Using a Laguerre-Gaussian beam to trap and cool the rotational motion of a mirror

TL;DR

This paper proposes a theoretical method to trap and cool the rotational motion of a macroscopic mirror using Laguerre-Gaussian beams, potentially enabling quantum ground state preparation and sensitive torsional measurements.

Contribution

It introduces a novel approach to rotational cooling and trapping of macroscopic objects using orbital angular momentum transfer from Laguerre-Gaussian beams.

Findings

Theoretical demonstration of rotational trapping and cooling.

Potential to reach quantum ground state of rotation.

Possibility to cool vibrational modes simultaneously.

Abstract

We show theoretically that it is possible to trap and cool the rotational motion of a macroscopic mirror made of a perfectly reflecting spiral phase element using orbital angular momentum transfer from a Laguerre-Gaussian optical field. This technique offers a promising route to the placement of the rotor in its quantum mechanical ground state in the presence of thermal noise. It also opens up the possibility of simultaneously cooling a vibrational mode of the same mirror. Lastly, the proposed design may serve as a sensitive torsional balance in the quantum regime.