Abstract
In general, atmospheric turbulence can degrade the performance of free-space optical (FSO) communication systems by coupling light from one spatial mode to other modes. In this Letter, we experimentally demonstrate a 400 Gbit/s quadrature-phase-shift-keyed (QPSK) FSO mode-division-multiplexing (MDM) coherent communication link through emulated turbulence using four Laguerre Gaussian (LG) modes with different radial and azimuthal indices ($\mathbf{L}{\mathbf{G}_{10}}$, $\mathbf{L}{\mathbf{G}_{11}}$, $\mathbf{L}{\mathbf{G}_{ - 10}}$, and $\mathbf{L}{\mathbf{G}_{ - 11}}$). To mitigate turbulence-induced channel cross talk and power loss, we implement an adaptive optics (AO) system at the receiver end. A Gaussian beam at a slightly different wavelength is co-propagated with the data beams as the probe beam. We use a wavefront sensor (WFS) to measure the wavefront distortion of this probe beam, and this information is used to tune a spatial light modulator (SLM) to adaptively correct the four distorted data-beam wavefronts. Using this adaptive-optics approach, the power loss and cross talk are reduced by ∼10 and ∼18 dB, respectively. © 2023 Optical Society of America
© 2023 Optica Publishing Group
Full Article | PDF ArticleCorrections
Xinzhou Su, Zile Jiang, Yuxiang Duan, Huibin Zhou, Hao Song, Kai Pang, Cong Liu, Kaiheng Zou, Runzhou Zhang, Haoqian Song, Nanzhe Hu, Moshe Tur, and Alan E. Willner, "Adaptive-optics-based turbulence mitigation in a 400 Gbit/s free-space optical link by multiplexing Laguerre–Gaussian modes varying both radial and azimuthal spatial indices: publisher’s note," Opt. Lett. 49, 346-346 (2024)https://opg.optica.org/ol/abstract.cfm?uri=ol-49-2-346
18 December 2023: A typographical correction was made to the paper title.
More Like This
Kai Pang, Haoqian Song, Zhe Zhao, Runzhou Zhang, Hao Song, Guodong Xie, Long Li, Cong Liu, Jing Du, Andreas F. Molisch, Moshe Tur, and Alan E. Willner
Opt. Lett. 43(16) 3889-3892 (2018)
Guodong Xie, Yongxiong Ren, Yan Yan, Hao Huang, Nisar Ahmed, Long Li, Zhe Zhao, Changjing Bao, Moshe Tur, Solyman Ashrafi, and Alan E. Willner
Opt. Lett. 41(15) 3447-3450 (2016)
Huibin Zhou, Hao Song, Xinzhou Su, Yuxiang Duan, Kaiheng Zou, Runzhou Zhang, Moshe Tur, and Alan E. Willner
Opt. Lett. 49(5) 1209-1212 (2024)