A 5 m/25 Gbps Underwater Wireless Optical Communication System

Abstract

A 25-Gbps underwater wireless optical communication (UWOC) system with a two-stage injection-locked 680-nm red-light vertical-cavity surface-emitting laser (VCSEL) transmitter to enhance the frequency response and a laser beam expander to expand the collimated beam diameter over a 5-m highly turbid harbor water link is proposed and practically demonstrated. In highly turbid harbor water link, the overall attenuation coefficient at 680 nm is smaller than that at 520 and 450 nm, thereby a 680-nm red-light VCSEL transmitter is adopted in this proposed 5 m/25 Gbps UWOC system rather than a 520-nm green-light laser diode (LD) transmitter or a 450-nm blue-light LD transmitter. A satisfactory bit error rate performance (3 × 10 -9 ) and a clear eye diagram are acquired in real time. This proposed UWOC system with a two-stage injection-locked 680-nm VCSEL transmitter and a laser beam expander brings important improvements in the scenario characterized by high turbidity.

Impact of Turbulent-Flow-Induced Scintillation on Deep-Ocean Wireless Optical Communication

“…Since 2015, which was the early stage of underwater wireless optical communication (UWOC) research, Hassan et al [4] have achieved a 5-m UWOC system with a data rate of 4.8 Gigabits per second (Gbps). In 2017, 20-m UWOC link with 1.5 Gbps data rate was built by Shen et al [5], and Xu et al [6] pushed the data rate to 9.51 Gbps over 10 m. In 2018, a 25-Gbps UWOC system over a 5-m underwater channel was achieved by Li et al [7]. Based on these results, UWOC techniques are expected to be combined with underwater vehicles to improve marine observation in the future [8].…”

15.73 Gb/s Visible Light Communication With Off-the-Shelf LEDs

“…Over the past few years several giga-bit-per-second experimental WDM-VLC demonstrations have been reported [11]. Laser-based experiments have shown achievable data rates up to 25 Gb/s for underwater VLC [12]- [16]. However, laser-based VLC requires consideration of eye-safety and the required power reduction may significantly reduce the achievable data rates.…”

A tutorial on laser-based lighting and visible light communications: device and technology [Invited]

“…A recent review on UWOC can be found in [23,30]. In 2018, Li et al [31] achieved a 5-m, 25-Gbps data rate UWOC system. Fig.…”

“…Fig. 2 shows the recent research progress in UWOC [27,28,[31][32][33][34][35][36][37][38][39][40]. In contrast to LEDs, LD and superluminescent diode (SLD) emerge as alternative light sources for achieving high Gbps data rates owing to their short relaxation time and not being subject to problems of efficiency roll off.…”