A simple and effective interference-fading tolerant method for phase-sensitive optical time-domain reflectometry(Φ-OTDR) using optimal peak-seeking is proposed. This method can reconstruct the vibration signal with h...A simple and effective interference-fading tolerant method for phase-sensitive optical time-domain reflectometry(Φ-OTDR) using optimal peak-seeking is proposed. This method can reconstruct the vibration signal with high fidelity under the premise of using only an ordinary single-mode sensing fiber without changing the structure of the traditional Φ-OTDR system. Based on the data after interference suppression, we applied different machine learning models to recognize the invasive events category. The promising results show potential applications of Φ-OTDR equipment and future implementation with machine learning algorithms.展开更多
While total internal reflection(TIR)lays the foundation for many important applications,foremost fibre optics that revolutionised information technologies,it is undesirable in some other applications such as light-emi...While total internal reflection(TIR)lays the foundation for many important applications,foremost fibre optics that revolutionised information technologies,it is undesirable in some other applications such as light-emitting diodes(LEDs),which are a backbone for energy-efficient light sources.In the case of LEDs,TIR prevents photons from escaping the constituent high-index materials.Advances in material science have led to good efficiencies in generating photons from electron–hole pairs,making light extraction the bottleneck of the overall efficiency of LEDs.In recent years,the extraction efficiency has been improved,using nanostructures at the semiconductor/air interface that outcouple trapped photons to the outside continuum.However,the design of geometrical features for light extraction with sizes comparable to or smaller than the optical wavelength always requires sophisticated and timeconsuming fabrication,which causes a gap between lab demonstration and industrial-level applications.Inspired by lightning bugs,we propose and realise a disordered metasurface for light extraction throughout the visible spectrum,achieved with single-step fabrication.By applying such a cost-effective light extraction layer,we improve the external quantum efficiency by a factor of 1.65 for commercialised GaN LEDs,demonstrating a substantial potential for global energy-saving and sustainability.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 61627816 and 61975076)the Beijing Natural Science Foundation (No. 4192042)+2 种基金the Key Research and Development Program of Jiangsu Province (No. BE2018047)the Natural Science Foundation of Jiangsu Province (No. BK20180328)the Key Technology R&D Program of Inner Mongolia Autonomous Region。
文摘A simple and effective interference-fading tolerant method for phase-sensitive optical time-domain reflectometry(Φ-OTDR) using optimal peak-seeking is proposed. This method can reconstruct the vibration signal with high fidelity under the premise of using only an ordinary single-mode sensing fiber without changing the structure of the traditional Φ-OTDR system. Based on the data after interference suppression, we applied different machine learning models to recognize the invasive events category. The promising results show potential applications of Φ-OTDR equipment and future implementation with machine learning algorithms.
基金P.M.and M.H.acknowledge the financial support from by National Natural Science Foundation of China(Grant No.11627806,U1909214,11604161)the National Key R&D Program of China(Grant No.2016YFA0201002)+5 种基金P.M.acknowledges the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant(Grant No.752102)C.L.acknowledges the financial support from Humboldt Research Fellowship from Alexander von Humboldt Foundation.P.M.,C.L.and S.Z acknowledge 2020 European Research Council Project Nos.734578(D-SPA)and 648783(TOPOLOGICAL)Leverhulme Trust(grant no.RPG-2012-674)the Royal Society,the Wolfson Foundation.S.A.M.acknowledges funding support from the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy,EXC 2089/1-390776260the Solar Energies go Hybrid(SolTech)programme,the EPSRC Reactive Plasmonics Programme(EP/M013812/1)the Lee-Lucas Chair in Physics.X.L.,M.L.and E.S.acknowledge financial support from the Natural Sciences and Engineering Research Council(NSERC)of Canada.
文摘While total internal reflection(TIR)lays the foundation for many important applications,foremost fibre optics that revolutionised information technologies,it is undesirable in some other applications such as light-emitting diodes(LEDs),which are a backbone for energy-efficient light sources.In the case of LEDs,TIR prevents photons from escaping the constituent high-index materials.Advances in material science have led to good efficiencies in generating photons from electron–hole pairs,making light extraction the bottleneck of the overall efficiency of LEDs.In recent years,the extraction efficiency has been improved,using nanostructures at the semiconductor/air interface that outcouple trapped photons to the outside continuum.However,the design of geometrical features for light extraction with sizes comparable to or smaller than the optical wavelength always requires sophisticated and timeconsuming fabrication,which causes a gap between lab demonstration and industrial-level applications.Inspired by lightning bugs,we propose and realise a disordered metasurface for light extraction throughout the visible spectrum,achieved with single-step fabrication.By applying such a cost-effective light extraction layer,we improve the external quantum efficiency by a factor of 1.65 for commercialised GaN LEDs,demonstrating a substantial potential for global energy-saving and sustainability.
