Superposed Coherent States improve fidelity of NOON states generated in post-selection

Abstract

Mixing the squeezed vacuum and coherent state in a beam-splitter generates NOON states of the electromagnetic field, but with fidelity less than unity. In this note it is shown that the output of the beam-splitter generates the NOON states with unit fidelity if superposed coherent states are used instead of the squeezed vacuum. Also, the post-selection probability of NOON states is shown to be higher.