'Light Storage' and other peculiarities of fast-light atomic medium

CAOUS, Swinburne University of Technology

Monday 17^th October 2005, 11.00AM, Seminar Room AR103, Graduate Research Centre.

All-optical information processing requires the use of photons as carriers of quantum information. Recently broad attention has been focussed on ‘light storage’ (LS), which is the preservation of the information carried by light for controlled later release. Such a possibility was suggested [1] and realized [2] in an atomic medium under conditions of electromagnetically induced transparency (EIT). Storage of light in such a medium was explained based on a model of a mixed light-matter excitation (dark state polariton), which propagates with very small group velocity ("slow-light" medium).

Our experimental observations of LS in rubidium vapour were achieved under conditions where EIT does not exist and the slow-light dark-state polariton model does not apply. Numerical modelling based on the optical Bloch equations reproduces the essential features of the experimental observations.

These results will contribute to a deeper understanding of light storage and retrieval using long-lived ground state atomic coherences. Furthermore, this could result in a reconsideration of the concept of the dark-state polariton and the development of new schemes and methods for more efficient control of light pulses in atomic media.

[1] M. Fleischhauer and M.D. Lukin, Phys. Rev. Lett. 84, 5094 (2000).
[2] D. F. Phillips, et al., Phys. Rev. Lett. 86, 783 (2001).

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