Side polished fiber(SPF)has a controllable average roughness and length of the side-polishing region,which becomes a versatile platform for integrating multiple materials to interact with the evanescent field to fabri...Side polished fiber(SPF)has a controllable average roughness and length of the side-polishing region,which becomes a versatile platform for integrating multiple materials to interact with the evanescent field to fabricate all-fiber devices and sensors.It has been widely used in couplers,filters,polarizers,optical attenuators,photodetectors,modulators,and sensors for temperature,humidity,strain,biological molecules,chemical gas,and vector magnetic monitoring.In this article,an overview of the development history,fabrication techniques,fiber types,transmission characteristics,and varied recent applications of SPFs are reviewed.Firstly,the fabrication techniques of SPFs are reviewed,including the V-groove assisted polishing technique and wheel polishing technique.Then,the different types of SPFs and their characteristics are discussed.Finally,various applications of SPFs are discussed and concluded theoretically and experimentally,including their principles and structures.When designing the device,the residual thickness and polishing lengths of the SPF need to be appropriately selected in order to obtain the best performance.Developing all-fiber devices and sensors is aimed at practical usability under harsh environments and allows to avoid the high coupling loss between optical fibers and on-chip integrated devices.展开更多
Herein we propose a novel strategy to enhance surface plasmon resonance(SPR)by introducing a photonic cavity into a total-internal-reflection architecture.The photonic cavity,which is comprised of a highly reflective ...Herein we propose a novel strategy to enhance surface plasmon resonance(SPR)by introducing a photonic cavity into a total-internal-reflection architecture.The photonic cavity,which is comprised of a highly reflective photonic crystal(PC),defect layers,and a gold(Au)film,enables Fabry–Perot(FP)resonances in the defect layers and therefore narrows the SPR resonance width in the metallic surface as well as increases the electric field intensity and penetration depth in the evanescent region.The fabricated sensor exhibits a 5.7-fold increase in the figure of merit and a higher linear coefficient as compared with the conventional Au-SPR sensor.The demonstrated PC/FP cavity/metal structure presents a new design philosophy for SPR performance enhancement.展开更多
A novel magnetic field sensing system based on the fiber loop ring-down technique is proposed in this paper. In the fiber loop, a U-bent single-mode-fiber structure coated with magnetic fluid(MF) serves as the sensing...A novel magnetic field sensing system based on the fiber loop ring-down technique is proposed in this paper. In the fiber loop, a U-bent single-mode-fiber structure coated with magnetic fluid(MF) serves as the sensing head, and an erbium-doped fiber amplifier(EDFA) is introduced to compensate for the intrinsic loss of the cavity. The ring-down time of the system varies with the change of applied magnetic field due to the tunable absorption coefficient and refractive index of the MF. Therefore, measurement of the magnetic field can be realized by monitoring the ringdown time. The experimental results show that the performance of the system is extremely dependent on the interrogation wavelength, because both the gain of the EDFA and the loss of the sensing head are wavelength dependent.We found that at the optimal wavelength, the ratio of the gain to loss attained its maximum. The sensing system was experimentally demonstrated and a sensitivity of-0.5951 μs∕Oe was achieved.展开更多
In this paper, Er/Yb co-doped fiber amplifiers(EYDFAs) with an Yb-band fiber Bragg grating(FBG) at the pump end to improve the performance of the amplifier is systematically studied. The influence of the reflectivity ...In this paper, Er/Yb co-doped fiber amplifiers(EYDFAs) with an Yb-band fiber Bragg grating(FBG) at the pump end to improve the performance of the amplifier is systematically studied. The influence of the reflectivity and center wavelength of the FBG along with the gain-fiber length on the performance of an EYDFA are numerically analyzed. The results show that the wavelength of the FBG has critical influence on the efficiency of the EYDFA,whereas the requirement to its reflectivity is relaxed. It is an effective and promising way to improve the efficiency of a high-power pumped EYDFA by introducing a suitable Yb-band FBG at the pump end. Based on the analysis of the underlying principles, suggestions for the practical design and possible further improvement strategies are also proposed.展开更多
Silver nanowire(AgNW)based transparent electrode(TE)plays a pivotal role in optoelectronics where TE is generally required to have fine pattern and high performance.Despite the rapid technological advances in either w...Silver nanowire(AgNW)based transparent electrode(TE)plays a pivotal role in optoelectronics where TE is generally required to have fine pattern and high performance.Despite the rapid technological advances in either welding or patterning of AgNWs,there are few studies that combine the two processes in a simple and practical manner.Here,aiming to fabricate high-performance patterned AgNW TE,we develop a simplified photolithography that enables both plasmonic nanowelding with low-level UV exposure(20 mW/cm^(2))and high-resolution micropatterning without photoresist and etching process by conjugating AgNW with diphenyliodonium nitrate(DPIN)and UV-curable cellulose.The cellulose as a binder can effectively enhance plasmonic heating,adhesion,and stability,while the photosensitive DPIN,capable of modulating surface atom diffusion,can boost the plasmonic welding at AgNW junction and induce patterning in AgNW network with Plateau-Rayleigh instability.The fabricated AgNW TE has high figure of merit of up to 1,000(3.7Ω/sq at 90%transmittance)and minimal pattern size down to 3µm,along with superior robustness.Finally,a flexible smart window with high performance is demonstrated using the patterned and welded AgNW TEs,verifying the applicability of the simplified photolithography technique to optoelectronic devices.展开更多
Hyperbolic metamaterials(HMMs) are novel artificial materials that excite the surface plasmon resonance(SPR) because of their unique hyperbolic dispersion properties. Herein, to the best of our knowledge, we propose t...Hyperbolic metamaterials(HMMs) are novel artificial materials that excite the surface plasmon resonance(SPR) because of their unique hyperbolic dispersion properties. Herein, to the best of our knowledge, we propose the first HMM-based fiber SPR(HMM-SPR) sensor for vector magnetic detection. By selecting the composite materials and structural parameters of the HMM dispersion management, HMM-SPR sensors can achieve a high refractive index sensitivity of 14.43 μm/RIU. Vector magnetic field detection was performed with the HMM-SPR sensor encapsulated with a magnetic fluid. Compared with other ferrofluidbased magnetic field fiber sensors, the proposed sensor shows pronounced advantages in intensity and direction sensitivity of 1.307 nm/Oe and 7.116 nm/°, respectively. The sensor design approach presented in this paper provides an excellent demonstration of HMM-SPR sensors in various applications.展开更多
Patterned silver nanowire(AgNW)networks have been widely used as transparent electrodes in many optoelectrical devices.However,obvious patterning visibility and poor thermostability of AgNW are still limiting its prac...Patterned silver nanowire(AgNW)networks have been widely used as transparent electrodes in many optoelectrical devices.However,obvious patterning visibility and poor thermostability of AgNW are still limiting its practical application.Herein,we report self-assembled monolayer(SAM)modulated Plateau-Rayleigh instability(PRI)of AgNW,which allows invisible patterning and superior stability of the AgNW network.Two opposite effects of different SAMs on the PRI are identified:the alkanethiol SAMs activate surface atom diffusion while the mercaptobenzoheterocyclic(MBH)SAMs suppress the diffusion.The degradation temperature of the AgNWs can be therefore,for the first time,tuned in the range of 193-381℃,so that the AgNW network can be patterned via PRI with a tiny optical difference between the insulative and conductive regions,i.e.,patterning invisible.Besides,the MBH SAMs provide AgNW with excellent durability under thermal annealing and oxidation,which enhances the maximum heating temperature of the AgNW transparent heater by over 120℃.Beyond the micro-patterning,we consider that the developed SAM strategy can be extended to other metal nanowires for stability improvement and has huge potential in nanoengineering of one-dimensional metal materials.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12174155,61705086,61675092,and 62075088)National Key Research and Development Program of China(Grant Nos.2021YFB2800801 and 2018YFB1801900)+7 种基金Natural Science Foundation of Guangdong Province for Distinguished Young Scholar(Grant No.2020B1515020024)Natural Science Foundation of Guangdong Province(Grant Nos.2017A030313375and 2019A1515011380)Key-Area Research and Development Program of Guangdong Province(Grant No.2019B010138004)Project of Guangzhou Industry Leading Talents(Grant No.CXLJTD-201607)Aeronautical Science Foundation of China(Grant Nos.201708W4001 and 201808W4001)Project of STRPAT of EC Laboratory(Grant No.ZHD201902)TESTBED2(Grant No.H2020-MSCA-RISE-2019)Jinan Outstanding Young Scholar Support Program(Grant Nos.JNSBYC-2020040 and JNSBYC-2020117).
文摘Side polished fiber(SPF)has a controllable average roughness and length of the side-polishing region,which becomes a versatile platform for integrating multiple materials to interact with the evanescent field to fabricate all-fiber devices and sensors.It has been widely used in couplers,filters,polarizers,optical attenuators,photodetectors,modulators,and sensors for temperature,humidity,strain,biological molecules,chemical gas,and vector magnetic monitoring.In this article,an overview of the development history,fabrication techniques,fiber types,transmission characteristics,and varied recent applications of SPFs are reviewed.Firstly,the fabrication techniques of SPFs are reviewed,including the V-groove assisted polishing technique and wheel polishing technique.Then,the different types of SPFs and their characteristics are discussed.Finally,various applications of SPFs are discussed and concluded theoretically and experimentally,including their principles and structures.When designing the device,the residual thickness and polishing lengths of the SPF need to be appropriately selected in order to obtain the best performance.Developing all-fiber devices and sensors is aimed at practical usability under harsh environments and allows to avoid the high coupling loss between optical fibers and on-chip integrated devices.
基金National Natural Science Foundation of China(61575084,61805108,61904067)Science and Technology Planning Project of Guangdong Province(2014B010117002,2017A010101013)+2 种基金Science Technology Project of Guangzhou(201605030002,201704030105,201707010500,201807010077)Joint Fund of Pre-research for Equipment,and Ministry of Education of China(6141A02022124)Fundamental Research Funds for the Central Universities(21618404)。
文摘Herein we propose a novel strategy to enhance surface plasmon resonance(SPR)by introducing a photonic cavity into a total-internal-reflection architecture.The photonic cavity,which is comprised of a highly reflective photonic crystal(PC),defect layers,and a gold(Au)film,enables Fabry–Perot(FP)resonances in the defect layers and therefore narrows the SPR resonance width in the metallic surface as well as increases the electric field intensity and penetration depth in the evanescent region.The fabricated sensor exhibits a 5.7-fold increase in the figure of merit and a higher linear coefficient as compared with the conventional Au-SPR sensor.The demonstrated PC/FP cavity/metal structure presents a new design philosophy for SPR performance enhancement.
基金National Key Scientific Instrument and Equipment Development Project of China(2013YQ03091502)National Natural Science Foundation of China(NSFC)(61378043,61107035)
文摘A novel magnetic field sensing system based on the fiber loop ring-down technique is proposed in this paper. In the fiber loop, a U-bent single-mode-fiber structure coated with magnetic fluid(MF) serves as the sensing head, and an erbium-doped fiber amplifier(EDFA) is introduced to compensate for the intrinsic loss of the cavity. The ring-down time of the system varies with the change of applied magnetic field due to the tunable absorption coefficient and refractive index of the MF. Therefore, measurement of the magnetic field can be realized by monitoring the ringdown time. The experimental results show that the performance of the system is extremely dependent on the interrogation wavelength, because both the gain of the EDFA and the loss of the sensing head are wavelength dependent.We found that at the optimal wavelength, the ratio of the gain to loss attained its maximum. The sensing system was experimentally demonstrated and a sensitivity of-0.5951 μs∕Oe was achieved.
基金partially supported by the Natural Science Foundation of Tianjin under grant 13JCYBJC16100the National Natural Science Foundation of China under grants 61107035 and 61378043+1 种基金the National Key Scientific Instrument and Equipment Development Project of China under grant 2013YQ03091502the National Basic Research Program of China(973 Program)under grant 2014CB340104
文摘In this paper, Er/Yb co-doped fiber amplifiers(EYDFAs) with an Yb-band fiber Bragg grating(FBG) at the pump end to improve the performance of the amplifier is systematically studied. The influence of the reflectivity and center wavelength of the FBG along with the gain-fiber length on the performance of an EYDFA are numerically analyzed. The results show that the wavelength of the FBG has critical influence on the efficiency of the EYDFA,whereas the requirement to its reflectivity is relaxed. It is an effective and promising way to improve the efficiency of a high-power pumped EYDFA by introducing a suitable Yb-band FBG at the pump end. Based on the analysis of the underlying principles, suggestions for the practical design and possible further improvement strategies are also proposed.
基金the National Natural Science Foundation of China(Nos.61904067,61805108,61575084,and 62075088)Science and Technology Projects in Guangzhou(No.202102020758)+3 种基金Guangdong Basic and Applied Basic Research Foundation(No.2020A1515011498)Science&Technology Project of Guangzhou City(No.201807010077)Key-Area Research and Development Program of Guangdong Province(No.2019B010934001)the Fundamental Research Funds for the Central Universities(Nos.21621405 and 21620328).
文摘Silver nanowire(AgNW)based transparent electrode(TE)plays a pivotal role in optoelectronics where TE is generally required to have fine pattern and high performance.Despite the rapid technological advances in either welding or patterning of AgNWs,there are few studies that combine the two processes in a simple and practical manner.Here,aiming to fabricate high-performance patterned AgNW TE,we develop a simplified photolithography that enables both plasmonic nanowelding with low-level UV exposure(20 mW/cm^(2))and high-resolution micropatterning without photoresist and etching process by conjugating AgNW with diphenyliodonium nitrate(DPIN)and UV-curable cellulose.The cellulose as a binder can effectively enhance plasmonic heating,adhesion,and stability,while the photosensitive DPIN,capable of modulating surface atom diffusion,can boost the plasmonic welding at AgNW junction and induce patterning in AgNW network with Plateau-Rayleigh instability.The fabricated AgNW TE has high figure of merit of up to 1,000(3.7Ω/sq at 90%transmittance)and minimal pattern size down to 3µm,along with superior robustness.Finally,a flexible smart window with high performance is demonstrated using the patterned and welded AgNW TEs,verifying the applicability of the simplified photolithography technique to optoelectronic devices.
基金supported by the National Natural Science Foundation of China (Grant Nos. 62175094, 61904067, 61805108, and 62075088)Basic and Applied Basic Research Foundation of Guangdong Province (Grant Nos. 2022A1515011671, 2022A1515010272, and 2020A1515011498)+2 种基金Basic and Applied Basic Research Foundation of Guangzhou (Grant No. 202102020758)Science and Technology R&D Project of Shenzhen (Grant Nos. JSGG20201102163800003, and JSGG20210713091806021)Fundamental Research Funds for the Central Universities (Grant Nos. 21621405, and 21620328)。
文摘Hyperbolic metamaterials(HMMs) are novel artificial materials that excite the surface plasmon resonance(SPR) because of their unique hyperbolic dispersion properties. Herein, to the best of our knowledge, we propose the first HMM-based fiber SPR(HMM-SPR) sensor for vector magnetic detection. By selecting the composite materials and structural parameters of the HMM dispersion management, HMM-SPR sensors can achieve a high refractive index sensitivity of 14.43 μm/RIU. Vector magnetic field detection was performed with the HMM-SPR sensor encapsulated with a magnetic fluid. Compared with other ferrofluidbased magnetic field fiber sensors, the proposed sensor shows pronounced advantages in intensity and direction sensitivity of 1.307 nm/Oe and 7.116 nm/°, respectively. The sensor design approach presented in this paper provides an excellent demonstration of HMM-SPR sensors in various applications.
基金The work is supported by the National Natural Science Foundation of China(Nos.61904067,62175094,61805108,and 62075088)Science and Technology Projects in Guangzhou(No.202102020758)+3 种基金Guangdong Basic and Applied Basic Research Foundation(No.2020A1515011498)Scientific and Technological Projection of Guangdong province(No.2020B1212060030)KeyArea Research and Development Program of Guangdong Province(No.2019B010934001)Fundamental Research Funds for the Central Universities(Nos.21621405 and 21620328).
文摘Patterned silver nanowire(AgNW)networks have been widely used as transparent electrodes in many optoelectrical devices.However,obvious patterning visibility and poor thermostability of AgNW are still limiting its practical application.Herein,we report self-assembled monolayer(SAM)modulated Plateau-Rayleigh instability(PRI)of AgNW,which allows invisible patterning and superior stability of the AgNW network.Two opposite effects of different SAMs on the PRI are identified:the alkanethiol SAMs activate surface atom diffusion while the mercaptobenzoheterocyclic(MBH)SAMs suppress the diffusion.The degradation temperature of the AgNWs can be therefore,for the first time,tuned in the range of 193-381℃,so that the AgNW network can be patterned via PRI with a tiny optical difference between the insulative and conductive regions,i.e.,patterning invisible.Besides,the MBH SAMs provide AgNW with excellent durability under thermal annealing and oxidation,which enhances the maximum heating temperature of the AgNW transparent heater by over 120℃.Beyond the micro-patterning,we consider that the developed SAM strategy can be extended to other metal nanowires for stability improvement and has huge potential in nanoengineering of one-dimensional metal materials.