Controlling rotation in the molecular-frame with an optical centrifuge

TL;DR

This paper introduces a computational method to precisely control the rotation axes of asymmetric top molecules using an optical centrifuge, enabling advanced molecular alignment and orientation for imaging and scattering experiments.

Contribution

The study presents a novel approach for coherently controlling molecular rotation axes with an optical centrifuge, allowing arbitrary rotational wavepackets in asymmetric top molecules.

Findings

Successfully generated targeted rotational wavepackets in D₂S and 2H-imidazole.

Achieved three-dimensional molecular alignment along the laser's propagation direction.

Demonstrated potential for improved molecular imaging and scattering control.

Abstract

We computationally demonstrate a new method for coherently controlling the rotation-axis direction in asymmetric top molecules with an optical centrifuge. Appropriately chosen electric-field strengths and the centrifuge's acceleration rate allow to generate a nearly arbitrary rotational wavepacket. For D$_2$S and 2H-imidazole (C$_3$H$_4$N$_2$) we created wavepackets at large values of the rotational quantum number $J$ with the desired projections of the total angular momentum onto two of the molecules' principal axes of inertia. One application of the new method is three-dimensional alignment with a molecular axis aligned along the laser's wave vector, which is important for the three-dimensional imaging of molecules yet not accessible in standard approaches. The simultaneous orientation of the angular momentum in the laboratory frame and in the molecular frame could also be used in robust control of scattering experiments.