Narrowing And Dark Lines Of Three-level Atomic Resonance Fluorescence In A Single-mode Cavity

Resonance fluorescence is an important phenomenon in studying the non-classical effects of light and has always been an important topic in the field of quantum optics.The ultra-narrow line fluorescence effect in the fluorescence line plays an important role in some frontier basic physics research.In this paper,the resonance fluorescence spectra of a V-type three-level atom driven by a classical field in a single-mode cav-ity are studied.The cavity field is coupled with an energy level transition of the V-type thre.e-leve.l atom.The dressed fluorescence spectrum expression is obtained by dressing processing.It is found that the position of the fluorescence peak with the cavity coupled transition and the no-cavity coupled transition corresponds,indi-cating that the position of the spectral line is determined only by the strong driving field,independent of the weak cavity field.By observing the three-dimensional fluo-rescence spectrum,it was found that the narrowing of the spectral peaks below the threshold and above t.he threshold is different.We are concerned with the cavity field amplification effect above the threshold.The cavity field coupled to the transition has a significant effect on the fluorescence line of the no-cavity coupled transition.The slight difference is that the peak heights of the two fluorescence lines are dif-ferent.It can be seen that the narrowing of the spectrum occurs not only in the cavity coupling transition but also in the non-cavity coupling transition.Comparing the fluorescence spectra of V-type three-level atoms without cavity and cavity,by adjusting the parameters,the ultra-narrow line fluorescence effect can be seen when there is a cavity.