Nine-frequency-path quantum interferometry over 60 km of optical fiber

Abstract

The archetypal quantum interferometry experiment yields an interference pattern that results from the indistinguishability of two spatiotemporal paths available to a photon or to a pair of entangled photons. A fundamental challenge in quantum interferometry is to perform such experiments with a higher number of paths, and over large distances. In particular, the distribution of such highly entangled states in longhaul optical fibers is one of the core concepts behind quantum information networks. We demonstrate that using indistinguishable frequency paths instead of spatiotemporal ones allows for robust, high-dimensional quantum interferometry in optical fibers. In our system, twin-photons from an Einstein-Podolsky-Rosen (EPR) pair are offered up to 9 frequency paths after propagation in long-haul optical fibers, and we show that the multi-path quantum interference patterns can be faithfully restored after the photons travel a total distance of up to 60

High‐Dimensional Quantum Communication: Benefits, Progress, and Future Challenges

“…Indeed, noteworthy and fundamental results have been achieved by considering hybrid high-dimensional states. Some examples of hybrid qudits are spin-orbit states (combination of polarization and OAM) [58,[132][133][134], path-polarization states [135,136], polarization-time states [124] and frequency-path states [137].…”

Kerr optical frequency comb generation using whispering-gallery-mode resonators in the pulsed-pump regime

“…One of the most important application of our work belong to the realm of quantum optics. Indeed, quantum frequency combs are the ideal technological paradigm for the creation and manipulation of frequency bin states [35][36][37][38][39][40]. High-Q WGM resonators with pulsed pumping arose in recent years as ideal systems from that perspective as they have the potential to provide a chipscale platform for the next generation of quantum photonic systems, as it enables time bin protocols and drastically reduces the optical power needed to drive the resonators [41][42][43][44][45][46][47].…”

A characterization of quantum Kerr optical frequency combs

“…In this section, we aim at introducing a suitable representation of the quantum comb using the concept of frequency-bin states. [16][17][18][19] We assume the intrinsic loss of the cavity is much smaller than the through-port loss. As a consequence, out of all the photons exiting the microresonator, only few photons lose their partners inside the cavity and most of the them are photodetected with perfect pairwise correlation between the modes l and −l.…”