Measurement of the nonlinear optical response of optical fiber materials by use of spectrally resolved two-beam coupling

We present measurements of the femtosecond nonlinear response of fiber wave guide materials, obtained with spectrally resolved two-beam coupling. This simple but sensitive technique provides all the parameters that characteriz e the third-order nonlinear optical response, including the dynamics. Measu rements are made with nanojoule-energy pulses from a mode-locked Ti:sapphir e laser and a few millimeters of waveguide preform, without the need for dr awing fiber. (C) 1999 Optical Society of America.