We have time resolved, for the first time to our knowledge, the field-induced second-harmonic generation in lead lanthanum zirconate titanate (PLZT) thin films. Ultrafast nonlinear properties of 35/0/100 PLZT thin films are investigated with a Ti:sapphire laser, which generates 200-fs laser pulses. The PLZT responds with a rise time of 10 ps to a step-function electric field derived from a fast photoconductive coplanar waveguide structure switch. The dispersion characteristics of the measurements are addressed. (C) 1995 Optical Society of America