2022/10/03 by Mitradeep Sarkar, Sarkar, Mitradeep, Maxime Giteau +5 · 1 citation
Engineering · Materials Science · #FOS: Physical sciences #Optics (physics.optics) #Plasmonic and Surface Plasmon Research #Thermal Radiation and Cooling Technologies #Thermal properties of materials
paper · pdf · doi:10.48550/arxiv.2210.01026
openalex publication_date 2022/10/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Blackbody thermal emission is spatially diffuse. Achieving highly directional thermal emission typically requires nanostructuring the surface of the thermally emissive medium. The most common configuration is a subwavelength grating that scatters surface polaritonic modes from the near-field to the far-field and produces antenna-like lobes of thermal emission. This concept, however, is typically limited to a particular linear polarization, and requires sophisticated lithography. Here, we revisit the simple motif of a planar Salisbury screen. We show analytically how the interplay between the real and imaginary part of the dielectric permittivity of the emitter layer defines the directional characteristics of emission, which can range from diffuse to highly directional. We propose a realistic configuration and show that hexagonal Boron Nitride thin films can enable grating-like thermal emission lobes in a lithography-free platform.