Eur. Phys. J. D (2014) 68: 108
https://doi.org/10.1140/epjd/e2014-40658-9

Regular Article

The physical mechanism of molecular alignment and orientation by a femtosecond two-color laser pulse

¹ Department of Physics, Henan Normal University, Xinxiang 453007, P.R. China
² College of Physics and Opto-electronics Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, P.R. China

^a e-mail: yuzhu.liu@gmail.com

Received: 24 October 2013
Received in final form: 9 December 2013
Published online: 7 May 2014

Abstract

The field-free molecular alignment and orientation by the femtosecond two-color laser pulse were studied theoretically. The time-dependent angular distributions of the molecular axis were presented and the physical mechanism of the field-free molecular alignment and orientation induced by a femtosecond two-color laser pulse was investigated. It was shown that the femtosecond two-color laser pulse can orient molecules due to the fact that it can change the parity of the molecular rotation wave function. It was also demonstrated that the dependence of field-free molecular orientation on the phase can provide a new way for evaluating the phase of a femtosecond two-color laser pulse. In addition, the effect of temperature on molecular alignment and orientation was discussed.