Optical Properties of Biaxial van der Waals Crystals for Photonic Applications

Abstract

Recent advancements in nanophotonic devices rely on materials with high refractive index and large optical anisotropy. Among them, van der Waals (vdW) crystals have garnered considerable interest due to their record-value optical properties originating from their complex layered structure. Moreover, the number of vdW crystals increases rapidly every year, but their traditional optical characterization is time-consuming and cannot keep up with vdW crystals’ appearance. Here, we introduce an express method for the determination of vdW optical properties to resolve this issue by taking into account their anisotropy. Our approach relies on polarized micro-transmittance, which allows us to demonstrate the superior optical response of vdW crystals on the example of hBN and GeS₂. Hence, our developed technique offers a universal tool for the characterization of vdW materials’ optical properties for current and next-generation vdW-based photonic devices.