NONLINEAR ABSORPTION OF LASER-LIGHT IN BI2TEO5 SINGLE-CRYSTAL

Bi2TeO5 is a new nonlinear optical material that exhibits the photoref ractive effect including a long lived memory component. The nonlinear absorption properties of the material were investigated. With picoseco nd duration pulses, the two-photon absorption was found to be the pred ominant component of the nonlinear absorption. The two-photon absorpti on coefficient was measured to be 3.2-4.7 and 3.0-4.7 cm/GW for the [0 01] and [010] polarization directions, respectively. Contributions fro m free charge carrier absorption and excited state absorption were als o observed using time delayed laser pulses.