Optimal sideband-squeezing in the resonance fluorescence of a two-level atom

The quantum fluctuation spectra of phase quadratures of the fluorescent light from a coherently driven two-level atom damping in a common vacuum is investigated. We find that by optimally choosing the Rabi frequency of the driving field, detuning between the atom and the driving field, and phase of the local oscillator the strong sideband squeezing in the spectrum of the optimal phase quadrature can be created and the degree of squeezing in the sidebands can reach about 56%.