Author Affiliations
Abstract
1 Centre for Optical and Electromagnetic Research, National Engineering Research Center for Optical Instruments, Zhejiang University, Hangzhou 310058, China
2 Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
In this paper, recent advances in underwater wireless optical communication (UWOC) are reviewed for both LED- and LD-based systems, mainly from a perspective of advanced modulation formats. Volterra series-based nonlinear equalizers, which can effectively counteract the nonlinear impairments induced by the UWOC system components, are discussed and experimentally demonstrated. Both the effectiveness and robustness of the proposed Volterra nonlinear equalizer in UWOC systems under different water turbidities are validated. To further approach the Shannon capacity limit of the UWOC system, the probabilistic constellation shaping technique is introduced, which can overcome the inherent gap between a conventional regular quadrature amplitude modulation (QAM) format and the Shannon capacity of the channel. The experimental results have shown a significant system capacity improvement compared to the cases using a regular QAM.
060.2605 Free-space optical communication 060.4080 Modulation 140.7300 Visible lasers 010.4450 Oceanic optics Chinese Optics Letters
2019, 17(10): 100012
本文在分析相干光激励下多模光纤束的辐射特性的基础上,提出了以多模光纤束产生的激光散斑场作为物体照明光波和参考光波的散斑场全息照相理论和实验技术,给出了与理论相一致的实验结果,同时也讨论了散斑全息照相在全息干涉计量中的应用.
振幅全息图 多模光纤