Experimental demonstration of novel optical Brownian ratchet by controllable phase profile of light

TL;DR

This paper reports the experimental creation of a flexible optical Brownian ratchet using controllable phase profiles, enabling high-speed, large-step particle manipulation for studying nanoscale non-equilibrium dynamics.

Contribution

The authors demonstrate a novel optical Brownian ratchet controlled by holographic phase profiles, offering high flexibility and precise manipulation capabilities.

Findings

Average forward velocity of 28 μm/s

Step distance of about 42 μm

High control and flexibility in particle motion

Abstract

Brownian ratchet has emerged as a promising tool for understanding motion mechanism of molecules and proteins, and dynamically manipulating particles in non-equilibrium thermodynamics state. Here, we propose and experimentally demonstrate a new type of optical Brownian ratchets, which is generated by using controllable phase profiles in holographic optical trapping system. The potential energy profiles are dynamically switched in on-off mode, controlled by Labview software. Experimental results reveal that not only high speed but also large step distance can be easily achieved in Brownian ratchet, in which the average velocity of forward motion is about 28 {\mu}m/s and step distance is about 42 {\mu}m. More importantly, its motion path, step distance and velocity can be easily changed by manipulating its holograms, which exhibits high flexibility, easy control and excellent capability. This technique provides new opportunities for exploring non-equilibrium dynamics at the nanoscale level, and developing novel nanoparticle manipulation.