Coherent backscattering of light by saturated atoms

• Applicant: Professor Dr. Andreas Buchleitner
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2009 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 118966434

• Final Report Year: 2012

Final Report Abstract

Inelastic scattering processes induced by an intense laser field strongly reduce phase coherence of waves in coherent backscattering of light from cold atoms, yet do not destroy it altogether. So far, an accurate and intuitive understanding of why this is so has not been achieved. To bring insight into this problem, one needs to develop a theory based on a precise description of the responses of individual atoms to external driving, as well as of the exchange of inelastically scattered photons between the atoms. A standard theory of multiple scattering of intense laser light, based on the master equation approach, results in the exponential growth of the Hilbert space of the problem with the number of scatterers. We proposed a new, pump-probe, approach to coherent multiple scattering of intense laser light from cold atoms, wherein all calculations are restricted to the single-atom Hilbert space. This approach encapsulates the potential of the master equation, to accurately describe the nonlinear response of atoms to intense driving, and the potential of diagrammatic methods, to account for multiple scattering. So far, we have implemented this method to double scattering from two two-level atoms, as a proof of principle. A generalization to the generic case of many atomic scatterers, with arbitrary internal electronic structure, is currently in progress.

Publications

• Deducing residual self-interference of inelastic photons in coherent backscattering of intense laser light from two atoms, Opt. Commun. 282, 4095 (2009)
  V. Shatokhin
  
• Double scattering of intense laser light by two atoms. Chemical Physics 375, 150 (2010)
  V. Shatokhin, T. Geiger, T. Wellens, and A. Buchleitner
  
• Scattering laser light on cold atoms: Towards multiple scattering signals from single-atom responses, Phys. Rev. A 82, 013832 (2010)
  T. Wellens, T. Geiger, V. Shatokhin, and A. Buchleitner
  
• The pump-probe approach to coherent backscattering of intense laser light from cold atoms, Photonics and Nanostructures - Fundamentals and Applications 8, 244 (2010)
  T. Geiger, T. Wellens, V. Shatokhin, and A. Buchleitner