Scientific Reports (Jan 2017)

Tricolor R/G/B Laser Diode Based Eye-Safe White Lighting Communication Beyond 8 Gbit/s

  • Tsai-Chen Wu,
  • Yu-Chieh Chi,
  • Huai-Yung Wang,
  • Cheng-Ting Tsai,
  • Yu-Fang Huang,
  • Gong-Ru Lin

DOI
https://doi.org/10.1038/s41598-017-00052-8
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 10

Abstract

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Abstract White light generation by mixing red, green, and blue laser diodes (RGB LDs) was demonstrated with Commission International de l’Eclairage coordinates of (0.2928, 0.2981), a correlated color temperature of 8382 K, and a color rendering index of 54.4 to provide a maximal illuminance of 7540 lux. All the white lights generated using RGB LDs were set within the risk group-1 criterion to avoid the blue-light hazard to human eyes. In addition, the RGB-LD mixed white light was diffused using a frosted glass to avoid optical aberration and to improve the performance of the lighting source. In addition, visible light communication (VLC) by using RGB-LD mixed white-light carriers and a point-to-point scheme over 1 m was performed in the directly modulated 16-QAM OFDM data format. In back-to-back transmission, the maximal allowable data rate at 10.8, 10.4, and 8 Gbps was determined for R, G, and B LDs, respectively. Moreover, the RGB-LD mixed white light-based indoor wavelength-division multiplexing (WDM)-VLC system yielded a total allowable transmission data rate of 8.8 Gbps over 0.5 m in free space. Such a high-speed RGB-LD mixed WDM-VLC system without any channel interference can be used to simultaneously provide data transmission and white lighting in an indoor environment.