An analytical model for the detection of levitated nanoparticles in optomechanics

TL;DR

This paper develops an analytical model for interferometric detection of levitated nanoparticles, enhancing understanding of system performance and explaining spectral artifacts, which is vital for precision optomechanics experiments.

Contribution

The paper introduces a new analytical model for nanoparticle detection in optomechanics, aligning theoretical predictions with experimental data.

Findings

Model explains spurious spectral frequencies

Achieves picometer-scale position sensitivity

Supports improved force and temperature measurements

Abstract

Interferometric position detection of levitated particles is crucial for the centre-of-mass (CM) motion cooling and manipulation of levitated particles. In combination with balanced detection and feedback cooling, this system has provided picometer scale position sensitivity, zeptonewton force detection, and sub-millikelvin CM temperatures. In this article, we develop an analytical model of this detection system and compare its performance with experimental results allowing us to explain the presence of spurious frequencies in the spectra.