Optical Properties of Two-Level Media Excited by an Intense Polychromatic Field

摘要

Optical properties of two-level media excited by an intense polychromatic field with the mode interval Ω are studied by the method of a weak probing field. For the resonant case (the atomic transition frequency coincides with the pumping field frequency), absorption (dispersion) spectra are shown to possess resonances near detunings Ω_R~0 ± kΩ, where Ω_R~0 is the Rabi frequency of the central component of the excitation field, which is equal to zero for 2n-chromatic radiation. The magnitude of the resonances oscillates as the mode interval decreases. For very small Ω (Ω Γ), the system ceases to respond to the convergence of the components, and the absorption and dispersion spectra of the probing field are expressed in terms of approximation curves.