All-fiberized sorter for nondestructively splitting the orbital angular momentum modes

Abstract

Orbital angular momentum (OAM) mode sorter is crucial for various OAM (de)multiplexing applications. However, it is challenging to sort the OAM mode without destroying its helical phase. Here, an all-fiber non-destructive OAM mode sorter is proposed for splitting the high purity (>90%) OAM beam with specific topological charge, polarization state and wavelength. By controlling the asymmetrical microfiber coupling region, only the specific OAM mode satisfies the phase matching condition. The all-fibered OAM sorter is optimized to splitting the third order OAM mode with the maximum coupling efficiency 91.02% and the purity 94.71%. The Multiple modes sorter can be realized through the multistage cascaded structure. The proposed all-fiber OAM sort will be a prospective component to expand the OAM beam fiber system.