Free-space coherent optical communication demonstration using a 3D photonic integrated circuit device for orbital angular momentum multiplexing/demultiplexing

We show error-free 10GBd DQPSK data transmission performance using orbital angular momentum (OAM) modes that are multiplexed and demultiplexed by a low-loss, hybrid-integrated device based on a silica planar lightwave circuit (PLC) coupled to a 3-D photonic integrated circuit.