Coherent control of vibrational and rotational molecular motions using double-pulse optical Kerr effect

The control of the coherent vibrational and rotational molecular motions in acetonitrile C2H3N was achieved by using the optically heterodyne-detected optical-Kerr-effect spectroscopy. A sequence of the two pump pulses with parallel and orthogonal polarizations was used for the non-resonant selective excitation of the molecular motions. The measurements showed that it is possible to control the molecular motions through the key parameters: the separation time, the relative intensities and polarization of the sequential pulses. The variation of the key parameters specifies the regimes of amplification and the suppression of the molecular responses. Two excitation scenarios with the amplification and suppression of the rotational responses were used as an example. The vibrational response was amplified in both cases.