Scanning force sensing at micrometer distances from a conductive surface with nanospheres in an optical lattice
Abstract
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 14, 2022
- Source ID
- 10.1364/ao.457148
Entities
People
- Andrew Geraci
- Apryl Witherspoon
- Cris Montoya
- Daniel Grass
- Eduardo Alejandro
- Nicolas Clarisse
- William Eom
Organizations
- Heising-Simons Foundation
- National Science Foundation Directorate for Mathematical & Physical Sciences
- Northwestern University
- Office of Naval Research
- University of Nevada, Reno