Real-Time Kalman Filter: Cooling of an Optically Levitated Nanoparticle

TL;DR

This paper demonstrates real-time Kalman filtering on an FPGA to achieve closed-loop feedback cooling of an optically levitated nanoparticle's motion, reducing its temperature from 300K to around 162mK.

Contribution

It introduces a real-time Kalman filter implementation on FPGA for feedback cooling of nanoparticles, achieving significant temperature reduction.

Findings

Achieved three orders of magnitude cooling of nanoparticle motion.

Successfully implemented real-time filtering and feedback control on FPGA.

Reduced nanoparticle temperature from 300K to 162 +/- 15mK.

Abstract

We demonstrate that a Kalman filter applied to estimate the position of an optically levitated nanoparticle, and operated in real-time within a Field Programmable Gate Array (FPGA), is sufficient to perform closed-loop parametric feedback cooling of the centre of mass motion to sub-Kelvin temperatures. The translational centre of mass motion along the optical axis of the trapped nanoparticle has been cooled by three orders of magnitude, from a temperature of 300K to a temperature of 162 +/- 15mK.