• Photonics Research
  • Vol. 9, Issue 8, 08001581 (2021)
Fangchen Hu1, Shouqing Chen2, Guoqiang Li1, Peng Zou1, Junwen Zhang1, Jian Hu2, Jianli Zhang2, Zhixue He3, Shaohua Yu3, Fengyi Jiang2, and Nan Chi1、*
Author Affiliations
  • 1Key Laboratory for Information Science of Electromagnetic Waves (MoE), Department of Communication Science and Engineering, Fudan University, Shanghai 200433, China
  • 2National Institute of LED on Silicon Substrate, Nanchang University, Nanchang 330096, China
  • 3State Key Laboratory of Optical Communication Technologies and Networks, China Information Communication Technologies Group Corporation, Wuhan 430074, China
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    Abstract

    High-speed visible light communication (VLC) using light-emitting diodes (LEDs) is a potential complementary technology for beyond-5G wireless communication networks. The speed of VLC systems significantly depends on the quality of LEDs, and thus various novel LEDs with enhanced VLC performance increasingly emerge. Among them, InGaN/GaN-based LEDs on a Si-substrate are a promising LED transmitter that has enabled VLC data rates beyond 10 Gbps. The optimization on the period number of superlattice interlayer (SL), which is a stress-relief epitaxial layer in a Si-substrate LED, has been demonstrated to be an effective method to improve Si-substrate LED’s luminescence properties. However, this method to improve LED’s VLC properties is barely investigated. Hence, we for the first time experimentally studied the impact of SL period number on VLC performance. Accordingly, we designed and fabricated an integrated 4 × 4 multichromatic Si-substrate wavelength-division-multiplexing LED array chip with optimal SL period number. This chip allows up to 24.25 Gbps/1.2 m VLC transmission using eight wavelengths, which is the highest VLC data rate for an InGaN/GaN LED-based VLC system to the best of our knowledge. Additionally, a record-breaking data rate of 2.02 Gbps over a 20-m VLC link is achieved using a blue Si-substrate LED with the optimal SL period number. These results validate the effectiveness of Si-substrate LEDs for both high-speed and long-distance VLC and pave the way for Si-substrate LED design specially for high-speed VLC applications.

    1. INTRODUCTION

    Driven by the congestion of available radio frequency spectrum resources and the ever-increasing demand for wireless network capacity in the upcoming sixth-generation (6G) networks [1,2], visible light communication (VLC) using mass-market illumination light-emitting diodes (LEDs) has attracted considerable attention due to the sufficient visible light spectrum resource (400–800 THz) and high data rate (theoretically up to terabytes per second [3]). Additionally, VLC has the potential to be integrated into existing solid-state lighting systems, which enables the combination of illumination and wireless communication [4]. Therefore, many efforts have been made to optimize VLC systems to achieve higher data rates and longer transmission distances for more practical applications [59].