Using quantum light sources with broadband spectrum and wavelength division multiplexing (WDM) is an important way to realize an entanglement distribution network (EDN) in the optical-communication band. However, the user number of the EDN based on WDM would be limited by the spectrum of entangled photon pairs and bandwidth of the low loss transmission window of optical fibers. It is a barrier to realizing large-scale quantum networks by WDM.

In this work, we propose a photonic-reconfigurable entanglement distribution network (PR-EDN) based on space-division multiplexing (SDM). We demonstrate this idea by a silicon quantum photonic chip. The entanglement resources of the PR-EDN are generated by an array of SFWM quantum light sources and distributed to users by the controllable SDM on the chip, which is realized by on-chip quantum interferences. The method of SDM enables the scale of the EDN to break the limitation of the spectrum of wavelength, making the realization of a larger-scale EDN possible. In addition, we introduce the function of reconfigurable network topology by time-reverse HOM interference, which can control the network topologies on demand. Finally, we successfully verify the ability of reconfigurable network topology of the chip through coincidence counting experiments, Franson-type interference experiments and DO-QKD experiments with 12km fiber transmission.

This work has published on Photonics Research (DOI: 10.1364/PRJ.489139) at 28th Jun. 2023 and has been highlighted as an Editor's Pick. The first author of this paper is Ph.D. candidate Dongning Liu and the corresponding author of this paper is Prof. Wei Zhang.