Integrated thermal management enabling 0.1 K uniformity in meter-scale blackbody radiation source over broad temperature ranges

Abstract Infrared radiation calibration is critical for quantifying remote sensing parameters. With the increase in optical aperture and sensitivity of infrared remote sensing imaging instruments, higher demands are placed on blackbody radiation sources. For example, to deliver uniform, high-quality radiation over square-meter-scale areas while operating reliably at cryogenic temperatures, and cover a wide temperature range. However, achieving this is challenging due to non-uniform cold input and external environmental factors. Here, we propose a method for cold energy input allocation, achieving uniform cooling input through loop-shaped dual-interface system designed to regulate thermal resistance along the heat transfer path. Additionally, we employ a multiple region heat differentiated input control method to accurately compensate for local power and counteract the influence of external heat flow. This approach reduces the temperature difference on the blackbody radiation surface by 98.0% compared to traditional methods. Based on the above methods, we have developed the latest generation of large area Blackbody infrared calibration system with 1.3×1.3 m 2 @ 60-360 K. Experiments show an emissivity of 0.992, temperature uniformity within ±0.098 K, corresponding radiance uncertainty at 0.65% for temperatures between 60 and 360 K. The techniques provide a general framework that can be adapted to improve both the thermal uniformity and emissivity performance of infrared radiation sources across various applications. Achieving thermal uniformity in meter-scale blackbody sources over broad temperature ranges is paramount for calibrating next-generation infrared sensors. Here, we present an integrated thermal management strategy. A loop-shaped dual-interface system ensures uniform cooling input by regulating path thermal resistance, while a multi-region differentiated heating control actively compensates for environmental loads. This synergistic approach enables our 1.3×1.3 m 2 blackbody to achieve unprecedented temperature uniformity of ±0.098 K@ 60-360 K and high emissivity of 0.992, advancing the precision of infrared remote sensing calibration. The work establishes a general framework for improving the thermal uniformity and emissivity performance of infrared radiation sources. Structural Overview of the Blackbody Infrared Calibration System. a Physical demonstration of the large-aperture blackbody. b External control system. c Design principle. d Structural decomposition diagram.