Vie 12.03.2010 11:30 hrs.

Sala de seminarios del segundo piso, edificio de Física Experimental

Seminario

Random (without cavity) laser with cold atoms: theoretical and experimental challenges

Dr. Vitalie Eremeev, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Santiago, Chile. Abstract:Because the subject proposed for the discussion is very particular and yet not well known, I will start with the introduction to the experimental and theoretical achievements in the field. In order to develop the theory for random laser with cold atoms at first step is presented the theoretical model discussed in [1] which explains the gain and the lasing processes with cold atoms confined in the cavity and the results are compared with the experimental data. In particular we have studied the Mollow gain mechanism for the cold atoms by considering the dressed-states formalism for the two-level atoms. Taking into account the method discussed in [2] we derived the semiclassical kinetic equations for quantum-mechanical expectation values of operators, which describe the coupled system of atoms and modes of the electromagnetic field. We studied the field dynamics for which found different regimes of the laser evolution, therefore the spectra for these regimes were calculated in order to understand the effects, which appear. Based on some ideas of this model but taking into account a different method for the quantization of the laser field [3] we build further the theory for random lasers. Concerning this problem the methodology and some prior results are presented while the study is still in progress.

References [1] W. Guerin, N. Mercadier, F. Michaud, D. Brivio, L.S. Froufe-Pérez, R. Carminati, V. Eremeev, A. Goetschy, S.E. Skipetrov, R. Kaiser, J. of Optics 12, 024002 (2010). [2] J. Zakrzewski, M. Lewenstein, Phys. Rev. A 45, 2057 (1992). [3] C. Viviescas and G. Hackenbroich, Phys. Rev. A 67, 013805 (2003).