Nearly degenerate four-wave mixing with bichromatic laser fields in a Rb atomic system

We present an experimental study of cw nearly degenerate four-wave-mixing emission in a Doppler broadened Rb atomic system. With the fixed detuning of an intense pump laser for the Rb D₂ line, the nearly degenerate four-wave-mixing emission exhibits three peaks as a probe laser is scanned across the same Rb D₂ line. The observed three-peaked spectrum can be interpreted as the resonances in the energy structure of the dressed atomic states.