The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization-maintaining optical fiber link...The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization-maintaining optical fiber links the sensor head to the source and detection system, in which the technique of phase shift cancellation is used to cancel the phase shift that accumulatein the optical fiber. Flux concentrators were exploited to enhance the YIG crystal magneto-optic sensitivity .The sensor system exhibited a noise-equivalent field of 8 pT/√Hz and a 3 dB bandwidth of ~10 MHz.展开更多
Spiky spherical nickel powder with sharp nano-tips on its surface is a kind of excellent fillers for developing pressure-sensitive cement-based composites/sensors for traffic detection,structural health monitoring,and...Spiky spherical nickel powder with sharp nano-tips on its surface is a kind of excellent fillers for developing pressure-sensitive cement-based composites/sensors for traffic detection,structural health monitoring,and border and military security.The sharp nano-tips on the surface of spiky spherical nickel particles can induce field emission and tunneling effects,which leads to the ultrahigh pressure-sensitive responses of the cement-based composites.In this paper,we systematically introduce research on nanotip-induced ultrahigh pressure-sensitive cement-based composites/sensors,with attentions to their pressure-sensitive property and sensing mechanism,pressure-sensitive characteristic model,and smart structure system for traffic detection.展开更多
Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral biosensors.However,the intrinsic Ohmic loss in...Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral biosensors.However,the intrinsic Ohmic loss in surface plasmonic resonance has limited their practical use,resulting in large light dissipation and weak chiroptical resonance.Here,we report on the development of high-performance dielectric chiral shells(DCS)through a two-step Si deposition process on a self-assembled microsphere monolayer.The form DCS sample completely oyercomes the cancelation effect originated from the disorder property of the micro-sphere monolayer in macroscale,and at a wavelength of approximately 710 nm,the measured optimal chiral signal(g-factor)and transmittance can reach up to 0.7 and 0.3,respectively.The strong chiroptical effect comes from the asymmetric circular displacement currents(i.e.,magnetic modes)enabled by the specific shell geometry.The chiral shell geometry,electromagnetic properties,sensor sensitivity of chiral molecules and figure of merit are systematically investigated.The DCSs demonstrate highly sensitive detection of chiral biomolecules owing to their easily accessible geometry and enhanced uniform chiral field.展开更多
A magnetic field sensor based on nano-polysilicon thin films transistors(TFTs) with Hall probes is proposed.The magnetic field sensors are fabricated on <100> orientation high resistivity(ρ>500Ω·cm) si...A magnetic field sensor based on nano-polysilicon thin films transistors(TFTs) with Hall probes is proposed.The magnetic field sensors are fabricated on <100> orientation high resistivity(ρ>500Ω·cm) silicon substrates by using CMOS technology,which adopt nano-polysilicon thin films with thicknesses of 90 nm and heterojunction interfaces between the nano-polysilicon thin films and the high resistivity silicon substrates as the sensing layers.The experimental results show that when V_(DS) = 5.0 V,the magnetic sensitivities of magnetic field sensors based on nano-polysilicon TFTs with length-width ratios of 160μm/80μm,320μm/80μm and 480μm/80μm are 78 mV/T,55 mV/T and 34 mV/T,respectively.Under the same conditions,the magnetic sensitivity of the obtained magnetic field sensor is significantly improved in comparison with a Hall magnetic field sensor adopting silicon as the sensing layers.展开更多
For breaking through the sensitivity limitation of conventional surface plasmon resonance (SPR) biosensors, novel highly sensitive SPR biosensors with Au nanopartieles and nanogratings enhancement have been proposed...For breaking through the sensitivity limitation of conventional surface plasmon resonance (SPR) biosensors, novel highly sensitive SPR biosensors with Au nanopartieles and nanogratings enhancement have been proposed recently. But in practice, these structures have obvious disadvantages. In this study, a nanohole based sensitivity enhancement SPR biosensor is proposed and the influence of different structural parame- ters on the performance is investigated by using rigorous coupled wave analysis (RCWA). Electromagnetic field distributions around the nanohole are also given out to directly explain the performance difference for various structural parameters. The results indicate that significant sensitivity increase is associated with localized surface plasmons (LSPs) excitation mediated by nanoholes. Except to outcome the weakness of other LSP based biosensors, larger resonance angle shift, reflectance amplitude, and sharper SPR curves' width are obtained simultaneously under optimized structural parameters.展开更多
A large giant magneto-impedance effect was observed in CoFeSiB amorphous ribbon which was treated with the longitudinal field annealing in an atmosphere of Ar for one hour at 10-3 T and 400 ℃. The maximum magneto-imp...A large giant magneto-impedance effect was observed in CoFeSiB amorphous ribbon which was treated with the longitudinal field annealing in an atmosphere of Ar for one hour at 10-3 T and 400 ℃. The maximum magneto-impedance ratio is 475% and magnetic sensitivity of about 120%/Oe (1 Oe=80 A/m) at 20MHz, which is helpful to improve the sensitivity of magnetic sensor. The performances of the sensor were carefully studied in open-loop and closed-loop with negative feedback. The full measurement range of the magnetic field detection is 1.7-4 Oe presently, and the sensitivity achieves 176 mV/Oe. The sensor with negative feedback shows excellent linearity and good stability. The designed magnetic sensor can be applied in geomagnetic field measurement.展开更多
文摘The principle and performance of a fiber-optic Faraday-effect magnetic-field sensor based on an yttrium iron garnet (YIG) and two flux concentrations are described. A single polarization-maintaining optical fiber links the sensor head to the source and detection system, in which the technique of phase shift cancellation is used to cancel the phase shift that accumulatein the optical fiber. Flux concentrators were exploited to enhance the YIG crystal magneto-optic sensitivity .The sensor system exhibited a noise-equivalent field of 8 pT/√Hz and a 3 dB bandwidth of ~10 MHz.
文摘Spiky spherical nickel powder with sharp nano-tips on its surface is a kind of excellent fillers for developing pressure-sensitive cement-based composites/sensors for traffic detection,structural health monitoring,and border and military security.The sharp nano-tips on the surface of spiky spherical nickel particles can induce field emission and tunneling effects,which leads to the ultrahigh pressure-sensitive responses of the cement-based composites.In this paper,we systematically introduce research on nanotip-induced ultrahigh pressure-sensitive cement-based composites/sensors,with attentions to their pressure-sensitive property and sensing mechanism,pressure-sensitive characteristic model,and smart structure system for traffic detection.
基金financially supported by the National Natural Science Foundation of China(No.11604227)International Visiting Program for Excellent Young Scholars of SCU(No.20181504)International Science and Technology Innovation Cooperation of Sichuan Province(No.21GJHZ0230)。
文摘Chiral metamaterials have been a topic of significant research interest in recent years due to their potential for various applications in nanophotonic devices and chiral biosensors.However,the intrinsic Ohmic loss in surface plasmonic resonance has limited their practical use,resulting in large light dissipation and weak chiroptical resonance.Here,we report on the development of high-performance dielectric chiral shells(DCS)through a two-step Si deposition process on a self-assembled microsphere monolayer.The form DCS sample completely oyercomes the cancelation effect originated from the disorder property of the micro-sphere monolayer in macroscale,and at a wavelength of approximately 710 nm,the measured optimal chiral signal(g-factor)and transmittance can reach up to 0.7 and 0.3,respectively.The strong chiroptical effect comes from the asymmetric circular displacement currents(i.e.,magnetic modes)enabled by the specific shell geometry.The chiral shell geometry,electromagnetic properties,sensor sensitivity of chiral molecules and figure of merit are systematically investigated.The DCSs demonstrate highly sensitive detection of chiral biomolecules owing to their easily accessible geometry and enhanced uniform chiral field.
基金supported by the National Natural Science Foundation of China(No.61006057)the Foundation for University Young Key Teacher of Heilongjiang Province,China(No.1251G046)the Excellent Youth Foundation of Heilongjiang University,China(No.JCL201007)
文摘A magnetic field sensor based on nano-polysilicon thin films transistors(TFTs) with Hall probes is proposed.The magnetic field sensors are fabricated on <100> orientation high resistivity(ρ>500Ω·cm) silicon substrates by using CMOS technology,which adopt nano-polysilicon thin films with thicknesses of 90 nm and heterojunction interfaces between the nano-polysilicon thin films and the high resistivity silicon substrates as the sensing layers.The experimental results show that when V_(DS) = 5.0 V,the magnetic sensitivities of magnetic field sensors based on nano-polysilicon TFTs with length-width ratios of 160μm/80μm,320μm/80μm and 480μm/80μm are 78 mV/T,55 mV/T and 34 mV/T,respectively.Under the same conditions,the magnetic sensitivity of the obtained magnetic field sensor is significantly improved in comparison with a Hall magnetic field sensor adopting silicon as the sensing layers.
基金the Nanotechnology Pro-grams of Science and Technology Commission of Shang-hai Municipality under Grant No.0652nm004.
文摘For breaking through the sensitivity limitation of conventional surface plasmon resonance (SPR) biosensors, novel highly sensitive SPR biosensors with Au nanopartieles and nanogratings enhancement have been proposed recently. But in practice, these structures have obvious disadvantages. In this study, a nanohole based sensitivity enhancement SPR biosensor is proposed and the influence of different structural parame- ters on the performance is investigated by using rigorous coupled wave analysis (RCWA). Electromagnetic field distributions around the nanohole are also given out to directly explain the performance difference for various structural parameters. The results indicate that significant sensitivity increase is associated with localized surface plasmons (LSPs) excitation mediated by nanoholes. Except to outcome the weakness of other LSP based biosensors, larger resonance angle shift, reflectance amplitude, and sharper SPR curves' width are obtained simultaneously under optimized structural parameters.
文摘A large giant magneto-impedance effect was observed in CoFeSiB amorphous ribbon which was treated with the longitudinal field annealing in an atmosphere of Ar for one hour at 10-3 T and 400 ℃. The maximum magneto-impedance ratio is 475% and magnetic sensitivity of about 120%/Oe (1 Oe=80 A/m) at 20MHz, which is helpful to improve the sensitivity of magnetic sensor. The performances of the sensor were carefully studied in open-loop and closed-loop with negative feedback. The full measurement range of the magnetic field detection is 1.7-4 Oe presently, and the sensitivity achieves 176 mV/Oe. The sensor with negative feedback shows excellent linearity and good stability. The designed magnetic sensor can be applied in geomagnetic field measurement.