A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep aval...A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep avalanche multiplication region for near-infrared(NIR)sensitivity enhancement.By optimizing the device size and electric field of the guard ring,the fill factor(FF)is significantly improved,further increasing photon detection efficiency(PDE).To solve the dark noise caused by the increasing active diameter,a field polysilicon gate structure connected to the p+anode was investigated,effectively suppressing dark count noise by 76.6%.It is experimentally shown that when the active diameter increases from 5 to 10μm,the FF is significantly improved from 20.7%to 39.1%,and thus the peak PDE also rises from 13.3%to 25.8%.At an excess bias voltage of 5 V,a NIR photon detection probability(PDP)of 6.8%at 905 nm,a dark count rate(DCR)of 2.12 cps/μm^(2),an afterpulsing probability(AP)of 1.2%,and a timing jitter of 216 ps are achieved,demonstrating excellent single photon detection performance.展开更多
Pairs of entangled vortex photons can promise new prospects of application in quantum computing and cryptography.We investigate the possibility of generating such states via two-level atom emission induced by a single...Pairs of entangled vortex photons can promise new prospects of application in quantum computing and cryptography.We investigate the possibility of generating such states via two-level atom emission induced by a single photon wave packet with a definite total angular momentum(TAM).The entangled pair produced in this process possesses well-defined mean TAM with the TAM variation being much smaller than h.On top of that,the variation exponentially decreases with the increase in TAM of the incident photon.Our model allows one to track the time evolution of the state of the entangled pair.An experimentally feasible scenario is assumed,in which the incident photon interacts with a spatially confined atomic target.We conclude that induced emission can be used as a source of entangled vortex photons with applications in atomic physics experiments,quantum optics,and quantum information sciences.展开更多
An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mod...An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mode area and nonlinear coefficient were investigated by using finite element method(FEM),the evolu-tion of optical pulses propagating along the fiber was simulated,and the supercontinuum and the coherence were analyzed and evaluated under different pumping conditions.The results show that a supercontinuum spectrum with a spectral width of 4.852μm can be obtained in the proposed fiber with d_(1)/Λof 0.125,d_(2)/Λof 0.583 and the zero-dispersion wavelength of 3.228μm by pumping with a Gaussian pulse with a peak power of 800 W and a full width at half maximum(FWHM)of 20 fs at wavelength of 3.3μm.When the fiber is pumped by the pulse with the peak power of 2000 W,the FWHM of 80 fs at the wavelength of 4.0μm in the in the anomalous dispersion region,the modulation instability is obviously suppressed,and the high-coher-ence supercontinuum spectrum spanning from 1.1μm to 8.99μm is observed.A part of the pulse energy is transferred to the anomalous dispersion region when pumped at the wavelength of 2.8μm in the normal dis-persion region and a broadband high-coherence supercontinuum spectrum extending from 0.8μm to 9.8μm is generated in the 10 mm proposed fiber.This paper introduces elliptical air holes in the Al_(0.24)Ga_(0.76)As photonic crystal fiber,which enhances flexibility for tailoring the performance of supercontinuum,ultimately achieving the broadest supercontinuum spectrum with the shortest fiber length to date.展开更多
Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wave...Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wavelength division multiplexing silicon photonics receiver chip composed of an arrayed waveguide grating and Ge-on-Si photodetectors. Integrated inductors are introduced to enhance the high-speed performance of photodetectors, enabling data rates up to 112 Gbps with high responsivity and low dark current. The operating wavelength range of the arrayed wavelength grating is adjusted according to the response of the Ge-on-Si photodetector. The optical insertion loss, cross talk and central wavelength of the array waveguide grating are 2.1 to 3.7 d B,-12 to-15 d B, and 1538 nm, respectively. The proposed receiver chip offers a solution to meet the challenges of modern data transmission requirements.展开更多
A symmetrical one-dimensional(1D)photonic crystal structure with a Dirac-emimetal-defected layer is proposed.The material properties of the Dirac semimetal are governed by three key parameters:Fermi level,Fermi veloci...A symmetrical one-dimensional(1D)photonic crystal structure with a Dirac-emimetal-defected layer is proposed.The material properties of the Dirac semimetal are governed by three key parameters:Fermi level,Fermi velocity,and degeneracy factor.Simulation results demonstrate that the proposed structure generates multiple photonic bandgaps within the THz frequency range.In the low-THz region,pronounced resonant transmission peaks emerge,enabling near-perfect filtering performance.The positions of these defect modes can be dynamically tuned by adjusting the Fermi level and degeneracy factor.In mid-and high-THz frequency bands,the Dirac semimetal begins to exhibit metallic behavior,leading to attenuation of the transmission peaks and the appearance of absorption.The elevation of the Fermi level delays the critical threshold for the transition from the dielectric state to the metallic state,while an increase in Fermi velocity suppresses metallic behavior.Therefore,enhancing both the Fermi level and Fermi velocity contributes to strengthening the defect peak intensity.Conversely,increasing the degeneracy factor strengthens the metallic characteristics,thereby disrupting the high-frequency photonic bandgap.Notably,the defect layer thickness and incident angle exert significant influence on the transmission behavior:a larger incident angle causes the defect peak to shift toward higher frequencies and reduces its intensity,whereas a thicker defect layer shifts the defect peak toward lower frequencies.The modulation effects of both parameters become more pronounced as frequency increases.Compared with conventional photonic crystals,our work can provide a tunable structure over transmission properties,offering novel strategies for designing tunable filters and optical sensors.展开更多
The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that ...The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that the injected beam has a short bunch length and low emittance,and the preferred injector should offer high stability and low cost.Therefore,an injector based on a booster synchrotron was developed.The proposed injector includes a 250 MeV linac,a booster synchrotron that ramps the beam energy to 3.5 GeV,and two beam transport lines to ensure efficient beam delivery and beam quality preservation.The linac utilizes a thermionic high-voltage DC gun for reliable operation and features a bunching system with an advanced focusing system to preserve the emittance.To meet the injection requirements of the SAPS,a comprehensive design for the booster has been conducted.The booster synchrotron employs a threefold lattice structure,incorporating modified theoretical minimum emittance cells with a small momentum compaction factor and a high voltage to achieve an emittance of 3.98 nm rad and a bunch length of 4.8 mm.The injector has the potential to deliver a high charge,reducing the injection period of the storage ring to less than 1 min.Simulations demonstrated the expected performance,with a transmission efficiency of 90%,confirming its capability to meet the injection requirement of the SAPS storage ring.This design offers a stable and efficient solution for the SAPS.展开更多
Methods allowing passive daytime radiative cooling(PDRC)to be carried out in an energy-efficient and scalable way are potentially important for various disciplines.Here,we report a sustainable strategy for scalable-de...Methods allowing passive daytime radiative cooling(PDRC)to be carried out in an energy-efficient and scalable way are potentially important for various disciplines.Here,we report a sustainable strategy for scalable-designed and color-regulating PDRC coating based on high-crystallinity photonic metamaterial(crystallinity:71.5%;enhanced assembly efficiency:72%),that is derived from the as-prepared 55 wt%solid content poly(methyl methacrylate-butyl acrylate-methacrylic acid)P(MMA-BA-MAA)monodispersed latexes(approaching theoretical limit:59 wt%).Robust meter-scale PDRC coatings are constructed by various industrial modes onto diverse surfaces,addressing bottlenecks like dull appearance,high cost,low efficiency,and hard construction.Notably,the solar reflectance,long-wave infrared emittance,and calculated theoretical cooling power of the designed PDRC coating,respectively,reach~0.94,~0.97,and~95.5 W m^(-2)under solar radiation,which can achieve an average 5.3℃sub-ambient daytime temperature drop in the summer in Nanjing.The cooling performance,scale preparation,and cost-effectiveness of the PDRC coating have extended into leading position compared with those of state-of-the-art designs.This work provides promising route to reduce carbon emissions and energy consumption for global sustainability.展开更多
The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon ...The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.展开更多
In this paper,a terahertz slotted waveguide array antenna is designed based on photonic crystal,which can realize efficient radiation of terahertz waves.The electromagnetic wave is fed from the rectangular waveguide a...In this paper,a terahertz slotted waveguide array antenna is designed based on photonic crystal,which can realize efficient radiation of terahertz waves.The electromagnetic wave is fed from the rectangular waveguide at the bottom of the antenna,coupled to photonic crystal waveguide through photonic crystal cavity,and radiated outward through slots at the top layer of antenna.The simulation results show that the antenna achieves a peak gain of 13.45 dBi at 360 GHz,a half-power beam width of 10.9°,and a side lobe level of−13.9 dB.The antenna based on photonic crystal has the advantages of low profile,low loss,and high radiation efficiency,which can be applied to terahertz wireless communication systems.展开更多
A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of co...A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of concept.For this purpose,we have investigated the programmable photonic integrated circuit comprising 14 tunable balanced Mach–Zehnder interferometers designed into a square mesh architecture and fabricated using CMOS-compatible silicon photonic technology.展开更多
The bidirectional convergence of artificial intelligence and nanophotonics drives photonic technologies toward unprecedented levels of intelligence and efficiency,fundamentally reshaping their design paradigms and app...The bidirectional convergence of artificial intelligence and nanophotonics drives photonic technologies toward unprecedented levels of intelligence and efficiency,fundamentally reshaping their design paradigms and application boundaries.With its powerful data-driven and nonlinear optimization capabilities,artificial intelligence has become a powerful tool for optical design,enabling the inverse design of nanophotonics devices while accelerating the forward computation of electromagnetic responses.Conversely,nanophotonics provides a wave-based computational platform,giving rise to novel optical neural networks that achieve high-speed parallel computing and efficient information processing.This paper reviews the latest progress in the bidirectional field of artificial intelligence and nanophotonics,analyzes the basic principles of various applications from a universal perspective,comprehensively evaluates the advantages and limitations of different research methods,and makes a forwardlooking outlook on the bidirectional integration of artificial intelligence and nanophotonics,focusing on analyzing future development trends,potential applications,and challenges.The deep integration of artificial intelligence and nanophotonics is ushering in a new era for photonic technologies,offering unparalleled opportunities for fundamental research and industrial applications.展开更多
Artificial intelligence(AI)has taken breathtaking leaps forward in recent years,evolving into a strategic technology for pioneering the future.The growing demand for computing power—especially in demanding inference ...Artificial intelligence(AI)has taken breathtaking leaps forward in recent years,evolving into a strategic technology for pioneering the future.The growing demand for computing power—especially in demanding inference tasks,exemplified by generative AI models such as ChatGPT—poses challenges for conventional electronic computing systems.Advances in photonics technology have ignited interest in investigating photonic computing as a promising AI computing modality.Through the profound fusion of AI and photonics technologies,intelligent photonics is developing as an emerging interdisciplinary field with significant potential to revolutionize practical applications.Deep learning,as a subset of AI,presents efficient avenues for optimizing photonic design,developing intelligent optical systems,and performing optical data processing and analysis.Employing AI in photonics can empower applications such as smartphone cameras,biomedical microscopy,and virtual and augmented reality displays.Conversely,leveraging photonics-based devices and systems for the physical implementation of neural networks enables high speed and low energy consumption.Applying photonics technology in AI computing is expected to have a transformative impact on diverse fields,including optical communications,automatic driving,and astronomical observation.Here,recent advances in intelligent photonics are presented from the perspective of the synergy between deep learning and metaphotonics,holography,and quantum photonics.This review also spotlights relevant applications and offers insights into challenges and prospects.展开更多
Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge ...Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.展开更多
We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momen...We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.展开更多
The combining microelectronic devices and associated technologies onto a single silicon chip poses a substantial challenge.However,in recent years,the area of silicon photonics has experienced remarkable advancements ...The combining microelectronic devices and associated technologies onto a single silicon chip poses a substantial challenge.However,in recent years,the area of silicon photonics has experienced remarkable advancements and notable leaps in performance.The performance of silicon on insulator(SOI)based photonic devices,such as fast silicon optical modulators,photonic transceivers,optical filters,etc.,have been discussed.This would be a step forward in creating standalone silicon photonic devices,strengthening the possibility of single on-chip nanophotonic integrated circuits.Suppose an integrated silicon photonic chip is designed and fabricated.In that case,it might drastically modify these combined photonic component costs,power consumption,and size,bringing substantial,perhaps revolutionary,changes to the next-generation communications sector.Yet,the monolithic integration of photonic and electrical circuitry is a significant technological difficulty.A complicated set of factors must be carefully considered to determine which application will have the best chance of success employing silicon-based integrated product solutions.The processing limitations connected to the current process flow,the process generation(sometimes referred to as lithography node generation),and packaging requirements are a few of these factors to consider.This review highlights recent developments in integrated silicon photonic devices and their proven applications,including but not limited to photonic waveguides,photonic amplifiers and filters,onchip photonic transceivers,and the state-of-the-art of silicon photonic in multidimensional quantum systems.The investigated devices aim to expedite the transfer of silicon photonics from academia to industry by opening the next phase in on-chip silicon photonics and enabling the application of silicon photonic-based devices in various optical systems.展开更多
The investigation of topological transitions has opened up unprecedented avenues for scientific exploration in photonic metamaterials.However,previous studies mainly focused on exploring different types of three-dimen...The investigation of topological transitions has opened up unprecedented avenues for scientific exploration in photonic metamaterials.However,previous studies mainly focused on exploring different types of three-dimensional(3D)equifrequency surfaces and their topological transition processes in magnetic topological systems.In this work,we study the multiple photonic topological transitions and dual-frequency photonic Weyl points in the topological chiral metamaterials.Through effective medium theory and topological band theory,we systematically characterize and draw comprehensive topological phase diagrams associated with diverse 3D equifrequency surface configurations in nonmagnetic photonic systems.We further demonstrate that the resonance frequencyω0 and dual-frequency Weyl points are the critical points of these topological transitions.Notably,when the vacuum state is in contact with the phases I or III chiral metamaterials,the high-local and frequency chirality-dependent topological Fermi arc surface states arise.We reveal that the parameterωcan be used as a degree of freedom to regulate the bandwidth of such topological surface states.Moreover,different types of multichannel and directional topological photonic routings are achieved using the chirality-dependent Fermi arc surface states.We theoretically show that the physical mechanism of achieving these multichannel topological photonic routings is caused by the different interface properties.We could offer promising perspectives on 3D topological semimetal systems and provide more adaptability for multichannel devices in the nonmagnetic continuous media.展开更多
Silicon nitride photonics has emerged as a promising integrated optical platform due to its broad transparency window,low optical loss,and mature fabrication technology.However,the inherent centrosymmetric crystal str...Silicon nitride photonics has emerged as a promising integrated optical platform due to its broad transparency window,low optical loss,and mature fabrication technology.However,the inherent centrosymmetric crystal structure of silicon nitride fundamentally restricts its applications in second-order nonlinear optical processes.Monolayer transition metal dichalcogenides,particularly tungsten disulfide(WS_(2)),exhibit strong second-order nonlinear responses,making them ideal candidates for nonlinear photonic applications.Herein,we demonstrate a heterogeneously integrated platform combining silicon nitride waveguides with chemical vapor deposition(CVD)-grown monolayer WS_(2),enabling second harmonic generation.A specially designed silica cladding featuring gentle-slope profile on silicon nitride strip waveguides facilitates the integration of centimeter-scale WS_(2)film with photonic circuits.This approach provides a robust solution for incorporating second-order nonlinearity into silicon nitride photonic systems.The demonstrated platform holds significant potential for advancing quantum networks,visible-light lasers,and integrated optical modulation/detection systems.展开更多
Realizing the valley Hall effect by breaking the spatial inversion symmetry of photonic systems has become a cutting-edge field of micro-nano-optics,since the valley degree of freedom was introduced into photonic syst...Realizing the valley Hall effect by breaking the spatial inversion symmetry of photonic systems has become a cutting-edge field of micro-nano-optics,since the valley degree of freedom was introduced into photonic system.Various novel devices based on the domain walls of the valley photonic crystals have also been demonstrated.In this article,we investigate the variation of edge states by the modulation of refractive index within the domain walls,and the geometric difference between the dielectric columns of the sublattices.Straight photonic crystal waveguides with three types of domain walls(bearded,zigzag,armchair)are constructed.Simulation results show that the creation of a double-edge state in the band diagram results in two windows of stable transmission in tunable bands.Our findings might have significant implications in the field of novel optical devices.展开更多
The single-molecule detection tech-nique plays a pivotal role in elucidat-ing the fundamental mechanisms of various scientific processes at the molecular level,and holds essential im-portance in multiple fields includ...The single-molecule detection tech-nique plays a pivotal role in elucidat-ing the fundamental mechanisms of various scientific processes at the molecular level,and holds essential im-portance in multiple fields including physics,biology,and chemistry.Re-cently,single-molecule detection has garnered increasing attention owing to its practical utility in medical diagno-sis,primarily due to its exceptional sensitivity and the minimal sample volume required for analysis.However,the conventional single-molecule technique,represented by total internal reflection microscopy,faces challenges such as sophisticated operation procedures and limited detection throughput,thereby impeding its broader application.To address these limitations,we have demonstrated single-molecule detection using an integrated silicon photonic chip,of-fering a cost-effective and user-friendly alternative.By employing basic optics,we efficiently introduce the excitation source for single-molecule fluorescence by harnessing the strong evanescent field of high refractive-index waveguides.Subsequently,fluorescence signals are collected using basic optics comprising a water-immersion objective,relay optics,and a digi-tal camera.Our results highlight a low-cost,high-throughput single-molecule technique achieved through the integrated silicon photonic chip.This innovative approach is promised to facilitate the widespread adoption of single-molecule fluorescence in medical diagnosis.展开更多
Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attrac...Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attracted much attention^([1−3]).In 2023,Kyoto University reported GaAs-based 945 nm PCSELs with a continuous-wave(CW)single-mode output power of exceeding 50 W,and a narrow beam divergence angle of 0.05°,demonstrating a brightness of 1 GW·cm^(−2)·sr^(−1),which rivals those of the existing bulky lasers^([4]).展开更多
基金supported by the National Natural Science Foundation of China under Grant 62171233the Natural Science Foundation of China,Jiangsu Province under Grant BK20241891the Jiangsu Province Graduate Research and Practice Innovation Plan under Grants SJCX24_0313 and KYCX24_1169。
文摘A high-sensitivity,low-noise single photon avalanche diode(SPAD)detector was presented based on a 180 nm BCD process.The proposed device utilizes a p-implant layer/high-voltage n-well(HVNW)junction to form a deep avalanche multiplication region for near-infrared(NIR)sensitivity enhancement.By optimizing the device size and electric field of the guard ring,the fill factor(FF)is significantly improved,further increasing photon detection efficiency(PDE).To solve the dark noise caused by the increasing active diameter,a field polysilicon gate structure connected to the p+anode was investigated,effectively suppressing dark count noise by 76.6%.It is experimentally shown that when the active diameter increases from 5 to 10μm,the FF is significantly improved from 20.7%to 39.1%,and thus the peak PDE also rises from 13.3%to 25.8%.At an excess bias voltage of 5 V,a NIR photon detection probability(PDP)of 6.8%at 905 nm,a dark count rate(DCR)of 2.12 cps/μm^(2),an afterpulsing probability(AP)of 1.2%,and a timing jitter of 216 ps are achieved,demonstrating excellent single photon detection performance.
基金The derivation of the population coefficients in the emission induced by a plane wave are supported by the Foundation for the Advancement of Theoretical Physics and Mathematics“BASIS”The extension of these calculations to an incident vortex photon is supported by the Ministry of Science and Higher Education of the Russian Federation(Grant No.FSER-2025-0012)+2 种基金The studies of time dynamics of OAM of the entangled pair are supported by the Russian Science Foundation(Grant No.23-62-10026https://rscf.ru/en/project/23-6210026/)The studies of influence of the finite localization region of an atom on its interaction with an incident vortex photons are supported by the Russian Science Foundation(Grant No.25-71-00060)。
文摘Pairs of entangled vortex photons can promise new prospects of application in quantum computing and cryptography.We investigate the possibility of generating such states via two-level atom emission induced by a single photon wave packet with a definite total angular momentum(TAM).The entangled pair produced in this process possesses well-defined mean TAM with the TAM variation being much smaller than h.On top of that,the variation exponentially decreases with the increase in TAM of the incident photon.Our model allows one to track the time evolution of the state of the entangled pair.An experimentally feasible scenario is assumed,in which the incident photon interacts with a spatially confined atomic target.We conclude that induced emission can be used as a source of entangled vortex photons with applications in atomic physics experiments,quantum optics,and quantum information sciences.
文摘An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mode area and nonlinear coefficient were investigated by using finite element method(FEM),the evolu-tion of optical pulses propagating along the fiber was simulated,and the supercontinuum and the coherence were analyzed and evaluated under different pumping conditions.The results show that a supercontinuum spectrum with a spectral width of 4.852μm can be obtained in the proposed fiber with d_(1)/Λof 0.125,d_(2)/Λof 0.583 and the zero-dispersion wavelength of 3.228μm by pumping with a Gaussian pulse with a peak power of 800 W and a full width at half maximum(FWHM)of 20 fs at wavelength of 3.3μm.When the fiber is pumped by the pulse with the peak power of 2000 W,the FWHM of 80 fs at the wavelength of 4.0μm in the in the anomalous dispersion region,the modulation instability is obviously suppressed,and the high-coher-ence supercontinuum spectrum spanning from 1.1μm to 8.99μm is observed.A part of the pulse energy is transferred to the anomalous dispersion region when pumped at the wavelength of 2.8μm in the normal dis-persion region and a broadband high-coherence supercontinuum spectrum extending from 0.8μm to 9.8μm is generated in the 10 mm proposed fiber.This paper introduces elliptical air holes in the Al_(0.24)Ga_(0.76)As photonic crystal fiber,which enhances flexibility for tailoring the performance of supercontinuum,ultimately achieving the broadest supercontinuum spectrum with the shortest fiber length to date.
基金National Key Research and Development Program of China (2022YFB2802400)National Natural Science Foundation of China (62250010, 62090054, 62274160)Youth Innovation Promotion Association of the Chinese Academy of Sciences (2021111)。
文摘Wavelength division multiplexing technology has been pivotal in addressing the demand for high-capacity optical communication with silicon photonics providing a promising platform. This work presents a 16-channel wavelength division multiplexing silicon photonics receiver chip composed of an arrayed waveguide grating and Ge-on-Si photodetectors. Integrated inductors are introduced to enhance the high-speed performance of photodetectors, enabling data rates up to 112 Gbps with high responsivity and low dark current. The operating wavelength range of the arrayed wavelength grating is adjusted according to the response of the Ge-on-Si photodetector. The optical insertion loss, cross talk and central wavelength of the array waveguide grating are 2.1 to 3.7 d B,-12 to-15 d B, and 1538 nm, respectively. The proposed receiver chip offers a solution to meet the challenges of modern data transmission requirements.
文摘A symmetrical one-dimensional(1D)photonic crystal structure with a Dirac-emimetal-defected layer is proposed.The material properties of the Dirac semimetal are governed by three key parameters:Fermi level,Fermi velocity,and degeneracy factor.Simulation results demonstrate that the proposed structure generates multiple photonic bandgaps within the THz frequency range.In the low-THz region,pronounced resonant transmission peaks emerge,enabling near-perfect filtering performance.The positions of these defect modes can be dynamically tuned by adjusting the Fermi level and degeneracy factor.In mid-and high-THz frequency bands,the Dirac semimetal begins to exhibit metallic behavior,leading to attenuation of the transmission peaks and the appearance of absorption.The elevation of the Fermi level delays the critical threshold for the transition from the dielectric state to the metallic state,while an increase in Fermi velocity suppresses metallic behavior.Therefore,enhancing both the Fermi level and Fermi velocity contributes to strengthening the defect peak intensity.Conversely,increasing the degeneracy factor strengthens the metallic characteristics,thereby disrupting the high-frequency photonic bandgap.Notably,the defect layer thickness and incident angle exert significant influence on the transmission behavior:a larger incident angle causes the defect peak to shift toward higher frequencies and reduces its intensity,whereas a thicker defect layer shifts the defect peak toward lower frequencies.The modulation effects of both parameters become more pronounced as frequency increases.Compared with conventional photonic crystals,our work can provide a tunable structure over transmission properties,offering novel strategies for designing tunable filters and optical sensors.
基金supported by the Guangdong Basic and Applied Basic Research Foundation,China(No.2021B1515140007).
文摘The Southern Advanced Photon Source(SAPS)is a diffraction-limited synchrotron light source under design,which employs longitudinal injection as its primary injection scheme.This kind of injection scheme requires that the injected beam has a short bunch length and low emittance,and the preferred injector should offer high stability and low cost.Therefore,an injector based on a booster synchrotron was developed.The proposed injector includes a 250 MeV linac,a booster synchrotron that ramps the beam energy to 3.5 GeV,and two beam transport lines to ensure efficient beam delivery and beam quality preservation.The linac utilizes a thermionic high-voltage DC gun for reliable operation and features a bunching system with an advanced focusing system to preserve the emittance.To meet the injection requirements of the SAPS,a comprehensive design for the booster has been conducted.The booster synchrotron employs a threefold lattice structure,incorporating modified theoretical minimum emittance cells with a small momentum compaction factor and a high voltage to achieve an emittance of 3.98 nm rad and a bunch length of 4.8 mm.The injector has the potential to deliver a high charge,reducing the injection period of the storage ring to less than 1 min.Simulations demonstrated the expected performance,with a transmission efficiency of 90%,confirming its capability to meet the injection requirement of the SAPS storage ring.This design offers a stable and efficient solution for the SAPS.
基金support of the National Natural Science Foundation of China(grant 22508184 to X.Q.Y.,grant 21736006 to S.C.,and grant 22278225 to S.C.)supported by the Natural Funding Program of Jiangsu Province(grant BK20250610 to X.Q.Y.).
文摘Methods allowing passive daytime radiative cooling(PDRC)to be carried out in an energy-efficient and scalable way are potentially important for various disciplines.Here,we report a sustainable strategy for scalable-designed and color-regulating PDRC coating based on high-crystallinity photonic metamaterial(crystallinity:71.5%;enhanced assembly efficiency:72%),that is derived from the as-prepared 55 wt%solid content poly(methyl methacrylate-butyl acrylate-methacrylic acid)P(MMA-BA-MAA)monodispersed latexes(approaching theoretical limit:59 wt%).Robust meter-scale PDRC coatings are constructed by various industrial modes onto diverse surfaces,addressing bottlenecks like dull appearance,high cost,low efficiency,and hard construction.Notably,the solar reflectance,long-wave infrared emittance,and calculated theoretical cooling power of the designed PDRC coating,respectively,reach~0.94,~0.97,and~95.5 W m^(-2)under solar radiation,which can achieve an average 5.3℃sub-ambient daytime temperature drop in the summer in Nanjing.The cooling performance,scale preparation,and cost-effectiveness of the PDRC coating have extended into leading position compared with those of state-of-the-art designs.This work provides promising route to reduce carbon emissions and energy consumption for global sustainability.
基金supported by the National Natural Science Foundation of China (Grant Nos.12494604,12393834,12393831,62274014,6223501662335015)the National Key R&D Program of China (Grant No.2024YFA1208900)。
文摘The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.
基金supported by the National Natural Science Foundation of China(No.62375031)the Basic Research Project of Chongqing Science and Technology Commission(No.CSTC-2021jcyj-bsh0194)the Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJQN202200602)。
文摘In this paper,a terahertz slotted waveguide array antenna is designed based on photonic crystal,which can realize efficient radiation of terahertz waves.The electromagnetic wave is fed from the rectangular waveguide at the bottom of the antenna,coupled to photonic crystal waveguide through photonic crystal cavity,and radiated outward through slots at the top layer of antenna.The simulation results show that the antenna achieves a peak gain of 13.45 dBi at 360 GHz,a half-power beam width of 10.9°,and a side lobe level of−13.9 dB.The antenna based on photonic crystal has the advantages of low profile,low loss,and high radiation efficiency,which can be applied to terahertz wireless communication systems.
基金Ministry of Electronics and Information Technology(GG-11/15/2020/EMCD)。
文摘A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of concept.For this purpose,we have investigated the programmable photonic integrated circuit comprising 14 tunable balanced Mach–Zehnder interferometers designed into a square mesh architecture and fabricated using CMOS-compatible silicon photonic technology.
基金supported by the National Key R&D Program of China(Grant No.2024YFB3614600)the National Natural Science Foundation of China(Grant No.52402185)+1 种基金Guangzhou Basic and Applied Basic Research Foundation(Grant No.2025A1515011800)Shenzhen Science and Technology Program(Grant No.JCYJ20241202123712017)。
文摘The bidirectional convergence of artificial intelligence and nanophotonics drives photonic technologies toward unprecedented levels of intelligence and efficiency,fundamentally reshaping their design paradigms and application boundaries.With its powerful data-driven and nonlinear optimization capabilities,artificial intelligence has become a powerful tool for optical design,enabling the inverse design of nanophotonics devices while accelerating the forward computation of electromagnetic responses.Conversely,nanophotonics provides a wave-based computational platform,giving rise to novel optical neural networks that achieve high-speed parallel computing and efficient information processing.This paper reviews the latest progress in the bidirectional field of artificial intelligence and nanophotonics,analyzes the basic principles of various applications from a universal perspective,comprehensively evaluates the advantages and limitations of different research methods,and makes a forwardlooking outlook on the bidirectional integration of artificial intelligence and nanophotonics,focusing on analyzing future development trends,potential applications,and challenges.The deep integration of artificial intelligence and nanophotonics is ushering in a new era for photonic technologies,offering unparalleled opportunities for fundamental research and industrial applications.
基金supported by the National Natural Science Foundation of China(62035003 and 62235009).
文摘Artificial intelligence(AI)has taken breathtaking leaps forward in recent years,evolving into a strategic technology for pioneering the future.The growing demand for computing power—especially in demanding inference tasks,exemplified by generative AI models such as ChatGPT—poses challenges for conventional electronic computing systems.Advances in photonics technology have ignited interest in investigating photonic computing as a promising AI computing modality.Through the profound fusion of AI and photonics technologies,intelligent photonics is developing as an emerging interdisciplinary field with significant potential to revolutionize practical applications.Deep learning,as a subset of AI,presents efficient avenues for optimizing photonic design,developing intelligent optical systems,and performing optical data processing and analysis.Employing AI in photonics can empower applications such as smartphone cameras,biomedical microscopy,and virtual and augmented reality displays.Conversely,leveraging photonics-based devices and systems for the physical implementation of neural networks enables high speed and low energy consumption.Applying photonics technology in AI computing is expected to have a transformative impact on diverse fields,including optical communications,automatic driving,and astronomical observation.Here,recent advances in intelligent photonics are presented from the perspective of the synergy between deep learning and metaphotonics,holography,and quantum photonics.This review also spotlights relevant applications and offers insights into challenges and prospects.
基金supported by NSFC(22271282)the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences with the grant number of CXZX-2022-JQ04.
文摘Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant Nos.2020B0301030008 and 2023A1515010416)the National Natural Science Foundation of China(Grant Nos.12375073,12275091,12147128,and 12035007).
文摘We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.
文摘The combining microelectronic devices and associated technologies onto a single silicon chip poses a substantial challenge.However,in recent years,the area of silicon photonics has experienced remarkable advancements and notable leaps in performance.The performance of silicon on insulator(SOI)based photonic devices,such as fast silicon optical modulators,photonic transceivers,optical filters,etc.,have been discussed.This would be a step forward in creating standalone silicon photonic devices,strengthening the possibility of single on-chip nanophotonic integrated circuits.Suppose an integrated silicon photonic chip is designed and fabricated.In that case,it might drastically modify these combined photonic component costs,power consumption,and size,bringing substantial,perhaps revolutionary,changes to the next-generation communications sector.Yet,the monolithic integration of photonic and electrical circuitry is a significant technological difficulty.A complicated set of factors must be carefully considered to determine which application will have the best chance of success employing silicon-based integrated product solutions.The processing limitations connected to the current process flow,the process generation(sometimes referred to as lithography node generation),and packaging requirements are a few of these factors to consider.This review highlights recent developments in integrated silicon photonic devices and their proven applications,including but not limited to photonic waveguides,photonic amplifiers and filters,onchip photonic transceivers,and the state-of-the-art of silicon photonic in multidimensional quantum systems.The investigated devices aim to expedite the transfer of silicon photonics from academia to industry by opening the next phase in on-chip silicon photonics and enabling the application of silicon photonic-based devices in various optical systems.
基金supported by the Baima Lake Laboratory Joint Fund of the Zhejiang Provincial Natural Science Foundation of China(Grant No.LBMHY25A040002)the National Natural Science Foundation of China(Grant Nos.12304472 and 12304557)+1 种基金the Funds of the Natural Science Foundation of Hangzhou(Grant No.2024SZRYBF050004)the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.ZCLQN25A0401 and ZCLZ25F0502).
文摘The investigation of topological transitions has opened up unprecedented avenues for scientific exploration in photonic metamaterials.However,previous studies mainly focused on exploring different types of three-dimensional(3D)equifrequency surfaces and their topological transition processes in magnetic topological systems.In this work,we study the multiple photonic topological transitions and dual-frequency photonic Weyl points in the topological chiral metamaterials.Through effective medium theory and topological band theory,we systematically characterize and draw comprehensive topological phase diagrams associated with diverse 3D equifrequency surface configurations in nonmagnetic photonic systems.We further demonstrate that the resonance frequencyω0 and dual-frequency Weyl points are the critical points of these topological transitions.Notably,when the vacuum state is in contact with the phases I or III chiral metamaterials,the high-local and frequency chirality-dependent topological Fermi arc surface states arise.We reveal that the parameterωcan be used as a degree of freedom to regulate the bandwidth of such topological surface states.Moreover,different types of multichannel and directional topological photonic routings are achieved using the chirality-dependent Fermi arc surface states.We theoretically show that the physical mechanism of achieving these multichannel topological photonic routings is caused by the different interface properties.We could offer promising perspectives on 3D topological semimetal systems and provide more adaptability for multichannel devices in the nonmagnetic continuous media.
基金Project supported by the National Innovative Training Program for College Students of China(Grant No.2023069)the University Research and Innovation Project of the National University of Defense Technology。
文摘Silicon nitride photonics has emerged as a promising integrated optical platform due to its broad transparency window,low optical loss,and mature fabrication technology.However,the inherent centrosymmetric crystal structure of silicon nitride fundamentally restricts its applications in second-order nonlinear optical processes.Monolayer transition metal dichalcogenides,particularly tungsten disulfide(WS_(2)),exhibit strong second-order nonlinear responses,making them ideal candidates for nonlinear photonic applications.Herein,we demonstrate a heterogeneously integrated platform combining silicon nitride waveguides with chemical vapor deposition(CVD)-grown monolayer WS_(2),enabling second harmonic generation.A specially designed silica cladding featuring gentle-slope profile on silicon nitride strip waveguides facilitates the integration of centimeter-scale WS_(2)film with photonic circuits.This approach provides a robust solution for incorporating second-order nonlinearity into silicon nitride photonic systems.The demonstrated platform holds significant potential for advancing quantum networks,visible-light lasers,and integrated optical modulation/detection systems.
基金supported by the Self-Deployment Project Research Program of the Haixi Institutes,Chinese Academy of Sciences(No.CXZX-2022-GH09)the National Natural Science Foundation of China(No.11774103)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR114)。
文摘Realizing the valley Hall effect by breaking the spatial inversion symmetry of photonic systems has become a cutting-edge field of micro-nano-optics,since the valley degree of freedom was introduced into photonic system.Various novel devices based on the domain walls of the valley photonic crystals have also been demonstrated.In this article,we investigate the variation of edge states by the modulation of refractive index within the domain walls,and the geometric difference between the dielectric columns of the sublattices.Straight photonic crystal waveguides with three types of domain walls(bearded,zigzag,armchair)are constructed.Simulation results show that the creation of a double-edge state in the band diagram results in two windows of stable transmission in tunable bands.Our findings might have significant implications in the field of novel optical devices.
基金supported by the National Key Research and Development Program(No.2022YFE0107400)the internal research funding from Photonic View Technology Technology Co.,Ltd.the GuangCi Deep Mind Project of Ruijin Hospital Shanghai Jiao Tong University School of Medicine.
文摘The single-molecule detection tech-nique plays a pivotal role in elucidat-ing the fundamental mechanisms of various scientific processes at the molecular level,and holds essential im-portance in multiple fields including physics,biology,and chemistry.Re-cently,single-molecule detection has garnered increasing attention owing to its practical utility in medical diagno-sis,primarily due to its exceptional sensitivity and the minimal sample volume required for analysis.However,the conventional single-molecule technique,represented by total internal reflection microscopy,faces challenges such as sophisticated operation procedures and limited detection throughput,thereby impeding its broader application.To address these limitations,we have demonstrated single-molecule detection using an integrated silicon photonic chip,of-fering a cost-effective and user-friendly alternative.By employing basic optics,we efficiently introduce the excitation source for single-molecule fluorescence by harnessing the strong evanescent field of high refractive-index waveguides.Subsequently,fluorescence signals are collected using basic optics comprising a water-immersion objective,relay optics,and a digi-tal camera.Our results highlight a low-cost,high-throughput single-molecule technique achieved through the integrated silicon photonic chip.This innovative approach is promised to facilitate the widespread adoption of single-molecule fluorescence in medical diagnosis.
基金funded by National Key R&D Program of China(Grant Nos.2024YFB3612200,2023YFB3609601,2022YFB3604300,2022YFB2802801,2022YFB3604802)Natural Science Foundation of China(Grant Nos.U24A20300,62174174,62274177,62275263,62325406,62374172,62304242,62304240,62404241)+4 种基金Youth Innovation Promotion Association of CAS(Grant Nos.2022323 and 2022324)Key R&D Program of Jiangsu Province(Grant No.BE2023018-2)Basic Research Program of Jiangsu(Grant No.BK20240126)Suzhou Science and Technology Program(Grant Nos.SYC2022089,ZXL2024379,and ZXL2024376)Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2022A1515110482 and 2022A1515110004).
文摘Photonic crystal surface emitting lasers(PCSELs)utilize the Bragg diffraction of two-dimensional photonic crystals to achieve a single-mode output with a high power and a small divergence angle,and has recently attracted much attention^([1−3]).In 2023,Kyoto University reported GaAs-based 945 nm PCSELs with a continuous-wave(CW)single-mode output power of exceeding 50 W,and a narrow beam divergence angle of 0.05°,demonstrating a brightness of 1 GW·cm^(−2)·sr^(−1),which rivals those of the existing bulky lasers^([4]).
