Model for the thermo-optic coefficients of some standard optical glasses

Abstract The thermo-optic coefficients, d n d T , define the optical temperature properties of glasses. These coefficients are analyzed in a physically meaningful model for four standard reference glasses and vitreous silica. In this model, the optical band gaps, such as excitonic and isentropic, and the thermal expansion coefficient, contribute to the thermo-optic coefficients rather than the temperature coefficient of the electronic polarizability.