Oscillations in the photon distribution of squeezed states are explained based on the interpretation of the generating function in terms of the generalized superposition of coherent fields and quantum noise.
We calculate the counting (multiplicity) distribution ${P}_{N}=〈N|\ensuremath{\rho}|N〉$ where $\ensuremath{\rho}$ is (i) the density matrix corresponding to a (pure) squeezed state and (ii) the density matrix of a superposition of squeezed states with thermal light. In the first case, we find that PN is an oscillating function of N. In the second case, this behavior, characteristic for squeezed states, disappears even for small amounts of noise.
In experiments, pulses of two-mode squeezed light were generated by an optical parametric amplifier. For certain ranges of parameters the joint photon number distribution of two-mode squeezed coherent states exhibits nonclassical oscillations. The nonclassical features were explained using the interference-in-phase-space concept in four-dimensional phase space. We investigate joint phase distribution of two- mode squeezed coherent states for presence of peaks and attempt to relate the peaks to the manifest oscillations in the joint photon number distribution.