Physics

Nanotechnology

Optical power

Optical force

Laser

Biology

Optics

Dielectric

Magnet

Physical chemistry

Numerical aperture

Chemistry

Ecology

Materials science

Optical tweezers

Polarization (electrochemistry)

Trapping

Tweezers

Quantum mechanics

Levitation

Optoelectronics

Wavelength

Optica

Optical levitation of dielectric particles in vacuum is a powerful technique for precision measurements, testing fundamental physics, and quantum information science. Conventional optical tweezers require bulky optical components for trapping and detection. Here we design and fabricate an ultrathin dielectric metalens with a high numerical aperture of 0.88 at 1064 nm in vacuum. It consists of 500 nm-thick silicon nano-antennas, which are compatible with ultrahigh vacuum. We demonstrate optical levitation of nanoparticles in vacuum with a single metalens. The trapping frequency can be tuned by changing the laser power and polarization. We also transfer a levitated nanoparticle between two separated optical tweezers. Optical levitation with an ultrathin metalens in vacuum provides opportunities for a wide range of applications including on-chip sensing. Such metalenses will also be useful for trapping ultacold atoms and molecules.

On-chip optical levitation with a metalens in vacuum