Journal of Physics B Atomic Molecular and Optical Physics
A strongly driven two-level atom revisited: Bloch - Siegert shift versus dynamic Stark splitting
Changjiang Wei, Andrew S. M. Windsor, Neil B. Manson
Abstract
We calculate a probe response of a homogeneously broadened two-level transition in the presence of a strong pump. The derivation is carried out for a generalized interaction Hamiltonian, which gives a uniform account of both the Bloch - Siegert shift and dynamic Stark splitting. It is shown that the Bloch - Siegert shift can be viewed as an extreme situation of the dynamic Stark splitting, commonly known as light shift in the literature. Finally using a perturbative approach an analytical expression for the Bloch - Siegert shift is obtained, which is compared with the previous results.