These years, we have witnessed great progress in manipulating radiative properties of thermal radiation, including angular, spectral, and polarized responses, via tailoring the light–matter interaction by taking advantages of designed nanostructures, metamaterials or metasurfaces, novel 2D materials, or even anisotropic materials. This chapter will review and give a detailed introduction of several manipulating mechanisms based on different types of materials, giving a comprehensive view of recent progress of radiative property engineering.

At micro/nanoscale, the general principles of the thermal radiation are failed to solve or explain the majority of radiative problems or phenomena. This chapter will first point out the limitations and reasons of the general principles of thermal radiation by introducing a typical example. Then, some basic concepts, including the role of energy carriers such as photons, electrons, and phonon will be introduced first, followed by the brief introduction of the corresponding governing equations and the influence mechanism in radiative properties. Next, we would like to give a fundamental framework and chart review from macro- to nanoscalethermal radiation, aiming to make the relation and difference between macro- and nanothermal radiation more distinct. Finally, the development of micro/nanoscale thermal radiation in the last decades will be summarized as well.