| Abstract: | It is shown that, in an open ladder-type atomic system with spontaneously generated coherence (SGC), regardless of the existence
of an incoherent pumping, a lasing without inversion (LWI) gain is always remarkable larger than in the system without SGC,
by adjusting the strength of SGC. Moreover, LWI gain in the system without incoherent pumping is much larger than that with
incoherent pumping, within some strength of SGC; while in the corresponding closed system with SGC, we can't obtain LWI gain
at any strength of SGC, if no incoherent pumping is applied. |
