AUTHOR=Xu Long , Tutunnikov Ilia , Prior Yehiam , Averbukh Ilya Sh. 

TITLE=Long-Lasting Orientation of Symmetric-Top Molecules Excited by Two-Color Femtosecond Pulses

JOURNAL=Frontiers in Physics

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2021.689635

DOI=10.3389/fphy.2021.689635

ISSN=2296-424X

ABSTRACT=<p>Impulsive orientation of symmetric-top molecules excited by two-color femtosecond pulses is considered. In addition to the well-known transient orientation appearing immediately after the pulse and then reemerging periodically due to quantum revivals, we report the phenomenon of <italic>field-free long-lasting</italic> orientation. Long-lasting means that the time averaged orientation remains non-zero until destroyed by other physical effects, e.g., intermolecular collisions. The effect is caused by the combined action of the field-polarizability and field-hyperpolarizability interactions. The dependence of degree of long-lasting orientation on temperature and pulse parameters is considered. The effect can be measured by means of second (or higher-order) harmonic generation, and may be used to control the deflection of molecules traveling through inhomogeneous electrostatic fields.</p>