Laser-based white-light source for high-speed underwater wireless optical communication and high-efficiency underwater solid-state lighting

Abstract

White light generated by mixing the red, green, and blue laser diodes (RGB LDs) for simultaneous high-speed underwater wireless optical communication (UWOC) and high-efficiency underwater solid-state lighting (SSL) was proposed and demonstrated experimentally for the first time. The allowable maximum real-time data transmission rates of 3.2 Gbps, 3.4 Gbps, and 3.1 Gbps for RGB LDs with corresponding BERs of 3.6 × 10, 3.5 × 10 and 3.7 × 10 were obtained at a 2.3 m underwater transmission distance using an on-off keying (OOK) modulation scheme, respectively. And the corresponding UWOC aggregate data rate of 9.7 Gbps was achieved based on RGB LDs-based wavelength-division multiplexing (WDM) UWOC. Moreover, UWOC and underwater SSL by using RGB LDs mixed white light were investigated at different scenarios over an underwater link of 2.3 m. The RGB LDs mixed white light-based UWOC system without optical diffusers yielded a maximum allowable data rate of 8.7 Gbps with Commission International de l'Eclairage coordinates (CIE) of (0.3154, 0.3354), a correlated color temperature of 6322 K, a color rendering index of 69.3 and a corresponding illuminance of 7084 lux. Furthermore, optical diffusers were employed to provide large-area underwater SSL. The LDs mixed white light-based UWOC system with line and circle optical diffusers implemented data rates of 5.9 Gbps and 6.6 Gbps with CIE coordinates of (0.3183, 0.3269) and (0.3298, 0.3390), respectively. This work suggests the potential of LDs for applications in high-efficiency underwater white-light SSL and high-speed UWOC.

Toward Long-Distance Underwater Wireless Optical Communication Based on A High-Sensitivity Single Photon Avalanche Diode

“…From Fig. 9, the attenuation coefficient is close to the reported value in the literature [27]. And it can be seen that as laser divergence angles increase, the attenuation coefficients also increase slowly.…”

“…From the experimental 2.3-m water tank and formula (1), we can get the attenuation coefficient c of 0.12 m −1 . The coefficient is slightly lower than the reported value [27], resulting from better optical alignment. With low attenuation coefficients, the link loss of the optical output power is decreased, so higher receiving optical power and longer distances can be obtained.…”

Using SiO₂ nano-particles for better color uniformity and lumen output in 8500 K conformal and in-cup white LEDs

“…Moreover, the refractive indices (RI) of silicone, phosphor, SiO2 nanoparticle are 1.4, 1.8 and 2.23. Thus, the RI of the phosphor layer with SiO2 nanoparticle is computed using (1) [24], [25].…”

Real-Time Multi-User Video Optical Wireless Transmission Based on a Parallel Micro-LEDs Bulb

“…For reducing the complexity of systems, H. M. Oubei et al adopted onoff keying non-return-to-zero (NRZ-OOK) modulation scheme to achieve 2.3-Gbps transmission over a 7-m underwater link by using 520-nm LD [10]. Besides, in order to simultaneously realize the function of communication and illumination underwater, red, green, and blue LDs (RGB-LDs) are used to generate white light in [11]. Although VLC systems based on LDs have longer transmission distance and higher modulation bandwidth, the LDs need more cost than LEDs and have safety issues for human eyes.…”