Effects of spontaneously generally coherence on probe response in an open lambda type system

Abstract

It is shown that in an open lambda type atomic system, the gain and dispersion of the probe field are quit sensitive to variation of spontaneously generally coherence (SGC). The value of the parameterp reflects whether SGC effect exists and the size of SGC effect. Under certain condition, whenp=0.002 electromagnetically induced transparency occurs; whenp≠0.002, lasing without inversion can be realized; whenp=0.95, high index of the refraction with zero absorption can be obtained.