Suppression of plasma contribution in Femtosecond Degenerate Four-wave Mixing (fs-DFWM) at high intensity
Résumé
Femtosecond degenerate four-wave mixing (fs-DFWM) experiments in CO2 exhibit a strong background due to plasma produced at high intensity (½20 TW/cm2), when significant molecular alignment is likely to arise. This perturbing phenomenon renders the measurements of alignment very difficult. It is shown that the plasma contribution can be avoided by employing perpendicular polarizations for the two pump pulses. The effect is explained on the basis of the different diffraction angles between signals produced by molecular alignment and plasma.
Domaines
Optique [physics.optics]Origine | Fichiers produits par l'(les) auteur(s) |
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