Molecular rotational constants measured with photoelectron ionization yield

We determined rotational constants of linear molecules by measuring the electron photoionization yields with the femtosecond pump-probe technique. By creating a rotational wave packet with linearly polarized pump pulse in N$_{2}$, O$_{2}$, CO$_{2}$, CO, and C$_{2}$H$_{2}$ molecules, we measured the temporal evolution of the photoelectron yield produced by the probe pulse with variable delay. The positions of the peaks and the rotational constants derived from the rotational revival periods of linear molecules are in good agreement with the literature values. This work was supported by the Robert A. Welch Foundation grant No. A1546 and the Qatar Foundation under the grant NPRP 5-994-1--172.