To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.T...To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.This source is based on spontaneous four-wave mixing(SFWM)in a piece of shallow-ridge silicon waveguide.Theoretical analysis shows that the waveguide dispersion could be tailored by adjusting the ridge width,enabling broadband photon pair generation by SFWM across C band and O band.The spontaneous Raman scattering(SpRS)in silicon waveguides is also investigated experimentally.It shows that there are two regions in the spectrum of generated photons from SpRS,which could be used to achieve cross-band photon pair generation.A chip of shallow-ridge silicon waveguide samples with different ridge widths has been fabricated,through which cross-band photon pair generation is demonstrated experimentally.The experimental results show that the source can be achieved using dispersion-optimized shallow-ridge silicon waveguides.This cross-band quantum light source provides a way to develop new fiber-based quantum communication functions utilizing both C band and O band and extends applications of quantum networks.展开更多
Silicon-based phototransistor detectors,offering advantages such as high internal gain,cost-effective and compatibility with CMOS technology,are becoming one of the key devices for large-scale photon integration chip ...Silicon-based phototransistor detectors,offering advantages such as high internal gain,cost-effective and compatibility with CMOS technology,are becoming one of the key devices for large-scale photon integration chip and have significant potential for applications in short-distance optical interconnecting.To relieve its inherent optimization contradiction between responsivity and bandwidth performance,a novel couple ridge waveguide SiGe/Si phototransistor was proposed,in which the carrier transport and the photon propagation were perpendicu⁃lar and demonstrate the independent optimization on absorption efficiency and operating speed.The optical propa⁃gation mode in the SiGe/Si ridge waveguide were analyzed between the single mode and the multiple mode.The geometric parameters of the ridge waveguide to achieve high absorption efficiency were optimized.The ridge waveguide SiGe/Si phototransistor were fabricated using technology compatible with CMOS process platform and achieved a responsivity of 6.4 A/W with the dark current of 10 nA.展开更多
Although multicrystalline Si photovoltaics have been extensively studied and applied in the collection of solar energy,the same systems suffer significant efficiency losses in indoor settings,where ambient light condi...Although multicrystalline Si photovoltaics have been extensively studied and applied in the collection of solar energy,the same systems suffer significant efficiency losses in indoor settings,where ambient light conditions are considerably smaller in intensity and possess greater components of non-normal incidence.Yet,indoor light-driven,stand-alone devices can offer sustainable advances in next-generation technologies such as the Internet of Things.Here,we present a non-invasive solution to aid in photovoltaic indoor light collection—radially distributed waveguide-encoded lattice(RDWEL)slim films(thickness 1.5 mm).Embedded with a monotonical radial array of cylindrical waveguides(±20°),the RDWEL demonstrates seamless light collection(FoV(fields of view)=74.5°)and imparts enhancements in JSC(short circuit current density)of 44%and 14%for indoor and outdoor lighting conditions,respectively,when coupled to a photovoltaic device and compared to an unstructured but otherwise identical slim film coating.展开更多
Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior a...Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior and mechanical property of molecular crystals simultaneously via supramolecular salt strategy is rarely reported,which is very important to improve their photophysical behavior and softness for the fabrication of flexible light-emitting device.Herein,supramolecular salt approach has been successfully applied to synthesize two elastic organic fluorescent crystals(CMOH-Py-Cl and CMOH-Py-Br)derived from non-emissive and brittle pyridine-substituted coumarin derivative(CMOH-Py).Their elastic properties can be attributed to the prevalent presence of numerous weak interactions introduced by halogen atoms,which are beneficial to the absorption and release of mechanical energy.Furthermore,density functional theory(DFT)calculations demonstrated a narrowing of the HOMO-LUMO energy gaps from CMOH-Py to CMOH-Py-Cl/CMOH-Py-Br via supramolecular salt approach.Finally,the application of flexible crystal materials in the field of optical waveguides has been investigated.The transformation of crystals in terms of photophysical and mechanical properties,achieved by the supramolecular salt approach,offers novel insights into the design and construction of flexible crystalline materials,providing a new path for the development of next-generation smart materials.展开更多
We present a non-local quantum system based on a waveguide QED architecture,comprising two spatially separated and largely detuned superconducting transmon qubits.By applying parametric frequency modulation to one of ...We present a non-local quantum system based on a waveguide QED architecture,comprising two spatially separated and largely detuned superconducting transmon qubits.By applying parametric frequency modulation to one of the qubits,we establish a tunable coherent channel between the two far-detuned qubits,thereby forming anΛ-type three-level system.We demonstrate that tuning the modulation amplitude enables the observation of spectral evolution from electromagnetically induced transparency(EIT)to Autler–Townes splitting(ATS).Furthermore,by exploiting the interplay between the non-local waveguide phase and system dissipation,the system achieves significant non-reciprocal microwave transmission and direction-selective photon emission.The scheme operates without external magnetic fields,offering an efficient pathway for realizing on-chip integrated quantum routers and isolators.展开更多
Extending the operational wavelength range of integrated optical devices to cover the entire vis-ible spectrum holds significant importance,as it can enhance the detection accuracy and applicability of mini-aturized s...Extending the operational wavelength range of integrated optical devices to cover the entire vis-ible spectrum holds significant importance,as it can enhance the detection accuracy and applicability of mini-aturized spectrometers,broaden the bandwidth of visible light communication,and enable biosensors to sim-ultaneously detect multiple biomolecules in complex samples.As the fundamental building block of integ-rated optical devices,waveguides have not yet been thoroughly investigated for full visible spectrum opera-tion.This work presents a waveguide design supporting the full visible spectrum(435−760 nm).Numerical simulations were employed to analyze the transmission characteristics of various waveguide structures,re-vealing that single-mode propagation cannot be achieved across the entire visible spectrum.Under mul-timode propagation conditions,key parameters such as propagation loss and mode distribution were system-atically examined to determine the optimal waveguide dimensions,bending radii,and waveguide spacings for low-loss transmission.For slab waveguides,a thickness≥1μm ensures polarization insensitivity.For strip waveguides with a thickness of 1μm,a width≥2μm significantly reduces scattering loss induced by side-wall roughness.For strip waveguides with a width of 1μm and thickness of 2μm,radiation loss becomes negligible when the bending radius≥10μm and waveguide spacing≥0.4μm,while maintaining effective isolation from adjacent waveguides.Additionally,the impact of fabrication tolerances on waveguide per-formance was evaluated.In contrast to previous studies primarily focusing on narrow spectral bands within the visible range,the proposed design enables full visible spectrum transmission in a single waveguide,thereby facilitating bandwidth expansion and performance enhancement for on-chip full visible spectrum devices.展开更多
Owing to its compact footprint and superior filter properties,the Bragg grating filter is attractive for applications in optical communications.In this research,we conducted a detailed analysis of the influence of Bra...Owing to its compact footprint and superior filter properties,the Bragg grating filter is attractive for applications in optical communications.In this research,we conducted a detailed analysis of the influence of Bragg grating parameters on its functionality and experimentally validated our findings on a simple and low-cost polymer/silica hybrid waveguide platform.The best extinction ratio of 26.3 dB is obtained when the period is 6.63µm and the number of periods is 200.The full width at half maximum of the grating is 0.35 nm at 1544.74 nm.Tuning efficiency reaches 29.6 pm/mW owing to the high thermo-optical efficiency of the polymer.Finally,we measure the rise and fall times of the grating to be 280µs.The proposed grating shows great potential in flexible and reconfigurable optical networks.展开更多
We investigate the nonlinear Goos-Hanchen shift of a light beam reflected from a prism-coupled leaky waveguide containing a Kerr medium.As the incident power varies,the system can switch between two states,total inter...We investigate the nonlinear Goos-Hanchen shift of a light beam reflected from a prism-coupled leaky waveguide containing a Kerr medium.As the incident power varies,the system can switch between two states,total internal reflection and frustrated total reflection,owing to the inherent positive feedback arising from the intensity-dependent guiding mode resonance.The reflectance exhibits optical bistability;meanwhile,the lateral shift of the reflected beam also shows hysteresis behavior.It is found that the transition between the two stable states is related to the excitation of a leaky mode in the waveguide,which results from the modulation of the electric field in the nonlinear substrate.We also analyze the effects of system parameters on the bistable Goos-Hanchen shift.The thresholds as well as the width of the hysteresis curve are sensitive to the thicknesses of the gap layer and the guiding layer,which determine the resonance angle.The bistable lateral displacement in the slab waveguide may have potential applications in optical switching,beam steering,etc.展开更多
A millimeter-wave(mm-Wave)dual circularly polarized(CP)antenna in gap waveguide(GWG)technology with high port isolation is proposed in this paper.It is consisted of a simplified orthomode transducer(OMT)and an improve...A millimeter-wave(mm-Wave)dual circularly polarized(CP)antenna in gap waveguide(GWG)technology with high port isolation is proposed in this paper.It is consisted of a simplified orthomode transducer(OMT)and an improved multi-section hexagonal waveguide CP horn antenna.The OMT is composed of two metal layers without the traditional septum or iris,which makes the structure simpler.The CP horn antenna can be easily integrated with the OMT without mode conversion.The principle analysis as well as the simulated and measured results of the proposed antenna are given in this paper.The simulated and measured results agree very well with each other.The port isolation of more than 27 dB over bandwidth of 26.5-31 GHz(|S11|<-15 dB)is achieved with relative bandwidth of 15.7%.The axial ratio(AR)lower than 2.5 dB for both left-hand and righthand CP(LHCP and RHCP)are achieved over the bandwidth.The proposed antenna is a candidate for mm-Wave satellite communications or beyond fifth-generation(5G)communications applications.展开更多
Commercial augmented reality(AR)glasses commonly employ geometrical or diffractive optical waveguides,which,despite their compact form factor,typically suffer from low optical efficiency.To achieve both thin form and ...Commercial augmented reality(AR)glasses commonly employ geometrical or diffractive optical waveguides,which,despite their compact form factor,typically suffer from low optical efficiency.To achieve both thin form and high efficiency,for the first time,an AR optical waveguide based on a microprism is proposed.A deep-learning-assisted hardware±software cooptimization framework is introduced to expand the system's design freedom and enable end-to-end joint optimization between the microprism waveguide and the image preprocessing algorithm.Simulation results demonstrate that the proposed system achieves an overall thickness of only 8 mm,an optical efficiency of approximately 44.3%,high imaging quality,and a binocular field of view of 36°.This work provides a new pathway toward high-performance and ultra-thin AR display systems.展开更多
Leveraging the natural axial confinement of coherent extreme ultraviolet(EUV)light generated via the high-order harmonic generation process,we demonstrate the spatial separation of EUV and the driving infrared(IR)beam...Leveraging the natural axial confinement of coherent extreme ultraviolet(EUV)light generated via the high-order harmonic generation process,we demonstrate the spatial separation of EUV and the driving infrared(IR)beams through hollow-core microchannels embedded in a laser machine glass device.This structure enables broadband EUV transmission while attenuating the collinear IR by 2 orders of magnitude.In addition,we explore the potential of integrated photonic architectures based on EUV-guiding hollow structures,laying the foundation for a new class of compact,palm-top devices for EUV and soft X-ray 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 triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication chan...A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication channels and less antenna sizes,multi-band antennas are currently under intensive investigation.By a novel feeding method,three odd modes are excited on an SSPP waveguide resonator,which performs as an end-fire antenna operating at three bands,7.15-7.26 GHz,11.6-12.2 GHz and 13.5-13.64 GHz.It exhibits reasonably high and stable maximum gains of 5.26 dBi,7.97 dBi and 10.1 dBi and maximum efficiencies of 64%,92%and 98%at the three bands,respectively.Moreover,in the second band,the main beam angle shows a frequency dependence with a total scanning angle of 19°.The miniaturized triple-band antenna has a great potential in wireless communication systems,satellite communication and radar systems.展开更多
A plasmonics waveguide structure that consist of a non-through metal–insulator–metal(MIM)waveguide coupled with a D-shaped cavity was designed.And the transmission properties,magnetic field distribution,and refracti...A plasmonics waveguide structure that consist of a non-through metal–insulator–metal(MIM)waveguide coupled with a D-shaped cavity was designed.And the transmission properties,magnetic field distribution,and refractive index sensing functionality were simulated using the finite element method(FEM).A multi-Fano resonance phenomenon was clearly observable in the transmission spectra.The Fano resonances observed in the proposed structure arise from the interaction between the discrete states of the Dshaped resonant cavity and the continuum state of the non-through MIM waveguide.The influence of structural parameters on Fano resonance modulation was investigated through systematic parameter adjustments.Additionally,the refractive index sensing properties,based on the Fano resonance,were investigated by varying the refractive index of the MIM waveguide's insulator layer.A maximum sensitivity and FOM of 1155 RIUm and 40 were achieved,respectively.This research opens up new possibilities for designing and exploring high-sensitivity photonic devices,micro-sensors,and innovative on-chip sensing architectures for future applications.展开更多
Compared to existing deformation monitoring methods,landslide early warning can be achieved by detecting precursor signals of slope instability through acoustic emission(AE).Acquisition of AE signals generated by acti...Compared to existing deformation monitoring methods,landslide early warning can be achieved by detecting precursor signals of slope instability through acoustic emission(AE).Acquisition of AE signals generated by active waveguide facilitates monitoring the development of shear surface and provides a foundation for quantifying landslide movement.Backfill particles are the dominant AE sources in active waveguides,typically chosen from materials such as gravels or sands.However,the influence of particle sizes and gradings has not been clarified in existing laboratory models or field monitoring.This research introduces a direct shear test for active waveguide,where spherical glass beads are employed to precisely regulate the size and grading of backfill particles.A programmable logic controller maintains a constant shearing speed and equivalent total deformation.Through a comprehensive analysis of AE,deformation,and mechanical measurements,this study evaluates the impact of particle size and grading on monitoring capabilities.The findings suggest that the AE mechanism in glass beads is attributed to particle collision and dislocation,leading to AE events characterized by low amplitude and energy levels.The percentage of high-amplitude AE events rises steadily with the progression of shearing.The correlation between shear force,cumulative ring down count(RDC)of AE,and deformation conforms to a power function,with the exponent relying on particle size,grading,and shearing speed.Notably,the combination of small particles and low shearing speeds can yield the maximum cumulative RDC,while selecting particles with uneven grading will significantly enhance the intensity of AE signals from active waveguide.展开更多
Ferrimagnetic materials exhibiting remanence can be used to achieve unidirectional electromagnetic-field propagation in the form of magnetoplasmons(MPs)in the subwavelength regime.This study investigates the MP proper...Ferrimagnetic materials exhibiting remanence can be used to achieve unidirectional electromagnetic-field propagation in the form of magnetoplasmons(MPs)in the subwavelength regime.This study investigates the MP properties and various guiding modes in a hollow cylindrical waveguide made of materials that exhibit remanence.Pattern analysis and numerical simulations are used to demonstrate that dispersion relationships and electromagnetic-field distribution are strongly affected by the operating frequency and physical dimensions of the structure.In addition,the existence of two different guiding modes is proved,namely regular and surface-wave modes.By adjusting the operating frequency and reducing the diameter of the hollow cylinder,the regular mode can be suppressed so as to only retain the surface-wave mode,which enables unidirectional MP propagation in the cylindrical waveguide.Moreover,the unidirectional surface-wave mode is robust to backscattering due to surface roughness and defects,which makes it very useful for application in field-enhancement devices.展开更多
Integrating the magneto-optical effect into a waveguide-based photonic device becomes more and more interesting.In the work,the planar optical waveguide firstly was prepared in a terbium gallium garnet crystal(TGG)via...Integrating the magneto-optical effect into a waveguide-based photonic device becomes more and more interesting.In the work,the planar optical waveguide firstly was prepared in a terbium gallium garnet crystal(TGG)via the proton implantation with the energy of 4×10-1MeV and the fluence of 6×108ions/μm2.Subsequently,a femtosecond laser with a central wavelength of 800 nm and a power of 3 mW was used to ablate the surface of the planar waveguide,forming the ridge optical waveguide.The dark-mode curve of the planar waveguide was measured by a prism coupling technique.The top-view morphology of the ridge waveguide was observed via a Nikon microscope.The mode field distributions of the planar and ridge waveguides were obtained by an end-face coupling system,and the propagation losses of the two waveguides were measured to be 2.26 dB/cm and 2.58 dB/cm,respectively.The Verdet constants were measured to be-72.7°/T·cm for the TGG substrate and-60.7°/T·cm for the ridge waveguide.The TGG waveguides have a potential in the fabrication of magneto-optical waveguide devices.展开更多
In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particul...In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particularly pronounced with an increase in ridge width,resulting in multimode problems.To tackle this,an innovative multi ridge waveguide structure based on the principle of supersymmetry(SUSY)was proposed.This structure comprises a wider main waveguide in the center and two narrower auxiliary waveguides on either side.The high-order modes of the main waveguide are coupled with the modes of the auxiliary waveguides through mode-matching design,and the optical loss of the auxiliary waveguides suppresses these modes,thereby achieving fundamental mode lasing of the wider main waveguide.This paper employs the finite difference eigenmode(FDE)method to perform detailed structural modeling and simulation optimization of the 4.6μm wavelength quantum cascade laser,successfully achieving a single transverse mode QCL with a ridge width of 10μm.In comparison to the traditional single-mode QCL(with a ridge width of about 5μm),the MRW structure has the potential to increase the gain area of the laser by 100%.This offers a novel design concept and methodology for enhancing the single-mode luminous power of mid-infrared quantum cascade lasers,which is of considerable significance.展开更多
The phase-controlled single-photon transport properties of a giant atom coupled to a one-dimensional waveguide are investigated.The coupling between the giant atom and the waveguide is modeled as a multi-point interac...The phase-controlled single-photon transport properties of a giant atom coupled to a one-dimensional waveguide are investigated.The coupling between the giant atom and the waveguide is modeled as a multi-point interaction.The coupling strengths between the giant atom and the waveguide are represented as complex numbers with associated phases.Analytical expressions for the scattering amplitudes are obtained using the real-space Hamiltonian method.The results show that the characteristics of the scattering spectra,including the positions of peaks(or dips)and the full width at half maximum,can be tuned by adjusting the phase difference between the coupling strengths.Further calculations reveal that the scattering spectra can be either super-broadened or sub-broadened.The conditions for achieving perfect nonreciprocal single-photon transport in the Markovian regime are also discussed.Moreover,we demonstrate the control of single-photon transport through phase differences in the non-Markovian regime.Our results may find applications in the design of quantum devices operating at the single-photon level,based on waveguide quantum electrodynamics.展开更多
Diffractive optical neural networks(DONNs)have exhibited the advantages of parallelization,high speed,and low consumption.However,the existing DONNs based on free-space diffractive optical elements are bulky and unste...Diffractive optical neural networks(DONNs)have exhibited the advantages of parallelization,high speed,and low consumption.However,the existing DONNs based on free-space diffractive optical elements are bulky and unsteady.In this study,we propose a planar-waveguide integrated diffractive neural network chip architecture.The three diffractive layers are engraved on the same side of a quartz wafer.The three-layer chip is designed with 32-mm3 processing space and enables a computing speed of 3.1×109 Tera operations per second.The results show that the proposed chip achieves 73.4%experimental accuracy for the Modified National Institute of Standards and Technology database while showing the system’s robustness in a cycle test.The consistency of experiments is 88.6%,and the arithmetic mean standard deviation of the results is~4.7%.The proposed chip architecture can potentially revolutionize high-resolution optical processing tasks with high robustness.展开更多
基金supported by the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2024ZD0302502 for WZ)the National Natural Science Foundation of China(Grant No.92365210 for WZ)+1 种基金Tsinghua Initiative Scientific Research Program (for WZ)the project of Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies (JIAOT,for YH)。
摘要To fully utilize the resources provided by optical fiber networks,a cross-band quantum light source generating photon pairs,where one photon in a pair is at C band and the other is at O band,is proposed in this work.This source is based on spontaneous four-wave mixing(SFWM)in a piece of shallow-ridge silicon waveguide.Theoretical analysis shows that the waveguide dispersion could be tailored by adjusting the ridge width,enabling broadband photon pair generation by SFWM across C band and O band.The spontaneous Raman scattering(SpRS)in silicon waveguides is also investigated experimentally.It shows that there are two regions in the spectrum of generated photons from SpRS,which could be used to achieve cross-band photon pair generation.A chip of shallow-ridge silicon waveguide samples with different ridge widths has been fabricated,through which cross-band photon pair generation is demonstrated experimentally.The experimental results show that the source can be achieved using dispersion-optimized shallow-ridge silicon waveguides.This cross-band quantum light source provides a way to develop new fiber-based quantum communication functions utilizing both C band and O band and extends applications of quantum networks.
基金Supported by the National Natural Science Foundation of China(62475005,62271014)the Beijing Municipal Natural Science Founda⁃tion(4232062,4192014)the Shandong Province Natural Science Foundation(ZR2021MF077)。
摘要Silicon-based phototransistor detectors,offering advantages such as high internal gain,cost-effective and compatibility with CMOS technology,are becoming one of the key devices for large-scale photon integration chip and have significant potential for applications in short-distance optical interconnecting.To relieve its inherent optimization contradiction between responsivity and bandwidth performance,a novel couple ridge waveguide SiGe/Si phototransistor was proposed,in which the carrier transport and the photon propagation were perpendicu⁃lar and demonstrate the independent optimization on absorption efficiency and operating speed.The optical propa⁃gation mode in the SiGe/Si ridge waveguide were analyzed between the single mode and the multiple mode.The geometric parameters of the ridge waveguide to achieve high absorption efficiency were optimized.The ridge waveguide SiGe/Si phototransistor were fabricated using technology compatible with CMOS process platform and achieved a responsivity of 6.4 A/W with the dark current of 10 nA.
基金supported by the European Research Council(ERC)under the European Union's Horizon 2020 Research and Innovation Programme(Grant Agreement No.818762)the Engineering and Physical Sciences Research Council(Grant No.EP/V048953/1)and the Isaac Newton Trust(grant 22.39(m))。
摘要Although multicrystalline Si photovoltaics have been extensively studied and applied in the collection of solar energy,the same systems suffer significant efficiency losses in indoor settings,where ambient light conditions are considerably smaller in intensity and possess greater components of non-normal incidence.Yet,indoor light-driven,stand-alone devices can offer sustainable advances in next-generation technologies such as the Internet of Things.Here,we present a non-invasive solution to aid in photovoltaic indoor light collection—radially distributed waveguide-encoded lattice(RDWEL)slim films(thickness 1.5 mm).Embedded with a monotonical radial array of cylindrical waveguides(±20°),the RDWEL demonstrates seamless light collection(FoV(fields of view)=74.5°)and imparts enhancements in JSC(short circuit current density)of 44%and 14%for indoor and outdoor lighting conditions,respectively,when coupled to a photovoltaic device and compared to an unstructured but otherwise identical slim film coating.
基金supported by the National Natural Science Foundation of China(Nos.22205105,61874053,22075136)National Key Basic Research Program of China(No.2020YFA0709900)Jiangsu Provincial Postgraduate Scientific Research Innovation Program(No.KYCX24_1649).
摘要Improving the optoelectronic behavior and stress-deformation stability of conjugated materials is crucial for the realization of their potential applications in flexible optoelectronics.To tune the emission behavior and mechanical property of molecular crystals simultaneously via supramolecular salt strategy is rarely reported,which is very important to improve their photophysical behavior and softness for the fabrication of flexible light-emitting device.Herein,supramolecular salt approach has been successfully applied to synthesize two elastic organic fluorescent crystals(CMOH-Py-Cl and CMOH-Py-Br)derived from non-emissive and brittle pyridine-substituted coumarin derivative(CMOH-Py).Their elastic properties can be attributed to the prevalent presence of numerous weak interactions introduced by halogen atoms,which are beneficial to the absorption and release of mechanical energy.Furthermore,density functional theory(DFT)calculations demonstrated a narrowing of the HOMO-LUMO energy gaps from CMOH-Py to CMOH-Py-Cl/CMOH-Py-Br via supramolecular salt approach.Finally,the application of flexible crystal materials in the field of optical waveguides has been investigated.The transformation of crystals in terms of photophysical and mechanical properties,achieved by the supramolecular salt approach,offers novel insights into the design and construction of flexible crystalline materials,providing a new path for the development of next-generation smart materials.
基金supported by the National Natural Science Foundation of China(Grant Nos.12574540,92265207,T2121001)Quantum Science and Technology–National Science and Technology Major Project of China(Grant No.2021ZD0301800)。
摘要We present a non-local quantum system based on a waveguide QED architecture,comprising two spatially separated and largely detuned superconducting transmon qubits.By applying parametric frequency modulation to one of the qubits,we establish a tunable coherent channel between the two far-detuned qubits,thereby forming anΛ-type three-level system.We demonstrate that tuning the modulation amplitude enables the observation of spectral evolution from electromagnetically induced transparency(EIT)to Autler–Townes splitting(ATS).Furthermore,by exploiting the interplay between the non-local waveguide phase and system dissipation,the system achieves significant non-reciprocal microwave transmission and direction-selective photon emission.The scheme operates without external magnetic fields,offering an efficient pathway for realizing on-chip integrated quantum routers and isolators.
摘要Extending the operational wavelength range of integrated optical devices to cover the entire vis-ible spectrum holds significant importance,as it can enhance the detection accuracy and applicability of mini-aturized spectrometers,broaden the bandwidth of visible light communication,and enable biosensors to sim-ultaneously detect multiple biomolecules in complex samples.As the fundamental building block of integ-rated optical devices,waveguides have not yet been thoroughly investigated for full visible spectrum opera-tion.This work presents a waveguide design supporting the full visible spectrum(435−760 nm).Numerical simulations were employed to analyze the transmission characteristics of various waveguide structures,re-vealing that single-mode propagation cannot be achieved across the entire visible spectrum.Under mul-timode propagation conditions,key parameters such as propagation loss and mode distribution were system-atically examined to determine the optimal waveguide dimensions,bending radii,and waveguide spacings for low-loss transmission.For slab waveguides,a thickness≥1μm ensures polarization insensitivity.For strip waveguides with a thickness of 1μm,a width≥2μm significantly reduces scattering loss induced by side-wall roughness.For strip waveguides with a width of 1μm and thickness of 2μm,radiation loss becomes negligible when the bending radius≥10μm and waveguide spacing≥0.4μm,while maintaining effective isolation from adjacent waveguides.Additionally,the impact of fabrication tolerances on waveguide per-formance was evaluated.In contrast to previous studies primarily focusing on narrow spectral bands within the visible range,the proposed design enables full visible spectrum transmission in a single waveguide,thereby facilitating bandwidth expansion and performance enhancement for on-chip full visible spectrum devices.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFE0211800)。
摘要Owing to its compact footprint and superior filter properties,the Bragg grating filter is attractive for applications in optical communications.In this research,we conducted a detailed analysis of the influence of Bragg grating parameters on its functionality and experimentally validated our findings on a simple and low-cost polymer/silica hybrid waveguide platform.The best extinction ratio of 26.3 dB is obtained when the period is 6.63µm and the number of periods is 200.The full width at half maximum of the grating is 0.35 nm at 1544.74 nm.Tuning efficiency reaches 29.6 pm/mW owing to the high thermo-optical efficiency of the polymer.Finally,we measure the rise and fall times of the grating to be 280µs.The proposed grating shows great potential in flexible and reconfigurable optical networks.
基金supported by the Natural Science Foundation of Jilin Province of China(Grant No.20220101031JC)。
摘要We investigate the nonlinear Goos-Hanchen shift of a light beam reflected from a prism-coupled leaky waveguide containing a Kerr medium.As the incident power varies,the system can switch between two states,total internal reflection and frustrated total reflection,owing to the inherent positive feedback arising from the intensity-dependent guiding mode resonance.The reflectance exhibits optical bistability;meanwhile,the lateral shift of the reflected beam also shows hysteresis behavior.It is found that the transition between the two stable states is related to the excitation of a leaky mode in the waveguide,which results from the modulation of the electric field in the nonlinear substrate.We also analyze the effects of system parameters on the bistable Goos-Hanchen shift.The thresholds as well as the width of the hysteresis curve are sensitive to the thicknesses of the gap layer and the guiding layer,which determine the resonance angle.The bistable lateral displacement in the slab waveguide may have potential applications in optical switching,beam steering,etc.
基金supported by China Postdoctoral Foundation(2023M731680)the Youth Foundation of Jiangsu Province(BK20230919)。
摘要A millimeter-wave(mm-Wave)dual circularly polarized(CP)antenna in gap waveguide(GWG)technology with high port isolation is proposed in this paper.It is consisted of a simplified orthomode transducer(OMT)and an improved multi-section hexagonal waveguide CP horn antenna.The OMT is composed of two metal layers without the traditional septum or iris,which makes the structure simpler.The CP horn antenna can be easily integrated with the OMT without mode conversion.The principle analysis as well as the simulated and measured results of the proposed antenna are given in this paper.The simulated and measured results agree very well with each other.The port isolation of more than 27 dB over bandwidth of 26.5-31 GHz(|S11|<-15 dB)is achieved with relative bandwidth of 15.7%.The axial ratio(AR)lower than 2.5 dB for both left-hand and righthand CP(LHCP and RHCP)are achieved over the bandwidth.The proposed antenna is a candidate for mm-Wave satellite communications or beyond fifth-generation(5G)communications applications.
基金supported by the National Natural Science Foundation of China(No.52375414)the Science and Technology Commission of Shanghai Municipality(Nos.23ZR1404200 and 24511106602)。
摘要Commercial augmented reality(AR)glasses commonly employ geometrical or diffractive optical waveguides,which,despite their compact form factor,typically suffer from low optical efficiency.To achieve both thin form and high efficiency,for the first time,an AR optical waveguide based on a microprism is proposed.A deep-learning-assisted hardware±software cooptimization framework is introduced to expand the system's design freedom and enable end-to-end joint optimization between the microprism waveguide and the image preprocessing algorithm.Simulation results demonstrate that the proposed system achieves an overall thickness of only 8 mm,an optical efficiency of approximately 44.3%,high imaging quality,and a binocular field of view of 36°.This work provides a new pathway toward high-performance and ultra-thin AR display systems.
基金support from the European Union Horizon 2020 research and innovation program under grant agreement no.964588(X-PIC)from the European Research Council MSCA-ITN SMART-X(Grant No.860553)from the European Union’s NextGenerationEU Programme with the I-PHOQS Infrastructure[IR0000016,ID D2B8D520,CUP B53C22001750006]“Integrated infrastructure initiative in Photonic and Quantum Sciences,”under National Recovery and Resilience Plan(NRRP),Mission 4,Component 2,Investment 1.1,Call for tender No.1409 published on 14.9.2022 by MUR,from the European Union–Next Generation EU–Project P20224AWLB“HAPPY”–CUP B53D23025210001-Grant Assignment Decree No.1386 adopted on 01/09/2023 by MUR,under the NRRP,Mission 4,Component 2,Investment 1.1,Call for Tender No.104 published on February 02,2022,by MUR,from the European Union—NextGenerationEU—Project No.20224KAC28“CHANGE”—CUP B53D23013410006—Grant Assignment Decree No.958 adopted on June 30,2023,by MUR,and from the bilateral agreement between CNR and JSI(Slovenia).
摘要Leveraging the natural axial confinement of coherent extreme ultraviolet(EUV)light generated via the high-order harmonic generation process,we demonstrate the spatial separation of EUV and the driving infrared(IR)beams through hollow-core microchannels embedded in a laser machine glass device.This structure enables broadband EUV transmission while attenuating the collinear IR by 2 orders of magnitude.In addition,we explore the potential of integrated photonic architectures based on EUV-guiding hollow structures,laying the foundation for a new class of compact,palm-top devices for EUV and soft X-ray 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)。
摘要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supported in part by the Natural Science Foundation of Tianjin(No.19JCYBJC16100)the Tianjin Innovation and Entrepreneurship Training Program(No.202210060027)。
摘要A triple-band miniaturized end-fire antenna based on the odd modes of spoof surface plasmonic polariton(SSPP)waveguide resonator is proposed in this paper.To meet the ever increasing demand for more communication channels and less antenna sizes,multi-band antennas are currently under intensive investigation.By a novel feeding method,three odd modes are excited on an SSPP waveguide resonator,which performs as an end-fire antenna operating at three bands,7.15-7.26 GHz,11.6-12.2 GHz and 13.5-13.64 GHz.It exhibits reasonably high and stable maximum gains of 5.26 dBi,7.97 dBi and 10.1 dBi and maximum efficiencies of 64%,92%and 98%at the three bands,respectively.Moreover,in the second band,the main beam angle shows a frequency dependence with a total scanning angle of 19°.The miniaturized triple-band antenna has a great potential in wireless communication systems,satellite communication and radar systems.
摘要A plasmonics waveguide structure that consist of a non-through metal–insulator–metal(MIM)waveguide coupled with a D-shaped cavity was designed.And the transmission properties,magnetic field distribution,and refractive index sensing functionality were simulated using the finite element method(FEM).A multi-Fano resonance phenomenon was clearly observable in the transmission spectra.The Fano resonances observed in the proposed structure arise from the interaction between the discrete states of the Dshaped resonant cavity and the continuum state of the non-through MIM waveguide.The influence of structural parameters on Fano resonance modulation was investigated through systematic parameter adjustments.Additionally,the refractive index sensing properties,based on the Fano resonance,were investigated by varying the refractive index of the MIM waveguide's insulator layer.A maximum sensitivity and FOM of 1155 RIUm and 40 were achieved,respectively.This research opens up new possibilities for designing and exploring high-sensitivity photonic devices,micro-sensors,and innovative on-chip sensing architectures for future applications.
基金funding support from the National Natural Science Foundation of China(Grant No.52404224)Beijing Natural Science Foundation(Grant No.8244051)the fellowship of China National Postdoctoral Program for Innovative Talents(Grant No.BX20230175).
摘要Compared to existing deformation monitoring methods,landslide early warning can be achieved by detecting precursor signals of slope instability through acoustic emission(AE).Acquisition of AE signals generated by active waveguide facilitates monitoring the development of shear surface and provides a foundation for quantifying landslide movement.Backfill particles are the dominant AE sources in active waveguides,typically chosen from materials such as gravels or sands.However,the influence of particle sizes and gradings has not been clarified in existing laboratory models or field monitoring.This research introduces a direct shear test for active waveguide,where spherical glass beads are employed to precisely regulate the size and grading of backfill particles.A programmable logic controller maintains a constant shearing speed and equivalent total deformation.Through a comprehensive analysis of AE,deformation,and mechanical measurements,this study evaluates the impact of particle size and grading on monitoring capabilities.The findings suggest that the AE mechanism in glass beads is attributed to particle collision and dislocation,leading to AE events characterized by low amplitude and energy levels.The percentage of high-amplitude AE events rises steadily with the progression of shearing.The correlation between shear force,cumulative ring down count(RDC)of AE,and deformation conforms to a power function,with the exponent relying on particle size,grading,and shearing speed.Notably,the combination of small particles and low shearing speeds can yield the maximum cumulative RDC,while selecting particles with uneven grading will significantly enhance the intensity of AE signals from active waveguide.
摘要Ferrimagnetic materials exhibiting remanence can be used to achieve unidirectional electromagnetic-field propagation in the form of magnetoplasmons(MPs)in the subwavelength regime.This study investigates the MP properties and various guiding modes in a hollow cylindrical waveguide made of materials that exhibit remanence.Pattern analysis and numerical simulations are used to demonstrate that dispersion relationships and electromagnetic-field distribution are strongly affected by the operating frequency and physical dimensions of the structure.In addition,the existence of two different guiding modes is proved,namely regular and surface-wave modes.By adjusting the operating frequency and reducing the diameter of the hollow cylinder,the regular mode can be suppressed so as to only retain the surface-wave mode,which enables unidirectional MP propagation in the cylindrical waveguide.Moreover,the unidirectional surface-wave mode is robust to backscattering due to surface roughness and defects,which makes it very useful for application in field-enhancement devices.
基金supported by the Postgraduate Research and Innovation Program of Jiangsu Province,China(Grant No.KYCX241133)the National Natural Science Foundation of China(Grant No.11405041)+1 种基金the Key Research and Development Program of Jiangxi Province,China(Grant No.20223BBE51020)the Opening Fund of Key Laboratory of Rare Earths(Chinese Academy of Sciences).
摘要Integrating the magneto-optical effect into a waveguide-based photonic device becomes more and more interesting.In the work,the planar optical waveguide firstly was prepared in a terbium gallium garnet crystal(TGG)via the proton implantation with the energy of 4×10-1MeV and the fluence of 6×108ions/μm2.Subsequently,a femtosecond laser with a central wavelength of 800 nm and a power of 3 mW was used to ablate the surface of the planar waveguide,forming the ridge optical waveguide.The dark-mode curve of the planar waveguide was measured by a prism coupling technique.The top-view morphology of the ridge waveguide was observed via a Nikon microscope.The mode field distributions of the planar and ridge waveguides were obtained by an end-face coupling system,and the propagation losses of the two waveguides were measured to be 2.26 dB/cm and 2.58 dB/cm,respectively.The Verdet constants were measured to be-72.7°/T·cm for the TGG substrate and-60.7°/T·cm for the ridge waveguide.The TGG waveguides have a potential in the fabrication of magneto-optical waveguide devices.
基金Supported by the National Natural Science Foundation of China(62105039)。
摘要In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particularly pronounced with an increase in ridge width,resulting in multimode problems.To tackle this,an innovative multi ridge waveguide structure based on the principle of supersymmetry(SUSY)was proposed.This structure comprises a wider main waveguide in the center and two narrower auxiliary waveguides on either side.The high-order modes of the main waveguide are coupled with the modes of the auxiliary waveguides through mode-matching design,and the optical loss of the auxiliary waveguides suppresses these modes,thereby achieving fundamental mode lasing of the wider main waveguide.This paper employs the finite difference eigenmode(FDE)method to perform detailed structural modeling and simulation optimization of the 4.6μm wavelength quantum cascade laser,successfully achieving a single transverse mode QCL with a ridge width of 10μm.In comparison to the traditional single-mode QCL(with a ridge width of about 5μm),the MRW structure has the potential to increase the gain area of the laser by 100%.This offers a novel design concept and methodology for enhancing the single-mode luminous power of mid-infrared quantum cascade lasers,which is of considerable significance.
基金supported by the National Natural Science Foundation of China(Grant Nos.12475010 and 119075023)the Major Project of the Natural Science Foundation of Anhui Provincial Department of Education(Grant No.2022AH040053)the Key Natural Scientific Research Projects of Universities in Anhui Province(Grant Nos.2023AH051078 and 2023AH051125)。
摘要The phase-controlled single-photon transport properties of a giant atom coupled to a one-dimensional waveguide are investigated.The coupling between the giant atom and the waveguide is modeled as a multi-point interaction.The coupling strengths between the giant atom and the waveguide are represented as complex numbers with associated phases.Analytical expressions for the scattering amplitudes are obtained using the real-space Hamiltonian method.The results show that the characteristics of the scattering spectra,including the positions of peaks(or dips)and the full width at half maximum,can be tuned by adjusting the phase difference between the coupling strengths.Further calculations reveal that the scattering spectra can be either super-broadened or sub-broadened.The conditions for achieving perfect nonreciprocal single-photon transport in the Markovian regime are also discussed.Moreover,we demonstrate the control of single-photon transport through phase differences in the non-Markovian regime.Our results may find applications in the design of quantum devices operating at the single-photon level,based on waveguide quantum electrodynamics.
基金supported by the National Natural Science Foundation of China(Grant Nos.62175050 and U2341245)the Fundamental Research Funds for the Central Universities(Grant No.HIT.OCEF.2024054).
摘要Diffractive optical neural networks(DONNs)have exhibited the advantages of parallelization,high speed,and low consumption.However,the existing DONNs based on free-space diffractive optical elements are bulky and unsteady.In this study,we propose a planar-waveguide integrated diffractive neural network chip architecture.The three diffractive layers are engraved on the same side of a quartz wafer.The three-layer chip is designed with 32-mm3 processing space and enables a computing speed of 3.1×109 Tera operations per second.The results show that the proposed chip achieves 73.4%experimental accuracy for the Modified National Institute of Standards and Technology database while showing the system’s robustness in a cycle test.The consistency of experiments is 88.6%,and the arithmetic mean standard deviation of the results is~4.7%.The proposed chip architecture can potentially revolutionize high-resolution optical processing tasks with high robustness.