Interferometric measurement of the refractive index and the thermo-optic coefficient of semiconductor-doped glasses

We report on an interferometric technique based on two-dimensional Fourier fringe analysis for measuring the refractive indices and the thermo-optic coefficients of semiconductor-doped glasses suitable for optical waveguide fabrication. The principle of the measurement method is discussed. The thermo-optic coefficients of semiconductor-doped Schott glass filters have been determined in the temperature range 25-85 °C.