Time-resolved measurements of nonlinear refraction and two-photon absorption in glasses directly exhibit the effects of nuclear vibrational motion in addition to the electronic response. Time-domain observation of the Raman response of optical glasses allows us to determine the relative contributions of the electronic and nuclear mechanisms to the nonlinear response.

• Received 6 September 1996

DOI:https://doi.org/10.1103/PhysRevB.54.R12641