Photon counting statistics of V-type three-level systems: The effects of the field fluctuations

We investigate the influence of the field fluctuations to the emission photons of V-type three-level systems. The emission intensity I and Mandel's Q parameter show stochastic resonance with respect to the pure dephasing constant γ_p. The amplitude fluctuation of the field causes these systems to lose their coherence. On the other hand, the amplitude fluctuation provides a new interference method for these systems. The quantum beats are shown in the orthogonal system.