Paper
20 December 2019 Study of the modulating efficiency of white LED with different rated powers
Lin Gui, Su-zhen Song, Yu-xuan Zhu, Honglin Shen, Xueyi Cai, Zixin Zhu
Author Affiliations +
Proceedings Volume 11209, Eleventh International Conference on Information Optics and Photonics (CIOP 2019); 112092Q (2019) https://doi.org/10.1117/12.2548544
Event: Eleventh International Conference on Information Optics and Photonics (CIOP 2019), 2019, Xi'an, China
Abstract
For a VLC system, it transmits information by modulating LED with electrical signal. To ensure the sufficient optical power at the receiver, the electrical signal with large amplitude is hope to be applied on the LED , however, the LED has the turn-on voltage and the saturated voltage, so large electrical signal in transmitter will lead to the clipping distortion on the LED in theory. In this paper, the modulating efficiencies of white light LED with the rated power 1W, 0.5W and 0.1W are measured in experiment with the biased voltage 3.4V, and their modulating property are compared when the peak-peak AC voltage of the frequency 500KHz are in the range 0.5V-2.1Vpp and 2.2-5Vpp. In the experiment, an Arbitrary waveform generator (AWG) with the voltage bias function is utilized to generate a biased sine waveform Experimental results show that the slopes of Pe-Vt curve(modulating efficiency) increase with the drop of the rated power of LED at the frequency 500KHz in region I. In region II, the slopes of 1W LED and 0.1W LED are larger than that of 0.5W LED. The modulating efficiency is higher in region II than that in region I. When LED operate at the clipping distortion region, it has large modulating efficiency. Data fitting analysis shows that the 1W LED has the poor linearity in both region because its R-squares in both regions are smaller than other LEDs. The nonlinearity of the Pe-Vt curve will affect the modulating efficiency.
© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Lin Gui, Su-zhen Song, Yu-xuan Zhu, Honglin Shen, Xueyi Cai, and Zixin Zhu "Study of the modulating efficiency of white LED with different rated powers", Proc. SPIE 11209, Eleventh International Conference on Information Optics and Photonics (CIOP 2019), 112092Q (20 December 2019); https://doi.org/10.1117/12.2548544
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KEYWORDS
Light emitting diodes

Modulation

Distortion

Signal detection

Transmitters

Detection theory

Free space optics

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