Phase-controlled integrated photonic quantum circuits

TL;DR

This paper demonstrates a scalable, integrated photonic quantum circuit with external control, using UV-written waveguides and thermo-optic phase shifters, enabling stable and controllable quantum interference.

Contribution

It presents the first proof-of-principle of an externally-controlled integrated photonic quantum circuit with non-classical interference using UV-written waveguides.

Findings

Successful demonstration of non-classical interference in integrated circuits

Use of thermo-optic phase shifter for external control

Potential for scalable photonic quantum technologies

Abstract

Scalable photonic quantum technologies are based on multiple nested interferometers. To realize this architecture, integrated optical structures are needed to ensure stable, controllable, and repeatable operation. Here we show a key proof-of-principle demonstration of an externally-controlled photonic quantum circuit based upon UV-written waveguide technology. In particular, we present non-classical interference of photon pairs in a Mach-Zehnder interferometer constructed with X couplers in an integrated optical circuit with a thermo-optic phase shifter in one of the interferometer arms.