direction of light source incidence and the largest in the direction of specular reflection. Different materials have different polarization characteristics. By comparing their DOP, target classification can be achieved.

With its benefits of efficiency and speed, the orthogonal experimental design method is currently often employed in many domains for multi-factor experimental design. In this study, the wind–wave–flow multifunctional experimental flume was used to replicate surge circumstances using the orthogonal technique in order to investigate the contributing factors and their interactions on the sea surface IR characteristics of underwater vehicles’ wakes. According to the correlation analysis, the height of the swell and the surface temperature difference of the wake had only a weak negative correlation, while the dive depth of the underwater vehicle and the surface temperature difference of the wake had a significant negative correlation (p = −0.833). It was tentatively concluded that the surface temperature differential of the wake was found to be more sensitive to dive depth than to swell height. An investigation of the impact of trailing IR features can use this finding as a pertinent reference.

The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed 《中国光学》的前身是1985年创办的《中国光学与应用光学文摘》，当时是国内光学领域唯一的检索刊物。2008年底《中国光学与应用光学文摘》转型更名为《中国光学与应用光学》期刊，刊载内容突破了文摘的限制，正式成为学术刊物。

The integration requirements of laser ranging, imaging, and communication functions in space target detection have placed higher demands on system performance. This paper takes a modularly designed integrated laser ranging, imaging, and communication system as an example and proposes a light source integration scheme based on fiber phased array beam splitting–coupling technology, effectively enhancing the system’s integration level and compactness. The system employs a Cassegrain optical system and beam splitting structure to achieve functional integration of laser communication, ranging, and polarization imaging. Ground experiments were conducted to evaluate the functional feasibility of the proposed integrated architecture. The visible light polarization imaging experiments at kilometer-level distances demonstrate that polarization-derived information can improve target–background separability under haze and low-contrast conditions. The UAV-based dynamic ranging experiment verifies that the system can acquire, track, and range a moving cooperative target under the tested field conditions, with the measured results being consistent with the designed meter-level ranging requirement. In addition, a 1 km coherent free-space laser communication experiment achieved 20 Gbps QPSK signal transmission with a bit error rate on the order of 10⁻⁷. These results provide experimental support and design references for integrated optoelectronic terminals used in space target observation, space debris monitoring, and related long-distance sensing and communication applications.