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Temperature dependence of radiation-induced attenuation of optical fibers

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Chinese Optics Letters 2012年第11期10卷 25-27页

作者：宋镜明郭建华王学勤金靖 School of Instrumentation Science and Opto-electronics Engineering Beihang University

We investigate the temperature dependence of radiation-induced attenuation （RIA） at 1310 nm for a Ge/P co-doped fiber after a steady-state γ-ray irradiation. A V irradiation facility 6^60Co source is used to irradiate the fiber at a dose rate of 0.5 Gy/min, satisfying a total dose of 100 Gy. The test temperature ranges from -40 to 60 ℃ by 20 ℃, and the RIA of the fiber is obtained using a power measuring device. The experimental result demonstrates that RIA exhibits a steady, monotonic, and remarkable temperature dependence after approximately 48 h of accelerated annealing at 70 ℃. The optical fiber irradiated with a high dose and annealed sufficiently can be used as a temperature sensor.

关键词： Irradiation optical fibers

Ultra-broad near-infrared emission of Bi-doped SiO_2 Al_2O_3 GeO_2 optical fibers

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Chinese Optics Letters 2011年第7期9卷 65-68页

作者：吴金东陈丹平吴兴坤邱建荣 State Key Laboratory of Modern Instruments Department of Optical Engineering Zhejiang University Zhejiang Futong optical Fiber Technology Corp. Ltd. Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences State Key Laboratory of Silicon Materials Zhejiang University optical Communication Materials Laboratory South China University of Technology

Bi-doped SiO2-Al2O3-GeO2 fiber preforms are prepared by modified chemical vapor deposition （MCVD） and solution doping process. The characteristic spectra of the preforms and fibers are experimentally investigated, and a distinct difference in emission between the two is observed. Under 808-nm excitation, an ultra-broad near-infrared （NIR） emission with full-width at half-maximum （FWHM） of 495 nm is observed in the Bi-doped fiber. This observation, to our knowledge, is the first in this field. The NIR emission consists of two bands, which may be ascribed to the Bi0 and Bi＋ species, respectively. This Bi-doDed fiber is promising for broadband or）tical amolification and widely tunable laser.

关键词： Broadband amplifiers Chemical vapor deposition fibers Germanium oxides Infrared devices Lasers optical fibers Preforming Silicon compounds

Method to improve the performance of reflectance diffuse optical imaging based on polygonal optical fibers arrangement

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Chinese Optics Letters 2009年第9期7卷 852-856页

作者：李韪韬钱志余李婷 Department of Biomedical Engineering College of Automation EngineeringNanjing University of Aeronautics and Astronautics

In order to improve the performance of reflectance diffuse optical imaging （rDOI）, a novel polynomial geometry （PG） of optical fibers arrangement is proposed. Polynomial geometry is based on the hexagonal geometry （HG） and multicentered double-density （MD） mode. The overlapping sensitivity matrix, area ratio （AR）, reconstruction image, two-absorber model, and contrast-to-noise ratio （CNR） in different depths are used to evaluate the performance of PG. The other three geometries including HG, rectangular geometry （RG）, and MD mode are also compared with PG. The deformation of the reconstruction images is evaluted by circular ratio （CR）. The results prove that the proposed PG has high performance and minimum deformation in quality of reconstruction image in rDOI.

关键词： Computational geometry Deformation optical fibers optical image storage optical materials Reflection Repair

Radiation-induced effects in polarization-maintaining optical fibers for interferometric gyroscope

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Chinese Optics Letters 2011年第6期9卷 21-23页

作者：王学勤张春熹金靖宋凝芳 Institute of Optics and Electronics Beihang University

Radiation-induced attenuation （RIA） in four types of polarization-maintaining optical fibers for interfer-ometric fiberoptic gyroscope （IFOG） at 1310 nm is measured. The measurements are conducted during and after steady-state γ-ray irradiation using a 60 Co source in order to observe significantly different RIA behavior and recovery kinetics. Mechanisms involving dopants and manufacturing process are introduced to analyze the RIA discrepancy as well as to guide the choice and hardening of optical fibers during the design of IFOG. Medium-accuracy IFOG using Ge–F-codoped fiber and pure silica core fiber can survive in the space radiation environment.

关键词： Doping (additives) Fiber optic sensors Germanium Gyroscopes Interferometry optical fibers Polarization Radiation effects Silica

Development of Glass optical fibers 1970-2020,Providing Us the Digitalized Communication World

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材料科学与工程（中英文A版） 2023年第1期13卷 1-12页

作者： Tarja T.Volotinen CBertil A.rvidsson Univ.of Eastern Finland Institute of PhotonicsJoensuu 80130Finland Arvidsson Fiber Optics AB Valla 64161Sweden

New types of communication cables were found to be needed already during the 1960-decade,because the copper cables had,and still would have,too high attenuation and especially limited bandwidth,due to extremely high dispersion at communication signals above 2 Mbit/s.Already the first commercially available multimode optical fibers(1979),developed from pure silica glass with a Ge-doped core,had much lower attenuation at signal frequencies of the order of 2-9 Mbit/s and above it.However,fiber core,cladding and coating materials,cable structures and materials,as well as manufacturing-,measurements-and test methods have been needed to be developed much further to get the reliable fiber cable communication networks.The important development stages and solutions to the most significant childhood problems of the optical fibers and cables are described in this paper.Now over 500 million km of optical fibers are manufactured and installed worldwide for the communication networks.The understanding of how to make the fibers with the very good transmission,mechanical and reliability properties exists at the manufacturers of the fibers and cables.

关键词： optical fibers attenuation problems dispersion problems mechanical strength problems reliability core and cladding materials transmission properties mechanical properties

Hollow-core tapered coupler for large inner diameter hollow-core optical fibers

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Chinese Optics Letters 2003年第1期1卷 15-17页

作者：周桂耀侯峙云侯蓝田刘继刚 Institute of Infrared optical fibers & Sensors Yanshan UniversityQihuangdao 066004

A novel hollow-core tapered coupler has been theoretically designed and fabricated by fiber drawing machine. The coupler's inner wall is coated with a polvcrystalline GeO2 film. The coupling loss of hollow-core tapered coupler is about 0.2 dB. Hollow-core tapered coupler reduces the transmission loss of hollow-core optical fiber (HCOF) by 0.5 dB/m, therefore the coupler is suitable for coupling high power CO2 laser in industrial application.

关键词： Lenses optical fibers

Spatial beam reshaping and large-band nonlinear conversion in rectangular-core phosphate glass fibers

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Frontiers of Optoelectronics 2022年第1期15卷 43-52页

作者： Clement Strutynski Vincent Couderc Tigran Mansuryan Giorgio Santarelli Philippe Thomas Sylvain Danto Thierry Cardinal Institute of Chemistry of the Condensed Matter of Bordeaux(ICMCB) Chemistry Department33608 PessacFrance UMR CNRS 7252 Universitéde LimogesXLIM87060 LimogesFrance LP2N Institut d’Optique Graduate School-CNRS-University of Bordeaux33400 TalenceFrance

Here we present the ability of Nd^(3+)-doped zinc-phosphate glasses to be shaped into rectangular core fibers.At first,the physico-chemical properties of the developed P_(2)O_(5)-based materials are investigated for different concentrations of neo-dymium oxide and core and cladding glass compositions are selected for further fiber development.A modified stack-and-draw technique is used to produce multimode large rectangular-core optical fibers.Self-guided nonlinear effects acting as spatial beam reshaping processes occurring in these newly-developed photonic structures lead to the generation of spectral broadenings in the visible and near-infrared spectral domains.

关键词： Phosphate glasses Neodymium optical fibers Self-focusing Super-continuum

Experimental long-distance quantum secure direct communication

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Science Bulletin 2017年第22期62卷 1519-1524页

作者： Feng Zhu Wei Zhang Yubo Sheng Yidong Huang Tsinghua National Laboratory for Information Science and Technology Department of Electronic Engineering Tsinghua University Beijing 100084 China College of Telecommunications and Information Engineering Nanjing University of Posts and Telecommunication Nanjing 210003 China

Quantum secure direct communication(QSDC) is an important quantum communication branch, which realizes the secure information transmission directly without encryption and decryption processes.Recently, two table-top experiments have demonstrated the principle of QSDC. Here, we report the first long-distance QSDC experiment, including the security test, information encoding, fiber transmission and decoding. After the fiber transmission of 0.5 km, quantum state fidelities of the two polarization entangled Bell states are 91% and 88%, respectively, which are used for information coding. We theoretically analyze the performance of the QSDC system based on current optical communication technologies,showing that QSDC over fiber links of several tens kilometers could be expected. It demonstrates the potential of long-distance QSDC and supports its future applications on quantum communication networks.

关键词： Quantum secure direct communication Polarization entangled Bell state optical fibers Bell’s inequality test Bell state measurement

Spin effect on a single-mode single-polarization optical fiber

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Chinese Optics Letters 2015年第2期13卷 17-22页

作者：季敏宁 Gang-Ding Peng Yanhua Luo Institute of Fiber Optics Key Laboratory of Specialty Fiber Optics and Optical Access NetworksSchool of Communication and Information Engineering Shanghai University School of Electrical Engineering and Telecommunications University of New South Wales

The spin effect on a single-mode single-polarization optical fiber is investigated theoretically and numerically. To get a practical single elliptically polarized fiber the normalized spin rate must be in the range of 0.2–0.35. A single elliptically polarized fiber with a normalized spin rate around 0.224 is demonstrated. It has a broad band from1.530 to 1.558 μm, in which the low-leakage elliptically polarized eigenmode loss is kept within 1.2 d B while the high-leakage elliptically polarized eigenmode loss is greater than 20 d B. This fiber can be used as an elliptical polarizer or applied in current sensing.

关键词： fibers optical fibers Polarization