Spatial evolutions of inversionless gain and lasing field intensity in an open V-type system with SGC

Abstract

This paper studies manly spatial evolution of gain without inversion (GWI) and the Rabi frequency E (intensity ɛp) of the probe field in an open V-type three-level inversionless lasing system with spontaneously generated coherence (SGC) for both cases with and without Doppler broadening. We found that: (1) Varying sizes of SGC strength (measured by angle θ), atomic exit rate (r0) and ratio (S) of the atomic injection rates has remarkable effect on spatial evolutions of GWI and E (ɛp). This effect in the case with Doppler broadening is similar to but weaker than that in the case without Doppler broadening. (2) Regardless of that Doppler broadening is present or not, GWI and E (ɛp) increase with increase of θ, r0 and S in certain value ranges of θ, r0 and S; in the case with SGC we can obtain GWI and E (ɛp) much larger than those in the case without SGC, while by choosing values of γ0 and S, in the open system we can obtain LWI gain and E (ɛp) much larger than those in the corresponding closed system. (3) The propagation distance in which GWI exists in the case with Doppler broadening is longer than that in the case without Doppler broadening; in the case without Doppler broadening, we can obtain larger GWI than that in the case with Doppler broadening; but in the case with Doppler broadening, we can obtain larger E (ɛp) than that in the case without Doppler broadening.