Tuneable quantum interference in a 3D integrated circuit

Understand

Integrated photonics promises solutions to questions of stability, complexity, and size in quantum optics.

• Advances in tunable and non-planar integrated platforms, such laser-inscribed photonics, continue to bring the realisation of quantum advantages in computation and metrology ever closer, perhaps most easily seen in multi-path interferometry.
• Here we demonstrate control of two-photon interference in a chip-scale 3D multi-path interferometer, showing a reduced periodicity and enhanced visibility compared to single photon measurements.
• Observed non-classical visibilities are widely tunable, and explained well by theoretical predictions based on classical measurements.