All-Fiber Source and Sorter for Multimode Correlated Photons

Abstract

Photons occupying multiple spatial modes hold a great promise for implementing high-dimensional quantum communication. We use spontaneous four wave mixing to generate multimode photon pairs in a few mode fiber. We show the photons are correlated in the fiber mode basis using an all-fiber mode sorter. Our demonstration paves the way to realization of high-dimensional quantum protocols based on standard, commercially available, fibers in an all-fiber configuration.High-dimensional quantum bits hold great potential for quantum communication owing to their robustness to a realistic noisy environment [1,2]. Implementations based on encoding information in the transverse spatial modes of photons are especially promising due to the large Hilbert space they span [3,4]. In recent years, such implementations were successfully demonstrated in freespace [5,6]. Meanwhile, efforts for multimode fiber-based technologies are expected to achieve high-dimensional quantum communication without line of sight, based on the existing multimode fiber component and infrastructures [7,