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Hollow and filled fiber bragg gratings in nano-bore optical fibers
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作者 张永欣 梁生 +9 位作者 余倩卿 廉正刚 董梓年 王旋 林裕勤 邹郁祁 邢坤 梁柳雁 赵小艇 涂立静 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第7期279-285,共7页
To combine the technical functions and advantages of solid-core fiber Bragg gratings(FBGs) and hollow-core optical fibers(HCFs), the hollow and filled FBGs in nano-bore optical fibers(NBFs) with nano-bore in the GeO2-... To combine the technical functions and advantages of solid-core fiber Bragg gratings(FBGs) and hollow-core optical fibers(HCFs), the hollow and filled FBGs in nano-bore optical fibers(NBFs) with nano-bore in the GeO2-doped core are proposed.The fundamental mode field, effective mode index, and confinement loss of NBF with 50 nm–7 μm-diameter hollow and filled nano-bore are numerically investigated by the finite element method.The reflected spectra of FBGs in NBFs are obtained by the transmission matrix method.The hollow FBGs in NBFs can be acheived with ~5% power fraction in the bore and the ~0.9 reflectivity when bore diameter is less than 3 μm.The filled FBGs can be realized with~1% power fraction and 0.98 reflectivity with different fillings including o-xylene, trichloroethylene, and chloroform for 800-nm bore diameter.The feasibility of the index sensing by our proposed NBF FBG is also analyzed and discussed.The experimental fabrication of hollow and filled FBGs are discussed and can be achieved by current techniques.The aim of this work is to establish a principle prototype for investigating the HCFs and solid-core FBGs-based fiber-optic platforms,which are useful for applications such as the simultaneous chemical and physical sensing at the same position. 展开更多
关键词 nano-bore OPTICAL FIBER FIBER Bragg grating(FBG) hollow-core OPTICAL fiber(HCF) FIBER optics
Laser Wavelength Estimation Method Based on a High-Birefringence Fiber Loop Mirror
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作者 Ricardo I.ALVAREZ-TAMAYO Patricia PRIETO-CORTES +3 位作者 Manuel DURAN-SANCHEZ Baldemar IBARRA-ESCAMILLA Antonio BARCELATA-PINZON Evgeny A.KUZIN 《光子传感器:英文版》 EI CAS CSCD 2019年第1期89-96,共8页
A simple method for the estimation of the wavelength of a fiber laser system is proposed. The method is based on the use of a high-birefringence-fiber loop mirror(HBFLM).The HBFLM exhibits a periodic transmission/refl... A simple method for the estimation of the wavelength of a fiber laser system is proposed. The method is based on the use of a high-birefringence-fiber loop mirror(HBFLM).The HBFLM exhibits a periodic transmission/reflection spectrum whose spectral characteristics are determined by the length and temperature of the high-birefringence fiber(HBF).Then,by the previous characterization of the HBFLM spectral transmission response,the central wavelength of the generated laser line can be estimated.By using a photodetector,the wav.elength of the laser line is estimated during an HBF temperature scanning by measuring the temperature at which the maximum transmitted power of the HBFLM is reached.The proposed method is demonstrated in a linear cavity tunable Er/Yb fiber laser.This method is a reliable and low-cost alternative for laser wavelength determination in short wavelength ranges without the use of specialized and expensive equipment. 展开更多
关键词 WAVELENGTH meter FIBER LASERS FIBER optical loop MIRROR high-birefringence FIBER
Experimental and numerical investigation of mid-infrared laser in Pr3+-doped chalcogenide fiber
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作者 陈华 夏克伦 +4 位作者 刘自军 王训四 章向华 许银生 戴世勋 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第2期257-263,共7页
We report on a chalcogenide glass fiber doped with Pr3+ that can be used for commercialized 1.5-μm and 2-μm laser excitations by emitting broadband 3 μm–5.5 μm fluorescence, which is extruded into a preform and t... We report on a chalcogenide glass fiber doped with Pr3+ that can be used for commercialized 1.5-μm and 2-μm laser excitations by emitting broadband 3 μm–5.5 μm fluorescence, which is extruded into a preform and then drawn into a step-index fiber. The spectroscopic properties of the fiber and glass are reported, and the mid-infrared fiber lasers are also numerically investigated. Cascade lasing is employed to increase the inversion population of the upper laser level. The particle swarm approach is applied to optimize the fiber laser parameters. The output power can reach 1.28 W at 4.89-μm wavelength, with a pump power of 5 W, excitation wavelength at 2.04 μm, Pr3+ ion concentration at 4.22 × 1025 ions/m3,fiber length at 0.94 m, and fiber background loss at 3 dB/m. 展开更多
关键词 MID-INFRARED FIBER LASER CHALCOGENIDE GLASS FIBER rare earth DOPED GLASS FIBER LASER modelling
Fabrication of kW-level chirped and tilted fiber Bragg gratings and filtering of stimulated Raman scattering in high-power CW oscillators
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作者 Kerong Jiao Jian Shu +3 位作者 Hua Shen Zhiwen Guan Feiyan Yang Rihong Zhu 《高功率激光科学与工程:英文版》 CAS CSCD 2019年第2期76-82,共7页
Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,afte... Suppression of stimulated Raman scattering(SRS)by means of chirped and tilted fiber Bragg gratings(CTFBGs)has become a key topic.However,research on high-power systems is still lacking due to two problems.Firstly,after the inscription,there are a large number of hydroxyl compounds and hydrogen molecules in CTFBGs that cause significant heating due to their strong infrared absorption.Secondly,CTFBGs can couple Stokes light from the core to the cladding and the coating,which causes serious heating in the coating of the CTFBG.Aimed at overcoming these bottlenecks,a process that combines constant-low-temperature and variable-high-temperature annealing is used to reduce the thermal slope of the CTFBG.Also,a segmented-corrosion cladding power stripping technology is used on the CTFBG to remove the Stokes light which is coupled to the cladding,which solves the problem of overheating in the coating of the CTFBG.Thereby,a CTFBG with both a kilowatt-level power-carrying load and the ability to suppress SRS in a fiber laser has been developed.Further,we establish a kW-level CW oscillator to test the CTFBG.Experimental results demonstrate that the power-carrying load of the CTFBG is close to 1 kW,the thermal slope is lower than 0.015 ℃/W,and the SRS suppression ratio is nearly 23 dB. 展开更多
关键词 CHIRPED and tilted FIBER BRAGG GRATINGS FIBER optics components HIGH-POWER FIBER laser stimulated Raman scattering
Recent developments in novel silica-based optical fibers
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作者 Ting-yun WANG Fu-fei PANG +3 位作者 Su-juan HUANG Jian-xiang WEN Huan-huan LIU Li-bo YUAN 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2019年第4期481-489,共9页
We have summarized our recent work in the area of novel silica-based optical fibers, which can be classified into two types: silica optical fiber doped with special elements including Bi, Al, and Ce, and micro-structu... We have summarized our recent work in the area of novel silica-based optical fibers, which can be classified into two types: silica optical fiber doped with special elements including Bi, Al, and Ce, and micro-structured multi-core fibers. For element-doped optical fiber, the Bi/Al co-doped silica fibers could exhibit a fluorescence spectrum covering the wavelength range between 1000 and 1400 nm with a full width at half maximum(FWHM) of about 150 nm, which enables its use in fiber amplifiers and laser systems. The Ce-doped fiber’s center wavelengths of excitation and emission are about 340 and 430 nm, respectively. The sapphire-derived fiber(SDF) with high alumina dopant concentration in the core can form mullite through heating and cooling with arc-discharge treatment. This SDF can be further developed for an intrinsic Fabry-Perot interferometric that can withstand 1200 ℃, which allows it to be used in high-temperature sensing applications. Owing to the strong evanescent field, microstructured multi-core fiber can be used in a wide range of applications in biological fiber optic sensing, chemical measurement, and interference-related devices. Coaxial-core optical fiber is another novel kind of silica-based optical fiber that has two coaxial waveguide cores and can be used for optical trapping and micro-particle manipulation by generating a highly focused conical optical field. The recent developments of these novel fibers are discussed. 展开更多
关键词 Optical FIBER FIBER OPTIC DEVICE Silica-based SPECIAL FIBER
Mechanical properties of steel, glass, and hybrid fiber reinforced reactive powder concrete
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作者 Atheer H. M. ALGBURI M. Neaz SHEIKH Muhammad N. S. HADI 《结构与土木工程前沿:英文版》 EI CSCD 2019年第4期998-1006,共9页
This study examines the properties of fiber-reinforced reactive powder concrete (FR-RPC). Steel fibers, glass fibers, and steel-glass hybrid fibers were used to prepare the FR-RPC. The non-fibrous reactive powder conc... This study examines the properties of fiber-reinforced reactive powder concrete (FR-RPC). Steel fibers, glass fibers, and steel-glass hybrid fibers were used to prepare the FR-RPC. The non-fibrous reactive powder concrete (NF-RPC) was prepared as a reference mix. The proportion of fibers by volume for all FR-RPC mixes was 1.5%. Steel fibers of 13 mm length and 0.2 mm diameter were used to prepare the steel fiber-reinforced RPC (SFR-RPC). Glass fibers of 13 mm length and 1.3 mm diameter were used to prepare the glass fiber-reinforced RPC (GFR-RPC). The hybrid fiber-reinforced RPC (HFR-RPC) was prepared by mixing 0.9% steel fibers and 0.6% glass fibers. Compressive strength, axial load-axial deformation behavior, modulus of elasticity, indirect tensile strength, and shear strength of the RPC mixes were investigated. The results showed that SFR-RPC achieved higher compressive strength, indirect tensile strength and shear strength than NF-RPC, GFR-RPC, and HFR-RPC. Although the compressive strengths of GFR-RPC and HFR-RPC were slightly lower than the compressive strength of NF-RPC, the shear strengths of GFR-RPC and HFR-RPC were higher than that of NF-RPC. 展开更多
关键词 REACTIVE POWDER concrete steel FIBER GLASS FIBER hybrid FIBER
Mitigation of stimulated Raman scattering in kilowatt-level diode-pumped fiber amplifiers with chirped and tilted fiber Bragg gratings
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作者 Meng Wang Le Liu +2 位作者 Zefeng Wang Xiaoming Xi Xiaojun Xu 《高功率激光科学与工程:英文版》 CAS CSCD 2019年第1期128-133,共6页
The average power of diode-pumped fiber lasers has been developed deeply into the kW regime in the past years.However,stimulated Raman scattering(SRS)is still a major factor limiting the further power scaling.Here,we ... The average power of diode-pumped fiber lasers has been developed deeply into the kW regime in the past years.However,stimulated Raman scattering(SRS)is still a major factor limiting the further power scaling.Here,we have demonstrated the mitigation of SRS in kilowatt-level diode-pumped fiber amplifiers using a chirped and tilted fiber Bragg grating(CTFBG)for the first time.The CTFBG is designed and inscribed in large-mode-area(LMA)fibers,matching with the operating wavelength of the fiber amplifier.With the CTFBG inserted between the seed laser and the amplifier stage,an SRS suppression ratio of~10 dB is achieved in spectrum at the maximum output laser power of 2.35 kW,and there is no reduction in laser slope efficiency and degradation in beam quality.This work proves the feasibility and practicability of CTFBGs for SRS suppression in high-power fiber lasers,which is very useful for the further power scaling. 展开更多
关键词 FIBER BRAGG GRATINGS FIBER lasers high power stimulated Raman scattering
A brief review on natural fiber used as a replacement of synthetic fiber in polymer composites 预览
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作者 Fatin I. Mahir Kamrun N. Keya +2 位作者 Bijoyee Sarker Khandakar M. Nahiun Ruhul A. Khan 《材料工程研究(英文)》 2019年第2期86-97,共12页
The use of composites in different sectors has become inevitable due to the enhancement in properties, reduction in the manufacturing cost and suitability to several applications. Among different classifications, poly... The use of composites in different sectors has become inevitable due to the enhancement in properties, reduction in the manufacturing cost and suitability to several applications. Among different classifications, polymeric composites are mainly focused on their use as structural components and the selection and composition of reinforcement play a vital role in determining the characteristics of the composite. Although composites are developed with man-made reinforcement in the beginning stage, in the present situation, natural reinforcements have proved excellent results in terms of properties. Hence, nowadays researches are mainly focused on the use of different natural fibers in different forms as reinforcements in polymeric composite. This work presents a brief overview on the properties of natural fiber and natural fiber reinforced composites which is an emerging area in polymer science. Interests in natural fiber is reasonable due to the advantages of these materials compared to others, such as synthetic fiber composites, including low environmental impact and low cost and support their potential to be used. Moreover, the disadvantage of the synthetic and fiber-glass as reinforcement, the use of natural fiber reinforced composite gained the attention of the young scientists, researchers, and engineers and are being exploited as a replacement for the conventional fiber such as glass, aramid, carbon etc. Natural fibers have been proven alternative to synthetic fiber in transportation such as automobiles, railway coaches and aerospace, military, building, packaging, consumer products and construction industries for ceiling paneling, partition boards etc. However, in development of these composites, some drawbacks have also emerged. In this paper, it has been tried to overview all of this together. 展开更多
关键词 natural FIBER SYNTHETIC FIBER polymer COMPOSITE COMPOSITE and bio-degradable
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Bio Caryota Fiber Reinforced Polymer Composites: Mechanical Properties and Vibration Behavior Analysis
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作者 Kayaroganam Palanikumar Vijayakumar Subbiah 《仿生工程学报:英文版》 SCIE EI CSCD 2019年第3期480-491,共12页
Polymer composites reinforced with the biofibers are found to have improved applications in many fields and also they can reduce the environmental effect. In this work, caryota-a new natural fiber for polymer composit... Polymer composites reinforced with the biofibers are found to have improved applications in many fields and also they can reduce the environmental effect. In this work, caryota-a new natural fiber for polymer composites is fabricated and their tensile, flexural and impact properties are estimated to be used in economical and lightweight load carrying structures. Laminates at different weight fraction (wt%) of 10 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt% and 45 wt% are manufactured using a compression molding technique. Results asserted that the unidirectional arrangement having 40 wt% fiber posses good properties. Also the dynamic characteristics such as natural frequency and damping study are carried out for different wt% of unidirectional caryota fiber reinforced composite laminates by ex? perimental modal analysis. From this study, it has been asserted that by using the caryota fiber reinforced polyester composites, the traditional synthetic fiber can be replaced especially in automobile sector. If the caryota fiber reinforced composite material is applied properly, then its application fields will be improved. 展开更多
关键词 natural FIBER caryota FIBER REINFORCEMENTS polymer-matrix COMPOSITES (PMCs) mechanical properties VIBRATION analysis
Study on Glass Fiber Dispersion Technology in SiO2 Aerogel-glass Fiber Composite Insulation Materials 预览
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作者 WANG Haimei SUN Xiaofei LI Hongxia 《中国耐火材料:英文版》 CAS 2019年第1期32-36,共5页
In order to improve the mechanical properties of SiO2 aerogel-glass fiber composites, effects of different solvents(cyclohexane, n-hexane, ethanol, acetone) and different dispersing modes(planetary ball milling, ultra... In order to improve the mechanical properties of SiO2 aerogel-glass fiber composites, effects of different solvents(cyclohexane, n-hexane, ethanol, acetone) and different dispersing modes(planetary ball milling, ultrasonic dispersion and mechanical stirring) and dispersing duration(10-40 min) on the dispersion of chopped alkali-free glass fiber bundles were studied to determine the best dispersion process. On this basis, the materials were batched according to the mass fraction of SiO2 aerogel powder to chopped alkali free glass fiber bundles of 90:10, and a certain amount of zinc oxide light-screening agent and phenolic resin binder were added. SiO2 aerogel glass fiber composite specimens were prepared by direct adding chopped alkali free glass fiber bundles and pre-dispersed chopped alkali free glass fiber bundles, respectively. The cold crushing strength and the thermal conductivity at different surface temperatures(300, 400, 500 and 600 ℃, respectively)of the specimens were measured. The results show that:(1) the optimum dispersion process of chopped alkali-free glass fiber bundles is using ethanol as solvent and mechanical stirring for 30 min;(2) pre-dispersion of chopped alkali-free glass fiber bundles has little effect on the thermal conductivity of SiO2 aerogel-glass fiber composites but can improve the cold crushing strength. 展开更多
关键词 silicon aerogel-glass insulating materials alkali-free GLASS FIBER FIBER REINFORCEMENT DISPERSION
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Feasibility assessment of phenotyping cotton fiber maturity using infrared spectroscopy and algorithms for genotyping analyses 预览
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作者 KIM Hee Jin LIU Yongliang +1 位作者 FANG David D. DELHOM Christopher D. 《棉花研究(英文)》 2019年第1期44-55,共12页
Background:Cotton fiber maturity is an important property that partially determines the processing and performance of cotton.Due to difficulties of obtaining fiber maturity values accurately from every plant of a gene... Background:Cotton fiber maturity is an important property that partially determines the processing and performance of cotton.Due to difficulties of obtaining fiber maturity values accurately from every plant of a genetic population,cotton geneticists often use micronaire(MIC) and/or lint percentage for classifying immature phenotypes from mature fiber phenotyp es although they are complex fiber traits.The recent development of an algorithm for determining cotton fiber maturity(MIR)from Fourier transform infrared(FT-IR)spectra explores a novel way to measure fiber maturity efficiently and accurately.However,the algorithm has not been tested with a genetic population consisting of a large number of progeny pla,nts.Results:The merits and limits of the MIC-or lint percentage-bas ed phenotyping method were demonstrated by comparing the observed phenotypes with the predicted phenotypes based on their DNA marker genotypes in a genetic population consisting of 708 F2 plants with various fiber maturity.The observed MIC-based fiber phenotypes matched to the predicted phenotypes better than the observed lint percenta ge-based fiber phenotypes.The lint percentage was obtained from each of F2 plants,whereas the MIC values were unable to be obtained from the entire population since certain F2 plants produced insufficient fiber mass for their measurements.To test the feasibiility of cotton fiber infrared maturity(MIR)as a viable phenotyping tool for genetic analyses,we me asured FT-IR spectra from the second population composed of 80 F2 plants with various fiber maturities,determined MIR values using the algorithms,and compared them with their genotypes in addition to other fiber phenotypes.The results showed that MIR values were successfully obtained from each of the F2 plants,and the observed MIR-based phenotypes fit well to the predicted phenotypes based on their DNA marker genotypes as well as the observed phenotypes based on a combination of MIC and lint percentage.Conclusions:The M,R value obtained from FT-IR spectra of c 展开更多
关键词 Attenuated total reflection Fourier transform infrared spectroscopy Cotton FIBER MATURITY CRYSTALLINITY IMMATURE FIBER (im) mutant
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Supercontinuum generation of highly nonlinear fibers pumped by 1.57-μm laser soliton
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作者 樊松涛 张颜艳 +3 位作者 闫露露 郭文阁 张首刚 姜海峰 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第6期199-203,共5页
Highly nonlinear fibers(HNLFs) are crucial components for supercontinuum(SC) generation with laser solution.However, it is difficult to exactly estimate the structure of produced SC according to material parameters. T... Highly nonlinear fibers(HNLFs) are crucial components for supercontinuum(SC) generation with laser solution.However, it is difficult to exactly estimate the structure of produced SC according to material parameters. To give a guideline for choosing and using HNLFs for erbium-fiber-based optical applications, we demonstrate SC generation in five types of HNLFs pumped by 1.57-μm laser solitons. All five fibers output a SC exceeding 1000 nm. Three different SC formation processes were observed in the experiment. By comparing optical parameters of these fibers, we find the zero dispersion wavelength(ZDW) of fiber has an important influence on the SC structure and energy distribution for a given pump source. 展开更多
关键词 highly nonlinear FIBER erbium-fiber laser SUPERCONTINUUM generation
Transverse Compressive Properties of Carbon/Glass Hybrid Thermoplastic Composite Rods 预览
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作者 Kimiyoshi Naito Chiemi Nagai Yoshihisa Tanaka 《物理科学与应用:英文版》 2019年第1期25-33,共9页
Novel carbon/glass hybrid thermoplastic composite rods having different carbon/glass ratios (24K1P,24K2P,and 24K3P) are commercially fabricated.The transverse compressive properties of these three hybrid rods were inv... Novel carbon/glass hybrid thermoplastic composite rods having different carbon/glass ratios (24K1P,24K2P,and 24K3P) are commercially fabricated.The transverse compressive properties of these three hybrid rods were investigated.The load-displacement curve showed large nonlinear behavior and a complicated shape.In the initial stage,the load gradually increased by increasing the deformation.In the second stage,the load-displacement relation was almost linearly proportional to the displacement (stable deformation region).Subsequently,the slope decreased slightly,before the load-displacement curve showed a clear slope increase as the deformation proceeded.The fracture behavior of the hybrid rods was examined using a digital microscope.The observed fracture paths formed almost straight lines running through the loading point,the center of the cross section of carbon fiber bundles/thermoplastic epoxy,as well as the interface between the glass fiber bundles/thermoplastic epoxy and the carbon fiber bundles/thermoplastic epoxy. 展开更多
关键词 CARBON FIBER GLASS FIBER thermoplastic epoxy HYBRID TRANSVERSE COMPRESSIVE properties
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Thulium-Doped Fiber Amplifier for Blue Light Signal Amplification 预览
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作者 Muhammad Hanif Ahmed Khan Khushik Chun Jiang 《中国通信:英文版》 SCIE CSCD 2019年第5期181-188,共8页
Fluoride-based thulium-doped visible light fiber amplifier(TmVLFA), which can be used to amplify the blue light signal for a visible light communication(VLC) system,is theoretically demonstrated for the first time acc... Fluoride-based thulium-doped visible light fiber amplifier(TmVLFA), which can be used to amplify the blue light signal for a visible light communication(VLC) system,is theoretically demonstrated for the first time according to the best of our knowledge. The transition rate equations and power propagation equations are solved to predict the dependence of the gain and noise figure on fiber parameters. The numerical results show that with the pump wavelength 1150 nm and pump power 800 mW, 2.75 m long thulium-doped fiber can amplify blue light(480 nm) signal up to 33.3 dB, and the noise figure is in the range from 3.0 to 3.5 dB. The model and numerical results encourage the use of fiber amplifier in VLC system for blue light amplification to extend the range of VLC. 展开更多
关键词 Tm-doped VISIBLE LIGHT FIBER AMPLIFIER VISIBLE LIGHT communication FIBER AMPLIFIER GAIN noise FIGURE
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Highly stable femtosecond pulse generation from a MXene Ti3C2Tx(T = F, O, or OH) mode-locked fiber laser
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作者 Jie Li Zilong Zhang +6 位作者 Lin Du Lili Miao Jun Yi Bin Huang Yanhong Zou Chujun Zhao SHUANGCHUN WEN 《光子学研究:英文版》 CSCD 2019年第3期260-264,共5页
Ultrafast fiber lasers are in great demand for various applications, such as optical communication, spectroscopy,biomedical diagnosis, and industrial fabrication. Here, we report the highly stable femtosecond pulse ge... Ultrafast fiber lasers are in great demand for various applications, such as optical communication, spectroscopy,biomedical diagnosis, and industrial fabrication. Here, we report the highly stable femtosecond pulse generation from a MXene mode-locked fiber laser. We have prepared the high-quality Ti3C2 Tx nanosheets via the etching method, and characterized their ultrafast dynamics and broadband nonlinear optical responses. The obvious intensity-and wavelength-dependent nonlinear responses have been observed and investigated. In addition, a highly stable femtosecond fiber laser with signal-to-noise ratio up to 70.7 dB and central wavelength of 1567.3 nm has been delivered. The study may provide some valuable design guidelines for the development of ultrafast, broadband nonlinear optical modulators, and open new avenues toward advanced photonic devices based on MXenes. 展开更多
关键词 Ultrafast FIBER lasers FEMTOSECOND pulse MXene Ti3C2Tx(T = F O or OH) MODE-LOCKED FIBER laser
Effects of dietary fiber content and different fiber-rich ingredients on endogenous loss of fat and fatty acids in growing pigs 预览
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作者 Yifan Chen Zhenyu Wang +5 位作者 Jian Ding Dongxu Ming Wenhui Wang Zhaoning Jiang Ling Liu Fenglai Wang 《畜牧与生物技术杂志:英文版》 SCIE CAS CSCD 2019年第3期745-758,共14页
Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and ingredients.Any factor which affected ELF may further affec... Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and ingredients.Any factor which affected ELF may further affect the digestibility of fat,including sources and concentrations of fat and fiber in the diet.There are some reports of determining the ELF using regression methods based on different levels of fat intake,while reports on effects of dietary fiber content and different fiber-rich ingredients in pig diets on ELF are very limited.Therefore,the objective of this study was to determine the effects of dietary fiber content and different fiber-rich ingredients on endogenous losses of fat and fatty acids at the end of ileum and throughout the entire intestinal tract in growing pigs.Methods: In Exp.1,the effect of fiber content on endogenous loss of fat was determined using six growing pigs(Duroc × Landrace × Yorkshire;27.6 ± 2.4 kg),fitted with a T-cannula at the end of ileum.The experimental design was a 6 × 6 complete Latin square design with six periods of feeding and six diets.The six experimental fat-free diets were formulated to include graded levels of neutral detergent fiber(NDF)(0,40,80,120,160 and 200 g/kg) and soybean hull(SH) was the only fiber source,providing 0,75,150,225,300 and 375 g/kg,respectively.Chromic oxide was included at4 g/kg in all diets as an indigestible marker.In Exp.2,six crossbred growing barrows(27.6 ± 1.6 kg) were used and the experimental design was the same as for Exp.1.The six fat-free diets were formulated to include six common fiber-rich ingredients and the concentration of NDF was 100 g/kg.The six fiber-rich ingredients were defatted rice bran(DRB),sugar beet pulp(SBP),rice hull(RH),corn germ meal(CGM),SH and wheat bran(WB) and they were fed at represented250,270,145,250,170 and 280 g/kg in the diet,respectively.Results: In Exp.1,the endogenous loss of fatty acids profile did not change as dietary NDF increased in growing pigs.The endogenous losses of fat,C16:0,C18: 展开更多
关键词 ENDOGENOUS LOSS FAT Fatty acids FIBER content Fiber-rich INGREDIENTS Growing pigs
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High-Sensitivity Temperature Sensor Based on Polarization Maintaining Fiber Sagnac Loop
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作者 Laipeng SHAO Junhui HU +3 位作者 Hanglin LU Jing DU Tianyin WU Yiping WANG 《光子传感器:英文版》 EI CAS CSCD 2019年第1期25-32,共8页
A high-sensitivity all-fiber temperature sensor based on a Sagnac interferometer is demonstrated by splicing a section of polarization maintaining fiber(PMF)between two sections of standard single mode fibers(SMFs).In... A high-sensitivity all-fiber temperature sensor based on a Sagnac interferometer is demonstrated by splicing a section of polarization maintaining fiber(PMF)between two sections of standard single mode fibers(SMFs).In this sensor,the SMF-PMF-SMF structure in the Sagnac loop is bent into a circle to enhance the sensitivity.The length and curvature of the PMF in the loop are investigated and can be optimized to further increase the temperature sensitivity of the sensor. Results show that the radius of the circle has an important effect upon temperature sensitivity due to the bend-induced birefringence variation of the PMF.The SMF-PMF-SMF structure bent into a circle with a radius of 30mm exhibits a high-sensitivity temperature of 1.73nm/℃.The sensor is provided with the advantages of easy fabrication,low-insertion loss,and high sensitivity,which may find potential applications in the field of high precision temperature measurement. 展开更多
关键词 Optical FIBER SENSOR POLARIZATION maintaining FIBER temperature SENSOR SAGNAC LOOP
Application of MZI Symmetrical Structure With Fiber Balls and Seven-Core Fiber in Microdisplacement Measurement
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作者 Hong LI Yanming SONG +1 位作者 Mingli DONG Lianqing ZHU 《光子传感器:英文版》 EI CAS CSCD 2019年第2期97-107,共11页
An optical fiber microdisplacement sensor based on symmetric Mach-Zehnder interferometer (MZI) with a seven-core fiber and two single-mode fiber balls is proposed. The rationality and manufacturing process of the MZI ... An optical fiber microdisplacement sensor based on symmetric Mach-Zehnder interferometer (MZI) with a seven-core fiber and two single-mode fiber balls is proposed. The rationality and manufacturing process of the MZI sensing structure are analyzed. The fabrication mechanism of the Mach-Zehnder sensor by CO2 laser is described in detail. Experimental results show that temperature sensitivities of the two dips are 98.65 pm/℃ and 89.72pm/℃, respectively. The microdisplacement sensitivities are 2017.71 pm/mm and 2457.92 pm/mm, respectively. The simultaneous measurement of temperature and microdisplacement is demonstrated based on the sensitive matrix. The proposed Mach-Zehnder interference sensor exhibits the advantages of compact structure, simple manufacturing process, and high reliability. 展开更多
关键词 Microdisplacement Mach-Zehnder interferometer FIBER ball SYMMETRICAL STRUCTURE seven-core FIBER
Tunable and switchable harmonic h-shaped pulse generation in a 3.03 km ultralong mode-locked thulium-doped fiber laser
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作者 Junqing Zhao Lei Li +3 位作者 Luming Zhao Dingyuan Tang Deyuan Shen Lei Su 《光子学研究:英文版》 CSCD 2019年第3期332-340,共9页
We experimentally demonstrated a type of tunable and switchable harmonic h-shaped pulse generation in a thulium-doped fiber(TDF) laser passively mode locked by using an ultralong nonlinear optical loop mirror.The tota... We experimentally demonstrated a type of tunable and switchable harmonic h-shaped pulse generation in a thulium-doped fiber(TDF) laser passively mode locked by using an ultralong nonlinear optical loop mirror.The total cavity length was ~3.03 km, the longest ever built for a TDF laser to our best knowledge, which resulted in an ultralarge anomalous dispersion over -200 ps~2 around the emission wavelength. The produced h-shaped pulse can operate either in a fundamental or in a high-order harmonic mode-locking(HML) state depending on pump power and intra-cavity polarization state(PS). The pulse duration, no matter of the operation state, was tunable with pump power. However, pulse breaking and self-organizing occurred, resulting in high-order HML,when the pump power increased above a threshold. At a fixed pump power, the order of HML was switchable from one to another by manipulating the PS. Switching from the 8 th up to the 48 th order of HML was achieved with a fixed pump power of ~4.15 W. Our results revealed the detailed evolution and switching characteristics of the HML and individual pulse envelope with respect to both the pump power and PS. We have also discussed in detail the mechanisms of both the h-shaped pulse generation and the switching of its HML. This contribution would be helpful for further in-depth study on the underlying dynamics of long-duration particular-envelope pulses with ultralarge anomalous dispersion and ultralong roundtrip time. 展开更多
关键词 ultralong MODE-LOCKED thulium-doped FIBER laser SWITCHABLE HARMONIC h-shaped pulse thulium-doped fiber(TDF)
Influence of Internal Stresses in Few-Mode Fiber on the Thermal Characteristics of Regenerated Gratings
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作者 Nurul Asha MOHD NAZAL Kok Sing LIM +2 位作者 Yen Sian LEE Muhammad Aizi MAT SALIM Harith AHMAD 《光子传感器:英文版》 EI CAS CSCD 2019年第2期162-169,共8页
The pre-treatment of few-mode fibers (FMFs) has been successfully done with CO2 laser The wavelength difference, AA between the two resonant wavelengths in the few-mode fiber Bragg grating (FMFBG) varies with temperat... The pre-treatment of few-mode fibers (FMFs) has been successfully done with CO2 laser The wavelength difference, AA between the two resonant wavelengths in the few-mode fiber Bragg grating (FMFBG) varies with temperature increment during the annealing process. The results show that the treated fibers with lower stresses have lower thermal sensitivity in △λ than that of non-treated fiber. However, the treated fibers produce FMFBGs with better thermal durability and regeneration ratio. It is conceived that the presence of those stresses in the pristine fiber is responsible for the high thermal sensitivity in △λ. The thennal relaxation of stresses and structural rearrangement during the thennal annealing process are responsible for the degradation of the strength and resilience of the regenerated grating. 展开更多
关键词 Regenerated FIBER BRAGG GRATING few-mode FIBER thermal stress relaxation CO2 laser annealing thennal RESILIENCE
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