Time-resolved absolute interferometric measurement of third-order nonlinear-optical susceptibilities

Abstract

A modified Mach–Zehnder interferometer has been built for measurement of nonlinear-optical susceptibilities in bulk materials. Both slow- and fast-intensity-dependent refractive-index changes can be measured in absolute value, with femtosecond time resolution, high sensitivity, and precision, by means of a new fringe-locking technique. Results on fast nonlinearities of CS₂ liquid and glasses are presented.