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 nontherm al change in the index of refraction after optical excitation is negli gible for Ti: glass. This behavior, combined with earlier results obta ined for Ti: sapphire, indicates that the nonthermal signal can be und erstood in terms of elastic relaxations around the Ti3+ ion in the dif ferent host materials. Specifically the amorphous glass structure is r esponsible for the smaller nonthermal signal in Ti: glass.