Reconstruction of photon number conditioned states using phase randomized homodyne measurements

TL;DR

This paper demonstrates a method to reconstruct photon number conditioned states using phase randomized homodyne measurements, avoiding photon counting detectors, and revealing non-classical features through Wigner function negativity.

Contribution

It introduces a technique for state reconstruction without photon number discriminating detectors, enabling characterization of non-classical states in challenging experimental conditions.

Findings

Successfully reconstructed up to three photon subtracted squeezed vacuum states

Revealed regions of negativity in Wigner functions indicating non-classicality

Method applicable in systems where photon counting is difficult

Abstract

We experimentally demonstrate the reconstruction of a photon number conditioned state without using a photon number discriminating detector. By using only phase randomized homodyne measurements, we reconstruct up to the three photon subtracted squeezed vacuum state. The reconstructed Wigner functions of these states show regions of pronounced negativity, signifying the non-classical nature of the reconstructed states. The techniques presented allow for complete characterization of the role of a conditional measurement on an ensemble of states, and might prove useful in systems where photon counting still proves technically challenging.