Wavelength-Scale Imaging of Trapped Ions using a Phase Fresnel lens

TL;DR

This paper demonstrates near diffraction limited imaging of trapped ytterbium ions using a microfabricated phase Fresnel lens, achieving a resolution close to the transition wavelength, which advances ion imaging techniques.

Contribution

First demonstration of wavelength-scale imaging of trapped ions with a phase Fresnel lens achieving near diffraction limited resolution.

Findings

Achieved sub-440 nm (FWHM) imaging resolution.

Demonstrated imaging resolution on the order of the ion transition wavelength.

Validated the use of microfabricated phase Fresnel lenses for high-resolution ion imaging.

Abstract

A microfabricated phase Fresnel lens was used to image ytterbium ions trapped in a radio frequency Paul trap. The ions were laser cooled close to the Doppler limit on the 369.5 nm transition, reducing the ion motion so that each ion formed a near point source. By detecting the ion fluorescence on the same transition, near diffraction limited imaging with spot sizes of below 440 nm (FWHM) was achieved. This is the first demonstration of imaging trapped ions with a resolution on the order of the transition wavelength.