Generating strong anti-bunching by interfering with coherent states

The second order correlation function is traditionally used to characterize the photon statistics and to distinguish between classical and quantum states of light. In this article we study a simple setup offering the possibility to generate strong anti-bunched light. This is achieved by mixing on a beam splitter a coherent state with a state with a non-negative Wigner function, such as squeezed states or weak Schrodinger cat states. We elucidate the interference mechanism generating such strong antibunching and relate it to unconventionnal photon blockade. We also detail how this effect can be used to measure weak squeezing.