Precise control over organic reaction dynamic requires in-situ insight into temperature and concentration variations.However,conventional detection strategies,often relying on off-line or decoupled methods,suffer from...Precise control over organic reaction dynamic requires in-situ insight into temperature and concentration variations.However,conventional detection strategies,often relying on off-line or decoupled methods,suffer from delayed responses and poor temporal synchronization.Herein,we propose a bifunctional single-fiber sensor based on Ge5As25Se30Te40 chalcogenide glass,which seamlessly integrates fiber evanescent wave spectroscopy for chemical fingerprinting identification with a thermoresistive effect for thermal sensing.It exhibits exceptional performance with a rapid temperature response(~2.6 s)and a high temperature sensitivity(jTCRj~4.07%K-1).Validated through the in-situ monitoring of ethyl butyrate synthesis,the single-fiber sensor effectively tracked reaction evolution and thermal distinctness,providing reliable guidance for process optimization and control.With its label-free detection,structural simplicity,and high sensitivity,this proposed strategy represents a robust process analytical technology tool for monitoring complex organic reactions.展开更多
In this work,we experimentally demonstrate a high-power supercontinuum(SC)that covers from visible to mid-infrared(MIR)in a GeO2-core fiber(GCF)bundle via incoherent beam combination.In the experiment,the SC generatio...In this work,we experimentally demonstrate a high-power supercontinuum(SC)that covers from visible to mid-infrared(MIR)in a GeO2-core fiber(GCF)bundle via incoherent beam combination.In the experiment,the SC generation in a single GCF was initially explored,and an SC spanning from visible to MIR regions was obtained,with average power of less than 10 W.To increase the output power,we fabricated a 3×1 high-power GCF-based tapered fiber bundle,incoherently combining three channels of the previously mentioned replicas.This yielded a broadband SC spectrum with a maximum average power of 23.1 W and a spectral bandwidth covering 0.73–3.1μm.The obtained spectrum power fluctuation was measured over 1 hour,showing a root mean square value of 0.7%.To the best of our knowledge,this represents the highest power SC from visible to MIR regions obtained in GCFs pumped by 1.55μm high-power pulses.展开更多
A series of alkali halide doped chalcohalide glasses (100-x)(0.9GeS2-0.1Sb2S3)-xCsCl (x=5, 10, 15 and 20 mole fraction) were prepared. The absorption spectra and Raman scatting spectra of these glasses were meas...A series of alkali halide doped chalcohalide glasses (100-x)(0.9GeS2-0.1Sb2S3)-xCsCl (x=5, 10, 15 and 20 mole fraction) were prepared. The absorption spectra and Raman scatting spectra of these glasses were measured. The optical band gaps Eopt were obtained from ultraviolet absorption edges. Z-scan technique was utilized to investigate the third-order nonlinear optical properties of GeS2-Sb2S3-CsCl glasses. The value of Eopt increases and the third-order optical nonlinearity decreases with increasing CsCl content. Decreasing lone-pair electron and broadening the band-gap will provide less transition paths for nonlinear process, which play a key role in ultrafast third-order nonlinear optical responses of these chalcohalide glasses.展开更多
Based on material design idea,we employ a co-precipitation strategy to obtain sinterable Ho2Zr2O7 flu-orite particles,successfully leading to novel transparent Ho2Zr2O7 ceramics with good optical/mag...Based on material design idea,we employ a co-precipitation strategy to obtain sinterable Ho2Zr2O7 flu-orite particles,successfully leading to novel transparent Ho2Zr2O7 ceramics with good optical/magneto-optical properties.The resulting precipitation precursor is identified to be hydrated basic carbonate upon calcination at the optimum temperature of 1250℃into near-spherical Ho2Zr2O7 nanopowder with an average size of~64 nm and unimodal narrow size distribution.The crystal intrinsic oxygen defect in fluorite ceramic generally exists in the form of F+center.The best bulk specimen achieved in this work exhibits a high refractive index of~2.1 and a high transparency of~74.4%at 1000 nm comparable with the corresponding defect-free single crystal(~76.4%in theory).In the Ho2Zr2O7 structure system,the elec-tronic polarizability of O2-anion generally remains constant around 2.2?3 in the visible region and the corresponding optical basicity is approximately 0.9.The developed magneto-optical transparent Ho2Zr2O7 ceramic has Verdet constants of-180±3,-157±5,-87±2,-54±2,and-43±2 rad T-1 m-1 at 515,635,780,980,and 1064 nm,respectively,which are roughly 1.2-fold higher than the commercial TGG crystal.展开更多
We report the fabrication and characterization of germanium gallium antimony sulfide(Ge–Ga–Sb–S or 2 S2 G, doped with Tm^(3+)ions) microsphere lasers operating at ~1.9-μm spectral band. Compared to the chalc...We report the fabrication and characterization of germanium gallium antimony sulfide(Ge–Ga–Sb–S or 2 S2 G, doped with Tm^(3+)ions) microsphere lasers operating at ~1.9-μm spectral band. Compared to the chalcogenide glasses that are used in previous microsphere lasers, this 2 S2 G glass has a lower transition temperature and a higher characteristic temperature. This implies that 2 S2 G microspheres can be fabricated at lower temperatures and the crystallization problem in the sphere-forming process can be alleviated. We show that hundreds of high-quality microspheres(quality factors higher than 105) of various diameters can be produced simultaneously via a droplet sphere-forming method. Microspheres are coupled with silica fiber tapers for optical characterizations. We demonstrate that Whispering Gallery mode(WGM)patterns in the 1.7–2.0 μm band can be conveniently obtained and that once the pump power exceeds a threshold, single-and multi-mode microsphere lasers can be generated. For a typical microsphere whose diameter is 258.64 μm, we demonstrate its laser threshold is 0.383 mW, the laser wavelength is 1907.38 nm, and the thermal sensitivity of the microsphere laser is29.56 pm/?C.展开更多
The amorphous phase-change materials with spontaneous structural relaxation leads to the resistance drift with the time for phase-change neuron synaptic devices. Here, we modify the phase change properties of the conv...The amorphous phase-change materials with spontaneous structural relaxation leads to the resistance drift with the time for phase-change neuron synaptic devices. Here, we modify the phase change properties of the conventional Ge_2Sb_2Te_5(GST) material by introducing an SnS phase. It is found that the resistance drift coefficient of SnS-doped GST was decreased from 0.06 to 0.01. It can be proposed that the origin originates from the precipitation of GST nanocrystals accompanied by the precipitation of SnS crystals compared to single-phase GST compound systems. We also found that the decrease in resistance drift can be attributed to the narrowed bandgap from 0.65 to 0.43 eV after SnS-doping. Thus, this study reveals the quantitative relationship between the resistance drift and the band gap and proposes a new idea for alleviating the resistance drift by composition optimization, which is of great significance for finding a promising phase change material.展开更多
Achieving low-loss optical interfaces between high-refractive-index(n>2)components is critical for mid-infrared photonic systems,yet hindered by the trade-off between refractive index matching,IR transparency and t...Achieving low-loss optical interfaces between high-refractive-index(n>2)components is critical for mid-infrared photonic systems,yet hindered by the trade-off between refractive index matching,IR transparency and thermal stability.Here,we introduce a groundbreaking solution—bonding the optical lenses and fibers with a liquid-like chalcogenide glass,which possesses an ultra-low glass transition temperature below room temperature,high refractive index and exceptional mid-infrared transparency.The basic performances of the liquid glass are characterized and proved by detailed viscosity distribution,mechanical shear and bonding tensile strength measurements.Most of all,the optical transmission and laser delivery of these bonded chalcogenide glass fiber devices demonstrate a significant improvement,with transmission efficiency increasing from 36%to 91%,and laser power delivery from several hundred mW rising to 14.5W at a wavelength near 4μm.Additionally,the system demonstrates long-term stability,maintaining performance over at least 3 months and more than 206 heating-cooling cycles when utilizing this liquid-like glass adhesive.This research not only addresses the challenge of bonding midinfrared optical components but also holds immense promise for advancing integrated mid-infrared optics applications,including spectroscopy,sensing,and imaging.展开更多
A novel method for designing chalcogenide long-period fiber grating(LPFG) sensors based on the dual-peak resonance effect of the LPFG near the phase matching turning point(PMTP) is presented. Refractive index sensing ...A novel method for designing chalcogenide long-period fiber grating(LPFG) sensors based on the dual-peak resonance effect of the LPFG near the phase matching turning point(PMTP) is presented. Refractive index sensing in a high-refractive-index chalcogenide fiber is achieved with a coated thinly clad film. The dual-peak resonant characteristics near the PMTP and the refractive index sensing properties of the LPFG are analyzed first by the phase-matching condition of the LPFG. The effects of film parameters and cladding radius on the sensitivity of refractive index sensing are further discussed. The sensor is optimized by selecting the appropriate film parameters and cladding radius. Simulation results show that the ambient refractive index sensitivity of a dual-peak coated thinly clad chalcogenide LPFG at the PMTP can be 2400 nm/RIU, which is significantly higher than that of non-optimized gratings. It has great application potential in the field of chemical sensing and biosensors.展开更多
Structured light,with its multidimensional control over amplitude,phase,space and frequency,is a key enabler for advanced technologies such as high-capacity communications,quantum information,and super-resolution imag...Structured light,with its multidimensional control over amplitude,phase,space and frequency,is a key enabler for advanced technologies such as high-capacity communications,quantum information,and super-resolution imaging.Here,we propose a unified inverse-design methodology for arbitrary on-chip vectorial structured-light.Inspired by quantum-state representations,we describe complex vector fields as finite-dimensional vectors in a Hilbert space and introduce a transmission-matrix formalism that links input waveguide modes to target topological edge states.By combining this mapping with adjoint-based topology optimization,we obtain the permittivity distribution within a compact design window that realizes the desired vector transformation while preserving topological transport.We experimentally demonstrate two representative domain-wall configurations on a valley photonic crystal(VPC)platform,termed Type-I and Type-II topological couplers,which efficiently couple the fundamental TE0 mode into valley pseudospin edge states.Simulations of the ideally designed device show insertion losses of 0.04 dB and 0.09 dB at 1550 nm with 3-dB bandwidths of 132 nm and 65 nm,respectively.Experimentally,the fabricated device,which was designed accounting for fabrication tolerances,maintains a broadband low-loss performance,with measured losses of60 nm and<0.8 dB at 1550 nm with 3-dB bandwidth over 87 nm.Mirror-symmetric designs further validate selective excitation of orthogonal pseudospin states.Our results establish this inverse-design methodology as a powerful tool for strictly controlling on-chip vectorial light,paving the way toward compact,broadband,and multifunctional photonic integrated circuits for optical computing,communications,and beyond.展开更多
Improvements to body-surface physiological monitoring ability including real-time,accuracy and integration,are essential to meet the expansive demands for personal healthcare.As part of this,simultaneous monitoring of...Improvements to body-surface physiological monitoring ability including real-time,accuracy and integration,are essential to meet the expansive demands for personal healthcare.As part of this,simultaneous monitoring of sweat metabolites and body temperature offers an exciting path to maximizing diagnostic precision and minimizing morbidity rates.Herein,we report a high-performance biomarker-temperature sensor made of a single As3Se5Te2chalcogenide glass fiber to monitor physiology evolution on body-surface.The sensor integrates efficient thermal resistance and fiber evanescent wave effects,permitting the independent sensing of temperature and biomarkers with an ultrahigh temperature coefficient of resistance(−5.84%K–1),rapid temperature response(0.3 s)and excellent IR sensing sensitivity.Moreover,by attaching a fiber to the wrist,we demonstrate simultaneous observation of both sweat metabolite(urea and lactate)and temperature changes during exercise.This illuminating sensing method will provide crucial capabilities in physiological monitoring and pave the way for advanced personalized diagnostic.展开更多
In this paper,a graphene oxide(GO)composite film-coated humidity sensor is proposed based on the hollow core fiber(HCF).A segment of the HCF is spliced between two segments of the single-mode fiber(SMF).The relative h...In this paper,a graphene oxide(GO)composite film-coated humidity sensor is proposed based on the hollow core fiber(HCF).A segment of the HCF is spliced between two segments of the single-mode fiber(SMF).The relative humidity(RH)sensing characteristics of the sensor are experimentally investigated by observing the intensity shift of resonant dips in the transmission spectrum,which shows the GO composite film-coated HCF has the good stability in the measurement of humidity.The maximum humidity sensitivity of 0.12 dB/%RH is obtained in the RH range of 30%–78%.The proposed sensor has the advantages of the simple structure,easy fabrication,good stability,and high performance,which can be applied to marine climate detection,tunnel air humidity detection,agricultural testing,and other fields.展开更多
Chalcogenide(ChG)glasses have the characteristics of a wide transparency window(over 20μm)and high optical nonlinearity(up to 103 times greater than that of silica glasses),exhibiting great advantages over silica and...Chalcogenide(ChG)glasses have the characteristics of a wide transparency window(over 20μm)and high optical nonlinearity(up to 103 times greater than that of silica glasses),exhibiting great advantages over silica and other soft glasses in optical property at mid-infrared(MIR)wavelength range.These make them excellent candidates for MIR supercontinuum(SC)generation.Over the past decades,great progress has been made in MIR SC generation based on ChG fibers in terms of spectral extension and output power improvement.In this paper,we introduce briefly the properties of ChG glasses and fibers including transmission,nonlinearity,and dispersion,etc.Recent progress in MIR SC generation based on ChG fibers is reviewed from the perspective of pump schemes.We also present novel ChG fibers such as As-free,Te-based,and chalcohalide fibers,which have been explored and employed as nonlinear fibers to achieve broadband SC generation.Moreover,the potential applications of MIR SC sources based on ChG fibers are discussed.展开更多
We report on the investigation of intermode beating mode-locked(IBML)pulse generation in a simple all-fiber Tm^3+-doped double clad fiber laser(TDFL).This IBML TDFL is implemented by matching longitudinal-mode frequen...We report on the investigation of intermode beating mode-locked(IBML)pulse generation in a simple all-fiber Tm^3+-doped double clad fiber laser(TDFL).This IBML TDFL is implemented by matching longitudinal-mode frequency between 793 nm laser and TDFL without extra mode locker.The central wavelength of 1983 nm,the fundamental pulse frequency of 9.6 MHz and the signal-to-noise ratio(SNR)of>50 dB are achieved in this IBML TDFL.With laser cavity optimization,the IBML TDFL can finally generate an average output power of 1.03 W with corresponding pulse energy of 107 nJ.These results can provide an easily accessible way to develop compact large-energy,highpower TDFLs.展开更多
A flexible-grid 1×(2×3)mode-and wavelength-selective switch which comprises counter-tapered couplers and silicon microring resonators has been proposed,optimized,and demonstrated experimentally in this work....A flexible-grid 1×(2×3)mode-and wavelength-selective switch which comprises counter-tapered couplers and silicon microring resonators has been proposed,optimized,and demonstrated experimentally in this work.By carefully thermally tuning phase shifters and silicon microring resonators,mode and wavelength signals can be independently and flexibly conveyed to any one of the output ports,and different bandwidths can be generated as desired.The particle swarm optimization algorithm and finite difference time-domain method are employed to optimize structural parameters of the twomode(de)multiplexer and crossing waveguide.The bandwidth-tunable wavelength-selective optical router composed of12 microring resonators is studied by taking advantage of the transfer matrix method.Measurement results show that,for the fabricated module,cross talk less than-10.18 dB,an extinction ratio larger than 17.41 d B,an in-band ripple lower than0.79 dB,and a 3-dB bandwidth changing from 0.38 to 1.05 nm are obtained,as the wavelength-channel spacing is 0.40 nm.The corresponding response time is measured to be 13.64μs.展开更多
A polarization-insensitive mode-order converting power splitter using a pixelated region is presented and investigated in this paper.As TE0and TM0modes are injected into the input port,they are converted into TE...A polarization-insensitive mode-order converting power splitter using a pixelated region is presented and investigated in this paper.As TE0and TM0modes are injected into the input port,they are converted into TE1and TM1modes,which evenly come out from the two output ports.The finite-difference time-domain method and direct-binary-search optimization algorithm are utilized to optimize structural parameters of the pixelated region to attain small insertion loss,low crosstalk,wide bandwidth,excellent power uniformity,polarization-insensitive property,and compact size.Experimental results reveal that the insertion loss,crosstalk,and power uniformity of the fabricated device at 1550 nm are 0.57,-19.67,and 0.094 d B in the case of TE polarization,while in the TM polarization,the relevant insertion loss,crosstalk,and power uniformity are 0.57,-19.40,and 0.11 d B.Within a wavelength range from 1520 to 1600 nm,for the fabricated device working at TE polarization,the insertion loss,crosstalk,and power uniformity are lower than 1.39,-17.64,and 0.14 dB.In the case of TM polarization,we achieved an insertion loss,crosstalk,and power uniformity less than 1.23,-17.62,and 0.14 dB.展开更多
基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2025C01166)Natural Science Foundation of Zhejiang Province(LY23F050006,LY23E020006)+3 种基金Natural Science Foundation of Ningbo Municipality(2024J460,2024J225)National Key Research and Development Program of China(2024YFB4608100)Fundamental Research Funds for the Provincial Universities of ZhejiangK.C.Wong Magna Fund in Ningbo University。
摘要Precise control over organic reaction dynamic requires in-situ insight into temperature and concentration variations.However,conventional detection strategies,often relying on off-line or decoupled methods,suffer from delayed responses and poor temporal synchronization.Herein,we propose a bifunctional single-fiber sensor based on Ge5As25Se30Te40 chalcogenide glass,which seamlessly integrates fiber evanescent wave spectroscopy for chemical fingerprinting identification with a thermoresistive effect for thermal sensing.It exhibits exceptional performance with a rapid temperature response(~2.6 s)and a high temperature sensitivity(jTCRj~4.07%K-1).Validated through the in-situ monitoring of ethyl butyrate synthesis,the single-fiber sensor effectively tracked reaction evolution and thermal distinctness,providing reliable guidance for process optimization and control.With its label-free detection,structural simplicity,and high sensitivity,this proposed strategy represents a robust process analytical technology tool for monitoring complex organic reactions.
基金supported by the National Natural Science Foundation of China(Grant Nos.62090065,62205015 and 62275015)the Natural Science Foundation of Ningbo(Grant No.2022J078)the Technology Innovation Center of Infrared Remote Sensing Metrology Technology,State Administration for Market Regulation(Grant No.AKYKF2425)。
摘要In this work,we experimentally demonstrate a high-power supercontinuum(SC)that covers from visible to mid-infrared(MIR)in a GeO2-core fiber(GCF)bundle via incoherent beam combination.In the experiment,the SC generation in a single GCF was initially explored,and an SC spanning from visible to MIR regions was obtained,with average power of less than 10 W.To increase the output power,we fabricated a 3×1 high-power GCF-based tapered fiber bundle,incoherently combining three channels of the previously mentioned replicas.This yielded a broadband SC spectrum with a maximum average power of 23.1 W and a spectral bandwidth covering 0.73–3.1μm.The obtained spectrum power fluctuation was measured over 1 hour,showing a root mean square value of 0.7%.To the best of our knowledge,this represents the highest power SC from visible to MIR regions obtained in GCFs pumped by 1.55μm high-power pulses.
基金supported by the National Ba-sic Research Program of China ("973 Project", (No2006CB708607)the Science and Technology Department of Zhejiang Province, China (No 2006C11127)+1 种基金the Science and Technology Foundation of Ningbo, China (No2006B100068)the Natural Science Foundation of Ningbo, China (Nos 2006A610056, 2007A610004)
摘要A series of alkali halide doped chalcohalide glasses (100-x)(0.9GeS2-0.1Sb2S3)-xCsCl (x=5, 10, 15 and 20 mole fraction) were prepared. The absorption spectra and Raman scatting spectra of these glasses were measured. The optical band gaps Eopt were obtained from ultraviolet absorption edges. Z-scan technique was utilized to investigate the third-order nonlinear optical properties of GeS2-Sb2S3-CsCl glasses. The value of Eopt increases and the third-order optical nonlinearity decreases with increasing CsCl content. Decreasing lone-pair electron and broadening the band-gap will provide less transition paths for nonlinear process, which play a key role in ultrafast third-order nonlinear optical responses of these chalcohalide glasses.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (Grant No.LY23F050007)the Department of Education of Zhejiang Province (No.Y202146207).
摘要Based on material design idea,we employ a co-precipitation strategy to obtain sinterable Ho2Zr2O7 flu-orite particles,successfully leading to novel transparent Ho2Zr2O7 ceramics with good optical/magneto-optical properties.The resulting precipitation precursor is identified to be hydrated basic carbonate upon calcination at the optimum temperature of 1250℃into near-spherical Ho2Zr2O7 nanopowder with an average size of~64 nm and unimodal narrow size distribution.The crystal intrinsic oxygen defect in fluorite ceramic generally exists in the form of F+center.The best bulk specimen achieved in this work exhibits a high refractive index of~2.1 and a high transparency of~74.4%at 1000 nm comparable with the corresponding defect-free single crystal(~76.4%in theory).In the Ho2Zr2O7 structure system,the elec-tronic polarizability of O2-anion generally remains constant around 2.2?3 in the visible region and the corresponding optical basicity is approximately 0.9.The developed magneto-optical transparent Ho2Zr2O7 ceramic has Verdet constants of-180±3,-157±5,-87±2,-54±2,and-43±2 rad T-1 m-1 at 515,635,780,980,and 1064 nm,respectively,which are roughly 1.2-fold higher than the commercial TGG crystal.
基金Project supported by the National Natural Science Foundation of China(Grant No.61605094)the Key Program of National Natural Science Foundation of China(Grant No.61435009)+1 种基金the Natural Science Foundation of Zhejiang Province,China(Grant No.LQ15F050002)K.C.Wong Magna Fund in Ningbo University,China
摘要We report the fabrication and characterization of germanium gallium antimony sulfide(Ge–Ga–Sb–S or 2 S2 G, doped with Tm^(3+)ions) microsphere lasers operating at ~1.9-μm spectral band. Compared to the chalcogenide glasses that are used in previous microsphere lasers, this 2 S2 G glass has a lower transition temperature and a higher characteristic temperature. This implies that 2 S2 G microspheres can be fabricated at lower temperatures and the crystallization problem in the sphere-forming process can be alleviated. We show that hundreds of high-quality microspheres(quality factors higher than 105) of various diameters can be produced simultaneously via a droplet sphere-forming method. Microspheres are coupled with silica fiber tapers for optical characterizations. We demonstrate that Whispering Gallery mode(WGM)patterns in the 1.7–2.0 μm band can be conveniently obtained and that once the pump power exceeds a threshold, single-and multi-mode microsphere lasers can be generated. For a typical microsphere whose diameter is 258.64 μm, we demonstrate its laser threshold is 0.383 mW, the laser wavelength is 1907.38 nm, and the thermal sensitivity of the microsphere laser is29.56 pm/?C.
基金financially supported by the National Natural Science Foundation of China(Grant No.62074089)the Natural Science Foundation of Ningbo City,China(Grant No.2022J072)+1 种基金the Youth Science and Technology Innovation Leading Talent Project of Ningbo City,China(Grant No.2023QL005)sponsored by the K.C.Wong Magna Fund in Ningbo University。
摘要The amorphous phase-change materials with spontaneous structural relaxation leads to the resistance drift with the time for phase-change neuron synaptic devices. Here, we modify the phase change properties of the conventional Ge_2Sb_2Te_5(GST) material by introducing an SnS phase. It is found that the resistance drift coefficient of SnS-doped GST was decreased from 0.06 to 0.01. It can be proposed that the origin originates from the precipitation of GST nanocrystals accompanied by the precipitation of SnS crystals compared to single-phase GST compound systems. We also found that the decrease in resistance drift can be attributed to the narrowed bandgap from 0.65 to 0.43 eV after SnS-doping. Thus, this study reveals the quantitative relationship between the resistance drift and the band gap and proposes a new idea for alleviating the resistance drift by composition optimization, which is of great significance for finding a promising phase change material.
基金supported by the National Natural Science Foundation of China U22A2085 and 62205163,Natural Science Foundation of Ningbo 2024J229.
摘要Achieving low-loss optical interfaces between high-refractive-index(n>2)components is critical for mid-infrared photonic systems,yet hindered by the trade-off between refractive index matching,IR transparency and thermal stability.Here,we introduce a groundbreaking solution—bonding the optical lenses and fibers with a liquid-like chalcogenide glass,which possesses an ultra-low glass transition temperature below room temperature,high refractive index and exceptional mid-infrared transparency.The basic performances of the liquid glass are characterized and proved by detailed viscosity distribution,mechanical shear and bonding tensile strength measurements.Most of all,the optical transmission and laser delivery of these bonded chalcogenide glass fiber devices demonstrate a significant improvement,with transmission efficiency increasing from 36%to 91%,and laser power delivery from several hundred mW rising to 14.5W at a wavelength near 4μm.Additionally,the system demonstrates long-term stability,maintaining performance over at least 3 months and more than 206 heating-cooling cycles when utilizing this liquid-like glass adhesive.This research not only addresses the challenge of bonding midinfrared optical components but also holds immense promise for advancing integrated mid-infrared optics applications,including spectroscopy,sensing,and imaging.
基金Project supported by the Natural Science Foundation of China (Grant Nos.62075107,61935006,62090064,and62090065)K.C.Wong Magna Fund in Ningbo University。
摘要A novel method for designing chalcogenide long-period fiber grating(LPFG) sensors based on the dual-peak resonance effect of the LPFG near the phase matching turning point(PMTP) is presented. Refractive index sensing in a high-refractive-index chalcogenide fiber is achieved with a coated thinly clad film. The dual-peak resonant characteristics near the PMTP and the refractive index sensing properties of the LPFG are analyzed first by the phase-matching condition of the LPFG. The effects of film parameters and cladding radius on the sensitivity of refractive index sensing are further discussed. The sensor is optimized by selecting the appropriate film parameters and cladding radius. Simulation results show that the ambient refractive index sensitivity of a dual-peak coated thinly clad chalcogenide LPFG at the PMTP can be 2400 nm/RIU, which is significantly higher than that of non-optimized gratings. It has great application potential in the field of chemical sensing and biosensors.
基金supported by the National Key Research and Development Program of China(No.2024YFB2808700)“Pioneer”R&D Program of Zhejiang(No.2025C01002)the Key Project of Westlake Institute for Optoelectronics(No.2024GD002)。
摘要Structured light,with its multidimensional control over amplitude,phase,space and frequency,is a key enabler for advanced technologies such as high-capacity communications,quantum information,and super-resolution imaging.Here,we propose a unified inverse-design methodology for arbitrary on-chip vectorial structured-light.Inspired by quantum-state representations,we describe complex vector fields as finite-dimensional vectors in a Hilbert space and introduce a transmission-matrix formalism that links input waveguide modes to target topological edge states.By combining this mapping with adjoint-based topology optimization,we obtain the permittivity distribution within a compact design window that realizes the desired vector transformation while preserving topological transport.We experimentally demonstrate two representative domain-wall configurations on a valley photonic crystal(VPC)platform,termed Type-I and Type-II topological couplers,which efficiently couple the fundamental TE0 mode into valley pseudospin edge states.Simulations of the ideally designed device show insertion losses of 0.04 dB and 0.09 dB at 1550 nm with 3-dB bandwidths of 132 nm and 65 nm,respectively.Experimentally,the fabricated device,which was designed accounting for fabrication tolerances,maintains a broadband low-loss performance,with measured losses of60 nm and<0.8 dB at 1550 nm with 3-dB bandwidth over 87 nm.Mirror-symmetric designs further validate selective excitation of orthogonal pseudospin states.Our results establish this inverse-design methodology as a powerful tool for strictly controlling on-chip vectorial light,paving the way toward compact,broadband,and multifunctional photonic integrated circuits for optical computing,communications,and beyond.
基金supported by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(Grant No.2025C01166)National Natural Science Foundation of China(Grant Nos.62105168,62122039)+2 种基金Zhejiang Provincial Natural Science Foundation of China(Grant No.LY23F050006)Ningbo Natural Science Foundation(Grant No.2024J460)sponsored by K.C.Wong Magna Fund in Ningbo University.
摘要Improvements to body-surface physiological monitoring ability including real-time,accuracy and integration,are essential to meet the expansive demands for personal healthcare.As part of this,simultaneous monitoring of sweat metabolites and body temperature offers an exciting path to maximizing diagnostic precision and minimizing morbidity rates.Herein,we report a high-performance biomarker-temperature sensor made of a single As3Se5Te2chalcogenide glass fiber to monitor physiology evolution on body-surface.The sensor integrates efficient thermal resistance and fiber evanescent wave effects,permitting the independent sensing of temperature and biomarkers with an ultrahigh temperature coefficient of resistance(−5.84%K–1),rapid temperature response(0.3 s)and excellent IR sensing sensitivity.Moreover,by attaching a fiber to the wrist,we demonstrate simultaneous observation of both sweat metabolite(urea and lactate)and temperature changes during exercise.This illuminating sensing method will provide crucial capabilities in physiological monitoring and pave the way for advanced personalized diagnostic.
基金support from the National Natural Science Foundation of China(Grant No.62090064)Key Research&Development Program of Ningbo City(Grant No.2022Z208).
摘要In this paper,a graphene oxide(GO)composite film-coated humidity sensor is proposed based on the hollow core fiber(HCF).A segment of the HCF is spliced between two segments of the single-mode fiber(SMF).The relative humidity(RH)sensing characteristics of the sensor are experimentally investigated by observing the intensity shift of resonant dips in the transmission spectrum,which shows the GO composite film-coated HCF has the good stability in the measurement of humidity.The maximum humidity sensitivity of 0.12 dB/%RH is obtained in the RH range of 30%–78%.The proposed sensor has the advantages of the simple structure,easy fabrication,good stability,and high performance,which can be applied to marine climate detection,tunnel air humidity detection,agricultural testing,and other fields.
基金National Natural Science Foundations of China(NSFCs)(Nos.61875094,62090064)K.C.Wong Magna Fund in Ningbo University.
摘要Chalcogenide(ChG)glasses have the characteristics of a wide transparency window(over 20μm)and high optical nonlinearity(up to 103 times greater than that of silica glasses),exhibiting great advantages over silica and other soft glasses in optical property at mid-infrared(MIR)wavelength range.These make them excellent candidates for MIR supercontinuum(SC)generation.Over the past decades,great progress has been made in MIR SC generation based on ChG fibers in terms of spectral extension and output power improvement.In this paper,we introduce briefly the properties of ChG glasses and fibers including transmission,nonlinearity,and dispersion,etc.Recent progress in MIR SC generation based on ChG fibers is reviewed from the perspective of pump schemes.We also present novel ChG fibers such as As-free,Te-based,and chalcohalide fibers,which have been explored and employed as nonlinear fibers to achieve broadband SC generation.Moreover,the potential applications of MIR SC sources based on ChG fibers are discussed.
基金supported by the National Natural Science Foundation of China(NSFC)(No.61805124)Natural Science Foundation of Ningbo City,China(No.2018A610023)+1 种基金3315 Innovation Team in Ningbo City,Zhejiang Province,ChinaK.C.Wong Magna Fund in Ningbo University,China。
摘要We report on the investigation of intermode beating mode-locked(IBML)pulse generation in a simple all-fiber Tm^3+-doped double clad fiber laser(TDFL).This IBML TDFL is implemented by matching longitudinal-mode frequency between 793 nm laser and TDFL without extra mode locker.The central wavelength of 1983 nm,the fundamental pulse frequency of 9.6 MHz and the signal-to-noise ratio(SNR)of>50 dB are achieved in this IBML TDFL.With laser cavity optimization,the IBML TDFL can finally generate an average output power of 1.03 W with corresponding pulse energy of 107 nJ.These results can provide an easily accessible way to develop compact large-energy,highpower TDFLs.
基金supported by the National Natural Science Foundation of China(Nos.62275134,62234008,61875098,and 61874078)the Zhejiang Provincial Natural Science Foundation(Nos.LY20F050003 and LY20F050001)+2 种基金the Natural Science Foundation of Ningbo(Nos.2022J099 and 202003N4159)the Youth Science and Technology Innovation Leading Talent Project of Ningbo(No.2023QL003)the K.C.Wong Magna Fund at Ningbo University。
摘要A flexible-grid 1×(2×3)mode-and wavelength-selective switch which comprises counter-tapered couplers and silicon microring resonators has been proposed,optimized,and demonstrated experimentally in this work.By carefully thermally tuning phase shifters and silicon microring resonators,mode and wavelength signals can be independently and flexibly conveyed to any one of the output ports,and different bandwidths can be generated as desired.The particle swarm optimization algorithm and finite difference time-domain method are employed to optimize structural parameters of the twomode(de)multiplexer and crossing waveguide.The bandwidth-tunable wavelength-selective optical router composed of12 microring resonators is studied by taking advantage of the transfer matrix method.Measurement results show that,for the fabricated module,cross talk less than-10.18 dB,an extinction ratio larger than 17.41 d B,an in-band ripple lower than0.79 dB,and a 3-dB bandwidth changing from 0.38 to 1.05 nm are obtained,as the wavelength-channel spacing is 0.40 nm.The corresponding response time is measured to be 13.64μs.
基金supported by the National Natural Science Foundation of China(Nos.62275134,62234008,and 61875098)the Zhejiang Provincial Natural Science Foundation(Nos.LY20F050003 and LY20F050001)+2 种基金the Youth Science and Technology Innovation Leading Talent Project of Ningbo(No.2023QL003)the Natural Science Foundation of Ningbo(Nos.2022J099 and 202003N4159)the K.C.Wong Magna Fund in Ningbo University。
摘要A polarization-insensitive mode-order converting power splitter using a pixelated region is presented and investigated in this paper.As TE0and TM0modes are injected into the input port,they are converted into TE1and TM1modes,which evenly come out from the two output ports.The finite-difference time-domain method and direct-binary-search optimization algorithm are utilized to optimize structural parameters of the pixelated region to attain small insertion loss,low crosstalk,wide bandwidth,excellent power uniformity,polarization-insensitive property,and compact size.Experimental results reveal that the insertion loss,crosstalk,and power uniformity of the fabricated device at 1550 nm are 0.57,-19.67,and 0.094 d B in the case of TE polarization,while in the TM polarization,the relevant insertion loss,crosstalk,and power uniformity are 0.57,-19.40,and 0.11 d B.Within a wavelength range from 1520 to 1600 nm,for the fabricated device working at TE polarization,the insertion loss,crosstalk,and power uniformity are lower than 1.39,-17.64,and 0.14 dB.In the case of TM polarization,we achieved an insertion loss,crosstalk,and power uniformity less than 1.23,-17.62,and 0.14 dB.