Transient Optical Susceptibility Induced by Nonperturbative Rotational Wave Packets

Abstract

Rotational wave packets formed in a gas of linear molecules can produce a time-dependent index of refraction that can be used as a phase modulator for an ultrafast pulse [1]. A collection of anisotropic molecules can be made to align along the polarization direction of an intense, linearly polarized laser pulse [1]–[4]. Although the molecules will quickly go out of alignment, the periodic rephasing of the wave packet causes the molecules to come back into alignment at regular intervals. During these so-called rotational revivals, the wave packet evolves through states where the molecules are both aligned and antialigned (i.e., perpendicular to) the polarization of the laser pulse.