A technique is used to enhance the pressure and temperature sensitivity of a fiber Bragg grating sensor.The grating is packaged by using polymer jacket,which exhibits no significant chirp due to the adoption of the sp...A technique is used to enhance the pressure and temperature sensitivity of a fiber Bragg grating sensor.The grating is packaged by using polymer jacket,which exhibits no significant chirp due to the adoption of the special technique.The measured pressure and temperature sensitivity of the structured grating is 6.28×10^(-5)/MPa and5.18×10^(-5)/℃.The wavelength shift due to pressure and temperature can be enhanced about 31.5 times for pressure and 7.7 times for temperature.展开更多
An 800 nm band fiber Bragg grating sensing interrogation system using tilted FBG as the core wavelength division compo- nent is presented. A charge coupled device (CCD) linear array is put on the focal plane of the le...An 800 nm band fiber Bragg grating sensing interrogation system using tilted FBG as the core wavelength division compo- nent is presented. A charge coupled device (CCD) linear array is put on the focal plane of the lens to detect the light. TFBG is used to tap light out of the fiber core to fiber cladding. The sensing wavelength is 795 to 830 nm, with accuracy of 20 pm and scan speed 100Hz. Using FBG sensor, we achieve the temperature sensitivity of 1.8 ℃ and strain sensitivity of 18 με.展开更多
The general principles and realizations of FBG wavelength tuning with elastic beams are proposed and demonstrated.Theories and experiments show that when displacement at the center point of simple beams,deflection of ...The general principles and realizations of FBG wavelength tuning with elastic beams are proposed and demonstrated.Theories and experiments show that when displacement at the center point of simple beams,deflection of cantilever beams and torsion strain of torsion beams are relatively small,Bragg wavelength shifts of sensing FBGs have linear relationship with applied external stress,lateral displacement,torque and torsional angles,respectively.The experimental results indicate that the curvature sensitivity of the simple beam is 1.65 nm/m-1,the displacement sensitivity of the equivalent-strain cantilever beam is 4.4 cm/kg and the torque and torsional angle sensitivities of the torsion beam are 6.27 nm/Nm and 0.086 7 nm/degree,respectively.展开更多
A novel Yb3+-doped double-clad silica fibre with rectangular inner cladding was designed and developed by using the modified chemical vapour deposition process, solution-doping and optical machining all together. The ...A novel Yb3+-doped double-clad silica fibre with rectangular inner cladding was designed and developed by using the modified chemical vapour deposition process, solution-doping and optical machining all together. The dimensions of the inner cladding are 100 × 70 μm, and Yb^(3+)-doped concentration in the core is about 0.24 wt. %. The operation of the fibre laser pumped by inner cladding is reported. The threshold of the laser is 34mW.When the pump power launched is 141mW, the laser output is 84mW at the wavelength 1075.6nm, and the slope efficiency is 77%.展开更多
PbS quantum dots were prepared in the aqueous medium from readily available precursors. The shape of the particles isapproximately spherical, and the average particle size observed from HRTEM image was 7-8 nm. We appl...PbS quantum dots were prepared in the aqueous medium from readily available precursors. The shape of the particles isapproximately spherical, and the average particle size observed from HRTEM image was 7-8 nm. We applied PbS quantumdots and PMMA polymer to fabricate PbS quantum dots-PMMA composites, and investigate the photoluminescence PbSquantum dots in PMMA matrix with different mass ratio. PbS quantum dots in PMMA matrix have broad emission be-tween 900 nm and 1 500 nm and photoluminescence peak at 1 179 nm. Additionally, the photoluminescence intensityincreases with increasing the dopant concentration. PbS quantum dots-PMMA polymer composites can be potentially usedfor polymer optical fiber and electroluminescence (EL) in optical communication.展开更多
Starting from our definition of apodization profile functions,we discover the optimal profiles and the characteristics of defined apodization functions in sidelobe suppression.It is shown by numerical analysis that th...Starting from our definition of apodization profile functions,we discover the optimal profiles and the characteristics of defined apodization functions in sidelobe suppression.It is shown by numerical analysis that the optimal grating length is 45 mm to compensate for dispersion induced by 100 km fibres and the smoothness of the ripples in time-delay characteristics is related to the defined parameters.展开更多
A novel four-wavelength all-fiber laser based on fiber Bragg gratings is presented.The four wavelengths are 1555.8,1556.6,1557.4 and 1558.2 nm,respectively.Each output laser is<0.3 nm in line-width and>1 mW in p...A novel four-wavelength all-fiber laser based on fiber Bragg gratings is presented.The four wavelengths are 1555.8,1556.6,1557.4 and 1558.2 nm,respectively.Each output laser is<0.3 nm in line-width and>1 mW in power.The suppression ratio between adjacent wavelengths is>30 dB.The laser was applied in a wavelength division multiplexing(WDM)system and the 100 km transmission of 1.2 Gb/s nonreturn-to-zero code,1.2 Gb/s return-to-zero code,2.5 GHz analogue signal and 5 GHz analogue signal was realized with it.展开更多
乳腺增生(hyperplasia of mammary gland,HMG)是由内分泌激素紊乱导致的一种增生性疾病,发病趋势呈年轻化、上升化,并有癌变风险,严重危害女性健康,因此对HMG的防治越来越重视。随着中医药的发展,许多学者发现中成药在治疗内分泌紊乱方...乳腺增生(hyperplasia of mammary gland,HMG)是由内分泌激素紊乱导致的一种增生性疾病,发病趋势呈年轻化、上升化,并有癌变风险,严重危害女性健康,因此对HMG的防治越来越重视。随着中医药的发展,许多学者发现中成药在治疗内分泌紊乱方面有着独特优势和巨大潜力,尤其以具有活血散结作用的小金丸、消癥丸等已是临床常用治疗HMG的中成药,具有多靶点调控、疗效显著、副作用小、便于携带和服用的优点。有临床研究发现中成药联合用药后不仅可以提高疗效、缓解增生及疼痛等症状,还可降低西药的毒副作用,因此使用中成药及联合用药逐渐成为了临床治疗HMG的常用手段。在查阅了相关的药理及临床研究文献基础上,以活血散结类中成药和联合用药2个方面,从调节体内激素及受体水平、促进细胞凋亡、抑制新血管形成、改善血液流变学、增强免疫力、提高抗氧化能力等角度进行综述,深入阐述其作用机制,并且针对其现状提出不足之处和有待解决的问题,为活血散结类中成药及联合用药抗HMG的进一步研究和临床应用提供理论依据。展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.69879001.
文摘A technique is used to enhance the pressure and temperature sensitivity of a fiber Bragg grating sensor.The grating is packaged by using polymer jacket,which exhibits no significant chirp due to the adoption of the special technique.The measured pressure and temperature sensitivity of the structured grating is 6.28×10^(-5)/MPa and5.18×10^(-5)/℃.The wavelength shift due to pressure and temperature can be enhanced about 31.5 times for pressure and 7.7 times for temperature.
基金National Nature Science Foundation ofChina(60577018),the 863 National High Technology Prograrmof china (Grant No.2006AA01Z217),and the open Projectfoudation of key laboratory of Opto-eletronic Infr mation Scienceand Technology luinistry of Eolucation in Nankai university
文摘An 800 nm band fiber Bragg grating sensing interrogation system using tilted FBG as the core wavelength division compo- nent is presented. A charge coupled device (CCD) linear array is put on the focal plane of the lens to detect the light. TFBG is used to tap light out of the fiber core to fiber cladding. The sensing wavelength is 795 to 830 nm, with accuracy of 20 pm and scan speed 100Hz. Using FBG sensor, we achieve the temperature sensitivity of 1.8 ℃ and strain sensitivity of 18 με.
文摘The general principles and realizations of FBG wavelength tuning with elastic beams are proposed and demonstrated.Theories and experiments show that when displacement at the center point of simple beams,deflection of cantilever beams and torsion strain of torsion beams are relatively small,Bragg wavelength shifts of sensing FBGs have linear relationship with applied external stress,lateral displacement,torque and torsional angles,respectively.The experimental results indicate that the curvature sensitivity of the simple beam is 1.65 nm/m-1,the displacement sensitivity of the equivalent-strain cantilever beam is 4.4 cm/kg and the torque and torsional angle sensitivities of the torsion beam are 6.27 nm/Nm and 0.086 7 nm/degree,respectively.
基金Supported by the National Natural Science Foundation of China under Grant No.69877006Tianjin Natural Science Foundation(003600911)。
文摘A novel Yb3+-doped double-clad silica fibre with rectangular inner cladding was designed and developed by using the modified chemical vapour deposition process, solution-doping and optical machining all together. The dimensions of the inner cladding are 100 × 70 μm, and Yb^(3+)-doped concentration in the core is about 0.24 wt. %. The operation of the fibre laser pumped by inner cladding is reported. The threshold of the laser is 34mW.When the pump power launched is 141mW, the laser output is 84mW at the wavelength 1075.6nm, and the slope efficiency is 77%.
基金This work was supported by the National Key Basic ResearchDevelopment Program of China (Grant 2003CB314906)+1 种基金the Na-tional Natural Science Foundation of China (Grant 10674074)the Natural Science Foundation of Tianjin (Grant07JCYBJC06400)
文摘PbS quantum dots were prepared in the aqueous medium from readily available precursors. The shape of the particles isapproximately spherical, and the average particle size observed from HRTEM image was 7-8 nm. We applied PbS quantumdots and PMMA polymer to fabricate PbS quantum dots-PMMA composites, and investigate the photoluminescence PbSquantum dots in PMMA matrix with different mass ratio. PbS quantum dots in PMMA matrix have broad emission be-tween 900 nm and 1 500 nm and photoluminescence peak at 1 179 nm. Additionally, the photoluminescence intensityincreases with increasing the dopant concentration. PbS quantum dots-PMMA polymer composites can be potentially usedfor polymer optical fiber and electroluminescence (EL) in optical communication.
基金Supported by 863 National High Technology Research Plan(863-307-15)Tianjin Natural Science Foundation(003600811)China Postdoctoral Science Foundation and Huawei Scientific Research Foundation.
文摘Starting from our definition of apodization profile functions,we discover the optimal profiles and the characteristics of defined apodization functions in sidelobe suppression.It is shown by numerical analysis that the optimal grating length is 45 mm to compensate for dispersion induced by 100 km fibres and the smoothness of the ripples in time-delay characteristics is related to the defined parameters.
基金Supported by the National‘863’high technology project(863-307-15-5(11)).
文摘A novel four-wavelength all-fiber laser based on fiber Bragg gratings is presented.The four wavelengths are 1555.8,1556.6,1557.4 and 1558.2 nm,respectively.Each output laser is<0.3 nm in line-width and>1 mW in power.The suppression ratio between adjacent wavelengths is>30 dB.The laser was applied in a wavelength division multiplexing(WDM)system and the 100 km transmission of 1.2 Gb/s nonreturn-to-zero code,1.2 Gb/s return-to-zero code,2.5 GHz analogue signal and 5 GHz analogue signal was realized with it.
文摘乳腺增生(hyperplasia of mammary gland,HMG)是由内分泌激素紊乱导致的一种增生性疾病,发病趋势呈年轻化、上升化,并有癌变风险,严重危害女性健康,因此对HMG的防治越来越重视。随着中医药的发展,许多学者发现中成药在治疗内分泌紊乱方面有着独特优势和巨大潜力,尤其以具有活血散结作用的小金丸、消癥丸等已是临床常用治疗HMG的中成药,具有多靶点调控、疗效显著、副作用小、便于携带和服用的优点。有临床研究发现中成药联合用药后不仅可以提高疗效、缓解增生及疼痛等症状,还可降低西药的毒副作用,因此使用中成药及联合用药逐渐成为了临床治疗HMG的常用手段。在查阅了相关的药理及临床研究文献基础上,以活血散结类中成药和联合用药2个方面,从调节体内激素及受体水平、促进细胞凋亡、抑制新血管形成、改善血液流变学、增强免疫力、提高抗氧化能力等角度进行综述,深入阐述其作用机制,并且针对其现状提出不足之处和有待解决的问题,为活血散结类中成药及联合用药抗HMG的进一步研究和临床应用提供理论依据。
