Optimal squeezing, pure states, and amplification of squeezing in resonance fluorescence
Peng Zhou, Sanhita Swain · Physical Review A · 1999
It is shown that $100%$ squeezed output can be produced in the resonance fluorescence from a coherently driven two-level atom interacting with a squeezed vacuum. This is only possible for $N=1/8$ squeezed input, and is associated with a pure atomic state, i.e., a completely polarized state. The quadrature for which optimal squeezing occurs depends on the squeezing phase $\ensuremath{\Phi}$, the Rabi frequency $\ensuremath{\Omega}$, and the atomic detuning $\ensuremath{\Delta}$. Pure states are described for arbitrary $\ensuremath{\Phi}$, not just $\ensuremath{\Phi}=0$ or $\ensuremath{\pi}$ as in previous work. For small values of N, there may be a greater degree of squeezing in the output field than the input, i.e., we have squeezing amplification.