Phosphorous Diffuser Diverged Blue Laser Diode for Indoor Lighting and Communication.

Area of Science:

• Optoelectronics
• Photonics
• Wireless Communication

Background:

• Visible Light Communication (VLC) offers a promising alternative for high-speed wireless data transmission.
• Gallium Nitride (GaN) laser diodes (LDs) are key components in modern lighting and communication systems.
• Integrating white lighting and VLC functionalities is crucial for efficient indoor environments.

Purpose of the Study:

• To demonstrate an advanced light-fidelity (Li-Fi) system using a blue GaN LD and a white-light phosphor diffuser.
• To fuse indoor white lighting and visible light communication (VLC) capabilities into a single device.
• To explore the potential of this system for future hybrid applications.

Main Methods:

• Utilizing a blue Gallium nitride (GaN) laser diode (LD) integrated with a compact white-light phosphor diffuser.
• Broadening the luminescent spectrum and diverging the beam spot using the phosphor diffuser.
• Employing orthogonal frequency-division multiplexing (OFDM) with 16-quadrature-amplitude modulation (16-QAM) for data transmission.

Main Results:

• The phosphor diffuser enabled a wide radiant angle of up to 120 degrees, providing quality white lighting.
• The system achieved a state-of-the-art data rate of 5.2-Gbit/s with a bit error rate (BER) of 3.1 × 10⁻³ over a 60-cm free-space link.
• Degradation in throughput frequency response was observed due to phosphor-air interface reflections.

Conclusions:

• The demonstrated blue GaN LD system with a phosphor diffuser effectively integrates white lighting and VLC.
• The system shows high potential for future hybrid white-lighting and VLC networks.
• Further research may focus on mitigating reflection-induced degradations for enhanced performance.