TEMPERATURE-DEPENDENCE OF REFRACTIVE-INDEX OF SIO2 GLASS

The refractive index of silica glass has been measured in the UV and visible regions from -165.4 to 83.3-degrees-C. The wavelength dispersion at each temperature was fitted by the three-term Sellmeier equation. Analysis of the Sellmeier equation shows that the temperature dependence of the refractive index originates from the temperature shift of the resonance energy of the second term in the equation. The energy shift of the second term is in good agreement with the observed shift of the exciton peak at around 10.4 eV.