Three-photon bosonic coalescence in an integrated tritter

TL;DR

This paper reports the experimental observation of three-photon interference in an integrated three-port device, demonstrating bosonic coalescence and opening new avenues for quantum information applications.

Contribution

The authors experimentally realized a three-port integrated tritter using ultrafast laser-writing, enabling three-photon interference and bosonic coalescence in a compact, three-dimensional structure.

Findings

Observed three-photon bosonic coalescence in an integrated device

Demonstrated three-photon interference in a three-port tritter

Opened new possibilities for quantum information processing

Abstract

The main features of quantum mechanics reside in interference deriving from the superposition of different quantum objects. While current quantum optical technology enables two-photon interference both in bulk and integrated systems, simultaneous interference of more than two particles, leading to richer quantum phenomena, is still a challenging task. Here we report the experimental observation of three-photon interference in an integrated three-port directional coupler realized by ultrafast laser-writing. By exploiting the capability of this technique to produce three-dimensional structures, we realized and tested in the quantum regime a three-port beam splitter, namely a tritter, which allowed us to observe bosonic coalescence of three photons. These results open new important perspectives in many areas of quantum information, such as fundamental tests of quantum mechanics with increasing number of photons, quantum state engineering, quantum sensing and quantum simulation.