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

• Published in: Optics express 2017-07, Vol.25 (15), p.17971-17981
• Main Authors: Lu, Zhijian, Tian, Pengfei, Chen, Hong, Baranowski, Izak, Fu, Houqiang, Huang, Xuanqi, Montes, Jossue, Fan, Youyou, Wang, Hongyi, Liu, Xiaoyan, Liu, Ran, Zhao, Yuji
• Format: Article
• Language: English
• ISSN: 1094-4087
• DOI: 10.1364/OE.25.017971

Visible light communication (VLC) holds the promise of a high-speed wireless network for indoor applications and competes with 5G radio frequency (RF) system. Although the breakthrough of gallium nitride (GaN) based micro-light-emitting-diodes (micro-LEDs) increases the -3dB modulation bandwidth exceptionally from tens of MHz to hundreds of MHz, the light collected onto a fast photo receiver drops dramatically, which determines the signal to noise ratio (SNR) of VLC. To fully implement the practical high data-rate VLC link enabled by a GaN-based micro-LED, it requires focusing optics and a tracking system. In this paper, we demonstrate an active on-chip tracking system for VLC using a GaN-based micro-LED and none-return-to-zero on-off keying (NRZ-OOK). Using this novel technique, the field of view (FOV) was enlarged to 120° and data rates up to 600 Mbps at a bit error rate (BER) of 2.1×10 were achieved without manual focusing. This paper demonstrates the establishment of a VLC physical link that shows enhanced communication quality by orders of magnitude, making it optimized for practical communication applications.