Stimulated emission at the sum-frequency generation of a bichromatic field interacting with a three-level atom

Abstract

We have considered the stimulated emission that occurs at the sum-frequency generation of a bichromatic field interacting with a three-level atom in the cascade configuration. In the high intensity limit for both laser fields, the excitation spectra consist of an induced peak that occurs at the two-photon frequency and two sidebands that are peaked on both sides of the twophoton frequency. The intensities (heights) of the two sidebands take always positive values indicating that the process of induced absorption (attenuation) occurs at the corresponding frequencies. The intensity (height) of the induced peak at the two-photon frequency takes positive and negative values when both laser fields are at resonance and at off-resonance, respectively. Conditions are established under which the two-photon stimulated emission prevails, indicating that significant amplification occurs at the sum-frequency generation of the two laser fields.