Bichromatic Laser Cooling in a Three-Level System

Authors

R. Gupta, State University of New York at Stony Brook
C. Xie, State University of New York at Stony Brook
S. Padua, State University of New York at Stony Brook
Herman Batelaan, University of Nebraska-LincolnFollow
Harold Metcalf, SUNY Stony BrookFollow

Date of this Version

1993

Document Type

Article

Citation

Physical Review Letters Volume 71, Number 19 November 1993

Comments

Copyright 1993 The American Physical Society. Used by Permission.

Abstract

We report a 1D study of optical forces on atoms in a two-frequency laser field. The light couples two ground state hyperfine structure levels to a common excited state of ⁸⁵Rb, thus forming a Δ system. We observe a new type of sub-Doppler cooling with blue-tuned light that uses neither polarization gradients nor magnetic fields, efficient heating with red tuning, and the spatial phase dependence of these. We observed deflection from a rectified dipole force and determined its velocity dependence and capture range. We report velocity selective resonances associated with Raman transitions. A simplified semiclassical calculation agrees qualitatively with our measurements.