Open AccessTurbulence heterodyne coherent mitigation of orbital angular momentum multiplexing in a free space optical link by auxiliary light
Author(s) -
Chao Yang,
Chao Xu,
Wenjun Ni,
Gui Yu,
Jing Hou,
Shaoping Chen
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.025612
Subject(s) - physics , optics , turbulence , free space optical communication , heterodyne (poetry) , angular momentum , distortion (music) , orbital angular momentum multiplexing , heterodyne detection , optical communication , light beam , gaussian beam , multiplexing , beam (structure) , orbital angular momentum of light , telecommunications , computer science , total angular momentum quantum number , acoustics , optoelectronics , laser , classical mechanics , amplifier , cmos , thermodynamics
A novel scheme is proposed to mitigate the atmospheric turbulence effect in free space optical (FSO) communication employing orbital angular momentum (OAM) multiplexing. In this scheme, the Gaussian beam is used as an auxiliary light with a common-path to obtain the distortion information caused by atmospheric turbulence. After turbulence, the heterodyne coherent detection technology is demonstrated to realize the turbulence mitigation. With the same turbulence distortion, the OAM beams and the Gaussian beam are respectively utilized as the signal light and the local oscillation light. Then the turbulence distortion is counteracted to a large extent. Meanwhile, a phase matching method is proposed to select the specific OAM mode. The discrimination between the neighboring OAM modes is obviously improved by detecting the output photocurrent. Moreover, two methods of beam size adjustment have been analyzed to achieve better performance for turbulence mitigation. Numerical results show that the system bit error rate (BER) can reach 10 -5 under strong turbulence in simulation situation.