A computational tool to characterize particle tracking measurements in optical tweezers

TL;DR

This paper introduces a MATLAB-based computational tool integrated into the Optical Tweezers Toolbox that enables rapid theoretical characterization of particle tracking signals and shot-noise limits in optical tweezers experiments.

Contribution

It provides a versatile, easy-to-use computational method supporting arbitrary particle sizes and optical configurations for optical tweezers analysis.

Findings

Calculates particle tracking signals for various particles.

Determines shot-noise limit to position sensitivity.

Supports arbitrary optical configurations.

Abstract

Here we present a computational tool for optical tweezers which calculates the particle tracking signal measured with a quadrant detector and the shot-noise limit to position resolution. The tool is a piece of Matlab code which functions within the freely available Optical Tweezers Toolbox. It allows the measurements performed in most optical tweezers experiments to be theoretically characterized in a fast and easy manner. The code supports particles with arbitrary size, any optical fields and any combination of objective and condenser, and performs a full vector calculation of the relevant fields. Example calculations are presented which show the tracking signals for different particles, and the shot noise limit to position sensitivity as a function of the effective condenser NA.