Precision Measurements of Temperature‐Dependent and Nonequilibrium Thermal Emitters

• Published in: Laser & photonics reviews Vol. 14; no. 8
• Main Authors: Xiao, Yuzhe, Wan, Chenghao, Shahsafi, Alireza, Salman, Jad, Yu, Zhaoning, Wambold, Raymond, Mei, Hongyan, Perez, Bryan E. Rubio, Derdeyn, William, Yao, Chunhui, Kats, Mikhail A.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.08.2020; Wiley Blackwell (John Wiley & Sons)
• Subjects: Camouflage; Electromagnetic radiation; Emitters; Energy harvesting; FTIR; infrared spectroscopy; Low temperature; Temperature dependence; Thermal emission; thermal‐emission measurement
• ISSN: 1863-8880; 1863-8899
• DOI: 10.1002/lpor.201900443

Thermal emission is the radiation of electromagnetic waves from hot objects. The promise of thermal‐emission engineering for applications in energy harvesting, radiative cooling, and thermal camouflage has recently led to renewed research interest in this topic. However, accurate and precise measurements of thermal emission in a laboratory setting can be challenging in part due to the presence of background emission from the surrounding environment and the measurement instrument itself. This problem is especially acute for thermal emitters that have unconventional temperature dependence, operate at low temperatures, or are out of equilibrium. In this paper, general procedures are described, recommended, and demonstrated for thermal‐emission measurements that can accommodate such unconventional thermal emitters. Thermal‐emission measurements can be challenging because of the presence of background emission from the surrounding environment and the instrument. This is especially the case for temperature‐dependent and nonequilibrium thermal emitters. This paper describes and demonstrates procedures for measurement and analysis that can accommodate such unconventional thermal emitters.