Abstract

New resonances are predicted in the interaction of a two-level system (TLS) with laser radiation. These resonances are related to the nonlinear coupling between the TLS and Brillouin enhanced acoustic waves driven by the laser radiation. Resonances in phase conjugation by four-wave mixing driven by stimulated Brillouin scattering (SBS) of laser radiation in fluids have been studied elsewhere.¹,² The coupling of such resonances to the TLS interaction with laser radiation influences the spectral behavior of the TLS. Such resonances appear in addition to the Rabi sidebands. The inclusion of these resonances should have important practical implications in processes that depend on accurate spectral behavior such as in the fields of laser spectroscopy, four-wave mixing, and phase conjugation. Here the new resonances are demonstrated for two mutually detuned counterpropagating laser beams interacting with a TLS at frequencies that may be detuned from the TLS spectral line center. The nonlinear Maxwell Bloch equations coupled to the acoustic wave equation are solved numerically. Damping due to viscosity is taken into account. Wave depletion is included and no perturbation theory approximations are assumed in the numerical solution of these equations.

© 1989 Optical Society of America