Displacement calibration of optical tweezers with absolute gravitational acceleration

TL;DR

This paper introduces a novel calibration method for optical tweezers using free-falling particles in vacuum, leveraging gravitational acceleration as an absolute reference to enhance measurement accuracy.

Contribution

The paper presents an experimental calibration protocol for optical tweezers that improves accuracy and traceability by utilizing gravitational acceleration as an absolute reference.

Findings

Demonstrated calibration method achieves high certainty and traceability.

Improved the accuracy of displacement measurements in optical trapping.

Enhanced the potential for precision sensing with levitated particles.

Abstract

In recent years, levitated particles of optical traps in vacuum have shown enormous potential in precision sensor development and searching for new physics. The accuracy of the calibration relating the detected signal to absolute displacement of the trapped particle is a critical factor for absolute measurement performance. In this paper, we suggest and experimentally demonstrate a novel calibration method for optical tweezers based on free-falling particles in vacuum, where the gravitational acceleration is introduced as an absolute reference. Our work provides a calibration protocol with great certainty and traceability, which is significant in improving the accuracy of precision sensing based on optically levitated particles.