Laser Focusing of Atoms: A Particle Optics Approach

Published

September 1, 1991

Author(s)

Jabez J. McClelland, M Scheinfein

Abstract

The use of a TEM₀₁^*-mode laser beam has been proposed as a means of focusing an atomic beam to nanometer-scale spot diameters. We have analyzed the classibal trajectories of atoms through a TEM₀₁^*-mode laser beam using methods developed for particle optics. The differential equation that describes the properties of the first-order paraxial lens has exactly the same form as the bell-shaped magnetic Newtonian lens that was first analyzed by Glaser for the focusing of electrons in an electron-microscope objective. We calculate the first-order properties of the lens, obtaining cardinal elements that are valid over the entire operating range of the lens, including the thick and the immersion regimes. Contributions to the spot size are discussed, including four aberrations plus diffraction and atomic-beam-collimation effects. Explicit expressions are discussed for spherical, chromatic, spontaneous-emission, and dipole-flucuation aberrations are obtained. Examples are discussed for a sodium atomic beam, showing that subnanometer-diameter spots may be achieved with reasonable laser and atomic-beam parameters. Optimization of the lens is also discussed.

Citation

Journal of the Optical Society of America B-Optical Physics

Volume

8

Issue

9

Pub Type

Journals

Citation

McClelland, J. and Scheinfein, M. (1991), Laser Focusing of Atoms: A Particle Optics Approach, Journal of the Optical Society of America B-Optical Physics (Accessed April 20, 2024)