Differential interference-based measurement of 2D atomic crystal parameters

We present a differential interference-based method for precise measurement of 2D atomic crystal parameters. By analyzing optical differential phenomena near the pseudo-Brewster angle, we demonstrate that differential displacement exhibits distinct sensitivity to the parameters of 2D atomic crystals. Taking graphene as an example, we investigated the differential interference mechanism occurring at the air-graphene-prism interface and discovered that the parameters can be distinguished through the amplified displacement when the coherent interference intensity reaches its maximum. Based on these findings, we measured the number of graphene layers and characterized its optical conductivity <i>σ</i>₀=(5.91±0.07)×10^-5<i>Ω</i>^-1. This work not only enhances our understanding of the optical properties of 2D materials but also opens up new possibilities for their practical applications.