CONTRIBUTION OF PHASE GRATINGS IN PUMP-PROBE MEASUREMENTS OF INDUCED ABSORPTION.

Summary form only given. It is found that the effects of phase grating on the coherent contribution to pump-probe measurements of induced absorption must be considered whenever the real part of the nonlinear susceptibility is nonzero and the pulses display some degree of phase modulation. The contribution to the coherent signal associated with the induced phase grating will be antisymmetric as a function of delay time and will depend strongly on the exact form of the electric-field envelope.