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arXiv · 2103.03420

Scanning force sensing at $μ$m-distances from a conductive surface with nanospheres in an optical lattice

Cris Montoya·Eduardo Alejandro·William Eom·Daniel Grass·Nicolas Clarisse·Apryl Witherspoon·Andrew A. Geraci
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Abstract

The center-of-mass motion of optically trapped dielectric nanoparticles in vacuum is extremely well-decoupled from its environment, making a powerful tool for measurements of feeble sub-attonewton forces. We demonstrate a method to trap and manuever nanoparticles in an optical standing wave potential formed by retro-reflecting a laser beam from a metallic mirror surface. We can reliably position a $\sim 170$ nm diameter silica nanoparticle at distances of a few hundred nanometers to tens of microns from the surface of a gold-coated silicon mirror by transferring it from a single-beam tweezer trap into the standing wave potential. We can further scan the two dimensional space parallel to the mirror surface by using a piezo-driven mirror. This method enables three-dimensional scanning force sensing near surfaces using optically trapped nanoparticles, promising for high-sensitivity scanning force microscopy, tests of the Casimir effect, and tests of the gravitational inverse square law at micron scales.

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Cris Montoya, Eduardo Alejandro, William Eom, Daniel Grass, Nicolas Clarisse, Apryl Witherspoon, Andrew A. Geraci. 2021-03-05. Scanning force sensing at $μ$m-distances from a conductive surface with nanospheres in an optical lattice. https://doi.org/10.1364/ao.457148

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