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arXiv · 2507.17591

Using optical tweezers to simultaneously trap, charge and measure the charge of a microparticle in air

Andrea Stoellner·Isaac C. D. Lenton·Artem G. Volosniev·James Millen·Renjiro Shibuya·Hisao Ishii·Dmytro Rak·Zhanybek Alpichshev·Gregory David·Ruth Signorell·Caroline Muller·Scott Waitukaitis
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Abstract

Optical tweezers are widely used as a highly sensitive tool to measure forces on micron-scale particles. One such application is the measurement of the electric charge of a particle, which can be done with high precision in liquids, air, or vacuum. We experimentally investigate how the trapping laser itself can electrically charge such a particle, in our case a $\sim 1\,\mathrm{\mu m\;SiO_2}$ sphere in air. We model the charging mechanism as a two-photon process which reproduces the experimental data with high fidelity.

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Andrea Stoellner, Isaac C. D. Lenton, Artem G. Volosniev, James Millen, Renjiro Shibuya, Hisao Ishii, Dmytro Rak, Zhanybek Alpichshev, Gregory David, Ruth Signorell, Caroline Muller, Scott Waitukaitis. 2025-07-23. Using optical tweezers to simultaneously trap, charge and measure the charge of a microparticle in air. https://doi.org/10.1103/5xd9-4tjj

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