Abstract

Among coherent effects altering the material response in pump probe experiments, it has been recently demonstrated that in a time resolved interferometric experiment (where pump and probe laser pulses are fully degenerated, i.e same temporal and spatial frequencies (ω,k).⁽¹⁾), their signature introduces an oscillating term at 2ωτ where τ is the pump probe delay. This arises from new terms in the nonlinear polarization such as $E_{Pump}^2{E}_{probe}^2$, superimposed to the classical Kerr term $E_{probe}{E}_{Pump}{E}_{Pump}^{*}$. This particular behaviour must be analysed to exploit nonlinear responses from non resonant processes such as electronic.

© 1996 IEEE