Strong-field 2 photon absorption in cesium

We demonstrate the ultrafast coherent control of a nonlinear two-photon absorption in a dynamically shifted energy level structure. We use a spectrotemporal laser-pulse shaping that is programed to preserve the resonant absorption condition during the intense laser-field interaction. Experiments carried out in the strong-field regime of two-photon absorption in the ground state of atomic cesium reveal that the analytically obtained offset and curvature of a laser spectrum compensate the effect of both static and dynamic energy shifts of the given light-atom interaction.

Sangkyung Lee, Jongseok Lim, Jaewook Ahn, Vahe Hakobyan, and Stephane Guerin, "Strong-field two-level two-photon transition by phase shaping," Physical Review A 82, 023408 (August 2010). Media:SangkyungPRA2010.pdf