Manipulating motion of microobjects with light is indispensable in various technologies.On solid interfaces,its realizations,however,are hampered by surface friction.To resolve this difficulty,light-induced elastic wa...Manipulating motion of microobjects with light is indispensable in various technologies.On solid interfaces,its realizations,however,are hampered by surface friction.To resolve this difficulty,light-induced elastic waves have been recently proposed to drive microobjects against friction.Despite its expected applicability for arbitrary optical-absorptive objects,the new principle has only been tested with microsized gold plates.Herein,we validate this principle using a new material and report directional and continuous movements of a two-dimensional topological insulator(Sb2Te3)plate on an untreated microfiber surface driven by nanosecond laser pulses.The motion performance of the Sb2Te3 plate is characterized by a scanning electron microscope.We observe that the motion velocity can be controlled by tuning the average power of laser pulses.Further,by intentionally increasing the pulse repetition rate and exploiting the low thermal conductivity of Sb2Te3,we examine the thermal effects on actuation and reveal the motion instability induced by formations of microbumps on Sb2Te3 surfaces due to the Marangoni effects.Moreover,as the formed microbumps are heated to viscoelasticity states,liquid-like motion featuring asymmetry in contact angles is observed and characterized,which expands the scope of light-induced actuation of microobjects.展开更多
The emergence of influenza virus A pandemic H1N1 in April 2009 marked the first pandemic of the 21st century.In this study,we observed significant differences in the polymerase activities of two clinical 2009 H1N1 inf...The emergence of influenza virus A pandemic H1N1 in April 2009 marked the first pandemic of the 21st century.In this study,we observed significant differences in the polymerase activities of two clinical 2009 H1N1 influenza A virus isolates from Chinese and Japanese patients.Sequence comparison of the three main protein subunits(PB2,PB1,and PA)of the viral RNA-dependent RNA polymerase complex and subsequent mutational analysis revealed that a single amino acid substitution(E206K)was responsible for the observed impaired replication phenotype.Further in vitro experiments showed that presence of PAE206K decreased the replication of influenza A/WSN/33 virus in mammalian cells and a reduction in the virus’s pathogenicity in vivo.Mechanistic studies revealed that PAE206K is a temperature-sensitive mutant associated with the inability to transport PB1–PA complex to the nucleus at high temperature(39.5℃).Hence,this naturally occurring variant in the PA protein represents an ideal candidate mutation for the development of live attenuated influenza vaccines.展开更多
Refractive index(RI)sensors play an important role in various applications including biomedical analysis and food processing industries.However,developing RI sensors with both high resolution and wide linear range rem...Refractive index(RI)sensors play an important role in various applications including biomedical analysis and food processing industries.However,developing RI sensors with both high resolution and wide linear range remains a great challenge due to the tradeoff between quality(Q)factor and free spectral range(FSR)of resonance mode.Herein,the optical steelyard principle is presented to address this challenge by synergizing resonances from the FabryPerot(FP)cavity and metasurface,integrated in a hybrid configuration form on the end facet of optical fibers.Specifically,the FP resonance acting like the scale beam,offers high resolution while the plasmonic resonance acting like the weight,provides a wide linear range.Featuring asymmetric Fano spectrum due to modal coupling between these two resonances,a high Q value(~3829 in liquid)and a sensing resolution(figure of merit)of 2664 RIU^(-1)are experimentally demonstrated.Meanwhile,a wide RI sensing range(1.3301.430 in the simulation and 1.34031.3757 in the experiment)is realized,corresponding to a spectral shift across several FSRs(four and two FSRs in the simulation and experiment,respectively).The proposed steelyard RI sensing strategy is promising in versatile monitoring applications,e.g.,water salinity/turbidity and biomedical reaction process,and could be extended to other types of sensors calling for both high resolution and wide linear range.展开更多
Light carries energy and momentum,laying the physical foundation of optical manipulation that has facilitated advances in myriad scientific disciplines,ranging from biochemistry and robotics to quantum physics.Utilizi...Light carries energy and momentum,laying the physical foundation of optical manipulation that has facilitated advances in myriad scientific disciplines,ranging from biochemistry and robotics to quantum physics.Utilizing the momentum of light,optical tweezers have exemplified elegant light–matter interactions in which mechanical and optical momenta can be interchanged,whose effects are the most pronounced on micro and nano objects in fluid suspensions.In solid domains,the same momentum transfer becomes futile in the face of dramatically increased adhesion force.Effective implementation of optical manipulation should thereupon switch to the“energy”channel by involving auxiliary physical fields,which also coincides with the irresistible trend of enriching actuation mechanisms beyond sole reliance on light-momentum-based optical force.From this perspective,this review covers the developments of optical manipulation in schemes of both momentum and energy transfer,and we have correspondingly selected representative techniques to present.Theoretical analyses are provided at the beginning of this review followed by experimental embodiments,with special emphasis on the contrast between mechanisms and the practical realization of optical manipulation in fluid and solid domains.展开更多
Metafibers expand the functionalities of conventional optical fibres to unprecedented nanoscale light manipulations by integrating metasurfaces on the fibre tips,becoming an emerging light-coupling platform for both t...Metafibers expand the functionalities of conventional optical fibres to unprecedented nanoscale light manipulations by integrating metasurfaces on the fibre tips,becoming an emerging light-coupling platform for both the nanoscience and fibre optics communities.Current metafibers remain proof-of-concept demonstrations that mostly explore isolated bare fibres owing to the lack of standard interfaces with universal fibre networks.Here,we develop methodologies for fabricating well-defined plasmonic metasurfaces directly on the end facets of commercial single-mode fibre jumpers using standard planar technologies and provide the first demonstration of their practical applications in the nonlinear plasmonic regime.Featuring plug-and-play connections with fibre circuitry and arbitrary metasurface landscapes,the metafibers with tunable plasmonic resonances are implemented into fibre laser cavities,yielding all-fibre sub-picosecond(minimum 513 fs)soliton mode locked lasers at optical wavelengths of 1.5μm and 2μm,demonstrating their unusual polarimetric nonlinear transfer functions and superior saturation absorption responses.The nanofabrication process flow is compatible with existing cleanroom technologies,offering metafibers an avenue to become a regular member of functionalised fibre components.This work paves the way toward the next generation of ultrafast lasers,optical frequency combs,and ultracompact‘all-in-fibre’optical systems.展开更多
Optical fibres with diameters at micro-or sub-micrometre scale are widely adopted as a convenient tool for studying light–matter interactions.To prepare such devices,two elements are indispensable:a heat source and a...Optical fibres with diameters at micro-or sub-micrometre scale are widely adopted as a convenient tool for studying light–matter interactions.To prepare such devices,two elements are indispensable:a heat source and a pulling force.In this paper,we report a novel fibre-tapering technique in which micro-sized plasmonic heaters and elaborately deformed optical fibres are compactly combined,free of flame and bulky pulling elements.Using this technique,micro-nano fibres with abrupt taper and ultra-short transition regions were successfully fabricated,which would otherwise be a challenge for traditional techniques.The compactness of the proposed system enabled it to be further transferred to a scanning electron microscope for in-situ monitoring of the tapering process.The essential dynamics of“heat and pull”was directly visualised with nanometre precision in real time and theoretically interpreted,thereby establishing an example for future in-situ observations of micro and nanoscale light-matter interactions.展开更多
Solid solutions of the lead-free 0.88(Na_(0.5)Bi_(0.5))TiO_(3)-0.12BaTiO_(3)(NBT-BT:xSm)ferroelectric ceramics were synthesized by solid state reaction.The doping of Sm promotes the structure of the ceramics to transf...Solid solutions of the lead-free 0.88(Na_(0.5)Bi_(0.5))TiO_(3)-0.12BaTiO_(3)(NBT-BT:xSm)ferroelectric ceramics were synthesized by solid state reaction.The doping of Sm promotes the structure of the ceramics to transform toward morphotropic phase boundary,and it decreases the grain size of the ceramics.With the increase of Sm content,the ferroelectric properties are improved gradually,where the ferroelectric polarization increases and the coercive field decreases.Sm doping induces a dielectric anomaly with obvious frequency dispersion at a low temperature,exhibiting the transition from the ferroelectric to relaxor state.Moreover,the photo-luminescence spectra of NBT-BT:xSm ceramics exhibit a strong orange emission upon blue light excitation of the 400 nm to 500 nm.The emission intensities are strongly dependent on the Sm doping concentration,which reached the optimal value as the doping concentration is 0.7%.These results suggest that the NBT-BT:xSm ceramics may have significant technological promise in novel multifunctional devices.展开更多
We design,fabricate,optically and mechanically characterize wearable ultrathin coatings on various substrates,including sapphire,glass and silicon wafer.Extremely hard ceramic materials titanium nitride(TiN),aluminium...We design,fabricate,optically and mechanically characterize wearable ultrathin coatings on various substrates,including sapphire,glass and silicon wafer.Extremely hard ceramic materials titanium nitride(TiN),aluminium nitride(AlN),and titanium aluminium nitride(TiAlN)are employed as reflective,isolated and absorptive coating layer,respectively.Two types of coatings have been demonstrated.First,we deposit TiAlN after TiN on various substrates(TiAlN-TiN,total thicknesses<100 nm),achieving vivid and viewing-angle independent surface colors.The colors can be tuned by varying the thickness of TiAlN layer.The wear resistance of the colorful ultrathin optical coatings is verified by scratch tests.The Mohs hardness of commonly used surface coloring made of Si-/Ge-metals on substrates is<2.5,as soft as fingernail.However,the Mohs hardness of our TiAlN-TiN on substrates is evaulated to be 7-9,harder than quartz.Second,Fano-resonant optical coating(FROC),which can transmit and reflect the same color as a beam split filter is also obtained by successively coating TiAlN-TiN-AlN-TiN(four-layer film with a total thickness of 130 nm)on transparent substrates.The FROC coating is as hard as glass.Such wearable and color-tunable thin-film structural colors and filters may be attractive for many practical applications such as sunglasses.展开更多
基金supported by the National Natural Science Foundation of China(Nos.61927820,61905201,and 62275221)。
文摘Manipulating motion of microobjects with light is indispensable in various technologies.On solid interfaces,its realizations,however,are hampered by surface friction.To resolve this difficulty,light-induced elastic waves have been recently proposed to drive microobjects against friction.Despite its expected applicability for arbitrary optical-absorptive objects,the new principle has only been tested with microsized gold plates.Herein,we validate this principle using a new material and report directional and continuous movements of a two-dimensional topological insulator(Sb2Te3)plate on an untreated microfiber surface driven by nanosecond laser pulses.The motion performance of the Sb2Te3 plate is characterized by a scanning electron microscope.We observe that the motion velocity can be controlled by tuning the average power of laser pulses.Further,by intentionally increasing the pulse repetition rate and exploiting the low thermal conductivity of Sb2Te3,we examine the thermal effects on actuation and reveal the motion instability induced by formations of microbumps on Sb2Te3 surfaces due to the Marangoni effects.Moreover,as the formed microbumps are heated to viscoelasticity states,liquid-like motion featuring asymmetry in contact angles is observed and characterized,which expands the scope of light-induced actuation of microobjects.
基金funded by grants from Beijing Natural Science Foundation(M22031)National Key R&D Program of China(2022YFF1203200,2022YFE0202600)+1 种基金Chinese Academy of Medical Sciences(2016-12M-1-014)National Natural Science Foundation of China(81871669,32070173,31471329 and 31601151).
文摘The emergence of influenza virus A pandemic H1N1 in April 2009 marked the first pandemic of the 21st century.In this study,we observed significant differences in the polymerase activities of two clinical 2009 H1N1 influenza A virus isolates from Chinese and Japanese patients.Sequence comparison of the three main protein subunits(PB2,PB1,and PA)of the viral RNA-dependent RNA polymerase complex and subsequent mutational analysis revealed that a single amino acid substitution(E206K)was responsible for the observed impaired replication phenotype.Further in vitro experiments showed that presence of PAE206K decreased the replication of influenza A/WSN/33 virus in mammalian cells and a reduction in the virus’s pathogenicity in vivo.Mechanistic studies revealed that PAE206K is a temperature-sensitive mutant associated with the inability to transport PB1–PA complex to the nucleus at high temperature(39.5℃).Hence,this naturally occurring variant in the PA protein represents an ideal candidate mutation for the development of live attenuated influenza vaccines.
基金support from the National Natural Science Foundation of China(62275221).
文摘Refractive index(RI)sensors play an important role in various applications including biomedical analysis and food processing industries.However,developing RI sensors with both high resolution and wide linear range remains a great challenge due to the tradeoff between quality(Q)factor and free spectral range(FSR)of resonance mode.Herein,the optical steelyard principle is presented to address this challenge by synergizing resonances from the FabryPerot(FP)cavity and metasurface,integrated in a hybrid configuration form on the end facet of optical fibers.Specifically,the FP resonance acting like the scale beam,offers high resolution while the plasmonic resonance acting like the weight,provides a wide linear range.Featuring asymmetric Fano spectrum due to modal coupling between these two resonances,a high Q value(~3829 in liquid)and a sensing resolution(figure of merit)of 2664 RIU^(-1)are experimentally demonstrated.Meanwhile,a wide RI sensing range(1.3301.430 in the simulation and 1.34031.3757 in the experiment)is realized,corresponding to a spectral shift across several FSRs(four and two FSRs in the simulation and experiment,respectively).The proposed steelyard RI sensing strategy is promising in versatile monitoring applications,e.g.,water salinity/turbidity and biomedical reaction process,and could be extended to other types of sensors calling for both high resolution and wide linear range.
基金supported by the National Natural Science Foundation of China (Nos.61927820,61905201,and 62275221).
文摘Light carries energy and momentum,laying the physical foundation of optical manipulation that has facilitated advances in myriad scientific disciplines,ranging from biochemistry and robotics to quantum physics.Utilizing the momentum of light,optical tweezers have exemplified elegant light–matter interactions in which mechanical and optical momenta can be interchanged,whose effects are the most pronounced on micro and nano objects in fluid suspensions.In solid domains,the same momentum transfer becomes futile in the face of dramatically increased adhesion force.Effective implementation of optical manipulation should thereupon switch to the“energy”channel by involving auxiliary physical fields,which also coincides with the irresistible trend of enriching actuation mechanisms beyond sole reliance on light-momentum-based optical force.From this perspective,this review covers the developments of optical manipulation in schemes of both momentum and energy transfer,and we have correspondingly selected representative techniques to present.Theoretical analyses are provided at the beginning of this review followed by experimental embodiments,with special emphasis on the contrast between mechanisms and the practical realization of optical manipulation in fluid and solid domains.
文摘Metafibers expand the functionalities of conventional optical fibres to unprecedented nanoscale light manipulations by integrating metasurfaces on the fibre tips,becoming an emerging light-coupling platform for both the nanoscience and fibre optics communities.Current metafibers remain proof-of-concept demonstrations that mostly explore isolated bare fibres owing to the lack of standard interfaces with universal fibre networks.Here,we develop methodologies for fabricating well-defined plasmonic metasurfaces directly on the end facets of commercial single-mode fibre jumpers using standard planar technologies and provide the first demonstration of their practical applications in the nonlinear plasmonic regime.Featuring plug-and-play connections with fibre circuitry and arbitrary metasurface landscapes,the metafibers with tunable plasmonic resonances are implemented into fibre laser cavities,yielding all-fibre sub-picosecond(minimum 513 fs)soliton mode locked lasers at optical wavelengths of 1.5μm and 2μm,demonstrating their unusual polarimetric nonlinear transfer functions and superior saturation absorption responses.The nanofabrication process flow is compatible with existing cleanroom technologies,offering metafibers an avenue to become a regular member of functionalised fibre components.This work paves the way toward the next generation of ultrafast lasers,optical frequency combs,and ultracompact‘all-in-fibre’optical systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.61927820,61905201,and 62275221).
文摘Optical fibres with diameters at micro-or sub-micrometre scale are widely adopted as a convenient tool for studying light–matter interactions.To prepare such devices,two elements are indispensable:a heat source and a pulling force.In this paper,we report a novel fibre-tapering technique in which micro-sized plasmonic heaters and elaborately deformed optical fibres are compactly combined,free of flame and bulky pulling elements.Using this technique,micro-nano fibres with abrupt taper and ultra-short transition regions were successfully fabricated,which would otherwise be a challenge for traditional techniques.The compactness of the proposed system enabled it to be further transferred to a scanning electron microscope for in-situ monitoring of the tapering process.The essential dynamics of“heat and pull”was directly visualised with nanometre precision in real time and theoretically interpreted,thereby establishing an example for future in-situ observations of micro and nanoscale light-matter interactions.
基金supported by the Natural Science Foun-dation of China(51702169)the Natural Science Foundation of Inner Mongolia(2017BS0503)the Youth Innovation Talents Fund of Baotou and the Innovation Guide Fund for Science and Technology of Inner Mongolia Autonomous Region(KCBJ2018034).
文摘Solid solutions of the lead-free 0.88(Na_(0.5)Bi_(0.5))TiO_(3)-0.12BaTiO_(3)(NBT-BT:xSm)ferroelectric ceramics were synthesized by solid state reaction.The doping of Sm promotes the structure of the ceramics to transform toward morphotropic phase boundary,and it decreases the grain size of the ceramics.With the increase of Sm content,the ferroelectric properties are improved gradually,where the ferroelectric polarization increases and the coercive field decreases.Sm doping induces a dielectric anomaly with obvious frequency dispersion at a low temperature,exhibiting the transition from the ferroelectric to relaxor state.Moreover,the photo-luminescence spectra of NBT-BT:xSm ceramics exhibit a strong orange emission upon blue light excitation of the 400 nm to 500 nm.The emission intensities are strongly dependent on the Sm doping concentration,which reached the optimal value as the doping concentration is 0.7%.These results suggest that the NBT-BT:xSm ceramics may have significant technological promise in novel multifunctional devices.
基金supported by the National Key Research and Development Program of China(2017YFA0205700)the National Natural Science Foundation of China(NO.61927820,No.12004314,No.62105269)+3 种基金Jiao Geng is supported by Zhejiang Province Selected Funding for Postdoctoral Research Projects(No.ZJ2021044)China Postdoctoral Science Foundation(2021M702916)Liping Shi is supported by the open project program of Wuhan National Laboratory for optoelectronics No.2020WNLOKF004Zhejiang Provincial Natural Science Foundation of China under Grant No.Q21A040010.
文摘We design,fabricate,optically and mechanically characterize wearable ultrathin coatings on various substrates,including sapphire,glass and silicon wafer.Extremely hard ceramic materials titanium nitride(TiN),aluminium nitride(AlN),and titanium aluminium nitride(TiAlN)are employed as reflective,isolated and absorptive coating layer,respectively.Two types of coatings have been demonstrated.First,we deposit TiAlN after TiN on various substrates(TiAlN-TiN,total thicknesses<100 nm),achieving vivid and viewing-angle independent surface colors.The colors can be tuned by varying the thickness of TiAlN layer.The wear resistance of the colorful ultrathin optical coatings is verified by scratch tests.The Mohs hardness of commonly used surface coloring made of Si-/Ge-metals on substrates is<2.5,as soft as fingernail.However,the Mohs hardness of our TiAlN-TiN on substrates is evaulated to be 7-9,harder than quartz.Second,Fano-resonant optical coating(FROC),which can transmit and reflect the same color as a beam split filter is also obtained by successively coating TiAlN-TiN-AlN-TiN(four-layer film with a total thickness of 130 nm)on transparent substrates.The FROC coating is as hard as glass.Such wearable and color-tunable thin-film structural colors and filters may be attractive for many practical applications such as sunglasses.
