Optimal squeezing, pure states, and amplification of squeezing in resonance fluorescence

It is shown that 100% squeezed output can be produced in the resonance fluo rescence from a coherently driven two-level atom interacting with a squeeze d vacuum. This is only possible for N = 1/8 squeezed input, and is associat ed with a pure atomic state, i.e., a completely polarized state. The quadra ture for which optimal squeezing occurs depends on the squeezing phase Phi, the Rabi frequency Omega, and the atomic detuning Delta. Pure states are d escribed for arbitrary Phi, not just Phi = 0 or pi as in previous work. For small values of N, there may be a greater degree of squeezing in the outpu t field than the input, i.e., we have squeezing amplification. [S1050-2947( 99)04705-8].