• Special Issue
  • Underwater Wireless Optical Communication
  • 13 Article (s)
Editorial for Special Issue on Underwater Wireless Optical Communication
Jing Xu, Boon S. Ooi, and Gong-Ru Lin
Underwater wireless optical communication (UWOC) has gained increasing research interest worldwide from both academic and industrial communities, because of its high bandwidth, compact antennas, low latency, cost-effectiveness, and low power consumption. In the underwater world, the wireless optical links can be complementary to or even more competitive than its acoustic counterpart. Nevertheless, the hostile underwater environment sets up natural obstacles to most information carriers, including the lightwave, even at the right wavelength. Much attention has been recently paid to this interesting and challenging area, leading to impressive progresses. Hence, we launched this focus issue to discuss recent advances and progress in UWOC, and aimed to further stimulate future advancements in this emerging field.
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100001 (2019)
Hybrid LD and LED-based underwater optical communication: state-of-the-art, opportunities, challenges, and trends [Invited]
Xuan Huang, Fang Yang, and Jian Song
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100002 (2019)
Simulation and verification of pulsed laser beam propagation underwater using Markov chains [Invited]
Tianhua Zhou, Jian Ma, Tingting Lu, Guyu Hu, Tingwei Fan, Xiaopeng Zhu, Xiaolei Zhu, and Weibiao Chen
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100003 (2019)
50 Gb/s PAM4 underwater wireless optical communication systems across the water–air–water interface [Invited]
Chung-Yi Li, Hai-Han Lu, Yong-Cheng Huang, Qi-Ping Huang, Jing-Yan Xie, and Song-En Tsai
A 50 Gb/s four-level pulse amplitude modulation (PAM4) underwater wireless optical communication (UWOC) system across the water–air–water interface is demonstrated in practice. In practical scenarios, laser beam misalignment due to oceanic turbulence degrades performance in UWOC systems. With the adoption of a reflective spatial light modulator (SLM) with an electrical controller, not only can the laser be arbitrarily adjusted to attain a water–air–water scenario, but oceanic engineering problems can also be resolved to establish a reliable UWOC link. Brilliant bit error rate performance and clear PAM4 eye diagrams are attained by adopting a Keplerian beam expander and a reflective SLM with an electrical controller. This proposed PAM4 UWOC system presents a feasible state that outperforms existing UWOC systems due to its feature providing a high-speed water–air–water link.
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100004 (2019)
Performance characterization of two-way multi-hop underwater networks in turbulent channels [Invited]
Fangyuan Xing, Hongxi Yin, and Lianyou Jing
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100005 (2019)
Robust UOWC systems against bubble-induced impairments via transmit/receive diversities [Invited]
Lian-Kuan Chen, Yingjie Shao, and Rui Deng
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100006 (2019)
Recent achievements on underwater optical wireless communication [Invited]
Giulio Cossu
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100009 (2019)
Absorption and scattering effects of Maalox, chlorophyll, and sea salt on a micro-LED-based underwater wireless optical communication [Invited]
Pengfei Tian, Honglan Chen, Peiyao Wang, Xiaoyan Liu, Xinwei Chen, Gufan Zhou, Shuailong Zhang, Jie Lu, Pengjiang Qiu, Zeyuan Qian, Xiaolin Zhou, Zhilai Fang, Lirong Zheng, Ran Liu, and Xugao Cui
In this work, a blue gallium nitride (GaN) micro-light-emitting-diode (micro-LED)-based underwater wireless optical communication (UWOC) system was built, and UWOCs with varied Maalox, chlorophyll, and sea salt concentrations were studied. Data transmission performance of the UWOC and the influence of light attenuation were investigated systematically. Maximum data transmission rates at the distance of 2.3 m were 933, 800, 910, and 790 Mbps for experimental conditions with no impurity, 200.48 mg/m3 Maalox, 12.07 mg/m3 chlorophyll, and 5 kg/m3 sea salt, respectively, much higher than previously reported systems with commercial LEDs. It was found that increasing chlorophyll, Maalox, and sea salt concentrations in water resulted in an increase of light attenuation, which led to the performance degradation of the UWOC. Further analysis suggests two light attenuation mechanisms, e.g., absorption by chlorophyll and scattering by Maalox, are responsible for the decrease of maximum data rates and the increase of bit error rates. Based on the absorption and scattering models, excellent fitting to the experimental attenuation coefficient can be achieved, and light attenuation by absorption and scattering at different wavelengths was also investigated. We believe this work is instructive apply UWOC for practical applications.
Chinese Optics Letters
  • Publication Date: Oct. 10, 2019
  • Vol.17 Issue, 10 100010 (2019)

Underwater wireless optical communication (UWOC) has gained increasing research interest worldwide from both academic and industrial communities, because of its high bandwidth, compact antennas, low latency, cost-effectiveness, and low power consumption. In the underwater world, the wireless optical links can be complementary to or even more competitive than its acoustic counterpart. Nevertheless, the hostile underwater environment sets up natural obstacles to most information carriers, including the lightwave, even at the right wavelength. Much attention has been recently paid to this interesting and challenging area, leading to impressive progresses. Hence, we launched this focus issue to discuss recent advances and progress in UWOC, and aimed to further stimulate future advancements in this emerging field.