Coherent state truncation by conditional interferometry

Abstract

Based on a conditional interferometry proposed by Paris [Phys. Rev. A 62, 033813 (2000)], we prepare any chosen superposition of the vacuum, one-photon, and two-photon states, which is truncating from an input coherent state. Feeding two perfect single-photon states and a coherent state into the interferometry and employing two one-photon detections, the conditional state can be obtained in the signal port. Ideal and realistic features of the one-photon counting are taken into account together with the effect on the fidelity between the ideal state and the realistic case. The ideal state is just a particular case of the realistic state with the unit efficiency. We study the antibunching effect and Wigner function of the generated states. The results show that the generated states will exhibit their specular character.