Bridging particle and wave sensitivity in a detector of configurable positive operator-valued measures

TL;DR

This paper introduces a tunable optical detector capable of performing a wide range of quantum measurements by combining weak-field homodyne techniques with photon-number-resolving detection, enabling both measurement and preparation of exotic quantum states.

Contribution

The work presents a novel, configurable POVM detector that bridges particle and wave sensitivities, allowing continuous tuning between different quantum measurement regimes.

Findings

Successfully reconstructed classical benchmark states using the detector.

Demonstrated continuous tuning of POVMs from Fock-state projectors to phase-dependent measurements.

Showcased the detector's capability for both quantum measurement and state preparation.

Abstract

We report an optical detector with tunable positive operator-valued measures (POVMs). The device is based on a combination of weak-field homodyne techniques and photon-number-resolving detection. The resulting POVMs can be continuously tuned from Fock-state projectors to a variety of phase-dependent quantum-state measurements by adjusting different system parameters such as local oscillator coupling, amplitude and phase, allowing thus not only detection but also preparation of exotic quantum states. Experimental tomographic reconstructions of classical benchmark states are presented as a demonstration of the detector capabilities.