High-speed underwater optical wireless communication using a blue GaN-based micro-LED

Area of Science:

• Optoelectronics
• Wireless Communication
• Materials Science

Background:

• Underwater optical wireless communication (UOWC) faces challenges in data rate and transmission distance.
• Gallium Nitride (GaN)-based micro-light-emitting diodes (LEDs) offer potential for high-speed optical communication due to their properties.

Purpose of the Study:

• To demonstrate high-speed UOWC using a blue-emitting GaN-based micro-LED.
• To evaluate the performance of the micro-LED in underwater environments.
• To explore the feasibility of extended-range UOWC.

Main Methods:

• Utilized an 80 μm blue-emitting GaN-based micro-LED with a peak emission wavelength of ~440 nm.
• Measured underwater power attenuation in tap water (1 dB/m).
• Characterized the micro-LED's modulation bandwidth (~160 MHz) and tested data transmission at various distances and bit error rates (BER).

Main Results:

• Achieved an 800 Mb/s data rate at 0.6 m with a BER of 1.3 × 10^-3, below forward error correction (FEC) limits.
• Demonstrated 100 Mb/s at -40 dBm with a BER of 1.9 × 10^-3, suggesting extended-range capability.
• Experimentally achieved 200 Mb/s at 5.4 m using mirrors for beam reflection, with a BER of 3.0 × 10^-6.

Conclusions:

• The blue-emitting GaN-based micro-LED is suitable for high-speed UOWC.
• The system demonstrated robust performance, achieving high data rates over significant underwater distances.
• The results suggest UOWC technology can be advanced for practical, long-range underwater communication applications.