Active tracking system for visible light communication using a GaN-based micro-LED and NRZ-OOK.

Area of Science:

• Optoelectronics
• Wireless Communication

Background:

• Visible Light Communication (VLC) offers high-speed indoor wireless networking potential, competing with 5G radio frequency (RF) systems.
• Gallium Nitride (GaN) based micro-light-emitting-diodes (micro-LEDs) have advanced modulation bandwidths, but reduced light collection impacts signal-to-noise ratio (SNR).
• Practical high data-rate VLC requires effective focusing optics and tracking systems.

Purpose of the Study:

• To demonstrate an active on-chip tracking system for GaN-based micro-LED VLC.
• To enhance the performance and practicality of VLC systems.
• To overcome limitations in light collection and SNR for high-speed VLC.

Main Methods:

• Development and implementation of an active on-chip tracking system.
• Utilizing GaN-based micro-LEDs and none-return-to-zero on-off keying (NRZ-OOK).
• Integration of focusing optics and a tracking mechanism within the VLC system.

Main Results:

• Achieved an enlarged field of view (FOV) of 120°.
• Demonstrated data rates up to 600 Mbps with a bit error rate (BER) of 2.1×10⁻⁴.
• Enabled high-speed VLC without the need for manual focusing.

Conclusions:

• The developed active tracking system significantly enhances VLC communication quality.
• This technology optimizes VLC for practical, high data-rate communication applications.
• The system overcomes previous limitations, paving the way for more robust VLC links.