Orbital angular momentum(OAM)-carrying beams have received extensive attention due to their high-dimensional characteristics in the context of free-space optical communication.However,accurate OAM mode recognition sti...Orbital angular momentum(OAM)-carrying beams have received extensive attention due to their high-dimensional characteristics in the context of free-space optical communication.However,accurate OAM mode recognition still suffers from reference misalignment of lateral displacement,beam waist size,and initial phase.Here we propose a deep-learning method to exquisitely recognize OAM modes under misalignment by using an alignment-free fractal multipoint interferometer.Our experiments achieve 98.35% recognizing accuracy when strong misalignment is added to hyperfine OAM modes whose Bures distance is 0.01.The maximum lateral displacement we added with respect to the perfectly on-axis beam is about±0.5 beam waist size.This work offers a superstable proposal for OAM mode recognition in the application of free-space optical communication and allows an increase of the communication capacity.展开更多
基金National Natural Science Foundation of China(11534008,91736104)Ministry of Science and Technology of the People's Republic of China(2016YFA0301404)Fundamental Research Funds for the Central Universities.
文摘Orbital angular momentum(OAM)-carrying beams have received extensive attention due to their high-dimensional characteristics in the context of free-space optical communication.However,accurate OAM mode recognition still suffers from reference misalignment of lateral displacement,beam waist size,and initial phase.Here we propose a deep-learning method to exquisitely recognize OAM modes under misalignment by using an alignment-free fractal multipoint interferometer.Our experiments achieve 98.35% recognizing accuracy when strong misalignment is added to hyperfine OAM modes whose Bures distance is 0.01.The maximum lateral displacement we added with respect to the perfectly on-axis beam is about±0.5 beam waist size.This work offers a superstable proposal for OAM mode recognition in the application of free-space optical communication and allows an increase of the communication capacity.
