Refractive Index Dispersion of Hexagonal Boron Nitride in the Visible and Near‐Infrared

Hexagonal boron nitride (h‐BN) is being widely utilized as a platform for optical and electrical devices exploiting two‐dimensional layered materials. By analyzing transmission spectra of h‐BN flakes transferred onto quartz plates with the transfer‐matrix method, the refractive index of h‐BN is determined in the wavelength range from 450 to 1200 nm. The transmission spectra are reproduced by applying the single oscillator model of n ( λ ) 2 = 1 + Aλ 2 /( λ 2 –λ 0 2 ) as the wavelength‐dependent refractive index. Averaging over the parameters from different samples, the parameters of λ 0 = 164.4 nm and A = 3.263 are obtained.