Two-state wave packet for strong field-free molecular orientation

TL;DR

This paper demonstrates a method to achieve strong, field-free molecular orientation of carbonyl sulfide molecules using a combination of a long non-resonant laser pulse and a static electric field, resulting in significant transient orientation.

Contribution

The study introduces a novel two-state wave packet approach that enables strong, field-free molecular orientation by exploiting laser pulse edges to create coherent superpositions of rotational states.

Findings

Achieved a molecular orientation degree of 0.6, close to the theoretical maximum.

Demonstrated revivals of orientation after the laser pulse.

Showed potential for complete field-free orientation by switching off the static field.

Abstract

We demonstrate strong laser-field-free orientation of absolute-ground-state carbonyl sulfide molecules. The molecules are oriented by the combination of a 485-ps-long non-resonant laser pulse and a weak static electric field. The edges of the laser pulse create a coherent superposition of two rotational states resulting in revivals of strong transient molecular orientation after the laser pulse. The experimentally attained degree of orientation of 0.6 corresponds to the theoretical maximum for mixing of the two states. Switching off the dc field would provide the same orientation completely field-free.