Eur. Phys. J. D (2021) 75: 181
https://doi.org/10.1140/epjd/s10053-021-00193-6

Regular Article - Optical Phenomena and Photonics

Evolution of the rotational quantum state in field-free molecular alignment and orientation

School of Science, Nantong University, 226019, Nantong, China

^b xsw@ntu.edu.cn

Received: 8 May 2021
Accepted: 8 June 2021
Published online: 23 June 2021

Abstract

We consider time-dependent evolution of the field-free molecular alignment and orientation for different rotational quantum states, induced by a single- and dual-color femtosecond laser pulses. We show that, compared to the evolutions of overall molecular alignment and orientation averaged by all rotational states, evolutions of each quantum state’s contribution present more complex temporal structure and provide richer dynamical evolving process of the molecules. Furthermore, we investigate the variation of the maximal degrees of the molecular alignment and orientation in different rotational quantum states. The results show that maximal degrees of both the molecular alignment and anti-alignment have the same change trend with the rotational state distribution, while for the molecular orientation consistency only exists in the variation of the difference between the maximal values of the positive and negative orientation. Correlation analysis shows it is independent of the molecular rotational temperature.