High-resolution hyperfine spectroscopy of excited states using electromagnetically induced transparencyA. Krishna, K. Pandey, A. Wasan and V. Natarajan
Department of Physics, Indian Institute of Science - Bangalore 560 012, India
received 7 June 2005; accepted in final form 18 August 2005
published online 14 September 2005
We use the phenomenon of electromagnetically induced transparency in a three-level atomic system for hyperfine spectroscopy of upper states that are not directly coupled to the ground state. The three levels form a ladder system: the probe laser couples the ground state to the lower excited state, while the control laser couples the two upper states. As the frequency of the control laser is scanned, the probe absorption shows transparency peaks whenever the control laser is resonant with a hyperfine level of the upper state. As an illustration of the technique, we measure hyperfine structure in the 7S1/2 states of 85Rb and 87Rb, and obtain an improvement of more than an order of magnitude over previous values.
32.10.Fn - Fine and hyperfine structure.
42.50.Gy - Effects of atomic coherence on propagation, absorption, and amplification of light; electromagnetically induced transparency and absorption.
42.50.-p - Quantum optics.
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