Fig. 4: As2S3 in a family of high refractive index and birefringent materials.
From: Exploring van der Waals materials with high anisotropy: geometrical and optical approaches
a Refractive index and b the birefringence of van der Waals As2S3 and conventional photonic materials in their transparency windows. c Comparison of the maximum in-plane refractive index of van der Waals As2S3 in the transparency window with the established highly refractive materials
