Femtosecond non-resonant optical nonlinearity of silver chloride nanocrystal doped niobic tellurite glass

摘要

Silver chloride (AgCl) nanocrystal doped niobic tellurite glass (80TeO(2)-20Nb(2)O(5)) was synthesized by melting-quenching and heat treatment technique, and its non-resonant ultrafast nonlinear optical properties were investigated. Longer thermal treatment time can enlarge the AgCl nanocrystal grain size and increase the AgCl nanocrystal density, and it further results in forming more defect centres and stronger lattice deformation at the interface of the AgCl nanocrystal, and so gives rise to the band gap redshift and broadens the absorption band-width. The band gap redshift enhances two-photon absorption and results in a decrease in the optical limiting threshold. The third order nonlinear susceptibility chi((3)) can be enhanced for the transient polarization of the trapped electrons on the surface of the AgCl nanocrystal.