Torsional optomechanical cooling of a nanofiber

TL;DR

This paper demonstrates cavity-less optomechanical cooling of a nanofiber's torsional modes by coupling light polarization to mechanical angular momentum, showing potential for simplified cooling setups.

Contribution

It introduces a novel method of cooling nanofiber torsional modes through birefringence-induced polarization coupling without using optical resonators.

Findings

Evidence of cooling in amplitude fluctuation distributions

Reduction in noise spectrum of torsional modes

Proof-of-principle cavity-less cooling demonstration

Abstract

We demonstrate the optomechanical cooling of a tapered optical nanofiber by coupling the polarization of light to the mechanical angular momentum of the system. The coupling is enabled by birefringence in the fiber and does not make use of an optical resonator. We find evidence for cooling in the distribution of thermally driven amplitude fluctuations and the noise spectrum of the torsional modes. Our proof-of-principle demonstration shows cavity-less cooling of the torsional degree of freedom of a macroscopically extended nanofiber.