Due to scale effects,micromechanical resonators offer an excellent platform for investigating the intrinsic mechanisms of nonlinear dynamical phenomena and their potential applications.This review focuses on mode-coup...Due to scale effects,micromechanical resonators offer an excellent platform for investigating the intrinsic mechanisms of nonlinear dynamical phenomena and their potential applications.This review focuses on mode-coupled micromechanical resonators,highlighting the latest advancements in four key areas:internal resonance,synchronization,frequency combs,and mode localization.The origin,development,and potential applications of each of these dynamic phenomena within mode-coupled micromechanical systems are investigated,with the goal of inspiring new ideas and directions for researchers in this field.展开更多
The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface...The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface with various physical systems.Equipped with gate electrodes,it has been demonstrated that these exceptional device properties can be electrically manipulated,leading to a variety of nanomechanical/acoustic applications.Here,we review the recent progress of graphene nanomechanical resonators with a focus on their electrical tunability.First,we provide an overview of diferent graphene nanomechanical resonators,including their device structures,fabrication methods,and measurement setups.Then,the key mechanical properties of these devices,for example,resonant frequencies,nonlinearities,dissipations,and mode coupling mechanisms,are discussed,with their behaviors upon electrical gating being highlighted.After that,various potential classical/quantum applications based on these graphene nanomechanical resonators are reviewed.Finally,we briefy discuss challenges and opportunities in this feld to ofer future prospects for the ongoing studies on graphene nanomechanical resonators.展开更多
To enhance the quality factor and sensitivity of refractive index sensors,a feedback waveguide slot grating micro-ring resonator was proposed.An air-hole grating structure was introduced based on the slot micro-ring,u...To enhance the quality factor and sensitivity of refractive index sensors,a feedback waveguide slot grating micro-ring resonator was proposed.An air-hole grating structure was introduced based on the slot micro-ring,utilizing the reflection of the grating to achieve the electromagnetic-like induced transparency effect at different wavelengths.The high slope characteristics of the EIT-like effect enabled a higher quality factor and sensitivity.The transmission principle of the structure was analyzed using the transmission matrix method,and the transmission spectrum and mode field distribution were simulated using the finite-difference time-domain(FDTD)method,and the device structure parameters were adjusted for optimization.Simulation results show that the proposed structure achieves an EIT-like effect with a quality factor of 59267.5.In the analysis of refractive index sensing characteristics,the structure exhibits a sensitivity of 408.57 nm/RIU and a detection limit of 6.23×10^(-5) RIU.Therefore,the proposed structure achieved both a high quality factor and refractive index sensitivity,demonstrating excellent sensing performance for applications in environmental monitoring,biomedical fields,and other areas with broad market potential.展开更多
Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of S...Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of Schottky noise detectors,the number of stored ions in the ring is determined by the peak area in the measured revolution frequency spectrum.Because of their intrinsic amplitude-frequency characteristic(AFC),Schottky detector systems exhibit varying sensitivities at different frequencies.Using low-energy electron-cooled stored ions,a new method is developed to calibrate the AFC curve of the Schottky detector system of the Experimental Cooler Storage Ring(CSRe)storage ring located in Lanzhou,China.Using the amplitude-calibrated frequency spectrum,a notable refinement was observed in the precision of both the peak position and peak area.As a result,the storage lifetimes of the electron-cooled fully ionized^(56)Fe^(26+)ions were determined with high precision at beam energies of 13.7 and 116.4 MeV/u,despite of frequency drifts during the experiment.When electron cooling was turned off,the effective vacuum condition experienced by the 116.4 MeV/u^(56)Fe^(26+)ions was determined using amplitude-calibrated spectra,revealing a value of 2×10^(−10)mbar,which is consistent with vacuum gauge readings along the CSRe ring.The method reported herein will be adapted for the next-generation storage ring of the HIAF facility under construction in Huizhou,China.It can also be adapted to other storage ring facilities worldwide to improve precision and enhance lifetime measurements using many ions in the ring.展开更多
Passive Kerr fiber-loop resonators driven by coherent lasers exhibit a variety of nonlinear states,including modulation instability(MI),localized dissipative structures(solitons),and chaos.Although these transitions h...Passive Kerr fiber-loop resonators driven by coherent lasers exhibit a variety of nonlinear states,including modulation instability(MI),localized dissipative structures(solitons),and chaos.Although these transitions have been predicted theoretically,experimental real-time observations are rare in coherently driven Kerr fiber-loop resonators.In this study,we observed real-time transitions between the predicted nonlinear states by sweeping detuning both positively and negatively.We discovered the transition path between nonlinear states depending on the direction of detuning,providing new insights into the nonlinear dynamics.Our findings directly validate theoretical predictions and offer potential implications for future nonlinear optical applications.展开更多
Enhancing the vibration resistance of micro-electro-mechanical systems(MEMS)resonators in complex environments is a critical issue that urgently needs to be addressed.This paper presents a chip-scale locally resonant ...Enhancing the vibration resistance of micro-electro-mechanical systems(MEMS)resonators in complex environments is a critical issue that urgently needs to be addressed.This paper presents a chip-scale locally resonant phononic crystal(LRPnC)plate based on a folded helical beam structure.Through finite element simulation and theoretical analysis,the bandgap characteristics and vibration suppression mechanisms of this structure were thoroughly investigated.The results show that the structure exhibits a complete bandgap in the frequency range of 9.867-14.605 kHz,and the bandgap can be effectively tuned by adjusting the structural parameters.Based on this,the influence of the number of unit cell layers on the vibration reduction performance was further studied,and a finite periodic LRPnC plate was constructed.Numerical studies have shown that the LRPnC plate can achieve more than-30 dB of vibration attenuation within the bandgap and effectively suppress y-direction coupling vibrations caused by x-direction propagating waves.In addition,its chip-scale size and planar structure design provide new ideas and methods for the engineering application of phononic crystal technology in the field of MEMS vibration isolation.展开更多
As an ultrathin wide-bandgap(WBG)material,CaNb_(2)O_(6)exhibits excellent optical and electrical properties.Particularly,its highly asymmetric crystal structure provides new opportunities for designing novel nanodevic...As an ultrathin wide-bandgap(WBG)material,CaNb_(2)O_(6)exhibits excellent optical and electrical properties.Particularly,its highly asymmetric crystal structure provides new opportunities for designing novel nanodevices with directional functionality.However,due to the significant challenges in applying conventional techniques to nanoscale samples,the in-plane anisotropy of CaNb_(2)O_(6)has still remained unexplored.Here,we leverage the resonant nanoelectromechanical systems(NEMS)platform to successfully quantify both the mechanical and thermal anisotropies in such an ultrathin WBG crystal.Specifically,by measuring the dynamic response in both spectral and spatial domains,we determine the anisotropic Young’s modulus of CaNb_(2)O_(6)as E_(Y(a))=70.42 GPa and EY(b)=116.2 GPa.By further expanding this technique to cryogenic temperatures,we unveil the anisotropy in thermal expansion coefficients as α_((a))=13.4 ppm·K^(-1),α(b)=2.9 ppm·K^(-1).Interestingly,through thermal strain engineering,we successfully modulate the mode sequence and achieve a crossing of(1×2)-(2×1)modes with perfect degeneracy.Our study provides guidelines for future CaNb_(2)O_(6)nanodevices with additional degrees of freedom and new device functions.展开更多
Two-dimensional phononic crystal(PnC)slabs have shown advantages in enhancing the quality factors Q of piezoelectric laterally vibrating resonators(LVRs)through topology optimization.However,the narrow geometries of m...Two-dimensional phononic crystal(PnC)slabs have shown advantages in enhancing the quality factors Q of piezoelectric laterally vibrating resonators(LVRs)through topology optimization.However,the narrow geometries of most topology-optimized silicon–air 2D PnC slabs face significant fabrication challenges owing to restricted etching precision,and the anisotropic nature of silicon is frequently overlooked.To address these issues,this study employs the finite element method with appropriate discretization numbers and the genetic algorithm to optimize the structures and geometries of 2D silicon–air PnC slabs.The optimized square-lattice PnC slabs,featuring a rounded-cross structure oriented along the`110e directions of silicon,achieve an impressive relative bandgap(RBG)width of 82.2%for in-plane modes.When further tilted by 15° from the (100) directions within the(001)plane,the optimal RBG width is expanded to 91.4%.We fabricate and characterize thin-film piezoelectric-on-silicon LVRs,with or without optimized 2D PnC slabs.The presence of PnC slabs around anchors increases the series and parallel quality factors Q_(s) and Q_(p) from 2240 to 7118 and from 2237 to 7501,respectively,with the PnC slabs oriented along the`110e directions of silicon.展开更多
Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optim...Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.展开更多
The topic of improving the mechanical stability of external cavity diode lasers(ECDLs)has recently attracted widespread attention and interest.The use of corner-cube-array(CCA)-based resonators provides a potential so...The topic of improving the mechanical stability of external cavity diode lasers(ECDLs)has recently attracted widespread attention and interest.The use of corner-cube-array(CCA)-based resonators provides a potential solution for this purpose,although continuous oscillation at super large incident angle remains challenging.In this work,we employ the CCA resonator to generate continuous oscillation within±20°angular misalignment of cavity mirror in experiment.On the basis of retroreflection theory,the retroreflectivity of a CCA is analyzed by using optical simulation software.Notably,the experiment verifies the advantage of using a CCA over a plane mirror in laser resonator,thereby providing a promising approach for ECDLs.The threshold characteristic curves measured at different incident angles in the experiment verify that the CCA possesses an obvious anti-angle misalignment performance.This research introduces an alternative solution of using CCA resonator instead of parallel plane cavity,thereby realizing an adjustment-free ECDL with enhanced mechanical stability.展开更多
Superconducting microwave resonators play a pivotal role in superconducting quantum circuits.The ability to finetune their resonant frequencies provides enhanced control and flexibility.Here,we introduce a frequency-t...Superconducting microwave resonators play a pivotal role in superconducting quantum circuits.The ability to finetune their resonant frequencies provides enhanced control and flexibility.Here,we introduce a frequency-tunable superconducting coplanar waveguide resonator.By applying electrical currents through specifically designed ground wires,we achieve the generation and control of a localized magnetic field on the central line of the resonator,enabling continuous tuning of its resonant frequency.We demonstrate a frequency tuning range of 54.85 MHz in a 6.21-GHz resonator.This integrated and tunable resonator holds great potential as a dynamically tunable filter and as a key component of communication buses and memory elements in superconducting quantum computing.展开更多
As for the ultra-precision grinding of the hemispherical fused silica resonator,due to the hard and brittle nature of fused silica,subsurface damage(SSD)is easily generated,which enormously influences the performance ...As for the ultra-precision grinding of the hemispherical fused silica resonator,due to the hard and brittle nature of fused silica,subsurface damage(SSD)is easily generated,which enormously influences the performance of such components.Hence,ultra-precision grinding experiments are carried out to investigate the surface/subsurface quality of the hemispherical resonator machined by the small ball-end fine diamond grinding wheel.The influence of grinding parameters on the surface roughness(SR)and SSD depth of fused silica samples is then analyzed.The experimental results indicate that the SR and SSD depth decreased with the increase of grinding speed and the decrease of feed rate and grinding depth.In addition,based on the material strain rate and the maximum undeformed chip thickness,the effect of grinding parameters on the subsurface damage mechanism of fused silica samples is analyzed.Furthermore,a multi-step ultra-precision grinding technique of the hemispherical resonator is proposed based on the interaction influence between grinding depth and feed rate.Finally,the hemispherical resonator is processed by the proposed grinding technique,and the SR is improved from 454.328 nm to 110.449 nm while the SSD depth is reduced by 94%from 40μm to 2.379μm.The multi-step grinding technique proposed in this paper can guide the fabrication of the hemispherical resonator.展开更多
This article analyzes the transmission line characteristics of plasmonic hybrid metal insulator metal(HMIM) wave-guide, circular ring resonator(CRR) based dual-band band-pass filters with two transmission poles in bot...This article analyzes the transmission line characteristics of plasmonic hybrid metal insulator metal(HMIM) wave-guide, circular ring resonator(CRR) based dual-band band-pass filters with two transmission poles in both pass-bands in the optical regime using coupled line feed. The transmission line characteristics of an HMIM waveguide, such as characteristic impedance(Z_(PV)), effective refractive index(n_(eff)) and propagation length(L_(spp)), have been obtained by using full wave simulation.展开更多
In this work,a new configuration of an all-optical nonlinear de-multiplexer gate based on two-dimensional(2D)photonic crystals(Ph C)is proposed.The gate is considered in the double-ring resonator shaped structure of s...In this work,a new configuration of an all-optical nonlinear de-multiplexer gate based on two-dimensional(2D)photonic crystals(Ph C)is proposed.The gate is considered in the double-ring resonator shaped structure of silicon rods.In order to have a more functional structure,some defect rods made of nonlinear materials were positioned in the structure.Considering the functionality of the structure,photonic band gap(PBG),field distribution and transmitted power spectra are investigated.Plane wave expansion and finite difference time domain(FDTD)methods are utilized for extracting the PBG and field distribution diagrams.The remarkable dimension,bit rate,maximum intensity and contrast ratio of 116.64μm2,3.125 Tbit/s,97%and 40.2 dB are obtained,respectively,which make the gate an appropriate candidate for utilization in optical integrated circuits.展开更多
To achieve high quality factor and high-sensitivity refractive index sensor,a slot micro-ring resonator(MRR)based on asymmetric Fabry-Perot(FP)cavity was proposed.The structure consisted of a pair of elliptical holes ...To achieve high quality factor and high-sensitivity refractive index sensor,a slot micro-ring resonator(MRR)based on asymmetric Fabry-Perot(FP)cavity was proposed.The structure consisted of a pair of elliptical holes to form an FP cavity and a microring resonator.The two different optical modes generated by the micro-ring resonator were destructively interfered to form a Fano line shape,which improved the system sensitivity while obtaining a higher quality factor and extinction ratio.The transmission principle of the structure was analyzed by the transfer matrix method.The transmission spectrum and mode field distribution of the proposed structure were simulated by the finite difference time domain(FDTD)method,and the key structural parameters affecting the Fano line shape in the device were optimized.The simulation results show that the quality factor of the device reached 22037.1,and the extinction ratio was 23.9 dB.By analyzing the refractive index sensing characteristics,the sensitivity of the structure was 354 nm·RIU−1,and the detection limit of the sensitivity was 2×10−4 RIU.Thus,the proposed compact asymmetric FP cavity slot micro-ring resonator has obvious advantages in sensing applications owing to its excellent performance.展开更多
Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap(D), critical...Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap(D), critical temperature(T_(c)),and quasiparticle density of states(QDOS) distribution, however, deviate from the classical BCS theory due to the disorder effects. The Usadel equation, which takes account of elastic scattering, non-elastic scattering, and electro–phonon coupling,can be applied to explain and describe these deviations. This paper presents numerical simulations of the disorder effects based on the Usadel equation to investigate their effects on the △, Tc, QDOS distribution, and complex conductivity of the NbTiN film. Furthermore, NbTiN superconducting resonators with coplanar waveguide(CPW) structures are fabricated and characterized at different temperatures to validate our numerical simulations. The pair-breaking parameter α and the critical temperature in the pure state T_(c)^(P) of our NbTiN film are determined from the experimental results and numerical simulations. This study has significant implications for the development of low-temperature detectors made of disordered superconducting materials.展开更多
Combining periodic layered structure with three-dimensional cylindrical local resonators,a hybrid metastructure with improved wave isolation ability was designed and investigated through theoretical and numerical appr...Combining periodic layered structure with three-dimensional cylindrical local resonators,a hybrid metastructure with improved wave isolation ability was designed and investigated through theoretical and numerical approaches.The metastructure is composed of periodic rubber layers and concrete layers embedded with three-dimensional resonators,which can be freely designed with multi local resonant frequencies to attenuate vibrations at required frequencies and widen the attenuation bandgap.The metastructure can also effectively attenuate seismic responses.Compared with layered rubber-based structures,the metastructure has more excellent wave attenuation effects with greater attenuation and wider bandgap.展开更多
Dielectric resonator magnetoelectric dipole(DRMED)arrays with enhanced isolation,reduced cross-polarization,and backward radiation are proposed for base station(BS)applications.The proposed antenna comprises an elevat...Dielectric resonator magnetoelectric dipole(DRMED)arrays with enhanced isolation,reduced cross-polarization,and backward radiation are proposed for base station(BS)applications.The proposed antenna comprises an elevated dielectric resonator antenna(DRA)on a small metal plate above a sizeable common ground plane.The DRA is designed in its T Eδ11 mode,acting like a magnetic dipole.The surface current excited by the differential probes flowing on the small ground plane is equivalent to an electric dipole.Since these two equivalent dipoles are orthogonal,they have the magnetoelectric dipole characteristics with reduced backward radiation.Meanwhile,the small ground planes can be treated as decoupling structures to provide a neutralization path to cancel the original coupling path.A linearly-polarized 4-element prototype array was verified experimentally in previous work.Here,a dual-polarized DRMED antenna is presented to construct a 2-element and 4×4 array for BS applications.To investigate its MIMO performance,sophisticated multi-cell scenario simulations are carried out.By using the proposed dualpolarized DRMED array,the cellular system capacityis improved by 118.6%compared to a conventional DRA array.This significant MIMO system improvement is mainly due to the reduced backward radiation and,therefore,reduced inter-cell interferences.Measurements align well with the simulations.展开更多
A novel high quality-factor(Q)micro-ring resonator(MRR)structure based on the Si_(3)N_(4) ridge-slot waveguide is proposed,and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb.We optim...A novel high quality-factor(Q)micro-ring resonator(MRR)structure based on the Si_(3)N_(4) ridge-slot waveguide is proposed,and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb.We optimized the structure of MRR by the finite element method and precise dispersion engineering,which finally obtained the suitable MRR geometry with negative dispersion characteristics at 1550 nm,having Q of 1.7×10^(7)and the absorption loss as low as 2.6×10^(-5) dB/cm.The simulation model of generating dual-comb is established as coupled Lugiato-Lefever equation(LLE),which takes the higher order dispersion,cross-phase modulation(XPM),multiphoton absorption,and external pumping into account.Solved by the split-step Fourier method(SSFM)and the fourth-order Runge-Kutta(RK4)method,the numerical results show that the generated dual-comb is periodically equally spaced distribution,but with slightly different intensities in the time domain.In the frequency domain,there are 64 comb teeth with intensities higher than-100 dBm with a bandwidth of 120 nm.Particularly,in the case of bicolor orthogonal polarization pumping,a smaller amount of detuning does not greatly affect the bandwidth of the dual-comb.展开更多
In order to explore the effect of unstable resonator stability on laser beam quality,the numerical simulation of midinfrared laser and visible laser was carried out in GLAD software.The simulation results showed that ...In order to explore the effect of unstable resonator stability on laser beam quality,the numerical simulation of midinfrared laser and visible laser was carried out in GLAD software.The simulation results showed that the existence of defocus aberration,tilt aberration and astigmatic aberration in the unstable resonator can cause the center of the far-field spot of the output annular beam to drift,the number of peripheral diffraction rings to increase,the beam quality to deteriorate,and the degree of effect is different.展开更多
基金supported by the National Key Research and Development Program of China(No.2022YFB3203600)the National Natural Science Foundation of China(Nos.12202355,12132013,and 12172323)the Zhejiang Provincial Natural Science Foundation of China(No.LZ22A020003)。
文摘Due to scale effects,micromechanical resonators offer an excellent platform for investigating the intrinsic mechanisms of nonlinear dynamical phenomena and their potential applications.This review focuses on mode-coupled micromechanical resonators,highlighting the latest advancements in four key areas:internal resonance,synchronization,frequency combs,and mode localization.The origin,development,and potential applications of each of these dynamic phenomena within mode-coupled micromechanical systems are investigated,with the goal of inspiring new ideas and directions for researchers in this field.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20240123)the National Key Research and Development Program of China(Grant No.2022YFA1405900)the National Natural Science Foundation of China(Grant Nos.12274397,12274401,and 12034018)。
文摘The excellent mechanical properties make graphene promising for realizing nanomechanical resonators with high resonant frequencies,large quality factors,strong nonlinearities,and the capability to efectively interface with various physical systems.Equipped with gate electrodes,it has been demonstrated that these exceptional device properties can be electrically manipulated,leading to a variety of nanomechanical/acoustic applications.Here,we review the recent progress of graphene nanomechanical resonators with a focus on their electrical tunability.First,we provide an overview of diferent graphene nanomechanical resonators,including their device structures,fabrication methods,and measurement setups.Then,the key mechanical properties of these devices,for example,resonant frequencies,nonlinearities,dissipations,and mode coupling mechanisms,are discussed,with their behaviors upon electrical gating being highlighted.After that,various potential classical/quantum applications based on these graphene nanomechanical resonators are reviewed.Finally,we briefy discuss challenges and opportunities in this feld to ofer future prospects for the ongoing studies on graphene nanomechanical resonators.
基金supported by Natural Science Foundation of Gansu Province(NO.21JR7RA289)。
文摘To enhance the quality factor and sensitivity of refractive index sensors,a feedback waveguide slot grating micro-ring resonator was proposed.An air-hole grating structure was introduced based on the slot micro-ring,utilizing the reflection of the grating to achieve the electromagnetic-like induced transparency effect at different wavelengths.The high slope characteristics of the EIT-like effect enabled a higher quality factor and sensitivity.The transmission principle of the structure was analyzed using the transmission matrix method,and the transmission spectrum and mode field distribution were simulated using the finite-difference time-domain(FDTD)method,and the device structure parameters were adjusted for optimization.Simulation results show that the proposed structure achieves an EIT-like effect with a quality factor of 59267.5.In the analysis of refractive index sensing characteristics,the structure exhibits a sensitivity of 408.57 nm/RIU and a detection limit of 6.23×10^(-5) RIU.Therefore,the proposed structure achieved both a high quality factor and refractive index sensitivity,demonstrating excellent sensing performance for applications in environmental monitoring,biomedical fields,and other areas with broad market potential.
基金supported by the National Key R&D Program of China (No. 2023YFA1606401 and 2018YFA0404401)the Young Scholar of Regional Development,CAS ([2023] 15)+1 种基金Chinese Academy of Sciences Stable Support for Young Teams in Basic Research (No. YSBR-002)Special Fund for Strategic Pilot Technology of Chinese Academy of Sciences (No. XDB34000000)
文摘Schottky mass spectrometry utilizing heavy-ion storage rings is a powerful technique for the precise mass and decay half-life measurements of highly charged ions.Owing to the nondestructive ion detection features of Schottky noise detectors,the number of stored ions in the ring is determined by the peak area in the measured revolution frequency spectrum.Because of their intrinsic amplitude-frequency characteristic(AFC),Schottky detector systems exhibit varying sensitivities at different frequencies.Using low-energy electron-cooled stored ions,a new method is developed to calibrate the AFC curve of the Schottky detector system of the Experimental Cooler Storage Ring(CSRe)storage ring located in Lanzhou,China.Using the amplitude-calibrated frequency spectrum,a notable refinement was observed in the precision of both the peak position and peak area.As a result,the storage lifetimes of the electron-cooled fully ionized^(56)Fe^(26+)ions were determined with high precision at beam energies of 13.7 and 116.4 MeV/u,despite of frequency drifts during the experiment.When electron cooling was turned off,the effective vacuum condition experienced by the 116.4 MeV/u^(56)Fe^(26+)ions was determined using amplitude-calibrated spectra,revealing a value of 2×10^(−10)mbar,which is consistent with vacuum gauge readings along the CSRe ring.The method reported herein will be adapted for the next-generation storage ring of the HIAF facility under construction in Huizhou,China.It can also be adapted to other storage ring facilities worldwide to improve precision and enhance lifetime measurements using many ions in the ring.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12475006 and 12004309)the Shaanxi Fundamental Science Research Project for Mathematics and Physics(Grant No.22JSQ036)。
文摘Passive Kerr fiber-loop resonators driven by coherent lasers exhibit a variety of nonlinear states,including modulation instability(MI),localized dissipative structures(solitons),and chaos.Although these transitions have been predicted theoretically,experimental real-time observations are rare in coherently driven Kerr fiber-loop resonators.In this study,we observed real-time transitions between the predicted nonlinear states by sweeping detuning both positively and negatively.We discovered the transition path between nonlinear states depending on the direction of detuning,providing new insights into the nonlinear dynamics.Our findings directly validate theoretical predictions and offer potential implications for future nonlinear optical applications.
基金supported by National Natural Science Foundation of China(No.62271262).
文摘Enhancing the vibration resistance of micro-electro-mechanical systems(MEMS)resonators in complex environments is a critical issue that urgently needs to be addressed.This paper presents a chip-scale locally resonant phononic crystal(LRPnC)plate based on a folded helical beam structure.Through finite element simulation and theoretical analysis,the bandgap characteristics and vibration suppression mechanisms of this structure were thoroughly investigated.The results show that the structure exhibits a complete bandgap in the frequency range of 9.867-14.605 kHz,and the bandgap can be effectively tuned by adjusting the structural parameters.Based on this,the influence of the number of unit cell layers on the vibration reduction performance was further studied,and a finite periodic LRPnC plate was constructed.Numerical studies have shown that the LRPnC plate can achieve more than-30 dB of vibration attenuation within the bandgap and effectively suppress y-direction coupling vibrations caused by x-direction propagating waves.In addition,its chip-scale size and planar structure design provide new ideas and methods for the engineering application of phononic crystal technology in the field of MEMS vibration isolation.
基金supported by the National Key R&D Program of China(2022YFB3203600)the National Natural Science Foundation of China(Grant Nos.T2325007,62450003,62401104,62404029,U21A20459,62250073,61774029,and U23A20570)+1 种基金the China Postdoctoral Science Foundation(Grant Nos.GZB20230107 and GZB20240109)the Natural Science Foundation of Sichuan Province(Grant Nos.2024NSFSC1430 and 2024NSFSC1408).
文摘As an ultrathin wide-bandgap(WBG)material,CaNb_(2)O_(6)exhibits excellent optical and electrical properties.Particularly,its highly asymmetric crystal structure provides new opportunities for designing novel nanodevices with directional functionality.However,due to the significant challenges in applying conventional techniques to nanoscale samples,the in-plane anisotropy of CaNb_(2)O_(6)has still remained unexplored.Here,we leverage the resonant nanoelectromechanical systems(NEMS)platform to successfully quantify both the mechanical and thermal anisotropies in such an ultrathin WBG crystal.Specifically,by measuring the dynamic response in both spectral and spatial domains,we determine the anisotropic Young’s modulus of CaNb_(2)O_(6)as E_(Y(a))=70.42 GPa and EY(b)=116.2 GPa.By further expanding this technique to cryogenic temperatures,we unveil the anisotropy in thermal expansion coefficients as α_((a))=13.4 ppm·K^(-1),α(b)=2.9 ppm·K^(-1).Interestingly,through thermal strain engineering,we successfully modulate the mode sequence and achieve a crossing of(1×2)-(2×1)modes with perfect degeneracy.Our study provides guidelines for future CaNb_(2)O_(6)nanodevices with additional degrees of freedom and new device functions.
基金supported by the National Natural Science Foundation of China(Grant No.52175552)the National Key RD Program of China(Grant Nos.2022YFB3205400 and 2022YFB3204300).
文摘Two-dimensional phononic crystal(PnC)slabs have shown advantages in enhancing the quality factors Q of piezoelectric laterally vibrating resonators(LVRs)through topology optimization.However,the narrow geometries of most topology-optimized silicon–air 2D PnC slabs face significant fabrication challenges owing to restricted etching precision,and the anisotropic nature of silicon is frequently overlooked.To address these issues,this study employs the finite element method with appropriate discretization numbers and the genetic algorithm to optimize the structures and geometries of 2D silicon–air PnC slabs.The optimized square-lattice PnC slabs,featuring a rounded-cross structure oriented along the`110e directions of silicon,achieve an impressive relative bandgap(RBG)width of 82.2%for in-plane modes.When further tilted by 15° from the (100) directions within the(001)plane,the optimal RBG width is expanded to 91.4%.We fabricate and characterize thin-film piezoelectric-on-silicon LVRs,with or without optimized 2D PnC slabs.The presence of PnC slabs around anchors increases the series and parallel quality factors Q_(s) and Q_(p) from 2240 to 7118 and from 2237 to 7501,respectively,with the PnC slabs oriented along the`110e directions of silicon.
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301500)the National Natural Science Foundation of China(Grant No.62105366)。
文摘Microring resonators(MRRs)are extensively utilized in photonic chips for generating quantum light sources and enabling high-efficiency nonlinear frequency conversion.However,conventional microrings are typically optimized for a single specific function,limiting their versatility in multifunctional applications.In this work,we propose a reconfigurable microring resonator architecture designed to accommodate diverse application requirements.By integrating a cascaded Mach–Zehnder interferometer(MZI)as the microring coupler,the design enables independent control of the quality factors for pump,signal and idler photons through two tunable phase shifters.This capability allows for dynamic tuning and optimization of critical performance parameters,including photon-pair generation rate(PGR),spectral purity and single photon heralding efficiency(HE).The proposed structure is implemented on a silicon photonic chip,and experimental results exhibit a wide range of tunability for these parameters,with excellent agreement with theoretical predictions.This flexible and multi-functional design offers a promising pathway for high-performance,highly integrated on-chip quantum information processing systems.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20240613)Jiangsu Province’s“Innovation and Entrepreneurship Doctor”Program(Grant No.JSSCBS20230088)+4 种基金Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY224123)Natural Science Research Start-up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications(Grant No.NY222112)Beijing Nova Program(Grant No.20240484696)Wenzhou Major Science and Technology Innovation Key Project(Grant No.ZG2020046)INNOVATION Program for Quantum Science and Technology(Grant No.2021ZD0303200)。
文摘The topic of improving the mechanical stability of external cavity diode lasers(ECDLs)has recently attracted widespread attention and interest.The use of corner-cube-array(CCA)-based resonators provides a potential solution for this purpose,although continuous oscillation at super large incident angle remains challenging.In this work,we employ the CCA resonator to generate continuous oscillation within±20°angular misalignment of cavity mirror in experiment.On the basis of retroreflection theory,the retroreflectivity of a CCA is analyzed by using optical simulation software.Notably,the experiment verifies the advantage of using a CCA over a plane mirror in laser resonator,thereby providing a promising approach for ECDLs.The threshold characteristic curves measured at different incident angles in the experiment verify that the CCA possesses an obvious anti-angle misalignment performance.This research introduces an alternative solution of using CCA resonator instead of parallel plane cavity,thereby realizing an adjustment-free ECDL with enhanced mechanical stability.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2021YFA0718802 and 2018YFA0209002)the National Natural Science Foundation of China(Grant Nos.62274086,62288101,61971464,62101243,and 11961141002)+3 种基金the Excellent Young Scholar Program of Jiangsu Province,China(Grant Nos.BK20200008 and BK20200060)the Outstanding Postdoctoral Program of Jiangsu Province,Chinathe Fundamental Research Funds for the Central Universitiesthe Fund from Jiangsu Key Laboratory of Advanced Techniques for Manipulating Electromagnetic Waves。
文摘Superconducting microwave resonators play a pivotal role in superconducting quantum circuits.The ability to finetune their resonant frequencies provides enhanced control and flexibility.Here,we introduce a frequency-tunable superconducting coplanar waveguide resonator.By applying electrical currents through specifically designed ground wires,we achieve the generation and control of a localized magnetic field on the central line of the resonator,enabling continuous tuning of its resonant frequency.We demonstrate a frequency tuning range of 54.85 MHz in a 6.21-GHz resonator.This integrated and tunable resonator holds great potential as a dynamically tunable filter and as a key component of communication buses and memory elements in superconducting quantum computing.
基金This work was supported by the National Key Research and Development Program of China(No.2022YFB3403600)the National Natural Science Foundation of China(No.52293403)Self-Planned Task of State Key Laboratory of Robotics and System(HIT)(No.SKLRS202204C).
文摘As for the ultra-precision grinding of the hemispherical fused silica resonator,due to the hard and brittle nature of fused silica,subsurface damage(SSD)is easily generated,which enormously influences the performance of such components.Hence,ultra-precision grinding experiments are carried out to investigate the surface/subsurface quality of the hemispherical resonator machined by the small ball-end fine diamond grinding wheel.The influence of grinding parameters on the surface roughness(SR)and SSD depth of fused silica samples is then analyzed.The experimental results indicate that the SR and SSD depth decreased with the increase of grinding speed and the decrease of feed rate and grinding depth.In addition,based on the material strain rate and the maximum undeformed chip thickness,the effect of grinding parameters on the subsurface damage mechanism of fused silica samples is analyzed.Furthermore,a multi-step ultra-precision grinding technique of the hemispherical resonator is proposed based on the interaction influence between grinding depth and feed rate.Finally,the hemispherical resonator is processed by the proposed grinding technique,and the SR is improved from 454.328 nm to 110.449 nm while the SSD depth is reduced by 94%from 40μm to 2.379μm.The multi-step grinding technique proposed in this paper can guide the fabrication of the hemispherical resonator.
文摘This article analyzes the transmission line characteristics of plasmonic hybrid metal insulator metal(HMIM) wave-guide, circular ring resonator(CRR) based dual-band band-pass filters with two transmission poles in both pass-bands in the optical regime using coupled line feed. The transmission line characteristics of an HMIM waveguide, such as characteristic impedance(Z_(PV)), effective refractive index(n_(eff)) and propagation length(L_(spp)), have been obtained by using full wave simulation.
文摘In this work,a new configuration of an all-optical nonlinear de-multiplexer gate based on two-dimensional(2D)photonic crystals(Ph C)is proposed.The gate is considered in the double-ring resonator shaped structure of silicon rods.In order to have a more functional structure,some defect rods made of nonlinear materials were positioned in the structure.Considering the functionality of the structure,photonic band gap(PBG),field distribution and transmitted power spectra are investigated.Plane wave expansion and finite difference time domain(FDTD)methods are utilized for extracting the PBG and field distribution diagrams.The remarkable dimension,bit rate,maximum intensity and contrast ratio of 116.64μm2,3.125 Tbit/s,97%and 40.2 dB are obtained,respectively,which make the gate an appropriate candidate for utilization in optical integrated circuits.
基金supported by Natural Science Foundation of Gansu Province(No.22JR5RA320).
文摘To achieve high quality factor and high-sensitivity refractive index sensor,a slot micro-ring resonator(MRR)based on asymmetric Fabry-Perot(FP)cavity was proposed.The structure consisted of a pair of elliptical holes to form an FP cavity and a microring resonator.The two different optical modes generated by the micro-ring resonator were destructively interfered to form a Fano line shape,which improved the system sensitivity while obtaining a higher quality factor and extinction ratio.The transmission principle of the structure was analyzed by the transfer matrix method.The transmission spectrum and mode field distribution of the proposed structure were simulated by the finite difference time domain(FDTD)method,and the key structural parameters affecting the Fano line shape in the device were optimized.The simulation results show that the quality factor of the device reached 22037.1,and the extinction ratio was 23.9 dB.By analyzing the refractive index sensing characteristics,the sensitivity of the structure was 354 nm·RIU−1,and the detection limit of the sensitivity was 2×10−4 RIU.Thus,the proposed compact asymmetric FP cavity slot micro-ring resonator has obvious advantages in sensing applications owing to its excellent performance.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11925304 and 12020101002)the Chinese Academy of Sciences Program(Grant No.GJJSTD20210002).
文摘Disordered superconducting materials like NbTiN possess a high kinetic inductance fraction and an adjustable critical temperature, making them a good choice for low-temperature detectors. Their energy gap(D), critical temperature(T_(c)),and quasiparticle density of states(QDOS) distribution, however, deviate from the classical BCS theory due to the disorder effects. The Usadel equation, which takes account of elastic scattering, non-elastic scattering, and electro–phonon coupling,can be applied to explain and describe these deviations. This paper presents numerical simulations of the disorder effects based on the Usadel equation to investigate their effects on the △, Tc, QDOS distribution, and complex conductivity of the NbTiN film. Furthermore, NbTiN superconducting resonators with coplanar waveguide(CPW) structures are fabricated and characterized at different temperatures to validate our numerical simulations. The pair-breaking parameter α and the critical temperature in the pure state T_(c)^(P) of our NbTiN film are determined from the experimental results and numerical simulations. This study has significant implications for the development of low-temperature detectors made of disordered superconducting materials.
基金Supports from National Natural Science Foundation of China(Grant Nos.U20A20286 and 11972184)the Systematic Project of Guangxi Key Laboratory of Disaster Prevention and Engineering Safety(Grant No.2021ZDK006)+1 种基金Natural Science Foundation of Jiangsu Province of China(Grant No.BK20201286)Science and Technology Project of Jiangsu Province of China(Grant No.BE2020716)are gratefully acknowledged.
文摘Combining periodic layered structure with three-dimensional cylindrical local resonators,a hybrid metastructure with improved wave isolation ability was designed and investigated through theoretical and numerical approaches.The metastructure is composed of periodic rubber layers and concrete layers embedded with three-dimensional resonators,which can be freely designed with multi local resonant frequencies to attenuate vibrations at required frequencies and widen the attenuation bandgap.The metastructure can also effectively attenuate seismic responses.Compared with layered rubber-based structures,the metastructure has more excellent wave attenuation effects with greater attenuation and wider bandgap.
基金supported by the National Key Research and Development Program of China under Grant 2020YFA0709800.
文摘Dielectric resonator magnetoelectric dipole(DRMED)arrays with enhanced isolation,reduced cross-polarization,and backward radiation are proposed for base station(BS)applications.The proposed antenna comprises an elevated dielectric resonator antenna(DRA)on a small metal plate above a sizeable common ground plane.The DRA is designed in its T Eδ11 mode,acting like a magnetic dipole.The surface current excited by the differential probes flowing on the small ground plane is equivalent to an electric dipole.Since these two equivalent dipoles are orthogonal,they have the magnetoelectric dipole characteristics with reduced backward radiation.Meanwhile,the small ground planes can be treated as decoupling structures to provide a neutralization path to cancel the original coupling path.A linearly-polarized 4-element prototype array was verified experimentally in previous work.Here,a dual-polarized DRMED antenna is presented to construct a 2-element and 4×4 array for BS applications.To investigate its MIMO performance,sophisticated multi-cell scenario simulations are carried out.By using the proposed dualpolarized DRMED array,the cellular system capacityis improved by 118.6%compared to a conventional DRA array.This significant MIMO system improvement is mainly due to the reduced backward radiation and,therefore,reduced inter-cell interferences.Measurements align well with the simulations.
基金supported by the National Natural Science Foundation of China(No.61505160)the Innovation Capability Support Program of Shaanxi (No.2018KJXX-042)+2 种基金the Natural Science Basic Research Program of Shaanxi(No.2019JM-084)the State Key Laboratory of Transient Optics and Photonics(No.SKLST202108)the Postgraduate Innovation and Practice Ability Development Fund of Xi’an Shiyou University(No.YCS22213174)。
文摘A novel high quality-factor(Q)micro-ring resonator(MRR)structure based on the Si_(3)N_(4) ridge-slot waveguide is proposed,and the MRR is pumped by orthogonally polarized bicolor pumping to generate dual-comb.We optimized the structure of MRR by the finite element method and precise dispersion engineering,which finally obtained the suitable MRR geometry with negative dispersion characteristics at 1550 nm,having Q of 1.7×10^(7)and the absorption loss as low as 2.6×10^(-5) dB/cm.The simulation model of generating dual-comb is established as coupled Lugiato-Lefever equation(LLE),which takes the higher order dispersion,cross-phase modulation(XPM),multiphoton absorption,and external pumping into account.Solved by the split-step Fourier method(SSFM)and the fourth-order Runge-Kutta(RK4)method,the numerical results show that the generated dual-comb is periodically equally spaced distribution,but with slightly different intensities in the time domain.In the frequency domain,there are 64 comb teeth with intensities higher than-100 dBm with a bandwidth of 120 nm.Particularly,in the case of bicolor orthogonal polarization pumping,a smaller amount of detuning does not greatly affect the bandwidth of the dual-comb.
基金supported by the Hunan Department of Education Funded Research Project(No.23A0581)the Hunan Provincial Social Science Achievement Committee Project(No.XSP24YBZ198)the Teaching Reform Project of Hunan University of Science and Engineering(No.[2022]45-XKYJ2022014)。
文摘In order to explore the effect of unstable resonator stability on laser beam quality,the numerical simulation of midinfrared laser and visible laser was carried out in GLAD software.The simulation results showed that the existence of defocus aberration,tilt aberration and astigmatic aberration in the unstable resonator can cause the center of the far-field spot of the output annular beam to drift,the number of peripheral diffraction rings to increase,the beam quality to deteriorate,and the degree of effect is different.
