Observation of electromagnetically induced transparency in two-photon transitions of 39K2

Electromagnetically induced transparency has been observed in 39K2 two-photon transitions by fluorescence detection. The two-photon absorptions correspond to 23Πg←X1Σg+ transitions through A1Σu+∼b3Πu mixed intermediate enhancing levels, which are coincidentally on resonance with the excitation laser frequency. Laser intensity dependence of this effect has been studied and different detection schemes have been applied.