Wavelength-by-Wavelength Temperature-Independent Thermal Radiation Utilizing an Insulator–Metal Transition
Jonathan King, Alireza Shahsafi, Zhen Zhang, Chenghao Wan, Yuzhe Xiao, Chengzi Huang, Yifei Sun, Patrick Roney, Shriram Ramanathan, Mikhail A. Kats
Abstract
Both the magnitude and spectrum of the blackbody radiation distribution change with temperature. Here, we designed the temperature-dependent spectral emissivity of a coating to counteract all the changes in the blackbody radiation distribution over a certain temperature range, enabled by the nonhysteretic insulator-to-metal phase transition of SmNiO3. At each wavelength within the long-wave infrared atmospheric-transparency window, the thermal radiance of our coating remains nearly constant over a temperature range of at least 20 °C. Our approach can conceal thermal gradients and transient temperature changes from infrared imaging systems, including those that discriminate by wavelength, such as multispectral and hyperspectral cameras.