Measurements of Atomic Lifetime and Natural Linewidth

We have exploited the well established technique of photon echoes to carry out a measurement of the excited state life time in room temperature Rb vapour to a precision of ~1%. This technique requires only a very simple set up and avoids the effects of radiation trapping and the necessity for a narrow laser line width, which are requirements for high precision determinations of radiative lifetime and natural line width.

We have also carried out a study of systematic effects associated with a measurement of the natural line width. We plan to undertake this experiment after the construction of a suitable narrow line width laser system.

Key Papers

Development of a Technique for Precise Determination of Atomic Lifetimes Based on Photon Echoes, H. C. Beica, A. Pouliot, P. Dowling, A. Carew, T. Vacheresse, G. Carlse, L. Marmet, A. Kumarakrishnan, Physical Review A, 101, 033408 (2020).

Measurement of Excited-State Lifetime Using Two-Pulse Photon Echoes in Rubidium Vapor, E. Rotberg, B. Barrett, S. Beattie, S. Chudasama, M. Weel, I. Chan, and A. Kumarakrishnan, Journal of the Optical Society of America B 24, 671 (2007).

Absorption Spectroscopy of Trapped Rubidium Atoms, S. Cauchi, A. Vorozcovs, M. Weel, S.Beattie, O. Gagnon, and A. Kumarakrishnan, Canadian Journal of Physics 82, 905 (2004).

Absorption spectrum from cold Rb atoms.

Photon echo reading

Photon echo intensity decay.