Superresolution microscopy of optical fields using tweezer-trapped single atoms

TL;DR

This paper demonstrates a superresolution optical field imaging technique using a single atom as a scanning probe, achieving 300 nm resolution beyond the diffraction limit by detecting fluorescence and ac Stark shifts.

Contribution

The authors develop a superresolution microscopy method with single trapped atoms to measure optical fields at subwavelength scales, surpassing traditional diffraction limits.

Findings

Achieved 300 nm spatial resolution in optical field imaging.

Successfully benchmarked with standing-wave Gaussian modes at 1560 nm and 781 nm.

Enhanced sensitivity by measuring forces exerted on the atom.

Abstract

We realize a scanning probe microscope using single trapped $^{87}$Rb atoms to measure optical fields with subwavelength spatial resolution. Our microscope operates by detecting fluorescence from a single atom driven by near-resonant light and determining the ac Stark shift of an atomic transition from other local optical fields via the change in the fluorescence rate. We benchmark the microscope by measuring two standing-wave Gaussian modes of a Fabry-P\'{e}rot resonator with optical wavelengths of 1560 nm and 781 nm. We attain a spatial resolution of 300 nm, which is superresolving compared to the limit set by the 780 nm wavelength of the detected light. Sensitivity to short length scale features is enhanced by adapting the sensor to characterize an optical field via the force it exerts on the atom.