An apparatus for in-vacuum loading of nanoparticles into an optical trap

Abstract

We describe the design, construction, and operation of an apparatus utilizing a piezoelectric transducer for in-vacuum loading of nanoparticles into an optical trap for use in levitated optomechanics experiments. In contrast to commonly used nebulizer-based trap-loading methods which generate aerosolized liquid droplets containing nanoparticles, the method produces dry aerosols of both spherical and high-aspect ratio particles ranging in size by approximately two orders of mangitude. The device has been shown to generate accelerations of order $10^7$ $g$, which is sufficient to overcome stiction forces between glass nanoparticles and a glass substrate for particles as small as $170$ nm diameter. Particles with sizes ranging from $170$ nm to $\sim 10$ $\mu$m have been successfully loaded into optical traps at pressures ranging from $1$ bar to $0.6$ mbar. We report the velocity distribution of the particles launched from the substrate and our results indicate promise for direct loading into ultra-high-vacuum with sufficient laser feedback cooling. This loading technique could be useful for the development of compact fieldable sensors based on optically levitated nanoparticles as well as matter-wave interference experiments with ultra-cold nano-objects which rely on multiple repeated free-fall measurements and thus require rapid trap re-loading in high vacuum conditions.

9 pages, 10 figures

References in corpus (7)

• Motional Quantum Ground State of a Levitated Nanoparticle from Room Temperature
• Millikelvin cooling of an optically trapped microsphere in vacuum
• Search for Millicharged Particles Using Optically Levitated Microspheres
• Attonewton force detection using microspheres in a dual-beam optical trap in high vacuum
• Optically levitated nanoparticle as a model system for stochastic bistable dynamics
• Limits on the abundance of millicharged particles bound to matter
• Optical trapping of high-aspect-ratio NaYF hexagonal prisms for kHz-MHz gravitational wave detectors

Cited by in corpus (3)

• Dry launching of silica nanoparticles in vacuum
• Optical Levitation of Arrays of Microspheres
• Modification of adhesion between microparticles and engineered silicon surfaces