Ultrafast time-resolved polarization-dependent investigations on the dynamics in the Ã2B2 state of NO2 molecules

We perform time-resolved polarization-dependent study on ultrafast dynamics in the à 2 B 2 state of NO 2 . A linearly-polarized 400 nm femtosecond laser is used to resonantly pump NO 2 to its first excited state à 2 B 2 , and the time-dependent ionic yields produced via strong field ionization at 800 nm are measured under different laser polarizations. The yield ratios measured with the lasers perpendicular and parallel to each other first decrease then increase as the wave packet evolves on the excited state, with a minimum ratio at the delay time of 180 fs, which can be attributed to the evolution time in the à 2 B 2 state. The behavior of the time-resolved ionization in elliptically polarized laser field is also investigated and discussed. Our study indicates that the time-resolved polarization-dependent studies will shed some light on and pave the way to understand ultrafast dynamics in molecular excited states.