Europhys. Lett.
Volume 67, Number 1, July 2004
Page(s) 35 - 41
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 01 June 2004
Europhys. Lett., 67 (1) , pp. 35-41 (2004)
DOI: 10.1209/epl/i2003-10274-0

Observation of narrow fluorescence from doubly driven four-level atoms at room temperature

U. K. Khan, J. Sebastian, N. Kamaraju, A. Narayanan, R. Srinivasan and H. Ramachandran

Raman Research Institute - Sadashivnagar, Bangalore, 560 080 India

(Received 4 November 2003; accepted in final form 28 April 2004)

Unusually narrow spectral features are seen in fluorescence peaks from $\chem{{}^{85}Rb}$ atoms under the action of two driving laser fields that are in a three-dimensional molasses configuration. One of the lasers, L1, is held at a fixed detuning from the "cooling" transition, while the other, L2, is scanned across the "repumping" transitions. The fluorescence peaks are split into symmetric pairs, with the separation within a pair increasing with the detuning of the L1 laser. For large detunings, additional small peaks are seen. A simple model is proposed to explain these experimental observations.

42.50.Gy - Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption.
32.70.Jz - Line shapes, widths, and shifts.

© EDP Sciences 2004