Comparative study of the real-time optical trapping in the Rayleigh regime for continuous and pulsed lasers

TL;DR

This paper compares real-time optical trapping behaviors of continuous and pulsed lasers in the Rayleigh regime, highlighting differences in forces and stability, and introduces a model to predict trapping outcomes for various optical parameters.

Contribution

It presents a new model that predicts optical trapping stability and force differences between CW and femtosecond pulsed lasers in real-time scenarios.

Findings

Distinct differences in scattering and gradient forces between CW and pulsed lasers.

The model aids in predicting trap stability under various optical conditions.

Guidelines for solvent, probe, and laser parameter choices are provided.

Abstract

Simulating real-time scenarios to predict optical trapping behavior for continuous wave (CW) as well as femtosecond pulsed lasers is a challenging problem. This is especially so, because, for a tightly focused laser, one must also include optical Kerr effect as well as thermal nonlinearity. We show here the distinct differences between CW and femtosecond pulsed laser mediated optical trapping via their effect in scattering and gradient forces in the Rayleigh regime. In our newly developed model, it will also be easier to predict the stability of the trap in real optical trapping scenario as well as provide information regarding choice of solvents, probes, and optical parameters like laser type, power range, wavelength, etc. as may the cases be.