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Title: Scanning force sensing at micrometer distances from a conductive surface with nanospheres in an optical lattice
The center-of-mass motion of optically trapped dielectric nanoparticles in a vacuum is extremely well decoupled from its environment, making a powerful tool for measurements of feeble subattonewton forces. We demonstrate a method to trap and maneuver nanoparticles in an optical standing wave potential formed by retroreflecting a laser beam from a metallic mirror surface. We can reliably position a ∼ 170 n m diameter silica nanoparticle at distances of a few hundred nanometers to tens of micrometers 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 measure forces experienced by the particle while scanning the two-dimensional space parallel to the mirror surface, and we find no significant excess force noise in the vicinity of the surface. This method may enable 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 micrometer scales.  more » « less
Award ID(s):
2110524
NSF-PAR ID:
10347301
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Applied Optics
Volume:
61
Issue:
12
ISSN:
1559-128X
Page Range / eLocation ID:
3486
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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