Optimal field-free orientation of molecules with resonant tailored multicolor fields

Optimal field-free molecular orientation for a given number of populated states, achieved by using resonant laser pulses, is theoretically investigated for linear molecules. An optimal phase difference between the rotational states can be obtained, at full revival times, after the laser pulses have decayed and these phase conditions are analytically derived for multilevel systems ( J > 2). The dependence of the phase difference on the duration and absolute area of the laser pulses is analyzed. Finally, the optimal degree of molecular orientation can be obtained by adjusting the ratios of the peak amplitudes of the laser pulses, with the carrier-envelope phases or the delay time between the pulses fulfilling the phase conditions.