Optomechanical Raman-Ratio Thermometry

TL;DR

This paper demonstrates a self-calibrating thermometry method based on Raman scattering asymmetry in cavity optomechanics, capable of measuring a wide temperature range from cryogenic to near room temperature.

Contribution

It introduces a Raman-ratio thermometry technique in cavity optomechanics that enables accurate temperature measurement of mechanical modes over a broad range.

Findings

Achieved temperature measurements down to a few vibrational quanta.

Demonstrated effective thermometry from cryogenic to near room temperature.

Validated the Raman-ratio method as a reliable, self-calibrating temperature sensor.

Abstract

The temperature dependence of the asymmetry between Stokes and anti-Stokes Raman scattering can be exploited for self-calibrating, optically-based thermometry. In the context of cavity optomechanics, we observe the cavity-enhanced scattering of light interacting with the standing-wave drumhead modes of a silicon nitride membrane mechanical resonator. The ratio of the amplitude of Stokes to anti-Stokes scattered light is used to measure temperatures of optically-cooled mechanical modes down to the level of a few vibrational quanta. We demonstrate that the Raman-ratio technique is able to measure the physical temperature of our device over a range extending from cryogenic temperatures to within an order of magnitude of room temperature.