Due to the excellent optoelectronic properties,fast response time,outstanding power efficiency and high stability,micro-LED plays an increasingly important role in the new generation of display technology compared wit...Due to the excellent optoelectronic properties,fast response time,outstanding power efficiency and high stability,micro-LED plays an increasingly important role in the new generation of display technology compared with LCD and OLED display.This paper mainly introduces the preparation methods of the GaN-based micro-LED array,the optoelectronic characteristics,and several key technologies to achieve full-color display,such as transfer printing,color conversion by quantum dot and local strain engineering.展开更多
Rain has a strong attenuation effect on light,which can impact the performance of visible light communication(VLC).In this paper,we addressed the crucial challenge of implementing high-speed VLC systems in rainy envir...Rain has a strong attenuation effect on light,which can impact the performance of visible light communication(VLC).In this paper,we addressed the crucial challenge of implementing high-speed VLC systems in rainy environments by focusing on the performance of different wavelengths under varying rain conditions.By analyzing the attenuation characteristics of four laser diodes at different wavelengths under various artificial rain environments,we developed a high-speed VLC system optimized for rainy channel high-speed visible light communication by employing the orthogonal frequency-division multiplexing modulation scheme.By integrating channel-adaptive pre-equalization and bit-loading algorithms,our system optimized signal transmission in rainy channels,enabling an aggregated data rate exceeding 30 Gbps,which was the highest reported data rate for VLC in rainy channels,to the best of our knowledge.展开更多
In this work,a blue gallium nitride(GaN)micro-light-emitting-diode(micro-LED)-based underwater wireless optical communication(UWOC)system was built,and UWOCs with varied Maalox,chlorophyll,and sea salt concentrations ...In this work,a blue gallium nitride(GaN)micro-light-emitting-diode(micro-LED)-based underwater wireless optical communication(UWOC)system was built,and UWOCs with varied Maalox,chlorophyll,and sea salt concentrations were studied.Data transmission performance of the UWOC and the influence of light attenuation were investigated systematically.Maximum data transmission rates at the distance of 2.3 m were 933,800,910,and 790 Mbps for experimental conditions with no impurity,200.48 mg/m3 Maalox,12.07 mg/m3 chlorophyll,and 5 kg/m3 sea salt,respectively,much higher than previously reported systems with commercial LEDs.It was found that increasing chlorophyll,Maalox,and sea salt concentrations in water resulted in an increase of light attenuation,which led to the performance degradation of the UWOC.Further analysis suggests two light attenuation mechanisms,e.g.,absorption by chlorophyll and scattering by Maalox,are responsible for the decrease of maximum data rates and the increase of bit error rates.Based on the absorption and scattering models,excellent fitting to the experimental attenuation coefficient can be achieved,and light attenuation by absorption and scattering at different wavelengths was also investigated.We believe this work is instructive apply UWOC for practical applications.展开更多
Due to the bandwidth limitation of the ultraviolet-C(UV-C) optical communication system and strong channel attenuation, it is difficult to transmit high-frequency signals. In this paper, the temporal ghost imaging(TGI...Due to the bandwidth limitation of the ultraviolet-C(UV-C) optical communication system and strong channel attenuation, it is difficult to transmit high-frequency signals. In this paper, the temporal ghost imaging(TGI) algorithm was first applied to the UV-C communication experimentally, and we realized the transmission of a 4 GHz signal through 95.34 MHz system bandwidth. The study indicates that the TGI algorithm can significantly improve the signal-to-noise ratio(SNR) compared with the on–off keying method. Our research provides a new approach for alleviating transmission frequency limitation due to poor SNR and insufficient hardware bandwidth.展开更多
Multicolor series connection micro-LED arrays with emission wavelengths of violet, blue, green, and yellow were fabricated, and their optoelectronic properties and communication performances were investigated. The des...Multicolor series connection micro-LED arrays with emission wavelengths of violet, blue, green, and yellow were fabricated, and their optoelectronic properties and communication performances were investigated. The designed series connection micro-LED array exhibited the light output power of multiple milliwatts, whereas mostly keeping a slightly reduced modulation bandwidth, thus, enabling a higher signal-to-noise ratio compared to a single pixel and showing superior performance in the field of long-distance visible light communication(VLC). The achievable data rates of 400-, 451-, 509-, and 556-nm micro-LED arrays using bit/power loading orthogonal frequency division multiplexing were 5.71, 4.86, 4.39, and 0.82 Gbps, respectively. The aggregate data rate of 15.78 Gbps was achieved for the proof-of-concept wavelength division multiplexing system under a transmission distance of 13 m, which was the best data rate-distance product performance for the LED-based VLC to the best of our knowledge. In addition, the long-distance VLC based on yellow micro-LED was also demonstrated for the first time in this paper.展开更多
基金National Natural Science Foundation of China(NSFC)(61974031,61705041 and 61571135)Shanghai Sailing Program(17YF1429100)+2 种基金Shanghai Technical Standard Program(18DZ2206000)State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Funding(SKLIPR1607)National Key Research and Development Program of China(2017YFB0403603).
文摘Due to the excellent optoelectronic properties,fast response time,outstanding power efficiency and high stability,micro-LED plays an increasingly important role in the new generation of display technology compared with LCD and OLED display.This paper mainly introduces the preparation methods of the GaN-based micro-LED array,the optoelectronic characteristics,and several key technologies to achieve full-color display,such as transfer printing,color conversion by quantum dot and local strain engineering.
基金supported by the National Key Research and Development Program of China(No.2021YFB3601003)。
文摘Rain has a strong attenuation effect on light,which can impact the performance of visible light communication(VLC).In this paper,we addressed the crucial challenge of implementing high-speed VLC systems in rainy environments by focusing on the performance of different wavelengths under varying rain conditions.By analyzing the attenuation characteristics of four laser diodes at different wavelengths under various artificial rain environments,we developed a high-speed VLC system optimized for rainy channel high-speed visible light communication by employing the orthogonal frequency-division multiplexing modulation scheme.By integrating channel-adaptive pre-equalization and bit-loading algorithms,our system optimized signal transmission in rainy channels,enabling an aggregated data rate exceeding 30 Gbps,which was the highest reported data rate for VLC in rainy channels,to the best of our knowledge.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.61705041 and61571135)Shanghai Sailing Program(No.17YF1429100)+2 种基金Shanghai Technical Standard Program(No.18DZ2206000)State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Funding(No.SKLIPR1607)National Key Research and Development Program of China(No.2017YFB0403603)
文摘In this work,a blue gallium nitride(GaN)micro-light-emitting-diode(micro-LED)-based underwater wireless optical communication(UWOC)system was built,and UWOCs with varied Maalox,chlorophyll,and sea salt concentrations were studied.Data transmission performance of the UWOC and the influence of light attenuation were investigated systematically.Maximum data transmission rates at the distance of 2.3 m were 933,800,910,and 790 Mbps for experimental conditions with no impurity,200.48 mg/m3 Maalox,12.07 mg/m3 chlorophyll,and 5 kg/m3 sea salt,respectively,much higher than previously reported systems with commercial LEDs.It was found that increasing chlorophyll,Maalox,and sea salt concentrations in water resulted in an increase of light attenuation,which led to the performance degradation of the UWOC.Further analysis suggests two light attenuation mechanisms,e.g.,absorption by chlorophyll and scattering by Maalox,are responsible for the decrease of maximum data rates and the increase of bit error rates.Based on the absorption and scattering models,excellent fitting to the experimental attenuation coefficient can be achieved,and light attenuation by absorption and scattering at different wavelengths was also investigated.We believe this work is instructive apply UWOC for practical applications.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(Nos.61974031 and 61705041)Fudan University-CIOMP Joint Fund(No.FC2020-001)Shanghai Technical Standard Program(No.18DZ2206000).
文摘Due to the bandwidth limitation of the ultraviolet-C(UV-C) optical communication system and strong channel attenuation, it is difficult to transmit high-frequency signals. In this paper, the temporal ghost imaging(TGI) algorithm was first applied to the UV-C communication experimentally, and we realized the transmission of a 4 GHz signal through 95.34 MHz system bandwidth. The study indicates that the TGI algorithm can significantly improve the signal-to-noise ratio(SNR) compared with the on–off keying method. Our research provides a new approach for alleviating transmission frequency limitation due to poor SNR and insufficient hardware bandwidth.
基金National Key Research and Development Program of China(2021YFB3601000,2021YFB3601003,2021YFE0105300)National Natural Science Foundation of China(61974031)+1 种基金Science and Technology Commission of Shanghai Municipality(21511101303)Leading-edge Technology Program of Jiangsu Natural Science Foundation(BE2021008-2)。
文摘Multicolor series connection micro-LED arrays with emission wavelengths of violet, blue, green, and yellow were fabricated, and their optoelectronic properties and communication performances were investigated. The designed series connection micro-LED array exhibited the light output power of multiple milliwatts, whereas mostly keeping a slightly reduced modulation bandwidth, thus, enabling a higher signal-to-noise ratio compared to a single pixel and showing superior performance in the field of long-distance visible light communication(VLC). The achievable data rates of 400-, 451-, 509-, and 556-nm micro-LED arrays using bit/power loading orthogonal frequency division multiplexing were 5.71, 4.86, 4.39, and 0.82 Gbps, respectively. The aggregate data rate of 15.78 Gbps was achieved for the proof-of-concept wavelength division multiplexing system under a transmission distance of 13 m, which was the best data rate-distance product performance for the LED-based VLC to the best of our knowledge. In addition, the long-distance VLC based on yellow micro-LED was also demonstrated for the first time in this paper.
