Laser-based white-light source for high-speed underwater wireless optical communication and high-efficiency...

Area of Science:

• Optical Engineering
• Wireless Communication
• Solid-State Lighting

Background:

• Underwater wireless optical communication (UWOC) and solid-state lighting (SSL) are crucial for subaquatic exploration and operations.
• Existing systems often require separate hardware for communication and lighting, increasing complexity and cost.
• Developing integrated solutions for high-speed data transmission and efficient lighting in underwater environments is a significant challenge.

Purpose of the Study:

• To propose and experimentally demonstrate a novel system for simultaneous high-speed UWOC and high-efficiency underwater SSL.
• To investigate the performance of red, green, and blue laser diodes (RGB LDs) for generating white light for these dual applications.
• To evaluate the impact of optical diffusers on both UWOC data rates and SSL quality.

Main Methods:

• Generation of white light by mixing RGB laser diodes (LDs).
• Experimental setup for UWOC and underwater SSL over a 2.3 m link.
• Utilizing on-off keying (OOK) modulation and wavelength-division multiplexing (WDM) for data transmission.
• Characterization of UWOC performance (data rate, BER) and SSL quality (illuminance, color properties) with and without optical diffusers.

Main Results:

• Individual RGB LDs achieved real-time data rates up to 3.4 Gbps with low bit error rates (BERs).
• An aggregate UWOC data rate of 9.7 Gbps was achieved using RGB LDs-based WDM.
• The system without diffusers reached 8.7 Gbps UWOC with excellent lighting quality (6322 K CCT, 7084 lux illuminance).
• With diffusers, data rates of 5.9 Gbps and 6.6 Gbps were achieved, enabling large-area SSL.

Conclusions:

• The proposed RGB LDs-based system effectively integrates high-speed UWOC and high-efficiency underwater SSL.
• The system demonstrates flexibility in performance by adjusting parameters and using optical diffusers.
• This technology holds significant potential for future underwater applications requiring both robust communication and illumination.