REFRACTIVE-INDEX DISPERSION OF TELLURITE GLASSES IN THE REGION FROM 0.40 TO 1.71 MU-M

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 mu m using the minimum-deviation method. An empirical equation based on the single-oscillator Drude-Voigt dispersion equation, n(d)(2) = A.Nf lambda(0)(2) + B, is obtained, where n(d) is the refractive index at 0.5876 mu m, N is the number of molecules in a unit volume, f is the average oscillator strength, lambda(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, TeO2.