为满足红外遥感器高精度定标和性能测试的要求,设计了一种高均匀性和宽辐射动态范围的红外积分球辐射源。积分球辐射源采用碳纤维石英电热管作为红外辐射介质,工作波段覆盖3~15 μm。利用积分球的空腔辐射理论和黑体辐射理论,提出子母镀金积分球串联的匀光方式,有效提高了红外积分球的均匀性。通过设计程控镀金光阑实现了动态范围的线性调节。建立了温度变化与辐射源辐亮度输出稳定性之间的关系,并确定了子母镀金积分球的温控精度。对红外积分球的特性进行分析与检测,结果表明:红外积分球出光口法线Φ200 mm范围内的面均匀性为98.87%,-15°~15°内竖直方向上的角度均匀性为99.69%,实现了动态范围的近线性可调功能,背景辐射小于同温度的黑体,非稳定性为0.16%,表现出较好的性能。红外积分球定标光源是传统黑体辐射源的有效补充,在红外遥感器的实验室光谱辐射定标中具有潜在的应用价值。

In this study, an infrared integrating sphere radiation source with high uniformity and wide dynamic range is designed to satisfy the high-precision calibration and performance testing requirements of infrared remote sensors. The designed radiatioin source adopts a carbon fiber quartz electric heating tube as the infrared radiation medium. The sphere's working band covers 3-15 μm. Based on the cavity radiation theory of integrating spheres and the blackbody radiation theory, the uniform-light mode of child and parent gold-plated integrating spheres is proposed. The proposed mode effectively improves the uniformity of the infrared integrating sphere. A programmable gold-plated aperture is also designed to realize the linear adjustment of the dynamic range. The relationship between temperature variation and radiance output stability and the temperature control accuracy of the child and parent gold-plated integrating spheres are determined. Characteristics of the infrared integrating sphere are analyzed and tested. Results reveal that the uniformity of the infrared integrating sphere in the area of Φ200 mm of the normal at the light exit is 98.87%, the angular uniformity from -15° to 15° in vertical plane is 99.69%, the dynamic range is nearly linearly adjustable, the background radiation is less than blackbody radiation at the same temperature, and the instability is 0.16%. These results demonstrate that the infrared integrating sphere possesses excellent performance. The infrared integrating sphere calibration source is an effective supplement to the traditional blackbody radiation source and has potential application value in the laboratory spectral radiometric calibration of infrared remote sensors.