Nuclear and electronic contributions to the third-order nonlinearity in different glasses

Using, a time resolved optical heterodyne Kerr effect experiment along with a Raman light diffusion experiment, we have measured the nuclear (non-instantaneous) and electronic (instantaneous) contributions to the nonlinear index of refraction in tellurite niobium-doped and silicate lead-doped glasses. The experimental set-up and the procedure used to measure the nuclear and electronic contribution are detailed. Our experimental results clearly indicate that the ratio between the instantaneous and the non-instantaneous contribution remain constant while the doping concentration or the temperature of the sample vary. These ratios are ∼5 and ∼10 in tellurite niobium-doped and silicate lead glasses, respectively.