The mode-division multiplexing technique combined with a few-mode erbium-doped fiber amplifier(FM-EDFA)demonstrates significant potential for solving the capacity limitation of standard single-mode fiber(SSMF)transmis...The mode-division multiplexing technique combined with a few-mode erbium-doped fiber amplifier(FM-EDFA)demonstrates significant potential for solving the capacity limitation of standard single-mode fiber(SSMF)transmission systems.However,the differential mode gain(DMG)arising in the FM-EDFA fundamentally limits its transmission capacity and length.Herein,an innovative DMG equalization strategy using femtosecond laser micromachining to adjust the refractive index(RI)is presented.Variable mode-dependent attenuations can be achieved according to the DMG profile of the FM-EDFA,enabling DMG equalization.To validate the proposed strategy,DMG equalization of the commonly used FM-EDFA configuration was investigated.Simulation results revealed that by optimizing both the length and RI modulation depth of the femtosecond laser-tailoring area,the maximum DMG(DMGmax)among the 3 linear-polarized(LP)mode-group was mitigated from 10 dB to 1.52 dB,whereas the average DMG(DMGave)over the C-band was reduced from 8.95 dB to 0.78 dB.Finally,a 2-LP mode-group DMG equalizer was experimentally demonstrated,resulting in a reduction of the DMGmax from 2.09 dB to 0.46 dB,and a reduction of DMGave over the C band from 1.64 dB to 0.26 dB,with only a 1.8 dB insertion loss.Moreover,a maximum range of variable DMG equalization was achieved with 5.4 dB,satisfying the requirements of the most commonly used 2-LP mode-group amplification scenarios.展开更多
We report on second harmonic generation(SHG) in on-chip high-Q(>105) lithium niobate(Li Nb O3, LN) microresonators fabricated by femtosecond laser micromachining. We examine the efficiency of SHG with either a cont...We report on second harmonic generation(SHG) in on-chip high-Q(>105) lithium niobate(Li Nb O3, LN) microresonators fabricated by femtosecond laser micromachining. We examine the efficiency of SHG with either a continuous-wave(CW) or an ultrashort pulsed pump laser. The normalized conversion efficiencies of SHG obtained with the CW and pulsed pump lasers are measured to be 1.35×10?5 m W?1 and 2.30×10?6 m W?1, respectively.展开更多
The importance of integrated quantum photonics in the telecom band is based on the possibility of interfacing with the optical network infrastructure that was developed for classical communications.In this framework,f...The importance of integrated quantum photonics in the telecom band is based on the possibility of interfacing with the optical network infrastructure that was developed for classical communications.In this framework,femtosecond laser-written integrated photonic circuits,which have already been assessed for use in quantum information experiments in the 800-nm wavelength range,have great potential.In fact,these circuits,being written in glass,can be perfectly mode-matched at telecom wavelength to the in/out coupling fibers,which is a key requirement for a low-loss processing node in future quantum optical networks.In addition,for several applications,quantum photonic devices must be dynamically reconfigurable.Here,we experimentally demonstrate the high performance of femtosecond laser-written photonic circuits for use in quantum experiments in the telecom band,and we demonstrate the use of thermal shifters,which were also fabricated using the same femtosecond laser,to accurately tune such circuits.State-of-the-art manipulation of single-and two-photon states is demonstrated,with fringe visibilities greater than 95%.The results of this work open the way to the realization of reconfigurable quantum photonic circuits based on this technological platform.展开更多
Perovskite materials have become a popular research topic because of their unique optical and electrical properties,that enable extensive applications in information storage,lasers,anti-counterfeiting,and planar lense...Perovskite materials have become a popular research topic because of their unique optical and electrical properties,that enable extensive applications in information storage,lasers,anti-counterfeiting,and planar lenses.However,the success of the application depends on accomplishing high-precision and high-quality perovskite patterning technology.Numerous methods have been proposed for perovskite production,including,a femtosecond laser with an ultrashort pulse width and ultrahigh peak power with unique advantages such as high precision and efficiency,nonlinearity,and excellent material adaptability in perovskite material processing.Furthermore,femtosecond lasers can induce precipitation of perovskite inside glass/crystals,which markedly enhances the stability of perovskite materials and promotes their application and development in various fields.This review introduces perovskite precipitation and processing via femtosecond lasers.The methods involved and advantages of femtosecond-laser-induced perovskite precipitation and patterning are systematically summarized.The review also provides an outlook for further optimization and improvement of femtosecond laser preparation and processing methods for perovskites,which may offer significant support for future research and applications of perovskite materials.展开更多
Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits.Benefiting from their high optical confinement and miniaturized footprints,waveguide structures established base...Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits.Benefiting from their high optical confinement and miniaturized footprints,waveguide structures established based on crystalline materials,particularly,are opening exciting possibilities and opportunities in photonic chips by facilitating their on-chip integration with different functionalities and highly compact photonic circuits.Femtosecond-laser-direct writing(FsLDW),as a true three-dimensional(3D)micromachining and microfabrication technology,allows rapid prototyping of on-demand waveguide geometries inside transparent materials via localized material modification.The success of FsLDW lies not only in its unsurpassed aptitude for realizing 3D devices but also in its remarkable material-independence that enables cross-platform solutions.This review emphasizes FsLDW fabrication of waveguide structures with 3D layouts in dielectric crystals.Their functionalities as passive and active photonic devices are also demonstrated and discussed.展开更多
In this article,we review recent advances in the technology of writing fiber Bragg gratings(FBGs)in selected cores of multicore fibers(MCFs)by using femtosecond laser pulses.The writing technology of such a key elemen...In this article,we review recent advances in the technology of writing fiber Bragg gratings(FBGs)in selected cores of multicore fibers(MCFs)by using femtosecond laser pulses.The writing technology of such a key element as the FBG opens up wide opportunities for the creation of next generation fiber lasers and sensors based on MCFs.The advantages of the technology are shown by using the examples of 3D shape sensors,acoustic emission sensors with spatially multiplexed channels,as well as multicore fiber Raman lasers.展开更多
A novel laser processing technique was developed for making channels in the nano regime in this paper.A Nd:YAG laser was used to dry fabricate micro channels(25μm～100μm di- ameter)in a 1 cm^3 fused silica substrate...A novel laser processing technique was developed for making channels in the nano regime in this paper.A Nd:YAG laser was used to dry fabricate micro channels(25μm～100μm di- ameter)in a 1 cm^3 fused silica substrate by thermal-induced processing.By controlling the locations of these initiating micro channels on a silica cube,1D-controllable self-connecting nano fractures can be formed as rectangular channels.These nano channels are smooth and with extremely high aspect ratio(～10~4 depth to width ratio).A possible mechanism is proposed to explain the formation of the nano channels.This laser-based nano channel fabrication technique is fast and inexpensive,and with potential applications in capillary electrophoresis and electro-osmosis driven nano-filtration.展开更多
Optical fibers are typically used in telecommunications services for data transmission,where the use of fiber tags is essential to distinguish between the different transmission fibers or channels and thus ensure the ...Optical fibers are typically used in telecommunications services for data transmission,where the use of fiber tags is essential to distinguish between the different transmission fibers or channels and thus ensure the working functionality of the communication system.Traditional physical entity marking methods for fiber labeling are bulky,easily confused,and,most importantly,the label information can be accessed easily by all potential users.This work proposes an encrypted optical fiber tag based on an encoded fiber Bragg grating(FBG)array that is fabricated using a point-by-point femtosecond laser pulse chain inscription method.Gratings with different resonant wavelengths and reflectivities are realized by adjusting the grating period and the refractive index modulations.It is demonstrated that a binary data sequence carried by a fiber tag can be inscribed into the fiber core in the form of an FBG array,and the tag data can be encrypted through appropriate design of the spatial distributions of the FBGs with various reflection wavelengths and reflectivities.The proposed fiber tag technology can be used for applications in port identification,encrypted data storage,and transmission in fiber networks.展开更多
Recent developments in the utilization of microfluidic chips(MFCs) have shown their potential utility in multiphase organic synthesis by enabling efficient organic reactions in flow chemistry. However, MFCs technology...Recent developments in the utilization of microfluidic chips(MFCs) have shown their potential utility in multiphase organic synthesis by enabling efficient organic reactions in flow chemistry. However, MFCs technology has been wandering in the laboratory of small dose synthetic routes, which is limited to the level of "tiny" fluid flux. To address this issue, we herein report the first case of the chips with highthroughput 3D channels produced by femtosecond laser being used to create a time-saving, cost-effective and risk-free approach suitable for large-scale flow synthesis. Several multiphase reactions have been successfully prepared on demand in our designed flow synthesis system containing 3D MFCs: 1) benzyl alcohol was converted to benzaldehyde in 3 min with a yield of 97.50% by liquid-liquid two-phase transfer catalytic oxidation;2) organozinc reagents and α-cyano carbonyl carbon compounds were synthesized by solid-liquid two-phase metal insertion reaction in 7 min, and the yield was up to 100%;3) benzoic acid was synthesized by gas-liquid two-phase carboxylation reaction in 2.8 s with a yield of 96%. Significant gains in production rate result from the effective scaling of flow reactors from microliters per hour in MFCs to intermediate milliliters per minute without affecting mass transport performance. Meanwhile,our 3D MFCs show excellent mass and heat transfer efficiency in large-scale industrial units, breaking through the bottleneck in this field. As a result, it is possible to imagine the creation of a new, streamlined flow synthetic technique via MFCs for green multiphase organic synthesis.展开更多
Fiber-based curvature sensors,especially those capable of discerning the direction of curvature,have attracted more and more interest due to their promising applications in structural health monitoring,high-precision ...Fiber-based curvature sensors,especially those capable of discerning the direction of curvature,have attracted more and more interest due to their promising applications in structural health monitoring,high-precision measurement,medical and biological diagnosis-treat instruments,and so on.Here,we propose and demonstrate a compact directional curvature sensor that comprises two bridged waveguides and three Bragg gratings in a section of three-core fiber(TCF).Both the waveguides and gratings are integrated by femtosecond laser micromachining method.The waveguides,connecting the TCF outer cores to the lead-in single-mode fiber core,function as beam couplers to realize simultaneous interrogation of all three gratings without any separate fan-in/out component.Owing to the spatial specificity,the outer-core gratings exhibit high and direction-dependent sensitivity to curvature,whereas the central-core grating is nearly insensitive to curvature but shows similar sensitivities to ambient temperature and axial strain as the outer-core gratings.It can be used to compensate the cross impact of temperature and strain when the outer-core gratings are applied for curvature detection.Moreover,the wavelength interval between two outer-core gratings is also proposed as an indicator for curvature sensing.It features with a much higher sensitivity to curvature and reduced sensitivities to temperature and axial strain.The corresponding maximum sensitivity to curvature is as high as 191.89 pm/m-1,while the sensitivities to temperature and strain are only 0.3 pm/℃and 0.0218 pm/με,respectively.Therefore,our proposed device provides a compact and robust all-infiber solution for directional curvature sensing.It not only offers high sensitivity and accuracy but also immunity to temperature and axial strain fluctuations,making it a promising tool for a wide range of applications.展开更多
The femtosecond laser has been an efficient tool for optical fiber high temperature sensor construction.Here,we review the progress of optical fiber high temperature sensors based on femtosecond laser fabricated fiber...The femtosecond laser has been an efficient tool for optical fiber high temperature sensor construction.Here,we review the progress of optical fiber high temperature sensors based on femtosecond laser fabricated fiber gratings and various types of fiber in-line interferometers in silica fibers and sapphire fibers.展开更多
Despite the continuously increased requirement on automated synthesis of medicines for distributed manufacturing and personal care, it remains a challenge to realize automated synthesis which requires solid-liquid pha...Despite the continuously increased requirement on automated synthesis of medicines for distributed manufacturing and personal care, it remains a challenge to realize automated synthesis which requires solid-liquid phase reactions. In this work, we demonstrated an automated solid-liquid synthesis for gadopentetate dimeglumine, the most widely used magnetic resonance imaging(MRI) contrast agent. The high-efficiency reaction was performed in a 3D microfluidic chip which was fabricated by femtosecond laser micromachining. The structure of the chip realized 3D shear flow which was essential for highly efficient mixing and movement of the solid-liquid mixtures. Ultraviolet visible(UV-vis) spectrometer was employed for in-line analysis to help automation of this system. Comparing with the round-bottom flask system, this synthetic system showed significantly higher reaction rate, indicating the advantage of the3D microfluidic technology in micro chemical engineering.展开更多
Fiber Bragg grating is inscribed on microfiber with femtosecond laser pulses irradiation. The microfiber is fabricated by stretching a section of single mode fiber over a flame. Periodic grooves are carved on the micr...Fiber Bragg grating is inscribed on microfiber with femtosecond laser pulses irradiation. The microfiber is fabricated by stretching a section of single mode fiber over a flame. Periodic grooves are carved on the microfiber by the laser as have been observed experimentally. The microfiber Bragg grating is demonstrated for temperature and strain sensing, and the strain sensitivity is improved with decreased diameters of the microfibers.展开更多
Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications,however,is facing challenges due to lack of in-situ method for size-characterization in fluidic en...Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications,however,is facing challenges due to lack of in-situ method for size-characterization in fluidic environment.We present that ultraviolet-visible(UV-vis)absorption spectroscopy can be integrated into a flow-synthesis system which was produced by femtosecond laser micro machining.The shift of the absorption peak position of the ex-situ and in-situ UV-vis spectra correlates to variation of size of porous metal-organic frameworks crystals.ZIF-67 crystals with a size in the range from 200 nm to1025 nm are fabricated with the assistance of tri-ethylamine under monitoring of in-situ UV-vis spectra.The ZIF-67 crystals are converted into nanoporous carbons particles with controlled sizes.These materials show size-dependent performance in Na-ion battery and size-independent performance in metal/H_(2)O seawater battery.展开更多
基金supported by the National Natural Science Foundation of China(62305071)China Postdoctoral Science Foundation(2023M740747)Guangdong Introducing Innovative and Entrepreneurial Teams of“The Pearl River Talent Recruitment Program”(2021ZT09X044).
文摘The mode-division multiplexing technique combined with a few-mode erbium-doped fiber amplifier(FM-EDFA)demonstrates significant potential for solving the capacity limitation of standard single-mode fiber(SSMF)transmission systems.However,the differential mode gain(DMG)arising in the FM-EDFA fundamentally limits its transmission capacity and length.Herein,an innovative DMG equalization strategy using femtosecond laser micromachining to adjust the refractive index(RI)is presented.Variable mode-dependent attenuations can be achieved according to the DMG profile of the FM-EDFA,enabling DMG equalization.To validate the proposed strategy,DMG equalization of the commonly used FM-EDFA configuration was investigated.Simulation results revealed that by optimizing both the length and RI modulation depth of the femtosecond laser-tailoring area,the maximum DMG(DMGmax)among the 3 linear-polarized(LP)mode-group was mitigated from 10 dB to 1.52 dB,whereas the average DMG(DMGave)over the C-band was reduced from 8.95 dB to 0.78 dB.Finally,a 2-LP mode-group DMG equalizer was experimentally demonstrated,resulting in a reduction of the DMGmax from 2.09 dB to 0.46 dB,and a reduction of DMGave over the C band from 1.64 dB to 0.26 dB,with only a 1.8 dB insertion loss.Moreover,a maximum range of variable DMG equalization was achieved with 5.4 dB,satisfying the requirements of the most commonly used 2-LP mode-group amplification scenarios.
基金supported by the National Key Basic Research Program of China(Grant No.2014CB921300)the National Natural Science Foundation of China(Grant Nos.61275205,11174305 and 61205209)the Fundamental Research Funds for the Central Universities
文摘We report on second harmonic generation(SHG) in on-chip high-Q(>105) lithium niobate(Li Nb O3, LN) microresonators fabricated by femtosecond laser micromachining. We examine the efficiency of SHG with either a continuous-wave(CW) or an ultrashort pulsed pump laser. The normalized conversion efficiencies of SHG obtained with the CW and pulsed pump lasers are measured to be 1.35×10?5 m W?1 and 2.30×10?6 m W?1, respectively.
基金This work was supported by the ERC-Starting Grant 3D-QUEST(3DQuantum Integrated Optical Simulationgrant agreement no.307783,http://www.3dquest.eu)by the Marie Curie Initial Training Network PICQUE(Photonic Integrated Compound Quantum Encoding,grant agreement no.608062,funding Program:FP7-PEOPLE-2013-ITN,http://www.picque.eu).
文摘The importance of integrated quantum photonics in the telecom band is based on the possibility of interfacing with the optical network infrastructure that was developed for classical communications.In this framework,femtosecond laser-written integrated photonic circuits,which have already been assessed for use in quantum information experiments in the 800-nm wavelength range,have great potential.In fact,these circuits,being written in glass,can be perfectly mode-matched at telecom wavelength to the in/out coupling fibers,which is a key requirement for a low-loss processing node in future quantum optical networks.In addition,for several applications,quantum photonic devices must be dynamically reconfigurable.Here,we experimentally demonstrate the high performance of femtosecond laser-written photonic circuits for use in quantum experiments in the telecom band,and we demonstrate the use of thermal shifters,which were also fabricated using the same femtosecond laser,to accurately tune such circuits.State-of-the-art manipulation of single-and two-photon states is demonstrated,with fringe visibilities greater than 95%.The results of this work open the way to the realization of reconfigurable quantum photonic circuits based on this technological platform.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2022A1515011951,2023A1515012977,2024A1515010109)the National Natural Science Foundation of China(62375056)the Science and Technology Program of Guangzhou(202201010182).
文摘Perovskite materials have become a popular research topic because of their unique optical and electrical properties,that enable extensive applications in information storage,lasers,anti-counterfeiting,and planar lenses.However,the success of the application depends on accomplishing high-precision and high-quality perovskite patterning technology.Numerous methods have been proposed for perovskite production,including,a femtosecond laser with an ultrashort pulse width and ultrahigh peak power with unique advantages such as high precision and efficiency,nonlinearity,and excellent material adaptability in perovskite material processing.Furthermore,femtosecond lasers can induce precipitation of perovskite inside glass/crystals,which markedly enhances the stability of perovskite materials and promotes their application and development in various fields.This review introduces perovskite precipitation and processing via femtosecond lasers.The methods involved and advantages of femtosecond-laser-induced perovskite precipitation and patterning are systematically summarized.The review also provides an outlook for further optimization and improvement of femtosecond laser preparation and processing methods for perovskites,which may offer significant support for future research and applications of perovskite materials.
基金financial support from National Natural Science Foundation of China(No.61775120).
文摘Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits.Benefiting from their high optical confinement and miniaturized footprints,waveguide structures established based on crystalline materials,particularly,are opening exciting possibilities and opportunities in photonic chips by facilitating their on-chip integration with different functionalities and highly compact photonic circuits.Femtosecond-laser-direct writing(FsLDW),as a true three-dimensional(3D)micromachining and microfabrication technology,allows rapid prototyping of on-demand waveguide geometries inside transparent materials via localized material modification.The success of FsLDW lies not only in its unsurpassed aptitude for realizing 3D devices but also in its remarkable material-independence that enables cross-platform solutions.This review emphasizes FsLDW fabrication of waveguide structures with 3D layouts in dielectric crystals.Their functionalities as passive and active photonic devices are also demonstrated and discussed.
基金supported by the Russian Ministry of Science and Higher Education (14.Y26.31.0017)Russian Foundation for Basic Research(18-52-7822)the work concerning MCF fiber Raman lasers was supported by Russian Science Foundation (21-72-30024)
文摘In this article,we review recent advances in the technology of writing fiber Bragg gratings(FBGs)in selected cores of multicore fibers(MCFs)by using femtosecond laser pulses.The writing technology of such a key element as the FBG opens up wide opportunities for the creation of next generation fiber lasers and sensors based on MCFs.The advantages of the technology are shown by using the examples of 3D shape sensors,acoustic emission sensors with spatially multiplexed channels,as well as multicore fiber Raman lasers.
基金The project supported by the National Natural Science Foundation of China (50375031)the Hong Kong Research Grants Council (CUHK 4416/99E)
文摘A novel laser processing technique was developed for making channels in the nano regime in this paper.A Nd:YAG laser was used to dry fabricate micro channels(25μm～100μm di- ameter)in a 1 cm^3 fused silica substrate by thermal-induced processing.By controlling the locations of these initiating micro channels on a silica cube,1D-controllable self-connecting nano fractures can be formed as rectangular channels.These nano channels are smooth and with extremely high aspect ratio(～10~4 depth to width ratio).A possible mechanism is proposed to explain the formation of the nano channels.This laser-based nano channel fabrication technique is fast and inexpensive,and with potential applications in capillary electrophoresis and electro-osmosis driven nano-filtration.
基金supported by the National Natural Science Foundation of China(62122057,62075136,62105217,62205221,62205222)the Basic and Applied Basic Research Foundation of Guangdong Province(2022B1515120061)Shenzhen Science and Technology Program(Shenzhen Key Laboratory of Ultrafast Laser Micro/Nano Manufacturing ZDSYS20220606100405013,RCYX20200714114524139,JCYJ20200109114001806)。
文摘Optical fibers are typically used in telecommunications services for data transmission,where the use of fiber tags is essential to distinguish between the different transmission fibers or channels and thus ensure the working functionality of the communication system.Traditional physical entity marking methods for fiber labeling are bulky,easily confused,and,most importantly,the label information can be accessed easily by all potential users.This work proposes an encrypted optical fiber tag based on an encoded fiber Bragg grating(FBG)array that is fabricated using a point-by-point femtosecond laser pulse chain inscription method.Gratings with different resonant wavelengths and reflectivities are realized by adjusting the grating period and the refractive index modulations.It is demonstrated that a binary data sequence carried by a fiber tag can be inscribed into the fiber core in the form of an FBG array,and the tag data can be encrypted through appropriate design of the spatial distributions of the FBGs with various reflection wavelengths and reflectivities.The proposed fiber tag technology can be used for applications in port identification,encrypted data storage,and transmission in fiber networks.
基金supported by the Shanghai Municipal Science and Technology Major Project (“Beyond Limits manufacture”)。
文摘Recent developments in the utilization of microfluidic chips(MFCs) have shown their potential utility in multiphase organic synthesis by enabling efficient organic reactions in flow chemistry. However, MFCs technology has been wandering in the laboratory of small dose synthetic routes, which is limited to the level of "tiny" fluid flux. To address this issue, we herein report the first case of the chips with highthroughput 3D channels produced by femtosecond laser being used to create a time-saving, cost-effective and risk-free approach suitable for large-scale flow synthesis. Several multiphase reactions have been successfully prepared on demand in our designed flow synthesis system containing 3D MFCs: 1) benzyl alcohol was converted to benzaldehyde in 3 min with a yield of 97.50% by liquid-liquid two-phase transfer catalytic oxidation;2) organozinc reagents and α-cyano carbonyl carbon compounds were synthesized by solid-liquid two-phase metal insertion reaction in 7 min, and the yield was up to 100%;3) benzoic acid was synthesized by gas-liquid two-phase carboxylation reaction in 2.8 s with a yield of 96%. Significant gains in production rate result from the effective scaling of flow reactors from microliters per hour in MFCs to intermediate milliliters per minute without affecting mass transport performance. Meanwhile,our 3D MFCs show excellent mass and heat transfer efficiency in large-scale industrial units, breaking through the bottleneck in this field. As a result, it is possible to imagine the creation of a new, streamlined flow synthetic technique via MFCs for green multiphase organic synthesis.
文摘Fiber-based curvature sensors,especially those capable of discerning the direction of curvature,have attracted more and more interest due to their promising applications in structural health monitoring,high-precision measurement,medical and biological diagnosis-treat instruments,and so on.Here,we propose and demonstrate a compact directional curvature sensor that comprises two bridged waveguides and three Bragg gratings in a section of three-core fiber(TCF).Both the waveguides and gratings are integrated by femtosecond laser micromachining method.The waveguides,connecting the TCF outer cores to the lead-in single-mode fiber core,function as beam couplers to realize simultaneous interrogation of all three gratings without any separate fan-in/out component.Owing to the spatial specificity,the outer-core gratings exhibit high and direction-dependent sensitivity to curvature,whereas the central-core grating is nearly insensitive to curvature but shows similar sensitivities to ambient temperature and axial strain as the outer-core gratings.It can be used to compensate the cross impact of temperature and strain when the outer-core gratings are applied for curvature detection.Moreover,the wavelength interval between two outer-core gratings is also proposed as an indicator for curvature sensing.It features with a much higher sensitivity to curvature and reduced sensitivities to temperature and axial strain.The corresponding maximum sensitivity to curvature is as high as 191.89 pm/m-1,while the sensitivities to temperature and strain are only 0.3 pm/℃and 0.0218 pm/με,respectively.Therefore,our proposed device provides a compact and robust all-infiber solution for directional curvature sensing.It not only offers high sensitivity and accuracy but also immunity to temperature and axial strain fluctuations,making it a promising tool for a wide range of applications.
基金the National Key R&D Program of China(Grant No.2018YFB1107200)the National Natural Science Foundation of China(Grant Nos.51472091,51772270)Open funds of State Key Laboratory of Precision Spectroscopy,East China Normal University and State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences.
基金supported by the National Natural Science Foundation of China (No. 61975192)
文摘The femtosecond laser has been an efficient tool for optical fiber high temperature sensor construction.Here,we review the progress of optical fiber high temperature sensors based on femtosecond laser fabricated fiber gratings and various types of fiber in-line interferometers in silica fibers and sapphire fibers.
基金supported by National Natural Science Foundation of China (No.11674340)Key Project of the Shanghai Science and Technology Committee (No.18DZ1112700)。
文摘Despite the continuously increased requirement on automated synthesis of medicines for distributed manufacturing and personal care, it remains a challenge to realize automated synthesis which requires solid-liquid phase reactions. In this work, we demonstrated an automated solid-liquid synthesis for gadopentetate dimeglumine, the most widely used magnetic resonance imaging(MRI) contrast agent. The high-efficiency reaction was performed in a 3D microfluidic chip which was fabricated by femtosecond laser micromachining. The structure of the chip realized 3D shear flow which was essential for highly efficient mixing and movement of the solid-liquid mixtures. Ultraviolet visible(UV-vis) spectrometer was employed for in-line analysis to help automation of this system. Comparing with the round-bottom flask system, this synthetic system showed significantly higher reaction rate, indicating the advantage of the3D microfluidic technology in micro chemical engineering.
文摘Fiber Bragg grating is inscribed on microfiber with femtosecond laser pulses irradiation. The microfiber is fabricated by stretching a section of single mode fiber over a flame. Periodic grooves are carved on the microfiber by the laser as have been observed experimentally. The microfiber Bragg grating is demonstrated for temperature and strain sensing, and the strain sensitivity is improved with decreased diameters of the microfibers.
基金supported by National Natural Science Foundation of China(Nos.11674340,21473059)Key Project of the Shanghai Science and Technology Committee(No.18DZ1112700)。
文摘Size-controlled flow synthesis of nanoporous particles are of considerable interest for future industrial applications,however,is facing challenges due to lack of in-situ method for size-characterization in fluidic environment.We present that ultraviolet-visible(UV-vis)absorption spectroscopy can be integrated into a flow-synthesis system which was produced by femtosecond laser micro machining.The shift of the absorption peak position of the ex-situ and in-situ UV-vis spectra correlates to variation of size of porous metal-organic frameworks crystals.ZIF-67 crystals with a size in the range from 200 nm to1025 nm are fabricated with the assistance of tri-ethylamine under monitoring of in-situ UV-vis spectra.The ZIF-67 crystals are converted into nanoporous carbons particles with controlled sizes.These materials show size-dependent performance in Na-ion battery and size-independent performance in metal/H_(2)O seawater battery.
