Measured transmittance of the reduced analog deposited on a MgF₂ substrate (blue curve) compared to the simulated spectrum of the Swanepoel method (pink curve) and Tauc-Lorentz model (green curve). The fitted parameters of the Tauc-Lorentz model are: A = 1.92 eV, C = 0.32 eV, Eo = 3.86 eV, E_g = 1.31 eV, and ε_∞ = 2.34. The Swanepoel method and Tauc–Lorentz model predict a film thickness of 1375 and 1351 nm respectively.