【摘要】 偏振特性是光场中除强度与光谱之外的又一维重要特性，在目标识别、军事侦察和红外目标探测等领域展现出广阔的应用前景。航天发动机、高速飞行器等人造物体通常温度可以达到几百摄氏度，因此具有高温自辐射特性。然而，高温情况下目标的红外偏振特性研究却相对较少，尤其是缺乏针对不同金属表面在较高温度下的偏振特性的深入探索。为了研究高温金属表面的辐射偏振特性，采用基于微面元理论的双向反射分布函数模型，结合镜面反射与漫反射特性，系统性地建立了基于金属自发辐射能量的偏振双向反射分布函数与红外辐射偏振度的数学模型。通过推导与计算，分析了不同表面粗糙度和温度条件下，金属对红外辐射线偏振度的影响规律。仿真结果表明，在相同温度下，金属表面的粗糙度越大，偏振度越低；相反，在相同粗糙度下，随着温度的升高，偏振度逐渐增加。同时利用LGC6122型长波红外相机与WP25M-IRC红外线栅偏振片，对金属铁和45号钢进行了在8～14μm波段内的目标自发辐射偏振热成像，获取了150、 200、 250、 300、 400和500℃下的长波红外线偏振度数据。针对实验观测而言，受普朗克黑体辐射定律影响，金属表面温度与其光谱积分偏振度呈正相关状态，温度越高，光谱积分偏振度越大。同时随着观测角度的增加，偏振度也逐渐增大，在70°～80°范围内达到峰值。该研究成果旨在提升红外目标检测等应用中热成像和光学传感技术的精度和其可靠性，并为未来进一步探索复杂环境下的红外探测技术提供参考。更多还原

【Abstract】 Polarization is a crucial dimension in the light field, alongside intensity and spectrum, and holds significant promise in applications such as target recognition, military reconnaissance, and infrared target detection. Artificial objects, such as spacecraft engines and high-speed aircraft, typically reach temperatures of several hundred degrees Celsius, exhibiting high-temperature self-radiation characteristics. However, there has been relatively little research on the infrared polarization characteristics of targets at high temperatures, particularly concerning the polarization properties of different metal surfaces under elevated temperatures. To investigate the polarization characteristics of high-temperature metal surfaces, a bidirectional reflection distribution function model based on microplane theory was systematically developed. This model incorporates both specular and diffuse reflection characteristics, establishing a mathematical framework for the BRDF of metal spontaneous radiation energy and the degree of polarization of infrared radiation. Through derivation and calculation, the influence of various surface roughness and temperature conditions on the polarization degree of infrared radiation from metals was analyzed. Simulation results indicate that at the same temperature, higher surface roughness of the metal leads to a lower polarization degree. Conversely, under the same roughness, the polarization degree increases with rising temperature. In parallel, thermal imaging of spontaneous radiation polarization was performed using an LGC6122 long-wave infrared camera and a WP25M-IRC infrared gate polarizer. The targets studied were iron and 45 steel, within the 8～14 μm wavelength range, at temperatures of 150, 200, 250, 300, 400, and 500 ℃. Experimental observations revealed that, influenced by Planck’s blackbody radiation law, the surface temperature of the metal is positively correlated with its spectral integral polarization degree: as the temperature increases, so does the spectral integral polarization degree. Additionally, the polarization degree gradually increases with the observation angle, peaking within the 70°to 80° range. The findings of this study aim to enhance the accuracy and reliability of thermal imaging and optical sensing technologies in infrared target detection and other related applications. Furthermore, they provide a reference for further exploration of infrared detection technologies in complex environments.更多还原