Spectroscopy with squeezed fields

Summary form only given. We extend the analytical technique to the case of a fully quantized dressed-atom model with a detuned driving laser field and incorporate the cavity effect on the fluorescence spectrum. We find that the population trapping effect, predicted for the broadband squeezed vacuum case, may appear in a narrow-bandwidth squeezed vacuum only if there is nonzero squeezing at the Rabi sidebands. We show that this condition is readily achieved with a squeezed vacuum that is the output from a nondegenerate parametric oscillator, whereas for a squeezed vacuum that is the output from a degenerate parametric oscillator a squeezing bandwidth comparable to the Rabi frequency is required.