2009/06/29 by Andal Narayan, Narayan, Andal, Abheera Hazra +3
Physics and Astronomy · #FOS: Physical sciences #Laser-Matter Interactions and Applications #Quantum Physics (quant-ph) #Quantum optics and atomic interactions #Random lasers and scattering media #quant-ph
paper · pdf · doi:10.48550/arxiv.0906.5231
arxiv created 2009/06/29 · openalex publication_date 2009/06/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We experimentally study the absorption spectroscopy from a collection of gaseous 87 Rb atoms at room temperature irradiated with three fields. Two of these fields are in a pump probe saturation absorption configuration. The third field co-propagates with the pump field. The three fields address Zeeman degenerate transitions between hyperfine levels 5S1/2, F = 1 and 5P3/2, F = 0 and also between 5S1/2, F = 1 and 5P3/2, F =1 around the D2 line. We find a sub-natural absorption resonance in the counter-propagating probe field. The novel feature of this absorption is its abrupt onset in the vicinity of 5P3/2, F = 0, as the laser frequency is scanned from 5P3/2, F = 0 to 5P3/2, F =1. The experimental results are compared with the theory modeled after a four level system. There is a qualitative agreement between our theory and experiment. We find the threshold absorption to be a result of the off-resonant interaction of the strong field with nearby hyperfine levels.