Field-free molecular orientation of ${}^{1}\phantom{\rule{-0.16em}{0ex}}\ensuremath{\Sigma}$ and ${}^{2}\phantom{\rule{-0.16em}{0ex}}\ensuremath{\Pi}$ molecules at high temperature

Field-free molecular orientation of $^{1} Σ$ and $^{2} Π$ molecules at high temperature

R. Tehini, Md Z. Hoque, O. Faucher, and D. Sugny

Phys. Rev. A 85, 043423 – Published 30 April 2012

Abstract

We analyze the control of field-free molecular orientation at high temperature by use of a two-color laser bipulse strategy proposed in Zhang et al. [Phys. Rev. A 83, 043410 (2011)]. A general study shows that there exist two types of linear molecules for which a different mechanism has to be used. For molecules with a large hyperpolarizability, a monochromatic laser pre-pulse is applied before the two-color laser pulse at a time close to the rotational period $T_{r}$ , while for molecules with a small hyperpolarizability, the optimal delay is found close to $T_{r} / 4$ or $3 T_{r} / 4$ . We extend this analysis to the case of a $^{2} Π$ molecule such as NO where a similar control strategy can be derived. These control processes are robust against temperature effects.