We develop and optimize thin anti-reflection coatings (ARCs) for highly anisotropic materials in the mid infrared. Unlike conventional ARCs that assume nearly isotropic refractive indices, this work fully integrates the anisotropic nature of materials into the design process. We describe two designs of thin ARCs for highly anisotropic materials: a single form-birefringent layer, and a planar bilayer. We realized the planar bilayer ARC experimentally, demonstrating excellent mid-infrared anti-reflectance across over a broad range of angles for all polarizations.
@article{arxiv.2601.00558,
title = {Anti-reflection coatings for highly anisotropic materials in the mid infrared},
author = {Hongyan Mei and Jin-Woo Cho and Jae-Seon Yu and Huandong Chen and Shantanu Singh and Boyang Zhao and Jayakanth Ravichandran and Sun-Kyung Kim and Mikhail A. Kats},
journal= {arXiv preprint arXiv:2601.00558},
year = {2026}
}