title: Absorption imaging of a single atom.
abstract: Absorption imaging has played a key role in the advancement of science from van Leeuwenhoek's discovery of red blood cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in a vacuum. The optical properties of atoms are thoroughly understood, so a single atom is an ideal system for testing the limits of absorption imaging. A single atomic ion was confined in an RF Paul trap and the absorption imaged at near wavelength resolution with a phase Fresnel lens. The observed image contrast of 3.1 (3)% is the maximum theoretically allowed for the imaging resolution of our set-up. The absorption of photons by single atoms is of immediate interest for quantum information processing. Our results also point out new opportunities in imaging of light-sensitive samples both in the optical and X-ray regimes.
authors: Centre for Quantum Dynamics, Griffith University, Brisbane, Queensland 4111, Australia.
authors: Erik W
authors: EW
authors: Streed
authors: Andreas
authors: A
authors: Jechow
authors: Benjamin G
authors: BG
authors: Norton
authors: David
authors: D
authors: Kielpinski