It is hard to simultaneously realize the high dielectric tunability and low loss for the single Ba_(0.6)Sr_(0.4)TiO_(3)(BST)dielectric film made through chemical method.Garnet structured Y_(2.80)Pr_(0.20)Fe_(5)O_(12)(...It is hard to simultaneously realize the high dielectric tunability and low loss for the single Ba_(0.6)Sr_(0.4)TiO_(3)(BST)dielectric film made through chemical method.Garnet structured Y_(2.80)Pr_(0.20)Fe_(5)O_(12)(YPrIG)ex-hibits the merits of high saturation magnetization and a much high resistivity,which are helpful for realizing magnetoelectric double tuning and suppressing the dielectric loss of BST film.In this work,Y_(2.80)Pr_(0.20)Fe_(5)O_(12)/Ba_(0.6)Sr_(0.4)TiO_(3)(YPrIG/BST)composite films were fabricated by sol-gel method.The com-posite films exhibited a low dielectric loss(0.0087),and got a magnetic tunability of 11.73%at 10 kOe and 1.44 MHz.Compared with BST film,the tunability of YPrIG/BST film was enhanced from 56.25%to 73.24%under the bias electric field of 800 kV/cm.Additionally,YPrIG/BST films exhibited an electromag-netic double adjustability.The electromagnetic tunability of YPrIG/BST composite films was as high as 80.40%at 1.44 MHz,under the DC bias electric field of 800 kV/cm and magnetic field of 10 kOe.This phenomenon can be explained in terms of the superposition effect of electric field and magnetic field.展开更多
A wide terahertz tuning range from 0.96 THz to 7.01 THz has been demonstrated based on ring-cavity THz wave parametric oscillator with a KTiOPO_(4)(KTP)crystal.The tuning range was observed intermittently from 0.96 TH...A wide terahertz tuning range from 0.96 THz to 7.01 THz has been demonstrated based on ring-cavity THz wave parametric oscillator with a KTiOPO_(4)(KTP)crystal.The tuning range was observed intermittently from 0.96 THz to 1.87 THz,from 3.04 THz to 3.33 THz,from 4.17 THz to 4.48 THz,from 4.78 THz to 4.97 THz,from 5.125 THz to 5.168 THz,from5.44 THz to 5.97 THz,and from 6.74 THz to 7.01 THz.The dual-Stokes wavelengths resonance phenomena were observed in some certain tuning angle ranges.Through the theoretical analysis of the dispersion curve of the KTP crystal,the intermittent THz wave tuning range and dual-wavelength Stokes waves operation during angle tuning process were explained.The theoretical analysis was in good agreement with the experiment results.The maximum THz output voltage detected by Golay cell was 1.7 V at 5.7 THz under the pump energy of 210 mJ,corresponding to the THz wave output energy of5.47μJ and conversion efficiency of 2.6×10^(-5).展开更多
The optical properties of cylindrical core–shell nanorods(CCSNs)are theoretically investigated in this paper.The results show that Fano resonance can be generated in CCSNs,and the wavelength and the intensity at Fano...The optical properties of cylindrical core–shell nanorods(CCSNs)are theoretically investigated in this paper.The results show that Fano resonance can be generated in CCSNs,and the wavelength and the intensity at Fano dip can be tuned respectively by adjusting the field coupling of cavity mode inside and near field on gold surface.The high tuning sensitivity which is about 400 nm per refractive-index unit can be obtained,and an easy-to-realize tunable parameter is also proposed.A two-oscillator model is also introduced to describe the generation of Fano resonance in CCSNs,and the results from this model are in good agreement with theoretical results.The CCSNs investigated in this work may have promising applications in optical devices.展开更多
A composite ceramic with nominal composition of 45.0 wt%（Ba0.5Sr0.5）TiO3–55.0 wt%MgO（acronym is BST–MgO） is sintered for fabricating a frequency reconfigurable aperture-coupled microstrip antenna. The calcined ...A composite ceramic with nominal composition of 45.0 wt%（Ba0.5Sr0.5）TiO3–55.0 wt%MgO（acronym is BST–MgO） is sintered for fabricating a frequency reconfigurable aperture-coupled microstrip antenna. The calcined BST–Mg O composite ceramic exhibits good microwave dielectric properties at X-band with appropriate dielectric constant εr around85, lower dielectric loss tan δ about 0.01, and higher permittivity tunability 14.8% at 8.33 k V/cm. An ultrahigh E-field tunability of working frequency up to 11.0%（i.e., from 9.1 GHz to 10.1 GHz with a large frequency shift of 1000 MHz）at a DC bias field from 0 to 8.33 k V/cm and a considerably large center gain over 7.5 d B are obtained in the designed frequency reconfigurable microstrip antenna. These results demonstrate that BST materials are promising for the frequency reconfigurable antenna.展开更多
The electric-field tunability of dielectric constant （ε-E） in Sr1-xMnxTiO3 films （x = 0, 0.005, 0.010, 0.020 and 0.030） prepared by the metal organic decomposition method on Pt/Ti/SiO2/Si substrates is studied in...The electric-field tunability of dielectric constant （ε-E） in Sr1-xMnxTiO3 films （x = 0, 0.005, 0.010, 0.020 and 0.030） prepared by the metal organic decomposition method on Pt/Ti/SiO2/Si substrates is studied in the frequency range from 100Hz to 1MHz with different Mn contents at different temperatures. The frequencyindependent tunability increases strongly with decreasing the temperature from 300 K to 150K. The tunability （-31%） in thin films （x = 0.005） at 150K is obtained and the temperature for the same tunability in ceramics is about 60 K lower than the present one. This tunability is comparable with that in one of ferroelectric Sr1-1.sxBixTiO3 thin films. Similarly, the well-defined P（E） hysteresis 10013 and 2Pr （1.2 μC/cm^2） can be obtained at 300 K in Sr1-xMnxTiO3 films with z = 0.005. Both the existence of electric dipole or poled micro domain introduced by the doped Mn2＋ located in the off-center position at Sr sites and the strain between the thin film and the substrate are the origins of the tunable and polar behavior in Sr1-xMnxTiO3 films.展开更多
We report a direct blue-diode-pumped wavelength tunable Kerr-lens mode-locked Ti: sapphire laser.Central wavelength tunability as broad as 89 nm(736-825 nm) is achieved by adjusting the insertion of the prism.Pulses a...We report a direct blue-diode-pumped wavelength tunable Kerr-lens mode-locked Ti: sapphire laser.Central wavelength tunability as broad as 89 nm(736-825 nm) is achieved by adjusting the insertion of the prism.Pulses as short as 17 fs are generated at a central wavelength of 736 nm with an average output power of 31 mW.The maximum output power is 46.8 mW at a central wavelength of 797 nm with a pulse duration of 46 fs.展开更多
Y_(2.80)Pr_(0.20)Fe_(5)O_(12)/Ba_(0.6)Sr_(0.4)TiO_(3)thin film heterostructure was claimed by Jiao et al.in Journal of Materials Science&Technology 202(2024)174 as a tunable dielectric material with superior perfo...Y_(2.80)Pr_(0.20)Fe_(5)O_(12)/Ba_(0.6)Sr_(0.4)TiO_(3)thin film heterostructure was claimed by Jiao et al.in Journal of Materials Science&Technology 202(2024)174 as a tunable dielectric material with superior performance achieved under simultaneous application of the electric and magnetic fields at a particular frequency of 1.44 MHz.However,here we express concerns regarding the real presence of the phenomenon at 1.44 MHz in the studied structures based on the literature and dielectric spectroscopy principles.We also note that the presented dielectric results and their interpretations are contradictory.展开更多
We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with du...We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.展开更多
Eutectogels are considered to have immense application potential in the field of flexible wearable ionotronic devices because of their excellent ionic conductivity,thermal and electrochemical stability,and non-volatil...Eutectogels are considered to have immense application potential in the field of flexible wearable ionotronic devices because of their excellent ionic conductivity,thermal and electrochemical stability,and non-volatility.However,most existing technologies still struggle to achieve synergistic optimization of key performance indicators,such as high mechanical strength and ionic conductivity.To address this chal-lenge,this study successfully prepared a green eutectogel material with outstanding comprehensive properties by leveraging the high solubility of glycerol in a polymerizable deep eutectic solvent(DES)composed of acrylic acid and choline chloride.The resulting eutectogels exhibited a high transparency(89%),high mechanical strength(up to 2.8 MPa),and exceptional tensile performance(up to 1385%).The fabricated flexible sensor demonstrated ideal linear sensitivity(gauge factor:0.88),a broad response range(1%-100%),and reliable stability(over 1000 cycles),en-abling the precise monitoring of human motion(e.g.,finger bending and wrist rotation).The flexible strain sensor based on this eutectogel is ex-pected to show promising prospects for medical monitoring,human-machine interaction,and industrial sensing applications.展开更多
Reconfigurable metamaterials significantly expand the application scenarios and operating frequency range of metamaterials,making them promising candidates for use in smart tunable device.Here,we propose and experimen...Reconfigurable metamaterials significantly expand the application scenarios and operating frequency range of metamaterials,making them promising candidates for use in smart tunable device.Here,we propose and experimentally demonstrate that integrating metamaterial design principles with the intrinsic features of natural materials can engineer thermal smart metadevices.Tunable extraordinary optical transmission like(EOT-like)phenomena have been achieved in the microwave regime using shape memory alloy(SMA).The strongly localized fields generated by designed metadevices,combined with the intense interference of incident waves,enhance transmission through subwavelength apertures.Leveraging the temperature-responsive properties of SMA,the morphology of the metadevice can be recontructed,thereby modifying its response to electromagnetic waves.The experiments demonstrated control over the operating frequency and transmission amplitude of EOT-like behavior,achieving a maximum transmission enhancement factor of 126.Furthermore,the metadevices with modular design enable the realization of multiple functions with independent control have been demonstrated.The proposed SMA-based metamaterials offer advantages in terms of miniaturization,easy processing,and high design flexibility.They may have potential applications in microwave devices requiring temperature control,such as sensing and monitoring.展开更多
We suggest a low cross-talk plasmonic cross-connector based on a metal/insulator/metal cavity and waveguides.We separately investigate the isolated cavity mode, the waveguide mode, and the combination of cavity and wa...We suggest a low cross-talk plasmonic cross-connector based on a metal/insulator/metal cavity and waveguides.We separately investigate the isolated cavity mode, the waveguide mode, and the combination of cavity and waveguide modes using a finite-different time-domain method. Due to resonant tunneling and the cutoff frequency of the odd waveguide mode, our proposed structure achieves a high throughput transmission ratio and eliminates cross-talk. Furthermore, the proposed structure has a broadband tunability of 587 nm, which can be achieved by modulating the cavity air gap thickness. This structure enables the miniaturization of photonic integrated circuits and sensing applications.展开更多
Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectr...Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectronic integration,but still faces serious challenges.Herein,we propose a facile method to synthesize cesium lead halide(CsPbX3)microstructures with well-defined morphologies,sizes,and constituent element gradient.The scheme is conducted using a chemical vapor deposition(CVD),which is subsequently associated with annealing-assisted solid-solid anion exchange.For the plate-shaped structures,the controllability on the cross-sectional dimension enables to precisely modulate the lasing modes,thus achieving single-mode operation;while tuning the stoichiometric of the halogen anion components in the plate-shaped CsPbI_(x)Br_(3−x) alloy samples,the lasing wavelengths are straightforwardly varied to span the entire visible spectrum.By comparison,the experimental scheme on synthesizing alloyed CsPbI_(x)Br_(3−x) perovskites is conducted using an in-situ approach,thereby achieving precise modulation of bandgap-controlled microlasers by controlling the reaction time.Such laser properties like controllable microcavity modes and broad stoichiometry-dependent tunability of light-emitting/lasing colors,associated with the facile synthesizing method of monocrystalline CsPbI_(x)Br_(3−x) structures,make lead halide perovskites ideal materials for the development of wavelength-controlled microlasers toward practical photonic integration.展开更多
Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz ba...Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.展开更多
Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated thr...Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated through depositing ZnO on patterned silicon on an insulator(SOI)substrate.The cavity structure,morphology,and photoluminescence(PL)properties are studied systematically.The cavity shows a well-defined circular structure with oxygen vacancies.Under the synergistic action of surface tension and stress,the ZnO microdisk shows a unique toroid structure with a high sidewall surface finish.The ZnO microcavity(8μm in diameter)shows optically pumped whispering gallery modes(WGMs)lasing in the ultraviolet region with a Q factor exceeding 1300.More interestingly,the quality of the toroid ZnO microdisk cavity is high enough to support the bandgap renormalization(BGR)phenomenon.With the increasing pumping power,the lasing spectra will be modulated.The lasing spectrum undergoes a Burstein-Moss(BM)effect-induced blueshift and an electron-hole plasma(EHP)effect-induced redshift.展开更多
MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-moldi...MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-molding a flexible substrate,or regulating the micromorphology of MXene sheets,to obtain a micro-structured surface.However,the two avenues usually require complicated and time-consuming microfabrication or wet chemical processing,and are limited to non-adjustable topographicelectrical(topo-electro)properties.Herein,we propose a lithographic printing inspired in-situ transfer(LIPIT)strategy to fabricate MXene-ink films(MIFs).In LIPIT,MIFs not only inherit ridge-and-valley microstructure from paper substrate,but also achieve localized topo-electro tunability by programming ink-writing patterns and cycles.The MIF-based flexible pressure sensor with periodical topo-electro gradient exhibits remarkably boosted sensitivity in a wide sensing range(low detection limit of 0.29 Pa and working range of 100 kPa).The MIF sensor demonstrates versatile applicability in both subtle and vigorous pressuresensing fields,ranging from pulse wave extraction and machine learning-assisted surface texture recognition to piano-training glove(PT-glove)for piano learning.The LIPIT is quick,low-cost,and compatible with free ink/substrate combinations,which promises a versatile toolbox for designing functional MXene films with tailored morphological-mechanical-electrical properties for extended application scenarios.展开更多
All-inorganic zero-dimensional(0D)tetrahedrite(Cu12Sb4S13,CAS)quantum dots(QDs)have attracted extensive attention due to their excellent optical properties,bandgap tunability,and carrier mobility.In this paper,various...All-inorganic zero-dimensional(0D)tetrahedrite(Cu12Sb4S13,CAS)quantum dots(QDs)have attracted extensive attention due to their excellent optical properties,bandgap tunability,and carrier mobility.In this paper,various sized CAS QDs(5.1,6.7,and 7.9 nm)are applied as a switching layer with the structure F:Sn O2(FTO)/CAS QDs/Au,and in doing so,the nonvolatile resistive-switching behavior of electronics based on CAS QDs is reported.The SET/RESET voltage tunability with size dependency is observed for memory devices based on CAS QDs for the first time.Results suggest that differently sized CAS QDs result in different band structures and the regulation of the SET/RESET voltage occurs simply and effectively due to the uniform size of the CAS QDs.Moreover,the presented memory devices have reliable bipolar resistive-switching properties,a resistance(ON/OFF)ratio larger than 104,high reproducibility,and good data retention ability.After 1.4×10^6s of stability testing and 104cycles of quick read tests,the change rate of the ON/OFF ratio is smaller than 0.1%.Furthermore,resistiveswitching stability can be improved by ensuring a uniform particle size for the CAS QDs.The theoretical calculations suggest that the space-charge-limited currents(SCLCs),which are functioned by Cu 3d,Cu 3p and S 3p to act as electron selftrapping centers due to their quantum confinement and form conduction pathways under an electric field,are responsible for the resistive-switching effect.This paper demonstrates that CAS QDs are promising as a novel resistive-switching material in memory devices and can be used to facilitate the application of next-generation nonvolatile memory.展开更多
Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating...Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.展开更多
Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex...Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.展开更多
Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on ...Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on the fact that a variational reversible locally resonant elastic metamaterial(LREM) with four configurations is proposed. Through a combination of theoretical analysis and numerical simulations, this newly designed metamaterial is proven to exhibit different bandgap ranges and vibration attenuation properties in each configuration. Especially, there is tunable anisotropy shown in these configurations, which enables the bandgaps in two directions to be separated or overlapped. A model with a bandgap shifting ratio(BSR) of 100% and an overlap ratio of 25% is set to validate the multistable strategy feasibility. The proposed design strategy demonstrates significant potentials for applications in versatile scenarios.展开更多
In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature o...In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature of VO_(2),the design can realize active tuning of the plasmon induced transparency(PIT)effect at terahertz frequency,thereby converting from a single PIT to a double-PIT.When VO_(2) is in the insulating state,the structure is symmetric to obtain a single-band PIT effect.When VO_(2) is in the metallic state,the structure turns asymmetric to realize a dual-band PIT effect.This design provides a reference direction for the design of actively tunable metamaterials.Additionally,it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship.In addition,the structure achieves superior refractive index sensitivity in the terahertz band,surpassing 1 THz/RIU.Consequently,the design exhibits encouraging potential for application in refractive index sensors and optical switches.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52171191,52371198)Shaanxi Key Program for International Science and Technology Coopera-tion Projects(No.2021KWZ-12)the Youth Innovation Team of Shaanxi Universities.
文摘It is hard to simultaneously realize the high dielectric tunability and low loss for the single Ba_(0.6)Sr_(0.4)TiO_(3)(BST)dielectric film made through chemical method.Garnet structured Y_(2.80)Pr_(0.20)Fe_(5)O_(12)(YPrIG)ex-hibits the merits of high saturation magnetization and a much high resistivity,which are helpful for realizing magnetoelectric double tuning and suppressing the dielectric loss of BST film.In this work,Y_(2.80)Pr_(0.20)Fe_(5)O_(12)/Ba_(0.6)Sr_(0.4)TiO_(3)(YPrIG/BST)composite films were fabricated by sol-gel method.The com-posite films exhibited a low dielectric loss(0.0087),and got a magnetic tunability of 11.73%at 10 kOe and 1.44 MHz.Compared with BST film,the tunability of YPrIG/BST film was enhanced from 56.25%to 73.24%under the bias electric field of 800 kV/cm.Additionally,YPrIG/BST films exhibited an electromag-netic double adjustability.The electromagnetic tunability of YPrIG/BST composite films was as high as 80.40%at 1.44 MHz,under the DC bias electric field of 800 kV/cm and magnetic field of 10 kOe.This phenomenon can be explained in terms of the superposition effect of electric field and magnetic field.
基金Project supported by the National Basic Research Program of China(Grant Nos.2015CB755403 and 2014CB339802)the National Key Research and Development Program of China(Grant No.2016YFC0101001)+2 种基金the National Natural Science Foundation of China(Grant Nos.61775160,61771332,and 61471257)China Postdoctoral Science Foundation(Grant No.2016M602954)Postdoctoral Science Foundation of Chongqing,China(Grant No.Xm2016021)
文摘A wide terahertz tuning range from 0.96 THz to 7.01 THz has been demonstrated based on ring-cavity THz wave parametric oscillator with a KTiOPO_(4)(KTP)crystal.The tuning range was observed intermittently from 0.96 THz to 1.87 THz,from 3.04 THz to 3.33 THz,from 4.17 THz to 4.48 THz,from 4.78 THz to 4.97 THz,from 5.125 THz to 5.168 THz,from5.44 THz to 5.97 THz,and from 6.74 THz to 7.01 THz.The dual-Stokes wavelengths resonance phenomena were observed in some certain tuning angle ranges.Through the theoretical analysis of the dispersion curve of the KTP crystal,the intermittent THz wave tuning range and dual-wavelength Stokes waves operation during angle tuning process were explained.The theoretical analysis was in good agreement with the experiment results.The maximum THz output voltage detected by Golay cell was 1.7 V at 5.7 THz under the pump energy of 210 mJ,corresponding to the THz wave output energy of5.47μJ and conversion efficiency of 2.6×10^(-5).
基金Project supported by the National Natural Science Foundation of China(Grant No.11647021)。
文摘The optical properties of cylindrical core–shell nanorods(CCSNs)are theoretically investigated in this paper.The results show that Fano resonance can be generated in CCSNs,and the wavelength and the intensity at Fano dip can be tuned respectively by adjusting the field coupling of cavity mode inside and near field on gold surface.The high tuning sensitivity which is about 400 nm per refractive-index unit can be obtained,and an easy-to-realize tunable parameter is also proposed.A two-oscillator model is also introduced to describe the generation of Fano resonance in CCSNs,and the results from this model are in good agreement with theoretical results.The CCSNs investigated in this work may have promising applications in optical devices.
基金Project supported by the National Natural Science Foundation of China(Grant No.11074040)the Key Project of Shandong Provincial Department of Science and TechnologyChina(Grant No.ZR2012FZ006)
文摘A composite ceramic with nominal composition of 45.0 wt%（Ba0.5Sr0.5）TiO3–55.0 wt%MgO（acronym is BST–MgO） is sintered for fabricating a frequency reconfigurable aperture-coupled microstrip antenna. The calcined BST–Mg O composite ceramic exhibits good microwave dielectric properties at X-band with appropriate dielectric constant εr around85, lower dielectric loss tan δ about 0.01, and higher permittivity tunability 14.8% at 8.33 k V/cm. An ultrahigh E-field tunability of working frequency up to 11.0%（i.e., from 9.1 GHz to 10.1 GHz with a large frequency shift of 1000 MHz）at a DC bias field from 0 to 8.33 k V/cm and a considerably large center gain over 7.5 d B are obtained in the designed frequency reconfigurable microstrip antenna. These results demonstrate that BST materials are promising for the frequency reconfigurable antenna.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51225201,61271078,and 51102133the National Basic Research Program of China under Grant No 2015CB921201+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Fundamental Research Funds for the Central Universities
文摘The electric-field tunability of dielectric constant （ε-E） in Sr1-xMnxTiO3 films （x = 0, 0.005, 0.010, 0.020 and 0.030） prepared by the metal organic decomposition method on Pt/Ti/SiO2/Si substrates is studied in the frequency range from 100Hz to 1MHz with different Mn contents at different temperatures. The frequencyindependent tunability increases strongly with decreasing the temperature from 300 K to 150K. The tunability （-31%） in thin films （x = 0.005） at 150K is obtained and the temperature for the same tunability in ceramics is about 60 K lower than the present one. This tunability is comparable with that in one of ferroelectric Sr1-1.sxBixTiO3 thin films. Similarly, the well-defined P（E） hysteresis 10013 and 2Pr （1.2 μC/cm^2） can be obtained at 300 K in Sr1-xMnxTiO3 films with z = 0.005. Both the existence of electric dipole or poled micro domain introduced by the doped Mn2＋ located in the off-center position at Sr sites and the strain between the thin film and the substrate are the origins of the tunable and polar behavior in Sr1-xMnxTiO3 films.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFB0402105)
文摘We report a direct blue-diode-pumped wavelength tunable Kerr-lens mode-locked Ti: sapphire laser.Central wavelength tunability as broad as 89 nm(736-825 nm) is achieved by adjusting the insertion of the prism.Pulses as short as 17 fs are generated at a central wavelength of 736 nm with an average output power of 31 mW.The maximum output power is 46.8 mW at a central wavelength of 797 nm with a pulse duration of 46 fs.
基金the FCT/MEC(PIDDAC)within FCT independent researcher grant 2021.02284.CEECIND/CP1659/CT0018(DOI 10.54499/2021.02284.CEECIND/CP1659/CT0018)+1 种基金supported by national funds,through FCT in the scope of the framework contract foreseen in numbers 4,5,and 6 of article 23 of the Decree Law 57/2016,of 29 August,UIDB/00481/2020 and UIDP/00481/2020,DOI 10.54499/UIDB/00481/2020 and DOI 10.54499/UIDP/00481/2020CENTRO-01-0145-FEDER-022083-Centro Portugal Regional Operational Programme(Centro2020),under the PORTUGAL 2020 Partnership Agreement,through the European Regional Develop-ment Fund.
文摘Y_(2.80)Pr_(0.20)Fe_(5)O_(12)/Ba_(0.6)Sr_(0.4)TiO_(3)thin film heterostructure was claimed by Jiao et al.in Journal of Materials Science&Technology 202(2024)174 as a tunable dielectric material with superior performance achieved under simultaneous application of the electric and magnetic fields at a particular frequency of 1.44 MHz.However,here we express concerns regarding the real presence of the phenomenon at 1.44 MHz in the studied structures based on the literature and dielectric spectroscopy principles.We also note that the presented dielectric results and their interpretations are contradictory.
基金supported by the National Natural Science Foundation of China(Grant Nos.12192251,12334014,12404378,92480001,12134001,12174113,12174107,12474325,12404379,and 12474378)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301403)+1 种基金Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX01)Fundamental Research Funds for the Central Universities,the Engineering Research Center for Nanophotonics&Advanced Instrument,Ministry of Education,East China Normal University(Grant No.2023nmc005).
文摘We present a compact optical delay line(ODL)with wide-range continuous tunability on thin-film lithium niobate platform.The proposed device integrates an unbalanced Mach-Zehnder interferometer(MZI)architecture with dual tunable couplers,where each coupler comprises two 2×2 multimode interferometers and a MZI phase-tuning section.Experimental results demonstrate continuous delay tuning from 0 to 293 ps through synchronized control of coupling coefficients,corresponding to a 4 cm path difference between interferometer arms.The measured delay range exhibits excellent agreement with theoretical predictions derived from ODL waveguide parameters.This result addresses critical challenges in integrated photonic systems that require precise temporal control,particularly for applications in optical communications and quantum information processing,where a wide tuning range is paramount.
基金supported by the National Natural Science Foundation of China(Nos.22301037, 22401045)the Natural Science Foundation of Guangdong Province(No.2022A1515110867).
文摘Eutectogels are considered to have immense application potential in the field of flexible wearable ionotronic devices because of their excellent ionic conductivity,thermal and electrochemical stability,and non-volatility.However,most existing technologies still struggle to achieve synergistic optimization of key performance indicators,such as high mechanical strength and ionic conductivity.To address this chal-lenge,this study successfully prepared a green eutectogel material with outstanding comprehensive properties by leveraging the high solubility of glycerol in a polymerizable deep eutectic solvent(DES)composed of acrylic acid and choline chloride.The resulting eutectogels exhibited a high transparency(89%),high mechanical strength(up to 2.8 MPa),and exceptional tensile performance(up to 1385%).The fabricated flexible sensor demonstrated ideal linear sensitivity(gauge factor:0.88),a broad response range(1%-100%),and reliable stability(over 1000 cycles),en-abling the precise monitoring of human motion(e.g.,finger bending and wrist rotation).The flexible strain sensor based on this eutectogel is ex-pected to show promising prospects for medical monitoring,human-machine interaction,and industrial sensing applications.
基金the financial support from the National Key R&D Program of China (Nos. 2023YFB3811400, 2022YFB3806000)the National Natural Science Foundation of China (Nos. 12074314, 52202370, 52332006)+3 种基金the Aeronautical Science Foundation of China (No. 20230018053007)the Science and Technology New Star Program of Shaanxi Province (No. 2023KJXX-148)the Fundamental Research Funds for the Central UniversitiesChina Postdoctoral Science Foundation (No. 2023T160359)
文摘Reconfigurable metamaterials significantly expand the application scenarios and operating frequency range of metamaterials,making them promising candidates for use in smart tunable device.Here,we propose and experimentally demonstrate that integrating metamaterial design principles with the intrinsic features of natural materials can engineer thermal smart metadevices.Tunable extraordinary optical transmission like(EOT-like)phenomena have been achieved in the microwave regime using shape memory alloy(SMA).The strongly localized fields generated by designed metadevices,combined with the intense interference of incident waves,enhance transmission through subwavelength apertures.Leveraging the temperature-responsive properties of SMA,the morphology of the metadevice can be recontructed,thereby modifying its response to electromagnetic waves.The experiments demonstrated control over the operating frequency and transmission amplitude of EOT-like behavior,achieving a maximum transmission enhancement factor of 126.Furthermore,the metadevices with modular design enable the realization of multiple functions with independent control have been demonstrated.The proposed SMA-based metamaterials offer advantages in terms of miniaturization,easy processing,and high design flexibility.They may have potential applications in microwave devices requiring temperature control,such as sensing and monitoring.
基金National Research Foundation of Korea(NRF)(NRF-2015R1A2A1A15055998,NRF-2013M3C1A3065051,NRF-2016R1C1B2007007)
文摘We suggest a low cross-talk plasmonic cross-connector based on a metal/insulator/metal cavity and waveguides.We separately investigate the isolated cavity mode, the waveguide mode, and the combination of cavity and waveguide modes using a finite-different time-domain method. Due to resonant tunneling and the cutoff frequency of the odd waveguide mode, our proposed structure achieves a high throughput transmission ratio and eliminates cross-talk. Furthermore, the proposed structure has a broadband tunability of 587 nm, which can be achieved by modulating the cavity air gap thickness. This structure enables the miniaturization of photonic integrated circuits and sensing applications.
基金supported by the National Natural Science Foundation of China(No.12374257)。
文摘Development of on-chip coherent light sources with desired single-mode operation and straightforward spectral tunability has attracted intense interest due to ever-increasing demand for photonic devices and optoelectronic integration,but still faces serious challenges.Herein,we propose a facile method to synthesize cesium lead halide(CsPbX3)microstructures with well-defined morphologies,sizes,and constituent element gradient.The scheme is conducted using a chemical vapor deposition(CVD),which is subsequently associated with annealing-assisted solid-solid anion exchange.For the plate-shaped structures,the controllability on the cross-sectional dimension enables to precisely modulate the lasing modes,thus achieving single-mode operation;while tuning the stoichiometric of the halogen anion components in the plate-shaped CsPbI_(x)Br_(3−x) alloy samples,the lasing wavelengths are straightforwardly varied to span the entire visible spectrum.By comparison,the experimental scheme on synthesizing alloyed CsPbI_(x)Br_(3−x) perovskites is conducted using an in-situ approach,thereby achieving precise modulation of bandgap-controlled microlasers by controlling the reaction time.Such laser properties like controllable microcavity modes and broad stoichiometry-dependent tunability of light-emitting/lasing colors,associated with the facile synthesizing method of monocrystalline CsPbI_(x)Br_(3−x) structures,make lead halide perovskites ideal materials for the development of wavelength-controlled microlasers toward practical photonic integration.
文摘Multiple functional metasurfaces with high information capacity have attracted considerable attention from researchers.This study proposes a 2-bit tunable spin-decoupled coded metasurface designed for the terahertz band,which utilizes the tunable properties of Dirac semimetals(DSM)to create a novel multilayer structure.By incorporating both geometric and propagating phases into the metasurface design,we can effectively control the electromagnetic wave.When the Fermi level(EF)of the DSM is set at 6 meV,the electromagnetic wave is manipulated by the gold patch embedded in the DSM film,operating at a frequency of 1.3 THz.When the EF of the DSM is set at 80 meV,the electromagnetic wave is manipulated by the DSM patch,operating at a frequency of 1.4 THz.Both modes enable independent control of beam splitting under left-rotating circularly polarized(LCP)and rightrotating circularly polarized(RCP)wave excitation,resulting in the generation of vortex beams with distinct orbital angular momentum(OAM)modes.The findings of this study hold significant potential for enhancing information capacity and polarization multiplexing techniques in wireless communications.
文摘Although it has a significant advantage in gain properties,the lack of selective etching processes hinders ZnO lasing in on-chip applications.Herein,the circular ZnO microdisk pivoted on Si substrate is fabricated through depositing ZnO on patterned silicon on an insulator(SOI)substrate.The cavity structure,morphology,and photoluminescence(PL)properties are studied systematically.The cavity shows a well-defined circular structure with oxygen vacancies.Under the synergistic action of surface tension and stress,the ZnO microdisk shows a unique toroid structure with a high sidewall surface finish.The ZnO microcavity(8μm in diameter)shows optically pumped whispering gallery modes(WGMs)lasing in the ultraviolet region with a Q factor exceeding 1300.More interestingly,the quality of the toroid ZnO microdisk cavity is high enough to support the bandgap renormalization(BGR)phenomenon.With the increasing pumping power,the lasing spectra will be modulated.The lasing spectrum undergoes a Burstein-Moss(BM)effect-induced blueshift and an electron-hole plasma(EHP)effect-induced redshift.
基金supported by the National Natural Science Foundation of China(Nos.62122080,62261136551,and 52203365)the Natural Science Foundation of Shanghai(Nos.22ZR1481700 and 22dz1205000)the Shanghai Pujiang Program(No.21PJ1414800).
文摘MXene-based films have been intensively explored for construction of piezoresistive flexible pressure sensors owing to their excellent mechanical and electrical properties.High pressure sensitivity relies on pre-molding a flexible substrate,or regulating the micromorphology of MXene sheets,to obtain a micro-structured surface.However,the two avenues usually require complicated and time-consuming microfabrication or wet chemical processing,and are limited to non-adjustable topographicelectrical(topo-electro)properties.Herein,we propose a lithographic printing inspired in-situ transfer(LIPIT)strategy to fabricate MXene-ink films(MIFs).In LIPIT,MIFs not only inherit ridge-and-valley microstructure from paper substrate,but also achieve localized topo-electro tunability by programming ink-writing patterns and cycles.The MIF-based flexible pressure sensor with periodical topo-electro gradient exhibits remarkably boosted sensitivity in a wide sensing range(low detection limit of 0.29 Pa and working range of 100 kPa).The MIF sensor demonstrates versatile applicability in both subtle and vigorous pressuresensing fields,ranging from pulse wave extraction and machine learning-assisted surface texture recognition to piano-training glove(PT-glove)for piano learning.The LIPIT is quick,low-cost,and compatible with free ink/substrate combinations,which promises a versatile toolbox for designing functional MXene films with tailored morphological-mechanical-electrical properties for extended application scenarios.
基金supported by the National Natural Science Foundation of China(51572205,11674258 and 51802093)the Joint Fund of Ministry of Education for Equipment Pre-research the Fundamental Research(6141A02022262)+1 种基金the Excellent Dissertation Cultivation Funds of Wuhan University of Technology(2018-YS-001)the Fundamental Research Funds for the Central Universities(2019zy-007)。
文摘All-inorganic zero-dimensional(0D)tetrahedrite(Cu12Sb4S13,CAS)quantum dots(QDs)have attracted extensive attention due to their excellent optical properties,bandgap tunability,and carrier mobility.In this paper,various sized CAS QDs(5.1,6.7,and 7.9 nm)are applied as a switching layer with the structure F:Sn O2(FTO)/CAS QDs/Au,and in doing so,the nonvolatile resistive-switching behavior of electronics based on CAS QDs is reported.The SET/RESET voltage tunability with size dependency is observed for memory devices based on CAS QDs for the first time.Results suggest that differently sized CAS QDs result in different band structures and the regulation of the SET/RESET voltage occurs simply and effectively due to the uniform size of the CAS QDs.Moreover,the presented memory devices have reliable bipolar resistive-switching properties,a resistance(ON/OFF)ratio larger than 104,high reproducibility,and good data retention ability.After 1.4×10^6s of stability testing and 104cycles of quick read tests,the change rate of the ON/OFF ratio is smaller than 0.1%.Furthermore,resistiveswitching stability can be improved by ensuring a uniform particle size for the CAS QDs.The theoretical calculations suggest that the space-charge-limited currents(SCLCs),which are functioned by Cu 3d,Cu 3p and S 3p to act as electron selftrapping centers due to their quantum confinement and form conduction pathways under an electric field,are responsible for the resistive-switching effect.This paper demonstrates that CAS QDs are promising as a novel resistive-switching material in memory devices and can be used to facilitate the application of next-generation nonvolatile memory.
基金supported by the National Key Research and Development Program of China(No.2022YFC2805200)the National Natural Science Foundation of China(No.52373094)+4 种基金Zhejiang Provincial Natural Science Foundation(No.LR25E030004)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2023313)Sino-German Mobility Program(No.M-0424),Ningbo Major Research and Development Plan Project(No.20241ZDYF020148)Ningbo International Cooperation(No.2023H019)Ningbo Science&Technology Bureau(No.2024QL003)。
文摘Controllably tuning the sensing performance of flexible mechanical sensors is important for them to realize on-demand sensing of various mechanical stimuli in different application scenarios.However,current regulating strategies focus on the construction process of individual sensors,the response performance of the as-formed sensors is still hard to autonomously tune with external stimulus changes like human skin.Here,we propose a new strategy that realizes post-tuning of the sensing performance by introducing a temperature-dependent phase transition elastomer into the sensing film.Through an interfacially confined photopolymerization reaction,a graphene-based phase-transition elastomeric(GPTE)film with a robust interface and excellent conductivity is well-formed at the water/air interface.Benefiting from the crystallization-melt dynamic switching in the elastomer network,the GPTE film could experience the reversible transformation between soft(1.65 MPa)and stiff(12.27MPa)states,showing huge changes of elastic modulus up to seven times near the phase transition temperature(28.5℃).Furthermore,the GPTE film is designed into a suspended perceptual configuration realizing the dynamic detection of 3D deformation adapted to temperature changes with up to 3.5-fold difference in response sensitivity.Finally,the self-adaptive sensing behavior of temperature-mediated 3D deformation is demonstrated by the effective detection of the dynamic stimulation process of cold and hot water droplets by the GPTE suspended film.The proposed strategy of phase transition-induced post-tuning of sensing performance could greatly facilitate flexible mechanical sensors towards a more intelligent one.
基金supported by Jiangsu Special Project for Frontier Leading Base Technology(Grant Nos.BK20192004)Fundamental Research Funds for Central Universities(Grant Nos.B240201190)+3 种基金Changzhou Social Development Science and Technology Support Project(Grant Nos.CE20225037)Changzhou Science and Technology Project(Grant Nos.CM20223014)Suzhou Key Industrial Technology Innovation Forward-Looking Application Research Project(Grant Nos.SYG202143)Changzhou Science and Technology Project(Grant Nos.CJ20241061).
文摘Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.
基金supported by the National Natural Science Foundation of China(No.52192633)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2025JC-YBMS-050)。
文摘Metamaterials with multistability have attracted much attention due to their extraordinary physical properties. In this paper, we report a novel multistable strategy that is reversible under external forces, based on the fact that a variational reversible locally resonant elastic metamaterial(LREM) with four configurations is proposed. Through a combination of theoretical analysis and numerical simulations, this newly designed metamaterial is proven to exhibit different bandgap ranges and vibration attenuation properties in each configuration. Especially, there is tunable anisotropy shown in these configurations, which enables the bandgaps in two directions to be separated or overlapped. A model with a bandgap shifting ratio(BSR) of 100% and an overlap ratio of 25% is set to validate the multistable strategy feasibility. The proposed design strategy demonstrates significant potentials for applications in versatile scenarios.
基金supported by the Natural Science Foundation of Chongqing of China(No.CSTB2024NSCQ-MSX0746)the Young Scientists Fund of the National Natural Science Foundation of China(No.11704053)+1 种基金the National Natural Science Foundation of China(No.52175531)the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJQN 201800629,KJZD-M202000602 and 62375031)。
文摘In this paper,we present a metamaterial structure of Dirac and vanadium dioxide(VO_(2))and investigate its optical properties using the finite-difference time-domain(FDTD)technique.Using the phase transition feature of VO_(2),the design can realize active tuning of the plasmon induced transparency(PIT)effect at terahertz frequency,thereby converting from a single PIT to a double-PIT.When VO_(2) is in the insulating state,the structure is symmetric to obtain a single-band PIT effect.When VO_(2) is in the metallic state,the structure turns asymmetric to realize a dual-band PIT effect.This design provides a reference direction for the design of actively tunable metamaterials.Additionally,it is discovered that the transparent window's resonant frequency and the Fermi level in this structure have a somewhat linear relationship.In addition,the structure achieves superior refractive index sensitivity in the terahertz band,surpassing 1 THz/RIU.Consequently,the design exhibits encouraging potential for application in refractive index sensors and optical switches.
