Multi-Photon Quantum Interference

Partha Pratim Sahu

Complex multi-photon quantum interference states are indispensable requisites for integrated quantum optic processing and quantum communication technologies. Here, two mode interference (TMI) coupler has been presented to demonstrate HOM model of multi-photons (N > 2) Quantum interference. The experiment of three and four photons quantum interference have been performed and coincidence rate of three and four photons quantum interference have been measured and quantum visibilities are obtained as ~ 0.783 ± 0.009 and ~ 0.85 ± 0.009 respectively at 3 dB TMI coupling length of 11.5 μm. High fabrication tolerance of quantum fidelity of TMI coupler has been achieved due to having less number of design parameters in comparison to directional coupler and multimode interference coupler. Our results pave the way to achieve multi-photons quantum entanglement in compact device.

Rainer Kaltenbaek, B. Blauensteiner, Markus Aspelmeyer +1 more

Konstantinos Poulios, Daniel Fry, Alberto Politi +4 more

Multi-mode interference (MMI) devices fabricated in silicon oxynitride (SiON) with a refractive index contrast of 2.4% provide a highly compact and stable platform for multi-photon non-classical interference. MMI devices can introduce which-path information for photons propagating in the multi-mode section which can result in degradation of this non-classical interference. We theoretically derive the visibility of quantum interference of two photons injected in a MMI device and predict near unity visibility for compact SiON devices. We complement the theoretical results by experimentally demonstrating visibilities of up to 97.7% in 2×2 MMI devices without the requirement of narrow-band photons.

Holger F. Hofmann, Yuki Kodama, Jonte R. Hance

Multi-photon interference can be observed using independently generated photons as input. In the most simple case, these photons meet up at a beam splitter, resulting in quantum interference between transmission and reflection of the photons. Here, we show that non-local multi-photon interference can be implemented by using a mode swap operation to generate entanglement between the photons detected in the outputs of two spatially separated interferometers. The spatial separation of the output photons makes this implementation of multi-photon interference particularly suitable for quantum protocols that distribute quantum information to different parties.

Rainer Kaltenbaek, B. Blauensteiner, Markus Aspelmeyer +2 more

David S. Simon, Gregg S. Jaeger, Alexander V. Sergienko