Light with even Fock states from interference of Kerr-squeezed light

We demonstrate the generation of nonclassical light by destructive interference of identical Kerr-squeezed states. Perfect pairwise cancellation of amplitudes that contribute to odd Fock states results in light with only even Fock states, independent of the strength of the nonlinearity. The observability of this effect is only limited by the quality of the interferometer. In the low nonlinearity limit, the even-only state resembles a squeezed vacuum state, yet the even-odd oscillations persist when the nonlinearity is strong. The effect is also robust against deviations from the optimum relative phase of the input Kerr-squeezed states.