Comparison of Ultranarrow Fluorescence and Four-Wave Mixing in Electromagnetically Induced Transparency Windows

We simultaneously observe the probe transmission, four-wave mixing (FWM) and fluorescence signals under dressing effects in a four-level -type atomic system for the first time. The physical mechanisms of three types of signals are explored by changing the frequency detuning and power of incident laser beams. Especially, the ultranarrow fluorescence signals have been experimentally obtained due to ...