Overview of LED industry standardization The energy-saving and environmentfriendly features of the LED technology provide anticipated solutions to completely break through the high energy consumption dilemma in human...Overview of LED industry standardization The energy-saving and environmentfriendly features of the LED technology provide anticipated solutions to completely break through the high energy consumption dilemma in human illumination. Over the past decade, the LED industry has grown remarkably, reflected by the increase of the photoelectric conversion efficiency for LED from around 201m/W in 2003 to 1301m/W in 2013. A complete industry chain has come into being globally, ranging from the upstream chip production to the encapsulating in the middle and the downstream LED applications. Those time-cherished multinationals （e.g. Philips, OSRAM, CREE） in the lighting industry also accomplished the recombination and transformation toward the LED technologies.展开更多
Although the 5G wireless network has made significant advances,it is not enough to accommodate the rapidly rising requirement for broader bandwidth in post-5G and 6G eras.As a result,emerging technologies in higher fr...Although the 5G wireless network has made significant advances,it is not enough to accommodate the rapidly rising requirement for broader bandwidth in post-5G and 6G eras.As a result,emerging technologies in higher frequencies including visible light communication(VLC),are becoming a hot topic.In particular,LED-based VLC is foreseen as a key enabler for achieving data rates at the Tb/s level in indoor scenarios using multi-color LED arrays with wavelength division multiplexing(WDM)technology.This paper proposes an optimized multi-color LED array chip for high-speed VLC systems.Its long-wavelength GaN-based LED units are remarkably enhanced by V-pit structure in their efficiency,especially in the“yellow gap”region,and it achieves significant improvement in data rate compared with earlier research.This work investigates the V-pit structure and tries to provide insight by introducing a new equivalent circuit model,which provides an explanation of the simulation and experiment results.In the final test using a laboratory communication system,the data rates of eight channels from short to long wavelength are 3.91 Gb/s,3.77 Gb/s,3.67 Gb/s,4.40 Gb/s,3.78 Gb/s,3.18 Gb/s,4.31 Gb/s,and 4.35 Gb/s(31.38 Gb/s in total),with advanced digital signal processing(DSP)techniques including digital equalization technique and bit-power loading discrete multitone(DMT)modulation format.展开更多
文摘Overview of LED industry standardization The energy-saving and environmentfriendly features of the LED technology provide anticipated solutions to completely break through the high energy consumption dilemma in human illumination. Over the past decade, the LED industry has grown remarkably, reflected by the increase of the photoelectric conversion efficiency for LED from around 201m/W in 2003 to 1301m/W in 2013. A complete industry chain has come into being globally, ranging from the upstream chip production to the encapsulating in the middle and the downstream LED applications. Those time-cherished multinationals （e.g. Philips, OSRAM, CREE） in the lighting industry also accomplished the recombination and transformation toward the LED technologies.
基金This research was funded by the National Key Research and Development Program of China(2022YFB2802803)the Natural Science Foundation of China Project(No.61925104,No.62031011,No.62201157,No.62074072).
文摘Although the 5G wireless network has made significant advances,it is not enough to accommodate the rapidly rising requirement for broader bandwidth in post-5G and 6G eras.As a result,emerging technologies in higher frequencies including visible light communication(VLC),are becoming a hot topic.In particular,LED-based VLC is foreseen as a key enabler for achieving data rates at the Tb/s level in indoor scenarios using multi-color LED arrays with wavelength division multiplexing(WDM)technology.This paper proposes an optimized multi-color LED array chip for high-speed VLC systems.Its long-wavelength GaN-based LED units are remarkably enhanced by V-pit structure in their efficiency,especially in the“yellow gap”region,and it achieves significant improvement in data rate compared with earlier research.This work investigates the V-pit structure and tries to provide insight by introducing a new equivalent circuit model,which provides an explanation of the simulation and experiment results.In the final test using a laboratory communication system,the data rates of eight channels from short to long wavelength are 3.91 Gb/s,3.77 Gb/s,3.67 Gb/s,4.40 Gb/s,3.78 Gb/s,3.18 Gb/s,4.31 Gb/s,and 4.35 Gb/s(31.38 Gb/s in total),with advanced digital signal processing(DSP)techniques including digital equalization technique and bit-power loading discrete multitone(DMT)modulation format.
