TRANSIENT OSCILLATIONS IN NONDEGENERATE 2-BEAM COUPLING

The transient oscillations of the transmitted pump and probe intensiti es in nondegenerate two-beam coupling in media possessing a nonlinear index of refraction are described. These oscillations become evident w hen the pump-probe detuning or pump and probe intensities change fast compared with the response time of the material. A simple, accurate me thod for determining the response time of the nonlinearity from these oscillations, is derived, and it is used to measure the response time of pink ruby. This method also provides a measure of the nonlinear ind ex.