The dynamics of microparticle launching and loading into optical traps

Published

February 9, 2026

Author(s)

Kwanseob Park, Kiana Malmir, Glenn Holland, Martin Sohn, Thomas LeBrun

Abstract

Levitated optomechanics is opening new opportunities for quantum measurement in mesoscopic systems and for understanding the transition between quantum and classical mechanics. But loading microparticles into optical traps for measurements in vacuum remains an obstacle to the development of the field, in part because the process of launching particles so that they can be efficiently trapped remains poorly understood. We measure the dynamics of particle motion from vibrational excitation and launch to trapping in air. We demonstrate the direction of launch from a resonantly vibrating glass slide to be highly anisotropic and the typical escape velocity of tens of mm/s to be insensitive to the amplitude of vibrational excitation. Trajectories from the launch point to the trap are found to follow a roughly two-step process in air: rapid deceleration due to drag followed by drift into the trapping region that is accurately modeled by the Stokes-Einstein relation. These results illuminate the launch process in air to support development of controlled launching of microparticles in vacuum, including repeated loading of selected particles to enable reproducible measurement of launching conditions.

Citation

ACS Photonics

Pub Type

Journals

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Keywords

levitated optomechanics, optical trapping, optical tweezers, particle trajectory, stokes drag

Citation

Park, K. , Malmir, K. , Holland, G. , Sohn, M. and LeBrun, T. (2026), The dynamics of microparticle launching and loading into optical traps, ACS Photonics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957981 (Accessed September 30, 2026)

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