Abstract

In this paper, an optical pulse amplitude modulation with 4 levels (PAM-4) using a fiber combiner is proposed to enhance the data rate of a field-programmable gate-array-based long-distance real-time underwater wireless optical communication system. Two on–off keying signals with different amplitudes are used to modulate two pigtailed laser diodes, respectively, and the generated optical signals are superimposed into optical PAM-4 signals by a fiber combiner. The optical PAM-4 scheme can effectively alleviate the nonlinearity, although it reduces the peak-to-peak value of the emitting optical power by 25%. A real-time data rate of 187.5 Mbit/s is achieved by using the optical PAM-4 with a transmission distance of 50 m. The data rate is increased by about 25% compared with the conventional electrical PAM-4 in the same condition.

© 2023 Chinese Laser Press

10-m 9.51-Gb/s RGB laser diodes-based WDM underwater wireless optical communication

Meiwei Kong, Weichao Lv, Tariq Ali, Rohail Sarwar, Chuying Yu, Yang Qiu, Fengzhong Qu, Zhiwei Xu, Jun Han, and Jing Xu
Opt. Express 25(17) 20829-20834 (2017)

Underwater wireless optical communication using an arrayed transmitter/receiver and optical superimposition-based PAM-4 signal

Meiwei Kong, Yifei Chen, Rohail Sarwar, Bin Sun, Zhiwei Xu, Jun Han, Jiawang Chen, Huawei Qin, and Jing Xu
Opt. Express 26(3) 3087-3097 (2018)

Experimental demonstration of 50-m/5-Gbps underwater optical wireless communication with low-complexity chaotic encryption

Ji Du, Yuan Wang, Chao Fei, Ruilin Chen, Guowu Zhang, Xiaojian Hong, and Sailing He
Opt. Express 29(2) 783-796 (2021)

34.5 m underwater optical wireless communication with 2.70 Gbps data rate based on a green laser diode with NRZ-OOK modulation

Xiaoyan Liu, Suyu Yi, Xiaolin Zhou, Zhilai Fang, Zhi-Jun Qiu, Laigui Hu, Chunxiao Cong, Lirong Zheng, Ran Liu, and Pengfei Tian
Opt. Express 25(22) 27937-27947 (2017)

Net 4 Gb/s underwater optical wireless communication system over 2 m using a single-pixel GaN-based blue mini-LED and linear equalization

Xueyang Li, Chen Cheng, Chao Zhang, Zixian Wei, Lai Wang, H. Y. Fu, and Yanfu Yang
Opt. Lett. 47(8) 1976-1979 (2022)