Advertisement

Recoil-Induced Resonances in Pump-Probe Spectroscopy

  • P. R. Berman
  • B. Dubetsky
  • J. Guo
Conference paper

Abstract

When a pump field and probe field simultaneously drive an electronic-state atomic transition, the probe field absorption spectrum can consist of an absorption peak centered near δ=−Δ and an amplification peak centered near δ′=Δ (δ′ is the frequency difference between the probe and pump fields and Δ is the pump field detuning from the atomic transition frequency) (see Fig. 1). This type of spectrum is seen in the limit that |Δ| »χ»72, where χ is the Rabi frequency associated with the pump field and γ 2 is the homogeneous width associated with the atomic transition. For atoms cooled below the recoil limit of laser cooling, the qualitative nature of the probe absorption spectrum can undergo a dramatic change. Provided that the recoil splitting ω k is larger than the homogeneous decay rate (as might occur in the case of a forbidden transition), the absorption and amplification features each split into an absorption — amplification doublet. In addition, new structure is found in the probe absorption spectrum near δ′=0; this structure consists of two absorption - amplification doublets. Both doublets can be resolved if ω k > γ 2. If ω k < γ 2, one of the doublets can be resolved provided that ω1, where Г1 is some effective ground state width in the problem. A spectrum in which all the recoil-induced structure is resolved is shown in Fig. 2. The positions, widths, and relative weights of all the components are readily predicted using a dressed-atom theory in which quantization of the center-of-mass momentum is included.1 Moreover, an analytical expression for the probe field spectrum can be obtained in a model calculation in which spontaneous decay to the lower level is neglected.1
Fig.1

Probe absorption spectrum, neglecting effects related to recoil. The gain component is not drawn to scale; in reality, it is smaller than the absorption component by a factor equal to the fourth power of the ratio of the pump Rabi frequency to the pump detuning.

Keywords

Probe Field Rabi Frequency Atomic Transition Qualitative Nature Laser Cool 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Reference

  1. 1.
    P. R. Berman, B. Dubetsky, and J. Guo, Recoil-induced resonances in pump-probe spectroscopy, Phys. Rev. A 51: 3947 (1995).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1996

Authors and Affiliations

  • P. R. Berman
    • 1
  • B. Dubetsky
    • 1
  • J. Guo
    • 2
  1. 1.Physics DepartmentUniversity of MichiganAnn ArborUSA
  2. 2.Joint Institute for Laboratory AstrophysicsUniversity of ColoradoBoulderUSA

Personalised recommendations