Polarization control of multi-photon absorption under intermediate femtosecond laser field

Cheng Wenjing^{1, ‡}, Liu Pei², Liang Guo¹, Wu Ping¹, Jia Tianqing², Sun Zhenrong², Zhang Shian^{2, §}

(color online) (a) The non-resonant two-photon and four-photon transition processes in the two energy level system. (b) The possible excitation pathways of non-resonant two-photon and on-resonant four-photon transition under the polarization modulated femtosecond laser field.