REFRACTIVE-INDEX CHANGES IN TI3+-DOPED GLASS

A photothermal detection technique has been used to measure changes in the index of refraction in Ti: phosphate-glass. The observed nonthermal change in the index of refraction after optical excitation is negligible for Ti: glass. This behavior, combined with earlier results obtained for Ti: sapphire, indicates that the nonthermal signal can be understood in terms of elastic relaxations around the Ti3+ ion in the different host materials. Specifically the amorphous glass structure is responsible for the smaller nonthermal signal in Ti: glass.