Refractive‐Index Dispersion of Tellurite Glasses in the Region from 0.40 to 1.71 μm

The refractive index of binary tellurite glasses with various modifiers was measured down to the fifth decimal place in the wavelength range of 0.40–1.71 μm using the minimumedeviation method. An empirical equation based on the single‐oscillator Drude–Voigt dispersion equation. n d 2 = A·Nf λ 0 2 + B , is obtained, where n d is the refractive index at 0.5876 μm, N is the number of molecules in a unit volume, f is the average oscillator strength, λ 0 is the average resonance wavelength, and A and B are constants. The refractive index n d of tellurite glasses is substantially determined by the resonance wavelength at the ultraviolet region, which is affected by the main constituent, TeO 2 .