Interference-enhanced optical force detection of weak light fields using a levitated nanoparticle

TL;DR

This paper introduces an interference-based technique to amplify optical forces on levitated nanoparticles, enabling highly sensitive detection of weak light fields and advancing optomechanical interaction studies at the single-photon level.

Contribution

It presents a novel interference method that significantly enhances optical force detection on levitated nanoparticles, improving sensitivity for weak light field measurements.

Findings

Achieved picowatt-level sensitivity in detecting weak light fields.

Demonstrated amplification of optical forces via interference with trapping beams.

Potential for ultrasensitive, nondestructive light field detection and single-photon optomechanics.

Abstract

Optically levitated nanoparticles in vacuum provide a highly sensitive platform for probing weak light-matter interactions. In this work, we present an interference-based method to amplify the optical force exerted by a weak field on a nanoscale particle trapped in an optical tweezer. By allowing the weak field to interfere with the strong trapping beam, we significantly enhance the optical force compared to the case without interference. This amplified optical force enables the detection of the weak field through the particle's motion, reaching picowatt-level sensitivity under moderate vacuum conditions. We further discuss the potential of this approach for developing an ultrasensitive, nondestructive detector of light fields and for exploring optomechanical interactions at the single-photon level.