HANLE FLUORESCENCE-SPECTRA OF AN ATOM WITH A J(G)=0[--]J(E)=1 TRANSITION

We have investigated the two basic types of Hanle fluorescence spectra , distinguished by the direction of observation, from a V-type atom wi th a J(g) = 0<->J(e) = 1 transition excited by a linearly polarized la ser. In the absence of a magnetic field to lift the Zeeman degeneracy of the sublevels, the incoherent fluorescence spectrum G(X)(inc)(omega ) is dark for Rani frequencies, while the incoherent fluorescence spec trum G(Y)(inc)(omega) exhibits a single peak for small Rabi frequencie s and a Mollow-like triplet for large Rabi frequencies. However, if a magnetic field is applied, the incoherent spectra are composed, in gen eral, of five peaks. When omega(B) << Omega, the incoherent spectrum G (X)(Inc)(omega) has four peaks, while G(Y)(inc)(omega) has a Mellow-li ke triplet, and the integrated area (i.e., the fluorescence intensity) under the spectrum G(X)(inc)(omega) is much less than that of G(Y)(in c)(omega). When omega(B) >> Omega, both incoherent spectra have a two- peak structure similar to that of a two-level atom far off resonance, but the integrated area under the spectrum G(X)(inc)(omega) is much gr eater than that of G(Y)(inc)(omega). When omega(B) = Omega >> gamma, b oth spectra have a similar five-peak structure, and the same integrate d area. The results obtained are interpreted in the dressed atomic sta te representation. In the strong-field limit, the secular approximatio n is invoked, and analytical expressions of the resonance fluorescence spectra are derived which demonstrate the dependence of the peak heig hts and widths of the resonance fluorescence spectra on the intensitie s of the magnetic and linear polarized laser fields in a more transpar ent way.