Nonlinear optical absorption properties of tellurium glasses containing different network modifiers

Linear- and nonlinear-optical absorption and carrier dynamic properties of binary tellurite glasses modified with different amount of WO₃, Nb₂O₅, and ZnO were investigated via UV–Vis spectrophotometer, open aperture Z-scan and pump-probe techniques. Glasses were synthesized using conventional melt quenching technique. The vitreous nature of the samples were confirmed by conducting XRD measurements. The studied glasses have got absorption spectra similar to that of the semiconductor materials and it is found that the absorption edges of the samples blue-shifted with the changing amount and the type of the network modifier. Nonlinear absorption measurements of samples were carried out using a laser source with 532 nm wavelength, 10 Hz repetition rate and 4 ns pulse duration. All of the samples showed nonlinear absorption behavior. The transmission pump-probe spectroscopy experiments were carried out to investigate the ultrafast carrier dynamics of studied glasses with the help of Ti:sapphire laser amplifier optical parametric amplifier system with 100 fs pulse duration. The experiments were established by excitation of glasses with 400 nm pump and 500 nm probe lights. The results of the measurements indicated that the two-photon absorption and two-photon assisted free carrier absorption mechanisms are responsible for the nonlinear optical processes. In the light of obtained linear and nonlinear optical results, it can be easily concluded that these glasses are very useful for LED, optical amplifier, data storage, and laser host applications (paper)