WorldWideScience

Sample records for nonoverlapping fibers systems

  1. Generation of non-overlapping fiber architecture

    DEFF Research Database (Denmark)

    Chapelle, Lucie; Lévesque, M.; Brøndsted, Povl

    2015-01-01

    of overlapping sphero-cylinders. At the end of the first step, a system of overlapping fibers is obtained. In order to obtain a hard-core configuration where fibers cannot overlap other fibers, we use an iterative method called the force-biased algorithm. It applies virtual forces on each point of the fiber...

  2. Channel estimation for space-time trellis coded-OFDM systems based on nonoverlapping pilot structure

    CSIR Research Space (South Africa)

    Sokoya, O

    2008-09-01

    Full Text Available The performance of space time trellis coded orthogonal frequency division multiplexing (STTC-OFDM) systems relies on accurate channel state information at the receiver for proper decoding. One method of obtaining channel state information...

  3. Nonoverlap Property of the Thue-Morse Sequence

    Science.gov (United States)

    2010-04-20

    Fibonacci Numbers & Applic. 2010. 14. ABSTRACT In this note, we provide a new proof for the nonoverlap property of the Thue- Morse sequence using a...Nonoverlap Property of the Thue-Morse Sequence T.W. Cusicka, P. Stănicăb aDepartment of Mathematics, The State University of New York Buffalo, NY...2010 Abstract In this note, we provide a new proof for the nonoverlap property of the Thue- Morse sequence using a Boolean functions approach and

  4. Optical fiber sensors measurement system and special fibers improvement

    Science.gov (United States)

    Jelinek, Michal; Hrabina, Jan; Hola, Miroslava; Hucl, Vaclav; Cizek, Martin; Rerucha, Simon; Lazar, Josef; Mikel, Bretislav

    2017-06-01

    We present method for the improvement of the measurement accuracy in the optical frequency spectra measurements based on tunable optical filters. The optical filter was used during the design and realization of the measurement system for the inspection of the fiber Bragg gratings. The system incorporates a reference block for the compensation of environmental influences, an interferometric verification subsystem and a PC - based control software implemented in LabView. The preliminary experimental verification of the measurement principle and the measurement system functionality were carried out on a testing rig with a specially prepared concrete console in the UJV Řež. The presented system is the laboratory version of the special nuclear power plant containment shape deformation measurement system which was installed in the power plant Temelin during last year. On the base of this research we started with preparation other optical fiber sensors to nuclear power plants measurement. These sensors will be based on the microstructured and polarization maintaining optical fibers. We started with development of new methods and techniques of the splicing and shaping optical fibers. We are able to made optical tapers from ultra-short called adiabatic with length around 400 um up to long tapers with length up to 6 millimeters. We developed new techniques of splicing standard Single Mode (SM) and Multimode (MM) optical fibers and splicing of optical fibers with different diameters in the wavelength range from 532 to 1550 nm. Together with development these techniques we prepared other techniques to splicing and shaping special optical fibers like as Polarization-Maintaining (PM) or hollow core Photonic Crystal Fiber (PCF) and theirs cross splicing methods with focus to minimalize backreflection and attenuation. The splicing special optical fibers especially PCF fibers with standard telecommunication and other SM fibers can be done by our developed techniques. Adjustment

  5. Non-overlapping domain decomposition methods in structural mechanics

    CERN Document Server

    Gosselet, Pierre; 10.1007/BF02905857

    2012-01-01

    The modern design of industrial structures leads to very complex simulations characterized by nonlinearities, high heterogeneities, tortuous geometries... Whatever the modelization may be, such an analysis leads to the solution to a family of large ill-conditioned linear systems. In this paper we study strategies to efficiently solve to linear system based on non-overlapping domain decomposition methods. We present a review of most employed approaches and their strong connections. We outline their mechanical interpretations as well as the practical issues when willing to implement and use them. Numerical properties are illustrated by various assessments from academic to industrial problems. An hybrid approach, mainly designed for multifield problems, is also introduced as it provides a general framework of such approaches.

  6. Diffusion in the two-dimensional nonoverlapping Lorentz gas

    Science.gov (United States)

    James, Corinne P.; Evans, Glenn T.

    1987-10-01

    The self-diffusion coefficient, velocity autocorrelation function, and distribution of collision times for a two-dimensional nonoverlapping Lorentz gas were calculated using molecular dynamics simulation. The systems studied covered a range of densities, from a packing fraction (πNr2/L2) of 0.01 to 0.8. Self-diffusion coefficients were found to agree to all densities with kinetic theory predictions [A. Weijland and J. M. J. van Leeuwen, Physica 38, 35 (1968)] if the radial distribution function (rdf) was taken into account. The density dependence of the decay of the velocity autocorrelation function was qualitatively different from that predicted by kinetic theory. The distribution of collision times was nearly exponential for all but the highest density studied.

  7. Fiber-optic communication systems

    CERN Document Server

    Agrawal, Govind P

    2010-01-01

    This book provides a comprehensive account of fiber-optic communication systems. The 3rd edition of this book is used worldwide as a textbook in many universities. This 4th edition incorporates recent advances that have occurred, in particular two new chapters. One deals with the advanced modulation formats (such as DPSK, QPSK, and QAM) that are increasingly being used for improving spectral efficiency of WDM lightwave systems. The second chapter focuses on new techniques such as all-optical regeneration that are under development and likely to be used in future communication systems. All othe

  8. Multi-core fiber undersea transmission systems

    DEFF Research Database (Denmark)

    Nooruzzaman, Md; Morioka, Toshio

    2017-01-01

    Various potential architectures of branching units for multi-core fiber undersea transmission systems are presented. It is also investigated how different architectures of branching unit influence the number of fibers and those of inline components.......Various potential architectures of branching units for multi-core fiber undersea transmission systems are presented. It is also investigated how different architectures of branching unit influence the number of fibers and those of inline components....

  9. High pressure fiber optic sensor system

    Science.gov (United States)

    Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N

    2013-11-26

    The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

  10. Raman spectroscopy system with hollow fiber probes

    Science.gov (United States)

    Liu, Bing-hong; Shi, Yi-Wei

    2012-11-01

    A Raman remote spectroscopy system was realized using flexible hollow optical fiber as laser emittion and signal collection probes. A silver-coated hollow fiber has low-loss property and flat transmission characteristics in the visible wavelength regions. Compared with conventional silica optical fiber, little background fluorescence noise was observed with optical fiber as the probe, which would be of great advantages to the detection in low frequency Raman shift region. The complex filtering and focusing system was thus unnecessary. The Raman spectra of CaCO3 and PE were obtained by using the system and a reasonable signal to noise ratio was attained without any lens. Experiments with probes made of conventional silica optical fibers were also conducted for comparisons. Furthermore, a silver-coated hollow glass waveguide was used as sample cell to detect liquid phase sample. We used a 6 cm-long hollow fiber as the liquid cell and Butt-couplings with emitting and collecting fibers. Experiment results show that the system obtained high signal to noise ratio because of the longer optical length between sample and laser light. We also give the elementary theoretical analysis for the hollow fiber sample cell. The parameters of the fiber which would affect the system were discussed. Hollow fiber has shown to be a potential fiber probe or sample cell for Raman spectroscopy.

  11. Ultra Small Integrated Optical Fiber Sensing System

    Directory of Open Access Journals (Sweden)

    Peter Van Daele

    2012-09-01

    Full Text Available This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 μm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL, fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.

  12. A NONOVERLAPPING DOMAIN DECOMPOSITION METHOD FOR EXTERIOR 3-D PROBLEM

    Institute of Scientific and Technical Information of China (English)

    De-hao Yu; Ji-ming Wu; Ji-ming Wu

    2001-01-01

    In this paper, a nonoverlapping domain decomposition method, which is based on the natural boundary reduction(cf. [4, 13, 15]), is developed to solve the boundary value problem in exterior three-dimensional domain of general shape. Convergence analyses both for the exterior spherical domain and the general exterior domain are made. Some numerical examples are also provided to illustrate the method.

  13. NACS: non-overlapping AP's caching scheme to reduce handoff in 802.11 wireless LAN

    CERN Document Server

    Tariq, Usman; Hong, Man-Pyo

    2011-01-01

    With the escalation of the IEEE 802.11 based wireless networks, voice over IP and analogous applications are also used over wireless networks. Recently, the wireless LAN systems are spaciously deployed for public Internet services. In public wireless LAN systems, reliable user authentication and mobility support are indispensable issues. When a mobile device budges out the range of one access point (AP) and endeavor to connect to new AP, it performs handoff. Contemporarily, PNC and SNC were proposed to propagate the MN context to the entire neighboring AP's on the wireless network with the help of neighbor graph. In this paper, we proposed a non-overlapping AP's caching scheme (NACS), which propagates the mobile node context to those AP's which do not overlap with the current AP. To capture the topology of non-overlapping AP's in the wireless network, non-overlapping graph (NOG) is generated at each AP. Simulation results shows that NACS reduces the signaling cost of propagating the MN context to the neighbor...

  14. Fiber laser coupled optical spark delivery system

    Science.gov (United States)

    Yalin, Azer [Fort Collins, CO; Willson, Bryan [Fort Collins, CO; Defoort, Morgan [Fort Collins, CO; Joshi, Sachin [Fort Collins, CO; Reynolds, Adam [Fort Collins, CO

    2008-03-04

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  15. Fiber Optic Temperature Sensors for Thermal Protection Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In Phase 1, Intelligent Fiber Optic Systems Corporation (IFOS), in collaboration with North Carolina State University, successfully demonstrated a Fiber Bragg...

  16. A PARALLEL NONOVERLAPPING DOMAIN DECOMPOSITION METHOD FOR STOKES PROBLEMS

    Institute of Scientific and Technical Information of China (English)

    Mei-qun Jiang; Pei-liang Dai

    2006-01-01

    A nonoverlapping domain decomposition iterative procedure is developed and analyzed for generalized Stokes problems and their finite element approximate problems in RN(N=2,3). The method is based on a mixed-type consistency condition with two parameters as a transmission condition together with a derivative-free transmission data updating technique on the artificial interfaces. The method can be applied to a general multi-subdomain decomposition and implemented on parallel machines with local simple communications naturally.

  17. The DESI fiber positioner system

    Science.gov (United States)

    Schubnell, Michael; Ameel, Jon; Besuner, Robert W.; Gershkovich, Irena; Heetderks, Henry D.; Hoerler, Philipp; Kneib, Jean-Paul; Heetderks, Henry D.; Silber, Joseph H.; Tarlé, Gregory; Weaverdyck, Curtis

    2016-08-01

    The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the baryon acoustic oscillation technique. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5,000 fiber optic positioners feeding ten broad-band spectrographs. The positioners have eccentric axis kinematics. Actuation is provided by two 4mm diameter DC brushless gear-motors. An attached electronics board accepts a DC voltage for power and CAN messages for communications and drives the two motors. The positioner accepts the ferrulized and polished fiber and provides a mechanically safe path through its internal mechanism. Positioning is rapid and accurate with typical RMS errors of less than 5 μm.

  18. MX optical fiber communication system

    Science.gov (United States)

    Keiser, G.

    The fiber optic (FO) network for the proposed MX mobile basing scheme is described. C3 operations would be implemented through 15,000 km of FO links between 4800 sites. Burying the cables would ensure continued C3 operations in a hostile environment, although protection would be needed from burrowing rodents. Technology development criteria, such as optical sources and photodetectors for the 1300-1600 nm long wavelength region, are noted, together with construction of a test site at an Air Force base in California.

  19. Fabrication of Microfluidic Fiber Chip Detection System

    Institute of Scientific and Technical Information of China (English)

    Bo Su; Da-fu Cui; Chang-chun Liu; Xing Chen

    2006-01-01

    The diameter of the excitation beam was decreased greatly by integrating the fiber on the microfluidic chip as light propagation medium. The coupling efficiency of the fiber was improved with optical fiber collimation device coupling beam.The chip was placed in the darkroom to avoid the interference of the external light. The cost of the instrument was decreased with a high brightness blue LED as excitation source; the performance of the system was valuated by the determination of FITC fluorescein with a minimum detectable concentration of 2.2×10-8 mol/L, the Signal-to-Noise Ratio (SNR) S/N=5. The correlation coefficient of the detection system within the range of 1.8 × 10-7 mol/L~ 4 × 10-5mol/L was 0.9972.

  20. Fiber Optic Temperature Sensors for Thermal Protection Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes an innovative fiber optic-based, multiplexable, highly ruggedized, integrated sensor system for real-time...

  1. All-optical photoacoustic imaging system using fiber ultrasound probe and hollow optical fiber bundle.

    Science.gov (United States)

    Miida, Yusuke; Matsuura, Yuji

    2013-09-23

    An all-optical 3D photoacoustic imaging probe that consists of an optical fiber probe for ultrasound detection and a bundle of hollow optical fibers for excitation of photoacoustic waves was developed. The fiber probe for ultrasound is based on a single-mode optical fiber with a thin polymer film attached to the output end surface that works as a Fabry Perot etalon. The input end of the hollow fiber bundle is aligned so that each fiber in the bundle is sequentially excited. A thin and flexible probe can be obtained because the probe system does not have a scanning mechanism at the distal end.

  2. Structural health monitoring system/method using electroactive polymer fibers

    Science.gov (United States)

    Scott-Carnell, Lisa A. (Inventor); Siochi, Emilie J. (Inventor)

    2013-01-01

    A method for monitoring the structural health of a structure of interest by coupling one or more electroactive polymer fibers to the structure and monitoring the electroactive responses of the polymer fiber(s). Load changes that are experienced by the structure cause changes in the baseline responses of the polymer fiber(s). A system for monitoring the structural health of the structure is also provided.

  3. Interpersonal perception and metaperception in nonoverlapping social groups.

    Science.gov (United States)

    Malloy, T E; Albright, L; Kenny, D A; Agatstein, F; Winquist, L

    1997-02-01

    Consensus, self-other agreement, and meta-accuracy were studied within and across nonoverlapping social groups. Thirty-one target persons were judged on the Big Five factors by 9 informants: 3 family members, 3 friends, and 3 coworkers. Although well acquainted within groups, informants were unacquainted between groups. A social relations analysis conducted within each social group showed reliable consensus on the Big Five personality factors. A model specified to estimate the consistency of a target person's effect on perceptions by others across social groups showed weaker agreement across groups. That is, targets were perceived consensually within groups, but these consensual perceptions differed between groups. The data suggest that personality and identity are context specific; however, there was some evidence of agreement in perceptions across groups.

  4. Fiber optic gyroscopes for vehicle navigation systems

    Science.gov (United States)

    Kumagai, Tatsuya; Soekawa, Hirokazu; Yuhara, Toshiya; Kajioka, Hiroshi; Oho, Shigeru; Sonobe, Hisao

    1994-03-01

    Fiber optic gyroscopes (FOGs) have been developed for vehicle navigation systems and are used in Toyota Motor Corporation models Mark II, Chaser and Cresta in Japan. Use of FOGs in these systems requires high reliability under a wide range of conditions, especially in a temperature range between -40 and 85 degree(s)C. In addition, a high cost-performance ratio is needed. We have developed optical and electrical systems that are inexpensive and can perform well. They are ready to be mass-produced. FOGs have already been installed in luxury automobiles, and will soon be included in more basic vehicles. We have developed more inexpensive FOGs for this purpose.

  5. Optical fiber telecommunications systems and networks

    CERN Document Server

    Kaminow, Ivan; Willner, Alan E

    2013-01-01

    Optical Fiber Telecommunications VI (A&B) is the sixth in a series that has chronicled the progress in the R&D of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition brings a fresh look to many essential topics, including devices, subsystems, systems and networks. A central theme is the enabling of high-bandwidth communications in a cost-effective manner for the development of customer applications. These volumes are an ideal reference for R&D engineers and managers, optical systems implementers, university researchers and s

  6. Back-illuminate fiber system research for multi-object fiber spectroscopic telescope

    Science.gov (United States)

    Zhou, Zengxiang; Liu, Zhigang; Hu, Hongzhuan; Wang, Jianping; Zhai, Chao; Chu, Jiaru

    2016-07-01

    In the telescope observation, the position of fiber will highly influence the spectra efficient input in the fiber to the spectrograph. When the fibers were back illuminated on the spectra end, they would export light on the positioner end, so the CCD cameras could capture the photo of fiber tip position covered the focal plane, calculates the precise position information by light centroid method and feeds back to control system. A set of fiber back illuminated system was developed which combined to the low revolution spectro instruments in LAMOST. It could provide uniform light output to the fibers, meet the requirements for the CCD camera measurement. The paper was introduced the back illuminated system design and different test for the light resource. After optimization, the effect illuminated system could compare with the integrating sphere, meet the conditions of fiber position measurement.Using parallel controlled fiber positioner as the spectroscopic receiver is an efficiency observation system for spectra survey, has been used in LAMOST recently, and will be proposed in CFHT and rebuilt telescope Mayall. In the telescope observation, the position of fiber will highly influence the spectra efficient input in the fiber to the spectrograph. When the fibers were back illuminated on the spectra end, they would export light on the positioner end, so the CCD cameras could capture the photo of fiber tip position covered the focal plane, calculates the precise position information by light centroid method and feeds back to control system. After many years on these research, the back illuminated fiber measurement was the best method to acquire the precision position of fibers. In LAMOST, a set of fiber back illuminated system was developed which combined to the low revolution spectro instruments in LAMOST. It could provide uniform light output to the fibers, meet the requirements for the CCD camera measurement and was controlled by high-level observation system which

  7. A Fiber-Optical Intrusion Alarm System Based on Quasi-Distributed Fiber Bragg Grating Sensors

    Institute of Scientific and Technical Information of China (English)

    Qi Jiang; Yun-Jiang Rao; De-Hong Zeng

    2008-01-01

    A fiber-optical intrusion alarm system based on quasi-distributed fiber Bragg grating (FBG) sensors is demonstrated in this paper. The algorithms of empirical mode decomposition (EMD) and wavelet packet characteristic entropy are adopted to determine the intrusion location. The intrusion alarm software based on the Labview is developed, and it is also proved by the experiments. The results show that such a fiber-optical intrusion alarm system can offer the automatic intrusion alarm in real-time.

  8. Study of elastic system fibers in human gingiva

    Directory of Open Access Journals (Sweden)

    Walter Augusto Soares Machado

    Full Text Available Objective: To map the participation of the elastic system fibers of human gingiva. Methods: To conduct this study, fragments of human gingiva from ten individuals aged between 18 and 60 years, removed after periodontal surgery for prosthetic purposes, were analyzed by the histochemical and immuno-histochemical methods, to evaluate the participation of the elastic system fibers in this tissue. Results: The results demonstrated the presence of three type of elastic system fibers, that is to say, oxitalan, elaunin and elastic fibers,distributed as follows: 1 the oxitalan fibers form a network of thin fibers, located close to the basal membrane, at the level of the conjunctive tissue papillae; 2 elaunin fibers are found in close contact with the oxitalan fibers in the papillary and submaxillary regions, following the collagen fiber bundles; 3 a small quantity of elastic fibers were observed, dispersed throughout the deeper conjunctive tissue and around the blood vessels. Conclusion: The three types of elastic system fibers, that is, oxitalan, elaunin and elastic fibers are normal constituents of the extracellular matrixof human gingiva conjunctive tissue.

  9. Design of the fiber optic support system and fiber bundle accelerated life test for VIRUS

    Science.gov (United States)

    Soukup, Ian M.; Beno, Joseph H.; Hayes, Richard J.; Heisler, James T.; Mock, Jason R.; Mollison, Nicholas T.; Good, John M.; Hill, Gary J.; Vattiat, Brian L.; Murphy, Jeremy D.; Anderson, Seth C.; Bauer, Svend M.; Kelz, Andreas; Roth, Martin M.; Fahrenthold, Eric P.

    2010-07-01

    The quantity and length of optical fibers required for the Hobby-Eberly Telescope* Dark Energy eXperiment (HETDEX) create unique fiber handling challenges. For HETDEX‡, at least 33,600 fibers will transmit light from the focal surface of the telescope to an array of spectrographs making up the Visible Integral-Field Replicable Unit Spectrograph (VIRUS). Up to 96 Integral Field Unit (IFU) bundles, each containing 448 fibers, hang suspended from the telescope's moving tracker located more than 15 meters above the VIRUS instruments. A specialized mechanical system is being developed to support fiber optic assemblies onboard the telescope. The discrete behavior of 448 fibers within a conduit is also of primary concern. A life cycle test must be conducted to study fiber behavior and measure Focal Ratio Degradation (FRD) as a function of time. This paper focuses on the technical requirements and design of the HETDEX fiber optic support system, the electro-mechanical test apparatus for accelerated life testing of optical fiber assemblies. Results generated from the test will be of great interest to designers of robotic fiber handling systems for major telescopes. There is concern that friction, localized contact, entanglement, and excessive tension will be present within each IFU conduit and contribute to FRD. The test apparatus design utilizes six linear actuators to replicate the movement of the telescope over 65,000 accelerated cycles, simulating five years of actual operation.

  10. A Simple Method to Control Positive Baseline Trend within Data Nonoverlap

    Science.gov (United States)

    Parker, Richard I.; Vannest, Kimberly J.; Davis, John L.

    2014-01-01

    Nonoverlap is widely used as a statistical summary of data; however, these analyses rarely correct unwanted positive baseline trend. This article presents and validates the graph rotation for overlap and trend (GROT) technique, a hand calculation method for controlling positive baseline trend within an analysis of data nonoverlap. GROT is…

  11. Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics.

    Science.gov (United States)

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M Reza Rahimi

    2016-12-01

    Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO_{2} sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir et al., Sci. Rep. 6, 35024 (2016)2045-232210.1038/srep35024]. A modification of the random sequential addition (RSA) algorithm has been developed to generate such packings, and a variety of microstructural descriptors, including the radial distribution function, the face-normal correlation function, two-point probability and cluster functions, the lineal-path function, the pore-size distribution function, and surface-surface and surface-void correlation functions, have been computed, along with the specific surface and mean chord length of the packings. The results indicate the existence of both spatial and orientational long-range order as the the packing density increases. The maximum packing fraction achievable with the RSA method is about 0.57, which represents the limit for a structure similar to liquid crystals.

  12. Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics

    Science.gov (United States)

    Malmir, Hessam; Sahimi, Muhammad; Tabar, M. Reza Rahimi

    2016-12-01

    Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO2 sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir et al., Sci. Rep. 6, 35024 (2016), 10.1038/srep35024]. A modification of the random sequential addition (RSA) algorithm has been developed to generate such packings, and a variety of microstructural descriptors, including the radial distribution function, the face-normal correlation function, two-point probability and cluster functions, the lineal-path function, the pore-size distribution function, and surface-surface and surface-void correlation functions, have been computed, along with the specific surface and mean chord length of the packings. The results indicate the existence of both spatial and orientational long-range order as the the packing density increases. The maximum packing fraction achievable with the RSA method is about 0.57, which represents the limit for a structure similar to liquid crystals.

  13. Multiparameter fiber optic sensing system for monitoring enhanced geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Challener, William A

    2014-12-04

    The goal of this project was to design, fabricate and test an optical fiber cable which supports multiple sensing modalities for measurements in the harsh environment of enhanced geothermal systems. To accomplish this task, optical fiber was tested at both high temperatures and strains for mechanical integrity, and in the presence of hydrogen for resistance to darkening. Both single mode (SM) and multimode (MM) commercially available optical fiber were identified and selected for the cable based on the results of these tests. The cable was designed and fabricated using a tube-within-tube construction containing two MM fibers and one SM fiber, and without supporting gel that is not suitable for high temperature environments. Commercial fiber optic sensing instruments using Raman DTS (distributed temperature sensing), Brillouin DTSS (distributed temperature and strain sensing), and Raleigh COTDR (coherent optical time domain reflectometry) were selected for field testing. A microelectromechanical systems (MEMS) pressure sensor was designed, fabricated, packaged, and calibrated for high pressure measurements at high temperatures and spliced to the cable. A fiber Bragg grating (FBG) temperature sensor was also spliced to the cable. A geothermal well was selected and its temperature and pressure were logged. The cable was then deployed in the well in two separate field tests and measurements were made on these different sensing modalities. Raman DTS measurements were found to be accurate to ±5°C, even with some residual hydrogen darkening. Brillouin DTSS measurements were in good agreement with the Raman results. The Rayleigh COTDR instrument was able to detect some acoustic signatures, but was generally disappointing. The FBG sensor was used to determine the effects of hydrogen darkening, but drift over time made it unreliable as a temperature or pressure sensor. The MEMS sensor was found to be highly stable and accurate to better than its 0.1% calibration.

  14. Intelligent fiber sensing system for the oil field area

    Science.gov (United States)

    Sun, Wenju; Ma, Linping

    2010-08-01

    Optical Fiber strain sensor using fiber Bragg grating are poised to play a major role in structural health from military to civil engineering. Fiber Bragg Grating sensor is a practical type of fiber optic sensors. Its measurement is encoded with the wavelength of the optical signal reflected from fiber Bragg grating. The method of measuring the absolute optical wavelength is a critical component of the fiber optic sensing system. To reliably detect very small changes in the environment at the sensor, the interrogation system must provide accurate and repeatable wavelength measurements. Energy sources are increasingly scarce in the world. Getting oil from the oil-wells has become more and more difficult. Therefore, new technology to monitor the oil-well condition has become extremely important. The traditional electrical sensor system is no longer useful because of the down-hole's high temperature and high pressure environment. The optical fiber sensing system is the first choice to monitor this condition. This system will reduce the cost and increase the productivity. In the high pressure and high temperature environment, the traditional packed fiber grating pressure-temperature sensor will be no longer reliability. We have to find a new fiber grating temperature-pressure sensor element and the interrogation system. In this work we use the very narrow bandwidth birefringent fiber grating as the sensing element. We obtain the interrogation system has 0.1 pm resolution.

  15. Advanced Components For Fiber-Optical Systems

    Science.gov (United States)

    Depaula, Ramon; Stowe, David W.

    1989-01-01

    Paper reviews statuses of some advanced passive and active optical components for use with optical fibers. Emphasis on highly birefringent components controling polarization, because control of polarization critical in applications as fiber-optical gyroscopes, interferometric sensors, and coherent communications.

  16. Composite Overwrapped Pressure Vessels (COPV) Monitoring System Using Fiber Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes, in this Phase 1 SBIR project, to demonstrate the feasibility of innovations based on an...

  17. Electrical Properties of Carbon Fiber Support Systems

    CERN Document Server

    Cooper, W; Demarteau, M; Fast, J; Hanagaki, K; Johnson, M; Kuykendall, W; Lubatti, H; Matulik, M; Nomerotski, A; Quinn, B; Wang, J

    2005-01-01

    Carbon fiber support structures have become common elements of detector designs for high energy physics experiments. Carbon fiber has many mechanical advantages but it is also characterized by high conductivity, particularly at high frequency, with associated design issues. This paper discusses the elements required for sound electrical performance of silicon detectors employing carbon fiber support elements. Tests on carbon fiber structures are presented indicating that carbon fiber must be regarded as a conductor for the frequency region of 10 to 100 MHz. The general principles of grounding configurations involving carbon fiber structures will be discussed. To illustrate the design requirements, measurements performed with a silicon detector on a carbon fiber support structure at small radius are presented. A grounding scheme employing copper-kapton mesh circuits is described and shown to provide adequate and robust detector performance.

  18. Bidirectional fiber-wireless and fiber-VLLC transmission system based on an OEO-based BLS and a RSOA.

    Science.gov (United States)

    Lu, Hai-Han; Li, Chung-Yi; Lu, Ting-Chien; Wu, Chang-Jen; Chu, Chien-An; Shiva, Ajay; Mochii, Takao

    2016-02-01

    A bidirectional fiber-wireless and fiber-visible-laser-light-communication (VLLC) transmission system based on an optoelectronic oscillator (OEO)-based broadband light source (BLS) and a reflective semiconductor optical amplifier (RSOA) is proposed and experimentally demonstrated. Through an in-depth observation of such bidirectional fiber-wireless and fiber-VLLC transmission systems, good bit error rate performances are obtained over a 40 km single-mode fiber and a 10 m RF/optical wireless transport. Such a bidirectional fiber-wireless and fiber-VLLC transmission system is an attractive option for providing broadband integrated services.

  19. Hybrid CATV/MMW/BB lightwave transmission system based on fiber-wired/fiber-wireless/fiber-VLLC integrations.

    Science.gov (United States)

    Li, Chung-Yi; Lu, Hai-Han; Lu, Ting-Chieh; Chu, Chien-An; Chen, Bo-Rui; Lin, Chun-Yu; Peng, Peng-Chun

    2015-12-14

    A hybrid lightwave transmission system for cable television (CATV)/millimeter-wave (MMW)/baseband (BB) signal transmission based on fiber-wired/fiber-wireless/fiber-visible laser light communication (VLLC) integrations is proposed and demonstrated. For down-link transmission, the light is intensity-modulated with 50-550 MHz CATV signal and optically promoted from 25 GHz radio frequency (RF) signal to 10 Gbps/50 GHz and 20 Gbps/100 GHz MMW data signals based on fiber-wired and fiber-wireless integrations. Good performances of carrier-to-noise ratio (CNR), composite second-order (CSO), composite triple-beat (CTB), and bit error rate (BER) are obtained over a 40-km single-mode fiber (SMF) and a 10-m RF wireless transport. For up-link transmission, the light is successfully intensity-remodulated with 5-Gbps BB data stream based on fiber-VLLC integration. Good BER performance is achieved over a 40-km SMF and a 10-m free-space VLLC transport. Such a hybrid CATV/MMW/BB lightwave transmission system is an attractive alternative, it gives the benefits of a communication link for broader bandwidth and higher transmission rate.

  20. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam

    2011-01-01

    This book provides an in-depth treatment of both linear fiber-optic systems and their key enabling devices. It presents a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers. To the second edition of this book important new aspects of linear fiber-optic transmission technologies are added, such as high level system architectural issues, algorithms for deriving the optimal frequency assignment, directly modulated or externally modulated laser t...

  1. Research on WDM optical fiber transmission system based on fiber Raman amplifier

    Institute of Scientific and Technical Information of China (English)

    Fei Xue(薛飞); Kun Qiu(邱昆); Yue Chen(陈玥)

    2003-01-01

    After wavelength division multiplexing (WDM) optical fiber transmission system based on fiber Raman amplifier (FRA) is investigated in detail, the influence of the collocation of dispersion compensation fiber (DCF), the dispersion coefficient, dispersion slope (DS), effective core area, nonlinear index, length of FRA, launch power and the bandwidth of Bessel filter on bit error rate (BER) is deduced. The influence of Rayleigh backscattering noise on optical signal noise ratio (OSNR) is also investigated, which affects the performance of long haul transmission badly. The result indicates that the broadband long haul transmission can be realized through the reasonable design of the fiber. The result is useful to the optimal design of the WDM optical fiber transmission system based on FRA.

  2. Optical fiber gas sensing system based on FBG filtering

    Science.gov (United States)

    Wang, Shutao

    2008-10-01

    An optical fiber gas sensing system based on the law of Beer-Lambert is designed to determine the concentration of gas. This technique relies on the fact that the target gas has a unique, well-defined absorption characteristic within the infrared region of electromagnetic spectrum. The narrow-band filtering characteristic of optical fiber Bragg grating is used to produce the narrow spectrum light signal. An aspheric objective optical fiber collimator is used in the system as an optical fiber gas sensing detector to improve the sensitivity and stability. Experimental results show there is a high measuring sensitivity at 0.01%, and the measuring range goes beyond 5%.

  3. Single-mode fiber systems for deep space communication network

    Science.gov (United States)

    Lutes, G.

    1982-01-01

    The present investigation is concerned with the development of single-mode optical fiber distribution systems. It is pointed out that single-mode fibers represent potentially a superior medium for the distribution of frequency and timing reference signals and wideband (400 MHz) IF signals. In this connection, single-mode fibers have the potential to improve the capability and precision of NASA's Deep Space Network (DSN). Attention is given to problems related to precise time synchronization throughout the DSN, questions regarding the selection of a transmission medium, and the function of the distribution systems, taking into account specific improvements possible by an employment of single-mode fibers.

  4. Millijoule pulse energy picosecond fiber chirped-pulse amplification system

    Institute of Scientific and Technical Information of China (English)

    Zhi Yang; Xiaohong Hu; Yishan Wang; Wei Zhang; Wei Zhao

    2011-01-01

    @@ The efficient generation of a 1.17-mJ laser pul8e with 360 ps duration using an ytterbium (Yb)-doped fiber amplifier chain seeded by a homemade mode-locked fiber laser is demonstrated experimentally.A specially designed figure-of-eight fiber laser acts as the seed source of a chirped-pulse amplification (CPA) system and generates mode-locked pulse8 with hundreds of picosecond widths.Two kinds of large-mode-area (LMA) double-clad Yb-doped fibers are employed to construct the pre-amplifier and main amplifier, All of the adopted instruments help avoid severe nonlinearity in fibers to raise sub-nanosecond pulse energy with acceptable signal-to-noise ratio (SNR).The output spectrum of this fiber-based CPA system shows that amplified spontaneous emission (ASE) is suppressed to better than 30 dB, and the onset of stimulated Raman scattering is excluded.%The efficient generation of a 1.17-mJ laser pulse with 360 ps duration using an ytterbium (Yb)-doped fiber amplifier chain seeded by a homemade mode-locked fiber laser is demonstrated experimentally. A specially designed figure-of-eight fiber laser acts as the seed source of a chirped-pulse amplification (CPA) system and generates mode-locked pulses with hundreds of picosecond widths. Two kinds of large-mode-area (LMA) double-clad Yb-doped fibers are employed to construct the pre-amplifier and main amplifier. All of the adopted instruments help avoid severe nonlinearity in fibers to raise sub-nanosecond pulse energy with acceptable signal-to-noise ratio (SNR). The output spectrum of this fiber-based CPA system shows that amplified spontaneous emission (ASE) is suppressed to better than 30 dB, and the onset of stimulated Raman scattering is excluded.

  5. Simple fiber optic sensor for applications in security systems

    Science.gov (United States)

    Zyczkowski, M.; Karol, M.; Markowski, P.; Napierala, M. S.

    2014-10-01

    In this paper we demonstrate measurement results of the modalmetric fiber optic sensor used for the monitoring of the fiber optic link integrity to protect it against unauthorized access to classified information. The presented construction is based on the detection of changes of the modes distribution in a multimode fiber. Any mechanical stress on the multimode fiber causes changes of polarization and distribution of propagating modes, hence it changes the distribution of modes at the end of the multimode fiber. Observation of these changes using a narrow core single-mode fiber allows to use the structure as an optical fiber sensor. We used several kilometers long optical links to conduct field tests of laboratory sensor. On this basis the prototype module of modalmetric fiber optic sensor wasbuilt. The modification of optoelectronic part, the variation of sensor length and the change of the method of light reflection at the end of the fiber enable the use of the modalmetric fiber optic sensor in many applications. The sensor finds wide range of applications in security systems. It can be applied to protect the museum's collection, transmission lines and to protect objects of critical infrastructure.

  6. Magnetically-induced solid-phase microextraction fiber actuation system for quantitative headspace and liquid sampling

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Chris; Carter, Jerry; Chambers, David M.

    2017-05-23

    A magnetically-induced SPME fiber actuation system includes a SPME fiber holder and a SPME fiber holder actuator, for holding and magnetically actuating a SPME fiber assembly. The SPME fiber holder has a plunger with a magnetic material to which the SPME fiber assembly is connected, and the magnetic SPME fiber holder actuator has an elongated barrel with a loading chamber for receiving the SPME fiber assembly-connected SPME fiber holder, and an external magnet which induces axial motion of the magnetic material of the plunger to extend/retract the SPME fiber from/into the protective needle of the SPME fiber assembly.

  7. DFB fiber laser as source for optical communication systems

    DEFF Research Database (Denmark)

    Varming, Poul; Hübner, Jörg; Kristensen, Martin

    1997-01-01

    The results demonstrate that DFB fiber lasers are an attractive alternative as sources in telecommunication systems. The lasers show excellent long-term stability with very high signal to noise ratio and a reasonable output power, combined with exceptional temperature stability and inherent fiber...

  8. Optical system components for navigation grade fiber optic gyroscopes

    Science.gov (United States)

    Heimann, Marcus; Liesegang, Maximilian; Arndt-Staufenbiel, Norbert; Schröder, Henning; Lang, Klaus-Dieter

    2013-10-01

    Interferometric fiber optic gyroscopes belong to the class of inertial sensors. Due to their high accuracy they are used for absolute position and rotation measurement in manned/unmanned vehicles, e.g. submarines, ground vehicles, aircraft or satellites. The important system components are the light source, the electro optical phase modulator, the optical fiber coil and the photodetector. This paper is focused on approaches to realize a stable light source and fiber coil. Superluminescent diode and erbium doped fiber laser were studied to realize an accurate and stable light source. Therefor the influence of the polarization grade of the source and the effects due to back reflections to the source were studied. During operation thermal working conditions severely affect accuracy and stability of the optical fiber coil, which is the sensor element. Thermal gradients that are applied to the fiber coil have large negative effects on the achievable system accuracy of the optic gyroscope. Therefore a way of calculating and compensating the rotation rate error of a fiber coil due to thermal change is introduced. A simplified 3 dimensional FEM of a quadrupole wound fiber coil is used to determine the build-up of thermal fields in the polarization maintaining fiber due to outside heating sources. The rotation rate error due to these sources is then calculated and compared to measurement data. A simple regression model is used to compensate the rotation rate error with temperature measurement at the outside of the fiber coil. To realize a compact and robust optical package for some of the relevant optical system components an approach based on ion exchanged waveguides in thin glass was developed. This waveguides are used to realize 1x2 and 1x4 splitter with fiber coupling interface or direct photodiode coupling.

  9. Ultra-high Frequency Linear Fiber Optic Systems

    CERN Document Server

    Lau, Kam Y

    2009-01-01

    Designed for a one-semester course on fiber-optics systems and communication links, this book provides a concise but rigorous treatment of the theory and practice of analog (linear) fiber-optics links and systems that constitute the foundation of Hybrid Fiber Coax infrastructure in present-day CATV distribution and cable modem Internet access. Emerging applications in remote fiber-optic feed for free-space millimeter wave enterprise campus networks are also described. Issues such as dispersion and interferometric noise are treated quantitatively, and means for mitigating them are explained. This broad but concise text will thus be invaluable not only to students of fiber-optics communication but also to practicing engineers.

  10. Morphology of collagen fibers and elastic system fibers in actinic cheilitis

    Directory of Open Access Journals (Sweden)

    Sgarbi Flavia

    2010-01-01

    Full Text Available Background: Actinic cheilitis (AC is a premalignant condition intimately related to exposure of the lips to sun rays. Aim: The objective of this study was to evaluate the elastic and collagen fibers in the lamina propria of AC. The degree of epithelial atypia was correlated with the quantity of elastic and collagen fibers. Materials and Methods: Fifty-one cases were investigated. One slide was stained with hematoxylin-eosin for the evaluation of atypia, the second was stained with Weigert′s resorcin-fuchsin for the assessment of elastic fibers, and the third slide was stained with Mallory′s trichrome for the analysis of collagen fibers. Results: Ordinal logistic regression analysis revealed a significant correlation between the presence of atypia and collagen fibers (P<0.05. Conclusions: It was concluded that there seems to be a reduction in the quantity of collagen fibers in cases of moderate and severe atypia. No correlation was observed between the degradation of elastic system fibers and the grade of dysplasia.

  11. Design of high-capacity fiber-optic transport systems

    Science.gov (United States)

    Liao, Zhi Ming

    2001-08-01

    We study the design of fiber-optic transport systems and the behavior of fiber amplifiers/lasers with the aim of achieving higher capacities with larger amplifier spacing. Solitons are natural candidates for transmitting short pulses for high-capacity fiber-optic networks because of its innate ability to use two of fiber's main defects, fiber dispersion and fiber nonlinearity to balance each other. In order for solitons to retain its dynamic nature, amplifiers must be placed periodically to restore powers to compensate for fiber loss. Variational analysis is used to study the long-term stability of a periodical- amplifier system. A new regime of operation is identified which allows the use of a much longer amplifier spacing. If optical fibers are the blood vessels of an optical communication system, then the optical amplifier based on erbium-doped fiber is the heart. Optical communication systems can avoid the use of costly electrical regenerators to maintain system performance by being able to optically amplify the weakened signals. The length of amplifier spacing is largely determined by the gain excursion experienced by the solitons. We propose, model, and demonstrate a distributed erbium-doped fiber amplifier which can drastically reduce the amount of gain excursion experienced by the solitons, therefore allowing a much longer amplifier spacing and superior stability. Dispersion management techniques have become extremely valuable tools in the design of fiber-optic communication systems. We have studied in depth the advantage of different arnplification schemes (lumped and distributed) for various dispersion compensation techniques. We measure the system performance through the Q factor to evaluate the added advantage of effective noise figure and smaller gain excursion. An erbium-doped fiber laser has been constructed and characterized in an effort to develop a test bed to study transmission systems. The presence of mode-partition noise in an erbium

  12. RFID-over-Fiber system for agricultural exploitations - Wireless track and trace with range extension using optical fiber

    DEFF Research Database (Denmark)

    Madsen, Peter; Suhr, Lau Frejstrup; Cavalcante, Lucas Costa Pereira

    2015-01-01

    This paper proposes and demonstrates an RFIDover-Fiber wireless track and trace system using active RFID tags and operating over distances up to 30 km of optical fiber and 35 meters of wireless readability......This paper proposes and demonstrates an RFIDover-Fiber wireless track and trace system using active RFID tags and operating over distances up to 30 km of optical fiber and 35 meters of wireless readability...

  13. A 158 fs 5.3 nJ fiber-laser system at 1 mu m using photonic bandgap fibers for dispersion control and pulse compression

    DEFF Research Database (Denmark)

    Nielsen, C.K.; Jespersen, Kim Giessmann; Keiding, S.R.

    2006-01-01

    We demonstrate a 158 fs 5.3 nJ mode-locked laser system based on a fiber oscillator, fiber amplifier and fiber compressor. Dispersion compensation in the fiber oscillator was obtained with a solid-core photonic bandgap (SC-PBG) fiber spliced to standard fibers, and external compression is obtaine...

  14. Fiber laser system for cesium and rubidium atom interferometry

    CERN Document Server

    Diboune, Clément; Bidel, Yannick; Cadoret, Malo; Bresson, Alexandre

    2016-01-01

    We present an innovative fiber laser system for both cesium and rubidium manipulation. The architecture is based on frequency conversion of two lasers at 1560 nm and 1878 nm. By taking advantage of existing fiber components at these wavelengths, we demonstrate an all fiber laser system delivering 350 mW at 780 nm for rubidium and 210 mW at 852 nm for cesium. This result highlights the promising nature of such laser system especially for Cs manipulation for which no fiber laser system has been reported. It offers new perspectives for the development of atomic instruments dedicated to onboard applications and opens the way to a new generation of atom interferometers involving three atomic species $^{85}$Rb, $^{87}$Rb and $^{133}$Cs for which we propose an original laser architecture.

  15. FTTA System Demo Using Optical Fiber-Coupled Active Antennas

    Directory of Open Access Journals (Sweden)

    Niels Neumann

    2014-08-01

    Full Text Available The convergence of optical and wireless systems such as Radio-over-Fiber (RoF networks is the key to coping with the increasing bandwidth demands due to the increasing popularity of video and other high data rate applications. A high level of integration of optical technologies enables simple base stations with a fiber-to-the-antenna (FTTA approach. In this paper, we present a complete full-duplex RoF–FTTA system consisting of integrated active fiber-coupled optical receiving and transmitting antennas that are directly connected to a standard single mode fiber optical link. Data rates up to 1 Gbit/s could be shown without advanced modulation formats on a 1.5 GHz carrier frequency. The antennas as well as the whole system are explained and the results of the system experiments are discussed.

  16. Synchronous Chaos Generation in an ^-Doped Fiber Laser System

    National Research Council Canada - National Science Library

    Gomez-Pavon, L. C; Munoz-Pacheco, J. M; Luis-Ramos, A

    2015-01-01

    ...+ -doped fiber lasers is experimentally analyzed. Using a single amplitude modulator in the system, synchronous chaos generation is obtained at two different modulation frequencies, i.e., 10.38 and 3.85 MHz...

  17. Novel Hemispherical Scanner for a Coherent Fiber LIDAR System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SibellOptics proposes to develop an eye-safe, long-range, compact, versatile, all-fiber wind LIDAR system for atmospheric wind velocity measurement applications that...

  18. Design of optical fiber cable television distribution systems using erbium-doped fiber amplifiers

    Science.gov (United States)

    Zhang, Jian-Guo; Sharma, A. B.; Ritthisoonthorn, Pichet

    1998-04-01

    Optical fiber distribution systems with intensity- modulation/direct-detection and erbium-doped fiber amplifiers are designed for cable television (CATV) applications. Two types of system configurations are considered, i.e., the passive power splitter with optically preamplified receivers (PPS-OPR) scheme and the hybrid passive-and-active power splitter (HPAPS) scheme. The receiver sensitivity is calculated for various system parameters. We compare both schemes through the number of CATV subscribers and show that the HPAPS scheme is superior to the PPS-OPR scheme for large- scale CATV distribution applications.

  19. Laser heated pedestal growth system commissioning and fiber processing

    Science.gov (United States)

    Buric, Michael; Yip, M. J.; Chorpening, Ben; Ohodnicki, Paul

    2016-05-01

    A new Laser Heated Pedestal Growth system was designed and fabricated using various aspects of effective legacy designs for the growth of single-crystal high-temperature-compatible optical fibers. The system is heated by a 100-watt, DC driven, CO2 laser with PID power control. Fiber diameter measurements are performed using a telecentric video system which identifies the molten zone and utilizes edge detection algorithms to report fiber-diameter. Beam shaping components include a beam telescope; along with gold-coated reflaxicon, turning, and parabolic focusing mirrors consistent with similar previous systems. The optical system permits melting of sapphire-feedstock up to 1.5mm in diameter for growth. Details regarding operational characteristics are reviewed and properties of single-crystal sapphire fibers produced by the system are evaluated. Aspects of the control algorithm efficacy will be discussed, along with relevant alternatives. Finally, some new techniques for in-situ processing making use of the laser-heating system are discussed. Ex-situ fiber modification and processing are also examined for improvements in fiber properties.

  20. Intruder localization and identification in fiber optic systems

    Science.gov (United States)

    Zyczkowski, M.

    2008-10-01

    The ultimate goal in all fiber optic systems is to extract information about the mechanical perturbations. For example, this information may be the frequency dependent index of perturbation. For security systems we desire to detect and differentiate between different intruders based on the mechanical response. This article shows experimental investigation of ideal intruder classifier. We considered demodulation, denoising, deconvolution and normalisation. We present additionally possible configuration of fiber optic sensor to localizing perturbation place.

  1. Review of High-Speed Fiber Optic Grating Sensors Systems

    Energy Technology Data Exchange (ETDEWEB)

    Udd, E; Benterou, J; May, C; Mihailov, S J; Lu, P

    2010-03-24

    Fiber grating sensors can be used to support a wide variety of high speed measurement applications. This includes measurements of vibrations on bridges, traffic monitoring on freeways, ultrasonic detection to support non-destructive tests on metal plates and providing details of detonation events. This paper provides a brief overview of some of the techniques that have been used to support high speed measurements using fiber grating sensors over frequency ranges from 10s of kHz, to MHZ and finally toward frequencies approaching the GHz regime. Very early in the development of fiber grating sensor systems it was realized that a high speed fiber grating sensor system could be realized by placing an optical filter that might be a fiber grating in front of a detector so that spectral changes in the reflection from a fiber grating were amplitude modulated. In principal the only limitation on this type of system involved the speed of the output detector which with the development of high speed communication links moved from the regime of 10s of MHz toward 10s of GHz. The earliest deployed systems involved civil structures including measurements of the strain fields on composite utility poles and missile bodies during break tests, bridges and freeways. This was followed by a series of developments that included high speed fiber grating sensors to support nondestructive testing via ultrasonic wave detection, high speed machining and monitoring ship hulls. Each of these applications involved monitoring mechanical motion of structures and thus interest was in speeds up to a few 10s of MHz. Most recently there has been interest in using fiber grating to monitor the very high speed events such as detonations and this has led to utilization of fiber gratings that are consumed during an event that may require detection speeds of hundreds of MHz and in the future multiple GHz.

  2. Beam shaping element for compact fiber injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Weichman, L.S.; Dickey, F.M.; Shagam, R.N.

    2000-01-05

    Injection of high power, multi-mode laser profiles into a fiber optic delivery system requires controlling a number of injection parameters to maximize throughput and minimize concerns for optical damage both at the entrance and exit faces of the fiber optic. A simple method for simultaneously achieving a compact fiber injection geometry and control of these injection parameters, independent of the input source characteristics, is provided by a refractive lenslet array and simple injection lens configuration. Design criteria together with analytical and experimental results for the refractive lenslet array and short focal length injection lens are presented. This arrangement provides a uniform spatial intensity distribution at the fiber injection plane to a large degree independent of the source mode structure, spatial profile, divergence, size, and/or alignment to the injection system. This technique has application to a number of laser systems where uniform illumination of a target or remote delivery of high peak power is desired.

  3. THE PARALLEL CONFOCAL DETECTING SYSTEM USING OPTICAL FIBER PLATE

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective Focusing on the problem such as slow scanning speed, complex system design and low light efficiency, a new parallel confocal 3D profile detecting method based on optical fiber technology, which realizes whole-field confocal detecting, is proposed. Methods The optical fiber plate generates an 2D point light source array, which splits one light beam into N2 subbeams and act the role of pinholes as point source and point detecting to filter the stray light and reflect light. By introducing the construction and working principle of the multi-beam 3D detecting system, the feasibility is investigated. Results Experiment result indicates that the optical fiber technology is applicable in rotation. The measuring parameters that influence the detecting can easily be adapted to satisfy different requirments of measurement. Compared with the conventional confocal method, the parallel confocal detecting system using optical fiber plate is simple in the mechanism, the measuring field is larger and the speed is faster.

  4. Fiber Optic Experience with the Smart Actuation System on the F-18 Systems Research Aircraft

    Science.gov (United States)

    Zavala, Eddie

    1997-01-01

    High bandwidth, immunity to electromagnetic interference, and potential weight savings have led to the development of fiber optic technology for future aerospace vehicle systems. This technology has been incorporated in a new smart actuator as the primary communication interface. The use of fiber optics simplified system integration and significantly reduced wire count. Flight test results showed that fiber optics could be used in aircraft systems and identified critical areas of development of fly-by-light technology. This paper documents the fiber optic experience gained as a result of this program, and identifies general design considerations that could be used in a variety of specific applications of fiber optic technology. Environmental sensitivities of fiber optic system components that significantly contribute to optical power variation are discussed. Although a calibration procedure successfully minimized the effect of fiber optic sensitivities, more standardized calibration methods are needed to ensure system operation and reliability in future aerospace vehicle systems.

  5. Development of a distributed radiation detection system using optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, F.; Inouchi, Goro; Takada, Eiji; Takahashi, Hiroyuki; Iguchi, Tetsuo; Nakazawa, Masaharu [Tokyo Univ. (Japan). Faculty of Engineering; Kakuta, Tsunemi

    1996-07-01

    We have confirmed the importance of temperature and dose rate for the response of Ge-doped fibers to radiation. A phenomenological model have been found to account for temperature and dose rate effects. From this model it is possible to make dose predictions from attenuation measurements when the temperature and dose rate are known. Ge-doped fibers have been found to have a relatively low sensitivity to both neutron and gamma radiation. In addition, temperature and dose rate dependencies complicate the analysis. However we point out that these problems may all be solved if we use fibers, such as P-doped fibers, which contain color centers of long lifetime. This would remove both the temperature and dose rate dependencies that complicate the use of Ge-doped fibers, in addition the radiation sensitivity is increased. Finally OTDR has been investigated as a possible read-out method for distributed radiation measurements. For our system the minimum pulse length was 3ns, giving a spatial resolution in the meter range and a response length to radiation of about 10 m if accurate dose values where to be obtained. We found OTDR to be a suitable method for radiation induced attenuation measurements in optical fibers, especially for long fiber lengths and long time scales where questions of light source stability becomes important for other systems. (S.Y.)

  6. Fiber optic direct Raman imaging system based on a hollow-core fiber bundle

    Science.gov (United States)

    Inoue, S.; Katagiri, T.; Matsuura, Y.

    2015-03-01

    A Raman imaging system which combined a hollow fiber bundle and a direct imaging technique was constructed for high-speed endoscopic Raman imaging. The hollow fiber bundle is fabricated by depositing a silver thin film on the inner surface of pre-drawn glass capillary bundle. It performs as a fiber optic probe which transmits a Raman image with high signal-to-noise ratio because the propagating light is confined into the air core inducing little light scattering. The field of view on the sample is uniformly irradiated by the excitation laser light via the probe. The back-scattered image is collected by the probe and captured directly by an image sensor. A pair of thin film tunable filters is used to select target Raman band. This imaging system enables flexible and high-speed Raman imaging of biological tissues.

  7. Electrospinning of Grooved Polystyrene Fibers: Effect of Solvent Systems

    Science.gov (United States)

    Liu, Wanjun; Huang, Chen; Jin, Xiangyu

    2015-05-01

    Secondary surface texture is of great significance to morphological variety and further expands the application areas of electrospun nanofibers. This paper presents the possibility of directly electrospinning grooved polystyrene (PS) fibers using both single and binary solvent systems. Solvents were classified as low boiling point solvent (LBPS): dichloromethane (DCM), acetone (ACE), and tetrahydrofuran (THF); high boiling point solvent (HBPS): N, N-dimethylformamide (DMF) and cyclohexanone (CYCo); and non-solvent (NS): 1-butanol (BuOH). By the systematic selection and combination of these solvents at given parameters, we found that single solvent systems produced non-grooved fibers. LBPS/DMF solvent systems resulted in fibers with different grooved textures, while LBPS/CYCo led to fibers with double grooved texture. Grooved fibers can also be fabricated from LBPS/LBPS, NS/LBPS, and NS/HBPS systems under specific conditions. The results indicated that the difference of evaporation rate (DER) between the two solvents played a key role in the formation of grooved texture. The formation of this unique texture should be attributed to three separate mechanisms, namely void-based elongation, wrinkle-based elongation, and collapsed jet-based elongation. Our findings can serve as guidelines for the preparation of ultrafine fibers with grooved secondary texture.

  8. Parametric Analysis of Fiber Non-Linearity in Optical systems

    Directory of Open Access Journals (Sweden)

    Abhishek Anand

    2013-06-01

    Full Text Available With the advent of technology Wavelength Division Multiplexing (WDM is always an area of interest in the field of optical communication. When combined with Erbium Doped Fiber Amplifier (EDFA, it provides high data transmission rate and low attenuation. But due to fiber non-linearity such as Self Phase Modulation (SPM and Cross Phase Modulation (XPM the system performance has degraded. This non-linearity depends on different parameters of an optical system such as channel spacing, power of the channel and length of the fiber section. The degradation can be seen in terms of phase deviation and Bit Error Rate (BER performance. Even after dispersion compensation at the fiber end, residual pulse broadening still exists due to cross talk penalty.

  9. Ultrafast fiber beam delivery: system technology and industrial application

    Science.gov (United States)

    Funck, Max C.; Eilzer, Sebastian; Wedel, Björn

    2017-02-01

    Flexible beam delivery of high power pico- and femtosecond pulses offers great advantages in industrial applications. Complex free space beam delivery as found in robot or gantry systems can be replaced, laser safety and uptime increased and system integration in production environment simplified. Only recently fiber beam delivery has become available for ultrafast lasers while it has been an established standard for cw and pulsed laser sources for many years. Using special kinds of fiber that guide the laser beam mostly inside a hollow core, nonlinear effects and catastrophic damage that would arise in conventional glass fibers can be avoided. Today, ultrafast pulses with several 100 μJ and hundreds of MW can be transmitted in quasi single mode fashion with micro-structured hollow core fibers. During the last years we have developed a modular beam delivery system that suits industrial ultrafast lasers and can be integrated into existing processing machines. Micro-structured hollow core fibers inside the sealed laser light cable efficiently guide high-power laser pulses over distances of several meters with excellent beam quality, while power, pulse duration and polarization are maintained. We report on the technology required for fiber beam delivery of ultrafast laser pulses and discuss requirements for successful integration into industrial production as well as achievable performance under realistic operation and show examples of micromachining applications.

  10. Highly-stable monolithic femtosecond Yb-fiber laser system based on photonic crystal fibers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2010-01-01

    of around 297 fs duration. Our laser shows exceptional stability. No Q-switched modelocking events were detected during 4-days long observation. An average fluctuation of only 7.85 · 10−4 over the mean output power was determined as a result of more than 6-hours long measurement. The laser is stable towards......A self-starting, passively stabilized, monolithic all polarizationmaintaining femtosecond Yb-fiber master oscillator / power amplifier with very high operational and environmental stability is demonstrated. The system is based on the use of two different photonic crystal fibers. One is used...... in the oscillator cavity for dispersion balancing and nonlinear optical limiting, and another one is used for low nonlinearity final pulse recompression. The chirped-pulse amplification and recompression of the 232-fs, 45-pJ/pulse oscillator output yields a final direct fiber-end delivery of 7.3-nJ energy pulses...

  11. Fiber-Optic Monitoring System of Particle Counters

    Directory of Open Access Journals (Sweden)

    A. A. Titov

    2016-01-01

    Full Text Available The article considers development of a fiber-optic system to monitor the counters of particles. Presently, optical counters of particles, which are often arranged at considerable distance from each other, are used to study the saltation phenomenon. For monitoring the counters, can be used electric communication lines.However, it complicates and raises the price of system Therefore, we offered a fiber-optic system and the counter of particles, free from these shortcomings. The difference between the offered counter of particles and the known one is that the input of radiation to the counter and the output of radiation scattering on particles are made by the optical fibers, and direct radiation is entered the optical fiber rather than is delayed by a light trap and can be used for lighting the other counters thereby allowing to use their connection in series.The work involved a choice of the quartz multimode optical fiber for communication, defining the optical fiber and lenses parameters of the counter of particles, and a selection of the radiation source and the photo-detector.Using the theory of light diffraction on a particle, a measuring range of the particle sizes has been determined. The system speed has been estimated, and it has been shown that a range of communication can reach 200km.It should be noted that modulation noise of counters of particles connected in series have the impact on the useful signal. To assess the extent of this influence we have developed a calculation procedure to illustrate that with ten counters connected in series this influence on the signal-to-noise ratio will be insignificant.Thus, it has been shown that the offered fiber-optic system can be used for monitoring the counters of particles across the desertified territories. 

  12. WDM Phase-Modulated Millimeter-Wave Fiber Systems

    DEFF Research Database (Denmark)

    Yu, Xianbin; Prince, Kamau; Gibbon, Timothy Braidwood

    2012-01-01

    This chapter presents a computer simulation case study of two typical WDM phase-modulated millimeter-wave systems. The phase-modulated 60 GHz fiber multi-channel transmission systems employ single sideband (SSB) and double sideband subcarrier modulation (DSB-SC) schemes and present one of the lat......This chapter presents a computer simulation case study of two typical WDM phase-modulated millimeter-wave systems. The phase-modulated 60 GHz fiber multi-channel transmission systems employ single sideband (SSB) and double sideband subcarrier modulation (DSB-SC) schemes and present one...... of the latest research efforts in the rapidly emerging Radio-over-Fiber (RoF) application space for in-house access networks....

  13. Fiber-wireless sensor system based on a power-over-fiber technique

    Science.gov (United States)

    Wang, Jin; Yan, Jing; Ding, Yanwen; Lu, Yunqing; Jiang, Jian; Wan, Hongdan; Xu, Ji

    2016-03-01

    A fiber-wireless sensor system based on a power-over-fiber technique is developed to offer a flexible, distributed sensing ability over a middle distance, especially under environments that are sensitive to electromagnetic interference. In this system, the optical energy of a high-power laser in the base station is transmitted via a fiber and then converted into electrical energy by a photovoltaic power converter (PPC) in the remote unit. This optically power-supplied remote unit operates as the coordinator in the wireless sensor network (WSN) and exchanges the sensing information with the base station via another fiber. In our demonstration system, the sensing information can be collected by a WSN 2 km away and be transmitted back. In order to improve the power supply ability of PPC, a maximum power point tracking technique is applied. More than 80% of PPC's maximum output power can be obtained. Moreover, to reduce the power consumption of the remote unit and the sensor nodes, a simple and stable low-power communication protocol is designed.

  14. LFS-90 - A modular system design with fiber optic gyros

    Science.gov (United States)

    Handrich, E.; Bueschelberger, H. J.; Kemmler, M.; Krings, M.

    The general design and the main components of the LFS-90, a fiber optic three-axis rate gyro package intended for flight control applications, are described. The LFS-90 fiber gyro system has a modular structure including a sensor module, an opto-module, a digital control module, and a data processor. With the addition of more modules, the system can be extended to a complete attitude and heading reference system for aerospace applications or a low-cost navigator for land vehicles. LFS-90 test data are presented, including the scale factor, bias, and random walk of the main parameters.

  15. Polarization mode dispersion in optical fiber transmission systems

    Science.gov (United States)

    Cameron, John Charles

    The birefringence of optical fibers causes pulse broadening in fiber-optic communication systems. This phenomenon is known as polarization mode dispersion (PMD). PMD is one of the most important limiting factors for high capacity fiber-optic systems. A number of aspects of PMD are examined in this thesis. In Chapter 2 an expression is derived for the probability density function of the pulse broadening due to first-order PMD. This result is used to obtain an expression for the system limitation due to PMD. The birefringence of optical fibers is commonly simulated with the waveplate model. In Chapter 3 two standard versions of the waveplate model are introduced. In addition, a novel waveplate model is proposed. The characteristics of the three versions of the waveplate model are examined to confirm their suitability for use in subsequent chapters of the thesis. Simulations with the waveplate model are performed in Chapter 4 for three purposes: (1) to determine the impact of chromatic dispersion on the system limitation due to PMD, (2) to examine the effectiveness of three different PMD compensation techniques in the presence of chromatic dispersion, and (3) to examine the interaction of second-order chromatic dispersion with PMD. The simulations in Chapter 4 reveal that it is possible with one compensation technique to have output pulses that are narrower than the input pulses. In Chapter 5, this anomalous pulse narrowing is demonstrated analytically for a simple model of PMD and through experiment. It is also shown that this pulse narrowing can be explained as an interference phenomenon. Chapter 6 presents measurements of PMD and state of polarization on installed optical fibers. The PMD coefficients of 122 fibers are presented and the results are analyzed in terms of the age of the fibers and the type of cabling. Measurements of the time evolution of PMD and state of polarization are presented for fibers installed in both buried and aerial cables. The uncertainty

  16. Fiber-Based, Injection-Molded Optofluidic Systems

    DEFF Research Database (Denmark)

    Matteucci, Marco; Triches, Marco; Nava, Giovanni

    2015-01-01

    We present a method to fabricate polymer optofluidic systems by means of injection molding that allow the insertion of standard optical fibers. The chip fabrication and assembly methods produce large numbers of robust optofluidic systems that can be easily assembled and disposed of, yet allow...

  17. Kansas Communication and Instruction System through Fiber-Optic Transmission.

    Science.gov (United States)

    Kansas State Dept. of Education, Topeka.

    Schools and communities will restructure as they move into the next decade. The success of this restructuring will be dependent upon access to and sharing of quality teaching and information through an expanded communication system. One of the major two-way interactive technologies is the fiber-optic cable: a delivery system that will provide…

  18. Precision-analog fiber-optic transmission system

    Energy Technology Data Exchange (ETDEWEB)

    Stover, G.

    1981-06-01

    This article describes the design, experimental development, and construction of a DC-coupled precision analog fiber optic link. Topics to be covered include overall electrical and mechanical system parameters, basic circuit organization, modulation format, optical system design, optical receiver circuit analysis, and the experimental verification of the major design parameters.

  19. Noise and signal interference in optical fiber transmission systems an optimum design approach

    CERN Document Server

    Bottacchi, Stefano

    2008-01-01

    A comprehensive reference to noise and signal interference in optical fiber communications Noise and Signal Interference in Optical Fiber Transmission Systems is a compendium on specific topics within optical fiber transmission and the optimization process of the system design. It offers comprehensive treatment of noise and intersymbol interference (ISI) components affecting optical fiber communications systems, containing coverage on noise from the light source, the fiber and the receiver. The ISI is modeled with a statistical approach, leading to new useful computational m

  20. Directly modulated cable television transport systems using negative dispersion fiber

    Science.gov (United States)

    Lu, Hai-Han; Liaw, Je-Wei; Lee, Yi-Shiuan; Tsai, Wan-Lin; Ji, Yu-Jie

    2005-03-01

    A directly modulated AM-VSB cable-television transport system using negative dispersion fiber (NDF) as the transmission medium is proposed and successfully demonstrated. Good performances of carrier-to-noise radio, composite second order, and composite triple beat were obtained over a 70-km NDF transport without optical amplification. The directly modulated laser has a positive chirp, while NDF has a negative dispersion property in the transmission fiber. This negative dispersion property compensates for the laser chirp and results in a system with better transmission performance.

  1. An All Fiber White Light Interferometric Absolute Temperature Measurement System

    Directory of Open Access Journals (Sweden)

    Jeonggon Harrison Kim

    2008-11-01

    Full Text Available Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement system is presented using the previously proposed signal processing algorithm. Stability and absolute temperature measurement were demonstrated. These two tests demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe and 0.0005 fringe, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.

  2. Characterization and application of optical fibers: 1. Application of optical fibers in gas concentration and radiation dose measurements. 2. Polarization effects in fiber communication systems

    Science.gov (United States)

    Lu, Ping

    The thesis consists of two research directions: Optical fiber applications in gas concentration and radiation dose measurements; and polarization effects in fiber optic communication systems. Part I of the thesis presents two optical fiber applications. (1) An infrared (IR) fiber bundle has been designed and fabricated to measure gas concentrations in a chemical vapor deposition (CVD) chamber using Fourier transform infrared spectroscopy. This fiber bundle covers the IR range from 0.5 to 20 mum and reduces the light beam divergence in the CVD chamber, which makes it possible to measure gas concentrations in a region near the substrate surface. Semi-ellipsoid mirrors have been designed and used to increase the collection efficiency of infrared radiation and to compensate the loss introduced by the fiber bundle. (2) A fiber optic radiation sensor based on radiation-induced fiber loss is reported. The gamma radiation-induced loss spectra in various fibers have been studied. Among all the fibers tested, 5% P-doped fiber shows the highest sensitivity to gamma radiation. The wavelength and dose rate dependence of radiation-induced loss in 5% P-doped fiber are investigated and the possibility of using this fiber as a radiation sensor for radiation therapy is discussed. Part II of the thesis examines two polarization effects, polarization mode dispersion (PMD) and polarization dependent loss (PDL), in fiber optic communication systems based on the waveplate models. A new waveplate model, capable of generating any PMD and PDL values, is proposed to overcome the limitations of the conventional waveplate model. Using both models the statistical distributions of PDL and differential group delay (DGD) have been studied considering the presence of biased elliptical birefringence. The principal state of polarization (PSP) of an optical pulse is proposed for a fiber having both PMD and PDL. PMD and PDL of a pulse for a fiber consisting of two polarization maintaining fiber

  3. Advanced in In Situ Inspection of Automated Fiber Placement Systems

    Science.gov (United States)

    Juarez, Peter D.; Cramer, K. Elliott; Seebo, Jeffrey P.

    2016-01-01

    Automated Fiber Placement (AFP) systems have been developed to help take advantage of the tailorability of composite structures in aerospace applications. AFP systems allow the repeatable placement of uncured, spool fed, preimpregnated carbon fiber tape (tows) onto substrates in desired thicknesses and orientations. This automated process can incur defects, such as overlapping tow lines, which can severely undermine the structural integrity of the part. Current defect detection and abatement methods are very labor intensive, and still mostly rely on human manual inspection. Proposed is a thermographic in situ inspection technique which monitors tow placement with an on board thermal camera using the preheated substrate as a through transmission heat source. An investigation of the concept is conducted, and preliminary laboratory results are presented. Also included will be a brief overview of other emerging technologies that tackle the same issue. Keywords: Automated Fiber Placement, Manufacturing defects, Thermography

  4. Distributed vibration fiber sensing system based on Polarization Diversity Receiver

    Science.gov (United States)

    Zhang, Junan; Jiang, Peng; Hu, Zhengliang; Hu, Yongming

    2016-10-01

    In this paper, we propose a distributed vibration fiber sensing system based on Polarization Diversity Receiver(PDR). We use Acoustic Optical Modulator(AOM) to generate pulse light and an unbalanced M-Z interferometer to generate two pulse light with a certain time delay in the same period. As the pulse lights propagating in fibers, the Backward Rayleigh scattering lights will interfere with each other. The vibration on the fiber will change the length and refractive index of fiber which results in the change of the phase of the interference signal. Hence, one arm of the M-Z interferometer is modulated by a sinusoidal phase-generated carrier(PGC) signal, and PGC demodulation algorithm has been used to acquire phase information from the Backward Rayleigh scattering lights. In order to overcome the influence of polarization-induced fading and enhance Signal Noise Ratio(SNR), we set a PDR before the photo detector. The Polarization Diversity Receiver segregates the interfere light into two lights with orthogonal states of polarization. Hence, there is always one channel has a better interfere light signal. The experiments are presented to verify the effectiveness of the distributed vibration fiber sensing system proposed.

  5. Hierarchical fiber-optic delamination detection system for carbon fiber reinforced plastic structures

    Science.gov (United States)

    Minakuchi, Shu; Banshoya, Hidehiko; Shingo, Ii; Takeda, Nobuo

    2012-10-01

    This study develops a delamination detection system by extending our previous approach for monitoring surface cracks in a large-scale composite structure. In the new system, numerous thin glass capillaries are embedded into a composite structure, and internal pressure in the built-in capillary sensors, based on comparative vacuum monitoring (CVM), is maintained as a vacuum. When delamination is induced, the capillary sensors located within the delaminated area are breached, and atmospheric air flows into the capillaries. The consequent pressure change within the capillaries is then converted into axial strain in a surface-mounted optical fiber through a transducing mechanism, which is connected to the capillaries. By monitoring the strain distribution along the optical fiber, it is possible to identify a transducing mechanism in which the pressure change occurred and thus to specify the location of the delamination. This study begins by establishing a novel sensor embedding/extracting method. The airflow characteristic in the capillary sensors is then comprehensively evaluated, determining the basic performance of the new system. The proposed detection technique is validated by taking a step-by-step approach, and finally the hierarchical fiber-optic delamination detection system is demonstrated. A further advance to be combined with a self-healing concept is also discussed.

  6. Design of tension control system for fiber placement equipments

    Directory of Open Access Journals (Sweden)

    Hongjie CHANG

    2015-10-01

    Full Text Available Aiming at the tension control requirements of automatic fiber placement equipments and the problems of traditional tension control system, the hammer tension control system is designed. The hammer is used as a buffer unit in the system, and the tension can be indirectly controlled by the position of the hammer. The system adopts the motion controller as the core element of the system, the AC servo motor as the actuator and the laser position sensor as the detector. The fuzzy PID control algorithm is used for the position control of hammer, which can avoid tension fluctuation by full consideration of the acceleration of the hammer. Prototype experimental results show that this system can avoid the problems of disconnection and relaxation of fiber, meanwhile, the static difference ratio and fluctuation ratio can meet the requirements of engineering practice.

  7. Erbium - doped fiber laser systems: Routes to chaos

    Directory of Open Access Journals (Sweden)

    Rubežić Vesna

    2014-01-01

    Full Text Available Erbium-doped fiber laser systems exhibit a large variety of complex dynamical behaviors, bifurcations and attractors. In this paper, the chaotic behavior which can be achieved under certain conditions in a laser system with erbium-doped fiber, is discussed. The chaos in this system occurs through several standard scenarios. In this paper, the simulation sequence of quasiperiodic, intermittent and period-doubling scenario transitions to chaos is shown. Quasiperiodic and intermittent transitions to chaos are shown on the example system with a single ring. The electro-optical modulator was applied to the system for modulating the loss in the cavity. We used the sinusoidal and rectangular signals for modulation. Generation of chaos is achieved by changing the parameters of signal for modulation. Period-doubling transition to chaos is illustrated in a system with two rings. Simulation results are shown in the time domain and phase space.

  8. Carbon fibers: precursor systems, processing, structure, and properties.

    Science.gov (United States)

    Frank, Erik; Steudle, Lisa M; Ingildeev, Denis; Spörl, Johanna M; Buchmeiser, Michael R

    2014-05-19

    This Review gives an overview of precursor systems, their processing, and the final precursor-dependent structure of carbon fibers (CFs) including new developments in precursor systems for low-cost CFs. The following CF precursor systems are discussed: poly(acrylonitrile)-based copolymers, pitch, cellulose, lignin, poly(ethylene), and new synthetic polymeric precursors for high-end CFs. In addition, structure-property relationships and the different models for describing both the structure and morphology of CFs will be presented.

  9. Faster than fiber: over 100-Gb/s signal delivery in fiber wireless integration system.

    Science.gov (United States)

    Yu, Jianjun; Li, Xinying; Chi, Nan

    2013-09-23

    We summarize several different approaches for the realization of large capacity (>100Gb/s) fiber wireless integration system, including optical polarization-division-multiplexing (PDM) combined with multiple-input multiple-output (MIMO) reception, advanced multi-level modulation, optical multi-carrier modulation, electrical multi-carrier modulation, antenna polarization multiplexing and multi-band multiplexing. These approaches can effectively reduce the signal baud rate as well as the required bandwidth for optical and electrical devices. We also investigate the problems, such as wireless multi-path effect due to different wireless transmission distance, existing in the large capacity fiber wireless integration system. We demonstrate these problems can be effectively solved based on advanced digital-signal-processing (DSP) algorithms including classic constant modulus algorithm (CMA). Moreover, based on the combination of these approaches as well as advanced DSP algorithms, we have successfully demonstrated a 400G fiber wireless integration system, which creates a capacity record of wireless delivery and ushers in a new era of ultra-high bit rate (>400Gb/s) optical wireless integration communications at mm-wave frequencies.

  10. Fiber laser master oscillators for optical synchronization systems

    Energy Technology Data Exchange (ETDEWEB)

    Winter, A.

    2008-04-15

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  11. System response in passively phased fiber amplifier arrays

    Science.gov (United States)

    Shakir, Sami A.; Culver, Bill; Nelson, Burke; Starcher, Yuji; Bates, George M.; Hedrick, Jerry W., Jr.

    2008-08-01

    System temporal response in passively phased fiber amplifier arrays dictates how fast a passively phased system can correct for phase fluctuations due to thermal and mechanical effects. The system response time was measured by employing a variable-speed mechanical chopper in the feedback loop of a passively phased system then measuring the on-axis output intensity of the system as a function of time. Observed relaxation oscillations are compared to theory. The system response time was measured to be about 20 μsec. We also find that passive phasing improved the system's beam stability and extraction efficiency.

  12. Optical Soliton Simulation in Optical Fibers by OptiSystem

    Science.gov (United States)

    Gaik Tay, Kim; Huong Kah Ching, Audrey; Loi, Wei Sen; Tiong Ong, Chee

    2017-08-01

    Fiber optic communication is often known to offer higher frequency transmission of signals with greater bit rate and larger data carrying capacity over a long distance with lower loss and interference as compared to copper wire electrical communication. However, several factors that would affect the performance of an optical fiber transmission are such as group velocity dispersion (GVD), fiber loss and also self-phase modulation (SPM). In this paper, the effects of GVD, SPM, optical soliton formation and fiber loss are simulated using OptiSystem 14. It is found that GVD broaden pulse in temporal domain without modifying its spectrum. Meanwhile, SPM creates chirp in spectrum with its temporal profile maintained. This work concluded that a balance between the GVD and SPM is essential to form solitonthat is able to travel for a long distance without being distorted. It is also found that the decrease in the amplitude of the soliton is dependent on the fiber loss and this decay in the signal increases with the propagation distance.

  13. Fiber-Optic Micrometeoroid/Orbital Debris Impact Detector System

    Science.gov (United States)

    Christiansen, Eric L.; Tennyson, R. C.; Morison, W. D.

    2012-01-01

    A document describes a reliable, lightweight micrometeoroid/orbital debris (MMOD) detection system that can be located at strategic positions of "high consequence" to provide real-time warning of a penetration, its location, and the extent of the damage to a spacecraft. The concept is to employ fiber-optic sensors to detect impact damage and penetration of spacecraft structures. The fibers are non-electrical, employ light waves, and are immune to electromagnetic interference. The fiber-optic sensor array can be made as a stand-alone product, being bonded to a flexible membrane material or a structure that is employed as a MMOD shield material. The optical sensors can also be woven into hybrid MMOD shielding fabrics. The glass fibers of the fiber-optic sensor provide a dual purpose in contributing to the breakup of MMOD projectiles. The grid arrays can be made in a modular configuration to provide coverage over any area desired. Each module can be connected to a central scanner instrument and be interrogated in a continuous or periodic mode.

  14. Synchronous pulse generation in a multicavity fiber laser system

    Science.gov (United States)

    Gómez-Pavón, L. C.; Martí-Panameño, E.; Gómez-de la Fuente, O.; Luis-Ramos, A.

    2006-09-01

    We report the experimental synchronous pulse generation in a multicavity fiber laser system with two Erbium-doped fiber laser cavities. We have demonstrated that through the evanescent fields interaction between one cavity with active modulation and other one in continuous wave it is possible to generate more intense pulses in both cavities. Moreover, the synchronous pulse generation between cavities is achieved with an appropriate selection of pump intensity, modulation frequency and coupling ratio. We found that the pulse intensity is 2.5 times greater and the pulse duration lowers than a single Erbium-doper fiber laser. Furthermore, by means of the synchronous diagram we determined the synchronization strength in temporal pulse emission between cavities.

  15. A novel fiber audio transmission system for secure communication

    Institute of Scientific and Technical Information of China (English)

    SU Ke; JIA Bo

    2005-01-01

    A new,simple and efficient fiber audio transmission method for the long distance secure communication is presented, which performs signal modulation by the strain-optic effects and signal demodulation by the all-fiber interferometer. The interferometer is a truly path-matched device, which eliminates much of the undesirable noise by combining the reference and the sensing arms within the same optical fiber. The sinusoidal signals adopted in the experiment are in a frequency range of 300 HZ-3 400 HZ and of the multi-frequency, and the system shows good capabilities, robust security and maintenance of audio integrity. The device may be applicable in the field of point to point secure communication of 40 kilometer long transmission range.

  16. Remote (250 km Fiber Bragg Grating Multiplexing System

    Directory of Open Access Journals (Sweden)

    Manuel Lopez-Amo

    2011-09-01

    Full Text Available We propose and demonstrate two ultra-long range fiber Bragg grating (FBG sensor interrogation systems. In the first approach four FBGs are located 200 km from the monitoring station and a signal to noise ratio of 20 dB is obtained. The second improved version is able to detect the four multiplexed FBGs placed 250 km away, offering a signal to noise ratio of 6–8 dB. Consequently, this last system represents the longest range FBG sensor system reported so far that includes fiber sensor multiplexing capability. Both simple systems are based on a wavelength swept laser to scan the reflection spectra of the FBGs, and they are composed by two identical-lengths optical paths: the first one intended to launch the amplified laser signal by means of Raman amplification and the other one is employed to guide the reflection signal to the reception system.

  17. Digitalization optical open loop test system for fiber optic gyroscope

    Institute of Scientific and Technical Information of China (English)

    ZHANG Deng-wei; SHU Xiao-wu; MU Xu-dong; LIU Cheng

    2006-01-01

    In order to receive and process the open loop signal from fiber optic gyroscopes speedily,stably and expediently,and to realize the amity interface between human and machine,a digital system that can convert GPIB (general purpose interface bus ) parallel bus into Universal Serial Bus is developed.All the interface functions of GP1B and the hardware system are realized through FPGA.With a digital sampling and processing system designed with VC++ in Windows platform,the real-time controlling procedure,high-speed receiving and sending data can be carried out,and the results can be displayed too.So the design of the system is flexible,the reliability and the stability are improved,error rate is no more than 10-11,the highest bit rate is 8 MB/s and the open loop detection system for optic fiber gyros achieves standardization and complete digitalization simultaneously.

  18. Fiber-Based Ultraviolet Laser System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this program is to develop a compact and efficient ultraviolet laser system for use in space-based uv-Raman instruments. The basis for this system...

  19. Non-overlapped random decrement technique for parameter identification in operational modal analysis

    Science.gov (United States)

    Zhang, Y.; Song, H. W.

    2016-03-01

    The random decrement technique (RDT) is used to estimate free vibration response from output data generated by Gaussian white noise. The principle is to decay the excitation via averaging of segments in output data. With RDT, the triggering condition for determining the initial points of segments causes overlap during averaging; the consequence is a residual excitation, peaking at the first natural frequency. This paper presents a modified RDT with non-overlapped segments to eliminate this peak. Numerical comparison between non-overlapped RDT (NRDT) and RDT shows the accuracy improvement of damping. However, time history data is sometimes not long enough in NRDT, which results in an inevitable overlap. In order to keep the accuracy of NRDT, the first natural period is viewed as the critical length between adjacent initial points to distinguish the inevitable overlap from that in RDT.

  20. Computationally Efficient Nonlinearity Compensation for Coherent Fiber-Optic Systems

    Institute of Scientific and Technical Information of China (English)

    Likai Zhu; Guifang Li

    2012-01-01

    Split-step digital backward propagation (DBP) can be combined with coherent detection to compensate for fiber nonlinear impairments. A large number of DBP steps is usually needed for a long-haul fiber system, and this creates a heavy computational load. In a trade-off between complexity and performance, interchannel nonlinearity can be disregarded in order to simplify the DBP algorithm. The number of steps can also be reduced at the expense of performance. In periodic dispersion-managed long-haul transmission systems, optical waveform distortion is dominated by chromatic dispersion. As a result, the nonlinearity of the optical signal repeats in every dispersion period. Because of this periodic behavior, DBP of many fiber spans can be folded into one span. Using this distance-folded DBP method, the required computation for a transoceanic transmission system with full inline dispersion compensation can be reduced by up to two orders of magnitude with negligible penalty. The folded DBP method can be modified to compensate for nonlinearity in fiber links with non-zero residua dispersion per span.

  1. Routing Protection Scheme For Redundancy In Fiber Communication Systems

    Science.gov (United States)

    Werthman, Dean A.; Corke, Michael; Fitzgerald, Paul W.

    1990-01-01

    Redundancy in communication systems is vital for providing customer satisfaction and a cost effective network. If a line is cut in present systems, the traffic on that line must be routed to other channels while an emergency repair is made. If the operating company cannot provide the bandwidth to satisfy this rerouting, it must rent information capacity from its competitors. Presently, fiber is being installed in the metropolitan and subscriber loop networks, and consideration is being taken to provide redundancy in network reconfiguration to reduce fiber breakage problems. In a full duplex communication network, individual optical waveguides are utilized for transmission and reception of signals. Figure 1 illustrates a typical metropolitan network link from office to office. If a cable is severed by accident during construction work, discontinuity of service would result. When there are thousands of premium-paying customers at the other end of that cable, this situation can achieve crisis level immediately. In this paper details of a route protection or diversification scheme will be presented that will incorporate an intelligent fiber optic system that will automatically detect a cable fault and switch traffic to redundant fiber cables.

  2. High-stability polymer optical fiber with Rhodamine-doped cladding for fiber light systems

    Science.gov (United States)

    Jaramillo-Ochoa, L.; Narro-García, R.; Ocampo, M. A.; Quintero-Torres, R.

    2016-09-01

    In this work, the photodegradation of a polymer optical fiber with Rhodamine doped cladding as a function of illumination time and excitation intensity is presented. To show the effect of photodegradation on different bulk geometries and environments, the photodegradation from a dye doped preform and a PMMA thick film is also evaluated. The reversible and the irreversible degradation of the florescent material were quantified under an established excitation scheme. To this purpose, a four-level system to model the photodegradation rates and its relation with the population of the states is presented and it is used to justify a possible underlying mechanism. The obtained results suggest an increase of one order of magnitude in the stability (lifetime) of the polymer optical fiber with respect to the preform or the thick film geometry stability.

  3. Numerical analysis of intermodal delay in few-mode fibers for mode division multiplexing in optical fiber communication systems

    Institute of Scientific and Technical Information of China (English)

    Abid Munir; XIN Xiang-jun; LIU Bo; Abdul Latif; Aftab Hussain; Shahab Ahmad Niazi

    2012-01-01

    In order to achieve higher spectral efficiency,mode division multiplexing (MDM) in few-mode fibers is a new research area.The idea faces lots of technical issues including intermodal delay and mode coupling which limit the achievable length of the system.This paper is designated to complete the analysis of intermodal delay in step-index few-mode fibers.We analyze numerically all the parameters of fiber,which could impact intermodal delay in few-mode fibers and identify the conditions which can increase the number of multiplex modes without significant increase in maximum intermodal delay.

  4. Fiber-optic liquid level monitoring system using microstructured polymer fiber Bragg grating array sensors: performance analysis

    DEFF Research Database (Denmark)

    Marques, C. A. F.; Pospori, A.; Saez-Rodriguez, D.

    2015-01-01

    A highly sensitive liquid level monitoring system based on microstructured polymer optical fiber Bragg grating (mPOFBG) array sensors is reported for the first time. The configuration is based on five mPOFBGs inscribed in the same fiber in the 850 nm spectral region, showing the potential to inte...

  5. 1Gbps impulse radio ultrawideband multi-hop system employing a single mode fiber repeater

    DEFF Research Database (Denmark)

    Yu, Xianbin; Rodes, Roberto; Jensen, Jesper Bevensee;

    2009-01-01

    We experimentally demonstrate a 1 Gbps impulse radio ultrawideband multi-hop system for wireless-over-fiber applications. The system consists of two 2 m air links and a 23 km single mode fiber based optical repeater......We experimentally demonstrate a 1 Gbps impulse radio ultrawideband multi-hop system for wireless-over-fiber applications. The system consists of two 2 m air links and a 23 km single mode fiber based optical repeater...

  6. Fiber-array based optogenetic prosthetic system for stimulation therapy

    Science.gov (United States)

    Gu, Ling; Cote, Chris; Tejeda, Hector; Mohanty, Samarendra

    2012-02-01

    Recent advent of optogenetics has enabled activation of genetically-targeted neuronal cells using low intensity blue light with high temporal precision. Since blue light is attenuated rapidly due to scattering and absorption in neural tissue, optogenetic treatment of neurological disorders may require stimulation of specific cell types in multiple regions of the brain. Further, restoration of certain neural functions (vision, and auditory etc) requires accurate spatio-temporal stimulation patterns rather than just precise temporal stimulation. In order to activate multiple regions of the central nervous system in 3D, here, we report development of an optogenetic prosthetic comprising of array of fibers coupled to independently-controllable LEDs. This design avoids direct contact of LEDs with the brain tissue and thus does not require electrical and heat isolation, which can non-specifically stimulate and damage the local brain regions. The intensity, frequency, and duty cycle of light pulses from each fiber in the array was controlled independently using an inhouse developed LabView based program interfaced with a microcontroller driving the individual LEDs. While the temporal profile of the light pulses was controlled by varying the current driving the LED, the beam profile emanating from each fiber tip could be sculpted by microfabrication of the fiber tip. The fiber array was used to stimulate neurons, expressing channelrhodopsin-2, in different locations within the brain or retina. Control of neural activity in the mice cortex, using the fiber-array based prosthetic, is evaluated from recordings made with multi-electrode array (MEA). We also report construction of a μLED array based prosthetic for spatio-temporal stimulation of cortex.

  7. 78 FR 17187 - Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems Technology...

    Science.gov (United States)

    2013-03-20

    ... Department of the Navy Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems... to grant to Fiber Optic Sensor Systems Technology Corporation, a revocable, nonassignable, exclusive... its intent to grant to Fiber Optic Sensor Systems Technology Corporation a revocable, nonassignable...

  8. Components for monolithic fiber chirped pulse amplification laser systems

    Science.gov (United States)

    Swan, Michael Craig

    The first portion of this work develops techniques for generating femtosecond-pulses from conventional fabry-perot laser diodes using nonlinear-spectral-broadening techniques in Yb-doped positive dispersion fiber ampliers. The approach employed an injection-locked fabry-perot laser diode followed by two stages of nonlinear-spectral-broadening to generate sub-200fs pulses. This thesis demonstrated that a 60ps gain-switched fabry-perot laser-diode can be injection-locked to generate a single-longitudinal-mode pulse and compressed by nonlinear spectral broadening to 4ps. Two problems have been identified that must be resolved before moving forward with this approach. First, gain-switched pulses from a standard diode-laser have a number of characteristics not well suited for producing clean self-phase-modulation-broadened pulses, such as an asymmetric temporal shape, which has a long pulse tail. Second, though parabolic pulse formation occurs for any arbitrary temporal input pulse profile, deviation from the optimum parabolic input results in extensively spectrally modulated self-phase-modulation-broadened pulses. In conclusion, the approach of generating self-phase-modulation-broadened pulses from pulsed laser diodes has to be modified from the initial approach explored in this thesis. The first Yb-doped chirally-coupled-core ber based systems are demonstrated and characterized in the second portion of this work. Robust single-mode performance independent of excitation or any other external mode management techniques have been demonstrated in Yb-doped chirally-coupled-core fibers. Gain and power efficiency characteristics are not compromised in any way in this novel fiber structure up to the 87W maximum power achieved. Both the small signal gain at 1064nm of 30.3dB, and the wavelength dependence of the small signal gain were comparable to currently deployed large-mode-area-fiber technology. The efficiencies of the laser and amplifier were measured to be 75% and 54

  9. Bidirectional fiber-wireless and fiber-IVLLC integrated system based on polarization-orthogonal modulation scheme.

    Science.gov (United States)

    Lu, Hai-Han; Li, Chung-Yi; Chen, Hwan-Wei; Ho, Chun-Ming; Cheng, Ming-Te; Huang, Sheng-Jhe; Yang, Zih-Yi; Lin, Xin-Yao

    2016-07-25

    A bidirectional fiber-wireless and fiber-invisible laser light communication (IVLLC) integrated system that employs polarization-orthogonal modulation scheme for hybrid cable television (CATV)/microwave (MW)/millimeter-wave (MMW)/baseband (BB) signal transmission is proposed and demonstrated. To our knowledge, it is the first one that adopts a polarization-orthogonal modulation scheme in a bidirectional fiber-wireless and fiber-IVLLC integrated system with hybrid CATV/MW/MMW/BB signal. For downlink transmission, carrier-to-noise ratio (CNR), composite second-order (CSO), composite triple-beat (CTB), and bit error rate (BER) perform well over 40-km single-mode fiber (SMF) and 10-m RF/50-m optical wireless transport scenarios. For uplink transmission, good BER performance is obtained over 40-km SMF and 50-m optical wireless transport scenario. Such a bidirectional fiber-wireless and fiber-IVLLC integrated system for hybrid CATV/MW/MMW/BB signal transmission will be an attractive alternative for providing broadband integrated services, including CATV, Internet, and telecommunication services. It is shown to be a prominent one to present the advancements for the convergence of fiber backbone and RF/optical wireless feeder.

  10. Nondestructive thickness measurement system for multiple layers of paint based on femtosecond fiber laser technologies

    Science.gov (United States)

    Sudo, Masaaki; Takayanagi, Jun; Ohtake, Hideyuki

    2016-11-01

    Because optical fiber-based optical systems are generally robust against external interference, they can be used as reliable systems in industrial applications in various fields. This paper describes fiber lasers generating femtosecond pulses that use optical fibers as gain media and optical paths. Additionally, the nondestructive paint multilayer thickness measurement of automotive parts using terahertz waves generated and detected by femtosecond fiber laser systems was conducted.

  11. Muscular condition monitoring system using fiber bragg grating sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Heon Young; Lee, Jin Hyuk; Kim, Dae Hyun [Seoul National University of Technology, Seoul (Korea, Republic of)

    2014-10-15

    Fiber optic sensors (FOS) have advantages such as electromagnetic interference (EMI) immunity, corrosion resistance and multiplexing capability. For these reasons, they are widely used in various condition monitoring systems (CMS). This study investigated a muscular condition monitoring system using fiber optic sensors (FOS). Generally, sensors for monitoring the condition of the human body are based on electro-magnetic devices. However, such an electrical system has several weaknesses, including the potential for electro-magnetic interference and distortion. Fiber Bragg grating (FBG) sensors overcome these weaknesses, along with simplifying the devices and increasing user convenience. To measure the level of muscle contraction and relaxation, which indicates the muscle condition, a belt-shaped FBG sensor module that makes it possible to monitor the movement of muscles in the radial and circumferential directions was fabricated in this study. In addition, a uniaxial tensile test was carried out in order to evaluate the applicability of this FBG sensor module. Based on the experimental results, a relationship was observed between the tensile stress and Bragg wavelength of the FBG sensors, which revealed the possibility of fabricating a muscular condition monitoring system based on FBG sensors.

  12. Dispersion compensation of fiber Bragg gratings in 3100 km high speed optical fiber transmission system

    Institute of Scientific and Technical Information of China (English)

    Li PEI; Tigang NING; Fengping YAN; Xiaowei DONG; Zhongwei TAN; Yan LIU; Shuisheng JIAN

    2009-01-01

    By optimizing the fabrication process of the chirped optical fiber Bragg grating (CFBG), some key problems of CFBG are solved, such as fabrication repetition, temperature stability, group delay ripple (GDR), fluctuation of the reflection spectrum, polarization mode dispersion (PMD), interaction of cascaded CFBG, and so on. The CFBG we fabricated can attain a temperature coefficient less than 0.0005 nm/℃, and the smoothed GDR and the fluctuation of the reflection spectrum are smaller than 10ps and 0.5dB, respec-tively. The PMD of each CFBG is less than 1 ps and the dispersion of each grating is larger than -2600 ps/(nm·km). With dispersion compensated by the CFBGs we fabricated, a 13×10 Gbit/s 3100 km ultra long G.652 fiber transmission system is successfully imple-mented without electric regenerator. The bit error rate (BER) of the system is below 10-4 without forward error correction (FEC); when FEC is added, the BER is below 10-12. The power penalty of the carrier-suppressed return-to-zero (CSRZ) code transmission system is only 2.5 dB.

  13. A New Idea and Technique of Fiber Gratings and Photodetectors in Broad-band Fiber Communication Systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Contents of this thesis are supported by the National Natural Foudation of China under Contract No.69625101, and the item is named “Tunable Optical Technology in Wavelength Division Multiplexing (WDM)” and is under charge of Professor Ren Xiaomin. They are also supported by subject 307 in National Program “863”: i.e., RCE photodetectors (PDs) used in Wavelength Division Multiplexing. Fiber Bragg Gratings (FBGs) have emerged as important optical fiber passive components in a variety of light-wave applications. It is expected that FBGs will play a key role in the next generation of optical fiber communication systems and sensor fileds. Most of these applications are based on the narrow-band reflection of FBGs. In this thesis, transmission dispersion, nonlinearity and tunability of FBGs are studied. The main contents are as follows: Transmission dispersion of FBGs is studied and the capability of dispersion compensation of FBGs is calculated theoretically. In the experiments, the dispersions of 10 Gb/s at 11.1 km and 22.22 km are compensated successfully by an unchirped fiber grating for the first time in China and the tunable compensation is achieved for the first time internationally. The scheme of tunable dispersion compensation using cascaded fiber gratings in WDM is analyzed and designed. It is indicated that the dispersion compensation in transmission using uniform fiber gratings is a better and more effective compensation scheme compared with the tradifitonal dispersion compensation using chirped fiber gratings. It is originally proposed that people can simulate characteristics of a long distance optical fiber by a short uniform fiber grating. This is verified for the first time experimentally. In the experiment, a short grating (about 1 cm) operated in transmission is used to simulate pulse broadening of 11.1 km optical fiber. This method can be used to detect performance of long distance transmission of communication systems. It is originally proposed

  14. Evaluation of a simplified fiber post removal system.

    Science.gov (United States)

    Scotti, Nicola; Bergantin, Emanuele; Alovisi, Mario; Pasqualini, Damiano; Berutti, Elio

    2013-11-01

    This study investigated the influence of clinical experience in relation to the efficacy and effectiveness of removal of 2 different fiber posts. In total, 48 intact single-rooted teeth were treated endodontically and obturated. Then, 10-mm post spaces were prepared, and fiber posts were luted. Twenty-four #1 D.T. Light-Posts were used in group 1, and 24 #2 Hi-Rem Prosthetic Posts were used in group 2. A pullout test (n = 8 per group) was performed by using a universal testing machine to compare bond strength. Then, fiber post removal efficacy and efficiency were tested. Each group was divided into 2 subgroups (n = 8) according to operator experience. In group 1, fiber posts were removed with an ultrasonic handpiece by using a #3 Start-X tip. In group 2, a size 25/0.04 ProFile was used to remove the central soft polymer macrofiber, and a #2 Largo drill was used to remove the fiber post and luting cement remnants. Post removal times were recorded to evaluate efficacy. Weight change was determined, and post space walls were analyzed microscopically to evaluate effectiveness. Bond strength did not differ significantly (P = .7569) between post systems. Post hoc Tukey tests indicated that removal time was affected significantly by operator experience in group 1 (P < .001) but not in group 2. Weight change was affected significantly by experience level in both groups. No difference in post space wall characteristics was observed between subgroups. The Hi-Rem post was easier to remove than the D.T Light-Post. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. A Transformer Partial Discharge Measurement System Based on Fluorescent Fiber

    Directory of Open Access Journals (Sweden)

    Fan Liu

    2012-05-01

    Full Text Available Based on the physical phenomena of optical effects produced by the partial discharge (PD and on the characteristics of fluorescent fiber sensing of weak fluorescent signals, a PD measurement system using a fluorescent fiber sensor was designed. The main parameters of the sensing system were calculated, an experimental testing platform for PD simulation in the lab was established, and PD signals were then detected through ultra-high frequency (UHF and optical methods under a needle-plate discharge model. PD optical pulses in transformer oil contained signal-peak and multi-peak pulse waveforms. Compared with UHF detection results, the number of PD pulses and the elapsed PD pulse phase time revealed a good corresponding relationship. However, PD signal amplitudes presented the opposite, thus indicating that PD UHF signals reflected pulse amplitude value, whereas PD optical signals reflected pulse energy magnitude. The n-u-φ three-dimensional distributions indicated that most of the PD signals concentrated in the nearby industrial frequency voltage peak value. Overall, the proposed fluorescent fiber sensing system design can be used successfully in transformer PD signal detection.

  16. 75 FR 34988 - Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems Technology...

    Science.gov (United States)

    2010-06-21

    ... Department of the Navy Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems... Navy hereby gives notice of its intent to grant to Fiber Optic Sensor Systems Technology Corporation a.... Patent No. 7,149,374: Fiber Optic Pressure Sensor, Navy Case No. 84,557.//U.S. Patent No. 7,379,630...

  17. 77 FR 73456 - Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems Technology...

    Science.gov (United States)

    2012-12-10

    ... Department of the Navy Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems... Navy hereby gives notice of its intent to grant to Fiber Optic Sensor Systems Technology Corporation a... described in U.S. Patent No. 7,020,354: Intensity Modulated Fiber Optic Pressure Sensor, Navy Case No. 83...

  18. Development of Touch Probing System Using a Fiber Stylus

    Directory of Open Access Journals (Sweden)

    Hiroshi Murakami

    2016-08-01

    Full Text Available This paper presents a system that can be used for micro-hole measurement; the system comprises an optical fiber stylus that is 5 µm in diameter. The stylus deflects when it comes into contact with the measured surface; this deflection is measured optically. In this study, the design parameters of the optical system are determined using a ray-tracing method, and a prototype of the probing system is fabricated to verify ray-tracing simulation results; furthermore, the performance of the system is evaluated experimentally. The results show that the design parameters of this system can be determined using ray-tracing; the resolution of the measurement system using this shaft was approximately 3 nm, and the practicality of this system was confirmed by measuring the shape of a micro-hole 100 µm in diameter and 475 µm in depth.

  19. Sensing delamination in epoxy encapsulant systems with fiber Bragg gratings

    Science.gov (United States)

    Jones, Brad H.; Rohr, Garth D.; Kaczmarowski, Amy K.

    2016-05-01

    Fiber Bragg gratings (FBGs) are well-suited for embedded sensing of interfacial phenomena in materials systems, due to the sensitivity of their spectral response to locally non-uniform strain fields. Over the last 15 years, FBGs have been successfully employed to sense delamination at interfaces, with a clear emphasis on planar events induced by transverse cracks in fiber-reinforced plastic laminates. We have built upon this work by utilizing FBGs to detect circular delamination events at the interface between epoxy films and alumina substrates. Two different delamination processes are examined, based on stress relief induced by indentation of the epoxy film or by cooling to low temperature. We have characterized the spectral response pre- and post-delamination for both simple and chirped FBGs as a function of delamination size. We show that delamination is readily detected by the evolution of a non-uniform strain distribution along the fiber axis that persists after the stressing condition is removed. These residual strain distributions differ substantially between the delamination processes, with indentation and cooling producing predominantly tensile and compressive strain, respectively, that are well-captured by Gaussian profiles. More importantly, we observe a strong correlation between spectrally-derived measurements, such as spectral widths, and delamination size. Our results further highlight the unique capabilities of FBGs as diagnostic tools for sensing delamination in materials systems.

  20. Fiber optical parametric amplifiers in optical communication systems

    DEFF Research Database (Denmark)

    Marhic, Michel E.; Andrekson, Peter A.; Petropoulos, Periklis

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-...... in excess of 14,000 Tb/s x km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed.......The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time......-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512Gb/s have been transmitted over 6,000km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products...

  1. Test Stability of Uster Advanced Fiber Information System(AFIS)

    Institute of Scientific and Technical Information of China (English)

    CAO Ji-peng; LU Qin; SUN Peng-zi; LIU Hua-pu

    2010-01-01

    To study test stability of Advanced Fiber Information System(AFIS),card sliver produced in two experiments(12 plans in each experiment)were tested by AFIS.By a statistic analysis of the test results,the number of test times that can get a reliable test reliability(hereinafter this number of test times is referred to as Reliable Test Times,RTT)of test parameters and the coefficient of variation(CV%)values of 30 test results of each experiment plan were obtained.It's concluded that some parameters,such as length,seed coat nep(SCN)size,nep size and immature fiber content(IFC),etc. are very reliable by a test of ten or more times,but other parameters,such as SCN content,trash content,and visible foreign matter(VFM)content,etc.are not reliable until they are tested over 100 times.

  2. Design of distributed Raman temperature sensing system based on single-mode optical fiber

    Institute of Scientific and Technical Information of China (English)

    Ziheng XU; Deming LIU; Hairong LIU; Qizhen SUN; Zhifeng SUN; Xu ZHANG; Wengang WANG

    2009-01-01

    The distributed optical fiber temperature sensor system based on Raman scattering has developed rapidly since it was invented in 1970s. The optical wavelengths used in most of the distributed temperature optical fiber sensor system based on the Raman scattering are around from 840 to 1330 nm, and the system operates with multimode optical fibers. However, this wavelength range is not suitable for long-distance transmission due to the high attenuation and dispersion of the transmission optical fiber. A novel distributed optical fiber Raman temperature sensor system based on standard single-mode optical fiber is proposed. The system employs the wavelength of 1550 nm as the probe light and the standard communication optical fiber as the sensing medium to increase the sensing distance. This system mainly includes three modules: the probe light transmitting module, the light magnifying and transmission module, and the signal acquisition module.

  3. Study on a transient optical fiber high temperature measurement system

    Science.gov (United States)

    Cai, Lulu; Liu, Yusha; Wang, Yutian

    2009-07-01

    High temperature is one of the most important parameters in the fields of scientific research and industrial production. At present, thermocouple, thermo resistive and radiance thermometer are already technologically mature which can be adopted to measure the general temperature, but when it comes to the transient high temperature that changes pretty quickly in wretched conditions, those traditional pyrometers can not meet the requirements any more. In this paper, we designed a transient optical high temperature measurement system. First, design of the temperature measurement probe. The system took blackbody cavity sensor together with optical fiber to receive the measured signal, here, the integrated emissivity model of the blackbody cavity was established and the optimum structure parameters were confirmed. Secondly, design of the entire temperature measurement system. A contact-noncontact measurement method was applied, which is to make the blackbody cavity and the measured high-temperature source contact, the fiber probe and the blackbody cavity noncontact, as a result, the error caused by contact measurement is overcame and the precision is guaranteed at the same time. In addition, a fiber grating was introduced as the wavelength filter device which can realize the dynamic filter of narrow-band signals and reduce the impact of background light. Thirdly, signal processing. In this part, we applied labVIEW software and wavelet analysis method. All of the signal acquisition and processing were realized in the labVIEW environment. Through calling matlab in labVIEW, the signals from optical fiber detector were wavelet denoised and decomposed, thus the temperature information was extracted, and the temperature value was obtained. On basis of wavelet transformation, the paper adopted the 4dB wavelet with horizontal scale of 5 to realize the feature extraction and noise removal, parts of the signals before and after the wavelet noise removal were given and analyzed

  4. VARIANCE OF NONLINEAR PHASE NOISE IN FIBER-OPTIC SYSTEM

    Directory of Open Access Journals (Sweden)

    RANJU KANWAR

    2013-04-01

    Full Text Available In communication system, the noise process must be known, in order to compute the system performance. The nonlinear effects act as strong perturbation in long- haul system. This perturbation effects the signal, when interact with amplitude noise, and results in random motion of the phase of the signal. Based on the perturbation theory, the variance of nonlinear phase noise contaminated by both self- and cross-phase modulation, is derived analytically for phase-shift- keying system. Through this work, it is investigated that for longer transmission distance, 40-Gb/s systems are more sensitive to nonlinear phase noise as compared to 50-Gb/s systems. Also, when transmitting the data through the fiber optic link, bit errors are produced due to various effects such as noise from optical amplifiers and nonlinearity occurring in fiber. On the basis of the simulation results , we have compared the bit error rate based on 8-PSK with theoretical results, and result shows that in real time approach, the bit error rate is high for the same signal to noise ratio. MATLAB software is used to validate the analytical expressions for the variance of nonlinear phase noise.

  5. Galvanometer beam-scanning system for laser fiber drawing.

    Science.gov (United States)

    Oehrle, R C

    1979-02-15

    A major difficulty in using a laser to draw optical fibers from a glass preform has been uniformally distributing the laser's energy around the melt zone. Several systems have evolved in recent years, but to date the most successful technique has been the off-axis rotating lens system (RLS). The inability of this device to structure efficiently and dynamically the heat zone longitudinally along the preform has restricted its use to preform of less than 8-mm diameter. A new technique reported here employs two orthogonal mounted mirrors, driven by galvanometers to distribute the laser energy around the preform. This system can be retrofitted into the RLS to replace the rotating lens element. The new system, the galvanometer scanning system (GSS), operates at ten times the rotational speed of the RLS and can instantaneously modify the melt zone. The ability of the GSS to enlarge the melt zone reduces the vaporization rate at the surface of the preform permitting efficient use of higher laser power. Experiments i dicate that fibers can be drawn from significantly larger preforms by using the expanded heat zone provided by the GSS.

  6. Smart Wireless System in Fiber to the Home

    Directory of Open Access Journals (Sweden)

    Kamarulzaman Mat

    2012-01-01

    Full Text Available Problem statement: Fiber To The Home (FTTH is optical network that plays an important role to carry multimedia service to customers. The failure service caused by fiber optic cut or device malfunction always happens and it cannot be avoided. Approach: To solve the failure efficiently and effectively, it is needed a real time monitoring system that can work automatically to detect the failure and perform restoration. Smart wireless system is built to perform this task. It can monitor the optical signal continuously and perform restoration fast. Tapping method is used to take a small part of optical signal that goes to customers. This small amount of optical signal will be processed by converter and microcontroller for monitoring and restoration purpose. Results: Based on our experiment, the best coefficient coupler in this system is 0.1 with the receiver sensitivity 32 dBm. This system also is capable to detect the amplitude of video signal synchronous by real time. Conclusion: The proposed system is the first, reported up to this time using RF signal to monitor the optical signal and perform automatic restoration.

  7. Oxidation of carbon fiber surfaces for use as reinforcement in high-temperature cementitious material systems

    Science.gov (United States)

    Sugama, Toshifumi

    1990-01-01

    The interfacial bond characteristics between carbon fiber and a cement matrix, in high temperature fiber-reinforced cementitious composite systems, can be improved by the oxidative treatment of the fiber surfaces. Compositions and the process for producing the compositions are disclosed.

  8. High-Spatial-Multiplicity Multicore Fibers for Future Dense Space-Division-Multiplexing Systems

    DEFF Research Database (Denmark)

    Matsuo, Shoichiro; Takenaga, Katsuhiro; Sasaki, Yusuke;

    2016-01-01

    Multicore fibers and few-mode fibers have potential application in realizing dense-space-division multiplexing systems. However, there are some tradeoff requirements for designing the fibers. In this paper, the tradeoff requirements such as spatial channel count, crosstalk, differential mode dela...

  9. Perceived Non-Overlap of Objects in an Audiovisual Stream/Bounce Display

    Directory of Open Access Journals (Sweden)

    Yousuke Kawachi

    2011-10-01

    Full Text Available In a stream/bounce display in which two identical visual objects move toward each other, coincide (completely overlap, and then move apart, the objects can be perceived as either streaming through or bouncing off each other. Despite the perceptual ambiguity in this display, the streaming percept is dominant. However, a sound burst presented at the time that the objects coincide facilitates the bouncing percept. Herein, we report a perceptual phenomenon in which the overlap between objects is illusorily perceived as a non-overlap in the stream/bounce display accompanied with sound. In the experiment, the amount of overlap between two objects was systematically manipulated in the presence/absence of a sound. Observers were asked to judge whether the two objects overlapped with each other and then asked whether the objects appeared to stream through or bounce off each other. The results were consistent with those of previous studies showing that sound promoted the bouncing percept. Most importantly, the sound presentation facilitated the perception of a non-overlap between the objects instead of a physical overlap, suggesting that the momentary overlap was inadequately perceived. We discuss the possibility that an abrupt sound temporally interrupts visual processing such as the formation of dynamic object representations.

  10. Design of a Very Small Residual Dispersion Fiber System for DWDM Operation Over the Entire C - & L- Bands of EDFA

    Institute of Scientific and Technical Information of China (English)

    Ravi K.Varshney; I.C.Goyal; A.K.Ghatak; Siny Antony C.

    2003-01-01

    We have given design of a very small residual dispersion fiber system consisting of a small dispersion fiber(SDF) with flat modal field and a corresponding dual core coaxial dispersion compensating fiber (DCF).

  11. Route-asymmetrical light transmission of a fiber-chip-fiber optomechanical system

    DEFF Research Database (Denmark)

    Liu, Li; Ding, Yunhong; Cai, Xinlun;

    2016-01-01

    In this paper, we proposed and experimentally demonstrated a route-asymmetrical light transmission scheme based on the thermal radiative effect, which means that forward and backward propagations of an optical device have different transmittances provided they are not present simultaneously......-wave (CW) light but also 10 Gbit/s on-off-keying (OOK) digital signals. Above mentioned unique features can be mostly attributed to the significant characteristics of the thermal radiative effect, which could cause a fiber displacement up to tens of microns. The powerful and significant thermal radiative...... effect opens up a new opportunity and method for route-asymmetrical light transmission. Moreover, this research may have important applications in all-optical systems, such as the optical limiters and ultra-low loss switches....

  12. Chaos synchronization characteristics in erbium-doped fiber laser systems

    Science.gov (United States)

    Imai, Y.; Murakawa, H.; Imoto, T.

    2003-03-01

    Chaos synchronization characteristics in the master-slave and slave-slave systems with modulated erbium-doped fiber lasers are investigated numerically. We find that synchronization state of chaos becomes better, i.e., the correlation coefficient between the two outputs reaches unity, as the difference in the input power between the two subsystems decreases and is not dependent strongly upon the difference in the modulation index in both the master-slave and slave-slave systems. In the master-slave system, the highest correlation coefficient is attained at the smaller pump power and the larger modulation index in the slave subsystem than those in the master subsystem. On the other hand, the correlation coefficient equal to unity is achieved with the identical parameters in the slave 1 and 2 subsystems in the slave-slave system.

  13. Method and system for aligning fibers during electrospinning

    Science.gov (United States)

    Scott-Carnell, Lisa A. (Inventor); Stephens, Ralph M (Inventor); Holloway, Nancy M. (Inventor); Rhim, Caroline (Inventor); Niklason, Laura (Inventor); Clark, Robert L. (Inventor); Siochi, Emilie J. (Inventor)

    2011-01-01

    A method and system are provided for aligning fibers in an electrospinning process. A jet of a fiberizable material is directed towards an uncharged collector from a dispensing location that is spaced apart from the collector. While the fiberizable material is directed towards the collector, an elliptical electric field is generated via the electrically charged dispenser and an oppositely-charged control location. The field spans between the dispensing location and the control location that is within line-of-sight of the dispensing location, and impinges upon at least a portion of the collector. Various combinations of numbers and geometries of dispensers, collectors, and electrodes can be used.

  14. Dynamic gate algorithm for multimode fiber Bragg grating sensor systems

    DEFF Research Database (Denmark)

    Ganziy, Denis; Jespersen, O.; Woyessa, Getinet

    2015-01-01

    We propose a novel dynamic gate algorithm (DGA) for precise and accurate peak detection. The algorithm uses a threshold-determined detection window and center of gravity algorithm with bias compensation. We analyze the wavelength fit resolution of the DGA for different values of the signal......-to-noise ratio and different peak shapes. Our simulations and experiments demonstrate that the DGA method is fast and robust with better stability and accuracy than conventional algorithms. This makes it very attractive for future implementation in sensing systems, especially based on multimode fiber Bragg...

  15. Recrystallization behaviour of CaO-MgO-SiO{sub 2} system ceramic fibers

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xitang; Zhang Baoguo [Hubei Province Key Lab. of Ceramics and Refractories, Wuhan Univ. of Science and Technology, Wuhan (China)

    2007-07-01

    Various kinds of ceramic fibers are used in industries for thermal insulation. Traditional Al{sub 2}O{sub 3}-SiO{sub 2} refractory ceramic fibers have potential health hazard when they come into the lung of human beings. The bio-soluble ceramic fibers in CaO-MgO-SiO{sub 2} system, as a new group of synthetic glass fibers, have been developed recently for high-temperature insulation applications. The fibers were specially designed to have high solubility and hence low bio-durability in human body lung solution. Various calcium magnesium silicate bio-soluble glass fibers are produced at present to replace aluminium silicate ceramic fibers. In practical applications such as fiber lining of various kinds of high temperature furnace or kiln, devitrification of the fibers take place and consequently fiber surface become rougher. Formation and growth of crystal phases could cause the destruction and pulverization of the fibers after a long exposure at high temperature. For traditional Al{sub 2}O{sub 3}-SiO{sub 2} refractory ceramic fibers the recrystallization temperature of the fibers starts at 980 C with the formation of mullite and cristobalite phases. Comparing with Al{sub 2}O{sub 3}-SiO{sub 2} ceramic fibers, the relatively lower application temperature of CaO-MgO-SiO{sub 2} system bio-soluble fibers is considered. In this paper, the studies were focused on recrystallization behaviour of CaO-MgO-SiO{sub 2} system soluble ceramic fibers. (orig.)

  16. Sensing system with Michelson-type fiber optical interferometer based on single FBG reflector

    Institute of Scientific and Technical Information of China (English)

    Xueliang Zhang; Zhou Meng; Zhengliang Hu

    2011-01-01

    A sensing system, with Michelson-type fiber optical interferometer based on single fiber Bragg grating (FBG) as the reflector, is demonstrated. The system used a frequency-matched ring fiber optical laser as the source. The closed Michelson-type fiber optical interferometer system will be helpful in simplifying the developed interferometric sensor by replacing the double reflectors with only one FBG reflecting the double-side light. The basic sensing properties of the system are demonstrated, with a fiber optic piezoelectric ceramic transducer embedded in the arm of the interferometer simulating the sensing signal.%As a simple fiber optic component,fiber Bragg grating (FBG) has been used frequently as a sensor,filter or reflector[1-4],etc.Meanwhile,the Michelson-type fiber optical interferometric sensor has achieved a high level of development in the acoustic,electric,and magnetic field sensors because of its simple and low-cost structure as well as multiplexing advantages.The Michelsontype interferometer has been widely applied with Faraday rotating mirrors (FRMs) or polarization maintaining fiber reflectors particularly in the fiber optic hydrophone system[5,6].At present,further research is aimed at simplifying fiber optical interferometric sensors.

  17. Optical generation of millimeter-wave pulses using a fiber Bragg grating in a fiber-optics system.

    Science.gov (United States)

    Ye, Qing; Qu, Ronghui; Fang, Zujie

    2007-04-10

    A scheme is proposed to transform an optical pulse into a millimeter-wave frequency modulation pulse by using a weak fiber Bragg grating (FBG) in a fiber-optics system. The Fourier transformation method is used to obtain the required spectrum response function of the FBG for the Gaussian pulse, soliton pulse, and Lorenz shape pulse. On the condition of the first-order Born approximation of the weak fiber grating, the relation of the refractive index distribution and the spectrum response function of the FBG satisfies the Fourier transformation, and the corresponding refractive index distribution forms are obtained for single-frequency modulation and linear-frequency modulation millimeter-wave pulse generation. The performances of the designed fiber gratings are also studied by a numerical simulation method for a supershort pulse transmission.

  18. Impact of fiber ring laser configuration on detection capabilities in FBG based sensor systems

    Science.gov (United States)

    Osuch, Tomasz; Kossek, Tomasz; Markowski, Konrad

    2014-11-01

    In this paper fiber ring lasers (FRL) as interrogation units for distributed fiber Bragg grating (FBG) based sensor networks are studied. In particular, two configurations of the fiber laser with erbium-doped fiber amplifier (EDFA) and semiconductor optical amplifier (SOA) as gain medium were analyzed. In the case of EDFA-based fiber interrogation systems, CW as well as active-mode locking operation were taken into account. The influence of spectral overlapping of FBGs spectra on detection capabilities of examined FRLs are presented. Experimental results show that the SOA-based fiber laser interrogation unit can operate as a multi-parametric sensing system. In turn, using an actively mode-locked fiber ring laser with an EDFA, an electronically switchable FBG based sensing system can be realized.

  19. Modeling of a Single Multimode Fiber Imaging System

    CERN Document Server

    Liu, Chen; Liu, Deming; Su, Lei

    2016-01-01

    We present a detailed theoretical analysis on image transmission via a single multimode fiber (MMF). A single MMF imaging model is developed to study the light wave propagation from the light source to the camera, by using free-space Fourier optics theory and mode-coupling theory. A mathematical expression is obtained for the complete single MMF imaging system, which is further validated by image-transmission simulations. Our model is believed to be the first theoretical model to describe the complete MMF imaging system based on the transmission of individual modes. Therefore, this model is robust and capable of analyzing MMF image transmission under specific mode-coupling conditions. We use our model to study bending-induced image blur in single-MMF image transmission, and the result has found a good agreement with that of existing experimental studies. These should provide important insights into future MMF imaging system developments.

  20. Optimizing power efficiency in radio-over-fiber systems

    DEFF Research Database (Denmark)

    Koonen, A. M. J.; Popov, M.; Wessing, Henrik

    2013-01-01

    Fiber-fed radio pico-cells topologies can reduce the overall power consumption of wireless communication networks. Joint optimization of fiber and radio network parts yields an optimum number of pico-cells which minimizes power consumption.......Fiber-fed radio pico-cells topologies can reduce the overall power consumption of wireless communication networks. Joint optimization of fiber and radio network parts yields an optimum number of pico-cells which minimizes power consumption....

  1. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Included among...

  2. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Among the...

  3. Spectral characterization and discrimination of synthetic fibers with near-infrared hyperspectral imaging system.

    Science.gov (United States)

    Jin, Xiaoke; Memon, Hafeezullah; Tian, Wei; Yin, Qinli; Zhan, Xiaofang; Zhu, Chengyan

    2017-04-20

    Synthetic fibers account for about half of all fiber usage, with applications in every textile field. The phenomenon of fiber composition not matching the label harms consumer interests and impedes market development. Hyperspectral imaging technology as a potential technique can be utilized to discriminate mass synthetic fibers rapidly and nondestructively and achieves the functions that traditional Fourier transform infrared instruments do not have. On the basis of investigating the impact of dope-dyeing and wrapping processes on spectra, the spectral features (from 900 to 2500 nm) of six categories of synthetic fibers were extracted with a hyperspectral imaging system. A principal component analysis-linear discriminant analysis model was developed to discriminate the chemical content of fibers in different colors and structures, which showed 100% discrimination accuracy. Results demonstrated the feasibility of a hyperspectral imaging system in synthetic fiber discrimination. Therefore, this method offers a more convenient alternative for textile industry on-site discrimination.

  4. On the convergence rate of a parallel nonoverlapping domain decomposition method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In recent years,a nonoverlapping domain decomposition iterative procedure,which is based on using Robin-type boundary conditions as information transmission conditions on the subdomain interfaces,has been developed and analyzed.It is known that the convergence rate of this method is 1-O(h),where h is mesh size.In this paper,the convergence rate is improved to be 1-O(h1/2 H-1/2)sometime by choosing suitable parameter,where H is the subdomain size.Counter examples are constructed to show that our convergence estimates are sharp,which means that the convergence rate cannot be better than 1-O(h1/2H-1/2)in a certain case no matter how parameter is chosen.

  5. Dynamic Principal Component Analysis with Nonoverlapping Moving Window and Its Applications to Epileptic EEG Classification

    Directory of Open Access Journals (Sweden)

    Shengkun Xie

    2014-01-01

    Full Text Available Classification of electroencephalography (EEG is the most useful diagnostic and monitoring procedure for epilepsy study. A reliable algorithm that can be easily implemented is the key to this procedure. In this paper a novel signal feature extraction method based on dynamic principal component analysis and nonoverlapping moving window is proposed. Along with this new technique, two detection methods based on extracted sparse features are applied to deal with signal classification. The obtained results demonstrated that our proposed methodologies are able to differentiate EEGs from controls and interictal for epilepsy diagnosis and to separate EEGs from interictal and ictal for seizure detection. Our approach yields high classification accuracy for both single-channel short-term EEGs and multichannel long-term EEGs. The classification performance of the method is also compared with other state-of-the-art techniques on the same datasets and the effect of signal variability on the presented methods is also studied.

  6. Dynamic principal component analysis with nonoverlapping moving window and its applications to epileptic EEG classification.

    Science.gov (United States)

    Xie, Shengkun; Krishnan, Sridhar

    2014-01-01

    Classification of electroencephalography (EEG) is the most useful diagnostic and monitoring procedure for epilepsy study. A reliable algorithm that can be easily implemented is the key to this procedure. In this paper a novel signal feature extraction method based on dynamic principal component analysis and nonoverlapping moving window is proposed. Along with this new technique, two detection methods based on extracted sparse features are applied to deal with signal classification. The obtained results demonstrated that our proposed methodologies are able to differentiate EEGs from controls and interictal for epilepsy diagnosis and to separate EEGs from interictal and ictal for seizure detection. Our approach yields high classification accuracy for both single-channel short-term EEGs and multichannel long-term EEGs. The classification performance of the method is also compared with other state-of-the-art techniques on the same datasets and the effect of signal variability on the presented methods is also studied.

  7. On the convergence rate of a parallel nonoverlapping domain decomposition method

    Institute of Scientific and Technical Information of China (English)

    QIN LiZhen; SHI ZhongCi; XU XueJun

    2008-01-01

    In recent years, a nonoverlapping domain decomposition iterative procedure, which is based on using Robin-type boundary conditions as information transmission conditions on the subdomain interfaces, has been developed and analyzed. It is known that the convergence rate of this method is 1 - O(h), where h is mesh size. In this paper, the convergence rate is improved to be 1 - O(h1/2H-1/2) sometime by choosing suitable parameter, where H is the subdomain size. Counter examples are constructed to show that our convergence estimates are sharp, which means that the convergence rate cannot be better than 1 - O(h1/2H-1/2) in a certain case no matter how parameter is chosen.

  8. Beam shaping design for compact and high-brightness fiber-coupled laser-diode system.

    Science.gov (United States)

    Yu, Junhong; Guo, Linui; Wu, Hualing; Wang, Zhao; Tan, Hao; Gao, Songxin; Wu, Deyong; Zhang, Kai

    2015-06-20

    Fiber-coupled laser diodes have become essential sources for fiber laser pumping and direct energy applications. A compact and high-brightness fiber-coupled system has been designed based on a significant beam shaping method. The laser-diode stack consists of eight mini-bars and is effectively coupled into a standard 100 μm core diameter and NA=0.22 fiber. The simulative result indicates that the module will have an output power over 440 W. Using this technique, compactness and high-brightness production of a fiber-coupled laser-diode module is possible.

  9. Research on vision-based error detection system for optic fiber winding

    Science.gov (United States)

    Lu, Wenchao; Li, Huipeng; Yang, Dewei; Zhang, Min

    2011-11-01

    Optic fiber coils are the hearts of fiber optic gyroscopes (FOGs). To detect the irresistible errors during the process of winding of optical fibers, such as gaps, climbs and partial rises between fibers, when fiber optic winding machines are operated, and to enable fully automated winding, we researched and designed this vision-based error detection system for optic fiber winding, on the basis of digital image collection and process[1]. When a Fiber-optic winding machine is operated, background light is used as illumination system to strength the contrast of images between fibers and background. Then microscope and CCD as imaging system and image collecting system are used to receive the analog images of fibers. After that analog images are shifted into digital imagines, which can be processed and analyzed by computers. Canny edge detection and a contour-tracing algorithm are used as the main image processing method. The distances between the fiber peaks were then measured and compared with the desired values. If these values fall outside of a predetermined tolerance zone, an error is detected and classified either as a gap, climb or rise. we used OpenCV and MATLAB database as basic function library and used VC++6.0 as the platform to show the results. The test results showed that the system was useful, and the edge detection and contour-tracing algorithm were effective, because of the high rate of accuracy. At the same time, the results of error detection are correct.

  10. Plastic optical fiber serial communications link for distributed control system

    Science.gov (United States)

    Saxena, Piyush; Sharangpani, K. K.; Vora, H. S.; Nakhe, S. V.; Jain, R.; Shenoy, N. M.; Bhatnagar, R.; Shirke, N. D.

    2001-09-01

    One of the most common interface for communications specified is RS 232C standard. Though widely accepted, RS232 has limited transmission speed, range and networking capabilities. RS 422 standard overcomes limitations by using differential signal lines. In automation of the operation of gas discharge lasers, multiple processors are used for control of lasers, cooling system, vacuum system etc. High EMI generated by lasers interfere through galvanic transmission or by radiation over the length of cables, and hang up operation of processors or control PC. A serial communications link was designed eliminating copper transmission media, using plastic optical fiber cables and components, to connect local controllers with the master PC working on RS232 protocols. The paper discusses the design and implementation of a high ly reliable EMI harden serial communications link.

  11. Overview of advanced components for fiber optic systems

    Science.gov (United States)

    Depaula, Ramon P.; Stowe, David W.

    1986-01-01

    The basic operating principles and potential performance of several state-of-the-art fiber-optic devices are illustrated with diagrams and briefly characterized. Technologies examined include high-birefringence polarization-maintaining fibers and directional couplers, single-mode fiber polarizers and cut-off polarizers, optical-fiber modulators with radially poled piezoactive polymer (PVF2) jackets, and piezoelectric-squeezer polarization modulators. The need for improved manufacturing techniques to make such fiber-optic devices cost-competitive with their thin-film integrated-optics analogs is indicated.

  12. Fiber optical parametric amplifiers in optical communication systems.

    Science.gov (United States)

    Marhic, Michel E; Andrekson, Peter A; Petropoulos, Periklis; Radic, Stojan; Peucheret, Christophe; Jazayerifar, Mahmoud

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. [Formula: see text].

  13. Relationship between isthmotectal fibers and other tectopetal systems in the leopard frog.

    Science.gov (United States)

    Gruberg, E R; Wallace, M T; Waldeck, R F

    1989-10-01

    We studied the relationship of isthmotectal input to other tectal afferent fiber systems in three ways. 1) Using horseradish peroxidase (HRP) histochemistry, we determined the nonretinal inputs to the superficial tectum. In different sets of animals we a) applied HRP to the tectal surface; b) inserted HRP crystals into the tectum; c) injected small volumes of HRP solutions into the superficial tectum. N. isthmi accounts for more than 65% of the nonretinal extrinsic input in the superficial tectal layers. One set of fibers from the contralateral n. isthmi projects to the most superficial layer. Fibers from posterior thalamus and tegmentum project to both superficial and deeper layers in the tectum, but not to the most superficial layer. The ipsilaterally projecting isthmotectal fibers terminate in the deeper superficial layers. 2) We investigated the relationship between retinofugal and contralaterally projecting isthmotectal pathways. We orthogradely labelled n. isthmi fibers by unilateral HRP injections into n. isthmi, and we also labelled retinal fibers by injecting tritiated l-proline into both eyes. In such animals contralaterally projecting isthmotectal fibers cross in the dorsal posterior region of the optic chiasm. From the chiasm to the tectum isthmotectal fibers and retinofugal fibers are admixed. 3) We determined whether other fiber systems cross with contralaterally projecting isthmotectal fibers. We cut the posterior part of the optic chiasm and applied HRP crystals to the cut. Only n. isthmi and retina are retrogradely labelled.

  14. Near-infrared fiber delivery systems for interstitial photothermal therapy

    Science.gov (United States)

    Slatkine, Michael; Mead, Douglass S.; Konwitz, Eli; Rosenberg, Zvi

    1995-05-01

    Interstitial photothermal coagulation has long been recognized as a potential important, minimally invasive modality for treating a variety of pathologic conditions. We present two different technologies for interstitial photothermal coagulation of tissue with infrared lasers: An optical fiber with a radially symmetric diffusing tip for deep coagulation, and a flat bare fiber for the coagulation of thin and long lesions by longitudinally moving the fiber while lasing in concert. Urology and Gynecology Fibers: The fibers are 600 microns diameter with 20 - 40 mm frosted distal tips protected by a smooth transparent cover. When used with a Neodymium:YAG (Nd:YAG) laser, the active fiber surface diffuses optical radiation in a radial pattern, delivering up to 40 W power, and thus providing consistent and uniform interstitial photothermal therapy. Coagulation depth ranges from 4 to 15 mm. Animal studies in the United States and clinical studies in Europe have demonstrated the feasibility of using these fibers to treat benign prostatic hyperplasia and endometrial coagulation. Rhinology Fiber: The fiber is an 800 micron diameter flat fiber operated at 8 W power level while being interstitially pushed and pulled along its axis. A long and thin coagulated zone is produced. The fiber is routinely used for the shrinking of hypertrophic turbinates without surrounding and bone mucusal damage in ambulatory environments.

  15. A distributed fiber optic sensor system for dike monitoring using Brillouin optical frequency domain analysis

    Science.gov (United States)

    Nöther, Nils; Wosniok, Aleksander; Krebber, Katerina; Thiele, Elke

    2008-03-01

    We report on the development of a complete system for spatially resolved detection of critical soil displacement in river embankments. The system uses Brillouin frequency domain analysis (BOFDA) for distributed measurement of strain in silica optical fibers. Our development consists of the measurement unit, an adequate coating for the optical fibers and a technique to integrate the coated optical fibers into geotextiles as they are commonly used in dike construction. We present several laboratory and field tests that prove the capability of the system to detect areas of soil displacement as small as 2 meters. These are the first tests of truly distributed strain measurements on optical fibers embedded into geosynthetics.

  16. Femtosecond coherent seeding of a broadband Tm:fiber amplifier by an Er:fiber system.

    Science.gov (United States)

    Kumkar, Sören; Krauss, Günther; Wunram, Marcel; Fehrenbacher, David; Demirbas, Umit; Brida, Daniele; Leitenstorfer, Alfred

    2012-02-15

    We generate broadband pulses covering the Yb: and Tm:silica amplification ranges with a passively phase-locked front end based on Er:fiber technology. Full spectral coherence of the octave-spanning output from highly nonlinear germanosilicate bulk fibers is demonstrated. Seeding of a high-power Tm:fiber generates pulses with a clean spectral shape and a bandwidth of 50 nm at a center wavelength of 1.95 μm, pulse energy of 250 nJ, and repetition rate of 10 MHz.

  17. Fiber

    Science.gov (United States)

    ... ON THIS TOPIC Healthy Dining Hall Eating Smart Supermarket Shopping Organic and Other Environmentally Friendly Foods Vegan Food Guide Food Labels Digestive System Smart Snacking Constipation Contact Us Print Resources Send ...

  18. Study of superhydrophobic electrospun nanocomposite fibers for energy systems.

    Science.gov (United States)

    Asmatulu, Ramazan; Ceylan, Muhammet; Nuraje, Nurxat

    2011-01-18

    Polystyrene (PS) and polyvinyl chloride (PVC) fibers incorporated into TiO(2) nanoparticles and graphene nanoflakes were fabricated by an electrospinning technique, and then the surface morphology and superhydrophobicity of these electrospun nanocomposite fibers were investigated. Results indicated that the water contact angle of the nanocomposite fiber surfaces increases to 178° on the basis of the fiber diameter, material type, nanoscale inclusion, heat treatment, and surface porosity/roughness. This is a result of the formation of the Cassie-Baxter state in the fibers via the nanoparticle decoration, bead formation, and surface energy of the nanofiber surface. Consequently, these superhydrophobic nanocomposite fibers can be utilized in designing photoelectrodes of dye-sensitized solar cells (DSSCs) as self-cleaning and anti-icing materials for the long-term efficiency of the cells.

  19. Tunable Laser Development for In-flight Fiber Optic Based Structural Health Monitoring Systems

    Science.gov (United States)

    Richards, Lance; Parker, Allen; Chan, Patrick

    2014-01-01

    The objective of this task is to investigate, develop, and demonstrate a low-cost swept lasing light source for NASA DFRC's fiber optics sensing system (FOSS) to perform structural health monitoring on current and future aerospace vehicles. This is the regular update of the Tunable Laser Development for In-flight Fiber Optic Based Structural Health Monitoring Systems website.

  20. Fiber-optic liquid level monitoring system using microstructured polymer fiber Bragg grating array sensors: performance analysis

    DEFF Research Database (Denmark)

    Marques, C. A. F.; Pospori, A.; Saez-Rodriguez, D.;

    2015-01-01

    to interrogate liquid level by measuring the strain induced in each mPOFBG embedded in a silicone rubber (SR) diaphragm, which deforms due to hydrostatic pressure variations. The sensor exhibits a highly linear response over the sensing range, a good repeatability, and a high resolution. The sensitivity......A highly sensitive liquid level monitoring system based on microstructured polymer optical fiber Bragg grating (mPOFBG) array sensors is reported for the first time. The configuration is based on five mPOFBGs inscribed in the same fiber in the 850 nm spectral region, showing the potential...... of the sensor is found to be 98 pm/cm of water, enhanced by more than a factor of 9 when compared to an equivalent sensor based on a silica fiber around 1550 nm. The temperature sensitivity is studied and a multi-sensor arrangement proposed, which has the potential to provide level readings independent...

  1. Ultra-broadband indoor optical wireless communication system with multimode fiber.

    Science.gov (United States)

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2012-05-01

    In this paper we experimentally demonstrate an ultra-broadband indoor full-duplex WDM optical wireless communication system with multimode fiber. The multimode fiber is used because it is employed in most of the already installed in-building fiber distribution networks. Simultaneous error-free (BERfiber will induce ~2.4 cm reduction in the maximum error-free beam footprint in the downlink, the bit rate of the uplink can be much higher compared to the system with single-mode fiber.

  2. Complex bioactive fiber systems by means of electrospinning

    OpenAIRE

    2010-01-01

    Nanofibrous mats are interesting scaffold materials for biomedical applications like tissue engineering due to their interconnectivity and their size dimension which mimics the native cell environment. Electrospinning provides a simple route to access such fiber meshes. This thesis addresses the structural and functional control of electrospun fiber mats. In the first section, it is shown that fiber meshes with bimodal size distribution could be obtained in a single-step process by electrospi...

  3. Compound Tension Control of an Optical-Fiber Coil System: A Cyber-Physical System View

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2014-03-01

    Full Text Available The full-automatic optical-fiber coil winding equipment is a complex electromechanical system which contains signal acquisition, data processing, communications, and motor control. In the complex electromechanical system, the subsystems rely on wired or wireless network technology to complete the real-time perception, coordinate, accurate, and dynamitic control, and information exchange services. The paper points to the full-automatic optical-fiber coil winding equipment with the characteristics of cyber-physical system to research its numerical design. We present a novel compound tension control system based on the experimental platform dSPACE to achieve semiphysical simulation of compound tension control system and examine the functions of control system.

  4. Innovative fiber coating systems based on organic modified ceramics

    Science.gov (United States)

    Schuster, Kay; Kobelke, Jens; Rose, Klaus; Helbig, Manfred; Zoheidi, Mohammad; Heinze, Alexander

    2010-02-01

    We describe the application of inorganic organic hybrid materials (ORMOCERs) as optical fiber coatings for use in Fiber Bragg Grating sensors and high power transmission fibers. The materials are UV curable, enable a single layer thickness of about 50 μm and show high a high peak temperature stability >300 °C. Regarding the fiber protection the coatings have been investigated using tensile strength measurements before and after temperature load. Best coatings maintain the high tensile strength of 68 N (125 μm fiber) with a Weibull parameter of 182 after a temperature cycling up to 300 °C. For the first time a low refractive index ORMOCER will be presented showing a numerical aperture of 0.47 at a wavelength of 1000 nm on a pure silica fiber. This corresponds to a refractive index of 1.37. The fiber possesses a fiber loss of 18 dB/km at a wavelength of 1000 nm. The fibers have been coated using a gravity as well as pressure technology. The latter possesses extremely minimized die equipment and is therefore well applicable for small coating amounts. The so called dead volume within the coating die is about 1 ml. The overall dead volume is only influenced by the supply pipe and can be reduced down to 5 ml.

  5. Cable television monitoring system based on fiber laser and FBG sensor

    Science.gov (United States)

    Peng, Peng-Chun; Huang, Jun-Han; Wu, Shin-Shian; Yang, Wei-Yuan; Shen, Po-Tso

    2015-05-01

    We propose and experimentally demonstrate a cable television monitoring system based on a linear-cavity fiber laser and fiber Bragg grating (FBG) sensors. The linear-cavity fiber laser comprises a hybrid amplifier with an erbium-doped fiber amplifier and a semiconductor optical amplifier, a fiber loop mirror with a polarization controller and an optical coupler as a cavity mirror, and the FBG sensors acting as another cavity mirrors. Experimental results showed the feasibility of the monitoring system with sufficient of signal-to-noise ratio over 30 dB and stable output power, and the link of cable television signals on fiber link can monitored in real time. Excellent performances of carrier-to-noise ratio after long-distance transmission are obtained for cable television applications.

  6. Hole-assisted multicore optical fiber for next generation telecom transmission systems

    Science.gov (United States)

    Ziolowicz, A.; Szymanski, M.; Szostkiewicz, L.; Tenderenda, T.; Napierala, M.; Murawski, M.; Holdynski, Z.; Ostrowski, L.; Mergo, P.; Poturaj, K.; Makara, M.; Slowikowski, M.; Pawlik, K.; Stanczyk, T.; Stepien, K.; Wysokinski, K.; Broczkowska, M.; Nasilowski, T.

    2014-08-01

    We present a multicore fiber dedicated for next generation transmission systems. To overcome the issue of multicore fibers' integration with existing transmission systems, the fiber is designed in such a way that the transmission parameters for each core (i.e., chromatic dispersion, attenuation, bending loss, etc.) are in total accordance with the obligatory standards for telecommunication single core fibers (i.e., ITU-T G.652 and G.657). We show the results of numerical investigations and measurements carried out for the fabricated fiber, which confirm low core-to-core crosstalk and compatibility with standard single-core single-mode transmission links making the fiber ready for implementation in the near future.

  7. A Flexible Fiber-Based Supercapacitor-Triboelectric-Nanogenerator Power System for Wearable Electronics.

    Science.gov (United States)

    Wang, Jie; Li, Xiuhan; Zi, Yunlong; Wang, Sihong; Li, Zhaoling; Zheng, Li; Yi, Fang; Li, Shengming; Wang, Zhong Lin

    2015-09-02

    A flexible self-charging power system is built by integrating a fiber-based supercapacitor with a fiber-based triboelectric nanogenerator for harvesting mechanical energy from human motion. The fiber-based supercapacitor exhibits outstanding electrochemical properties, owing to the excellent pseudocapacitance of well-prepared RuO2 ·xH2 O by a vapor-phase hydrothermal method as the active material. The approach is a step forward toward self-powered wearable electronics.

  8. Analysis and Derivation of Allocations for Fiber Contaminants in Liquid Bipropellant Systems

    Science.gov (United States)

    Lowrey, N. M; ibrahim, K. Y.

    2012-01-01

    An analysis was performed to identify the engineering rationale for the existing particulate limits in MSFC-SPEC-164, Cleanliness of Components for Use in Oxygen, Fuel, and Pneumatic Systems, determine the applicability of this rationale to fibers, identify potential risks that may result from fiber contamination in liquid oxygen/fuel bipropellant systems, and bound each of these risks. The objective of this analysis was to determine whether fiber contamination exceeding the established quantitative limits for particulate can be tolerated in these systems and, if so, to derive and recommend quantitative allocations for fibers beyond the limits established for other particulate. Knowledge gaps were identified that limit a complete understanding of the risk of promoted ignition from an accumulation of fibers in a gaseous oxygen system.

  9. Optical System Monitoring Based on Reflection Spectrum of Fiber Bragg Grating

    Directory of Open Access Journals (Sweden)

    Mastang Tanra

    2012-01-01

    Full Text Available Problem statement: This study presents fiber fault monitoring approaches for Fiber-to-the Home (FTTH with a Passive Optical Network (PON. Current fiber fault monitoring approaches are difficult to be implemented due to its complexity and high loss as the amount of branches increase. Approach: A fiber fault monitoring scheme is proposed whereas Fiber Bragg Grating (FBG is placed on each branch of the Optical Network Unit (ONU. The advantages of the scheme are that it is simple, low cost and efficient in monitoring fiber fault in ONU. FTTH based network design is simulated using Optisystemtem 8.0 in order to investigate the feasibility of the proposed scheme. Results: The reflection spectrum of Fiber Bragg Gratings (FBGs with different spectrum shape, frequencies and amplitude is used to differentiate each optical network. The simulation result shows that the unique characteristic of fiber Bragg grating is able to distinguish each optical network for a 20 km Passive Optical Network (PON system. Conclusion: This study suggests the implementation of Fiber Bragg Grating that is placed in each network instead of using Optical Time Domain Reflectometer (OTDR for fiber fault monitoring.

  10. Configuring compute nodes of a parallel computer in an operational group into a plurality of independent non-overlapping collective networks

    Science.gov (United States)

    Archer, Charles J.; Inglett, Todd A.; Ratterman, Joseph D.; Smith, Brian E.

    2010-03-02

    Methods, apparatus, and products are disclosed for configuring compute nodes of a parallel computer in an operational group into a plurality of independent non-overlapping collective networks, the compute nodes in the operational group connected together for data communications through a global combining network, that include: partitioning the compute nodes in the operational group into a plurality of non-overlapping subgroups; designating one compute node from each of the non-overlapping subgroups as a master node; and assigning, to the compute nodes in each of the non-overlapping subgroups, class routing instructions that organize the compute nodes in that non-overlapping subgroup as a collective network such that the master node is a physical root.

  11. A fiber Bragg based semi distributed pressure sensor system for in-vivo vascular applications

    NARCIS (Netherlands)

    Nieuwland, R.A.; Cheng, L.K.; Lemmen, M.H.J.; Oostenbrink, R.H.; Harmsma, P.J.; Schreuder, J.J.

    2014-01-01

    An overview of a fiber Bragg based sensor system, developed for in-vivo vascular pressure and temperature sensing, is presented. The focus is on sensor miniaturization and interrogator optimization to reach a viable sensor system.

  12. An All-Fiber-Optic Combined System of Noncontact Photoacoustic Tomography and Optical Coherence Tomography.

    Science.gov (United States)

    Eom, Jonghyun; Shin, Jun Geun; Park, Soongho; Rim, Sunghwan; Lee, Byeong Ha

    2016-05-20

    We propose an all-fiber-based dual-modal imaging system that combines noncontact photoacoustic tomography (PAT) and optical coherence tomography (OCT). The PAT remotely measures photoacoustic (PA) signals with a 1550-nm laser on the surface of a sample by utilizing a fiber interferometer as an ultrasound detector. The fiber-based OCT, employing a swept-source laser centered at 1310 nm, shares the sample arm of the PAT system. The fiber-optic probe for the combined system was homemade with a lensed single-mode fiber (SMF) and a large-core multimode fiber (MMF). The compact and robust common probe is capable of obtaining both the PA and the OCT signals at the same position without any physical contact. Additionally, the MMF of the probe delivers the short pulses of a Nd:YAG laser to efficiently excite the PA signals. We experimentally demonstrate the feasibility of the proposed dual-modal system with a phantom made of a fishing line and a black polyethylene terephthalate fiber in a tissue mimicking solution. The all-fiber-optic system, capable of providing complementary information about absorption and scattering, has a promising potential in minimally invasive and endoscopic imaging.

  13. A method for identification and analysis of non-overlapping myeloid immunophenotypes in humans.

    Directory of Open Access Journals (Sweden)

    Michael P Gustafson

    Full Text Available The development of flow cytometric biomarkers in human studies and clinical trials has been slowed by inconsistent sample processing, use of cell surface markers, and reporting of immunophenotypes. Additionally, the function(s of distinct cell types as biomarkers cannot be accurately defined without the proper identification of homogeneous populations. As such, we developed a method for the identification and analysis of human leukocyte populations by the use of eight 10-color flow cytometric protocols in combination with novel software analyses. This method utilizes un-manipulated biological sample preparation that allows for the direct quantitation of leukocytes and non-overlapping immunophenotypes. We specifically designed myeloid protocols that enable us to define distinct phenotypes that include mature monocytes, granulocytes, circulating dendritic cells, immature myeloid cells, and myeloid derived suppressor cells (MDSCs. We also identified CD123 as an additional distinguishing marker for the phenotypic characterization of immature LIN-CD33+HLA-DR- MDSCs. Our approach permits the comprehensive analysis of all peripheral blood leukocytes and yields data that is highly amenable for standardization across inter-laboratory comparisons for human studies.

  14. Nonoverlapping Clinical and Mutational Patterns in Melanomas from the Female Genital Tract and Atypical Genital Nevi.

    Science.gov (United States)

    Yélamos, Oriol; Merkel, Emily A; Sholl, Lauren Meldi; Zhang, Bin; Amin, Sapna M; Lee, Christina Y; Guitart, Gerta E; Yang, Jingyi; Wenzel, Alexander T; Bunick, Christopher G; Yazdan, Pedram; Choi, Jaehyuk; Gerami, Pedram

    2016-09-01

    Genital melanomas (GM) are the second most common cancer of the female external genitalia and may be confused with atypical genital nevi (AGN), which exhibit atypical histological features but have benign behavior. In this study, we compared the clinical, histological, and molecular features of 19 GM and 25 AGN. We described chromosomal copy number aberrations and the mutational status of 50 oncogenes and tumor suppressor genes in both groups. Our study showed that a pigmented lesion occurring in mucosal tissue, particularly in postmenopausal women, was more likely to be a melanoma than a nevus. GM had high levels of chromosomal instability, with many copy number aberrations. Furthermore, we found a completely nonoverlapping pattern of oncogenic mutations when comparing GM and AGN. In GM, we report somatic mutations in KIT and TP53. Conversely, AGN had frequent BRAF V600E mutations, which were not seen in any of the GM. Our results show that GM and AGN have distinct clinical and molecular changes and that GM have a different mutational pattern compared with AGN.

  15. Overlapping and non-overlapping functions of condensins I and II in neural stem cell divisions.

    Directory of Open Access Journals (Sweden)

    Kenji Nishide

    2014-12-01

    Full Text Available During development of the cerebral cortex, neural stem cells (NSCs divide symmetrically to proliferate and asymmetrically to generate neurons. Although faithful segregation of mitotic chromosomes is critical for NSC divisions, its fundamental mechanism remains unclear. A class of evolutionarily conserved protein complexes, known as condensins, is thought to be central to chromosome assembly and segregation among eukaryotes. Here we report the first comprehensive genetic study of mammalian condensins, demonstrating that two different types of condensin complexes (condensins I and II are both essential for NSC divisions and survival in mice. Simultaneous depletion of both condensins leads to severe defects in chromosome assembly and segregation, which in turn cause DNA damage and trigger p53-induced apoptosis. Individual depletions of condensins I and II lead to slower loss of NSCs compared to simultaneous depletion, but they display distinct mitotic defects: chromosome missegregation was observed more prominently in NSCs depleted of condensin II, whereas mitotic delays were detectable only in condensin I-depleted NSCs. Remarkably, NSCs depleted of condensin II display hyperclustering of pericentric heterochromatin and nucleoli, indicating that condensin II, but not condensin I, plays a critical role in establishing interphase nuclear architecture. Intriguingly, these defects are taken over to postmitotic neurons. Our results demonstrate that condensins I and II have overlapping and non-overlapping functions in NSCs, and also provide evolutionary insight into intricate balancing acts of the two condensin complexes.

  16. Extrinsic calibration of a non-overlapping camera network based on close-range photogrammetry.

    Science.gov (United States)

    Dong, Shuai; Shao, Xinxing; Kang, Xin; Yang, Fujun; He, Xiaoyuan

    2016-08-10

    In this paper, an extrinsic calibration method for a non-overlapping camera network is presented based on close-range photogrammetry. The method does not require calibration targets or the cameras to be moved. The visual sensors are relatively motionless and do not see the same area at the same time. The proposed method combines the multiple cameras using some arbitrarily distributed encoded targets. The calibration procedure consists of three steps: reconstructing the three-dimensional (3D) coordinates of the encoded targets using a hand-held digital camera, performing the intrinsic calibration of the camera network, and calibrating the extrinsic parameters of each camera with only one image. A series of experiments, including 3D reconstruction, rotation, and translation, are employed to validate the proposed approach. The results show that the relative error for the 3D reconstruction is smaller than 0.003%, the relative errors of both rotation and translation are less than 0.066%, and the re-projection error is only 0.09 pixels.

  17. Filament-wound vessel from an organic fiber-epoxy system.

    Science.gov (United States)

    Chiao, T. T.; Marcon, M. A.

    1973-01-01

    We evaluated the PRD-49-III fiber by winding 4-in. vessels in an epoxy matrix. From over 130 vessels of various designs, the best average vessel performance factor (PV/W) based on fiber was 2,500,000 in.; based on the composite it was 1,800,000 in. The highest average fiber-failure stress was 446 ksi. It is evident that for shell structures that involve minimal shear loading this fiber/epoxy material system is indeed very attractive.

  18. Measurement of creep of optical fiber by a low coherent white light double interferometer system

    Institute of Scientific and Technical Information of China (English)

    Farhad; ANSARI

    2009-01-01

    The creep properties of optical fiber used in fiber optical sensors were studied in this paper. A low co- herent white light double interferometer system was designed and calibrated and the creep deforma- tions of optical fibers under static and cyclic loadings were measured with this device. The research results showed that polymer coated optical fibers crept at the beginning when they were under static or cyclic load. As the number of the cyclic loading or the static loading times increased the creep tended to stop. Thus to ensure that the optical fiber keeps pre-stress for long time in pressure transducer, it is recommended that the optical fiber should be tensioned cyclically before being fixed into the sensor device.

  19. Measurement of creep of optical fiber by a low coherent white light double interferometer system

    Institute of Scientific and Technical Information of China (English)

    XU ZhiHong; Farhad ANSARI

    2009-01-01

    The creep properties of optical fiber used in fiber optical sensors were studied in this paper. A low co-herent white light double interferometer system was designed and calibrated and the creep deforma-tions of optical fibers under static and cyclic Ioadings were measured with this device. The research results showed that polymer coated optical fibers crept at the beginning when they were under static or cyclic load. As the number of the cyclic loading or the static loading times increased the creep tended to stop. Thus to ensure that the optical fiber keeps pro-stress for long time in pressure transducer, it is recommended that the optical fiber should be tensioned cyclically before being fixed into the sensor device.

  20. Multi-core Fibers in Submarine Networks for High-Capacity Undersea Transmission Systems

    DEFF Research Database (Denmark)

    Nooruzzaman, Md; Morioka, Toshio

    2017-01-01

    Application of multi-core fibers in undersea networks for high-capacity submarine transmission systems is studied. It is demonstrated how different architectures of submerged branching unit affect network component counts in long-haul undersea transmission systems......Application of multi-core fibers in undersea networks for high-capacity submarine transmission systems is studied. It is demonstrated how different architectures of submerged branching unit affect network component counts in long-haul undersea transmission systems...

  1. Design optical antenna and fiber coupling system based on the vector theory of reflection and refraction.

    Science.gov (United States)

    Jiang, Ping; Yang, Huajun; Mao, Shengqian

    2015-10-05

    A Cassegrain antenna system and an optical fiber coupling system which consists of a plano-concave lens and a plano-convex lens are designed based on the vector theory of reflection and refraction, so as to improve the transmission performance of the optical antenna and fiber coupling system. Three-dimensional ray tracing simulation are performed and results of the optical aberrations calculation and the experimental test show that the aberrations caused by on-axial defocusing, off-axial defocusing and deflection of receiving antenna can be well corrected by the optical fiber coupling system.

  2. Application research on hydraulic coke cutting monitoring system based on optical fiber sensing technology

    Science.gov (United States)

    Zhong, Dong; Tong, Xinglin

    2014-06-01

    With the development of the optical fiber sensing technology, the acoustic emission sensor has become one of the focal research topics. On the basis of studying the traditional hydraulic coke cutting monitoring system, the optical fiber acoustic emission sensor has been applied in the hydraulic coke cutting monitoring system for the first time, researching the monitoring signal of the optical fiber acoustic emission sensor in the system. The actual test results show that using the acoustic emission sensor in the hydraulic coke cutting monitoring system can get the real-time and accurate hydraulic coke cutting state and the effective realization of hydraulic coke cutting automatic monitoring in the Wuhan Branch of Sinopec.

  3. Fiber optic/cone penetrometer system for subsurface heavy metals detection

    Energy Technology Data Exchange (ETDEWEB)

    Saggese, S.; Greenwell, R. [Science & Engineering Associates, Inc., San Diego, CA (United States)

    1995-10-01

    The objective of this project is to develop an integrated fiber optic sensor/cone penetrometer system to analyze the heavy metals content of the subsurface. This site characterization tool will use an optical fiber cable assembly which delivers high power laser energy to vaporize and excite a sample in-situ and return the emission spectrum from the plasma produced for chemical analysis. The chemical analysis technique, often referred to as laser induced breakdown spectroscopy (LIBS), has recently shown to be an effective method for the quantitative analysis of contaminants soils. By integrating the fiber optic sensor with the cone penetrometer, we anticipate that the resultant system will enable in-situ, low cost, high resolution, real-time subsurface characterization of numerous heavy metal soil contaminants simultaneously. There are several challenges associated with the integration of the LIBS sensor and cone penetrometer. One challenge is to design an effective means of optically accessing the soil via the fiber probe in the penetrometer. A second challenge is to develop the fiber probe system such that the resultant emission signal is adequate for quantitative analysis. Laboratory techniques typically use free space delivery of the laser to the sample. The high laser powers used in the laboratory cannot be used with optical fibers, therefore, the effectiveness of the LIBS system at the laser powers acceptable to fiber delivery must be evaluated. The primary objectives for this project are: (1) Establish that a fiber optic LIBS technique can be used to detect heavy metals to the required concentration levels; (2) Design and fabricate a fiber optic probe for integration with the penetrometer system for the analysis of heavy metals in soil samples; (3) Design, fabricate, and test an integrated fiber/penetrometer system; (4) Fabricate a rugged, field deployable laser source and detection hardware system; and (6) Demonstrate the prototype in field deployments.

  4. Vibration-displacement measurements with a highly stabilised optical fiber Michelson interferometer system

    Science.gov (United States)

    Xie, Fang; Ren, Junyu; Chen, Zhimin; Feng, Qibo

    2010-02-01

    A highly stabilised vibration-displacement measurement system, which employs fiber Bragg gratings (FBGs) to interleave two fiber Michelson interferometers that share the common-interferometric-optical path, is presented. The phase change in the interferometric signals of the two fiber Michelson interferometers have been tracked, respectively, with two electronic feedback loops. One of the fiber interferometers is used to stabilise the system by the use of an electronic feedback loop to compensate the environmental disturbances. The second fiber interferometer is used to perform the measurement task and employs another electronic feedback loop to track the phase change in the interferometric signal. The measurement system is able to measure vibration-displacement and provide the sense of direction of the displacement. The frequency range of the measured vibration-displacement is from 0.1 to 200 Hz and the measurement resolution is 10 nm.

  5. Design and analysis of a novel latch system implementing fiber-reinforced composite materials

    Science.gov (United States)

    Guevara Arreola, Francisco Javier

    The use of fiber-reinforced composite materials have increased in the last four decades in high technology applications due to their exceptional mechanical properties and low weight. In the automotive industry carbon fiber have become popular exclusively in luxury cars because of its high cost. However, Carbon-glass hybrid composites offer an effective alternative to designers to implement fiber-reinforced composites into several conventional applications without a considerable price increase maintaining most of their mechanical properties. A door latch system is a complex mechanism that is under high loading conditions during car accidents such as side impacts and rollovers. Therefore, the Department of Transportation in The United States developed a series of tests that every door latch system comply in order to be installed in a vehicle. The implementation of fiber-reinforced composite materials in a door latch system was studied by analyzing the material behavior during the FMVSS No. 206 transverse test using computational efforts and experimental testing. Firstly, a computational model of the current forkbolt and detent structure was developed. Several efforts were conducted in order to create an effective and time efficient model. Two simplified models were implemented with two different contact interaction approaches. 9 composite materials were studied in forkbolt and 5 in detent including woven carbon fiber, unidirectional carbon fiber, woven carbon-glass fiber hybrid composites and unidirectional carbon-glass fiber hybrid composites. The computational model results showed that woven fiber-reinforced composite materials were stiffer than the unidirectional fiber-reinforced composite materials. For instance, a forkbolt made of woven carbon fibers was 20% stiffer than a forkbolt made of unidirectional fibers symmetrically stacked in 0° and 90° alternating directions. Furthermore, Hybrid composite materials behaved as expected in forkbolt noticing a decline

  6. 10-channel fiber array fabrication technique for parallel optical coherence tomography system

    Science.gov (United States)

    Arauz, Lina J.; Luo, Yuan; Castillo, Jose E.; Kostuk, Raymond K.; Barton, Jennifer

    2007-02-01

    Optical Coherence Tomography (OCT) shows great promise for low intrusive biomedical imaging applications. A parallel OCT system is a novel technique that replaces mechanical transverse scanning with electronic scanning. This will reduce the time required to acquire image data. In this system an array of small diameter fibers is required to obtain an image in the transverse direction. Each fiber in the array is configured in an interferometer and is used to image one pixel in the transverse direction. In this paper we describe a technique to package 15μm diameter fibers on a siliconsilica substrate to be used in a 2mm endoscopic probe tip. Single mode fibers are etched to reduce the cladding diameter from 125μm to 15μm. Etched fibers are placed into a 4mm by 150μm trench in a silicon-silica substrate and secured with UV glue. Active alignment was used to simplify the lay out of the fibers and minimize unwanted horizontal displacement of the fibers. A 10-channel fiber array was built, tested and later incorporated into a parallel optical coherence system. This paper describes the packaging, testing, and operation of the array in a parallel OCT system.

  7. Theoretical model of optical fiber secure communication system with chaotic multiple-quantum-well lasers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chaotic synchronization of injected multiple-quantum-well lasers of optical fiber system and a theoretical model of optical fiber chaotic secure communication system are presented by coupling a chaotic multiple-quantum-well laser synchronization system and a fiber channel. A new chaotic encoding method of chaos phase shift keying On/Off is proposed for optical fiber secure communications. Chaotic synchronization is achieved numerically in long-haul fiber system at wavelength 1.55μm. The effect of the nonlinear-phase of fiber is analyzed on chaotic signal and synchronization. A sinusoidal signal of 0.2 GHz frequency is simulated numerically with chaos masking in long-haul fiber analog communication at wavelength 1.55μm while a digital signal of 0.5 Gbit/s bit rate is simulated numerically with c1 haos masking and a rate of 0.05 Gbit/s are also simulated numerically with chaos shift keying and chaos phase shift keying On/Off in long-haul fiber digital communications at wavelength 1.55μm

  8. Coherently-combined two channel femtosecond fiber CPA system producing 3 mJ pulse energy.

    Science.gov (United States)

    Klenke, Arno; Seise, Enrico; Demmler, Stefan; Rothhardt, Jan; Breitkopf, Sven; Limpert, Jens; Tünnermann, Andreas

    2011-11-21

    We present a fiber CPA system consisting of two coherently combined fiber amplifiers, which have been arranged in an actively stabilized Mach-Zehnder interferometer. Pulse durations as short as 470 fs and pulse energies of 3 mJ, corresponding to 5.4 GW of peak power, have been achieved at an average power of 30 W.

  9. Millimeter-wave and Terahertz Reconfigurable Radio-over-Fiber Systems

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José

    when deploying fiber is not an option. Radio-over-Fiber (RoF) technologies have evolved from a blue sky academic topic in the 90s to a main driver within the current quest for the 5th generation mobile systems (5G). A twist in RoF technologies is that it has found along the way niches in areas non...

  10. Analyzing Fourier Transforms for NASA DFRC's Fiber Optic Strain Sensing System

    Science.gov (United States)

    Fiechtner, Kaitlyn Leann

    2010-01-01

    This document provides a basic overview of the fiber optic technology used for sensing stress, strain, and temperature. Also, the document summarizes the research concerning speed and accuracy of the possible mathematical algorithms that can be used for NASA DFRC's Fiber Optic Strain Sensing (FOSS) system.

  11. Controllable Optical Solitons in Optical Fiber System with Distributed Coefficients

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-Fei; HE Wan-Quan; ZHANG Pei; ZHANG Peng

    2011-01-01

    We present how to control the dynamics of optical solitons in optical fibers under nonlinearity and dispersion management, together with the fiber loss or gain. We obtain a family of exact solutions for the nonlinear Schr(o)dinger equation, which describes the propagation of optical pulses in optical fibers, and investigate the dynamical features of solitons by analyzing the exact analytical solutions in different physical situations. The results show that under the appropriate condition, not only the group velocity dispersion and the nonlinearity, but also the loss/gain can be used to manipulate the light pulse.

  12. Modeling and simulation on temperature performance in fiber optic gyroscope fiber coil of shipborne strapdown inertial navigation system

    Science.gov (United States)

    Wang, Yueze; Ma, Lin; Yu, Hao; Gao, Hongyu; Yuan, Yujie

    2016-10-01

    Compared with the traditional gyros, Fiber optic gyroscope (FOG) based on sagnac effect has the significant features, such as, long life, low cost, wide dynamic range, etc. These features have developed new applications of the gyroscope not only in industrial application area but also in aerospace application area. Now, the FOG has played a very important role in shipborne Strapdown Inertial Navigation System (SINS). The fiber coil, as one of the most critical components in FOG, is extremely sensitive to changes in temperature. Here, by study the environment temperature in shipborne SINS, the temperature performance of the FOG was analyzed. Firstly, on the base of the research about the theory of Shupe non-reciprocal errors caused by temperature, the discrete mathematics formula of the temperature error in FOG of SINS was built .Then the element model of the fiber coil in SINS was built based on the discrete model of the fiber coil in temperature error in FOG. A turn-by-turn quantization temperature bias error model is establish. Finally, based on the temperature models mentioned above, the temperature performance of FOG in shipborne SINS was analyzed. With finite element analysis, numerical simulations were carried out to quantitatively analyze the angular error induced by temperature excitation in SINS. The model was validated by comparing numerical and experimental results.

  13. Towards mid-infrared fiber-optic devices and systems for sensing, mapping and imaging

    Science.gov (United States)

    Jayasuriya, D.; Wilson, B.; Furniss, D.; Tang, Z.; Barney, E.; Benson, T. M.; Seddon, A. B.

    2016-03-01

    Novel chalcogenide glass-based fiber opens up the mid-infrared (MIR) range for real-time monitoring and control in medical diagnostics and chemical processing. Fibers with long wavelength cut-off are of interest here. Sulfide, selenide and telluride based chalcogenide glass are candidates, but there are differences in their glass forming region, thermal stability and in the short and long wavelength cut-off positions. In general sulfide and selenide glasses have greater glass stability, but shorter long-wavelength cut-off edge, compared to telluride glasses; selenide-telluride glasses are a good compromise. Low optical loss selenide-telluride based long wavelength fibers could play a substantial role in improving medical diagnostic systems, chemical sensing, and processing, and in security and agriculture. For biological tissue, the molecular finger print lies between ~3-15 μm wavelengths in the MIR region. Using MIR spectral mapping, information about diseased tissue may be obtained with improved accuracy and in vivo using bright broadband MIR super-continuum generation (SCG) fiber sources and low optical loss fiber for routing. The Ge-As-Se-Te chalcogenide glass system is a potential candidate for both MIR SCG and passive-routing fiber, with good thermal stability, wide intrinsic transparency from ~1.5 to 20 μm and low phonon energy. This paper investigates Ge-As-Se-Te glass system pairs for developing high numerical aperture (NA) small-core, step-index optical fiber for MIR SCG and low NA passive step-index optical fiber for an in vivo fiber probe. Control of fiber geometry of small-core optical fiber and methods of producing the glass material are also included in this paper.

  14. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

    Science.gov (United States)

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-11-16

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  15. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Baiwang Zhao

    2015-11-01

    Full Text Available In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18–22 g/m3 to a range of 13.5–18.3 g/m3. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  16. Fiber Optic Sensor System for Cryogenic Fuel Measurement Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I project will address the feasibility of using a fiber Bragg grating array as a means of detecting liquid and slush hydrogen in gravity and zero...

  17. Application of optical fiber sensing technology in the hydraulic decoking monitoring system

    Science.gov (United States)

    Fan, Yun-feng; Tong, Xing-lin; Ji, Tao; Gao, Xue-qing; Zhong, Dong

    2013-09-01

    On the basis of the analysis of the current hydraulic decoking monitoring system, it is proposed that use optical fiber Bragg grating (FBG) vibration sensor and fiber Fabry-Perot (FP) acoustic sensors to online monitor vibration signal and audio signal hydraulic of the coke drum in the running state progress, analysis the vibration sensor and acoustic sensor used in the system. Based on the actual monitoring results in Sinopec Wuhan Branch , the fiber optic acoustic emission sensors is more suitable for the hydraulic decoking online monitoring system than the FBG vibration sensor ,which can more accurate monitor of hydraulic decoking.

  18. Structurally distinct nicotine immunogens elicit antibodies with non-overlapping specificities

    Science.gov (United States)

    Pravetoni, M; Keyler, DE; Pidaparthi, RR; Carroll, FI; Runyon, SP; Murtaugh, MP; Earley, CA; Pentel, PR

    2011-01-01

    Nicotine conjugate vaccine efficacy is limited by the concentration of nicotine-specific antibodies that can be reliably generated in serum. Previous studies suggest that the concurrent use of 2 structurally distinct nicotine immunogens in rats can generate additive antibody responses by stimulating distinct B cell populations. In the current study we investigated whether it is possible to identify a third immunologically distinct nicotine immunogen. The new 1′-SNic immunogen (2S)-N,N′-(disulfanediyldiethane-2,1-diyl)bis[4-(2-pyridin-3-ylpyrrolidin-1-yl)butanamide] conjugated to keyhole limpet hemocyanin (KLH) differed from the existing immunogens 3′-AmNic-rEPA and 6-CMUNic-BSA in linker position, linker composition, conjugation chemistry, and carrier protein. Vaccination of rats with 1′-SNic-KLH elicited high concentrations of high affinity nicotine-specific antibodies. The antibodies produced in response to 1′-SNic-KLH did not appreciably cross-react in ELISA with either 3′-AmNic-rEPA or 6-CMUNic-BSA or vice-versa, showing that the B cell populations activated by each of these nicotine immunogens were non-overlapping and distinct. Nicotine retention in serum was increased and nicotine distribution to brain substantially reduced in rats vaccinated with 1′-SNic-KLH compared to controls. Effects of 1′-SNic-KLH on nicotine distribution were comparable to those of 3′-AmNic-rEPA which has progressed to late stage clinical trials as an adjunct to smoking cessation. These data show that it is possible to design multiple immunogens from a small molecule such as nicotine which elicit independent immune responses. This approach could be applicable to other addiction vaccines or small molecule targets as well. PMID:22100986

  19. Calibration and deployment of a fiber-optic sensing system for monitoring debris flows.

    Science.gov (United States)

    Huang, Ching-Jer; Chu, Chung-Ray; Tien, Tsung-Mo; Yin, Hsiao-Yuen; Chen, Ping-Sen

    2012-01-01

    This work presents a novel fiber-optic sensing system, capable of monitoring debris flows or other natural hazards that produce ground vibrations. The proposed sensing system comprises a demodulator (BraggSCOPE, FS5500), which includes a broadband light source and a data logger, a four-port coupler and four Fiber Bragg Grating (FBG) accelerometers. Based on field tests, the performance of the proposed fiber-optic sensing system is compared with that of a conventional sensing system that includes a geophone or a microphone. Following confirmation of the reliability of the proposed sensing system, the fiber-optic sensing systems are deployed along the Ai-Yu-Zi and Chu-Shui Creeks in Nautou County of central Taiwan for monitoring debris flows. Sensitivity test of the deployed fiber-optic sensing system along the creek banks is also performed. Analysis results of the seismic data recorded by the systems reveal in detail the frequency characteristics of the artificially generated ground vibrations. Results of this study demonstrate that the proposed fiber-optic sensing system is highly promising for use in monitoring natural disasters that generate ground vibrations.

  20. Low-latency fiber-millimeter-wave system for future mobile fronthauling

    Science.gov (United States)

    Tien Dat, Pham; Kanno, Atsushi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

    2016-02-01

    A seamless combination of fiber and millimeter-wave (MMW) systems can be very attractive for future heterogeneous mobile networks such as 5G because of its flexibility and high bandwidth. Analog mobile signal transmission over seamless fiber-MMW systems is very promising to reduce the latency and the required band-width, and to simplify the systems. However, stable and high-performance seamless systems are indispensable to conserve the quality of the analog signal transmission. In this paper, we present several technologies to develop such seamless fiber-MMW systems. In the downlink direction, a high-performance system can be realized using a high-quality optical MMW signal generator and a self-homodyne MMW signal detector. In the uplink direction, a cascade of radio-on-radio and radio-over-fiber systems using a burst-mode optical amplifier can support bursty radio signal transmission. A full-duplex transmission with negligible interference effects can be realized using frequency multiplexing in the radio link and wavelength-division multiplexing in the optical link. A high-spectral efficiency MMW-over-fiber system using an intermediate frequency-over-fiber system and a high-quality remote delivery of a local oscillator signal is highly desirable to reduce the costs.

  1. Design and Realization of Phased Array Radar Optical Fiber Transmission System

    Institute of Scientific and Technical Information of China (English)

    HU Shan-qing; LIU Feng; LONG Teng

    2007-01-01

    One optical fiber transmission system is designed.The modularization optical fiber transmission adapters were utilized in the system,so the system structure could be flexibly scalable.The sub-array adapter and signal processor adapter were designed and realized utilizing the new field programmable gate array (FPGA) which could drive the optical transceiver.The transmission agreement was designed based on the data stream.In order to solve the signal synchronization problem of the optical fiber transmitted phased array radar,a method named synchronous clock was designed.The fiber transmission error code rate of the system was zero with an experimental transmission velocity of 800 Mbit/s.The phased array radar system has detected the airplane target,thus validated the feasibility of the design method.

  2. Multi-fibers connectors systems for FOCCoS-PFS-Subaru

    CERN Document Server

    de Oliveira, Antonio Cesar; Marrara, Lucas Souza; Santos, Leandro Henrique dos; de Arruda, Marcio Vital; Santos, Jesulino Bispo dos; Ferreira, Décio; Rosa, Josimar Aparecido; Vilaca, Rodrigo de Paiva; de Oliveira, Laerte Sodre Junior Claudia Mendes; Gunn, James E

    2014-01-01

    The Fiber Optical Cable and Connector System (FOCCoS), provides optical connection between 2400 positioners and a set of spectrographs through optical fibers cables as part of PFS instrument for Subaru telescope. The optical fiber cable will be segmented in 3 parts along the route, cable A, cable B and cable C, connected by a set of multi-fiber connectors. The company USCONEC produces the multi-fiber connector under study. The USCONEC 32F model can connect 32 optical fibers in a 4 x 8 matrix arrangement. The ferrules are made of a durable composite, Polyphenylene Sulfide (PPS) based thermoplastic. The connections are held in place by a push-on/pull-off latch, and the connector can also be distinguished by a pair of metal guide pins that protrude from the front of the connector. Two fibers per connector will be used for monitoring the connection procedure. It was found to be easy to polish and it is small enough to be mounted in groups. Highly multiplexed instruments like PFS require a fiber connector system t...

  3. Use of fiber optic-based distributed temperature measurement system for electrical machines

    Science.gov (United States)

    Rajendran, Veera P.; Deblock, Mark; Wetzel, Todd; Lusted, Mark; Kaminski, Christopher; Childers, Brooks A.

    2003-11-01

    A fiber optic based distributed temperature measurement system was implemented in stator windings (straight copper bars) as well as in the end-windings (curved copper bars) of a motor. Usually, in electrical machines such as motors or generators, only a few conventional temperature sensors are used, whereas the distributed temperature system has the potential of providing very detailed temperature distribution by having hundreds of sensors in a single fiber. The sensors were made of Bragg gratings etched onto the fiber itself. For the present study, the spatial resolution of the sensors is 6 mm (nominally at 1/4" apart). The technique uses Optical Frequency Domain Reflectometry (OFDR) to process the back-reflected light signal indicative of the thermal filed. A prototype fiber optic system was implemented in a motor made by GE industrial systems. The sensing length (length of the stator) for the motor was 0.75 m containing approximately 150 sensors thus providing very detailed temperature data. Performance tests were conducted at different heat loads representing different electrical conditions. Continuous tests for the duration of 19 hours were conducted. The temperature of stator windings varied from ambient (~ 23°C) to approximately 85°C. As reference, Resistance Temperature Devices (RTDs) were installed in adjacent slots to the slot where fiber optic sensors were installed. A total of 8 sensors were installed but data were collected on only 3 fibers. Fiber sensor measurements were found to track the temperature trends very well. The fiber data agreed with RTD data within +/- 3°C in the entire duration. The RMS value of difference between the fiber and RTD on one side was 0.3°C, and with the RTD on the other side was 0.5°C. The fiber measurements also showed how hotspots could be missed by using few RTDs, as is done in the industry. The fiber measurements also showed the temperature distribution in the endwindings, an area not normally monitored. The

  4. Comparison of Patient Outcomes in 3725 Overlapping vs 3633 Nonoverlapping Neurosurgical Procedures Using a Single Institution's Clinical and Administrative Database.

    Science.gov (United States)

    Zygourakis, Corinna C; Keefe, Malla; Lee, Janelle; Barba, Julio; McDermott, Michael W; Mummaneni, Praveen V; Lawton, Michael T

    2017-02-01

    Overlapping surgery is a common practice to improve surgical efficiency, but there are limited data on its safety. To analyze the patient outcomes of overlapping vs nonoverlapping surgeries performed by multiple neurosurgeons. Retrospective review of 7358 neurosurgical procedures, 2012 to 2015, at an urban academic hospital. Collected variables: patient age, gender, insurance, American Society of Anesthesiologists score, severity of illness, mortality risk, admission type, transfer source, procedure type, surgery date, number of cosurgeons, presence of neurosurgery resident/fellow/another attending, and overlapping vs nonoverlapping surgery. Outcomes: procedure time, length of stay, estimated blood loss, discharge location, 30-day mortality, 30-day readmission, return to operating room, acute respiratory failure, and severe sepsis. Statistics: univariate, then multivariate mixed-effect models. Overlapping surgery patients (n = 3725) were younger and had lower American Society of Anesthesiologists scores, severity of illness, and mortality risk (P < .0001) than nonoverlapping surgery patients (n = 3633). Overlapping surgeries had longer procedure times (214 vs 172 min; P < .0001), but shorter length of stay (7.3 vs 7.9 d; P = .010) and lower estimated blood loss (312 vs 363 mL’s; P = .003). Overlapping surgery patients were more likely to be discharged home (73.6% vs 66.2%; P < .0001), and had lower mortality rates (1.3% vs 2.5%; P = .0005) and acute respiratory failure (1.8% vs 2.6%; P = .021). In multivariate models, there was no significant difference between overlapping and nonoverlapping surgeries for any patient outcomes, except for procedure duration, which was longer in overlapping surgery (estimate = 23.03; P < .001). When planned appropriately, overlapping surgery can be performed safely within the infrastructure at our academic institution.

  5. Gate current modeling and optimal design of nanoscale non-overlapped gate to source/drain MOSFET

    Institute of Scientific and Technical Information of China (English)

    Ashwani K.Rana; Narottam Chand; Vinod Kapoor

    2011-01-01

    A novel nanoscale MOSFET with a source/drain-to-gate non-overlapped and high-k spacer structure has been demonstrated to reduce the gate leakage current for the first time.The gate leakage behaviour of the novel MOSFET structure has been investigated with the help of a compact analytical model and Sentaurus simulation.A fringing gate electric field through the dielectric spacer induces an inversion layer in the non-overlap region to act as an extended S/D (source/drain) region.It is found that an optimal source/drain-to-gate non-overlapped and high-k spacer structure has reduced the gate leakage current to a great extent as compared to those of an overlapped structure.Further,the proposed structure had improved off current,subthreshold slope and drain induced barrier lowering (DIBL) characteristics.It is concluded that this structure solves the problem of high leakage current without introducing extra series resistance.

  6. Final Scientific and Technical Report - Practical Fiber Delivered Laser Ignition Systems for Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Yalin, Azer [Seaforth, LLC

    2014-03-30

    Research has characterized advanced kagome fiber optics for their use in laser ignition systems. In comparison to past fibers used in laser ignition, these fibers have the important advantage of being relatively bend-insensitivity, so that they can be bent and coiled without degradation of output energy or beam quality. The results are very promising for practical systems. For pulse durations of ~12 ns, the fibers could deliver >~10 mJ pulses before damage onset. A study of pulse duration showed that by using longer pulse duration (~20 – 30 ns), it is possible to carry even higher pulse energy (by factor of ~2-3) which also provides future opportunities to implement longer duration sources. Beam quality measurements showed nearly single-mode output from the kagome fibers (i.e. M2 close to 1) which is the optimum possible value and, combined with their high pulse energy, shows the suitability of the fibers for laser ignition. Research has also demonstrated laser ignition of an engine including reliable (100%) ignition of a single-cylinder gasoline engine using the laser ignition system with bent and coiled kagome fiber. The COV of IMEP was <2% which is favorable for stable engine operation. These research results, along with the continued reduction in cost of laser sources, support our commercial development of practical laser ignition systems.

  7. Comparison between reflectance spectra obtained with an integrating sphere and a fiber optic collection system

    Science.gov (United States)

    Norvang Nilsen, Lill T.; Fiskerstrand, Elisanne J.; Koenig, Karsten; Bakken, B.; Grini, D.; Standahl, O.; Milner, Thomas E.; Berns, Michael W.; Nelson, J. Stuart; Svaasand, Lars O.

    1996-01-01

    Visible reflectance spectra of human skin might serve as a valuable tool for determining blood volume and pigmentation. They can therefore be used to evaluate the response to various skin treatments such as, e.g., port-wine stain therapy. A fiber-optic system is preferable for clinical evaluation of the therapeutic response due to its higher flexibility. Diffuse reflectance spectra obtained using a fiber system are compared with the corresponding spectra from an integrating sphere system. The results show that the most accurate reflectance spectra are obtained using the integrating sphere set-up. The aperture should then be much larger than the optical penetration depth of the skin. The system will then collect all the reflected light from superficial and deeper layers, and this enables a qualitative comparison between the wavelengths. However, the size and localization of many dermal lesions limit its use. In these cases the fiber-optic system is preferable. Light with an optical penetration depth shorter than the distance between the excitation and collecting fibers is, however, favorized. Normal dermis has typically a penetration depth of 600 micrometers and 2000 micrometers for, respectively, green/yellow and red light. Consequently, the collection efficiency of a typical fiber-optic system with a distance of 100 - 200 micrometers between the emitting and collecting fibers, will be higher in the green/yellow than in the red part of the spectrum. It is, however, important to remember that the relevant parameter is the change in reflectance at each particular wavelength, rather than comparison between the wavelengths. When such a comparison is required, the spectra collected by the fiber-optic system can be calibrated. The more accurate integrating sphere system is maybe preferable in a research laboratory environment, whereas the more flexible fiber-optic system is the most applicable for use in the clinic.

  8. As assessment of power system vulnerability to release of carbon fibers during commercial aviation accidents

    Science.gov (United States)

    Larocque, G. R.

    1980-01-01

    The vulnerability of a power distribution system in Bedford and Lexington, Massachusetts to power outages as a result of exposure to carbon fibers released in a commercial aviation accident in 1993 was examined. Possible crash scenarios at Logan Airport based on current operational data and estimated carbon fiber usage levels were used to predict exposure levels and occurrence probabilities. The analysis predicts a mean time between carbon fiber induced power outages of 2300 years with an expected annual consequence of 0.7 persons losing power. In comparison to historical outage data for the system, this represents a 0.007% increase in outage rate and 0.07% increase in consequence.

  9. A FEMTOSECOND-LEVEL FIBER-OPTICS TIMING DISTRIBUTION SYSTEM USING FREQUENCY-OFFSET INTERFEROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Staples, J.W.; Byrd, J.; Doolittle, L.; Huang, G.; Wilcox, R.

    2009-10-17

    An optical fiber-based frequency and timing distribution system based on the principle of heterodyne interferometry has been in development at LBNL for several years. The fiber drift corrector has evolved from an RF-based to an optical-based system, from mechanical correctors (piezo and optical trombone) to fully electronic, and the electronics from analog to fully digital, all using inexpensive off-the-shelf commodity fiber components. Short-term optical phase jitter and long-term phase drift are both in the femtosecond range over distribution paths of 2 km or more.

  10. Cost-effective add-drop fiber optic microcell system for CDMA cellular network evolution

    Science.gov (United States)

    Cheong, Jong M.; Ham, David; Song, Myoung H.; Son, Yong S.

    2001-10-01

    In this paper, we propose a cost effective add-drop fiber-optic microcell system for CDMA cellular network. The add-drop microcell is compatible with the existing PCS or digital cellular services (DCS) systems & networks. The proposed fiber-optic add-drop access network is independent of the different channels and gives flexibility in evolution scenarios. This add-drop network provides the optimum solution to cut-down the additional rental fees by sharing the existing fiber-optic cable for cellular/PCS service providers who want to provide third generation services.

  11. Calibration and deployment of a fiber-optic sensing system for monitoring debris flows

    National Research Council Canada - National Science Library

    Huang, Ching-Jer; Chu, Chung-Ray; Tien, Tsung-Mo; Yin, Hsiao-Yuen; Chen, Ping-Sen

    2012-01-01

    .... The proposed sensing system comprises a demodulator (BraggSCOPE, FS5500), which includes a broadband light source and a data logger, a four-port coupler and four Fiber Bragg Grating (FBG) accelerometers...

  12. Photon Counting System for High-Sensitivity Detection of Bioluminescence at Optical Fiber End.

    Science.gov (United States)

    Iinuma, Masataka; Kadoya, Yutaka; Kuroda, Akio

    2016-01-01

    The technique of photon counting is widely used for various fields and also applicable to a high-sensitivity detection of luminescence. Thanks to recent development of single photon detectors with avalanche photodiodes (APDs), the photon counting system with an optical fiber has become powerful for a detection of bioluminescence at an optical fiber end, because it allows us to fully use the merits of compactness, simple operation, highly quantum efficiency of the APD detectors. This optical fiber-based system also has a possibility of improving the sensitivity to a local detection of Adenosine triphosphate (ATP) by high-sensitivity detection of the bioluminescence. In this chapter, we are introducing a basic concept of the optical fiber-based system and explaining how to construct and use this system.

  13. NASA Armstrong Flight Research Center (AFRC) Fiber Optic Sensing System (FOSS) Technology

    Science.gov (United States)

    Richards, Lance; Parker, Allen R.; Piazza, Anthony; Chan, Patrick; Hamory, Phil; Pena, Frank

    2014-01-01

    Attached is a power point presentation created to assist the Tech Transfer Office and the FOSS project team members in responding to inquiries from the public about the capabilities of the Fiber Optic Sensing System.

  14. Advanced Modular, Multi-Channel, High Speed Fiber Optic Sensing System for Acoustic Emissions Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Fiber Optic Systems Corporation (IFOS) proposes to prove the feasibility of innovations based on ultra-light-weight, ultra-high-speed, multi-channel,...

  15. Next Generation Fiber Coherent Lidar System for Wake Vortex Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SibellOptics proposes to develop an eye-safe, long-range, compact, versatile, all-fiber wind LIDAR system for wake vortex measurement and other wind measurement...

  16. Self-Monitoring Strengthening System Based on Carbon Fiber Laminate

    Directory of Open Access Journals (Sweden)

    Rafal Krzywon

    2016-01-01

    Full Text Available Externally bonded composites reinforced with high-strength fibers are increasingly popular in construction, especially in structures’ strengthening, where the best possible mechanical properties are required. At the same time the ability to autodetect threats is one of the most desirable features of contemporary structures. The authors of the paper have developed an intelligent fabric, wherein the carbon fibers play the role of not only tensile reinforcement but also strain sensor. The idea is based on the construction of the strain gauge, where the thread of carbon fibers arranged in zig-zag pattern works as electrical conductor and is insulated by parallel thread of glass or acrylic fibers. Preliminary laboratory tests were designed to create effective measurement techniques and assess the effectiveness of the strengthening of selected building structures, as reinforced concrete and timber beams. Presented in the paper, selected results of these studies are very promising, although there were some noted problems to be considered in next steps. The main problem here is the control of the cross section of the fibers tow, affecting the total resistance of the fabric. One of the main deficiencies of the proposed solution is also sensitivity to moisture.

  17. Compact Wireless Access Nodes for WDM Bidirectional Radio-over-Fiber System Based on RSOA

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact.......We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact....

  18. The effect of ceramic fibers on the immune system.

    Science.gov (United States)

    Tulinská, Jana; Kuricová, Miroslava; Lisková, Aurelia; Kováciková, Zuzana; Tatrai, Elizabeth

    2005-12-01

    Male Sprague-Dawley rats were treated by intratracheal instillation with 1 mg/animal of refractory ceramic fibers. Intratracheal exposure to ceramic fibers led to significant changes of immune response. Results of proliferative activity of spleen lymphocytes showed significantly decreased proliferative activity of T-cells in response to mitogens phytohemagglutinin and concanavalin A in animals given ceramic fibers in comparison with control rats. Similarly, T-dependent B-cell response to pokeweed mitogen was significantly suppressed. Spontaneous proliferative activity of lymphocytes in non-stimulated spleen cell cultures did not differ in exposed and control rats. No significant changes were found among groups in percentage of phagocytic blood polymorphonuclear leukocytes and percentage of cells with respiratory burst.

  19. Industrial fiber beam delivery system for ultrafast lasers: applications and recent advances

    Science.gov (United States)

    Eilzer, Sebastian; Funck, Max C.; Wedel, Björn

    2016-03-01

    Fiber based laser beam delivery is the method of choice for high power laser applications whenever great flexibility is required. For cw-lasers fiber beam delivery has long been established but has recently also become available for ultrafast lasers. Using micro-structured hollow core fibers that guide the laser beam mostly inside a hollow core, nonlinear effects and catastrophic damage that arise in conventional glass fibers can be avoided. Today, ultrafast pulses with several 100 μJ and hundreds of MW can be transmitted in quasi single mode fashion. In addition, the technology opens new possibilities for beam delivery systems as the pulse propagation inside the fiber can be altered on purpose. For example to shorten the pulse duration of picosecond lasers down into the femtosecond regime. We present a modular fiber beam delivery system for micromachining applications with industrial pico- and femtosecond lasers that is flexibly integrated into existing applications. Micro-structured hollow core fibers inside the sealed laser light cable efficiently guide high-power laser pulses over distances of several meters with excellent beam quality, while power, pulse duration and polarization are maintained. Robust and stable beam transport during dynamic operation as in robot or gantry systems will be discussed together with optional pulse compression.

  20. Retinal nerve fiber layer thickness and neuropsychiatric manifestations in systemic lupus erythematosus.

    Science.gov (United States)

    Shulman, S; Shorer, R; Wollman, J; Dotan, G; Paran, D

    2017-01-01

    Background Cognitive impairment is frequent in systemic lupus erythematosus. Atrophy of the corpus callosum and hippocampus have been reported in patients with systemic lupus erythematosus, and diffusion tensor imaging studies have shown impaired white matter integrity, suggesting that white matter damage in systemic lupus erythematosus may underlie the cognitive impairment as well as other neuropsychiatric systemic lupus erythematosus manifestations. Retinal nerve fiber layer thickness, as assessed by optical coherence tomography, has been suggested as a biomarker for white matter damage in neurologic disorders such as multiple sclerosis, Alzheimer's disease and Parkinson's disease. Retinal nerve fiber layer thinning may occur early, even in patients with mild clinical symptoms. Aim The objective of this study was to assess the association of retinal nerve fiber layer thickness, as a biomarker of white matter damage in systemic lupus erythematosus patients, with neuropsychiatric systemic lupus erythematosus manifestations, including cognitive impairment. Methods Twenty-one consecutive patients with systemic lupus erythematosus underwent neuropsychological testing using a validated computerized battery of tests as well as the Rey-Auditory verbal learning test. All 21 patients, as well as 11 healthy, age matched controls, underwent optical coherence tomography testing to assess retinal nerve fiber layer thickness. Correlations between retinal nerve fiber layer thickness and results in eight cognitive domains assessed by the computerized battery of tests as well as the Rey-Auditory verbal learning test were assessed in patients with systemic lupus erythematosus, with and without neuropsychiatric systemic lupus erythematosus, and compared to retinal nerve fiber layer thickness in healthy controls. Results No statistically significant correlation was found between retinal nerve fiber layer thickness in patients with systemic lupus erythematosus as compared to healthy

  1. Mechanical and optical characteristics of a new fiber optical system used for cardiac contraction measurement.

    Science.gov (United States)

    Kloppe, A; Hoeland, K; Müller, S; Hexamer, M; Nowack, G; Mügge, A; Werner, J

    2004-10-01

    In order to obtain a better physiological performance and a closer restoration of the regular rhythm of failing hearts, a new fiber optical sensor system for the measurement of cardiac contraction has been developed. It consists of an opto-electrical unit and a sensing fiber which has to be positioned in the heart. The objective of this new fiber optic sensor system is to use the inotropic information to adjust a stimulation algorithm in single or multichamber pacing or to detect arrhythmia in insufficient heart function. In this study, the mechanical and optical characteristics of different fibers are investigated. The relationship between the attenuation (with an achieved numerical maximum of 0.3 dB), the bending diameter and the angle of bending is determined in a range of 20-160 mm. The most suitable fiber for the application in cardiological problems is determined (WT8 fiber), for which the sensitivity is analyzed. Additionally, power spectra are calculated from WT8 fiber signals obtained from pig hearts, working under physiological conditions. The maximal frequency response was 23 Hz. It is concluded that the fiber optical measurement of cardiac contraction is not only feasible and reproducible, but the WT8 fiber also shows optimal behavior in the range of parameters occurring in the heart chambers. Nevertheless, in order to restrict the measured signal reliably to bending processes within the chambers only, it is concluded that a special combined fiber has to be constructed with a high sensitivity only at its terminal section within the heart.

  2. Using single photons to improve fiber optic communication systems

    Science.gov (United States)

    Pinto, Armando N.; Silva, Nuno A.; Almeida, Álvaro J.; Muga, Nelson J.

    2014-08-01

    We show how to generate, encode, transmit and detect single photons. By using single photons we can address two of the more challenging problems that communication engineers face nowadays: capacity and security. Indeed, by decreasing the number of photons used to encode each bit, we can efficiently explore the full capacity to carry information of optical fibers, and we can guarantee privacy at the physical layer. We present results for single and entangled photon generation. We encode information in the photons polarization and after transmission we retrieve that information. We discuss the impact of fiber birefringence on the photons polarization.

  3. Ground strain measuring system using optical fiber sensors

    Science.gov (United States)

    Sato, Tadanobu; Honda, Riki; Shibata, Shunjiro; Takegawa, Naoki

    2001-08-01

    This paper presents a device to measure the dynamic horizontal shear strain of the ground during earthquake. The proposed device consists of a bronze plate with fiber Bragg grating sensors attached on it. The device is vertically installed in the ground, and horizontal shear strain of the ground is measured as deflection angle of the plate. Employment of optical fiber sensors makes the proposed device simple in mechanism and highly durable, which makes it easy to install our device in the ground. We conducted shaking table tests using ground model to verify applicability of the proposed device.

  4. Comparative efficiency analysis of fiber-array and conventional beam director systems in volume turbulence.

    Science.gov (United States)

    Vorontsov, Mikhail; Filimonov, Grigory; Ovchinnikov, Vladimir; Polnau, Ernst; Lachinova, Svetlana; Weyrauch, Thomas; Mangano, Joseph

    2016-05-20

    The performance of two prominent laser beam projection system types is analyzed through wave-optics numerical simulations for various atmospheric turbulence conditions, propagation distances, and adaptive optics (AO) mitigation techniques. Comparisons are made between different configurations of both a conventional beam director (BD) using a monolithic-optics-based Cassegrain telescope and a fiber-array BD that uses an array of densely packed fiber collimators. The BD systems considered have equal input power and aperture diameters. The projected laser beam power inside the Airy size disk at the target plane is used as the performance metric. For the fiber-array system, both incoherent and coherent beam combining regimes are considered. We also present preliminary results of side-by-side atmospheric beam projection experiments over a 7-km propagation path using both the AO-enhanced beam projection system with a Cassegrain telescope and the coherent fiber-array BD composed of 21 densely packed fiber collimators. Both wave-optics numerical simulation and experimental results demonstrate that, for similar system architectures and turbulence conditions, coherent fiber-array systems are more efficient in mitigation of atmospheric turbulence effects and generation of a hit spot of the smallest possible size on a remotely located target.

  5. Electrospun fibers of layered double hydroxide/biopolymer nanocomposites as effective drug delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Yue-E.; Zhu Hong; Chen Dan; Wang Ruiyu [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China); Tjiu, Weng Weei [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Liu Tianxi, E-mail: txliu@fudan.edu.cn [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China)

    2012-06-15

    Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on a combination of LDH-IBU with two kinds of biopolymers (i.e. PCL and PLA), to act as effective drug delivery systems. Ibuprofen (IBU) is chosen as a model drug, which is intercalated in MgAl-LDH by coprecipitation. Poly(oxyethylene-b-oxypropylene-b-oxyethylene) (Pluronic) is also added into PLA-based fibers as hydrophilicity enhancer and release modulator. LDH-IBU nanoparticles are uniformly dispersed throughout the nanocomposite fibers, as evidenced by transmission electron microscopy (TEM) observations. In vitro drug release studies show that initial IBU liberation from LDH-IBU/PCL composite fibers is remarkably slower than that from IBU/PCL fibers due to the sustained release property of LDH-IBU and heterogeneous nucleation effect of LDH-IBU on PCL chain segments. Surprisingly, the initial IBU release from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers is faster than that from the corresponding IBU/PLA and IBU/PLA/Pluronic fibers. This effect can be attributed to the strong interaction between alkyl groups in IBU molecules and methyl substituent groups of PLA as well as the hydrophilicity of LDH-IBU, which lead to an easier diffusion of water with a faster release of IBU from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers. - Graphical abstract: Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on the combination of LDHs with two kinds of biopolymers (i.e. PCL and PLA). LDH-IBU nanoparticles are uniformly dispersed throughout all the electrospun nanocomposite fibers even at a high loading level of 5 wt%. By combining the tunable drug release property of LDHs and electrospinning technique, the new drug delivery system is anticipated for effective loading and sustained release of drugs

  6. Measuring System for Interference Optical Fiber Acoustic Emission①

    Institute of Scientific and Technical Information of China (English)

    LUQizhu; ZHENGShengxuan

    1997-01-01

    A type of interference optical fiber acoustic emission sensor is described.With 10-10 m level resolution,megahertz-level frequency and response time less than 1 μs,this sensor possesses prominent measuring stability and can be used in state supervision and trouble diagnosis.

  7. Fiber Optic Based Thermometry System for Superconducting RF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Kochergin, Vladimir [Microxact Inc.

    2013-05-06

    Thermometry is recognized as the best technique to identify and characterize losses in SRF cavities. The most widely used and reliable apparatus for temperature mapping at cryogenic temperatures is based on carbon resistors (RTDs). The use of this technology on multi-cell cavities is inconvenient due to the very large number of sensors required to obtain sufficient spatial resolution. Recent developments make feasible the use of multiplexible fiber optic sensors for highly distributed temperature measurements. However, sensitivity of multiplexible cryogenic temperature sensors was found extending only to 12K at best and thus was not sufficient for SRF cavity thermometry. During the course of the project the team of MicroXact, JLab and Virginia Tech developed and demonstrated the multiplexible fiber optic sensor with adequate response below 20K. The demonstrated temperature resolution is by at least a factor of 60 better than that of the best multiplexible fiber optic temperature sensors reported to date. The clear path toward at least 10times better temperature resolution is shown. The first to date temperature distribution measurements with ~2.5mm spatial resolution was done with fiber optic sensors at 2K to4K temperatures. The repeatability and accuracy of the sensors were verified only at 183K, but at this temperature both parameters significantly exceeded the state of the art. The results of this work are expected to find a wide range of applications, since the results are enabling the whole new testing capabilities, not accessible before.

  8. A full-duplex CATV/wireless-over-fiber lightwave transmission system.

    Science.gov (United States)

    Li, Chung-Yi; Lu, Hai-Han; Ying, Cheng-Ling; Cheng, Chun-Jen; Lin, Che-Yu; Wan, Zhi-Wei; Chen, Jian-Hua

    2015-04-06

    A full-duplex CATV/wireless-over-fiber lightwave transmission system consisting of one broadband light source (BLS), two optical interleavers (ILs), one intensity modulator, and one phase modulator is proposed and experimentally demonstrated. The downstream light is optically promoted from 10Gbps/25GHz microwave (MW) data signal to 10Gbps/100GHz and 10Gbps/50GHz millimeter-wave (MMW) data signals in fiber-wireless convergence, and intensity-modulated with 50-550 MHz CATV signal. For up-link transmission, the downstream light is phase-remodulated with 10Gbps/25GHz MW data signal in fiber-wireless convergence. Over a 40-km single-mode fiber (SMF) and a 10-m radio frequency (RF) wireless transport, bit error rate (BER), carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple-beat (CTB) are observed to perform well in such full-duplex CATV/wireless-over-fiber lightwave transmission systems. This full-duplex 100-GHz/50-GHz/25-GHz/550-MHz lightwave transmission system is an attractive alternative. This transmission system not only presents its advancement in the integration of fiber backbone and CATV/wireless feeder networks, but also it provides the advantages of a communication channel for higher data rates and bandwidth.

  9. Design and characterization of a novel power over fiber system integrating a high power diode laser

    Science.gov (United States)

    Perales, Mico; Yang, Mei-huan; Wu, Cheng-liang; Hsu, Chin-wei; Chao, Wei-sheng; Chen, Kun-hsein; Zahuranec, Terry

    2017-02-01

    High power 9xx nm diode lasers along with MH GoPower's (MHGP's) flexible line of Photovoltaic Power Converters (PPCs) are spurring high power applications for power over fiber (PoF), including applications for powering remote sensors and sensors monitoring high voltage equipment, powering high voltage IGBT gate drivers, converters used in RF over Fiber (RFoF) systems, and system power applications, including powering UAVs. In PoF, laser power is transmitted over fiber, and is converted to electricity by photovoltaic cells (packaged into Photovoltaic Power Converters, or PPCs) which efficiently convert the laser light. In this research, we design a high power multi-channel PoF system, incorporating a high power 976 nm diode laser, a cabling system with fiber break detection, and a multichannel PPC-module. We then characterizes system features such as its response time to system commands, the PPC module's electrical output stability, the PPC-module's thermal response, the fiber break detection system response, and the diode laser optical output stability. The high power PoF system and this research will serve as a scalable model for those interested in researching, developing, or deploying a high power, voltage isolated, and optically driven power source for high reliability utility, communications, defense, and scientific applications.

  10. Design of a Very Small Residual Dispersion Fiber System for DWDM Operation Over the Entire C -&L-Bands of EDFA

    Institute of Scientific and Technical Information of China (English)

    Ravi; K.; Varshney; I.C.; Goyal; A.K.; Ghatak; Siny; Antony; C.

    2003-01-01

    We have given design of a very small residual dispersion fiber system consisting of a small dispersion fiber (SDF) with flat modal field and a corresponding dual core coaxial dispersion compensating fiber (DCF).

  11. Design and characterization of a real time particle radiography system based on scintillating optical fibers

    Science.gov (United States)

    Longhitano, F.; Lo Presti, D.; Bonanno, D. L.; Bongiovanni, D. G.; Leonora, E.; Randazzo, N.; Reito, S.; Sipala, V.; Gallo, G.

    2017-02-01

    The fabrication and characterization of a charged particle imaging system composed of a tracker and a residual range detector (RRD) is described. The tracker is composed of four layers of scintillating fibers (SciFi), 500 μm side square section, arranged to form two planes orthogonal to each other. The fibers are coupled to two Multi-Pixel Photon Counter (MPPC) arrays by means of a channel reduction system patented by the Istituto Nazionale di Fisica Nucleare (INFN) (Presti, 2015) [1]. Sixty parallel layers of the same fibers used in the tracker compose the RRD. The various layers are optically coupled to a MPPC array by means of wavelength shifting (WLS) fibers. The sensitive area of the two detectors is 9×9 cm2. The results of the measurements, acquired by the prototypes with CATANA (Cirrone, 2008) [2] proton beam, and a comparison with the simulations of the detectors are presented.

  12. Method and system for fiber optic determination of gas concentrations in liquid receptacles

    Science.gov (United States)

    Nguyen, Quang-Viet (Inventor)

    2008-01-01

    A system for determining gas compositions includes a probe, inserted into a source of gaseous material, the probe having a gas permeable sensor tip and being capable of sending and receiving light to and from the gaseous material, a sensor body, connected to the probe, situated outside of the source and a fiber bundle, connected to the sensor body and communicating light to and from the probe. The system also includes a laser source, connected to one portion of the fiber bundle and providing laser light to the fiber bundle and the probe a Raman spectrograph, connected to another portion of the fiber bundle, receiving light from the probe and filtering the received light into specific channels and a data processing unit, receiving and analyzing the received light in the specific channels and outputting concentration of specific gas species in the gaseous material based on the analyzed received light.

  13. Cost-effective fiber multiplexing system based on low coherence interferometers and application to temperature measurement

    Science.gov (United States)

    Jiang, Meng; Zhao, Zhongze; Li, Kun; Wang, Zeming; Zhan, Yage; Zhou, Hongying; Yang, Fu

    2016-12-01

    Based on the low-coherence interferometric principles, a cost-effective all-fiber Mach-Zehnder multiplexing system is proposed and demonstrated. The system consists of two interferometers: sensing interferometer and demodulation interferometer. By scanning an optical tunable delay line back and forth constantly with a stable speed, sensing fibers with different optical paths can be temporal interrogated. The system is experimentally proved to have a high performance with a good stability and low system noises. The multiplexing capacity of the system is also investigated. An experiment of measuring the surrounding temperature is carried out. A sensitivity of 12 μm/°C is achieved within the range of 20°C to 80°C. This low cost fiber multiplexing system has a potential application in the remote monitoring of temperature and strain in building structures, such as bridges and towers.

  14. A fiber-optical cable television system using a reflective semiconductor optical amplifier

    Science.gov (United States)

    Peng, P. C.; Shiu, K. C.; Liu, W. C.; Chen, K. J.; Lu, H. H.

    2013-02-01

    This investigation demonstrates a fiber-optical cable television system using a reflective semiconductor optical amplifier (RSOA) for uplink transmission. The downstream signal is cable television and the upstream signal is generated by remodulating the downstream signal via an RSOA with a radio-frequency signal. Favorable carrier-to-noise ratio, composite second-order, and composite triple beat are obtained for the downstream and the upstream signal is successfully transmitted over 60 km of single-mode fiber.

  15. Fiber-Optic Sensing System: Overview, Development and Deployment in Flight at NASA

    Science.gov (United States)

    Chan, Hon Man; Parker, Allen R.; Piazza, Anthony; Richards, W. Lance

    2015-01-01

    An overview of the research and technological development of the fiber-optic sensing system (FOSS) at the National Aeronautics and Space Administration Armstrong Flight Research Center (NASA AFRC) is presented. Theory behind fiber Bragg grating (FBG) sensors, as well as interrogation technique based on optical frequency domain reflectometry (OFDR) is discussed. Assessment and validation of FOSS as an accurate measurement tool for structural health monitoring is realized in the laboratory environment as well as large-scale flight deployment.

  16. Distributed optical fiber vibration sensor based on spectrum analysis of Polarization-OTDR system.

    Science.gov (United States)

    Zhang, Ziyi; Bao, Xiaoyi

    2008-07-07

    A fully distributed optical fiber vibration sensor is demonstrated based on spectrum analysis of Polarization-OTDR system. Without performing any data averaging, vibration disturbances up to 5 kHz is successfully demonstrated in a 1km fiber link with 10m spatial resolution. The FFT is performed at each spatial resolution; the relation of the disturbance at each frequency component versus location allows detection of multiple events simultaneously with different and the same frequency components.

  17. Effective enrichment of cholangiocarcinoma secretomes using the hollow fiber bioreactor culture system.

    Science.gov (United States)

    Weeraphan, Churat; Diskul-Na-Ayudthaya, Penchatr; Chiablaem, Khajeelak; Khongmanee, Amnart; Chokchaichamnankit, Daranee; Subhasitanont, Pantipa; Svasti, Jisnuson; Srisomsap, Chantragan

    2012-09-15

    The Northeastern region of Thailand is well known to have high incidence of bile duct cancer known as cholangiocarcinoma. So there is a continued need to improve diagnosis and treatment, and discovery of biomarkers for early detection of bile duct cancer should greatly improve treatment outcome for these patients. The secretome, a collection of proteins secreted from cells, is a useful source for identifying circulating biomarkers in blood secreted from cancer cells. Here a Hollow Fiber Bioreactor culture system was used for enrichment of cholangiocarcinoma secretomes, since this culture system mimics the dense three-dimensional microenvironment of the tumor found in vivo. Two-dimensional fluorescence difference gel electrophoresis using a sensitive Fluor saturation dye staining, followed by LC/MS/MS, was used to compare protein expression in the secretomes of cells cultured in the Hollow Fiber system and cells cultured in the monolayer culture system. For the first time, the 2D-patterns of cholangiocarcinoma secretomes from the two culture systems could be compared. The Hollow Fiber system improved the quality and quantity of cholangiocarcinoma secreted proteins compared to conventional monolayer system, showing less interference by cytoplasmic proteins and yielding more secreted proteins. Overall, 75 spots were analyzed by LC/MS/MS and 106 secreted proteins were identified. Two novel secreted proteins (C19orf10 and cystatin B) were found only in the Hollow Fiber system and were absent from the traditional monolayer culture system. Among the highly expressed proteins, 22 secreted soluble proteins were enriched by 5 fold in Hollow Fiber system compared to monolayer culture system. The Hollow Fiber system is therefore useful for preparing a wide range of proteins from low-abundance cell secretomes. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Distributed optical fiber perturbation sensing system based on Mach-Zehnder interferometer

    Institute of Scientific and Technical Information of China (English)

    Wengang WANG; Deming LIU; Hairong LIU; Qizhen SUN; Zhifeng SUN; Xu ZHANG; Ziheng XU

    2009-01-01

    A novel distributed optical fiber vibration-sensing system based on Mach-Zehnder interferometer has been designed and experimentally demonstrated. Firstly, the principle of Mach-Zehnder optical path interferometer technique is clarified. The output of the Mach-Zehnder interferometer is proportional to the phase shift induced by the perturbation. Secondly, the system consists of the laser diode (LD) as the light source, fiber, Mach-Zehnder optical interferometers as the sensing units, a 1×N star fiber-optic coupler, an N×1 fiber-optic coupler, a photodiode (PD) detector, and a computer used in signal processing. The entire monitoring region of this system is divided into several small zones, and each small monitoring zone is independent from each other. All of the small monitoring zones have their own sensing unit, which is defined by Mach-Zehnder optical interferometer. A series of sensing units are connected by the star fiber-optic couplers to form a whole sensing net. Thirdly, signal-processing techniques are subsequently used to calculate the phase shift to estimate whether intruders appear. The sensing system is able to locate the vibration signal simultaneously, includ-ing multiple vibrations at different positions, by employing the time-division multiplexed (TDM) technique. Finally, the operation performance of the proposed system is tested in the experiment lab with the conditions as follows: the number of the sensing units is 3, the length of the sensing fiber is 50 m, and the wavelength of the light diode is 1550nm. Based on these investigations, the fiber surrounding alert system is achieved. We have experimen-tally demonstrated that the sensing system can measure both the frequency and position of the vibration in real time, with a spatial positional resolution better than 50 m in an area of 1 km2.

  19. Design Ammonia Gas Detection System by Using Optical Fiber Sensor

    Directory of Open Access Journals (Sweden)

    Dr. Bushra. R. Mhdi

    2013-07-01

    Full Text Available Design study and construction of Ammonia gas detection using a fiber as a sensor to based on evanescent wave sensing technique was investigated. Multi-mode fiber type (PCS with core diameter (600μm and (50cm length used where plastic clad was removed by chemical etching for effective sensing area which coated with sol-gel film to enhance its absorption characteristics to evanescent wave around the optical spectrum emitted from halogen lamp measurements through different temperature rang (25-60oc with and without air using as a carrier to ammonia molecules are investigated. Finally sensing efficiency are monitored to ammonia gas it affected to different temperature and environmental condition are studied and our result are compatible to scientific publishes

  20. A hippocampal interneuron associated with the mossy fiber system.

    Science.gov (United States)

    Vida, I; Frotscher, M

    2000-02-01

    Network properties of the hippocampus emerge from the interaction of principal cells and a heterogeneous population of interneurons expressing gamma-aminobutyric acid (GABA). To understand these interactions, the synaptic connections of different types of interneurons need to be elucidated. Here we describe a type of inhibitory interneuron of the hippocampal CA3 region that has an axon coaligned with the mossy fibers. Whole-cell patch-clamp recordings, in combination with intracellular biocytin filling, were made from nonpyramidal cells of the stratum lucidum under visual control. Mossy fiber-associated (MFA) interneurons generated brief action potentials followed by a prominent after-hyperpolarization. Subsequent visualization revealed an extensive axonal arbor which was preferentially located in the stratum lucidum of CA3 and often invaded the hilus. The dendrites of MFA interneurons were mainly located in the strata radiatum and oriens, suggesting that these cells are primarily activated by associational and commissural fibers. Electron microscopic analysis showed that axon terminals of MFA interneurons established symmetric synaptic contacts predominantly on proximal apical dendritic shafts, and to a lesser degree, on somata of pyramidal cells. Synaptic contacts were also found on GABAergic interneurons of the CA3 region and putative mossy cells of the hilus. Inhibitory postsynaptic currents (IPSCs) elicited by MFA interneurons in simultaneously recorded pyramidal cells had fast kinetics (half duration, 3.6 ms) and were blocked by the GABA(A) receptor antagonist bicuculline. Thus, MFA interneurons are GABAergic cells in a position to selectively suppress the mossy fiber input, an important requirement for the recall of memory traces from the CA3 network.

  1. A hippocampal interneuron associated with the mossy fiber system

    OpenAIRE

    Vida, Imre; Frotscher, Michael

    2000-01-01

    Network properties of the hippocampus emerge from the interaction of principal cells and a heterogeneous population of interneurons expressing γ-aminobutyric acid (GABA). To understand these interactions, the synaptic connections of different types of interneurons need to be elucidated. Here we describe a type of inhibitory interneuron of the hippocampal CA3 region that has an axon coaligned with the mossy fibers. Whole-cell patch-clamp recordings, in combination with intracellular biocytin f...

  2. The effects of normal aging on myelinated nerve fibers in monkey central nervous system

    Directory of Open Access Journals (Sweden)

    Alan Peters

    2009-07-01

    Full Text Available The effects of aging on myelinated nerve fibers of the central nervous system are complex. Many myelinated nerve fibers in white matter degenerate and are lost, leading to some disconnections between various parts of the central nervous system. Other myelinated nerve fibers are affected differently, because only their sheaths degenerate, leaving the axons intact. Such axons are remyelinated by a series of internodes that are much shorter than the original ones and are composed of thinner sheaths. Thus the myelin-forming cells of the central nervous system, the oligodendrocytes, remain active during aging. Indeed, not only do these neuroglial cell remyelinate axons, with age they also continue to add lamellae to the myelin sheaths of intact nerve fibers, so that sheaths become thicker. It is presumed that the degeneration of myelin sheaths is due to the degeneration of the parent oligodendrocyte, and that the production of increased numbers of internodes as a consequence of remyelination requires additional oligodendrocytes. Whether there is a turnover of oligodendrocytes during life has not been studied in primates, but it has been established that over the life span of the monkey, there is a substantial increase in the numbers of oligodendrocytes. While the loss of some myelinated nerve fibers leads to some disconnections, the degeneration of other myelin sheaths and the subsequent remyelination of axons by shorter internodes slow down the rate conduction along nerve fibers. These changes affect the integrity and timing in neuronal circuits, and there is evidence that they contribute to cognitive decline.

  3. Experimental demonstration of 24-Gb/s CAP-64QAM radio-over-fiber system over 40-GHz mm-wave fiber-wireless transmission.

    Science.gov (United States)

    Zhang, Junwen; Yu, Jianjun; Chi, Nan; Li, Fan; Li, Xinying

    2013-11-04

    We propose and demonstrate a novel CAP-ROF system based on multi-level carrier-less amplitude and phase modulation (CAP) 64QAM with high spectrum efficiency for mm-wave fiber-wireless transmission. The performance of novel CAP modulation with high order QAM, for the first time, is investigated in the mm-wave fiber-wireless transmission system. One I/Q modulator is used for mm-wave generation and base-band signal modulation based on optical carrier suppression (OCS) and intensity modulation. Finally, we demonstrated a 24-Gb/s CAP-64QAM radio-over-fiber (ROF) system over 40-km stand single-mode-fiber (SMMF) and 1.5-m 38-GHz wireless transmission. The system operation factors are also experimentally investigated.

  4. A DFB Fiber Laser Sensor System with Ultra-High Resolution and Its Noise Analysis

    Institute of Scientific and Technical Information of China (English)

    Hao Xiao; Fang Li; Jun He; Yu-Liang Liu

    2008-01-01

    A distributed feedback fiber laser (DFB FL) sensor system with ultra-high resolution is described. The sensor is made by writing distributed feedback structures into a high gain active fiber, and the system employs an unbalanced Michelson interferometer to translate laser wavelength shifts induced by weak measurands into phase shifts. A digital phase generated carrier demodulation scheme is introduced to achieve ultra-high resolution interrogation. A detailed noise analysis of the system is presented, and it is shown that the system resolution is limited by the frequency noise of the DFB FL.

  5. A hybrid fiber-optic sensor system for condition monitoring of large scale wind turbine blades

    Science.gov (United States)

    Kim, Dae-gil; Kim, Hyunjin; Sampath, Umesh; Song, Minho

    2015-07-01

    A hybrid fiber-optic sensor system which combines fiber Bragg grating (FBG) sensors and a Michelson interferometer is suggested for condition monitoring uses of large scale wind turbine blades. The system uses single broadband light source to address both sensors, which simplifies the optical setup and enhances the cost-effectiveness of condition monitoring system. An athermal-packaged FBG is used to supply quasi-coherent light for the Michelson interferometer demodulation. For the feasibility test, different profiles of test strain, temperature and vibration have been applied to test structures, and successfully reconstructed with the proposed sensor system.

  6. Dispersive and nonlinear effects in high-speed reconfigurable WDM optical fiber communication systems

    Science.gov (United States)

    Yu, Changyuan

    Chromatic dispersion, polarization mode dispersion (PMD) and nonlinear effects are important issues on the physical layer of high-speed reconfigurable WDM optical fiber communication systems. For beyond 10 Gbit/s optical fiber transmission system, it is essential that chromatic dispersion and PMD be well managed by dispersion monitoring and compensation. One the other hand, dispersive and nonlinear effects in optical fiber systems can also be beneficial and has applications on pulse management, all-optical signal processing and network function, which will be essential for high bite-rate optical networks and replacing the expensive optical-electrical-optical (O/E/O) conversion. In this Ph.D. dissertation, we present a detailed research on dispersive and nonlinear effects in high-speed optical communication systems. We have demonstrated: (i) A novel technique for optically compensating the PMD-induced RF power fading that occurs in single-sideband (SSB) subcarrier-multiplexed systems. By aligning the polarization states of the optical carrier and the SSB, RF power fading due to all orders of PMD can be completely compensated. (ii) Chromatic-dispersion-insensitive PMD monitoring by using a narrowband FBG notch filter to recover the RF clock power for 10Gb/s NRZ data, and apply it as a control signal for PMD compensation. (iii) Chirp-free high-speed optical pulse generation with a repetition rate of 160 GHz (which is four times of the frequency of the electrical clock) using a phase modulator and polarization maintaining (PM) fiber. (iv) Polarization-insensitive all-optical wavelength conversion based on four-wave mixing in dispersion-shifted fiber (DSF) with a fiber Bragg grating and a Faraday rotator mirror. (v) Width-tunable optical RZ pulse train generation based on four-wave mixing in highly-nonlinear fiber. By electrically tuning the delay between two pump pulse trains, the pulse-width of a generated pulse train is continuously tuned. (vi) A high-speed all

  7. Optical signal monitoring in phase modulated optical fiber transmission systems

    Science.gov (United States)

    Zhao, Jian

    Optical performance monitoring (OPM) is one of the essential functions for future high speed optical networks. Among the parameters to be monitored, chromatic dispersion (CD) is especially important since it has a significant impact on overall system performance. In this thesis effective CD monitoring approaches for phase-shift keying (PSK) based optical transmission systems are investigated. A number of monitoring schemes based on radio frequency (RF) spectrum analysis and delay-tap sampling are proposed and their performance evaluated. A method for dispersion monitoring of differential phase-shift keying (DPSK) signals based on RF power detection is studied. The RF power spectrum is found to increase with the increase of CD and decrease with polarization mode dispersion (PMD). The spectral power density dependence on CD is studied theoretically and then verified through simulations and experiments. The monitoring sensitivity for nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) and return-to-zero differential phase-shift keying (RZ-DPSK) based systems can reach 80ps/nm/dB and 34ps/nm/dB respectively. The scheme enables the monitoring of differential group delay (DGD) and CD simultaneously. The monitoring sensitivity of CD and DGD can reach 56.7ps/nm/dB and 3.1ps/dB using a bandpass filter. The effects of optical signal-to-noise ratio (OSNR), DGD, fiber nonlinearity and chirp on the monitoring results are investigated. Two RF pilot tones are employed for CD monitoring of DPSK signals. Specially selected pilot tone frequencies enable good monitoring sensitivity with minimum influence on the received signals. The dynamic range exceeding 35dB and monitoring sensitivity up to 9.5ps/nm/dB are achieved. Asynchronous sampling technique is employed for CD monitoring. A signed CD monitoring method for 10Gb/s NRZ-DPSK and RZ-DPSK systems using asynchronous delay-tap sampling technique is studied. The demodulated signals suffer asymmetric waveform distortion if

  8. Experimental research of optical fiber hydrogen gas sensing system based on palladium-silver alloy

    Science.gov (United States)

    Cui, Lu-jun; Zhou, Gao-feng; Li, Zheng-feng; Cao, Yan-long

    2016-11-01

    A novel optical fiber hydrogen sensing system based on palladium (Pd) and sliver (Ag) is proposed. By direct current (DC) magnetron process, Pd/Ag alloy ultra-thin films were deposited on the substrate to eliminate the hydrogen embrittlement of sensor based on pure Pd. Several samples with different thin film thicknesses were fabricated at different substrate temperatures and tested in the optical fiber hydrogen sensor setup. We do a series of experiments for obtaining optimum sputtering parameters, such as optimum sputtering temperature and thickness of Pd/Ag alloy film. The humidity effect and reliability experiment for the optical fiber hydrogen gas sensor are reported in detail. The testing results demonstrate the Pd/Ag alloy is a promising material for optical fiber hydrogen gas sensor.

  9. Water Fibers

    CERN Document Server

    Douvidzon, Mark L; Martin, Leopoldo L; Carmon, Tal

    2016-01-01

    Fibers constitute the backbone of modern communication and are used in laser surgeries; fibers also genarate coherent X-ray, guided-sound and supercontinuum. In contrast, fibers for capillary oscillations, which are unique to liquids, were rarely considered in optofluidics. Here we fabricate fibers by water bridging an optical tapered-coupler to a microlensed coupler. Our water fibers are held in air and their length can be longer than a millimeter. These hybrid fibers co-confine two important oscillations in nature: capillary- and electromagnetic-. We optically record vibrations in the water fiber, including an audio-rate fundamental and its 3 overtones in a harmonic series, that one can hear in soundtracks attached. Transforming Micro-Electro-Mechanical-Systems [MEMS] to Micro-Electro-Capillary-Systems [MECS], boosts the device softness by a million to accordingly improve its response to minute forces. Furthermore, MECS are compatible with water, which is a most important liquid in our world.

  10. Modern Fiber Optic Submarine Cable Telecommunication Systems Planning for Explosive Bandwidth Needs at Different Deployment Depths

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-10-01

    Full Text Available The explosive bandwidth needs, especially in the inter data center market, have pushed transmission data rates to 100 Gbit/sec and beyond. Current terrestrial fibers are inadequate for long haul, high bandwidth deployments. To solve these problems a new fiber is introduced for terrestrial high bandwidth deployments: different polymeric core fibers with enlarged effective area with a significant optical signal to noise ratio improvement over other conventional terrestrial single mode fibers. To ensure the new fiber may be deployed robustly a new coating structure was employed. A rigorous cable structure was then chosen for evaluation. Based on experimental data, both the deep ocean water temperature and pressure are tailored as functions of the water depth. As well as the product of the transmitted bit rate and the repeater spacing is processed over wide ranges of the affecting parameters. It is taken into account the estimation of the total cost of the submarine fiber cable system for transmission technique under considerations. The system capacity as well as the spectral losses, and the dispersion effects are parametrically investigated over wide range ranges of the set of affecting parameters {wavelength, ocean depth (and consequently the ocean pressure and temperature, and the chemical structure}.

  11. Modern Fiber Optic Submarine Cable Telecommunication Systems Planning for Explosive Bandwidth Needs at Different Deployment Depths

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-05-01

    Full Text Available The explosive bandwidth needs, especially in the inter data center market, have pushed transmission data rates to 100 Gbit/sec and beyond. Current terrestrial fibers are inadequate for long haul, high bandwidth deployments. To solve these problems a new fiber is introduced for terrestrial high bandwidth deployments: different polymeric core fibers with enlarged effective area with a significant optical signal to noise ratio improvement over other conventional terrestrial single mode fibers. To ensure the new fiber may be deployed robustly a new coating structure was employed. A rigorous cable structure was then chosen for evaluation. Based on experimental data, both the deep ocean water temperature and pressure are tailored as functions of the water depth. As well as the product of the transmitted bit rate and the repeater spacing is processed over wide ranges of the affecting parameters. It is taken into account the estimation of the total cost of the submarine fiber cable system for transmission technique under considerations. The system capacity as well as the spectral losses, and the dispersion effects are parametrically investigated over wide range ranges of the set of affecting parameters {wavelength, ocean depth (and consequently the ocean pressure and temperature, and the chemical structure}.

  12. A New High-Speed Foreign Fiber Detection System with Machine Vision

    Directory of Open Access Journals (Sweden)

    Zhiguo Chen

    2010-01-01

    Full Text Available A new high-speed foreign fiber detection system with machine vision is proposed for removing foreign fibers from raw cotton using optimal hardware components and appropriate algorithms designing. Starting from a specialized lens of 3-charged couple device (CCD camera, the system applied digital signal processor (DSP and field-programmable gate array (FPGA on image acquisition and processing illuminated by ultraviolet light, so as to identify transparent objects such as polyethylene and polypropylene fabric from cotton tuft flow by virtue of the fluorescent effect, until all foreign fibers that have been blown away safely by compressed air quality can be achieved. An image segmentation algorithm based on fast wavelet transform is proposed to identify block-like foreign fibers, and an improved canny detector is also developed to segment wire-like foreign fibers from raw cotton. The procedure naturally provides color image segmentation method with region growing algorithm for better adaptability. Experiments on a variety of images show that the proposed algorithms can effectively segment foreign fibers from test images under various circumstances.

  13. Sub-pixel processing for super-resolution scanning imaging system with fiber bundle coupling

    Institute of Scientific and Technical Information of China (English)

    Bowen An; Bingbin Xue; Shengda Pan; Guilin Chen

    2011-01-01

    A multilayer fiber bundle is used to couple the image in a remote sensing imaging system. The object image passes through all layers of the fiber bundle in micro-scanning mode. The malposition of adjacent layers arranged in a hexagonal pattern is at sub-pixel scale. Therefore, sub-pixel processing can be applied to improve the spatial resolution. The images coupled by the adjacent layer fibers are separated, and subsequently, the intermediate image is obtained by histogram matching based on one of the separated image called base image. Finally, the intermediate and base images are processed in the frequency domain. The malposition of the adjacent layer fiber is converted to the phase difference in Fourier transform. Considering the limited sensitivity of the experimental instruments and human sight, the image is set as a band-limited signal and the interpolation function of image fusion is found. The results indicate that a super-resolution image with ultra-high spatial resolution is obtained.%@@ A multilayer fiber bundle is used to couple the image in a remote sensing imaging system.The object image passes through all layers of the fiber bundle in micro-scanning mode.The malposition of adjacent layers arranged in a hexagonal pattern is at sub-pixel scale.

  14. Development of Optical Fiber-Based Daylighting System and Its Comparison

    Directory of Open Access Journals (Sweden)

    Irfan Ullah

    2015-07-01

    Full Text Available Fiber-optic daylighting systems have been shown to be a promising and effective way to transmit sunlight in the interior space whilst reducing electric lighting energy consumption. To increase efficiency in terms of providing uniform illumination in the interior, the current need is to illuminate optical fiber-bundle with uniform light flux. To this end, we propose a method for achieving collimated light, which illuminates the fiber-bundle uniformly. Light is collected through a parabolic concentrator and focused toward a collimating lens, which distributes the light over each optical fiber. An optics diffusing structure is utilized at the end side of the fiber bundle to spread light in the interior. The results clearly reveal that the efficiency in terms of uniform illumination, which also reduces the heat problem for optical fibers, is improved. Furthermore, a comparison study is conducted between current and previous approaches. As a result, the proposed daylighting system turns out convenient in terms of energy saving and reduction in greenhouse gas emissions.

  15. Miniature fiber Bragg grating sensor interrogator (FBG-Transceiver) system for use in aerospace and automotive health monitoring systems

    Science.gov (United States)

    Mendoza, Edgar A.; Kempen, Cornelia; Panahi, Allan; Lopatin, Craig

    2007-09-01

    Fiber Bragg grating sensors (FBGs) have gained rapid acceptance in aerospace and automotive structural health monitoring applications for the measurement of strain, stress, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion distributed at multiple locations within the structure using a single fiber element. The most prominent advantages of FBGs are: small size and light weight, multiple FBG transducers on a single fiber, and immunity to radio frequency interference. A major disadvantage of FBG technology is that conventional state-of-the-art fiber Bragg grating interrogation systems are typically bulky and heavy bench top instruments that are assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the need for a compact FBG interrogation system, this paper describes recent progress towards the development of a miniature fiber Bragg grating sensor interrogator (FBG-Transceiver TM) system based on multi-channel integrated optic sensor (InOSense) microchip technology. The hybrid InOSense microchip technology enables the integration of all of the functionalities, both passive and active, of conventional bench top FBG sensor interrogators systems, packaged in a miniaturized, low power operation, 2-cm x 5-cm small form factor (SFF) package suitable for the long-term structural health monitoring in applications where size, weight, and power are critical for operation. The sponsor of this program is NAVAIR under a DOD SBIR contract.

  16. Transmission Performance Analysis of Fiber Optical Parametric Amplifiers for WDM System

    Directory of Open Access Journals (Sweden)

    Xiaohong Jiang

    2009-01-01

    Full Text Available A numerical analysis is presented on the long-haul wavelength-division multiplexing (WDM transmission system employing fiber-optic parametric amplifier (FOPA cascades based on one-pump FOPA model with Raman Effect taken into account. The end-to-end equalization scheme is applied to optimize the system features in terms of proper output powers and signal-to-noise ratios (SNRs in all the channels. The numerical results show that—through adjusting the fiber spans along with the number of FOPAs as well as the channel powers at the terminals in a prescribed way—the transmission distance and system performance can be optimized. By comparing the results generated by different lengths of fiber span, we come to the optimal span length to achieve the best transmission performance. Furthermore, we make a comparison among the long-haul WDM transmission systems employing different inline amplifiers, namely, FOPA, erbium-doped fiber amplifier (EDFA, and Fiber Raman Amplifier (FRA. FOPA demonstrates its advantage over the other two in terms of system features.

  17. Design considerations for a fiber optic communications network for power systems

    Energy Technology Data Exchange (ETDEWEB)

    Kirkham, H.; Johnston, A.R. [Jet Propulsion Lab., Pasadena, CA (United States); Allen, G.D. [American Electric Power Service Corp., Columbus, OH (United States)

    1993-08-01

    The design of a fiber optic communication network for monitoring and control in power systems is discussed. It is shown that by appropriate choice of protocols, a fault-tolerant system can be built that operates in any arbitrary configuration. Since the network is based on fiber optics, it can be made fast enough for substation monitoring and control. In this application, a relatively small number of cables is required to implement a high reliability system. The network can also be used for distribution automation. In this application the network is required to reach all parts of the power system, and the fiber cable itself becomes a significant fraction of the cost of communications. However, since many applications can be supported at once, the cost per function can be reasonable.

  18. Design and analysis of spectral beam combining system for fiber lasers based on a concave grating

    Institute of Scientific and Technical Information of China (English)

    WU Zhuo-liang; ZHAO Shang-hong; CHU Xing-chun; ZHANG Xi; ZHAN Sheng-bao; MA Li-hua

    2012-01-01

    Anovel fiber laser spectral beam combining scheme based on a concave grating is presented.The principle of the presented system is analyzed,and a concave grating with blazed structure for spectral beam combining is designed.The combining potential of the system is analyzed,and the results show that 39 Yb-doped fiber laser can be spectrally beam combined via the designed system.By using scalar diffraction theory,the combining effect of the system is analyzed.The results show that the diffraction efficiency of the designed concave grating is higher than 72% over the whole gain bandwidth,and the combining efficiency is 73.4%.With output power of 1 kW for individual fiber laser,combined power of 28.6 kW can be achieved.

  19. Design and simulation of GRIN objective lenses for an imaging fiber based speckle metrology system

    Science.gov (United States)

    Prabhathan, P.; Guru Prasad, A. S.; Haridas, Aswin; Chan, Kelvin H. K.; Murukeshan, V. M.

    2016-11-01

    Gradient-Index (GRIN) lenses are characterized by its small diameter and length, enabling them to be an effective lens for an integrated probe based imaging system. For a speckle-based surface metrology system, the imaging lens plays an important role in deciding the statistical dimensions of the speckles. In such cases, the design and simulation of the lens system would be a key process to better the performance of the lensed imaging fiber probe. In this context, this paper focuses on the design of lensed fiber probes for a speckle-based surface metrological imaging system that can find intra cavity interrogation applications. Different optical properties of GRIN lenses and imaging fibers are considered while designing the final probe distal end to meet the targeted specifications. Singlet GRIN lens configuration is analyzed for a front view configuration and a parameter optimization has been carried out to obtain the specifications including the field-of-view, resolution, working distance and magnification.

  20. An all fiber-optic multi-parameter structure health monitoring system.

    Science.gov (United States)

    Hu, Chennan; Yu, Zhihao; Wang, Anbo

    2016-09-01

    In this work, we present an all fiber-optics based multi-parameter structure health monitoring system, which is able to monitor strain, temperature, crack and thickness of metal structures. This system is composed of two optical fibers, one for laser-acoustic excitation and the other for acoustic detection. A nano-second 1064 nm pulse laser was used for acoustic excitation and a 2 mm fiber Bragg grating was used to detect the acoustic vibration. The feasibility of this system was demonstrated on an aluminum test piece by the monitoring of the temperature, strain and thickness changes, as well as the appearance of an artificial crack. The multiplexing capability of this system was also preliminarily demonstrated.

  1. A Robust Distributed Multipoint Fiber Optic Gas Sensor System Based on AGC Amplifier Structure

    Directory of Open Access Journals (Sweden)

    Cunguang Zhu

    2016-07-01

    Full Text Available A harsh environment-oriented distributed multipoint fiber optic gas sensor system realized by automatic gain control (AGC technology is proposed. To improve the photoelectric signal reliability, the electronic variable gain can be modified in real time by an AGC closed-loop feedback structure to compensate for optical transmission loss which is caused by the fiber bend loss or other reasons. The deviation of the system based on AGC structure is below 4.02% when photoelectric signal decays due to fiber bending loss for bending radius of 5 mm, which is 20 times lower than the ordinary differential system. In addition, the AGC circuit with the same electric parameters can keep the baseline intensity of signals in different channels of the distributed multipoint sensor system at the same level. This avoids repetitive calibrations and streamlines the installation process.

  2. Results of a portable fiber-optic weigh-in-motion system

    Energy Technology Data Exchange (ETDEWEB)

    Muhs, J.D.; Jordan, J.K.; Scudiere, M.B.; Tobin, K.W. Jr.

    1991-01-01

    Experimental results on a portable, low speed fiber-optic weigh-in motion system are described that demonstrate the applicability of fiber-optic-based sensors in transportation, defense, and law enforcement applications where accurate weight determination of moving vehicles is necessary. Results are given on the systems' dynamic range (0.1--30 metric tons), velocity range (up to 5 km/h), accuracy error (0.5--3.0%), and repeatability. Also included in the paper is a discussion of the sources of error associated with low-speed weigh-in-motion systems and methods of minimizing these errors for practical deployment.

  3. Results of a portable fiber optic weigh-in-motion system

    Science.gov (United States)

    Muhs, Jeffrey D.; Jordan, John K.; Scudiere, Matthew B.; Tobin, Kenneth W., Jr.

    1991-12-01

    Experimental results on a portable, low-speed fiber-optic weigh-in-motion system are described that demonstrate the applicability of fiber-optic-based sensors in transportation, defense, and law enforcement applications where accurate weight determination of moving vehicles is necessary. Results are given on the systems' dynamic range (0.1 - 30 metric tons), velocity range (up to 5 km/h), accuracy error (0.5 - 3.0%), and repeatability. Also included in the paper is a discussion of the sources of error associated with low speed weigh-in-motion systems and methods of minimizing these errors for practical deployment.

  4. Results of a portable fiber-optic weigh-in-motion system

    Energy Technology Data Exchange (ETDEWEB)

    Muhs, J.D.; Jordan, J.K.; Scudiere, M.B.; Tobin, K.W. Jr.

    1991-12-31

    Experimental results on a portable, low speed fiber-optic weigh-in motion system are described that demonstrate the applicability of fiber-optic-based sensors in transportation, defense, and law enforcement applications where accurate weight determination of moving vehicles is necessary. Results are given on the systems` dynamic range (0.1--30 metric tons), velocity range (up to 5 km/h), accuracy error (0.5--3.0%), and repeatability. Also included in the paper is a discussion of the sources of error associated with low-speed weigh-in-motion systems and methods of minimizing these errors for practical deployment.

  5. Acquired anhidrosis associated with systemic sarcoidosis: Quantification of nerve fibers around eccrine glands by confocal microscopy.

    Science.gov (United States)

    Nishida, M; Namiki, T; Sone, Y; Hashimoto, T; Tokoro, S; Hanafusa, T; Yokozeki, H

    2017-08-10

    Neurological disorders can cause hypohidrosis and/or anhidrosis by disturbing either the central or the peripheral nervous systems.(1-3) Although a syringotropic variant of cutaneous sarcoidosis causes dysfunction of sweating, systemic sarcoidosis rarely causes hypohidrosis or anhidrosis.(4,5) Here we present a novel case of an acquired anhidrosis in a patient with systemic sarcoidosis. Furthermore, we developed a novel methodology to quantify nerve fibers around eccrine glands using confocal microscopy and found that nerve fibers around eccrine glands in anhidrotic areas are significantly decreased compared to hidrotic areas. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  6. A Space-Based Optical Communication System Utilizing Fiber Optics

    Science.gov (United States)

    1989-11-09

    single mode elliptic core fibers," Opt. Commun., 49, 3, 178-183 (1984). 35 15. B.J. Klein and J.J. Degnan, " Optical antenna gain. 1: Transmitting...antennas," Appl. Opt., 13,9,2134- 2141 (1974). 16. B.J. Klein and J.J. Degnan, " Optical antenna gain. 2: Receiving antennas," Appl. Opt., 13, 10,2397- 2401...1974). 17. B.J. Klein and J.J. Degnan, " Optical antenna gain. 3: The effect of secondary element support struts on transmitter gain," Appl. Opt., 15

  7. Optical fiber sources and transmission controls for multi-Tb/s systems

    Science.gov (United States)

    Nowak, George Adelbert

    The accelerating demand for bandwidth capacity in backbone links of terrestrial communications systems is projected to exceed 1Tb/s by 2002. Lightwave carrier frequencies and fused-silica optical fibers provide the natural combination of high passband frequencies and low- loss medium to satisfy this evolving demand for bandwidth capacity. This thesis addresses three key technologies for enabling multi-Tb/s optical fiber communication systems. The first technology is a broadband source based on supercontinuum generation in optical fiber. Using a single modelocked laser with output pulsewidths of 0.5psec pulses, we generate in ~2m of dispersion-shifted fiber more that 200nm of spectral continuum in the vicinity of 1550nm that is flat to better than +/- 0.5 dB over more than 60nm. The short fiber length prevents degradation of timing jitter of the seed pulses and preserves coherence of the continuum by inhibiting environmental perturbations and mapping of random noise from the vicinity of the input pulse across the continuum. Through experiments and simulations, we find that the continuum characteristics result from 3rd order dispersion effects on higher-order soliton compression. We determine optimal fiber properties to provide desired continuum broadness and flatness for given input pulsewidth and energy conditions. The second technology is a novel delay-shifted nonlinear optical loop mirror (DS-NOLM) that performs a transmission control function by serving as an intensity filter and frequency compensator for 4ps soliton transmission over 75km of standard dispersion fiber, with 25km spacing between amplifiers, by filtering the dispersive waves and compensating for Raman-induced soliton self-frequency shift. The third technology is all-fiber wavelength conversion employing induced modulational instability. We obtain wavelength conversion over 40nm with a peak conversion efficiency of 28dB using 600mW pump pulses in 720m of high-nonlinearity optical fiber. We show

  8. Detection and localization of building insulation faults using optical-fiber DTS system

    Science.gov (United States)

    Papes, Martin; Liner, Andrej; Koudelka, Petr; Siska, Petr; Cubik, Jakub; Kepak, Stanislav; Jaros, Jakub; Vasinek, Vladimir

    2013-05-01

    Nowadays the trends in the construction industry are changing at an incredible speed. The new technologies are still emerging on the market. Sphere of building insulation is not an exception as well. One of the major problems in building insulation is usually its failure, whether caused by unwanted mechanical intervention or improper installation. The localization of these faults is quite difficult, often impossible without large intervention into the construction. As a proper solution for this problem might be utilization of Optical-Fiber DTS system based on stimulated Raman scattering. Used DTS system is primary designed for continuous measurement of the temperature along the optical fiber. This system is using standard optical fiber as a sensor, which brings several advantages in its application. First, the optical fiber is relatively inexpensive, which allows to cover a quite large area for a small cost. The other main advantages of the optical fiber are electromagnetic resistance, small size, safety operation in inflammable or explosive area, easy installation, etc. This article is dealing with the detection and localization of building insulation faults using mentioned system.

  9. Mutual Information as a Figure of Merit for Optical Fiber Systems

    CERN Document Server

    Fehenberger, Tobias

    2014-01-01

    Advanced channel decoders rely on soft-decision decoder inputs for which mutual information (MI) is the natural figure of merit. In this paper, we analyze an optical fiber system by evaluating MI as the maximum achievable rate of transmission of such a system. MI is estimated by means of histograms for which the correct bin number is determined in a blind way. The MI estimate obtained this way shows excellent accuracy in comparison with the true MI of 16-state quadrature amplitude modulation (QAM) over an additive white Gaussian noise channel with additional phase noise, which is a simplified model of a nonlinear optical fiber channel. We thereby justify to use the MI estimation method to accurately estimate the MI of an optical fiber system. In the second part of this work, a transoceanic fiber system with 6000 km of standard single-mode fiber is simulated and its MI determined. Among rectangular QAMs, 16-QAM is found to be the optimal modulation scheme for this link as to performance in terms of MI and requ...

  10. Linearization Technologies for Broadband Radio-Over-Fiber Transmission Systems

    Directory of Open Access Journals (Sweden)

    Xiupu Zhang

    2014-11-01

    Full Text Available Linearization technologies that can be used for linearizing RoF transmission are reviewed. Three main linearization methods, i.e. electrical analog linearization, optical linearization, and electrical digital linearization are presented and compared. Analog linearization can be achieved using analog predistortion circuits, and can be used for suppression of odd order nonlinear distortion components, such as third and fifth order. Optical linearization includes mixed-polarization, dual-wavelength, optical channelization and the others, implemented in optical domain, to suppress both even and odd order nonlinear distortion components, such as second and third order. Digital predistortion has been a widely used linearization method for RF power amplifiers. However, digital linearization that requires analog to digital converter is severely limited to hundreds of MHz bandwidth. Instead, analog and optical linearization provide broadband linearization with up to tens of GHz. Therefore, for broadband radio over fiber transmission that can be used for future broadband cloud radio access networks, analog and optical linearization are more appropriate than digital linearization. Generally speaking, both analog and optical linearization are able to improve spur-free dynamic range greater than 10 dB over tens of GHz. In order for current digital linearization to be used for broadband radio over fiber transmission, the reduced linearization complexity and increased linearization bandwidth are required. Moreover, some digital linearization methods in which the complexity can be reduced, such as Hammerstein type, may be more promising and require further investigation.

  11. Development of fiber optic sensor for fluid flow of astronauts’ life-support system

    Science.gov (United States)

    Shachneva, E. A.; Murashkina, T. I.

    2016-08-01

    This paper proposes a fiber optic sensor consumption (volume, speed) of liquids in life-support systems of astronauts, as well as offers a simple method and apparatus for reproducing the parameters of fluid flow needed in research, yustiovke and adjusting the optical sensor system.

  12. Advanced Fiber Optic-Based Sensing Technology for Unmanned Aircraft Systems

    Science.gov (United States)

    Richards, Lance; Parker, Allen R.; Piazza, Anthony; Ko, William L.; Chan, Patrick; Bakalyar, John

    2011-01-01

    This presentation provides an overview of fiber optic sensing technology development activities performed at NASA Dryden in support of Unmanned Aircraft Systems. Examples of current and previous work are presented in the following categories: algorithm development, system development, instrumentation installation, ground R&D, and flight testing. Examples of current research and development activities are provided.

  13. An evaluation of fiber optic intrusion detection systems in interior applications

    Energy Technology Data Exchange (ETDEWEB)

    Vigil, J.T.

    1994-03-01

    This report discusses the testing and evaluation of four commercially available fiber optic intrusion detection systems. The systems were tested under carpet-type matting and in a vaulted ceiling application. This report will focus on nuisance alarm data and intrusion detection results. Tests were conducted in a mobile office building and in a bunker.

  14. Development of fiber-optic current sensing technique and its applications in electric power systems

    Science.gov (United States)

    Kurosawa, Kiyoshi

    2014-03-01

    This paper describes the development and applications of a fiber-optic electric current sensing technique with the stable properties and compact, simple, and flexible structure of the sensing device. The special characteristics of the sensors were achieved by use of the special low birefringence fiber as the Faraday-effect sensing element and were also achieved with creation of sensing schemes which matched with the features of the fiber. Making use of the excellent features of the sensing technique, various current monitoring devices and systems were developed and applied practically for the control and maintenance in the electric power facility. In this paper, the design and performance of the sensing devices are introduced first. After that, examples of the application systems practically applied are also introduced, including fault section/point location systems for power transmission cable lines.

  15. Fiber-optic project-fringe interferometry with sinusoidal phase modulating system

    Science.gov (United States)

    Zhang, Fukai; Duan, Fajie; Lv, Changrong; Duan, Xiaojie; Bo, En; Feng, Fan

    2013-06-01

    A fiber-optic sinusoidal phase-modulating (SPM) interferometer for fringe projection is presented. The system is based on the SPM technique and makes use of the Mach-Zehnder interferometer structure and Young's double pinhole interference principle to achieve interference fringe projection. A Michelson interferometer, which contains the detection of Fresnel reflection on its fiber end face and interference at one input port of a 3 dB coupler, is utilized to achieve feedback precise control of the fringe phase, which is sensitive to phase drifting produced by the nature of the fiber. The phase diversity for the closed-loop SPM system can be real-time measured with a precision of 3 mrad. External disturbances mainly caused by temperature fluctuations can be reduced to 57 mrad for the fringe map. The experimental results have shown the usefulness of the system.

  16. Distributed fiber optic interferometric geophone system based on draw tower gratings

    Science.gov (United States)

    Xu, Ruquan; Guo, Huiyong; Liang, Lei

    2017-09-01

    A distributed fiber optic interferometric geophone array based on draw tower grating (DTG) array is proposed. The DTG geophone array is made by the DTG array fabricated based on a near-contact exposure through a phase mask during the fiber drawing process. A distributed sensing system with 96 identical DTGs in an equal separation of 20 m and an unbalanced Michelson interferometer for vibration measurement has been experimentally validated compared with a moving-coil geophone. The experimental results indicate that the sensing system can linearly demodulate the phase shift. Compared with the moving coil geophone, the fiber optic sensing system based on DTG has higher signal-to-noise ratio at low frequency.

  17. Novel systems for tailored neurotrophic factor release based on hydrogel and resorbable glass hollow fibers.

    Science.gov (United States)

    Novajra, G; Tonda-Turo, C; Vitale-Brovarone, C; Ciardelli, G; Geuna, S; Raimondo, S

    2014-03-01

    A novel system for the release of neurotrophic factor into a nerve guidance channel (NGC) based on resorbable phosphate glass hollow fibers (50P2O5-30CaO-9Na2O-3SiO2-3MgO-2.5K2O-2.5TiO2 mol%) in combination with a genipin-crosslinked agar/gelatin hydrogel (A/G_GP) is proposed. No negative effect on the growth of neonatal olfactory bulb ensheathing cell line (NOBEC) as well as on the expression of pro- and anti-apoptotic proteins was measured in vitro in the presence of fiber dissolution products in the culture medium. For the release studies, fluorescein isothiocyanate-dextran (FD-20), taken as growth factor model molecule, was solubilized in different media and introduced into the fiber lumen exploiting the capillary action. The fibers were filled with i) FD-20/phosphate buffered saline (PBS) solution, ii) FD-20/hydrogel solution before gelation and iii) hydrogel before gelation, subsequently lyophilized and then filled with the FD-20/PBS solution. The different strategies used for the loading of the FD-20 into the fibers resulted in different release kinetics. A slower release was observed with the use of A/G_GP hydrogel. At last, poly(ε-caprolactone) (PCL) nerve guides containing the hollow fibers and the hydrogel have been fabricated.

  18. Fiber Optical Cable and Connector System (FOCCoS) for PFS/Subaru

    CERN Document Server

    de Oliveira, Antonio Cesar; de Arruda, Márcio V; Marrara, Lucas Souza; Santos, Leandro H dos; Ferreira, Décio; Santos, Jesulino B dos; Rosa, Josimar A; Junior, Orlando V; Pereira, Jeferson M; Castilho, Bruno; Gneiding, Clemens; Junior, Laerte S; de Oliveira, Claudia M; Gunn, James E; Ueda, Akitoshi; Takato, Naruhisa; Shimono, Atsushi; Sugai, Hajime; Karoji, Hiroshi; Kimura, Masahiko; Tamura, Naoyuki; Wang, Shiang-Yu; Murray, Graham; Mignant, David Le; Madec, Fabrice; Jaquet, Marc; Vives, Sebastien; Fisher, Charlie; Braun, David; Schwochert, Mark; Reiley, Daniel J

    2014-01-01

    FOCCoS, Fiber Optical Cable and Connector System, has the main function of capturing the direct light from the focal plane of Subaru Telescope using optical fibers, each one with a microlens in its tip, and conducting this light through a route containing connectors to a set of four spectrographs. The optical fiber cable is divided in 3 different segments called Cable A, Cable B and Cable C. Multi-fibers connectors assure precise connection among all optical fibers of the segments, providing flexibility for instrument changes. To assure strong and accurate connection, these sets are arranged inside two types of assemblies: the Tower Connector, for connection between Cable C and Cable B; and the Gang Connector, for connection between Cable B and Cable A. Throughput tests were made to evaluate the efficiency of the connections. A lifetime test connection is in progress. Cable C is installed inside the PFI, Prime Focus Instrument, where each fiber tip with a microlens is bonded to the end of the shaft of a 2-sta...

  19. Non-invasive image-guided laser microsurgery by a dual-wavelength fiber laser and an integrated fiber-optic multi-modal system.

    Science.gov (United States)

    Tsai, Meng-Tsan; Li, Dean-Ru; Chan, Ming-Che

    2016-10-15

    A new approach to non-invasive image-guided laser micro-treatment is demonstrated by a dual-wavelength fiber laser source and an integrated fiber-based multi-modal system. The fiber-based source, operated in 1.55 and 1.2 μm simultaneously, was directly connected to an integrated fiber-based multi-modal system for imaging and laser micro-treatment at the same time. The 1.2 μm radiations, within the 1.2-1.35 μm bio-penetration window of skin, were utilized for spectral domain optical coherence tomography imaging. The 1.55 μm radiations, highly absorptive to waters, were utilized for laser microsurgery. The new approach, which is simple in configuration and accurately controls the positions and exposure time of the laser microsurgery, shows great promises for future clinical applications.

  20. Toward practical application of fiber optical parametric amplifiers in optical communication systems

    Science.gov (United States)

    Wong, Kin-Yip

    One of the most powerful techniques in fiber optical communication systems is wave-length division multiplexing (WDM). By utilizing the large (˜300 nm), low-loss (0.2--0.4 dB/km) transmission bandwidth, a single fiber can transmit many wavelengths. One fiber can potentially support transmission of tens of terabits per second of information over thousands of kilometers, to meet the exponentially-growing capacity demand. One of the key components for WDM systems is the optical amplifier; currently the most widely used optical amplifier is the erbium-doped fiber amplifier (EDFA). However, its bandwidth and operating wavelength are limited. To mitigate the bandwidth limitation of EDFAs, alternative optical amplifiers have been investigated, and one of the most promising candidates is the fiber optical parametric amplifier (OPA). Fiber OPAs are based on the third-order nonlinear susceptibility chi (3) in fiber. They can exhibit large bandwidth, and may find applications as optical amplifiers for WDM transmission. They also generate another wavelength, called idler, which contains the same modulation information as the input signal, with an inverted spectrum. This phase-conjugated idler can be used not only for wavelength conversion in WDM networks, but also for mid-span spectral inversion (MSSI) which can combat fiber dispersion, and even some of the detrimental fiber nonlinearities. In this dissertation, a record high-performance fiber OPA with 60 dB signal gain, and a parametric wavelength converter with 40 dB of conversion gain and 3.8 dB of noise figure are experimentally demonstrated. An OPA with 92% pump depletion is analyzed theoretically and demonstrated experimentally. Polarization-independent OPA, both in one-pump and two-pump configurations are investigated. The differences between the two configurations are discussed and other solutions are also proposed to address some issues of linear orthogonal two-pump OPA. In addition, the applications of OPA: as a

  1. The measurement system of birefringence and Verdet constant of optical fiber

    Science.gov (United States)

    Huang, Yi; Chen, Li; Guo, Qiang; Pang, Fufei; Wen, Jianxiang; Shang, Yana; Wang, Tingyun

    2013-12-01

    The Faraday magneto-optical effect of optical fiber has many applications in monitoring magnetic field and electric current. When a linearly polarized light propagates in the direction of a magnetic field, the plane of polarization will rotate linearly proportional to the strength of the applied magnetic field, which following the relationship of θF =VBl. θF is the Faraday rotation angle, which is proportional to the magnetic flux density B and the Verdet constant V . However, when the optical fiber contains the effect of linear birefringence, the detection of Faraday rotation angle will depend on the line birefringence. In order to determine the Verdet constant of an optical fiber under a linear birefringence, the fiber birefringence needs to be accurately measured. In this work, a model is applied to analyze the polarization properties of an optical fiber by using the Jones matrix method. A measurement system based on the lock-in amplifier technology is designed to test the Verdet constant and the birefringence of optical fiber. The magnetic field is produced by a solenoid with a DC current. A tunable laser is intensity modulated with a motorized rotating chopper. The actuator supplies a signal as the phase-locked synchronization reference to the signal of the lock-in amplifier. The measurement accuracy is analyzed and the sensitivity of the system is optimized. In this measurement system, the Verdet constant of the SMF-28 fiber was measured to be 0.56±0.02 rad/T·m at 1550nm. This setup is well suitable for measuring the high signal-to-noise ratio (SNR) sensitivity for lock-in amplifier at a low magnetic field strength.

  2. Fiber optical cable and connector system (FOCCoS) for PFS/ Subaru

    Science.gov (United States)

    de Oliveira, Antonio Cesar; de Oliveira, Lígia Souza; de Arruda, Marcio V.; Souza Marrara, Lucas; dos Santos, Leandro H.; Ferreira, Décio; dos Santos, Jesulino B.; Rosa, Josimar A.; Junior, Orlando V.; Pereira, Jeferson M.; Castilho, Bruno; Gneiding, Clemens; Junior, Laerte S.; de Oliveira, Claudia M.; Gunn, James; Ueda, Akitoshi; Takato, Naruhisa; Shimono, Atsushi; Sugai, Hajime; Karoji, Hiroshi; Kimura, Masahiko; Tamura, Naoyuki; Wang, Shiang-Yu; Murray, Graham; Le Mignant, David; Madec, Fabrice; Jaquet, Marc; Vives, Sebastien; Fisher, Charlie; Braun, David; Schwochert, Mark; Reiley, Daniel J.

    2014-07-01

    FOCCoS, "Fiber Optical Cable and Connector System" has the main function of capturing the direct light from the focal plane of Subaru Telescope using optical fibers, each one with a microlens in its tip, and conducting this light through a route containing connectors to a set of four spectrographs. The optical fiber cable is divided in 3 different segments called Cable A, Cable B and Cable C. Multi-fibers connectors assure precise connection among all optical fibers of the segments, providing flexibility for instrument changes. To assure strong and accurate connection, these sets are arranged inside two types of assemblies: the Tower Connector, for connection between Cable C and Cable B; and the Gang Connector, for connection between Cable B and Cable A. Throughput tests were made to evaluate the efficiency of the connections. A lifetime test connection is in progress. Cable C is installed inside the PFI, Prime Focus Instrument, where each fiber tip with a microlens is bonded to the end of the shaft of a 2-stage piezo-electric rotatory motor positioner; this assembly allows each fiber to be placed anywhere within its patrol region, which is 9.5mm diameter.. Each positioner uses a fiber arm to support the ferrule, the microlens, and the optical fiber. 2400 of these assemblies are arranged on a motor bench plate in a hexagonal-closed-packed disposition. All optical fibers from Cable C, protected by tubes, pass through the motors' bench plate, three modular plates and a strain relief box, terminating at the Tower Connector. Cable B is permanently installed at Subaru Telescope structure, as a link between Cable C and Cable A. This cable B starts at the Tower Connector device, placed on a lateral structure of the telescope, and terminates at the Gang Connector device. Cable B will be routed to minimize the compression, torsion and bending caused by the cable weight and telescope motion. In the spectrograph room, Cable A starts at the Gang Connector, crosses a

  3. A controlled release system of titanocene dichloride by electrospun fiber and its antitumor activity in vitro.

    Science.gov (United States)

    Chen, Ping; Wu, Qing-Sheng; Ding, Ya-Ping; Chu, Maoquan; Huang, Zheng-Ming; Hu, Wen

    2010-11-01

    In order to improve both safety and efficacy of cancer chemotherapy of titanocene dichloride and overcome the shortcomings such as instability and short half-life in the human body, we report a controlled release system of titanocene dichloride by electrospun fiber and its in vitro antitumor activity against human lung tumor spca-1 cells. The system was developed by electrospinning. The release profiles of titanocene dichloride in PBS were researched by UV-Vis spectrophotometer. In vitro antitumor activities of the fibers were examined by MTT method. Titanocene dichloride was well incorporated in biodegradable poly(L-lactic acid) fibers. XRD results suggest that titanocene dichloride exists in the amorphous form in the fibers. The controlled release of titanocene dichloride can be gained for long time. MTT showed actual titanocene dichloride content 40, 80, 160 and 240 mg/L from the fibers mat, cell growth inhibition rates of 11.2%, 22.1%, 44.2% and 68.2% were achieved, respectively. The titanocene dichloride released has obvious inhibition effect against lung tumor cells. The system has an effect of controlled release of titanocene dichloride and may be used as an implantable anticancer drug in clinical applications in the future.

  4. Bragg grating-based fiber laser vibration sensing system with novel phase detection

    Science.gov (United States)

    Yang, Xiufeng; Chen, Zhihao; Teo, Ju Teng; Ng, Soon Huat

    2014-01-01

    We characterized the dynamic response of a Bragg grating-based fiber laser sensing system. The sensing system comprises of a narrow line width fiber laser based on π-phase-shifted fiber Bragg grating formed in an active fiber, an unbalanced fiber Michelson interferometer (FMI), which performs wavelength-to-phase mapping, and a phase detection algorithm, which acquires the phase change from the interferometric output signal. The novel phase detection algorithm is developed based on the combination of the two traditional phase generated carrier algorithms: differential-cross-multiplying and arctangent algorithms, and possesses the advantages of the two algorithms. The modulation depth fluctuation of the carrier does not affect the performance of the sensing system. A relatively high side mode suppression ratio of above 50 dB has been achieved within a wide range of carrier amplitude from 1.6 to 5.0 V which correspond to the modulation depth from 1.314 to 4.106 rad. The linearity is 99.082% for the relationship between the power spectral density (dBm/Hz) of the detected signal and the amplitude (mv) of the test signal. The unbalanced FMI is used to eliminate the polarization effect.

  5. Using Brillouin fiber-optic ring laser to provide base station with uplink optical carrier in a 10 GHz radio over fiber system

    Institute of Scientific and Technical Information of China (English)

    CHEN Hao-shuo; LIN Ru-jian; YE Jia-jun

    2009-01-01

    In this paper, a 10 GHz radio over fiber system is analyzed. The Brillouin fiber-optic ring laser is used in the center station (CS) to suppress the optical carrier for the modulation depth enhancement. Simultaneously, the Stockes waveinduced by the Brillouin amplification injects and locks the Fabry-Perot (FP) laser to output a signal-mode optical source,which works as the uplink optical carrier.

  6. Modified optical fiber daylighting system with sunlight transportation in free space.

    Science.gov (United States)

    Vu, Ngoc-Hai; Pham, Thanh-Tuan; Shin, Seoyong

    2016-12-26

    We present the design, optical simulation, and experiment of a modified optical fiber daylighting system (M-OFDS) for indoor lighting. The M-OFDS is comprised of three sub-systems: concentration, collimation, and distribution. The concentration part is formed by coupling a Fresnel lens with a large-core plastic optical fiber. The sunlight collected by the concentration sub-system is propagated in a plastic optical fiber and then collimated by the collimator, which is a combination of a parabolic mirror and a convex lens. The collimated beam of sunlight travels in free space and is guided to the interior by directing flat mirrors, where it is diffused uniformly by a distributor. All parameters of the system are calculated theoretically. Based on the designed system, our simulation results demonstrated a maximum optical efficiency of 71%. The simulation results also showed that sunlight could be delivered to the illumination destination at distance of 30 m. A prototype of the M-OFDS was fabricated, and preliminary experiments were performed outdoors. The simulation results and experimental results confirmed that the M-OFDS was designed effectively. A large-scale system constructed by several M-OFDSs is also proposed. The results showed that the presented optical fiber daylighting system is a strong candidate for an inexpensive and highly efficient application of solar energy in buildings.

  7. An automatic mode-locked system for passively mode-locked fiber laser

    Science.gov (United States)

    Li, Sha; Xu, Jun; Chen, Guoliang; Mei, Li; Yi, Bo

    2013-12-01

    This paper designs and implements one kind of automatic mode-locked system. It can adjust a passively mode-locked fiber laser to keep steady mode-locked states automatically. So the unsteadiness of traditional passively mode-locked fiber laser can be avoided. The system transforms optical signals into electrical pulse signals and sends them into MCU after processing. MCU calculates the frequency of the signals and judges the state of the output based on a quick judgment algorithm. A high-speed comparator is used to check the signals and the comparison voltage can be adjusted to improve the measuring accuracy. Then by controlling two polarization controllers at an angle of 45degrees to each other, MCU extrudes the optical fibers to change the polarization until it gets proper mode-locked output. So the system can continuously monitor the output signal and get it back to mode-locked states quickly and automatically. States of the system can be displayed on the LCD and PC. The parameters of the steady mode-locked states can be stored into an EEPROM so that the system will get into mode-locked states immediately next time. Actual experiments showed that, for a 6.238MHz passively mode-locked fiber lasers, the system can get into steady mode-locked states automatically in less than 90s after starting the system. The expected lock time can be reduced to less than 20s after follow up improvements.

  8. In-Building Wireless Distribution in legacy Multimode Fiber with an improved RoMMF system

    DEFF Research Database (Denmark)

    Visani, Davide; Petersen, Martin Nordal; Sorci, Francesca

    2012-01-01

    A radio over multimode fiber (RoMMF) system for in-building wireless distribution employing a directly modulated Fabry-Perot (FP) transmitter and the central launch technique is presented. The worst-case spurious free dynamic range (SFDR) exceeds 105 dB×Hz2/3 up to 525 m of OM2 multimode fiber (MMF......). Experimental and theoretical results are reported showing that this scheme outperforms a RoMMF system employing a distributed feed-back (DFB) laser diode (LD) and/or a mode scrambler to achieve overfilled launch (OFL). Long Term Evolution (LTE) signal transmission is achieved with high quality in terms...

  9. A compact terahertz burst emission system driven with 1 μm fiber laser

    Science.gov (United States)

    Adamonis, Juozas; Rusteika, Nerijus; Danilevičius, Rokas; Krotkus, Arūnas

    2013-04-01

    In this work we propose a compact, easily tunable terahertz burst generation system based on the mixing of two linearly chirped optical pulses in the Michelson interferometer. The use of linearly chirped optical pulses ejected straight from the fiber laser enabled us to avoid bulky external optical pulse stretching schemes. Even for non-compensated third and higher order dispersion that is taking place in the optical fiber terahertz bursts of relatively narrow bandwidth of 55 GHz were registered. The system operation range determined from the power measurements reached 2 THz.

  10. 123 km Φ-OTDR system based on bidirectional erbium-doped fiber amplifier

    Science.gov (United States)

    Tian, Xiaozhong; Dang, Rui; Tan, Dongjie; Liu, Lu; Wang, Haiming

    2016-10-01

    Based on bidirectional Erbium-doped fiber amplifier (B-EDFA), which can amplify not only forward pulse light but also backward Rayleigh scattering light, a long distance (123 km) Φ-OTDR system is demonstrate. In this system, four B-EDFAs are employed to extend sensing length. Meanwhile, by using the difference value of upper-envelope and lower-envelope of Rayleigh scattering trace, the intrusion with SNR of 5.45 dB, 3.64 dB and 4.51 dB at three test points of sensing fiber is extracted.

  11. A distributed optical fiber sensing system for dynamic strain measurement based on artificial reflector

    Science.gov (United States)

    Sun, Zhenhong; Shan, Yuanyuan; Li, Yanting; Zhang, Yixin; Zhang, Xuping

    2016-10-01

    Phase sensitive optical time domain reflectometry (Φ-OTDR) has been widely used in many applications for its distributed sensing ability on weak disturbance all along the sensing fiber. However, traditional Φ-OTDR cannot make quantitative measurement on the external disturbance due to the randomly distributed position and reflectivity of scatters within the optical fiber. Recently, some methods have been proposed to realize quantitative measurement of dynamic strain. In these literatures, the fiber with or without FBGs in practice was easily damaged and with difficulty of maintenance. PZT is employed to generate strain event in the fiber. There is a large gap compared with the real detecting environment, which will not reveal the full performance of the sensing system. In this paper, a distributed optical fiber sensing (DOFS) system for dynamic strain measurement based on artificial reflector is proposed and demonstrated experimentally. The fiber under test (FUT) is composed by four 20-meter long single mode optical fiber patch cords (OFPCs), which are cascaded with ferrule contactor/physical contact (FC/PC) connectors via fiber flanges. The fiber facet of FC/PC connector forms an artificial reflector. When the interval between the two reflectors is changed, the phase of the interference signal will also be changed. A symmetric 3×3 coupler with table-look-up scheme is introduced to discriminate the phase change through interference intensity. In our experiment, the center 10m section of the second OFPC is attached to the bottom of an aluminum alloy plate. An ordinary loudspeaker box was located on the top of the aluminum alloy plate. The dynamic strain generated by the loudspeaker box is transmitted from the aluminum alloy plate to the OFPC. Experimental results show that the proposed method has a good frequency response characteristic up to 3.2 kHz and a linear intensity response of R2=0.9986 while the optical probe pulse width and repetition rate were 100ns

  12. Communication architecture system for fiber positioning of DESI spectrograph

    Science.gov (United States)

    Kaci, Karim; Glez-de-Rivera, Guillermo; Lopez-Colino, Fernando; Martinez-Garcia, M. Sofia; Masa, Jose L.; Garrido, Javier; Sanchez, Justo; Prada, Francisco

    2016-07-01

    This paper presents a design proposal for controlling the five thousand fiber positioners within the focal plate of the DESI instrument. Each of these positioners is a robot which allows positioning its optic fiber with a resolution within the range of few microns. The high number and density of these robots poses a challenge for handling the communication from a central control device to each of these five thousand. Furthermore, an additional restriction applies as the required time to communicate to every robot of its position must be smaller than a second. Additionally. a low energy consumption profile is also desired. Both wireless and wired communication protocols have been evaluated, proposing single-technology-based architectures and hybrid ones (a combination of them). Among the wireless solutions, ZigBee and CyFi have been considered. Using simulation tools these wireless protocols have been discarded as they do not allow an efficient communication. The studied wired protocols comprise I2C, CAN and Ethernet. The best solution found is a hybrid multilayer architecture combining both Ethernet and I2C. A 100 Mbps Ethernet based network is used to communicate the central control unit with ten management boards. Each of these boards is a low-cost, low-power embedded device that manages a thirty six degrees sector of the sensing plate. Each of these boards receives the positioning data for five hundred robots and communicate with each one through a fast mode plus I2C bus. This proposal allows to communicate the positioning information for all five thousand robots in 350 ms total.

  13. Fiber optic system design for vehicle detection and analysis

    Science.gov (United States)

    Nedoma, Jan; Zboril, Ondrej; Fajkus, Marcel; Zavodny, Petr; Kepak, Stanislav; Bednarek, Lukas; Martinek, Radek; Vasinek, Vladimir

    2016-04-01

    Fiber optic interferometers belong to a group of highly sensitive and precise devices enabling to measure small changes in the deformation shapes, changes in pressure, temperature, vibration and so on. The basis of their activity is to evaluate the number of fringes over time, not changes in the intensity of the optical signal. The methodology described in the article is based on using the interferometer to monitor traffic density. The base of the solution is a Mach-Zehnder interferometer operating with single-mode G.652 optical fiber at the wavelength of 1550 nm excited by a DFB laser. The power distribution of the laser light into the individual arms of the interferometer is in the ratio 1:1. Realized measuring scheme was terminated by an optical receiver including InGaAs PIN photodiode. Registered signal from the photodetector was through 8 Hz high pass filter fed to the measuring card that captures the analog input voltage using an application written in LabView development environment. The interferometer was stored in a waterproof box and placed at the side of the road. Here panned individual transit of cars in his environs. Vertically across the road was placed in contact removable belt simulating a retarder, which was used when passing cars to create sufficient vibration response detecting interferometer. The results demonstrated that the individual vehicles passing around boxing showed characteristic amplitude spectra, which was unique for each object, and had sufficient value signal to noise ratio (SNR). The signal was processed by applications developed for the amplitude-frequency spectrum. Evaluated was the maximum amplitude of the signal and compared to the noise. The results were verified by repeated transit of the different types of cars.

  14. Spectrally Tailored Pulsed Thulium Fiber Laser System for Broadband Lidar CO2 Sensing

    Science.gov (United States)

    Heaps, William S.; Georgieva, Elena M.; McComb, Timothy S.; Cheung, Eric C.; Hassell, Frank R.; Baldauf, Brian K.

    2011-01-01

    Thulium doped pulsed fiber lasers are capable of meeting the spectral, temporal, efficiency, size and weight demands of defense and civil applications for pulsed lasers in the eye-safe spectral regime due to inherent mechanical stability, compact "all-fiber" master oscillator power amplifier (MOPA) architectures, high beam quality and efficiency. Thulium fiber's longer operating wavelength allows use of larger fiber cores without compromising beam quality, increasing potential single aperture pulse energies. Applications of these lasers include eye-safe laser ranging, frequency conversion to longer or shorter wavelengths for IR countermeasures and sensing applications with otherwise tough to achieve wavelengths and detection of atmospheric species including CO2 and water vapor. Performance of a portable thulium fiber laser system developed for CO2 sensing via a broadband lidar technique with an etalon based sensor will be discussed. The fielded laser operates with approximately 280 J pulse energy in 90-150ns pulses over a tunable 110nm spectral range and has a uniquely tailored broadband spectral output allowing the sensing of multiple CO2 lines simultaneously, simplifying future potentially space based CO2 sensing instruments by reducing the number and complexity of lasers required to carry out high precision sensing missions. Power scaling and future "all fiber" system configurations for a number of ranging, sensing, countermeasures and other yet to be defined applications by use of flexible spectral and temporal performance master oscillators will be discussed. The compact, low mass, robust, efficient and readily power scalable nature of "all-fiber" thulium lasers makes them ideal candidates for use in future space based sensing applications.

  15. Discrete fiber-reinforced polyurea systems for infrastructure strengthening and blast mitigation

    Science.gov (United States)

    Carey, Natalia L.

    The research presented in this dissertation focused on evaluating the effectiveness of various blast mitigation materials and coating technologies to be used for enhancing blast resistance of structural members. Mechanical properties and blast mitigation performance of different discrete fiber-reinforced polyurea (DFRP) systems were investigated through experimental and analytical work. Four technical papers discuss the research efforts conducted within this dissertation. The first paper examined the development and characterization of different DFRP systems for infrastructure strengthening and blast retrofit. The behavior of various systems which consisted of chopped E-glass fibers discretely integrated in with the polyurea matrix was evaluated through coupon tensile testing. The addition of glass fiber to a polymer coating provided improved stiffness and strength to the composite system while the polyurea base material provided ductility. The second paper evaluated the behavior of hybrid, plain, and steel fiber-reinforced concrete panels coated with various polyurea and DFRP systems under blast loading. Hybrid panels demonstrated higher blast mitigation performance compared to plain and steel fiber-reinforced concrete panels due to sacrificial hybrid layer. The addition of plain polyurea or DFRP systems on the tension side improved panel performance by containing fragmentation during a blast event. The third paper presents an analytical investigation conducted using the explicit finite element program LS-DYNA to model panel and coating response under blast loading. Several modeling solutions were undertaken and compared for concrete formulation. Modeling results were analyzed and compared to the experimental work to validate the conclusions. The final paper describes an internal equilibrium mechanics based model developed to predict the flexural capacity of reinforced concrete beams strengthened with various DFRP systems. The developed model was validated using

  16. Phase shift spectra of a fiber-microsphere system at the single photon level

    CERN Document Server

    Tanaka, Akira; Toubaru, Kiyota; Takashima, Hideaki; Fujiwara, Masazumi; Okamoto, Ryo; Takeuchi, Shigeki; 10.1364/OE.19.002278

    2011-01-01

    We succeeded in measuring phase shift spectra of a microsphere cavity coupled with a tapered fiber using a weak coherent probe light at the single photon level. We utilized a tapered fiber with almost no depolarization and constructed a very stable phase shift measurement scheme based on polarization analysis using photon counting. Using a very weak probe light (\\bar{n} = 0:41), we succeeded in observing the transition in the phase shift spectrum between undercoupling and overcoupling (at gap distances of 500 and 100 nm, respectively).We also used quantum state tomography to obtain a 'purity spectrum'. Even in the overcoupling regime, the average purity was 0.982 \\pm 0.024 (minimum purity: 0.892), suggesting that the coherence of the fiber-microsphere system was well preserved. Based on these results, we believe this system is applicable to quantum phase gates using single light emitters such as diamond nitrogen vacancy centers.

  17. Advances in fibers and transmission line technology for long haul submarine systems

    Science.gov (United States)

    Peckham, David W.; Kim, Jinkee; Sun, Yi; Lingle, Robert L., Jr.; Levring, Ole

    2007-11-01

    The 7.1-magnitude earthquake on December 26, 2006 in the Strait of Luzon resulted in the failure of several submarine cable systems. Seven of the nine cables that pass through the strait were damaged, disrupting communications to China, Taiwan, Japan, Korea and Singapore. This recent event highlighted the dependence of international communications on submarine fiber optic transmission systems. This paper will review the evolution of optical fiber transmission line technology that has been deployed in the long haul undersea telecommunications network. It will start with a discussion of the chronological evolution of the optical fiber transmission line architecture in section one, then give more detail regarding the technology that is still being deployed today.

  18. Photonic liquid crystal fibers tuning by four electrode system produced with 3D printing technology

    Science.gov (United States)

    Ertman, Slawomir; Bednarska, Karolina; Czapla, Aleksandra; Woliński, Tomasz R.

    2015-09-01

    Photonic liquid crystal fiber has been intensively investigated in last few years. It has been proved that guiding properties of such fibers could be tuned with an electric field. In particular efficient tuning could be obtained if multi-electrode system allowing for dynamic change of not only intensity of the electric field, but also its direction. In this work we report a simple to build four electrode system, which is based on a precisely aligned four cylindrical microelectrodes. As an electrodes we use enameled copper wire with diameter adequate to the diameter of the fiber to be tuned. To ensure uniform and parallel alignment of the wires a special micro-profiles has been designed and then produced with filament 3D printer. The possibility of the dynamic change of the electric field direction in such scalable and cost effective electrode assembly has been experimentally confirmed.

  19. Functionality Enhancement of Industrialized Optical Fiber Sensors and System Developed for Full-Scale Pavement Monitoring

    Directory of Open Access Journals (Sweden)

    Huaping Wang

    2014-05-01

    Full Text Available Pavements always play a predominant role in transportation. Health monitoring of pavements is becoming more and more significant, as frequently suffering from cracks, rutting, and slippage renders them prematurely out of service. Effective and reliable sensing elements are thus in high demand to make prognosis on the mechanical properties and occurrence of damage to pavements. Therefore, in this paper, various types of functionality enhancement of industrialized optical fiber sensors for pavement monitoring are developed, with the corresponding operational principles clarified in theory and the performance double checked by basic experiments. Furthermore, a self-healing optical fiber sensing network system is adopted to accomplish full-scale monitoring of pavements. The application of optical fiber sensors assembly and self-healing network system in pavement has been carried out to validate the feasibility. It has been proved that the research in this article provides a valuable method and meaningful guidance for the integrity monitoring of civil structures, especially pavements.

  20. Survival and relaxation time, pore size distribution moments, and viscous permeability in random unidirectional fiber structures

    Science.gov (United States)

    Tomadakis, Manolis M.; Robertson, Teri J.

    2005-03-01

    Computer simulation results are presented for the mean survival time, principal relaxation time, mean pore size, and mean square pore size, for random porous structures consisting of parallel nonoverlapping or partially overlapping fibers. The numerical procedure is based on a discrete step-by-step random walk mechanism simulating the Brownian diffusion trajectories of molecules in the porous media. Numerical results on the viscous permeability of these structures are computed with a method based on electrical conduction principles and compared to a variational bound derived from the mean survival time. The results show that nonoverlapping fiber structures exhibit lower values of the dimensionless mean survival time, principal relaxation time, mean pore size, and mean square pore size than randomly overlapping fiber structures of the same porosity, while partially overlapping fiber structures show behavior intermediate to those of the two extreme cases. The mean square pore size (second moment of the pore size distribution) is found to be a very good predictor of the mean survival time for non-, partially, and randomly overlapping fiber structures. Dimensionless groups representing the deviation of variational bounds from our simulation results vary in practically the same range as the corresponding values reported earlier for beds of spherical particles. A universal scaling expression of the literature relating the mean survival time to structural properties [S. Torquato and C. L. Y. Yeong, J. Chem. Phys. 106, 8814 (1997)] agrees very well with our results for all examined fiber structures, thus validated for the first time for porous media formed by partially overlapping particles. The permeability behavior of partially overlapping fiber structures resembles that of nonoverlapping fiber structures for flow parallel to the fibers, but not for transverse flow, where percolation phenomena prevail. The permeability results for beds of unidirectional partially

  1. Fiber faceplate modulation readout in Bi-material micro-cantilever mirror array imaging system

    Science.gov (United States)

    Hui, Mei; Xia, Zhengzheng; Liu, Ming; Dong, Liquan; Liu, Xiaohua; Zhao, Yuejin

    2016-05-01

    Fiber faceplate modulation was applied to read out the precise actuation of silicon-based, surface micro-fabricated cantilever mirrors array in optical imaging system. The faceplate was made by ordered bundles consisting of as many as ten thousands fibers. The transmission loss of an individual fiber in the bundles was 0.35dB/cm and the cross talk between neighboring fibers in the faceplate was about 15%. Micro-cantilever mirrors array (Focal-Plane Array (FPA)) which composed of two-level bi-material pixels, absorb incident infrared flux and result in a temperature increase. The temperature distribution of incident flux transformed to the deformation distribution in FPA which has a very big difference in coefficients of thermal expansion. FPA plays the roles of target sensing and has the characteristics of high detection sensitivity. Instead of general filter such as knife edge or pinhole, fiber faceplate modulate the beam reflected by the units of FPA. An optical readout signal brings a visible spectrum into pattern recognition system, yielding a visible image on monitor. Thermal images at room temperature have been obtained. The proposed method permits optical axis compact and image noise suppression.

  2. Apatite coating of electrospun PLGA fibers using a PVA vehicle system carrying calcium ions.

    Science.gov (United States)

    Kim, In Ae; Rhee, Sang-Hoon

    2010-01-01

    A novel method to coat electrospun poly(D,L-lactic-co-glycolic acid) (PLGA) fiber surfaces evenly and efficiently with low-crystalline carbonate apatite crystals using a poly(vinyl alcohol) (PVA) vehicle system carrying calcium ions was presented. A non-woven PLGA fabric was prepared by electrospinning: a 10 wt% PLGA solution was prepared using 1,1,3,3-hexafluoro-2-propanol as a solvent and electrospun under a electrical field of 1 kV/cm using a syringe pump with a flowing rate of 3 ml/h. The non-woven PLGA fabric, 12 mm in diameter and 1 mm in thickness, was cut and then coated with a PVA solution containing calcium chloride dihydrate (specimen PPC). As controls, pure non-woven PLGA fabric (specimen P) and fabric coated with a calcium chloride dihydrate solution without PVA (specimen PC) were also prepared. Three specimens were exposed to simulated body fluid for 1 week and this exposure led to form uniform and complete apatite coating layer on the fiber surfaces of specimen PPC. However, no apatite had formed to the fiber surfaces of specimen P and only inhomogeneous coating occurred on the fiber surfaces of specimen PC. These results were explained in terms of the calcium chelating and adhesive properties of PVA vehicle system. The practical implication of the results is that this method provides a simple but efficient technique for coating the fiber surface of an initially non-bioactive material with low-crystalline carbonate apatite.

  3. 64-GHz millimeter-wave photonic generation with a feasible radio over fiber system

    Science.gov (United States)

    Al-Dabbagh, Rasha K.; Al-Raweshidy, Hamed S.

    2017-02-01

    A full-duplex radio over fiber (RoF) link with the generation of a 64-GHz millimeter wave (mm-wave) is investigated. This system is proposed as a solution to cope with the demands of a multi-Gb/s data transmission in the fifth generation (5G) and beyond for small cell networks. Cost reduction and performance improvement are achieved by simplifying the mm-wave generation method with an RoF technique. High-frequency radio signals are considered challenging in the electrical generation domain; therefore, our photonic generation method is introduced and examined. RoF design is proposed for mm-wave generation using both phase modulation and the effect of stimulated Brillouin scattering in the optical fiber for the first time. RoF system with transmission rates of 5 Gb/s is successfully achieved. In our scheme, one laser source is utilized and a fiber Bragg grating is used for wavelength reuse for the uplink connection. Stable mm-wave RoF link is successfully achieved in up to a 100-km fiber link length with high quality carrier. Simulation results show a reduction in fiber nonlinearity effects and the mm-wave signal has low noise equal to -75 dBm. This study ensures a practical mm-wave RoF link, and it could be appropriate for small cell 5G networks by reducing the installation cost.

  4. Development of a flexible optical fiber based high resolution integrated PET∕MRI system.

    Science.gov (United States)

    Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Watabe, Tadashi; Aoki, Masaaki; Sugiyama, Eiji; Kato, Katsuhiko; Hatazawa, Jun

    2012-11-01

    The simultaneous measurement of PET and magnetic resonance imaging (MRI) is an emerging field for molecular imaging research. Although optical fiber based PET∕MRI systems have advantages on less interference between PET and MRI, there is a drawback in reducing the scintillation light due to the fiber. To reduce the problem, the authors newly developed flexible optical fiber bundle based block detectors and employed them for a high resolution integrated PET∕MRI system. The flexible optical fiber bundle used 0.5 mm diameter, 80 cm long double clad fibers which have dual 12 mm × 24 mm rectangular inputs and a single 24 mm × 24 mm rectangular output. In the input surface, LGSO scintillators of 0.025 mol.% (decay time: ∼31 ns: 0.9 mm × 1.3 mm × 5 mm) and 0.75 mol.% (decay time: ∼46 ns: 0.9 mm × 1.3 mm × 6 mm) were optically coupled in depth direction to form depth-of-interaction detector, arranged in 11 × 13 matrix and optically coupled to the fiber bundle. The two inputs of the bundle are bent for 90°, bound to one, and are optically coupled to a Hamamatsu 1-in. square position sensitive photomultiplier tube. Light loss due to the fiber bundle could be reduced and the performance of the block detectors was improved. Eight optical fiber based block detectors (16 LGSO blocks) were arranged in a 56 mm diameter ring to form a PET system. Spatial resolution and sensitivity were 1.2 mm full-width at half-maximum and 1.2% at the central field-of-view, respectively. Sensitivity change was less than 1% for 2 °C temperature changes. This PET system was integrated with a 0.3 T permanent magnet MRI system which has 17 cm diameter hole at the yoke area for insertion of the PET detector ring. There was no observable interference between PET and MRI. Simultaneous imaging of PET and MRI was successfully performed for small animal studies. The authors confirmed that the developed high resolution PET∕MRI system is promising for molecular

  5. Fiber optic Cerenkov radiation sensor system to estimate burn-up of spent fuel: characteristic evaluation of the system using Co-60 source

    Science.gov (United States)

    Shin, S. H.; Jang, K. W.; Jeon, D.; Hong, S.; Kim, S. G.; Sim, H. I.; Yoo, W. J.; Park, B. G.; Lee, B.

    2013-09-01

    Cerenkov radiation occurs when charged particles are moving faster than the speed of light in a transparent dielectric medium. In optical fibers, the Cerenkov light also can be generated due to their dielectric components. Accordingly, the radiation-induced light signals can be obtained using optical fibers without any scintillating material. In this study, to measure the intensities of Cerenkov radiation induced by gamma-rays, we have fabricated the fiber-optic Cerenkov radiation sensor system using silica optical fibers, plastic optical fibers, multi-anode photomultiplier tubes, and a scanning system. To characterize the Cerenkov radiation generated in optical fibers, the spectra of Cerenkov radiation generated in the silica and plastic optical fibers were measured. Also, the intensities of Cerenkov radiation induced by gamma-rays generated from a cylindrical Co-60 source with or without lead shielding were measured using the fiberoptic Cerenkov radiation sensor system.

  6. Elimination of drift in a fiber-Bragg-grating-based multiplexed Michelson interferometer measurement system.

    Science.gov (United States)

    Ren, Junyu; Xie, Fang; Chen, Zhimin

    2010-02-01

    Random phase drift in single-mode optical fiber interferometers used with measurement systems, which is resulted from various types of environmental disturbances, should be eliminated in order to obtain high measurement precision. We propose an optical fiber interferometric measurement system which has the function of self-eliminating the random phase drift and is stable and robust enough for real-time precision measurement. By employing the characteristics of fiber Bragg gratings, the system interleaves two fiber Michelson interferometers together that share the common-interferometric-optical path. The signal of one of the interferometers is used to stabilize the system while the signal of the other interferometer is used for measurement. An electronic feedback loop for the stabilizing action is designed. The bandwidth of the feedback loop is 5 kHz, sufficiently wide to eliminate random phase drift resulted from various environmental disturbances. The system is endowed with high stability and therefore suitable for real-time precision measurement. By means of an active phase tracking technique to measure displacement, the linear regression coefficient of the displacement measurement results is 0.9998.

  7. Elimination of drift in a fiber-Bragg-grating-based multiplexed Michelson interferometer measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Ren Junyu; Xie Fang; Chen Zhimin [Department of Physics, School of Science, Beijing Jiaotong University, Beijing 100044 (China)

    2010-02-15

    Random phase drift in single-mode optical fiber interferometers used with measurement systems, which is resulted from various types of environmental disturbances, should be eliminated in order to obtain high measurement precision. We propose an optical fiber interferometric measurement system which has the function of self-eliminating the random phase drift and is stable and robust enough for real-time precision measurement. By employing the characteristics of fiber Bragg gratings, the system interleaves two fiber Michelson interferometers together that share the common-interferometric-optical path. The signal of one of the interferometers is used to stabilize the system while the signal of the other interferometer is used for measurement. An electronic feedback loop for the stabilizing action is designed. The bandwidth of the feedback loop is 5 kHz, sufficiently wide to eliminate random phase drift resulted from various environmental disturbances. The system is endowed with high stability and therefore suitable for real-time precision measurement. By means of an active phase tracking technique to measure displacement, the linear regression coefficient of the displacement measurement results is 0.9998.

  8. Elimination of drift in a fiber-Bragg-grating-based multiplexed Michelson interferometer measurement system

    Science.gov (United States)

    Ren, Junyu; Xie, Fang; Chen, Zhimin

    2010-02-01

    Random phase drift in single-mode optical fiber interferometers used with measurement systems, which is resulted from various types of environmental disturbances, should be eliminated in order to obtain high measurement precision. We propose an optical fiber interferometric measurement system which has the function of self-eliminating the random phase drift and is stable and robust enough for real-time precision measurement. By employing the characteristics of fiber Bragg gratings, the system interleaves two fiber Michelson interferometers together that share the common-interferometric-optical path. The signal of one of the interferometers is used to stabilize the system while the signal of the other interferometer is used for measurement. An electronic feedback loop for the stabilizing action is designed. The bandwidth of the feedback loop is 5 kHz, sufficiently wide to eliminate random phase drift resulted from various environmental disturbances. The system is endowed with high stability and therefore suitable for real-time precision measurement. By means of an active phase tracking technique to measure displacement, the linear regression coefficient of the displacement measurement results is 0.9998.

  9. FOREX-A Fiber Optics Diagnostic System For Study Of Materials At High Temperatures And Pressures

    Science.gov (United States)

    Smith, D. E.; Roeske, F.

    1983-03-01

    We have successfully fielded a Fiber Optics Radiation EXperiment system (FOREX) designed for measuring material properties at high temperatures and pressures on an underground nuclear test. The system collects light from radiating materials and transmits it through several hundred meters of optical fibers to a recording station consisting of a streak camera with film readout. The use of fiber optics provides a faster time response than can presently be obtained with equalized coaxial cables over comparable distances. Fibers also have significant cost and physical size advantages over coax cables. The streak camera achieves a much higher information density than an equivalent oscilloscope system, and it also serves as the light detector. The result is a wide bandwidth high capacity system that can be fielded at a relatively low cost in manpower, space, and materials. For this experiment, the streak camera had a 120 ns time window with a 1.2 ns time resolution. Dynamic range for the system was about 1000. Beam current statistical limitations were approximately 8% for a 0.3 ns wide data point at one decade above the threshold recording intensity.

  10. A Pilot-Scale System for Carbon Molecular Sieve Hollow Fiber Membrane Manufacturing

    KAUST Repository

    Karvan, O.

    2012-12-21

    Carbon molecular sieve (CMS) membranes offer advantages over traditional polymeric membrane materials, but scale-up of manufacturing systems has not received much attention. In the recent decade, there has been a dramatic increase in fundamental research on these materials with a variety of applications being studied. The results from a pilot-scale CMS production system are presented. This system was designed based on extensive laboratory research, and hollow fiber membranes produced in this system show similar performance compared to membranes produced using a smaller bench-scale system. After optimizing the system design, a 93% recovery of the precursor fibers for use in membrane module preparation were obtained. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Multigigabit W-Band (75–110 GHz) Bidirectional Hybrid Fiber-Wireless Systems in Access Networks

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Lebedev, Alexander; Vegas Olmos, Juan José

    2014-01-01

    We experimentally demonstrate multigigabit capacity bidirectional hybrid fiber-wireless systems with RF carrier frequencies at the W-band (75-110 GHz) that enables the seamless convergence between wireless and fiber-optic data transmission systems in access networks. In this study, we evaluate...

  12. Fusion of a FBG-based health monitoring system for wind turbines with a fiber-optic lightning detection system

    Science.gov (United States)

    Krämer, Sebastian G. M.; Wiesent, Benjamin; Müller, Mathias S.; Puente León, Fernando; Méndez Hernández, Yarú

    2008-04-01

    Wind turbine blades are made of composite materials and reach a length of more than 42 meters. Developments for modern offshore turbines are working on about 60 meters long blades. Hence, with the increasing height of the turbines and the remote locations of the structures, health monitoring systems are becoming more and more important. Therefore, fiber-optic sensor systems are well-suited, as they are lightweight, immune against electromagnetic interference (EMI), and as they can be multiplexed. Based on two separately existing concepts for strain measurements and lightning detection on wind turbines, a fused system is presented. The strain measurement system is based on a reflective fiber-Bragg-grating (FBG) network embedded in the composite structure of the blade. For lightning detection, transmissive &fiber-optic magnetic field sensors based on the Faraday effect are used to register the lightning parameters and estimate the impact point. Hence, an existing lightning detection system will be augmented, due to the fusion, by the capability to measure strain, temperature and vibration. Load, strain, temperature and impact detection information can be incorporated into the turbine's monitoring or SCADA system and remote controlled by operators. Data analysis techniques allow dynamic maintenance scheduling to become a reality, what is of special interest for the cost-effective maintenance of large offshore or badly attainable onshore wind parks. To prove the feasibility of this sensor fusion on one optical fiber, interferences between both sensor systems are investigated and evaluated.

  13. Structural monitoring system with fiber Bragg grating sensors: Implementation and software solution

    CERN Document Server

    Fedorov, Aleksey; Makhrov, Ilya; Pozhar, Nikolay; Anufriev, Maxim; Pnev, Alexey; Karasik, Valeriy

    2014-01-01

    We present a structural health monitoring system for nondestructive testing of composite materials based on the fiber Bragg grating sensors and specialized software solution. Developed structural monitoring system has potential applications for preliminary tests of novel composite materials as well as real-time structural health monitoring of industrial objects. The software solution realizes control for the system, data processing and alert of an operator.

  14. Link Design Rules for Cost-Effective Short-Range Radio Over Multimode Fiber Systems

    DEFF Research Database (Denmark)

    Visani, Davide; Tartarini, Giovanni; Petersen, Martin Nordal

    2010-01-01

    Referring to short-range radio over multimode fiber links, we find out important guidelines for the realization of cost-effective intensity modulated directly detected systems. Since the quality of today's connectors is considerably higher than in the past, we demonstrate that two important param...

  15. An Iterative Method for the Approximation of Fibers in Slow-Fast Systems

    DEFF Research Database (Denmark)

    Kristiansen, Kristian Uldall; Brøns, Morten; Starke, Jens

    2014-01-01

    . The method is demonstrated on the Michaelis--Menten--Henri model and the Lindemann mechanism. The latter example also serves to demonstrate the method on a slow-fast system in nonstandard slow-fast form. Finally, we extend the method further so that it also approximates the curvature of the fibers....

  16. Humidity control during bell pepper storage, using a hollow fiber membrane contractor system

    NARCIS (Netherlands)

    Dijkink, B.H.; Tomassen, M.M.M.; Willemsen, J.H.A.; Doorn, van W.G.

    2004-01-01

    Green bell peppers (Capsicum annuum cv. Cardio) were stored in open crates at 5 degreesC, using a novel system for maintenance of relative humidity (RH). A hollow fiber membrane contactor allowed adequate transfer of water vapor between the air in the storage room and a liquid desiccant. The membran

  17. Synthesis of silver nanoparticles in textile finish aqueous system and their antimicrobial properties on cotton fibers

    Science.gov (United States)

    Silver nanoparticles (NPs) were synthesized by a simple and environmentally benign procedure using poly (ethylene glycol) (PEG) as reducing agent and stabilizer in the textile finish aqueous system, and their antimicrobial properties on greige (mechanically cleaned) and bleached cotton fibers were i...

  18. A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

    Institute of Scientific and Technical Information of China (English)

    Yun-Jiang Rao; Jian Jiang; Zheng-Lin Ran

    2003-01-01

    A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3~4 orders of magnitude in signal level can be achieved.

  19. Humidity control during bell pepper storage, using a hollow fiber membrane contractor system

    NARCIS (Netherlands)

    Dijkink, B.H.; Tomassen, M.M.M.; Willemsen, J.H.A.; Doorn, van W.G.

    2004-01-01

    Green bell peppers (Capsicum annuum cv. Cardio) were stored in open crates at 5 degreesC, using a novel system for maintenance of relative humidity (RH). A hollow fiber membrane contactor allowed adequate transfer of water vapor between the air in the storage room and a liquid desiccant. The membran

  20. A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3~4 orders of magnitude in signal level can be achieved.

  1. Using Distributed Fiber-Optic Sensing Systems to Estimate Inflow and Reservoir Properties

    NARCIS (Netherlands)

    Farshbaf Zinati, F.

    2014-01-01

    Recent developments in the deployment of distributed fiber-optic sensing systems in horizontal wells carry the promise to lead to a new, cheap and reliable way of monitoring production and reservoir performance. Practical applicability of distributed pressure sensing for quantitative inflow detectio

  2. High-speed structural monitoring using a Fiber Bragg Grating sensor system

    NARCIS (Netherlands)

    Cheng, L.K.; Oostdijck, B.W.

    2002-01-01

    We have developed a new interrogation/demultiplexing system for Fiber Bragg Grating (FBG) sensor array. Our approach combines a high readout frequency for all the FBG sensor channels with absolute measurement. This combination is in particular of interest for the detection of dynamic loading, which

  3. A full-duplex radio-over-fiber system with differential phase-shift keying signals

    Energy Technology Data Exchange (ETDEWEB)

    He Jing; Yang Dong; Chen Lin, E-mail: hnu_jhe@hotmail.com [School of Computer and Communication, Hunan University, Changsha 410082 (China)

    2011-02-01

    We propose a full-duplex radio-over-fiber (ROF) system transmitting 2.5 Gb/s differential phase-shift keying (DPSK) signals with 40GHz optical millimeter-wave as downlink. Meanwhile it can be reused central wavelength as uplink connection for transmitting 2.5 Gb/s on-off keying (OOK) signals. The experimental and simulation results show that the downstream 2.5Gb/s DPSK data and the upstream 2.5Gb/s OOK data can transmit 40km single-mode fiber successfully.

  4. Performance Evaluation for DFB and VCSEL-based 60 GHz Radio-over-Fiber System

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Lebedev, Alexander; Vegas Olmos, Juan José

    2013-01-01

    In this paper, we report on a detailed analysis and performance comparison work between 60 GHz radio-over-fiber systems based on a DFB laser and a C-band VCSEL. Coherent photonic up-conversion method is applied for the 60 GHz millimeter-wave signal generation. The generated signals are evaluated...... by means of phase noise and bit error rate for different transmission scenarios. The results show a positive potential to adopt both DFB lasers and VCSELs for the next generation 60 GHz hybrid fiber-wireless access networks....

  5. Impact of Spectral Filter on Phase Modulation Pulse in Fiber Front End System

    Institute of Scientific and Technical Information of China (English)

    LI Jing; JING Feng; WANG Jian-Jun; XU Dang-Peng; LIN Hong-Huan; GENG Yuan-Chao; LI Ming-Zhong; DENG Ying; ZHU Na; ZHANG Rui

    2011-01-01

    The transmission characteristics of phase modulation pulse transmitted through the filter in the power amplifier are investigated theoretically and experimentally. The narrow bandpass filter can induce large temporal modula-tion depth for the phase modulation pulse and induce double amplitude modulation(AM)if the frequency shift is lower than half bandwidth of the signal spectrum. We should choose a wider bandwidth filter to minimize the impact of the filter on the output pulse and suppress the amplified spontaneous emission(ASE) for the power fiber amplifier. These results are of benefit to the design of the fiber front end system.

  6. Fire Source Localization Based on Distributed Temperature Sensing by a Dual-Line Optical Fiber System.

    Science.gov (United States)

    Sun, Miao; Tang, Yuquan; Yang, Shuang; Li, Jun; Sigrist, Markus W; Dong, Fengzhong

    2016-06-06

    We propose a method for localizing a fire source using an optical fiber distributed temperature sensor system. A section of two parallel optical fibers employed as the sensing element is installed near the ceiling of a closed room in which the fire source is located. By measuring the temperature of hot air flows, the problem of three-dimensional fire source localization is transformed to two dimensions. The method of the source location is verified with experiments using burning alcohol as fire source, and it is demonstrated that the method represents a robust and reliable technique for localizing a fire source also for long sensing ranges.

  7. The evaluation of the carbon fiber post system on restoration of teeth defect in children

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiang-hao; WANG Xin-zhi

    2006-01-01

    Background Post and post-core systems are used to restore extensively damaged teeth. Among these systems,cast alloy post and core, prefabricated threaded alloy post and prefabricated simple alloy post are most frequently applied in China nowadays. In Europe and North America a combined application of the fiber post, resin-core and crown has been applied to restore seriously destructed teeth with satisfactory results in recent years. This study was intended to evaluate the clinical effect of carbon fiber post system on restoration of child anterior tooth defect after root canal therapy, based on 3- 5 years' observation.Methods One hundred and six children with incompletely established occlusion were observed and followed for an average of 42 months (ranging from 36 to 60 months). Eighty-five upper teeth and forty-one lower teeth were restored with carbon fiber post system and composite jacket crown. Periodic check-up was conducted for periodontal condition and restoration effect.Results One hundred and twenty-one (96.2%) restorations were successful. Four jacket crowns (3.0%) were lost. One tooth (0.8%) had slight gingival inflammation. Tooth root or post fracture and gingival stain were not observed. X-ray showed there was no obvious change in aspects including the width of periodontal membrane,the density of alveolar bone and the height of alveolar ridge crest.Conclusions Carbon-fiber post system can satisfy the clinical requirements of young patients who have residual anterior crown and root caused by trauma or caries, and have incomplete occlusion and have completed root canal therapy. This system helps realize good esthetic result for patients and easy practice for dentists.Carbon fiber post is safe and convenient, especially for sick children.

  8. Microelectromechanical system pressure sensor integrated onto optical fiber by anodic bonding.

    Science.gov (United States)

    Saran, Anish; Abeysinghe, Don C; Boyd, Joseph T

    2006-03-10

    Optical microelectromechanical system pressure sensors based on the principle of Fabry-Perot interferometry have been developed and fabricated using the technique of silicon-to-silicon anodic bonding. The pressure sensor is then integrated onto an optical fiber by a novel technique of anodic bonding without use of any adhesives. In this anodic bonding technique we use ultrathin silicon of thickness 10 microm to bond the optical fiber to the sensor head. The ultrathin silicon plays the role of a stress-reducing layer, which helps the bonding of an optical fiber to silicon having conventional wafer thickness. The pressure-sensing membrane is formed by 8 microm thick ultrathin silicon acting as a membrane, thus eliminating the need for bulk silicon etching. The pressure sensor integrated onto an optical fiber is tested for static response, and experimental results indicate degradation in the fringe visibility of the Fabry-Perot interferometer. This effect was mainly due to divergent light rays from the fiber degrading the fringe visibility. This effect is demonstrated in brief by an analytical model.

  9. Overlapping and non-overlapping brain regions for theory of mind and self reflection in individual subjects.

    Science.gov (United States)

    Saxe, Rebecca; Moran, Joseph M; Scholz, Jonathan; Gabrieli, John

    2006-12-01

    When subjects are required to reason about someone's false belief, a consistent pattern of brain regions are recruited including the medial prefrontal cortex, medial precuneus and bilateral temporo-parietal junction. Previous group analyses suggest that the two medial regions, but not the lateral regions, are also recruited when subjects engage in self-reflection. The current study directly compared the results of the 'false belief' and 'self' tasks in individual subjects. Consistent with previous reports, the medial prefrontal and medial precuneus regions recruited by the two tasks significantly overlap in individual subjects, although there was also evidence for non-overlapping voxels in medial regions. The temporo-parietal regions are only recruited for the 'theory of mind' task. Six possible models of the relationship between theory of mind, self-reflection and autobiographical memory, all consistent with both neurobiological and developmental evidence to date, are discussed.

  10. Novel design of hollow-core multi clad fiber for long haul optical communication system

    Science.gov (United States)

    Palodiya, Vikram; Raghuwanshi, Sanjeev K.

    2016-09-01

    We have described a dispersion characteristics of hollow-core multi-clad index profiles, which include a hollow core. The designs satisfy the most important requirements for applications in long haul communication. This design fiber shows zero dispersion at 1550 nm can be obtained for the fundamental air core mode over a wide wavelength range by introducing the partial reflector layer around the core, optimizing expanded core size and silica cladding thickness. Also analyze dispersion compensating properties of these fibers. This unique structure of the fundamental air core mode is presented by the introduction of partial reflector cladding around the core. The potential applications of hollow-core multi clad fibers in long-haul optical communication system.

  11. System optimization of a long-range Brillouin-loss-based distributed fiber sensor.

    Science.gov (United States)

    Dong, Yongkang; Chen, Liang; Bao, Xiaoyi

    2010-09-20

    We report a high-performance 25 km Brillouin-loss-based distributed fiber sensor through optimizing system parameters. First, the Brillouin spectrum distortion and measurement error induced by the excess amplification on probe pulse are investigated, and the results indicate that a low continuous-wave pump power is essential to decrease the measurement error. Then an optimal pulse pair is determined through the differential Brillouin gain evolution along the entire sensing fiber in a differential pulse-width pair Brillouin optical time domain analysis. Using dispersion-shifted fiber to allow a high-power probe pulse, we realize a 25 km sensing range with a spatial resolution of 30 cm and a strain accuracy of ±20 με, which we believe is the best performance in such a length, to the best of our knowledge.

  12. Fiber optic system for deflection and damage detection in morphing wing structures

    Science.gov (United States)

    Scheerer, M.; Djinovic, Z.; Schüller, M.

    2013-04-01

    Within the EC Clean Sky - Smart Fixed Wing Aircraft initiative concepts for actuating morphing wing structures are under development. In order for developing a complete integrated system including the actuation, the structure to be actuated and the closed loop control unit a hybrid deflection and damage monitoring system is required. The aim of the project "FOS3D" is to develop and validate a fiber optic sensing system based on low-coherence interferometry for simultaneous deflection and damage monitoring. The proposed system uses several distributed and multiplexed fiber optic Michelson interferometers to monitor the strain distribution over the actuated part. In addition the same sensor principle will be used to acquire and locate the acoustic emission signals originated from the onset and growth of defects like impact damages, cracks and delamination's. Within this paper the authors present the concept, analyses and first experimental results of the mentioned system.

  13. VARIANCE OF NONLINEAR PHASE NOISE IN FIBER-OPTIC SYSTEM

    OpenAIRE

    RANJU KANWAR; SAMEKSHA BHASKAR

    2013-01-01

    In communication system, the noise process must be known, in order to compute the system performance. The nonlinear effects act as strong perturbation in long- haul system. This perturbation effects the signal, when interact with amplitude noise, and results in random motion of the phase of the signal. Based on the perturbation theory, the variance of nonlinear phase noise contaminated by both self- and cross-phase modulation, is derived analytically for phase-shift- keying system. Through th...

  14. Industrial grade fiber-coupled laser systems delivering ultrashort high-power pulses for micromachining

    Science.gov (United States)

    Pricking, Sebastian; Welp, Petra; Overbuschmann, Johannes; Nutsch, Sebastian; Gebs, Raphael; Fleischhaker, Robert; Kleinbauer, Jochen; Wolf, Martin; Budnicki, Aleksander; Sutter, Dirk H.; Killi, Alexander; Mielke, Michael

    2016-03-01

    We report on an industrial fiber-delivered laser system producing ultra-short pulses in the range of a few picoseconds down to a few hundred femtoseconds with high average power suitable for high-precision micromachining. The delivery fiber is a hollow-core photonic crystal fiber with a Kagomé shaped lattice and a hypocycloid core wall enabling the guiding of laser radiation over several meters with exceptionally low losses and preservation of high beam quality (M2laser head providing a compact footprint without the need for external boxes. The laser head is carefully designed regarding its thermo-mechanical properties to allow a highly reliable coupling stability. The exchangeable delivery fiber is packaged using Trumpf's well established LLK-D connectors which offer a very high mechanical precision, the possibility to add water cooling, as well as full featured safety functions. The fiber is hermetically sealed and protected by a robust but flexible shield providing bend protection and break detection. We show the linear and nonlinear optical properties of the transported laser radiation and discuss its feasibility for pulse compression. Measurements are supported by simulation of pulse propagation by solving the nonlinear Schrödinger equation implementing the split-step Fourier method. In addition, mode properties are measured and confirmed by finite element method simulations. The presented industrial laser system offers the known advantages of ultra-short pulses combined with the flexibility of fiber delivery yielding a versatile tool perfectly suitable for all kinds of industrial micromachining applications.

  15. Tissue engineering intrafusal fibers: dose- and time-dependent differentiation of nuclear bag fibers in a defined in vitro system using neuregulin 1-beta-1.

    Science.gov (United States)

    Rumsey, John W; Das, Mainak; Kang, Jung-Fong; Wagner, Robert; Molnar, Peter; Hickman, James J

    2008-03-01

    While much is known about muscle spindle structure, innervation and function, relatively few factors have been identified that regulate intrafusal fiber differentiation and spindle development. Identification of these factors will be a crucial step in tissue engineering functional muscle systems. In this study, we investigated the role of the growth factor, neuregulin 1-beta-1 (Nrg 1-beta-1) EGF, for its ability to influence myotube fate specification in a defined culture system utilizing the non-biological substrate N-1[3-(trimethoxysilyl)propyl]-diethylenetriamine (DETA). Based on morphological and immunocytochemical criteria, Nrg 1-beta-1 treatment of developing myotubes increases the ratio of nuclear bag fibers to total myotubes from 0.019 to 0.100, approximately a five-fold increase. The myotube cultures were evaluated for expression of the intrafusal fiber-specific alpha cardiac-like myosin heavy chain and for the expression of the non-specific slow myosin heavy chain. Additionally, the expression of ErbB2 receptors on all myotubes was observed, while phosphorylated ErbB2 receptors were only observed in Nrg 1-beta-1-treated intrafusal fibers. After Nrg 1-beta-1 treatment, we were able to observe the expression of the intrafusal fiber-specific transcription factor Egr3 only in fibers exhibiting the nuclear bag phenotype. Finally, nuclear bag fibers were characterized electrophysiologically for the first time in vitro. This data shows conclusively, in a serum-free system, that Nrg 1-beta-1 is necessary to drive specification of forming myotubes to the nuclear bag phenotype.

  16. Muscle fibers in the central nervous system of nemerteans: spatial organization and functional role.

    Science.gov (United States)

    Petrov, A A; Zaitseva, O V

    2012-08-01

    The system of muscle fibers associated with the brain and lateral nerve cords is present in all major groups of enoplan nemerteans. Unfortunately, very little is known about the functional role and spatial arrangement of these muscles of the central nervous system. This article examines the architecture of the musculature of the central nervous system in two species of monostiliferous nemerteans (Emplectonema gracile and Tetrastemma cf. candidum) using phalloidin staining and confocal microscopy. The article also briefly discusses the body-wall musculature and the muscles of the cephalic region. In both species, the lateral nerve cords possess two pairs of cardinal muscles that run the length of the nerve cords and pass through the ventral cerebral ganglia. A system of peripheral muscles forms a meshwork around the lateral nerve cords in E. gracile. The actin-rich processes that ramify within the nerve cords in E. gracile (transverse fibers) might represent a separate population of glia-like cells or sarcoplasmic projections of the peripheral muscles of the central nervous system. The lateral nerve cords in T. cf. candidum lack peripheral muscles but have muscles similar in their position and orientation to the transverse fibers. The musculature of the central nervous system is hypothesized to function as a support system for the lateral nerve cords and brain, preventing rupturing and herniation of the nervous tissue during locomotion. The occurrence of muscles of the central nervous system in nemerteans and other groups and their possible relevance in taxonomy are discussed.

  17. Large field distributed aperture laser semiactive angle measurement system design with imaging fiber bundles.

    Science.gov (United States)

    Xu, Chunyun; Cheng, Haobo; Feng, Yunpeng; Jing, Xiaoli

    2016-09-01

    A type of laser semiactive angle measurement system is designed for target detecting and tracking. Only one detector is used to detect target location from four distributed aperture optical systems through a 4×1 imaging fiber bundle. A telecentric optical system in image space is designed to increase the efficiency of imaging fiber bundles. According to the working principle of a four-quadrant (4Q) detector, fiber diamond alignment is adopted between an optical system and a 4Q detector. The structure of the laser semiactive angle measurement system is, we believe, novel. Tolerance analysis is carried out to determine tolerance limits of manufacture and installation errors of the optical system. The performance of the proposed method is identified by computer simulations and experiments. It is demonstrated that the linear region of the system is ±12°, with measurement error of better than 0.2°. In general, this new system can be used with large field of view and high accuracy, providing an efficient, stable, and fast method for angle measurement in practical situations.

  18. EFFECTS OF PRESSURE AND TEMPERATURE ON ULTRAFILTRATION HOLLOW FIBER MEMBRANE IN MOBILE WATER TREATMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    ROSDIANAH RAMLI

    2016-07-01

    Full Text Available In Sabah, Malaysia, there are still high probability of limited clean water access in rural area and disaster site. Few villages had been affected in Pitas due to improper road access, thus building a water treatment plant there might not be feasible. Recently, Kundasang area had been affected by earthquake that caused water disruption to its people due to the damage in the underground pipes and water tanks. It has been known that membrane technology brought ease in making mobile water treatment system that can be transported to rural or disaster area. In this study, hollow fiber membrane used in a mobile water treatment system due to compact and ease setup. Hollow fiber membrane was fabricated into small module at 15 and 30 fibers to suit the mobile water treatment system for potable water production of at least 80 L/day per operation. The effects of transmembrane pressure (TMP and feed water temperature were investigated. It was found that permeate flux increases by more than 96% for both 15 and 30 fiber bundles with increasing pressure in the range of 0.25 to 3.0 bar but dropped when the pressure reached maximum. Lower temperature of 17 to 18˚C increase the water viscosity by 15% from normal temperature of water at 24˚C, making the permeate flux decreases. The fabricated modules effectively removed 96% turbidity of the surface water sample tested.

  19. Implementing and testing a fiber-optic polarization-based intrusion detection system

    Science.gov (United States)

    Hajj, Rasha El; MacDonald, Gregory; Verma, Pramode; Huck, Robert

    2015-09-01

    We describe a layer-1-based intrusion detection system for fiber-optic-based networks. Layer-1-based intrusion detection represents a significant elevation in security as it prohibits an adversary from obtaining information in the first place (no cryptanalysis is possible). We describe the experimental setup of the intrusion detection system, which is based on monitoring the behavior of certain attributes of light both in unperturbed and perturbed optical fiber links. The system was tested with optical fiber links of various lengths and types, under different environmental conditions, and under changes in fiber geometry similar to what is experienced during tapping activity. Comparison of the results for perturbed and unperturbed links has shown that the state of polarization is more sensitive to intrusion activity than the degree of polarization or power of the received light. The testing was conducted in a simulated telecommunication network environment that included both underground and aerial links. The links were monitored for intrusion activity. Attempts to tap the link were easily detected with no apparent degradation in the visual quality of the real-time surveillance video.

  20. Experimental investigation of inter-core crosstalk tolerance of MIMO-OFDM/OQAM radio over multicore fiber system.

    Science.gov (United States)

    He, Jiale; Li, Borui; Deng, Lei; Tang, Ming; Gan, Lin; Fu, Songnian; Shum, Perry Ping; Liu, Deming

    2016-06-13

    In this paper, the feasibility of space division multiplexing for optical wireless fronthaul systems is experimentally demonstrated by implementing high speed MIMO-OFDM/OQAM radio signals over 20km 7-core fiber and 0.4m wireless link. Moreover, the impact of optical inter-core crosstalk in multicore fibers on the proposed MIMO-OFDM/OQAM radio over fiber system is experimentally evaluated in both SISO and MIMO configurations for comparison. The experimental results show that the inter-core crosstalk tolerance of the proposed radio over fiber system can be relaxed to -10 dB by using the proposed MIMO-OFDM/OQAM processing. These results could guide high density multicore fiber design to support a large number of antenna modules and a higher density of radio-access points for potential applications in 5G cellular system.

  1. Development of an Optical Fiber Sensor Interrogation System for Vibration Analysis

    Directory of Open Access Journals (Sweden)

    Alfredo Lamberti

    2016-01-01

    Full Text Available Since the introduction of dynamic optical fiber sensor interrogation systems on the market it has become possible to perform vibration measurements at frequencies up to a few kHz. Nevertheless, the use of these sensors in vibration analysis has not become a standard practice yet. This is mainly caused by the fact that interrogators are stand-alone systems which focus on strain measurements while other types of signals are also required for vibration analysis (e.g., force signals. In this paper, we present a fiber Bragg grating (FBG interrogation system that enables accurate strain measurement simultaneously with other signals (e.g., excitation forces. The system is based on a Vertical Cavity Surface Emitting Laser (VCSEL and can easily be assembled with relatively low-cost off-the-shelf components. Dynamic measurements up to a few tens of kHz with a dynamic precision of around 3 nanostrain per square-root Hz can be performed. We evaluate the proposed system on two measurement examples: a steel beam with FBG sensors glued on top and a composite test specimen with a fiber sensor integrated within the material. We show that in the latter case the results of the interrogation system are superior in quality compared to a state-of-the-art commercially available interrogation system.

  2. Spatial-Resolution Improvement in Optical Frequency Domain Reflectometry System Based on Tunable Linear Fiber Laser

    Energy Technology Data Exchange (ETDEWEB)

    Li Guoyu; Li Yan [Institute of Information Engineering, Handan College, Handan, 056005 (China); Zhao Peng, E-mail: guoyu_li@yahoo.cn [School of Physics and Optoelectronic Engineering, Dalian University of Technology, Dalian 116024 (China)

    2011-02-01

    In optical frequency domain reflectometry (OFDR) system, the spatial resolution is obtained by using the total frequency-sweep span of the tunable laser. However, in practice, the spatial resolution is severely limited by nonlinearity in the lightwave-frequency sweep of the tunable laser. A closed-loop PZT modulated DBR linear fiber laser is proposed to improve the spatial resolution of the OFDR system. Experimental results show that the spatial resolution of OFDR system has improved greatly. When the frequency sweep excursion is 66GHz and the fiber under test (FUT) is 7 m, the OFDR system has a spatial resolution of 1.5 m with open-loop PZT modulated laser. But the spatial resolution increases to 35 cm with closed-loop PZT modulated laser.

  3. Analysis of errors induced by λ/4 wave plate in fiber-optic current sensor system

    Institute of Scientific and Technical Information of China (English)

    杨瑞峰

    2008-01-01

    1/4λ wave plate is a key element in the fiber-optic current sensor system. When a retardation error or an orientation error of birefringence axes of 1/4λ wave plate with respect to the hi-bi fiber axes occurs in the 1/4λ wave plate, the sensor system will output a wrong result of the measured current. The contributions of these two errors to the final result of the whole system were studied and the errors functions were deduced by establishing the measurement function of the current sensor system with Jones matrixes of the optical elements. The results show that that the greater the orientation error or the retardation error, the larger the final error, and that these two errors cannot be compensated each other.

  4. Fiber-wireless convergence in next-generation communication networks systems, architectures, and management

    CERN Document Server

    Chang, Gee-Kung; Ellinas, Georgios

    2017-01-01

    This book investigates new enabling technologies for Fi-Wi convergence. The editors discuss Fi-Wi technologies at the three major network levels involved in the path towards convergence: system level, network architecture level, and network management level. The main topics will be: a. At system level: Radio over Fiber (digitalized vs. analogic, standardization, E-band and beyond) and 5G wireless technologies; b. Network architecture level: NGPON, WDM-PON, BBU Hotelling, Cloud Radio Access Networks (C-RANs), HetNets. c. Network management level: SDN for convergence, Next-generation Point-of-Presence, Wi-Fi LTE Handover, Cooperative MultiPoint. • Addresses the Fi-Wi convergence issues at three different levels, namely at the system level, network architecture level, and network management level • Provides approaches in communication systems, network architecture, and management that are expected to steer the evolution towards fiber-wireless convergence • Contributions from leading experts in the field of...

  5. Potential for integrated optical circuits in advanced aircraft with fiber optic control and monitoring systems

    Science.gov (United States)

    Baumbick, Robert

    1991-01-01

    The current Fiber Optic Control System Integration (FOCSI) program is reviewed and the potential role of IOCs in FOCSI applications is described. The program is intended for building, environmentally testing, and demonstrating operation in piggyback flight tests (no active control with optical sensors) of a representative sensor system for propulsion and flight control. The optical sensor systems are to be designed to fit alongside the bill-of-materials sensors for comparison. The sensors are to be connected to electrooptic architecture cards which will contain the optical sources and detectors to recover and process the modulated optical signals. The FOCSI program is to collect data on the behavior of passive optical sensor systems in a flight environment and provide valuable information on installation amd maintenance problems for this technology, as well as component survivability (light sources, connectors, optical fibers, etc.).

  6. Small Explorer Data System MIL-STD-1773 fiber optic bus

    Science.gov (United States)

    Flanegan, Mark; Label, Ken

    1992-06-01

    The MIL-STD-1773 Fiber Optic Data Bus as implemented in the GSFC Small Explorer Data System (SEDS) for the Small Explorer Program is described. It provides an overview of the SEDS MIL-STD-1773 bus components system design considerations, reliability figures, acceptance and qualification testing requirements, radiation requirements and tests, error handling considerations, and component heritage. The first mission using the bus will be launched in June of 1992.

  7. Stiffness and Strength of Fiber Reinforced Polymer Composite Bridge Deck Systems

    OpenAIRE

    2002-01-01

    This research investigates two principal characteristics that are of primary importance in Fiber Reinforced Polymer (FRP) bridge deck applications: STIFFNESS and STRENGTH. The research was undertaken by investigating the stiffness and strength characteristics of the multi-cellular FRP bridge deck systems consisting of pultruded FRP shapes. A systematic analysis procedure was developed for the stiffness analysis of multi-cellular FRP deck systems. This procedure uses the Method of Elasti...

  8. Fiber-optic system for monitoring fast photoactivation dynamics of optical highlighter fluorescent proteins.

    Science.gov (United States)

    Pei, Zhiguo; Qin, Lingsong; Zhang, Zhihong; Zeng, Shaoqun; Huang, Zhen-Li

    2011-08-01

    Characterizing the photoactivation performance of optical highlighter fluorescent proteins is crucial to the realization of photoactivation localization microscopy. In contrast to those fluorescence-based approaches that require complex data processing and calibration procedures, here we report a simple and quantitative alternative, which relies on the measurement of small absorption spectra changes over time with a fiber-optic system. Using Dronpa as a representative highlighter protein, we have investigated the capacity of this system in monitoring the fast photoactivation process.

  9. Photoacoustic imaging of hidden dental caries by using a fiber-based probing system

    Science.gov (United States)

    Koyama, Takuya; Kakino, Satoko; Matsuura, Yuji

    2017-04-01

    Photoacoustic method to detect hidden dental caries is proposed. It was found that high frequency ultrasonic waves are generated from hidden carious part when radiating laser light to occlusal surface of model tooth. By making a map of intensity of these high frequency components, photoacoustic images of hidden caries were successfully obtained. A photoacoustic imaging system using a bundle of hollow optical fiber was fabricated for using clinical application, and clear photoacoustic image of hidden caries was also obtained by this system.

  10. μJ-level, kHz-repetition rate femtosecond fiber-CPA system at 1555 nm

    Science.gov (United States)

    Sobon, Grzegorz; Kaczmarek, Pawel; Gluszek, Aleksander; Sotor, Jaroslaw; Abramski, Krzysztof M.

    2015-07-01

    In this work, we demonstrate a high-power, fiber-based chirped pulse amplification (CPA) setup utilizing Er- and Er/Yb-doped fibers, operating at 1555 nm central wavelength. The integrated all-fiber pulse-picker allows to reduce the repetition frequency down to the kHz-range, which enables generation of sub-picosecond pulses with energies above 2 μJ and pulse peak power exceeding 1 MW. The system utilizes an Er/Yb co-doped large mode area fiber in the final amplification stage. Thanks to the used mode-field adapters and fiber-based components, the setup is almost fully fiberized, except the bulk grating pulse compressor. In order to provide compactness and simplicity, the compressor was designed using dense 1100 lines per millimeter gratings, that allow to keep the small grating separation.

  11. The Transmission Performance of Non-zero Dispersion Shifted Fiber Communication Systems Using In-line Phase-sensitive Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper focuses on the non-zero dispersion shifted fiber optical transmission system which employs cascaded in-line Phase-sensitive Amplifiers (PSAs). By computer simulation, we have revealed that the eye-penalty of high-speed signal pulses increases with the accretion of dispersion and the transmission distance limited by Intersymbol Interference (ISI) of signals varies with the spacing and average output power of amplifiers for positive and negative fiber dispersion. The analysis shows that although PSA can compensate for both positive and negative dispersion, it is only valid for small dispersion coefficient fiber. Owing to the effect of Self-phase-modulation (SPM), the ISI limited transmission distance of positive dispersion fiber is much longer than that of negative dispersion fiber. In addition, for positive fiber dispersion, there is an optimum value of average output signal power from PSA leading to the longest ISI limited transmission distance.

  12. The Transmission Performance of Non—zero Dispersion Shifted Fiber Communication Systems Using In—line Phase—sensitive Amplifiers

    Institute of Scientific and Technical Information of China (English)

    LINHong-rong; CHENRu-quan

    2001-01-01

    This paper focuses on the non-zero dispersion shifted fiber optical transmission system which employs cas-caded in-line Phase-sensitive Amplifiers(PSAs).By computer simulation, we have revealed that the eye-penalty of high-speed signal pulses increases with the accretion of dispersion and the transmission distance limited by Intersymbol Interference (ISI) of signals varies with the spacing and average output power of amplifiers for positive and nega-tive fiber dispersion.The analysis shows that although PSA can compensate for both positive and negative dispersion, it is only valid for small dispersion coefficient fiber.Owing to the effect of Self-phase-modulation (SPM), the ISI limited transmission distance of positive dispersion fiber is much longer than that of negative dispersion fiber.In ad-dition, for positive fiber dispersion,there is an optimum value of average output signal power from PSA leading to the longest ISI limited transmission distance.

  13. Experiment on 60-GHz MMW transmission performance in an optical fiber and wireless system

    Institute of Scientific and Technical Information of China (English)

    Qi Tang; Lin Chen; Jiangnan Xiao; Zizheng Cao

    2011-01-01

    We experimentally investigate the transmission performance of 60-GHz signals over standard single-mode fiber (SSMF) and wireless links at different bit rates.Experimental results show that in a transmission of over 10-km SSMF and 1.3-m wireless link, bit rate reaches up to 5 Gb/s and bit error rate (BER) is leas than 10-4.The main limiting factor in such radio-over-fiber (ROF) systems is intersymbol interferences caused by the so-called walk-off effect when BER is below 10-8.In addition, a transmission of over 20-km SSMF without chromatic dispersion compensation is briefly investigated.For a BER of 10-8, the optical penalty is 2 dB.%@@ We experimentally investigate the transmission performance of 60-GHz signals over standard single-mode fiber (SSMF) and wireless links at different bit rates.Experimental results show that in a transmission of over 10-km SSMF and 1.3-m wireless link, bit rate reaches up to 5 Gb/s and bit error rate (BER) is less than 10-4.The main limiting factor in such radio-over-fiber (ROF) systems is intersymbol interferences caused by the so-called walk-off effect when BER is below 10-8.In addition, a transmission of over 20-km SSMF without chromatic dispersion compensation is briefly investigated.For a BER of 10-s, the optical penalty is 2 dB.

  14. Comprehensive long distance and real-time pipeline monitoring system based on fiber optic sensing

    Energy Technology Data Exchange (ETDEWEB)

    Nikles, Marc; Ravet, Fabien; Briffod, Fabien [Omnisens S.A., Morges (Switzerland)

    2009-07-01

    An increasing number of pipelines are constructed in remote regions affected by harsh environmental conditions. These pipeline routes often cross mountain areas which are characterized by unstable grounds and where soil texture changes between winter and summer increase the probability of hazards. Due to the long distances to be monitored and the linear nature of pipelines, distributed fiber optic sensing techniques offer significant advantages and the capability to detect and localize pipeline disturbance with great precision. Furthermore pipeline owner/operators lay fiber optic cable parallel to transmission pipelines for telecommunication purposes and at minimum additional cost monitoring capabilities can be added to the communication system. The Brillouin-based Omnisens DITEST monitoring system has been used in several long distance pipeline projects. The technique is capable of measuring strain and temperature over 100's kilometers with meter spatial resolution. Dedicated fiber optic cables have been developed for continuous strain and temperature monitoring and their deployment along the pipeline has enabled permanent and continuous pipeline ground movement, intrusion and leak detection. This paper presents a description of the fiber optic Brillouin-based DITEST sensing technique, its measurement performance and limits, while addressing future perspectives for pipeline monitoring. (author)

  15. A 60GHz RoF(radio-over-fiber) transmission system based on PM modulator

    Science.gov (United States)

    Wang, Xin; Liu, Yi; Wang, Wen-Ting

    2016-11-01

    As one of the most important applications of microwave photonic ROF (Radio over Fiber) system which combines the advantages of optical communication and wireless communication is a good candidate for broadband mobile Communication In this paper, we built and simulation a 60GHz RoF(Radio-over-Fiber) transmission system based on PM modulator. First, we introduce the PM-IM(Phase modulation to intensity modulation) modulation mechanisms by the breaking the phase balanced approach. This method solves the problem that the constant envelope (phase modulation signal) generated by the phase modulator can not be directly detected by a photo detector. A standard single-mode fiber (SMF) is connected input to the F-P(Fabry-Perot) optical filter, which is to achieve the PM-IM modulation conversion by changing the wavelength of the laser or the frequency of the modulation factor of the F-P optical filter to adapt to different fiber lengths and the signal transmission rate. These two methods which changing the phase relationship between the optical carrier and the optical side band can realize the ideal phase transition to obtain efficient and low loss modulation conversion. Finally, the simulation results show that different fiber lengths and the signal transmission rate configuration of different wavelength of the laser or the frequency of the modulation factor of the F-P optical filter, the BER performance and the eye diagram of the 60GHz RoF transmission system signals have been improved based on these PM-IM modulation methods.

  16. Integrated Fiber Optic Sensor and Modeling System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced space fission systems are being developed as safe and affordable space propulsion alternatives for long-term space exploration. The characterization of...

  17. Novel Hemispherical Scanner for a Coherent Fiber LIDAR System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — LIDAR (LIght Detection And Ranging) systems have proven their value in the remote measurement of spatially resolved atmospheric wind velocities in a number of...

  18. Mutlifunctional Fibers for Energy Storage in Advanced EVA Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall objective of the Phase II effort is to demonstrate prototype multifunctional EVA system power patches that integrate energy storage into advanced space...

  19. Multi-band radio over fiber system with all-optical halfwave rectification, transmission and frequency down-conversion

    DEFF Research Database (Denmark)

    Prince, Kamau; Tafur Monroy, Idelfonso

    2011-01-01

    We introduce a novel application of all-optical half-wave rectification in the transportation and delivery of multi-frequency radio-over fiber signals. System evaluation was performed of transmission over various optical fiber types and all-optical envelope detection was implemented to achieve...

  20. System-Level Performance Evaluation of Microwave Fiber-Optic Links

    Science.gov (United States)

    Ackerman, Edward Irving

    Future generations of phased array radar systems as well as steerable communication antennas will require feed and distribution to many hundreds--possibly thousands --of solid-state MMIC radiating elements. In phased arrays operating at millimeter-wave frequencies, backplane interface and signal distribution methods will need to fulfill strict performance criteria. The metallic waveguides and coaxial cables currently used as phased array backplane interconnects will be unable to meet these stringent requirements. At millimeter-wave frequencies, where array backplane congestion is a major problem, distribution of the RF and digital control signals using optical fiber offers significant weight and crosstalk immunity advantages. To realize all the benefits of optical fiber signal distribution in a phased array, the single most critical development is the high-performance RF fiber-optic link. Some radar and communication systems, however, have such stringent transmit and/or receive performance goals which may not be easily met with conventional fiber-optic links. Fulfilling such difficult performance criteria requires prudent link architecture design. Before choosing a fiber-optic link design approach, it would benefit the phased array antenna system designer to possess a means of determining what RF performance could be expected. To do this, the designer needs a means of verifying that the mixing, modulation, and detection methods and the devices selected will result in a link with high -fidelity performance at the RF design frequencies. This work provides just such a design tool. In order to identify how best to leverage the advantages of optical fiber signal distribution in a microwave or millimeter-wave phased array, this thesis will investigate the optical link architectures that offer the maximum potential for achieving high-performance, low-profile array backplane interfaces. To assist the designer in the choice of signal mixing technique, modulation scheme, and

  1. Hybrid wireless-over-fiber transmission system based on multiple injection-locked FP LDs.

    Science.gov (United States)

    Li, Chung-Yi; Lu, Hai-Han; Chu, Chien-An; Ying, Cheng-Ling; Lu, Ting-Chien; Peng, Peng-Chun

    2015-07-27

    A hybrid wireless-over-fiber (WoF) transmission system based on multiple injection-locked Fabry-Perot laser diodes (FP LDs) is proposed and experimentally demonstrated. Unlike the traditional hybrid WoF transmission systems that require multiple distributed feedback (DFB) LDs to support different kinds of services, the proposed system employs multiple injection-locked FP LDs to provide different kinds of applications. Such a hybrid WoF transmission system delivers downstream intensity-modulated 20-GHz microwave (MW)/60-GHz millimeter-wave (MMW)/550-MHz cable television (CATV) signals and upstream phase-remodulated 20-GHz MW signal. Excellent bit error rate (BER), carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple-beat (CTB) are observed over a 40-km single-mode fiber (SMF) and a 4-m radio frequency (RF) wireless transport. Such a hybrid WoF transmission system has practical applications for fiber-wireless convergence to provide broadband integrated services, including telecommunication, data communication, and CATV services.

  2. On the use of a compact optical fiber sensor system in aircraft structural health monitoring

    Science.gov (United States)

    Mrad, Nezih; Guo, Honglei; Xiao, Gaozhi; Rocha, Bruno; Sun, Zhigang

    2012-06-01

    Structural Health Monitoring (SHM) has been identified as an area of significant potential for advanced aircraft maintenance programs that ensure continued airworthiness, enhanced operational safety and reduced life cycle cost. Several sensors and sensory systems have been developed for the implementation of such health monitoring capability. Among a wide range of developed technologies, fiber optic sensor technology, in particular fiber Bragg grating based emerged as one of the most promising for aircraft structural applications. This paper is set to explore the suitability of using a new Fiber Bragg Grating sensor (FBG) system developed for operation in two modes, low and high speed sensing modes, respectively. The suitability of the system for potential use in aircraft load monitoring and damage detection applications has been demonstrated. Results from FBG sensor system were in good agreement with results from conventional resistive strain gauges, validating this capability for load monitoring. For damage detection, the FBG sensor system was able to detect acoustic waves generated 52 inches (1.32 m) away. The initial results, obtained in a full stale experimentation, demonstrate the potential of using FBG sensors for both load monitoring and damage detection in aircraft environment.

  3. Application of optical system simulation software in a fiber optic telecommunications program

    Science.gov (United States)

    Koontz, Warren L. G.; Mandloi, Divya

    2004-10-01

    One of our objectives in the College of Applied Science and Technology at RIT is to offer our students some kind of "hands-on" experience along with theory. Providing a hands-on experience can be costly, however, especially in the field of optical communication. Although reasonably priced laboratory kits are available, the optical-electronic components in these kits are well below communication grade. Thus if we rely only on hardware, our students can only experiment with low power, low bit rate communication over a few kilometers of fiber. Computer simulation software offers an affordable alternative "hands-on" experience. With this software, a student can create a model of an optical system, execute the model and view measures of the system's performance. The system components can include DFB laser diodes, high-speed modulators, hundreds of kilometers of fiber, APD receivers and other optical and electrical components. The student can view the optical signals in the time or frequency domain, measure optical power and signal-to-noise ratio and much more. He or she can also view the effects of parameter variations or find the optimal value of a parameter. The software is easy to learn, especially if the student has previous experience with an electronic system simulator. This paper describes our application of an optical-electronic system simulator in the Telecommunications Engineering Technology program at RIT. We are developing a series of exercises to complement courses in fiber optic. These exercises will allow students to model and test systems that they have designed. We expect computer simulation to enhance our fiber optic courses significantly by adding a reasonably realistic and accessible test bed for student designs.

  4. Research on Fiber Optic Gyroscope Test Data Management System

    Directory of Open Access Journals (Sweden)

    Hongxia Cai

    2013-05-01

    Full Text Available FOG is a new type of angular velocity transducer; it is widely used in aviation, aerospace, marine and other fields. During FOG R & D, the test work costs long time, there are many test data in FOG life cycle, including structured data and unstructured data. This paper analyzed the FOG R & D process, and classified the test data. The paper also analyzed the test data management requirements and pointed out the main problems in the test data management. Based on this, test data management methods and test data management system architecture are given in this paper. Finally, a test data management system with B / S structure is developed.

  5. Robust, Brillouin Active Embedded Fiber-Is-The-Sensor System in Smart Composite Structures

    Science.gov (United States)

    Yu, Chung

    1996-01-01

    Extensive review of our proposed sensing scheme, based mainly on the forward Guided Acoustic Wave Brillouin Scattering (GAWBS) with backward stimulated Brillouin scattering (sBs) as an auxiliary scheme for system fault tolerance has been completed during this project period. This preliminary study is conducted for a number of reasons. The most significant reasons lie in the essential capability of the system to measure temperature and pressure. These two measurands have been proposed to be sensed by sBs in our proposal. Temperature and pressure/strain are important measurands in structural monitoring, so that the effectiveness of sensing by sBs needs to be further examined. It has been pointed out initially that sBs shift will be dependent on temperature and pressure/strain simultaneously. The shift versus temperature or strain is linear. Now, the question is how can these two measurands be separated when sBs is used to sense an environment, in which both temperature and strain are changing simultaneously. Typical sBs shift plotted versus strain and varying temperature is shown in Fig. 1. As is clear, a fiber initially stressed will relax with rising temperature. This is verified by a displacement to the right with rising temperature of the sBs shift vs strain curves in the figure. A way to circumvent this ambiguity is by employing two fibers, one pre-stressed and the other is a free fiber. The latter will measure temperature and subtracting data in the latter fiber from those of the former will give us net strain readings. This is a laborious approach, since it involves the use of two identical fibers, and this is hard to accomplish, especially when many sensors are needed. Additional multiplexing of the data stream for data subtraction becomes a necessity.

  6. Error Control Coding in Optical Fiber Communication Systems: An Overview

    Directory of Open Access Journals (Sweden)

    Majid Hatamian

    Full Text Available In sending data from one point to another, such as transferring data between various components of a computer system, due to the existence of electromagnetic waves and other issues such as noise and attenuation, information may be changed in the middle of ...

  7. Effect of complex optical field on the modulation instability of 100 km unrepeated fiber transmission system with DFRA

    Science.gov (United States)

    Yang, Yangyang; Xu, Pan; Hu, Zhengliang; Hu, Yongming

    2016-10-01

    With the development of networking technology and optical fiber sensor network technology, the use of optical fiber system to construct a large-scale, long distance optical fiber sensing network has become a hotspot of research. Optimizing the system to reach very long sensing ranges actually requires launching high pump and probe powers into the sensing fiber to provide a sufficient signal-to-noise ratio (SNR) on the measurements at the far end of the fiber. However, increasing the input power above a critical level excites undesired nonlinear effects such as the modulation instability (MI) and the stimulated Raman scattering (SRS), which deplete the pump and reduce the maximum sensing range of the system. Compared to SRS, MI shows a lower critical power and thus determines the maximum sensing range of a fiber sensor, so MI becomes the most important factor to limit the sensing range. In order to understand the MI in the system with the DFRA, we design a lot of experiments to test which factors will affect it in the system with distributed fiber Raman amplifier (DFRA) in this paper. From the threshold expression of MI and a lot of experiments, we found that the input power, the state of polarization, the phase and so on, have a significant impact on the system. According to the result of the experiments, we can find the Raman gain affects the MI and find some useful information for suppressing the MI in the later.

  8. Push-out Bond Strength of Fiber Posts to Intraradicular Dentin Using Multimode Adhesive System.

    Science.gov (United States)

    Oskoee, Siavash Savadi; Bahari, Mahmoud; Kimyai, Soodabeh; Asgary, Saeed; Katebi, Katayoun

    2016-12-01

    Because there is little information about bond strength of fiber posts cemented with a universal adhesive system (UAS) with different resin cements, the aim of this study was to compare the effect of different bonding strategies in the application of UASs on push-out bond strength of fiber posts to intraradicular dentin. Seventy-two single-rooted teeth were randomly divided into 6 groups: self-adhesive resin cement (SAC), dual-cure resin cement (DCC), UAS in the etch-and-rinse (E&R) mode and SAC (E&R + SAC), UAS in the self-etch (SE) mode and SAC (SE + SAC), UAS in the E&R mode and DCC (E&R + DCC), and UAS in the SE mode and DCC (SE + DCC). The push-out test was conducted at a crosshead speed of 0.5 mm/min. Data were analyzed with 2-way analysis of variance (P strategies (P  .05). ClearfilSA Luting SAC (Kuraray Noritake Dental Inc, New York, NY) cannot be used alone for fiber post adhesion; it needs an adhesive. Universal adhesive in the SE mode is suggested. When UAS is used for luting fiber posts, the type of cement does not have any effect on bond strength. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  9. Monitoring Composite Material Pressure Vessels with a Fiber-Optic/Microelectronic Sensor System

    Science.gov (United States)

    Klimcak, C.; Jaduszliwer, B.

    1995-01-01

    We discuss the concept of an integrated, fiber-optic/microelectronic distributed sensor system that can monitor composite material pressure vessels for Air Force space systems to provide assessments of the overall health and integrity of the vessel throughout its entire operating history from birth to end of life. The fiber optic component would include either a semiconductor light emitting diode or diode laser and a multiplexed fiber optic sensing network incorporating Bragg grating sensors capable of detecting internal temperature and strain. The microelectronic components include a power source, a pulsed laser driver, time domain data acquisition hardware, a microprocessor, a data storage device, and a communication interface. The sensing system would be incorporated within the composite during its manufacture. The microelectronic data acquisition and logging system would record the environmental conditions to which the vessel has been subjected to during its storage and transit, e.g., the history of thermal excursions, pressure loading data, the occurrence of mechanical impacts, the presence of changing internal strain due to aging, delamination, material decomposition, etc. Data would be maintained din non-volatile memory for subsequent readout through a microcomputer interface.

  10. Investigation of a Pulsed 1550 nm Fiber Laser System

    Science.gov (United States)

    2015-12-15

    pulses would be to pulse the pump diodes . Currently , the pump diodes in this system are run continuous wave. In the future, the plan is to investigate...information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 2...for illuminator applications. Considerations which impact the wavelength to be used are the transmissivity of the atmosphere and the responsivity of

  11. Refractive index sensing using a multimode interference-based fiber sensor in a cavity ring-down system

    Science.gov (United States)

    Silva, Susana; Frazão, Orlando

    2017-04-01

    This work presents a multimode interference-based fiber sensor in a cavity ring-down system for sensing temperature-induced refractive index (RI) changes of water. The sensing head is based in multimodal interference (MMI) and it was placed inside the fiber loop cavity of the CRD system. A modulated laser source was used to send pulses down into the fiber loop cavity and an erbium-doped fiber amplifier (EDFA) was placed in the fiber ring to provide an observable signal with a reasonable decay time. The behavior of the sensing head to temperature was studied due to its intrinsic sensitivity to said parameter - a sensitivity of -1.6×10-9 μs/°C was attained. This allowed eliminating the temperature component from RI measurement of water and a linear sensitivity of 580 μs/RIU in the RI range of 1.324-1.331 was obtained.

  12. Fiber-Optic Magnetic-Field-Strength Measurement System for Lightning Detection

    Science.gov (United States)

    Gurecki, Jay; Scully, Robert; Davis, Allen; Kirkendall, Clay; Bucholtz, Frank

    2011-01-01

    A fiber-optic sensor system is designed to measure magnetic fields associated with a lightning stroke. Field vector magnitudes are detected and processed for multiple locations. Since physical limitations prevent the sensor elements from being located in close proximity to highly conductive materials such as aluminum, the copper wire sensor elements (3) are located inside a 4-cubic-in. (.66-cubic-cm) plastic housing sensor head and connected to a fiber-optic conversion module by shielded cabling, which is limited to the shortest length feasible. The signal path between the conversion module and the avionics unit which processes the signals are fiber optic, providing enhanced immunity from electromagnetic radiation incident in the vicinity of the measurements. The sensors are passive, lightweight, and much smaller than commercial B-dot sensors in the configuration which measures a three-dimensional magnetic field. The system is expandable, and provides a standard-format output signal for downstream processing. Inside of the sensor head, three small search coils, each having a few turns on a circular form, are mounted orthogonally inside the non-metallic housing. The fiber-optic conversion module comprises three interferometers, one for each search coil. Each interferometer has a high bandwidth optical phase modulator that impresses the signal received from its search coil onto its output. The output of each interferometer travels by fiber optic cable to the avionics unit, and the search coil signal is recovered by an optical phase demodulator. The output of each demodulator is fed to an analog-to-digital converter, whose sampling rate is determined by the maximum expected rate of rise and peak signal magnitude. The output of the digital processor is a faithful reproduction of the coil response to the incident magnetic field. This information is provided in a standard output format on a 50-ohm port that can be connected to any number of data collection and processing

  13. Optical-fiber-connected 300-GHz FM-CW radar system

    Science.gov (United States)

    Kanno, Atsushi; Sekine, Norihiko; Kasamatsu, Akifumi; Yamamoto, Naokatsu; Kawanishi, Tetsuya

    2017-05-01

    300-GHz frequency-modulated continuous-wave (FM-CW) radar system operated by radio over fiber technologies is configured and demonstrated. Centralized signal generator, which is based on an optical frequency comb generation, provides high-precise FM-CW radar signal. The optical signal is easy to be transported to radar heads through an optical fiber network. Optical-modulator-based optical frequency comb generator is utilized as an optical frequency multiplier from a microwave signal to a 300-GHz terahertz signal by an optical modulation technique. In the study, we discuss the configuration of the network, signal generator and remote radar head for terahertz-wave multi-static radar system.

  14. Regularity properties of fiber derivatives associated with higher-order mechanical systems

    Science.gov (United States)

    Colombo, Leonardo; Prieto-Martínez, Pedro Daniel

    2016-08-01

    The aim of this work is to study fiber derivatives associated to Lagrangian and Hamiltonian functions describing the dynamics of a higher-order autonomous dynamical system. More precisely, given a function in T∗T(k-1)Q, we find necessary and sufficient conditions for such a function to describe the dynamics of a kth-order autonomous dynamical system, thus being a kth-order Hamiltonian function. Then, we give a suitable definition of (hyper)regularity for these higher-order Hamiltonian functions in terms of their fiber derivative. In addition, we also study an alternative characterization of the dynamics in Lagrangian submanifolds in terms of the solutions of the higher-order Euler-Lagrange equations.

  15. Fiber laser-microscope system for femtosecond photodisruption of biological samples.

    Science.gov (United States)

    Yavaş, Seydi; Erdogan, Mutlu; Gürel, Kutan; Ilday, F Ömer; Eldeniz, Y Burak; Tazebay, Uygar H

    2012-03-01

    We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells.

  16. Experimental Demonstration of 5-Gb/s Polarization-Multiplexed Fiber-Wireless MIMO Systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Pang, Xiaodan; Deng, Lei;

    2011-01-01

    We experimentally demonstrate a 5-Gb/s fiber-wireless transmission system combining optical polarization-division-multiplexing (PDM) and wireless multiple-input, multiple-output (MIMO) spatial multiplexing technologies. The optical-wireless channel throughput is enhanced by achieving a 4b...... advantageous to the MIMO wireless system due to the inter-channel delay insensitivity. The hybrid transmission performance of 26km fiber and up to 2m wireless MIMO is investigated......./s/Hz spectral efficiency. Based on the implementation of constant modulus algorithm (CMA), the 2×2 MIMO wireless channel is characterized and adaptively equalized for signal demodulation. The performance of the CMA-based channel adaptation is studied and it is revealed that the algorithm is particularly...

  17. Centralized optical-frequency-comb-based RF carrier generator for DWDM fiber-wireless access systems

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Beltran, Marta; Sanchez, Jose;

    2014-01-01

    In this paper, we report on a gigabit capacity fiber-wireless system that enables smooth integration between high-speed wireless networks and dense wavelength-division-multiplexing (DWDM) access networks. By employing a centralized optical frequency comb, both the wireline and the wireless services....... For demonstration, we transmit a 2.5 Gbit/s signal through the proposed system and successfully achieve a bit-error-rate (BER) performance well below the 7% overhead forward error correction limit of the BER of 2 × 10¿3 for both the wireline and the wireless signals in the 60 GHz band after 25 km single-mode fiber...... for each DWDM user can be simultaneously supported. Besides, each baseband channel can be transparently upconverted tomultiple radio-frequency (RF) bands for different wireless standards, which can be flexibly filtered at the end user to select the on-demand RF band, depending on the wireless applications...

  18. Sub-picosecond double-clad photonic crystal fiber oscillator and amplifier system

    Science.gov (United States)

    Li, Pingxue; Zhang, Mengmeng; Liang, Boxing; Chi, Junjie

    2015-08-01

    A ytterbium-doped large mode area PCF sub-picosecond laser oscillator and amplifier system is experimentally studied. The oscillator which combines NPE and SESAM is operating on the all-normal-dispersion regime and the LMA PCF is used as the gain medium. In the CW mode-locking regime, the oscillator directly generates the pulse at the repetition rate of 83.7 MHz while the pulse duration is 960 fs. The double-clad fiber amplifier system directly generates a high average power of 12.53 W with a pulse duration of 4.1 ps corresponding to the pulse energy of 150 nJ and peak power of 36.6 KW after about 3 m ytterbium doped double clad fiber amplification.

  19. All-fiber photonic devices and system for advanced optical communications

    Science.gov (United States)

    Dong, Xiaoyi; Qin, Zixiong; Ding, Lei; Yuan, Shuzhong; Kai, Guiyun; Liu, Zhiguo; Feng, Dejun; Zhao, Chunliu; Ma, Ning; Zhang, Ying; Ning, Ding

    2000-10-01

    The objective of this paper is to give an overview of the different studies we have performed at the research level regarding the design and implementation of a photonic wavelength division multiplexing layer providing transparent transport services to client layer. Such a network requires a number of enabling factors to be accessed in order to become a reality. Among these factors are the availability of high- capacity WDM transmission systems and efficient optical routing nodes based on mature technology, etc. In this paper, based on several key build blocks we developed such as fiber lasers, flattened EDFA's, and WADM's, an all-fiber WDM system was demonstrated. A cost effective alternative to OSA was proposed.

  20. Optical fiber communication systems with Matlab and Simulink models

    CERN Document Server

    Binh, Le Nguyen

    2014-01-01

    ""This book adds an aspect of programming and simulation not so well developed in other books. It is complete in this sense and enables directly linking the physics of optical components and systems to realistic results.""-Martin Rochette, Associate Professor, McGill University, Quebec, Canada""…this will be an excellent textbook since it has all new development and information on optical communication systems…I think this book can easily replace many other textbooks in this field.""-Massoud Moussavi, California State Polytechnic University-Pomona""The book is well written. It describes the fu

  1. Microstructured plastic optical fibers for applications in FTTH systems

    Science.gov (United States)

    Welikow, K.; Gdula, P.; Szczepański, P.; Buczyński, R.; Piramidowicz, R.

    2012-04-01

    This work is focused on the selected aspects of designing of microstructured POF (mPOF) with relatively large core, limited modal dispersion and improved resistance to bending losses, discussed in the context of its possible application in FTTH systems. The calculations confirmed the possibility of effective controlling both, the propagation and macrobending losses, as well as manipulation on the number of modes and modal area. The careful theoretical analysis allowed to design a series of geometries supporting the propagation of limited number of modes and, simultaneously, relatively large mode area together with limited bending losses.

  2. High-speed ultra-wideband wireless signals over fiber systems: photonic generation and DSP detection

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We firstly review the efforts in the literature on ultra-wideband (UWB)-over-fiber systems. Secondly, we present experimental results on photonic generation of high-speed UWB signals by both direct modulation and external optical injecting an uncooled semiconductor laser. Furthermore, we introduc...... the use of digital signal processing (DSP) technology to receive the generated UWB signal at 781.25 Mbit/s. Error-free transmission is achieved....

  3. High-speed ultra-wideband wireless signals over fiber systems: Photonic generation and DSP detection

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We firstly review the efforts in the literature on UWB over-fiber systems. Secondly, we present experimental results on photonic generation of high-speed UWB signals by both direct modulation and external optical injecting an uncooled semiconductor laser. Furthermore, we introduce the use of digi...... of digital signal processing (DSP) technology to receive the generated UWB signal at 781.25 Mbit/s. Error-free transmission is achieved....

  4. Apparatus and Method for Elimination of Polarization-Induced Fading in Fiber-optic Sensor System

    Science.gov (United States)

    Chan, Hon Man (Inventor); Parker, Jr., Allen R. (Inventor)

    2015-01-01

    The invention is an apparatus and method of eliminating polarization-induced fading in interferometric fiber-optic sensor system having a wavelength-swept laser optical signal. The interferometric return signal from the sensor arms are combined and provided to a multi-optical path detector assembly and ultimately to a data acquisition and processing unit by way of a switch that is time synchronized with the laser scan sweep cycle.

  5. Impact of Line Width and Power of Laser on Radio over Fiber System

    Science.gov (United States)

    Sharma, Sakshi; Bhatia, Kamaljeet Singh; Kaur, Harsimrat

    2015-03-01

    In order to increase the capacity of the existing optical communication networks advanced modulation schemes are utilized. Keeping this in view, an radio-over-fiber subcarrier multiplexing (SCM) employing ASK modulation technique is proposed. Response of the system is analysed by varying the linewidth and the power of the CW Laser and the optimum value is concluded for the same so as to achieve reliable communication.

  6. Towards events recognition in a distributed fiber-optic sensor system: Kolmogorov-Zurbenko filtering

    CERN Document Server

    Fedorov, Aleksey; Zhirnov, Andrey; Nesterov, Evgeniy; Namiot, Dmitry; Pnev, Alexey; Karasik, Valery

    2015-01-01

    The paper is about de-noising procedures aimed on events recognition in signals from a distributed fiber-optic vibration sensor system based on the phase-sensitive optical time-domain reflectometry. We report experimental results on recognition of several classes of events in a seismic background. A de-noising procedure uses the framework of the time-series analysis and Kolmogorov-Zurbenko filtering. We demonstrate that this approach allows revealing signatures of several classes of events.

  7. Multimode interference-based fiber sensor in a cavity ring-down system for refractive index measurement

    Science.gov (United States)

    Silva, Susana; Frazão, Orlando

    2017-06-01

    This work reports a multimode interference-based fiber sensor in a cavity ring-down system (CRD) for sensing temperature-induced refractive index (RI) changes of water. The sensing head is based in multimodal interference (MMI) and it is placed inside the fiber loop cavity of the CRD system. A modulated laser source was used to send pulses down into the fiber loop cavity and an erbium-doped fiber amplifier (EDFA) was placed in the fiber ring to provide an observable signal with a reasonable decay time. The behavior of the sensing head to temperature was studied due to its intrinsic sensitivity to said parameter - a sensitivity of -1.6×10-9 μs/°C was attained. This allowed eliminating the temperature component from RI measurement of water and a linear sensitivity of 580 μs/RIU in the RI range of 1.324-1.331 was obtained. The use of a MMI fiber sensor in the proposed CRD configuration allowed achieving a sensitivity ∼4-fold than that obtained with a tilted fiber Bragg grating and ∼2-fold than that when a micrometric channel inscribed in the fiber was used.

  8. Spreading of multiple Listeria monocytogenes abscesses via central nervous system fiber tracts: case report.

    Science.gov (United States)

    Bojanowski, Michel W; Seizeur, Romuald; Effendi, Khaled; Bourgouin, Patrick; Magro, Elsa; Letourneau-Guillon, Laurent

    2015-12-01

    Animal studies have shown that Listeria monocytogenes can probably access the brain through a peripheral intraneural route, and it has been suggested that a similar process may occur in humans. However, thus far, its spreading through the central nervous system (CNS) has not been completely elucidated. The authors present a case of multiple L. monocytogenes cerebral abscesses characterized by a pattern of distribution that suggested spread along white matter fiber tracts and reviewed the literature to identify other cases for analysis. They elected to include only those cases with 3 or more cerebral abscesses to make sure that the distribution was not random, but rather followed a pattern. In addition, they included those cases with abscesses in both the brainstem and the cerebral hemispheres, but excluded cases in which abscesses were located solely in the brainstem. Of 77 cases of L. monocytogenes CNS abscesses found in the literature, 17 involved multiple abscesses. Of those, 6 were excluded for lack of imaging and 3 because they involved only the brainstem. Of the 8 remaining cases from the literature, one was a case of bilateral abscesses that did not follow a fiber tract; another was also bilateral, but with lesions appearing to follow fiber tracts on one side; and in the remaining 6, to which the authors added their own case for a total of 7, all the abscesses were located exclusively in the same hemisphere and distributed along white matter fiber tracts. The findings suggest that after entering the CNS, L. monocytogenes travels within the axons, resulting in a characteristic pattern of distribution of multiple abscesses along the white matter fiber tracts in the brain. This report is the first description suggesting intraaxonal CNS spread of L. monocytogenes infection in humans following its entry into the brain. This distinct pattern is clearly seen on imaging and its recognition may be valuable in the diagnosis of listeriosis. This finding may allow for

  9. Algorithm for a novel fiber-optic weigh-in-motion sensor system

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, K.W. Jr.; Muhs, J.D.

    1991-08-01

    Over the past decade, the demand from both government and private industry for small, lightweight, vehicle weigh-in-motion (WIM) systems has grown substantially. During the 1980s several techniques for weighing vehicles in motion were developed that include piezoelectric cables, capacitive mats, and hydraulic and bending-plate load cells. These different systems have advantages and disadvantages that trade off between accuracy, physical size and system complexity. The smaller portable systems demonstrate medium to poor accuracy and repeatability while the larger more accurate systems are nonportable. A small, lightweight, and portable WIM system based on a fiber-optic pressure transducer has been developed by Oak Ridge National Laboratory (ORNL) to meet the demands of government and industry. The algorithm for extracting vehicle weight from the time-dependent sensor response is developed and presented in this report, along with data collected by the system for several classes of vehicles. These results show that the ORNL fiber-optic WIM system is a viable alternative to other commercial systems that are presently available. 5 refs., 5 figs.

  10. An Intrusion Detection System for the Protection of Railway Assets Using Fiber Bragg Grating Sensors

    Directory of Open Access Journals (Sweden)

    Angelo Catalano

    2014-09-01

    Full Text Available We demonstrate the ability of Fiber Bragg Gratings (FBGs sensors to protect large areas from unauthorized activities in railway scenarios such as stations or tunnels. We report on the technological strategy adopted to protect a specific depot, representative of a common scenario for security applications in the railway environment. One of the concerns in the protection of a railway area centers on the presence of rail-tracks, which cannot be obstructed with physical barriers. We propose an integrated optical fiber system composed of FBG strain sensors that can detect human intrusion for protection of the perimeter combined with FBG accelerometer sensors for protection of rail-track access. Several trials were carried out in indoor and outdoor environments. The results demonstrate that FBG strain sensors bonded under a ribbed rubber mat enable the detection of intruder break-in via the pressure induced on the mat, whereas the FBG accelerometers installed under the rails enable the detection of intruders walking close to the railroad tracks via the acoustic surface waves generated by footsteps. Based on a single enabling technology, this integrated system represents a valuable intrusion detection system for railway security and could be integrated with other sensing functionalities in the railway field using fiber optic technology.

  11. An intrusion detection system for the protection of railway assets using Fiber Bragg Grating sensors.

    Science.gov (United States)

    Catalano, Angelo; Bruno, Francesco Antonio; Pisco, Marco; Cutolo, Antonello; Cusano, Andrea

    2014-09-29

    We demonstrate the ability of Fiber Bragg Gratings (FBGs) sensors to protect large areas from unauthorized activities in railway scenarios such as stations or tunnels. We report on the technological strategy adopted to protect a specific depot, representative of a common scenario for security applications in the railway environment. One of the concerns in the protection of a railway area centers on the presence of rail-tracks, which cannot be obstructed with physical barriers. We propose an integrated optical fiber system composed of FBG strain sensors that can detect human intrusion for protection of the perimeter combined with FBG accelerometer sensors for protection of rail-track access. Several trials were carried out in indoor and outdoor environments. The results demonstrate that FBG strain sensors bonded under a ribbed rubber mat enable the detection of intruder break-in via the pressure induced on the mat, whereas the FBG accelerometers installed under the rails enable the detection of intruders walking close to the railroad tracks via the acoustic surface waves generated by footsteps. Based on a single enabling technology, this integrated system represents a valuable intrusion detection system for railway security and could be integrated with other sensing functionalities in the railway field using fiber optic technology.

  12. Micro-vision servo control of a multi-axis alignment system for optical fiber assembly

    Science.gov (United States)

    Chen, Weihai; Yu, Fei; Qu, Jianliang; Chen, Wenjie; Zhang, Jianbin

    2017-04-01

    This paper describes a novel optical fiber assembly system featuring a multi-axis alignment function based on micro-vision feedback control. It consists of an active parallel alignment mechanism, a passive compensation mechanism, a micro-gripper and a micro-vision servo control system. The active parallel alignment part is a parallelogram-based design with remote-center-of-motion (RCM) function to achieve precise rotation without fatal lateral motion. The passive mechanism, with five degrees of freedom (5-DOF), is used to implement passive compensation for multi-axis errors. A specially designed 1-DOF micro-gripper mounted onto the active parallel alignment platform is adopted to grasp and rotate the optical fiber. A micro-vision system equipped with two charge-coupled device (CCD) cameras is introduced to observe the small field of view and obtain multi-axis errors for servo feedback control. The two CCD cameras are installed in an orthogonal arrangement—thus the errors can be easily measured via the captured images. Meanwhile, a series of tracking and measurement algorithms based on specific features of the target objects are developed. Details of the force and displacement sensor information acquisition in the assembly experiment are also provided. An experiment demonstrates the validity of the proposed visual algorithm by achieving the task of eliminating errors and inserting an optical fiber to the U-groove accurately.

  13. Investigation of broadband digital predistortion for broadband radio over fiber transmission systems

    Science.gov (United States)

    Zhang, Xiupu; Liu, Taijun; Shen, Dongya

    2016-12-01

    In future broadband cloud radio access networks (C-RAN), front-haul transmission systems play a significant role in performance and cost of C-RAN. Broadband and high linearity radio over fiber (RoF) transmission systems are considered a promising solution for the front-haul. Digital linearization is one possible solution for RoF front-haul. In this paper, we investigate RF domain digital predistortion (DPD) linearization for broadband RoF front-haul. The implemented DPD is first investigated in 2.4 GHz WiFi over fiber transmission systems at 36 Mb/s, and more than 8-dB and 5.6-dB improvements of error vector magnitude (EVM) are achieved in back to back (BTB) and after 10 km single mode fiber (SMF) transmission. Further, both WiFi and ultra wide band (UWB) wireless signals are transmitted together, in which the DPD has linearization bandwidth of 2.4 GHz. It is shown that the implemented DPD leads to EVM improvements of 4.5-dB (BTB) and 3.1-dB (10 km SMF) for the WiFi signal, and 4.6-dB (BTB) and 4-dB (10 km SMF) for the broadband UWB signal.

  14. Sinusoidal phase-modulating fiber-optic interferometer fringe with a feedback control system.

    Science.gov (United States)

    Lv, Changrong; Duan, Fajie; Bo, En; Duan, Xiaojie; Feng, Fan; Fu, Xiao

    2014-09-20

    A displacement measurement system using a fiber-optic interferometer fringe projector with a feedback control system is presented and demonstrated. The system utilizes the integrating bucket method to detect the desired phase or the displacement and Fresnel reflection signal to realize measurement of the disturbance and feed it back to the modulated signal of the laser at the same time. The continuous signal truly reflects the error information, as the output light and reflected light share the same optical path. Practical experiments validate the feasibility of this method.

  15. A Calibration Method Based on Linear InGaAs in Fiber Grating Sensors Interrogation System

    Institute of Scientific and Technical Information of China (English)

    TAO Jun; ZHANG Xia

    2009-01-01

    In accordance with the characteristics of wavelength shift detection in fiber grating sensor interrogation system, the wavelength interrogation system which uses linear InGaAs as the spectrum receiver is proposed. Orientation of optic spectrum line affects the silt of volume phase grating and size of InGaAs photosensitive unit, thus the calibration method is needed. Based on an analysis of InGaAs imaging model, least square curve fitting method is proposed to detect spectrum wavelength and InGaAs photosensitive unit position. The experimental results show that the methods are effective and the demodulation system precision is improved.

  16. Underwater Optical Fiber Fluorescent System for Measuring Chlorophyll-a Concentration

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using optical fiber fluorescent technology,a new method for measuring alga concentration in water is presented. The system can realize on-line measurement for alga concentration using He-Ne laser as the light source. It can also effectively detect weak signals. The system with a passive sensor head has such advantages as simple structure, high sensitivity and high accuracy. It has been demonstrated that this system can be used to monitor water quality and can also be used to survey some matter.

  17. An Improved Hybrid Genetic Algorithm for Chemical Plant Layout Optimization with Novel Non-overlapping and Toxic Gas Dispersion Constraints

    Institute of Scientific and Technical Information of China (English)

    XU Yuan; WANG Zhenyu; ZHU Qunxiong

    2013-01-01

    New approaches for facility distribution in chemical plants are proposed including an improved non-overlapping constraint based on projection relationships of facilities and a novel toxic gas dispersion constraint.In consideration of the large number of variables in the plant layout model,our new method can significantly reduce the number of variables with their own projection relationships.Also,as toxic gas dispersion is a usual incident in a chemical plant,a simple approach to describe the gas leakage is proposed,which can clearly represent the constraints of potential emission source and sitting facilities.For solving the plant layout model,an improved genetic algorithm (GA) based on infeasible solution fix technique is proposed,which improves the globe search ability of GA.The case study and experiment show that a better layout plan can be obtained with our method,and the safety factors such as gas dispersion and minimum distances can be well handled in the solution.

  18. Theme--Achieving 2020. Goal 3: All Students Are Conversationally Literate in Agriculture, Food, Fiber, and Natural Resource Systems.

    Science.gov (United States)

    Trexler, Cary, Ed.

    2000-01-01

    Nine theme articles focus on the need for students to be conversationally literate about agriculture, food, fiber, and natural resources systems. Discusses the definition of conversational literacy, the human and institutional resources needed, and exemplary models for promoting literacy. (JOW)

  19. Transmission of 2.5 Gbit/s Spectrum-sliced WDM System for 50 km Single-mode Fiber

    Science.gov (United States)

    Ahmed, Nasim; Aljunid, Sayed Alwee; Ahmad, R. Badlisha; Fadil, Hilal Adnan; Rashid, Mohd Abdur

    2011-06-01

    The transmission of a spectrum-sliced WDM channel at 2.5 Gbit/s for 50 km of single mode fiber using an system channel spacing only 0.4 nm is reported. We have investigated the system performance using NRZ modulation format. The proposed system is compared with conventional system. The system performance is characterized as the bit-error-rate (BER) received against the system bit rates. Simulation results show that the NRZ modulation format performs well for 2.5 Gbit/s system bit rates. Using this narrow channel spectrum-sliced technique, the total number of multiplexed channels can be increased greatly in WDM system. Therefore, 0.4 nm channel spacing spectrum-sliced WDM system is highly recommended for the long distance optical access networks, like the Metro Area Network (MAN), Fiber-to-the-Building (FTTB) and Fiber-to-the-Home (FTTH).

  20. Modeling of carbon fiber couch attenuation properties with a commercial treatment planning system.

    Science.gov (United States)

    Mihaylov, I B; Corry, P; Yan, Y; Ratanatharathorn, V; Moros, E G

    2008-11-01

    The purpose of this work is to evaluate the modeling of carbon fiber couch attenuation properties with a commercial treatment planning system (TPS, Pinnacle3, v8.0d). A carbon fiber couch (Brain-Lab) was incorporated into the TPS by automatic contouring of all transverse CT slices. The couch shape and dimensions were set according to the vendor specifications. The couch composition was realized by assigning appropriate densities to the delineated contours. The couch modeling by the TPS was validated by absolute dosimetric measurements. A phantom consisting of several solid water slabs was CT scanned, the CT data set was imported into the TPS, and the carbon fiber couch was auto-contoured. Open (unblocked) field plans for different gantry angles and field sizes were generated. The doses to a point at 3 cm depth, placed at the linac isocenter, were computed. The phantom was irradiated according to the dose calculation setup and doses were measured with an ion chamber. In addition, percent depth dose (PDD) curves were computed as well as measured with radiographic film. The calculated and measured doses, transmissions, and PDDs were cross-compared. Doses for several posterior fields (0 degree, 30 degrees, 50 degrees, 75 degrees, 83 degrees) were calculated for 6 and 18 MV photon beams. For model validation a nominal field size of 10 x 10 cm2 was chosen and 100 MU were delivered for each portal. The largest difference between computed and measured doses for those posterior fields was within 1.7%. A comparison between computed and measured transmissions for the aforementioned fields was performed and the results were found to agree within 1.1%. The differences between computed and measured doses for different field sizes, ranging from 5 x 5 cm2 to 25 x 25 cm2 in 5 cm increments, were within 2%. Measured and computed PDD curves with and without the couch agree from the surface up to 30 cm depth. The PDDs indicate a surface dose increase resulting from the carbon fiber

  1. 85 km Long Reach PON System Using a Reflective SOA-EA Modulator and Distributed Raman Fiber Amplification

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Öhman, Filip; Yvind, Kresten

    2006-01-01

    We report on a bidirectional 85 km long reach PON system supported by distributed fiber Raman amplification with a record 7.5 Gb/s remote carrier modulated upstream signal by employing a reflective SOA-EA monolithically integrated circuit......We report on a bidirectional 85 km long reach PON system supported by distributed fiber Raman amplification with a record 7.5 Gb/s remote carrier modulated upstream signal by employing a reflective SOA-EA monolithically integrated circuit...

  2. Achievable information rates calculation for optical OFDM few-mode fiber long-haul transmission systems.

    Science.gov (United States)

    Lin, Changyu; Djordjevic, Ivan B; Zou, Ding

    2015-06-29

    We propose a method to estimate the lower bound of achievable information rates (AIRs) of high speed orthogonal frequency-division multiplexing (OFDM) in spatial division multiplexing (SDM) optical long-haul transmission systems. The estimation of AIR is based on the forward recursion of multidimensional super-symbol efficient sliding-window Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm. We consider most of the degradations of fiber links including nonlinear effects in few-mode fiber (FMF). This method does not consider the SDM as a simple multiplexer of independent data streams, but provides a super-symbol version for AIR calculation over spatial channels. This super-symbol version of AIR calculation algorithm, in principle, can be used for arbitrary multiple-input-multiple-output (MIMO)-SDM system with channel memory consideration. We illustrate this method by performing Monte Carlo simulations in a complete FMF model. Both channel model and algorithm for calculation of the AIRs are described in details. We also compare the AIRs results for QPSK/16QAM in both single mode fiber (SMF)- and FMF-based optical OFDM transmission.

  3. Development and Testing of a Post-Installable Deepwater Monitoring System Using Fiber-Optic Sensors

    Science.gov (United States)

    Seaman, Calvin H.; Brower, David V.; Le, Suy Q.; Tang, Henry H.

    2015-01-01

    This paper addresses the design and development of a fiber-optic monitoring system that can be deployed on existing deepwater risers and flowlines; and provides a summary of test article fabrication and the subsequent laboratory testing performed at the National Aeronautics and Space Administration-Johnson Space Center (NASA-JSC). A major challenge of a post-installed instrumentation system is to ensure adequate coupling between the instruments and the riser or flowline of interest. This work investigates the sensor coupling for pipelines that are suspended in a water column (from topside platform to seabed) using a fiber-optic sensor clamp and subsea bonding adhesive. The study involved the design, fabrication, and test of several prototype clamps that contained fiber-optic sensors. A mold was produced by NASA using 3-D printing methods that allowed the casting of polyurethane clamp test articles to accommodate 4-inch and 8-inch diameter pipes. The prototype clamps were installed with a subsea adhesive in a "wet" environment and then tested in the NASA Structures Test Laboratory (STL). The tension, compression, and bending test data showed that the prototype sensor clamps achieved good structural coupling, and could provide high quality strain measurement for active monitoring.

  4. High average power picosecond pulse generation from a thulium-doped all-fiber MOPA system.

    Science.gov (United States)

    Liu, Jiang; Wang, Qian; Wang, Pu

    2012-09-24

    We report a stable highly-integrated high power picosecond thulium-doped all-fiber MOPA system without using conventional chirped pulse amplification technique. The master oscillator was passively mode-locked by a SESAM to generate average power of 15 mW at a fundamental repetition rate of 103 MHz in a short linear cavity, and a uniform narrow bandwidth FBG is employed to stabilize the passively mode-locked laser operation. Two-stage double-clad thulium-doped all-fiber amplifiers were used directly to boost average power to 20.7 W. The laser center wavelength was 1962.8 nm and the pulse width was 18 ps. The single pulse energy and peak-power after the amplication were 200 nJ and 11.2 kW respectively. To the best of our knowledge, this is the highest average power ever reported for a picosecond thulium-doped all-fiber MOPA system.

  5. Stimulated Brillouin scattering-induced phase noise in an interferometric fiber sensing system

    Institute of Scientific and Technical Information of China (English)

    Chen Wei; Meng Zhou; Zhou Hui-Juan; Luo Hong

    2012-01-01

    Stimulated Brillouin scattering-induced phase noise is harmful to interferometric fiber sensing systems. Thelocalized fluctuating model is used to study the intensity noise caused by the stimulated Brillouin scattering in a single-mode fiber.The phase noise structure is analyzed for an interferometric fiber sensing system,and an unbalanced Michelson interferometer with an optical path difference of 1 m,as well as the phase-generated carrier technique,is used to measure the phase noise.It is found that the phase noise is small when the input power is below the stimulated Brillouin scattering threshold,increases dramatically at first and then gradually becomes fiat when the input power is above the threshold,which is similar to the variation in relative intensity noise.It can be inferred that the increase in phase noise is mainly due to the broadening of the laser linewidth caused by stimulated Brillouin scattering,which is verified through linewidth measurements in the absence and presence of the stimulated Brillouin scattering.

  6. Polarization-Dependent Optimization of Fiber-Coupled Terahertz Time-Domain Spectroscopy System

    Institute of Scientific and Technical Information of China (English)

    Jing Yang; Shan He; Jia-Yu Zhao; Lan-Jun Guo; Wei-Wei Liu

    2015-01-01

    Abstract¾The optimization of the fiber-coupled terahertz time-domain spectroscopy (THz-TDS) system is performed by changing the polarization of the optical excitation pulse centered at 1550nm. InGaAs/InAlAs multilayer structures based photoconductive antennas are used in TDS setup as both the emitter and receiver. The experimental results demonstrate that not only the THz signal power but also the temporal waveform vary with the rotation of the exciting pulse polarization. Maximum output power of the emitter is obtained when the polarization of the pump pulse is perpendicular to the edge of the metal electrodes. At this moment the THz waveform is close to a single-cycled pulse. However, double THz pulses could be recorded when the pump laser polarization is parallel to the electrodes. Laser pulse splitting induced by the birefringence of the optical fiber may attribute to the polarization- dependent performance of the fiber-coupled THz-TDS system.

  7. High Speed Submarine Optical Fiber Communication System:Pressure and Temperature Effects

    Directory of Open Access Journals (Sweden)

    A. A. Mohammed

    2012-07-01

    Full Text Available In the present paper, the performance of high speed submarine optical fiber cable systems is investigated, taking into account both the pressure and the temperature effects. Both the pressure and the temperature are depth-dependent variables, while both the spectral losses and the dispersion effects are temperature as well as wavelength dependent variables. Two important cases with real fibers are processed: a case with dispersion cancellation and a case without dispersion cancellation. It is found that the ocean pressure (due to the depth shifts the dispersion-free wavelength towards the third communication window. In general, as the depth increases the maximum transmitted bit rate increases in the range of interest. The system capacity as well as the spectral losses, and the dispersion effects are parametrically investigated over wide-range ranges of the set of affecting parameters {wavelength, ocean depth (and consequently the ocean pressure and temperature, and the chemical structure}. Key Words: Submarine Optical Fiber, Undersea Optical Communication, Pressure and Temperature Effects, Transoceanic Optical Communications

  8. Material characterization of several resin systems for high temperature carbon fiber reinforced composites

    Science.gov (United States)

    Yoon, Sung Ho; Oh, Jin Oh; Choi, Dong Hyun; Lee, Sang Woo

    2012-04-01

    Material characterization of several resin systems for high temperature carbon fiber reinforced composites was performed through a series of the tensile test, the dynamic mechanical analysis (DMA) test, and the strand test. The modified tensile specimens and the DMA specimens were used to evaluate the tensile and thermal analysis properties of resin systems. The strand specimens were used to evaluate the tensile properties and load transfer efficiencies of the specimens. Four types of resin systems were considered. One was a conventional resin system currently used for filament wound structures and other three were high temperature resin systems. According to the tensile and DMA test results, the tensile modulus decreases slightly and the tensile strength decreases rapidly until the temperature reaches glass transition temperature. The tensile modulus and tensile strength are almost negligible above glass transition temperature. The tensile modulus obtained from the tensile test is consistent with that from the DMA test at different temperatures. From the strand test results, considering, the load transfer efficiency is found to be around 87 to 90 % of the tensile strength of T800H-12K carbon fibers for all resin systems except the specimen with the Type 2. Finally we found that the Type 4 is the best candidate for high temperature resin system applicable to filament wound structures in the view of the glass transition temperature as well as the tensile properties.

  9. A system for respiratory motion detection using optical fibers embedded into textiles.

    Science.gov (United States)

    D'Angelo, L T; Weber, S; Honda, Y; Thiel, T; Narbonneau, F; Luth, T C

    2008-01-01

    In this contribution, a first prototype for mobile respiratory motion detection using optical fibers embedded into textiles is presented. The developed system consists of a T-shirt with an integrated fiber sensor and a portable monitoring unit with a wireless communication link enabling the data analysis and visualization on a PC. A great effort is done worldwide to develop mobile solutions for health monitoring of vital signs for patients needing continuous medical care. Wearable, comfortable and smart textiles incorporating sensors are good approaches to solve this problem. In most of the cases, electrical sensors are integrated, showing significant limits such as for the monitoring of anaesthetized patients during Magnetic Resonance Imaging (MRI). OFSETH (Optical Fibre Embedded into technical Textile for Healthcare) uses optical sensor technologies to extend the current capabilities of medical technical textiles.

  10. Effects of truncated Gaussian beam on the performance of fiber optical synthetic aperture system

    Institute of Scientific and Technical Information of China (English)

    LIU Li; WANG Chang-wei; JIANG Yue-song

    2012-01-01

    In the fiber optical synthetic aperture (FOSA) system,the diffraction of the Gaussian beam limited by the aperture in exit pupil plane of fiber collimator is studied theoretically,and the axial and transverse irradiance distributions are obtained.The point spread function (PSF) and modulation transfer function (MTF) of the truncated Gaussian beam array are computed numerically with different truncation factors.The results show that the diffraction of the truncated Gaussian beam array agrees with the uniform-beam Rayleigh diffraction when the truncation factor is less than 0.5,but little power is transmitted.The PSF and MTF are degraded,but more power can be contained when the truncation factor is larger.The selection of the truncation factor is a trade-off between the loss of transmission and the qualities of PSF and MTF in practical application.

  11. Robustness estimation of software-synchronized all-optical sampling for fiber communication systems

    Institute of Scientific and Technical Information of China (English)

    Aiying Yang; Xiangyu Wu; Yu'nan Sun

    2009-01-01

    The robustness of the software-synchronized all-optical sampling for optical performance monitoring is estimated for 10-Gb/s fiber communication systems. It reveals that the software-synchronized algorithm is sensitive to the signal degradation caused by chromatic dispersion and nonlinearity in optical fibers. The influence of timing jitter and amplitude fluctuation of the sampling pulses is also investigated. It is found that stringent requirements are imposed on the quality of the sampling pulse and the tolerance of l-dB Q penalty is measured. Considering the practically available optical sampling pulse sources, the results indicate that the amplitude fluctuation of the sampling pulses has the dominant impacts on the software-synchronized method.

  12. Modulated Pulses Based High Spatial Resolution Distributed Fiber System for Multi-Parameter Sensing

    CERN Document Server

    Zhang, Jingdong; Zhou, Huan; Li, Yang; Liu, Min; Huang, Wei

    2016-01-01

    We demonstrate a hybrid distributed fiber sensing system for multi-parameter detection. The integration of phase-sensitive optical time domain reflectometry ({\\Phi}-OTDR) and Brillouin optical time domain reflectometry (B-OTDR) enables measurement of vibration, temperature and strain. Exploiting the fast changing property of vibration and the static property of temperature and strain, the laser pulse width and intensity are modulated and then injected into the single-mode sensing fiber proportionally, so that the three concerned parameters can be extracted simultaneously by only one photo-detector and data acquisition channel. Combining with advanced data processing methods, the modulation of laser pulse brings additional advantages because of trade and balance between the backscattering light power and nonlinear effect noise, which enhances the signal-to-noise ratio, and enables sub-meter level spatial resolution together with long sensing distance. The proposed method realizes up to 4.8 kHz vibration sensin...

  13. Vacuum fiber-fiber coupler

    Science.gov (United States)

    Heinrici, Axel; Bjelajac, Goran; Jonkers, Jeroen; Jakobs, Stefan; Olschok, Simon; Reisgen, Uwe

    2017-02-01

    Research and development carried out by the ISF Welding and Joining Institute of RWTH Aachen University has proven that combining high power laser and low vacuum atmosphere provides a welding performance and quality, which is comparable to electron beam welding. The developed welding machines are still using a beam forming which takes place outside the vacuum and the focusing laser beam has to be introduced to the vacuum via a suitable window. This inflexible design spoils much of the flexibility of modern laser welding. With the target to bring a compact, lightweight flying optics with flexible laser transport fibers into vacuum chambers, a high power fiber-fiber coupler has been adapted by II-VI HIGHYAG that includes a reliable vacuum interface. The vacuum-fiber-fiber coupler (V-FFC) is tested with up to 16 kW sustained laser power and the design is flexible in terms of a wide variety of laser fiber plug systems and vacuum flanges. All that is needed to implement the V-FFC towards an existing or planned vacuum chamber is an aperture of at least 100 mm (4 inch) diameter with any type of vacuum or pressure flange. The V-FFC has a state-of-the-art safety interface which allows for fast fiber breakage detection for both fibers (as supported by fibers) by electric wire breakage and short circuit detection. Moreover, the System also provides connectors for cooling and electric signals for the laser beam optics inside the vacuum. The V-FFC has all necessary adjustment options for coupling the laser radiation to the receiving fiber.

  14. Analysis of the anatomy of the Papez circuit and adjoining limbic system by fiber dissection techniques.

    Science.gov (United States)

    Shah, Abhidha; Jhawar, Sukhdeep Singh; Goel, Atul

    2012-02-01

    Fiber dissection techniques were used to study the limbic system, in particular the Papez circuit. The course, length and anatomical relations of the structures that make up the Papez circuit were delineated. Ten previously frozen and formalin-fixed cadaveric human brains were used, and dissected according to the fiber dissection techniques of Klingler et al. (Schweiz Arch Neurol Psychiatry 1935;36:247-56). The primary dissection tools were thin and curved wooden and metallic spatulas with tips of varying sizes. We found that the Papez circuit (mean length: 350 mm) begins in the hippocampus and continues into the fornix to reach the mamillary body. From there, the mamillothalamic tract continues to the anterior nucleus of the thalamus, which in turn connects to the cingulum by means of anterior thalamic radiations (mean length: 30 mm). The cingulum courses around the corpus callosum to end in the entorhinal cortex, which then projects to the hippocampus, thus completing the circuit. The average length and breadth of the mamillothalamic tract was 18 mm and 1.73 mm respectively. The average length of the cingulum was 19.6 cm and that of the fornix was 71 mm. The entire circuit was anatomically dissected first in situ in the hemisphere and was then reconstructed outside after removing its various components using fine fiber dissection under a surgical microscope. We found that fiber dissection elegantly delineates the anatomical subtleties of the Papez circuit and provides a three-dimensional perspective of the limbic system. Intricate knowledge of the anatomy of this part of the brain aids the neurosurgeon while performing epilepsy surgery and while approaching intrinsic brain parenchymal, ventricular and paraventricular lesions.

  15. Object Matching Across Multiple Non-overlapping Fields of View Using Fuzzy Logic%基于模糊逻辑的多相机非重叠场景的物体匹配

    Institute of Scientific and Technical Information of China (English)

    LOKE Yuan Ren; KUMAR Pankaj; RANGANATH Surendra; 黄为民

    2006-01-01

    An approach based on fuzzy logic for matching both articulated and non-articulated objects across multiple non-overlapping field of views (FoVs) from multiple cameras is proposed.We call it fuzzy logic matching algorithm (FLMA). The approach uses the information of object motion, shape and camera topology for matching objects across camera views. The motion and shape information of targets are obtained by tracking them using a combination of ConDensation and CAMShift tracking algorithms. The information of camera topology is obtained and used by calculating the projective transformation of each view with the common ground plane. The algorithm is suitable for tracking non-rigid objects with both linear and non-linear motion. We show videos of tracking objects across multiple cameras based on FLMA. From our experiments, the system is able to correctly match the targets across views with a high accuracy.

  16. Digital predistortion of 75-110 GHz W-band frequency multiplier for fiber wireless short range access systems.

    Science.gov (United States)

    Zhao, Ying; Deng, Lei; Pang, Xiaodan; Yu, Xianbin; Zheng, Xiaoping; Zhang, Hanyi; Monroy, Idelfonso Tafur

    2011-12-12

    We present a W-band fiber-wireless transmission system based on a nonlinear frequency multiplier for high-speed wireless short range access applications. By implementing a baseband digital signal predistortion scheme, intensive nonlinear distortions induced in a sextuple frequency multiplier can be effectively pre-compensated. Without using costly W-band components, a transmission system with 26 km fiber and 4 m wireless transmission operating at 99.6 GHz is experimentally validated. Adjacent-channel power ratio (ACPR) improvements for IQ-modulated vector signals are guaranteed and transmission performances for fiber and wireless channels are studied. This W-band predistortion technique is a promising candidate for applications in high capacity wireless-fiber access systems.

  17. A high-efficiency fiber-based imaging system for co-registered autofluorescence and optical coherence tomography.

    Science.gov (United States)

    Pahlevaninezhad, Hamid; Lee, Anthony M D; Shaipanich, Tawimas; Raizada, Rashika; Cahill, Lucas; Hohert, Geoffrey; Yang, Victor X D; Lam, Stephen; MacAulay, Calum; Lane, Pierre

    2014-09-01

    We present a power-efficient fiber-based imaging system capable of co-registered autofluorescence imaging and optical coherence tomography (AF/OCT). The system employs a custom fiber optic rotary joint (FORJ) with an embedded dichroic mirror to efficiently combine the OCT and AF pathways. This three-port wavelength multiplexing FORJ setup has a throughput of more than 83% for collected AF emission, significantly more efficient compared to previously reported fiber-based methods. A custom 900 µm diameter catheter ‒ consisting of a rotating lens assembly, double-clad fiber (DCF), and torque cable in a stationary plastic tube ‒ was fabricated to allow AF/OCT imaging of small airways in vivo. We demonstrate the performance of this system ex vivo in resected porcine airway specimens and in vivo in human on fingers, in the oral cavity, and in peripheral airways.

  18. Digital predistortion of 75–110 GHz W-band frequency multiplier for fiber wireless short range access systems

    DEFF Research Database (Denmark)

    Zhao, Ying; Deng, Lei; Pang, Xiaodan

    2011-01-01

    We present a W-band fiber-wireless transmission system based on a nonlinear frequency multiplier for high-speed wireless short range access applications. By implementing a baseband digital signal predistortion scheme, intensive nonlinear distortions induced in a sextuple frequency multiplier can...... be effectively pre-compensated. Without using costly W-band components, a transmission system with 26km fiber and 4m wireless transmission operating at 99.6GHz is experimentally validated. Adjacent-channel power ratio (ACPR) improvements for IQ-modulated vector signals are guaranteed and transmission...... performances for fiber and wireless channels are studied. This W-band predistortion technique is a promising candidate for applications in high capacity wireless-fiber access systems....

  19. Design and Realization of Uniform Fiber Bragg Grating Used in Dense Wavelength Division Multiplexing Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Relation of optical properties in a uniform fiber Bragg grating(FBG) with its grating parameters and the laser beam engraving conditions is analyzed. The principle and method for designing the uniform FBG used in dense wavelength division multiplexing(DWDM) system is given. By adopting the double exposure technique, with a uniform phase mask and Gaussian laser beam, the uniform FBG used in DWDM system is designed and engraved, whose bandwidth of the main reflection band is about 0.4nm and 0.7nm at -5dB and -25dB respectively.

  20. Control of polarization signal distortion by frequency domain phase conjugation in optical fiber systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Optical frequency domain phase conjugation(FDPC) is based on phase conjuga-tion of spectrum of an input signal.It is equivalent to the phase conjugation and the time reversal of the temporal envelope of an input signal.The use of FDPC to con-trol polarization signal distortion in birefringent optical fiber systems is proposed.Evolution of polarization signals in the system using midway FDPC is analyzed theoretically and simulated numerically.It is shown that the distortion of polariza-tion signals can be controlled effectively by FDPC.The impairments due to disper-sion and nonlinear effects can be suppressed simultaneously.

  1. Control of polarization signal distortion by frequency domain phase conjusation in optical fiber systems

    Institute of Scientific and Technical Information of China (English)

    BU Yang; WANG XiangZhao

    2008-01-01

    Optical frequency domain phase conjugation (FDPC) is based on phase conjugation of spectrum of an input signal. It is equivalent to the phase conjugation and the time reversal of the temporal envelope of an input signal. The use of FDPC to con-trol polarization signal distortion in birefringent optical fiber systems is proposed. Evolution of polarization signals in the system using midway FDPC is analyzed theoretically and simulated numerically. It is shown that the distortion of polariza-tion signals can be controlled effectively by FDPC. The impairments due to disper-sion and nonlinear effects can be suppressed simultaneously.

  2. Small Field Dosimetry Using Optical-Fiber Radioluminescence and Radpos Dosimetry Systems

    DEFF Research Database (Denmark)

    Ploquin, N.; Kertzscher Schwencke, Gustavo Adolfo Vladimir; Vandervoort, E.

    2012-01-01

    Inc, USA). The RL signal generated in the crystal by ionizing radiation can be read remotely via thin optical fiber cables. The system was originally developed for in vivo dose verification during external beam radiotherapy and brachytherapy (Radiother Oncol, 100 (3), 45662, 2011). However, due....... Detector readings for each cone were normalized to those for 60 mm cone. For MOSFET detectors in both mobileMOSFET and RADPOS systems, the corrections proposed by Francescon et al. (J Appl Clin Med Phys, 10 (1), 14752, 2009) were applied. Since FWHM of our Cyberknife source is 2.4mm, the μ...

  3. Seamless Transmission between Single-Mode Optical Fibers Using Free Space Optics System

    Science.gov (United States)

    Yoshida, Koichi; Tsujimura, Takeshi

    This paper presents a free space optics system installed between two single-mode optical fibers (SMFs). The result looks as if the two SMFs were seamlessly connected without the need for any photoelectric devices. Misalignments between the two SMFs caused by disturbances are actively compensated for by introducing a laser beam controller that incorporates an opto-mechatronic mechanism with four degrees of freedom. Experiments using a prototype are conducted to verify the effectiveness of the proposed FSO system for initial beam acquisition and beam tracking when there is a vibration disturbance.

  4. Distributed acoustic sensing system using an identical weak fiber Bragg grating array

    Science.gov (United States)

    Liu, Sheng; Han, Xinying; Wen, Hongqiao

    2016-10-01

    We propose and experimentally demonstrate a distributed acoustic sensing system using an identical weak fiber Bragg grating array. Phase, frequency and location information of vibration can be demodulated by using a path-match interferometry method. 3×3 coupler demodulation technique is employed to eliminate signal fading in interferometer. Experiments on detecting acoustic wave generated by PZT show that the system is capable of measuring vibrations of up to 1000 Hz over 1.6 km with 2.5m spatial resolution.

  5. A practical distributed Fiber Bragg grating temperature sensor system based on STM32 processor platform

    Science.gov (United States)

    Liu, Jinjun; Cheng, Yongxin; Wang, Guangyu; Zhang, Yanjun

    2015-10-01

    A practical distributed FBG temperature sensor system based on STM32 processor platform is presented in this paper and this FBG sensing system can realize single-channel and multi-point temperature measurement. Because the measured area has been divided into several parts, every part has several fiber Bragg gratings with the same wavelength. There is no need to get the temperature of each point, just get the temperature field information of the parts. In other words, if the temperature of points is varied, the largest varied temperature of the points in one part can be obtained as the temperature of this part. So in the system only use one light source, but more FBGs can be implanted in a fiber, which can effectively reduce costs and complexity. In signal processing system, the FFP-TF control circuit cans precise control without distortion of FFP-TF; high precision photoelectric detection circuit can achieve nW level optical power detection; wavelength demodulation algorithm can achieve system synchronization. The PC monitoring software based on VC++ is used to display the monitoring interface. The experiment results indicated that temperature precision is 1°C and the linearity is over 99.6%. All experiments can be reproducible. It has been seen in experiments that the system has the characteristics of the high measured stable, good reliability, low cost and can meet the needs of the engineering measurements.

  6. Management of dispersion, nonlinearity and polarization-dependent effects in high-speed reconfigurable WDM fiber optic communication systems

    Science.gov (United States)

    Luo, Ting

    As optical communications approach more data bandwidth, longer transmission distance, and more reconfigurability, dispersion, nonlinearity and polarization-dependent effects are becoming key issues for future all-optical fiber optic systems and networks. For ≥10 Gbit/s optical fiber transmission systems, it is critical that chromatic dispersion and polarization-mode-dispersion be well monitored and compensated using some type of dispersion monitoring and compensation. On the other hand, dispersive and nonlinear effects in optical fiber systems can also be beneficial and have applications on pulse management, all-optical signal processing and network function, which will be essential for high bite-rate optical networks and replacing the expensive optical-electrical-optical (O/E/O) conversion. In this Ph.D. dissertation, we present a detailed research on dispersion, nonlinearity, and polarization-dependent effects in high-speed optical communication systems. We have demonstrated: (i) A dynamic channel-spacing tunable multi-wavelength Erbium-doped fiber laser; (ii) Chromatic-dispersion-insensitive PMD monitoring by tracking the radio-frequency extracted from the vestigial-sideband; (iii) A method for simultaneous chromatic and polarization-mode dispersions monitoring by adding a frequency-shifted carrier; (iv) Polarization-insensitive optical parametric amplification by depolarizing the pump; (v) All optical chromatic dispersion monitoring potential for ultra-high speed (>40 Gbit/s) optical systems using cross-phase modulation in a highly nonlinear fiber; (vi) A novel fiber-based autocorrelator using polarimetric four-wave mixing effect and a tunable differential-group-delay element; (vii) A simple all-fiber-based autocorrelator by measuring the degree-of-polarization; and (viii) Reduction of pattern dependent data distortion in a stimulated Brillouin scattering based slow light element. These techniques will play key roles in future high-speed dynamic WDM optical

  7. A Fiber-Optic Borehole Seismic Vector Sensor System for Geothermal Site Characterization and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Paulsson, Bjorn N.P. [Paulsson, Inc.; Thornburg, Jon A [Paulsson, Inc.; He, Ruiqing [Paulsson, Inc.

    2015-04-21

    Seismic techniques are the dominant geophysical techniques for the characterization of subsurface structures and stratigraphy. The seismic techniques also dominate the monitoring and mapping of reservoir injection and production processes. Borehole seismology, of all the seismic techniques, despite its current shortcomings, has been shown to provide the highest resolution characterization and most precise monitoring results because it generates higher signal to noise ratio and higher frequency data than surface seismic techniques. The operational environments for borehole seismic instruments are however much more demanding than for surface seismic instruments making both the instruments and the installation much more expensive. The current state-of-the-art borehole seismic instruments have not been robust enough for long term monitoring compounding the problems with expensive instruments and installations. Furthermore, they have also not been able to record the large bandwidth data available in boreholes or having the sensitivity allowing them to record small high frequency micro seismic events with high vector fidelity. To reliably achieve high resolution characterization and long term monitoring of Enhanced Geothermal Systems (EGS) sites a new generation of borehole seismic instruments must therefore be developed and deployed. To address the critical site characterization and monitoring needs for EGS programs, US Department of Energy (DOE) funded Paulsson, Inc. in 2010 to develop a fiber optic based ultra-large bandwidth clamped borehole seismic vector array capable of deploying up to one thousand 3C sensor pods suitable for deployment into ultra-high temperature and high pressure boreholes. Tests of the fiber optic seismic vector sensors developed on the DOE funding have shown that the new borehole seismic sensor technology is capable of generating outstanding high vector fidelity data with extremely large bandwidth: 0.01 – 6,000 Hz. Field tests have shown

  8. Requirements for Bend Insensitive Fiber in Millimeter-Wave Fronthaul Systems

    DEFF Research Database (Denmark)

    Rommel, Simon; Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José;

    2015-01-01

    The impact of fiber bending on mm-wave radioover-fiber transmission is investigated and the need for bend insensitive fiber for front-haul installation confirmed. A 70m Wband hybrid photonic-wireless link including bend insensitive fiber is demonstrated with BER

  9. Scanning electron microscopy of collagen fiber orientation in the bone lamellar system in non-decalcified human samples.

    Science.gov (United States)

    Pannarale, L; Braidotti, P; d'Alba, L; Gaudio, E

    1994-01-01

    Previous studies on collagen fiber orientation have led to different interpretations and theories about the fiber arrangement in the lamellar compact bone. The purpose of this investigation was to provide new and more in-depth data on fiber arrangement in the lamellar bone system in order to explain the orientation of the fiber bundles. This was carried out by applying a simple method of preparation which permitted observation of non-decalcified samples. A previously isolated Haversian system was subjected to slow bending up to reaching the fracture point. Hence, the fracture surface was observed by SEM. The same samples were also observed by polarized light microscopy. A significant alternation of fiber orientation in the adjacent lamellae was observed. Different domains of differently oriented fibers were present within the same lamella; conjugating fibers connecting adjacent lamellae were also shown. This method avoided most of the artifacts due to chemical treatment of bone samples. The results can be easily interpreted by means of the same criteria applied in mechanics for the studying of composite materials.

  10. Design of an all-fiber erbium-doped laser system for simulating power load in backbone networks

    Science.gov (United States)

    Pobořil, Radek; Bednárek, Lukáš; Vanderka, Aleš; Hájek, Lukáš; Zbořil, Ondřej; Vašinek, Vladimír

    2016-12-01

    This article is focused on the design of an all-fiber laser that was supposed to be used for simulating power load similar to the power load in backbone networks. The first part of the article is a brief introduction to the topic of lasers and erbium doped fiber amplifiers. The following parts present design of a fiber laser with ring cavity, and measuring the ideal length of a doped fiber and the split ratio of the output coupler. After proposing the first stage -a laser- we focused on the construction of the two following stages -EDFA preamplifier and EDFA amplifier. There were used fibers with various levels of erbium ion density, namely ISO-GAIN I6, and Liekki ER110-4/125. The resulting output power of the whole system was 320 mW. This value is sufficient when we take into account that we used only single-mode fibers with energy pumped directly to the fiber core. The output wavelength of the whole laser system was 1559 nm.

  11. High power fiber lasers

    Institute of Scientific and Technical Information of China (English)

    LOU Qi-hong; ZHOU Jun

    2007-01-01

    In this review article, the development of the double cladding optical fiber for high power fiber lasers is reviewed. The main technology for high power fiber lasers, including laser diode beam shaping, fiber laser pumping techniques, and amplification systems, are discussed in de-tail. 1050 W CW output and 133 W pulsed output are ob-tained in Shanghai Institute of Optics and Fine Mechanics, China. Finally, the applications of fiber lasers in industry are also reviewed.

  12. Electrospun fibers as potential carrier systems for enhanced drug release of perphenazine.

    Science.gov (United States)

    Bruni, Giovanna; Maggi, Lauretta; Tammaro, Loredana; Lorenzo, Rosadele Di; Friuli, Valeria; D'Aniello, Sharon; Maietta, Mariarosa; Berbenni, Vittorio; Milanese, Chiara; Girella, Alessandro; Marini, Amedeo

    2016-09-10

    Solubility represents an important challenge for formulation of drugs, because the therapeutic efficacy of a drug depends on the bioavailability and ultimately on its solubility. Low aqueous solubility is one of the main issues related with formulation design and development of new molecules. Many drug molecules present bioavailability problems due to their poor solubility. For this reason there is a great interest in the development of new carrier systems able to enhance the dissolution of poorly water-soluble drugs. In this work, fibers containing an insoluble model drug and prepared by an electrospinning method, are proposed and evaluated to solve this problem. Two hydrophilic polymers, polyvinylpyrrolidone (Plasdone® K29/32) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) were used to increase the water solubility of perphenazine. The physico-chemical characterization suggests that the drug loaded in the fibers is in the amorphous state. Both polymeric carriers are effective to promote the drug dissolution rate in water, where this active pharmaceutical ingredient is insoluble, due to the fine dispersion of the drug into the polymeric matrices, obtained with this production technique. In fact, the dissolution profiles of the fibers, compared to the simple physical mixture of the two components, and to the reference commercial product Trilafon® 8mg tablets, show that a strong enhancement of the drug dissolution rate can be achieved with the electrospinning technique.

  13. Hollow-Fiber Cartridges: Model Systems for Virus Removal from Blood

    Science.gov (United States)

    Jacobitz, Frank; Menon, Jeevan

    2005-11-01

    Aethlon Medical is developing a hollow-fiber hemodialysis device designed to remove viruses and toxins from blood. Possible target viruses include HIV and pox-viruses. The filter could reduce virus and viral toxin concentration in the patient's blood, delaying illness so the patient's immune system can fight off the virus. In order to optimize the design of such a filter, the fluid mechanics of the device is both modeled analytically and investigated experimentally. The flow configuration of the proposed device is that of Starling flow. Polysulfone hollow-fiber dialysis cartridges were used. The cartridges are charged with water as a model fluid for blood and fluorescent latex beads are used in the experiments as a model for viruses. In the experiments, properties of the flow through the cartridge are determined through pressure and volume flow rate measurements of water. The removal of latex beads, which are captured in the porous walls of the fibers, was measured spectrophotometrically. Experimentally derived coefficients derived from these experiments are used in the analytical model of the flow and removal predictions from the model are compared to those obtained from the experiments.

  14. Self-monitoring fiber reinforced polymer strengthening system for civil engineering infrastructures

    Science.gov (United States)

    Jiang, Guoliang; Dawood, Mina; Peters, Kara; Rizkalla, Sami

    2008-03-01

    Fiber reinforced polymer (FRP) materials are currently used for strengthening civil engineering infrastructures. The strengthening system is dependant on the bond characteristics of the FRP to the external surface of the structure to be effective in resisting the applied loads. This paper presents an innovative self-monitoring FRP strengthening system. The system consists of two components which can be embedded in FRP materials to monitor the global and local behavior of the strengthened structure respectively. The first component of the system is designed to evaluate the applied load acting on a structure based on elongation of the FRP layer along the entire span of the structure. Success of the global system has been demonstrated using a full-scale prestressed concrete bridge girder which was loaded up to failure. The test results indicate that this type of sensor can be used to accurately determine the load prior to failure within 15 percent of the measured value. The second sensor component consists of fiber Bragg grating sensors. The sensors were used to monitor the behavior of steel double-lap shear splices tested under tensile loading up to failure. The measurements were used to identify abnormal structural behavior such as epoxy cracking and FRP debonding. Test results were also compared to numerical values obtained from a three dimensional shear-lag model which was developed to predict the sensor response.

  15. Overlap and Nonoverlap Between the ICF Core Sets for Hearing Loss and Otology and Audiology Intake Documentation.

    Science.gov (United States)

    van Leeuwen, Lisette M; Merkus, Paul; Pronk, Marieke; van der Torn, Marein; Maré, Marcel; Goverts, S Theo; Kramer, Sophia E

    Factors). One extra ICF category emerged from the intake documentation that is currently not included in the Core Sets: sleep functions. Various Personal Factors emerged from the intake documentation that are currently not defined in the ICF classification. The results showed substantial overlap between the ICF Core Sets for HL and the intake documentation of otology and audiology, but also revealed areas of nonoverlap. These findings contribute to the evaluation of the content validity of the Core Sets. The overlap can be viewed as supportive of the Core Sets' content validity. The nonoverlap in Core Sets categories indicates that current Dutch intake procedures may not cover all aspects relevant to patients with ear/hearing problems. The identification of extra constructs suggests that the Core Sets may not include all areas of functioning that are relevant to Dutch Otology and Audiology patients. Consideration of incorporating both aspects into future intake practice deserves attention. Operationalization of the ICF Core Sets categories, including the extra constructs identified in this study, into a practical and integral intake instrument seems an important next step.

  16. Improving the power efficiency of SOA-based UWB over fiber systems via pulse shape randomization

    Science.gov (United States)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2016-09-01

    A simple pulse shape randomization scheme is considered in this paper for improving the performance of ultra wide band (UWB) communication systems using On Off Keying (OOK) or pulse position modulation (PPM) formats. The advantage of the proposed scheme, which can be either employed for impulse radio (IR) or for carrier-based systems, is first theoretically studied based on closed-form derivations of power spectral densities. Then, we investigate an application to an IR-UWB over optical fiber system, by utilizing the 4th and 5th orders of Gaussian derivatives. Our approach proves to be effective for 1 Gbps-PPM and 2 Gbps-OOK transmissions, with an advantage in terms of power efficiency for short distances. We also examine the performance for a system employing an in-line Semiconductor Optical Amplifier (SOA) with the view to achieve a reach extension, while limiting the cost and system complexity.

  17. 无交叠垂直梳齿平动微镜的驱动特性%Driving characteristics of non-overlap vertical electrostatic combdriver for optical translational micromirror

    Institute of Scientific and Technical Information of China (English)

    翟雷应; 徐静; 钟少龙; 吴亚明

    2012-01-01

    To design a non-overlap vertical electrostatic combdriver for the optical translational micromirror of ..an optical phase modulator, a mathematic model based on the conformal mapping was built to research the driving performance of the combdriver in detail. According to the theory of complex variable function, an analytical model was established for the electrostatic field of comb actuator by conformal mapping. Then, the electrostatic force in a certain displacement range was deduced by the analytical model for researching the movable comb finger. The results were compared with the corresponding resolution by the Finite Element Method (FEM). Finally, a non-overlap vertical combdriver was successfully fabricated by Micro Electronic Mechanic System(MEMS) process, and an optical Michelson interference system was constructed to measure the static driving charateristics of thecomb driver. The result shows that the displacement of proposed non-overlap vertical electrostatic combdriver is 325 nm (phase difference 2-n) with a dc driving voltage of 28 V and the offset vertical comb actuator can be actuated to 2. 07 pm under a dc driving voltage of 90 V. The measured results accord excellently with the simulated results using the conformal mapping and FEM method, which proves proposed analytical model to be correct. It can provide theoretical and pratical bases for design of non-overlap vertical electrostatic combdrivers.%为了设计用于光相位调制器平动微镜的无交叠梳齿驱动器,建立了保角变换数学模型,研究了驱动器的驱动特性.从复变函数理论出发,建立了驱动器的保角变换静电场解析模型;以动齿受力为研究对象,根据不同情形下的动齿受力特点,求解了一定区间内动齿的静电力并与有限元模拟计算结果进行了对比分析.采用微机电系统(MEMS)工艺制作出了无交叠梳齿驱动器,搭建了Michelson干涉仪光学测试系统,测试了无交叠梳齿驱动器的静态驱

  18. Numerical study of point spread function of a fast neutron radiography system based on scintillating-fiber array

    Institute of Scientific and Technical Information of China (English)

    ZHANG; FaQiang

    2007-01-01

    For a scintillating-fiber array fast-neutron radiography system, a point-spread- function computing model was introduced, and the simulation code was developed. The results of calculation show that fast-neutron radiographs vary with the size of fast neutron sources, the size of fiber cross-section and the imaging geometry. The results suggest that the following qualifications are helpful for a good point spread function: The cross-section of scintillating fibers not greater than 200μm×200μm, the size of neutron source as small as a few millimeters, the distance between the source and the scintillating fiber array greater than 1 m, and inspected samples placed as close as possible to the array. The results give suggestions not only to experiment considerations but also to the estimation of spatial resolution for a specific system.……

  19. Optimizing high-power Yb-doped fiber amplifier systems in the presence of transverse mode instabilities.

    Science.gov (United States)

    Jauregui, Cesar; Otto, Hans-Jürgen; Breitkopf, Sven; Limpert, J; Tünnermann, A

    2016-04-18

    The average output power of Yb-doped fiber amplifier systems is currently limited by the onset of transverse mode instabilities. Besides, it has been recently shown that the transverse mode instability threshold can be significantly reduced by the presence of photodarkening in the fiber. Therefore, reducing the photodarkening level of the core material composition is the most straightforward way to increase the output average power of fiber amplifier systems but, unfortunately, this is not always easy or possible. In this paper we present guidelines to optimize the output average power of fiber amplifiers affected by transverse mode instabilities and photodarkening. The guidelines derived from the simulations do not involve changes in the composition of the active material (except for its doping concentration), but can still lead to a significant increase of the transverse mode instability threshold. The dependence of this parameter on the active ion concentration and the core conformation, among others, will be studied and discussed.

  20. Numerical study of point spread function of a fast neutron radiography system based on scintillating-fiber array

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ For a scintillating-fiber array fast-neutron radiography system, a point-spread- function computing model was introduced, and the simulation code was developed. The results of calculation show that fast-neutron radiographs vary with the size of fast neutron sources, the size of fiber cross-section and the imaging geometry. The results suggest that the following qualifications are helpful for a good point spread function: The cross-section of scintillating fibers not greater than 200μm×200μm, the size of neutron source as small as a few millimeters, the distance between the source and the scintillating fiber array greater than 1 m, and inspected samples placed as close as possible to the array. The results give suggestions not only to experiment considerations but also to the estimation of spatial resolution for a specific system.

  1. A strict error bound with separated contributions of the discretization and of the iterative solver in non-overlapping domain decomposition methods

    CERN Document Server

    Rey, Valentine; Gosselet, Pierre

    2013-01-01

    This paper deals with the estimation of the distance between the solution of a static linear mechanic problem and its approximation by the finite element method solved with a non-overlapping domain decomposition method (FETI or BDD). We propose a new strict upper bound of the error which separates the contribution of the iterative solver and the contribution of the discretization. Numerical assessments show that the bound is sharp and enables us to define an objective stopping criterion for the iterative solver

  2. A Non-Invasive Multichannel Hybrid Fiber-Optic Sensor System for Vital Sign Monitoring

    Directory of Open Access Journals (Sweden)

    Marcel Fajkus

    2017-01-01

    Full Text Available In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber-optic sensor system for basic vital sign monitoring. This sensor uses a novel non-invasive measurement probe based on the fiber Bragg grating (FBG. The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS. The PDMS is non-reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long-term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person's chest using a real-time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field.

  3. A Non-Invasive Multichannel Hybrid Fiber-Optic Sensor System for Vital Sign Monitoring

    Science.gov (United States)

    Fajkus, Marcel; Nedoma, Jan; Martinek, Radek; Vasinek, Vladimir; Nazeran, Homer; Siska, Petr

    2017-01-01

    In this article, we briefly describe the design, construction, and functional verification of a hybrid multichannel fiber-optic sensor system for basic vital sign monitoring. This sensor uses a novel non-invasive measurement probe based on the fiber Bragg grating (FBG). The probe is composed of two FBGs encapsulated inside a polydimethylsiloxane polymer (PDMS). The PDMS is non-reactive to human skin and resistant to electromagnetic waves, UV absorption, and radiation. We emphasize the construction of the probe to be specifically used for basic vital sign monitoring such as body temperature, respiratory rate and heart rate. The proposed sensor system can continuously process incoming signals from up to 128 individuals. We first present the overall design of this novel multichannel sensor and then elaborate on how it has the potential to simplify vital sign monitoring and consequently improve the comfort level of patients in long-term health care facilities, hospitals and clinics. The reference ECG signal was acquired with the use of standard gel electrodes fixed to the monitored person’s chest using a real-time monitoring system for ECG signals with virtual instrumentation. The outcomes of these experiments have unambiguously proved the functionality of the sensor system and will be used to inform our future research in this fast developing and emerging field. PMID:28075341

  4. Submarine Optical Fiber Cable Systems for High Speed Growth Developments in Optical Communication Networks

    Directory of Open Access Journals (Sweden)

    Ahmed Nabih Zaki Rashed

    2012-07-01

    Full Text Available Optical Submarine Cable systems play a principal role in international telecommunications, thanks to their superiority over satellite systems in terms of stability, latency and upgradability. The business of constructing and then maintaining and selling capacity over submarine fiber optic cables is fascinating, and is absolutely fundamental to modern day communications. The sector has its own unique challenges due to the extraordinarily rapid pace of development in transmission technologies as well as the timescales and levels of investment required to build new systems. In the present paper, ultimate optical transmission of ultra multi channels huge submarine cables under different depth conditions has been investigated over wide range of the affecting parameters. The double impact of both temperature and pressure is also analyzed. We have employed multiplexing technique namely UW-WDM to be merged number of 10000 transmitted channels on the same submarine optical transmission links respectively. Based on experimental data, both the deep ocean water temperature and pressure are tailored as functions of the water depth. The product of the transmitted bit rate and the repeater spacing is processed over wide ranges of the affecting parameters. As well as we have taken into account the estimation of the total cost planning and transmission data rate capacity of the submarine fiber cable system for this multiplexing technique under study.

  5. A Full-Duplex Radio-over-Fiber System Based on Frequency Twelvefold

    Institute of Scientific and Technical Information of China (English)

    ZHU Jia-Hu; HUANG Xu-Guang; TAO Jin; XIE Jin-Ling

    2011-01-01

    A full-duplex radio-over-fiber system using frequency-twelvefold optical millimeter-wave based on external modulation via a Mach-Zehnder modulator is proposed and analyzed theoretically. The simulation results show that the power penalties for both the downstream and upstream signals are less than 0.5 dB. In this scheme, the configuration of a base station is simplified without laser, while the frequency of local oscillator signal is largely reduced due to the frequency-twelvefold millimeter-wave technique. The cost of the new system is largely reduced.%@@ A full-duplex radio-over-fiber system using frequency-twelvefold optical millimeter-wave based on external modulation via a Mach-Zehnder modulator is proposed and analyzed theoretically.The simulation results show that the power penalties for both the downstream and upstream signals are iess than 0.5 dB.In this scheme, the configuration of a base station is simplified without laser, while the frequency of local oscillator signal is largely reduced due to the frequency-twelvefold millimeter-wave technique.The cost of the new system is largely reduced.

  6. Channel Measurements for a Optical Fiber-Wireless Transmission System in the 75-110 GHz Band

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Yu, Xianbin; Zhao, Ying;

    2011-01-01

    We report on measured optical fiber W-band wireless channel characteristics such as frequency response, channel loss and fading, directivity, channel capacity and phase noise. Our proposed system performs a sextuple frequency up-conversion after 20 km of fiber transmission, followed by a W......-band wireless link. Our experimental measurements are intended to provide engineering rules for designing hybrid multi-gigabit W band transmission links....

  7. High Pressure Sensing and Dynamics Using High Speed Fiber Bragg Grating Interrogation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, G. [LANL; Sandberg, R. L. [LANL; Lalone, B. M. [NSTec; Marshall, B. R. [NSTec; Grover, M. [NSTec; Stevens, G. D. [NSTec; Udd, E. [Columbia Gorge Research

    2014-06-01

    Fiber Bragg gratings (FBGs) are developing into useful sensing tools for measuring high pressure dynamics in extreme environments under shock loading conditions. Approaches using traditional diode array coupled FBG interrogation systems are often limited to readout speeds in the sub-MHz range. For shock wave physics, required detection speeds approaching 100 MHz are desired. We explore the use of two types of FBG sensing systems that are aimed at applying this technology as embedded high pressure probes for transient shock events. Both approaches measure time resolved spectral shifts in the return light from short (few mm long) uniform FBGs at 1550 nm. In the first approach, we use a fiber coupled spectrometer to demultiplex spectral channels into an array (up to 12) of single element InGaAs photoreceivers. By monitoring the detectors during a shock impact event with high speed recording, we are able to track the pressure induced spectral shifting in FBG down to a time resolution of 20 ns. In the second approach, developed at the Special Technologies Lab, a coherent mode-locked fiber laser is used to illuminate the FBG sensor. After the sensor, wavelength-to-time mapping is accomplished with a chromatic dispersive element, and entire spectra are sampled using a single detector at the modelocked laser repetition rate of 50 MHz. By sampling with a 12 GHz InGaAs detector, direct wavelength mapping in time is recorded, and the pressure induced FBG spectral shift is sampled at 50 MHz. Here, the sensing systems are used to monitor the spectral shifts of FBGs that are immersed into liquid water and shock compressed using explosives. In this configuration, the gratings survive to pressures approaching 50 kbar. We describe both approaches and present the measured spectral shifts from the shock experiments.

  8. Zigbee networking technology and its application in Lamost optical fiber positioning and control system

    Science.gov (United States)

    Jin, Yi; Zhai, Chao; Gu, Yonggang; Zhou, Zengxiang; Gai, Xiaofeng

    2010-07-01

    4,000 fiber positioning units need to be positioned precisely in LAMOST(Large Sky Area Multi-object Optical Spectroscopic Telescope) optical fiber positioning & control system, and every fiber positioning unit needs two stepper motors for its driven, so 8,000 stepper motors need to be controlled in the entire system. Wireless communication mode is adopted to save the installing space on the back of the focal panel, and can save more than 95% external wires compared to the traditional cable control mode. This paper studies how to use the ZigBee technology to group these 8000 nodes, explores the pros and cons of star network and tree network in order to search the stars quickly and efficiently. ZigBee technology is a short distance, low-complexity, low power, low data rate, low-cost two-way wireless communication technology based on the IEEE 802.15.4 protocol. It based on standard Open Systems Interconnection (OSI): The 802.15.4 standard specifies the lower protocol layers-the physical layer (PHY), and the media access control (MAC). ZigBee Alliance defined on this basis, the rest layers such as the network layer and application layer, and is responsible for high-level applications, testing and marketing. The network layer used here, based on ad hoc network protocols, includes the following functions: construction and maintenance of the topological structure, nomenclature and associated businesses which involves addressing, routing and security and a self-organizing-self-maintenance functions which will minimize consumer spending and maintenance costs. In this paper, freescale's 802.15.4 protocol was used to configure the network layer. A star network and a tree network topology is realized, which can build network, maintenance network and create a routing function automatically. A concise tree network address allocate algorithm is present to assign the network ID automatically.

  9. RCLED Optimization and Nonlinearity Compensation in a Polymer Optical Fiber DMT System

    Directory of Open Access Journals (Sweden)

    Pu Miao

    2016-09-01

    Full Text Available In polymer optical fiber (POF systems, the nonlinear transfer function of the resonant cavity light emitting diode (RCLED drastically degrades the communication performance. After investigating the characteristics of the RCLED nonlinear behavior, an improved digital look-up-table (LUT pre-distorter, based on an adaptive iterative algorithm, is proposed. Additionally, the system parameters, including the bias current, the average electrical power, the LUT size and the step factor are also jointly optimized to achieve a trade-off between the system linearity, reliability and the computational complexity. With the proposed methodology, both the operating point and efficiency of RCLED are enhanced. Moreover, in the practical 50 m POF communication system with the discrete multi-tone (DMT modulation, the bit error rate performance is improved by over 12 dB when RCLED is operating in the nonlinear region. Therefore, the proposed pre-distorter can both resist the nonlinearity and improve the operating point of RCLED.

  10. Development of a low-cost and miniaturized fiber Bragg grating strain sensor system

    Science.gov (United States)

    Yuan, Lili; Zhao, Yao; Sato, Shinya

    2017-05-01

    A fiber Bragg grating (FBG) strain sensor system that measures strains from reflected power changes of FBGs is presented. A laser diode used as a light source and a power meter are used in the system, which makes the FBG sensor system inexpensive and miniaturized. The reflected power of an FBG is expressed by the product of the reflectivity of the FBG and the optical power of the laser diode. Comparison of the strain applied in the experiment with that calculated from the reflected power shows that relative errors are within 5.1%, which verifies the feasibility of the strain sensor system proposed in this work. In addition, on the basis of this method, we fabricate a cantilever load cell using an FBG as the strain gauge instead of an electrical resistance, and also quantify the load range that can be measured by this load cell.

  11. Fiber-optic interferometric two-dimensional scattering-measurement system.

    Science.gov (United States)

    Zhu, Yizheng; Giacomelli, Michael G; Wax, Adam

    2010-05-15

    We present a fiber-optic interferometric system for measuring depth-resolved scattering in two angular dimensions using Fourier-domain low-coherence interferometry. The system is a unique hybrid of the Michelson and Sagnac interferometer topologies. The collection arm of the interferometer is scanned in two dimensions to detect angular scattering from the sample, which can then be analyzed to determine the structure of the scatterers. A key feature of the system is the full control of polarization of both the illumination and the collection fields, allowing for polarization-sensitive detection, which is essential for two-dimensional angular measurements. System performance is demonstrated using a double-layer microsphere phantom. Experimental data from samples with different sizes and acquired with different polarizations show excellent agreement with Mie theory, producing structural measurements with subwavelength accuracy.

  12. Simplified radio-over-fiber transport systems with a low-cost multiband light source.

    Science.gov (United States)

    Chang, Ching-Hung; Peng, Peng-Chun; Lu, Hai-Han; Shih, Chine-Liang; Chen, Hwan-Wen

    2010-12-01

    In this Letter, low-cost radio-over-fiber (ROF) transport systems are proposed and experimentally demonstrated. By utilizing a laser diode (LD) and a local oscillator (LO) to generate coherent multiband optical carriers, as well as a self-composed wavelength selector to separate every two carriers for different ROF transport systems, no any other dedicated LD or electrical frequency upconverting circuit/process is needed in the central station (CS). Compared with current ROF systems, the required numbers of LDs, LOs, and mixers in a CS are significantly reduced. Reducing the number of components not only can simplify the network structure but can also reduce the volume and complexity of the relative logistics. To demonstrate the practice of the proposed ROF transport systems, clear eye diagrams and error-free transmission performance are experimentally presented.

  13. A rotating inertial navigation system with the rotating axis error compensation consisting of fiber optic gyros

    Institute of Scientific and Technical Information of China (English)

    ZHA Feng; HU Bai-qing; QIN Fang-jun; LUO Yin-bo

    2012-01-01

    An effective and flexible rotation and compensation scheme is designed to improve the accuracy of rotating inertial navigation system (RINS).The accuracy of single-axial RINS is limited by the errors on the rotating axis.A novel inertial measurement unit (IMU) scheme with error compensation for the rotating axis of fiber optic gyros (FOG) RINS is presented.In the scheme,two couples of inertial sensors with similar error characteristics are mounted oppositely on the rotating axes to compensate the sensors error.Without any change for the rotation cycle,this scheme improves the system's precision and reliability,and also offers the redundancy for the system.The results of 36 h navigation simulation prove that the accuracy of the system is improved notably compared with normal strapdown INS,besides the heading accuracy is increased by 3 times compared with single-axial RINS,and the position accuracy is improved by 1 order of magnitude.

  14. A Novel Temperature-Compensated, Intensity-Modulated Fiber Bragg Grating Sensor System

    Institute of Scientific and Technical Information of China (English)

    Xin-Yong Dong; Hwa-Yaw Tam

    2008-01-01

    An intensity-modulated, fiber Bragg grating (FBG) sensor system based on radio-frequency (RF) signal measurement is presented. The RF signal is generated at a photodetector by two modulated optical signals reflected from the sensing FBG and a reference one. Bragg wavelength shift of the sensing FBG changes intensity of the RF signal by changing phase difference between the two optical signals, with temperature effect being compensated automatically by the reference FBG. Strain measurement with a maximum sensitivity of -0.34 μV/με has been achieved.

  15. Agreement between fiber optic and optoelectronic systems for quantifying sagittal plane spinal curvature in sitting.

    Science.gov (United States)

    Cloud, Beth A; Zhao, Kristin D; Breighner, Ryan; Giambini, Hugo; An, Kai-Nan

    2014-07-01

    Spinal posture affects how individuals function from a manual wheelchair. There is a need to directly quantify spinal posture in this population to ultimately improve function. A fiber optic system, comprised of an attached series of sensors, is promising for measuring large regions of the spine in individuals sitting in a wheelchair. The purpose of this study was to determine the agreement between fiber optic and optoelectronic systems for measuring spinal curvature, and describe the range of sagittal plane spinal curvatures in natural sitting. Able-bodied adults (n = 26, 13 male) participated. Each participant assumed three sitting postures: natural, slouched (accentuated kyphosis), and extension (accentuated lordosis) sitting. Fiber optic (ShapeTape) and optoelectronic (Optotrak) systems were applied to the skin over spinous processes from S1 to C7 and used to measure sagittal plane spinal curvature. Regions of kyphosis and lordosis were identified. A Cobb angle-like method was used to quantify lordosis and kyphosis. Generalized linear model and Bland-Altman analyses were used to assess agreement. A strong correlation exists between curvature values obtained with Optotrak and ShapeTape (R(2) = 0.98). The mean difference between Optotrak and ShapeTape for kyphosis in natural, extension, and slouched postures was 4.30° (95% LOA: -3.43 to 12.04°), 3.64° (95% LOA: -1.07 to 8.36°), and 4.02° (95% LOA: -2.80 to 10.84°), respectively. The mean difference for lordosis, when present, in natural and extension postures was 2.86° (95% LOA: -1.18 to 6.90°) and 2.55° (95% LOA: -3.38 to 8.48°), respectively. In natural sitting, the mean ± SD of kyphosis values was 35.07 ± 6.75°. Lordosis was detected in 8/26 participants: 11.72 ± 7.32°. The fiber optic and optoelectronic systems demonstrate acceptable agreement for measuring sagittal plane thoracolumbar spinal curvature.

  16. CATV/radio-on-fiber transport system based on direct modulation

    Science.gov (United States)

    Tzeng, Shah-Jye

    2006-03-01

    A directly modulated CATV/radio-on-fiber (ROF) transport system based on external light injection technique, optical single sideband (SSB) filter, and RF amplifier predistorter is proposed and demonstrated. To the best of my knowledge, it is the first time to transmit CATV and ROF signals simultaneously in a directly modulated form. Good performances of carrier-to-noise ratio (CNR), composite second order (CSO) and composite triple beat (CTB) were obtained for CATV band; and low third order intermodulation distortion to carrier ratio (IMD3/C), and bit error rate (BER) values were achieved for ROF application.

  17. Thulium-doped fiber chirped-pulse amplification system with 2 GW of peak power.

    Science.gov (United States)

    Gaida, C; Gebhardt, M; Stutzki, F; Jauregui, C; Limpert, J; Tünnermann, A

    2016-09-01

    Thulium-doped fibers with ultra large mode-field areas offer new opportunities for the power scaling of mid-IR ultrashort-pulse laser sources. Here, we present a laser system delivering a pulse-peak power of 2 GW and a nearly transform-limited pulse duration of 200 fs in combination with 28.7 W of average power. This performance level has been achieved by optimizing the pulse shape, reducing the overlap with atmospheric absorption lines, and incorporating a climate chamber to reduce the humidity of the atmospheric environment.

  18. Quantum key distribution system in standard telecommunications fiber using a short wavelength single-photon source

    CERN Document Server

    Collins, R J; Fernandez, V; Gordon, K J; Makhonin, M N; Timpson, J A; Tahraoui, A; Hopkinson, M; Fox, A M; Skolnick, M S; Buller, G S; 10.1063/1.3327427

    2010-01-01

    A demonstration of the principles of quantum key distribution is performed using a single-photon source in a proof of concept test-bed over a distance of 2 km in standard telecommunications optical fiber. The single-photon source was an optically-pumped quantum dot in a microcavity emitting at a wavelength of 895 nm. Characterization of the quantum key distribution parameters was performed at a range of different optical excitation powers. An investigation of the effect of varying the optical excitation power of the quantum dot microcavity on the quantum bit error rate and cryptographic key exchange rate of the system are presented.

  19. Remote atom entanglement in a fiber-connected three-atom system

    OpenAIRE

    Yan-Qing, Guo; Jing, Chen; He-Shan, Song

    2008-01-01

    An Ising-type atom-atom interaction is obtained in a fiber-connected three-atom system. The interaction is effective when $\\Delta\\approx \\gamma _{0}\\gg g$. The preparations of remote two-atom and three-atom entanglement governed by this interaction are discussed in specific parameters region. The overall two-atom entanglement is very small because of the existence of the third atom. However, the three-atom entanglement can reach a maximum very close to 1.

  20. Agreement between Fiber Optic and Optoelectronic Systems for Quantifying Sagittal Plane Spinal Curvature in Sitting

    Science.gov (United States)

    Cloud, Beth A.; Zhao, Kristin D.; Breighner, Ryan; Giambini, Hugo; An, Kai-Nan

    2014-01-01

    Spinal posture affects how individuals function from a manual wheelchair. There is a need to directly quantify spinal posture in this population to ultimately improve function. A fiber optic system, comprised of an attached series of sensors, is promising for measuring large regions of the spine in individuals sitting in a wheelchair. The purpose of this study was to determine the agreement between fiber optic and optoelectronic systems for measuring spinal curvature, and describe the range of sagittal plane spinal curvatures in natural sitting. Able-bodied adults (n=26, 13 male) participated. Each participant assumed three sitting postures: natural, slouched (accentuated kyphosis), and extension (accentuated lordosis) sitting. Fiber optic (ShapeTape) and optoelectronic (Optotrak) systems were applied to the skin over spinous processes from S1 to C7 and used to measure sagittal plane spinal curvature. Regions of kyphosis and lordosis were identified. A Cobb angle-like method was used to quantify lordosis and kyphosis. Generalized linear model and Bland-Altman analyses were used to assess agreement. A strong correlation exists between curvature values obtained with Optotrak and ShapeTape (R2=0.98). The mean difference between Optotrak and ShapeTape for kyphosis in natural, extension, and slouched postures was 4.30° (95%LOA: −3.43-12.04°), 3.64° (95%LOA: −1.07-8.36°), and 4.02° (95%LOA: −2.80-10.84°), respectively. The mean difference for lordosis, when present, in natural and extension postures is 2.86° (95%LOA: −1.18-6.90°) and 2.55° (95%LOA: −3.38-8.48°), respectively. In natural sitting, the mean±SD of kyphosis values was 35.07± 6.75°. Lordosis was detected in 8/26 participants: 11.72±7.32°. The fiber optic and optoelectronic systems demonstrate acceptable agreement for measuring sagittal plane thoracolumbar spinal curvature. PMID:24909579

  1. A fiber-optic strain measurement and quench localization system for use in superconducting accelerator dipole magnets

    NARCIS (Netherlands)

    Oort, van Johannes M.; Scanlan, Ronald M.; Kate, ten Herman H.J.

    1995-01-01

    A novel fiber-optic measurement system for superconducting accelerator magnets is described. The principal component is an extrinsic Fabry-Perot interferometer to determine localized strain and stress in coil windings. The system can be used either as a sensitive relative strain measurement system o

  2. Study of EDFA and Raman system transmission reach with 256 Gb/s PM-16QAM signals over three optical fibers with 100 km spans.

    Science.gov (United States)

    Downie, John D; Hurley, Jason; Pikula, Dragan; Ten, Sergey; Towery, Chris

    2013-07-15

    We compare the transmission performance of three different optical fibers in separate 256 Gb/s PM-16QAM systems amplified with erbium doped fiber amplifiers (EDFAs) and distributed Raman amplification. The span length in each system is 100 km. The fibers studied include standard single-mode fiber, single-mode fiber with ultra-low loss, and ultra-low loss fiber with large effective area. We find that the single-mode fiber with ultra-low loss and the large effective area fiber with ultra-low loss afford reach advantages of up to about 31% and 80%, respectively, over standard fiber measured at distances with 3 dB margin over the forward error correction (FEC) threshold. The Raman amplified systems provide about 50% reach length enhancement over the EDFA systems for all three fibers in the experimental set-up. For the best performing fiber with large effective area and ultra-low loss, the absolute reach lengths with 3 dB margin are greater than 1140 km and 1700 km for the for EDFA and Raman systems, respectively.

  3. The MaNGA integral field unit fiber feed system for the Sloan 2.5 m telescope

    Energy Technology Data Exchange (ETDEWEB)

    Drory, N. [McDonald Observatory, The University of Texas at Austin, 1 University Station, Austin, TX 78712 (United States); MacDonald, N.; Byler, N. [Department of Astronomy, University of Washington, Box 351580 Seattle, WA 98195 (United States); Bershady, M. A.; Smith, M.; Tremonti, C. A.; Wake, D. A.; Eigenbrot, A.; Jaehnig, K. [Department of Astronomy, University of Wisconsin, 475 N. Charter St., Madison, WI 53706 (United States); Bundy, K. [Kavli Institute for the Physics and Mathematics of The Universe (Kavli IPMU, WPI), Todai Institutes for Advanced Study, The University of Tokyo, Kashiwa, Japan 277-8583 (Japan); Gunn, J. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Law, D. R.; Cherinka, B. [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, 50 St. George St, Toronto, ON M5S 3H4 (Canada); Stoll, R. [C Technologies, Inc., 757 Route 202/206, Bridgewater, NJ 08807 (United States); Yan, R. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky, 40506-0055 (United States); Weijmans, A. M. [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Cope, F.; Holder, D.; Huehnerhoff, J. [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Harding, P., E-mail: drory@astro.as.utexas.edu [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); and others

    2015-02-01

    We describe the design, manufacture, and performance of bare-fiber integral field units (IFUs) for the SDSS-IV survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) on the the Sloan 2.5 m telescope at Apache Point Observatory. MaNGA is a luminosity-selected integral-field spectroscopic survey of 10{sup 4} local galaxies covering 360–1030 nm at R∼2200. The IFUs have hexagonal dense packing of fibers with packing regularity of 3 μm (rms), and throughput of 96 ± 0.5% from 350 nm to 1 μm in the lab. Their sizes range from 19 to 127 fibers (3–7 hexagonal layers) using Polymicro FBP 120:132:150 μm core:clad:buffer fibers to reach a fill fraction of 56%. High throughput (and low focal-ratio degradation (FRD)) is achieved by maintaining the fiber cladding and buffer intact, ensuring excellent surface polish, and applying a multi-layer anti-reflection (AR) coating of the input and output surfaces. In operations on-sky, the IFUs show only an additional 2.3% FRD-related variability in throughput despite repeated mechanical stressing during plate plugging (however other losses are present). The IFUs achieve on-sky throughput 5% above the single-fiber feeds used in SDSS-III/BOSS, attributable to equivalent performance compared to single fibers and additional gains from the AR coating. The manufacturing process is geared toward mass-production of high-multiplex systems. The low-stress process involves a precision ferrule with a hexagonal inner shape designed to lead inserted fibers to settle in a dense hexagonal pattern. The ferrule ID is tapered at progressively shallower angles toward its tip and the final 2 mm are straight and only a few microns larger than necessary to hold the desired number of fibers. Our IFU manufacturing process scales easily to accommodate other fiber sizes and can produce IFUs with substantially larger fiber counts. To assure quality, automated testing in a simple and inexpensive system enables complete characterization of

  4. The MaNGA Integral Field Unit Fiber Feed System for the Sloan 2.5 m Telescope

    Science.gov (United States)

    Drory, N.; MacDonald, N.; Bershady, M. A.; Bundy, K.; Gunn, J.; Law, D. R.; Smith, M.; Stoll, R.; Tremonti, C. A.; Wake, D. A.; Yan, R.; Weijmans, A. M.; Byler, N.; Cherinka, B.; Cope, F.; Eigenbrot, A.; Harding, P.; Holder, D.; Huehnerhoff, J.; Jaehnig, K.; Jansen, T. C.; Klaene, M.; Paat, A. M.; Percival, J.; Sayres, C.

    2015-02-01

    We describe the design, manufacture, and performance of bare-fiber integral field units (IFUs) for the SDSS-IV survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) on the the Sloan 2.5 m telescope at Apache Point Observatory. MaNGA is a luminosity-selected integral-field spectroscopic survey of 104 local galaxies covering 360-1030 nm at R˜ 2200. The IFUs have hexagonal dense packing of fibers with packing regularity of 3 μm (rms), and throughput of 96 ± 0.5% from 350 nm to 1 μm in the lab. Their sizes range from 19 to 127 fibers (3-7 hexagonal layers) using Polymicro FBP 120:132:150 μm core:clad:buffer fibers to reach a fill fraction of 56%. High throughput (and low focal-ratio degradation (FRD)) is achieved by maintaining the fiber cladding and buffer intact, ensuring excellent surface polish, and applying a multi-layer anti-reflection (AR) coating of the input and output surfaces. In operations on-sky, the IFUs show only an additional 2.3% FRD-related variability in throughput despite repeated mechanical stressing during plate plugging (however other losses are present). The IFUs achieve on-sky throughput 5% above the single-fiber feeds used in SDSS-III/BOSS, attributable to equivalent performance compared to single fibers and additional gains from the AR coating. The manufacturing process is geared toward mass-production of high-multiplex systems. The low-stress process involves a precision ferrule with a hexagonal inner shape designed to lead inserted fibers to settle in a dense hexagonal pattern. The ferrule ID is tapered at progressively shallower angles toward its tip and the final 2 mm are straight and only a few microns larger than necessary to hold the desired number of fibers. Our IFU manufacturing process scales easily to accommodate other fiber sizes and can produce IFUs with substantially larger fiber counts. To assure quality, automated testing in a simple and inexpensive system enables complete characterization of throughput and

  5. A map of brain neuropils and fiber systems in the ant Cardiocondyla obscurior

    Directory of Open Access Journals (Sweden)

    Joris eBressan

    2015-02-01

    Full Text Available A wide spectrum of occupied ecological niches and spectacular morphological adaptations make social insects a prime object for comparative neuroanatomical studies. Eusocial insects have evolved complex societies based on caste polyphenism. A diverse behavioral repertoire of morphologically distinct castes of the same species requires a high degree of plasticity in the central nervous system. We have analyzed the central brain neuropils and fiber tract systems of the worker of the ant Cardiocondyla obscurior, a model for the study of social traits. Our analysis is based on whole mount preparations of adult brains labeled with an antibody against Drosophila-Synapsin, which cross-reacts strongly with synapses in Cardiocondyla. Neuropil compartments stand out as domains with a certain texture and intensity of the anti-Synapsin signal. By contrast, fiber tracts, which are composed of bundles of axons accompanied by glia and are devoid of synapses, appear as channels or sheaths with low anti-Synapsin signal. We have generated a digital 3D atlas of the Cardiocondyla brain neuropil. The atlas provides a reference for future studies of brain polymorphisms in distinct castes, brain development or localization of neurotransmitter systems.

  6. Multiplexed Optical Fiber Sensors for Coal Fired Advanced Fossil Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Anbo [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Pickrell, Gary [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2012-03-31

    This report summarizes technical progress on the program Multiplexed Optical Fiber Sensors for Coal Fired Advanced Fossil Energy Systems funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed jointly by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering and the Department of Materials Science and Engineering at Virginia Tech. This three-year project started on October 1, 2008. In the project, a fiber optical sensing system based on intrinsic Fabry-Perot Interferometer (IFPI) was developed for strain and temperature measurements for Ultra Supercritical boiler condition assessment. Investigations were focused on sensor design, fabrication, attachment techniques and novel materials for high temperature and strain measurements. At the start of the project, the technical requirements for the sensing technology were determined together with our industrial partner Alstom Power. As is demonstrated in Chapter 4, all the technical requirements are successfully met. The success of the technology extended beyond laboratory test; its capability was further validated through the field test at DOE NETL, in which the sensors yielded distributed temperature mapping of a testing coupon installed in the turbine test rig. The measurement results agreed well with prior results generated with thermocouples. In this project, significant improvements were made to the IFPI sensor technology by splicing condition optimization, transmission loss reduction, sensor signal demodulation and sensor system design.

  7. Development of an in situ fiber optic Raman system to monitor hydrothermal vents.

    Science.gov (United States)

    Battaglia, Tina M; Dunn, Eileen E; Lilley, Marvin D; Holloway, John; Dable, Brian K; Marquardt, Brian J; Booksh, Karl S

    2004-07-01

    The development of a field portable fiber optic Raman system modified from commercially available components that can operate remotely on battery power and withstand the corrosive environment of the hydrothermal vents is discussed. The Raman system is designed for continuous monitoring in the deep-sea environment. A 785 nm diode laser was used in conjunction with a sapphire ball fiber optic Raman probe, single board computer, and a CCD detector. Using the system at ambient conditions the detection limits of SO(4)(2-), CO(3)(2-) and NO(3)(-) were determined to be approximately 0.11, 0.36 and 0.12 g l(-1) respectively. Mimicking the cold conditions of the sea floor by placing the equipment in a refrigerator yielded slightly worse detection limits of approximately 0.16 g l(-1) for SO(4)(-2) and 0.20 g l(-1) for NO(3)(-). Addition of minerals commonly found in vent fluid plumes also decreased the detection limits to approximately 0.33 and 0.34 g l(-1) respectively for SO(4)(-2) and NO(3)(-).

  8. High power fiber laser system for a high repetition rate laserwire

    Directory of Open Access Journals (Sweden)

    L. J. Nevay

    2014-07-01

    Full Text Available We present the development of a high power fiber laser system to investigate its suitability for use in a transverse electron beam profile monitor, i.e., a laserwire. A system capable of producing individual pulses up to 165.8±0.4  μJ at 1036 nm with a full width at half maximum of 1.92±0.12  ps at 6.49 MHz is demonstrated using a master oscillator power amplifier design with a final amplification stage in a rod-type photonic crystal fiber. The pulses are produced in trains of 1 ms in a novel burst mode amplification scheme to match the bunch pattern of the charged particles in an accelerator. This method allows pulse energies up to an order of magnitude greater than the steady-state value of 17.0±0.6  μJ to be achieved at the beginning of the burst with a demonstrated peak power of 25.8±1.7  MW after compression. The system is also shown to demonstrate excellent spatial quality with an M^{2}=1.26±0.01 in both dimensions, which would allow nearly diffraction limited focusing to be achieved.

  9. Simulation research of location mechanism of chaotic distributed optical fiber sensing system

    Science.gov (United States)

    Guo, Sujie; Fang, Nian; Wang, Lutang; Huang, Zhaoming

    2016-01-01

    A distributed optical fiber sensing system based on a bidirectional chaotic fiber ring laser has been proposed. The output waveforms induced by an external disturbance in some period are different from those in other time. This period equals the time difference between two counter-propagating beams arriving at the semiconductor optical amplifier (SOA) from the disturbance point. It is utilized for the disturbance location. In this paper, the location mechanism is explored by investigating optical interaction in the SOA in two simulation systems with a continuous wave optical source. One system is for studying the interaction of a continuous wave beam and a phase modulation beam input into the SOA from the left and right sides respectively. The other system is for investigating the interaction of two phase modulation beams counter-arriving at the SOA with a certain time difference. Under a small SOA current, only the transformation of the phase modulation to intensity modulation occurs due to the interference caused by facets reflection of the SOA. With the increase of current, the cross-gain modulation effect of the SOA makes the interference signal in one beam copy to the other one reversely in the phase, which generates the time difference characteristic. For the chaotic sensing system the situation is similar to the large current case in the second simulation system, only the conversion of the modulation format is achieved by the sensitivity to initial values of chaotic systems. The cross-gain modulation effect in the SOA contributes to the time difference location method.

  10. Fiber Bragg Grating Sensor System for Monitoring Smart Composite Aerospace Structures

    Science.gov (United States)

    Moslehi, Behzad; Black, Richard J.; Gowayed, Yasser

    2012-01-01

    Lightweight, electromagnetic interference (EMI) immune, fiber-optic, sensor- based structural health monitoring (SHM) will play an increasing role in aerospace structures ranging from aircraft wings to jet engine vanes. Fiber Bragg Grating (FBG) sensors for SHM include advanced signal processing, system and damage identification, and location and quantification algorithms. Potentially, the solution could be developed into an autonomous onboard system to inspect and perform non-destructive evaluation and SHM. A novel method has been developed to massively multiplex FBG sensors, supported by a parallel processing interrogator, which enables high sampling rates combined with highly distributed sensing (up to 96 sensors per system). The interrogation system comprises several subsystems. A broadband optical source subsystem (BOSS) and routing and interface module (RIM) send light from the interrogation system to a composite embedded FBG sensor matrix, which returns measurand-dependent wavelengths back to the interrogation system for measurement with subpicometer resolution. In particular, the returned wavelengths are channeled by the RIM to a photonic signal processing subsystem based on powerful optical chips, then passed through an optoelectronic interface to an analog post-detection electronics subsystem, digital post-detection electronics subsystem, and finally via a data interface to a computer. A range of composite structures has been fabricated with FBGs embedded. Stress tensile, bending, and dynamic strain tests were performed. The experimental work proved that the FBG sensors have a good level of accuracy in measuring the static response of the tested composite coupons (down to submicrostrain levels), the capability to detect and monitor dynamic loads, and the ability to detect defects in composites by a variety of methods including monitoring the decay time under different dynamic loading conditions. In addition to quasi-static and dynamic load monitoring, the

  11. Research on the surveillance technology and the comprehensive management network system using the optical fiber about a road management system

    Science.gov (United States)

    Nakano, Masahiro; Okuno, Masatomi; Sasaki, Susumu; Yano, Koji

    2005-05-01

    In recent years, IT (Information Technology) has been utilized in various fields of civil engineering. Especially, trials have been made to utilize optical fibers as sensors to measure strain of civil engineering structures, ground deformation, temperature, etc., and they have been installed for measuring in road structures and civil engineering structures including tunnel, river, and cut-slope structures. In order to make such optical monitoring systems of civil engineering structures more general and organic systems, it would be effective to combine them with such comprehensive systems as ITS. We investigate checking systems utilizing GIS technology, etc. that can process and analyze an enormous amount of data in real time and also investigate the construction of general monitoring systems of road facilities which can perform thorough management from monitoring to maintenance utilizing information technology networks.

  12. Label free imaging system for measuring blood flow speeds using a single multi-mode optical fiber (Conference Presentation)

    Science.gov (United States)

    Sigal, Iliya; Caravaca Aguirre, Antonio M.; Gad, Raanan; Piestun, Rafael; Levi, Ofer

    2016-03-01

    We demonstrate a single multi-mode fiber-based micro-endoscope for measuring blood flow speeds. We use the transmission-matrix wavefront shaping approach to calibrate the multi-mode fiber and raster-scan a focal spot across the distal fiber facet, imaging the cross-polarized back-reflected light at the proximal facet using a camera. This setup allows assessment of the backscattered photon statistics: by computing the mean speckle contrast values across the proximal fiber facet we show that spatially-resolved flow speed maps can be inferred by selecting an appropriate camera integration time. The proposed system is promising for minimally-invasive studies of neurovascular coupling in deep brain structures.

  13. High average power and energy microsecond pulse generation from an erbium-doped fluoride fiber MOPA system.

    Science.gov (United States)

    Luo, Hongyu; Li, Jianfneg; Xie, Jitao; Zhai, Bo; Wei, Chen; Liu, Yong

    2016-12-12

    We reported a high average power and energy microsecond pulse erbium-doped fluoride fiber MOPA system centered at 2786.8 nm. The master oscillator was a passively Q-switched erbium-doped fluoride fiber laser based on SESAM in a linear cavity. Then a one-stage erbium-doped fluoride fiber amplifier was used to boost its average output power to 4.2 W and pulse energy to 58.87 μJ. The pulse duration and repetition rate were 2.29 µs and 71.73 kHz, respectively. To the best of our knowledge, the achieved average output power and pulse energy are the recorded levels for the passively Q-switched fiber lasers at 3 μm wavelength region.

  14. Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Pickrell, Gary [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States); Scott, Brian [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

    2014-06-30

    This report covers the technical progress on the program “Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems”, funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Materials Science & Engineering and Electrical & Computer Engineering Departments at Virginia Tech, and summarizes technical progress from July 1st, 2005 –June 30th, 2014. The objective of this program was to develop novel fiber materials for high temperature gas sensors based on evanescent wave absorption in optical fibers. This project focused on two primary areas: the study of a sapphire photonic crystal fiber (SPCF) for operation at high temperature and long wavelengths, and a porous glass based fiber optic sensor for gas detection. The sapphire component of the project focused on the development of a sapphire photonic crystal fiber, modeling of the new structures, fabrication of the optimal structure, development of a long wavelength interrogation system, testing of the optical properties, and gas and temperature testing of the final sensor. The fabrication of the 6 rod SPCF gap bundle (diameter of 70μm) with a hollow core was successfully constructed with lead-in and lead-out 50μm diameter fiber along with transmission and gas detection testing. Testing of the sapphire photonic crystal fiber sensor capabilities with the developed long wavelength optical system showed the ability to detect CO2 at or below 1000ppm at temperatures up to 1000°C. Work on the porous glass sensor focused on the development of a porous clad solid core optical fiber, a hollow core waveguide, gas detection capabilities at room and high temperature, simultaneous gas species detection, suitable joining technologies for the lead-in and lead-out fibers and the porous sensor, sensor system sensitivity improvement, signal processing improvement, relationship between pore structure and fiber

  15. Fiber Optics Technology.

    Science.gov (United States)

    Burns, William E.

    1986-01-01

    Discusses various applications of fiber optics technology: information systems, industrial robots, medicine, television, transportation, and training. Types of jobs that will be available with fiber optics training (such as electricians and telephone cable installers and splicers) are examined. (CT)

  16. Fiber optic video monitoring system for remote CT/MR scanners clinically accepted

    Science.gov (United States)

    Tecotzky, Raymond H.; Bazzill, Todd M.; Eldredge, Sandra L.; Tagawa, James; Sayre, James W.

    1992-07-01

    With the proliferation of CT travel to distant scanners to review images before their patients can be released. We designed a fiber-optic broadband video system to transmit images from seven scanner consoles to fourteen remote monitoring stations in real time. This system has been used clinically by radiologists for over one years. We designed and conducted a user survey to categorize the levels of system use by section (Chest, GI, GU, Bone, Neuro, Peds, etc.), to measure operational utilization and acceptance of the system into the clinical environment, to clarify the system''s importance as a clinical tool for saving radiologists travel-time to distant CT the system''s performance and limitations as a diagnostic tool. The study was administered directly to radiologists using a printed survey form. The results of the survey''s compiled data show a high percentage of system usage by a wide spectrum of radiologists. Clearly, this system has been accepted into the clinical environment as a highly valued diagnostic tool in terms of time savings and functional flexibility.

  17. Axon Termination, Pruning, and Synaptogenesis in the Giant Fiber System of Drosophila melanogaster Is Promoted by Highwire.

    Science.gov (United States)

    Borgen, Melissa; Rowland, Kimberly; Boerner, Jana; Lloyd, Brandon; Khan, Aruna; Murphey, Rodney

    2017-03-01

    The ubiquitin ligase Highwire has a conserved role in synapse formation. Here, we show that Highwire coordinates several facets of central synapse formation in the Drosophila melanogaster giant fiber system, including axon termination, axon pruning, and synaptic function. Despite the similarities to the fly neuromuscular junction, the role of Highwire and the underlying signaling pathways are distinct in the fly's giant fiber system. During development, branching of the giant fiber presynaptic terminal occurs and, normally, the transient branches are pruned away. However, in highwire mutants these ectopic branches persist, indicating that Highwire promotes axon pruning. highwire mutants also exhibit defects in synaptic function. Highwire promotes axon pruning and synaptic function cell-autonomously by attenuating a mitogen-activated protein kinase pathway including Wallenda, c-Jun N-terminal kinase/Basket, and the transcription factor Jun. We also show a novel role for Highwire in non-cell autonomous promotion of synaptic function from the midline glia. Highwire also regulates axon termination in the giant fibers, as highwire mutant axons exhibit severe overgrowth beyond the pruning defect. This excessive axon growth is increased by manipulating Fos expression in the cells surrounding the giant fiber terminal, suggesting that Fos regulates a trans-synaptic signal that promotes giant fiber axon growth. Copyright © 2017 by the Genetics Society of America.

  18. Modeling and parametric analysis of hollow fiber membrane system for carbon capture from multicomponent flue gas

    KAUST Repository

    Khalilpour, Rajab

    2011-08-12

    The modeling and optimal design/operation of gas membranes for postcombustion carbon capture (PCC) is presented. A systematic methodology is presented for analysis of membrane systems considering multicomponent flue gas with CO 2 as target component. Simplifying assumptions is avoided by namely multicomponent flue gas represented by CO 2/N 2 binary mixture or considering the co/countercurrent flow pattern of hollow-fiber membrane system as mixed flow. Optimal regions of flue gas pressures and membrane area were found within which a technoeconomical process system design could be carried out. High selectivity was found to not necessarily have notable impact on PCC membrane performance, rather, a medium selectivity combined with medium or high permeance could be more advantageous. © 2011 American Institute of Chemical Engineers (AIChE).

  19. Cost-effective bidirectional digitized radio-over-fiber systems employing sigma delta modulation

    Science.gov (United States)

    Lee, Kyung Woon; Jung, HyunDo; Park, Jung Ho

    2016-11-01

    We propose a cost effective digitized radio-over-fiber (D-RoF) system employing a sigma delta modulation (SDM) and a bidirectional transmission technique using phase modulated downlink and intensity modulated uplink. SDM is transparent to different radio access technologies and modulation formats, and more suitable for a downlink of wireless system because a digital to analog converter (DAC) can be avoided at the base station (BS). Also, Central station and BS share the same light source by using a phase modulation for the downlink and an intensity modulation for the uplink transmission. Avoiding DACs and light sources have advantages in terms of cost reduction, power consumption, and compatibility with conventional wireless network structure. We have designed a cost effective bidirectional D-RoF system using a low pass SDM and measured the downlink and uplink transmission performance in terms of error vector magnitude, signal spectra, and constellations, which are based on the 10MHz LTE 64-QAM standard.

  20. Development of a fiber optic health monitoring system for aerospace applications

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper describes our research activity involved in the identification, development and test of a prototype SHM system constituted by optical sensing nodes to measure both temperature and strain on ultra high temperature ceramics (UHTC) materials up to 1000 ℃. Commercially available optic devices can operate up to 550 ℃. To raise temperature limit up to 1000 ℃, custom devices, mainly under development for scientific applications, have been identified. A prototype SHM system has been developed adopting a FBG sensor for temperature measurement and an EFPI sensor in sapphire fiber for strain measurement. The preliminary findings from thermo-mechanical tests indicate that former SHM system is capable of accurately measuring strain at elevated temperatures on UHTC materials.

  1. Monitoring of Thermal Protection Systems Using Robust Self-Organizing Optical Fiber Sensing Networks

    Science.gov (United States)

    Richards, Lance

    2013-01-01

    The general aim of this work is to develop and demonstrate a prototype structural health monitoring system for thermal protection systems that incorporates piezoelectric acoustic emission (AE) sensors to detect the occurrence and location of damaging impacts, and an optical fiber Bragg grating (FBG) sensor network to evaluate the effect of detected damage on the thermal conductivity of the TPS material. Following detection of an impact, the TPS would be exposed to a heat source, possibly the sun, and the temperature distribution on the inner surface in the vicinity of the impact measured by the FBG network. A similar procedure could also be carried out as a screening test immediately prior to re-entry. The implications of any detected anomalies in the measured temperature distribution will be evaluated for their significance in relation to the performance of the TPS during re-entry. Such a robust TPS health monitoring system would ensure overall crew safety throughout the mission, especially during reentry

  2. System simulation method for fiber-based homodyne multiple target interferometers using short coherence length laser sources

    Science.gov (United States)

    Fox, Maik; Beuth, Thorsten; Streck, Andreas; Stork, Wilhelm

    2015-09-01

    Homodyne laser interferometers for velocimetry are well-known optical systems used in many applications. While the detector power output signal of such a system, using a long coherence length laser and a single target, is easily modelled using the Doppler shift, scenarios with a short coherence length source, e.g. an unstabilized semiconductor laser, and multiple weak targets demand a more elaborated approach for simulation. Especially when using fiber components, the actual setup is an important factor for system performance as effects like return losses and multiple way propagation have to be taken into account. If the power received from the targets is in the same region as stray light created in the fiber setup, a complete system simulation becomes a necessity. In previous work, a phasor based signal simulation approach for interferometers based on short coherence length laser sources has been evaluated. To facilitate the use of the signal simulation, a fiber component ray tracer has since been developed that allows the creation of input files for the signal simulation environment. The software uses object oriented MATLAB code, simplifying the entry of different fiber setups and the extension of the ray tracer. Thus, a seamless way from a system description based on arbitrarily interconnected fiber components to a signal simulation for different target scenarios has been established. The ray tracer and signal simulation are being used for the evaluation of interferometer concepts incorporating delay lines to compensate for short coherence length.

  3. Laser linewidth and fiber nonlinearity tolerance study of C-16QAM compared to square 16QAM in coherent OFDM system

    Science.gov (United States)

    Xu, Fei; Qiao, Yaojun; Zhou, Ji; Guo, Mengqi; Tian, Huiping

    2017-03-01

    We introduced an effective modulation format circle 16 quadrature amplitude modulation (C-16QAM) to improve the laser linewidth induced phase noise and fiber nonlinear effects tolerance in coherent orthogonal frequency division multiplexing (OFDM) system without other losses compared to square 16QAM. Although C-16QAM has improved the performance of single channel system with Viterbi-Viterbi carrier phase estimation, C-16QAM using in coherent OFDM system has not been performed and such configuration of system may solve many problems in the next generation access networks. Here we numerically studied two separate manifestations of phase noise generated by laser linewidth and fiber nonlinear effects. We take these two kinds of phase noise into consideration separately by investigating the influence of laser linewidth with fixed launch power into transmission fiber and the influence of fiber nonlinear effects with fixed laser linewidth. We find that the C-16QAM improves the laser linewidth induced phase noise significantly and improves fiber nonlinear effects tolerance to a certain degree compared to square 16QAM. This coherent C-16QAM OFDM system may have great prospects for the next generation access networks for these significantly improvements.

  4. Low-cost bidirectional hybrid fiber-visible laser light communication system based on carrier-less amplitude phase modulation

    Science.gov (United States)

    He, Jing; Dong, Huan; Deng, Rui; Chen, Lin

    2016-08-01

    We propose a bidirectional hybrid fiber-visible laser light communication (fiber-VLC) system. To reduce the cost of the system, the cheap and easy integration red vertical cavity surface emitting lasers, low-complexity carrier-less amplitude phase modulation format, and wavelength reuse technique are utilized. Meanwhile, the automatic gain control amplifier voltage and bias voltage for downlink and uplink are optimized. The simulation results show that, by using the proposed system, the bit error rate of 3.8×10-3 can be achieved for 16-Gbps CAP signal after 30-km standard single mode fiber and 8-m VLC bidirectional transmission. Therefore, it indicates the feasibility and potential of proposed system for indoor access network.

  5. The Performance and Fouling Control of Submerged Hollow Fiber (HF Systems: A Review

    Directory of Open Access Journals (Sweden)

    Ebrahim Akhondi

    2017-07-01

    Full Text Available The submerged membrane filtration concept is well-established for low-pressure microfiltration (MF and ultrafiltration (UF applications in the water industry, and has become a mainstream technology for surface-water treatment, pretreatment prior to reverse osmosis (RO, and membrane bioreactors (MBRs. Compared to submerged flat sheet (FS membranes, submerged hollow fiber (HF membranes are more common due to their advantages of higher packing density, the ability to induce movement by mechanisms such as bubbling, and the feasibility of backwashing. In view of the importance of submerged HF processes, this review aims to provide a comprehensive landscape of the current state-of-the-art systems, to serve as a guide for further improvements in submerged HF membranes and their applications. The topics covered include recent developments in submerged hollow fiber membrane systems, the challenges and developments in fouling-control methods, and treatment protocols for membrane permeability recovery. The highlighted research opportunities include optimizing the various means to manipulate the hydrodynamics for fouling mitigation, developing online monitoring devices, and extending the submerged HF concept beyond filtration.

  6. Illumination performance and energy saving of a solar fiber optic lighting system.

    Science.gov (United States)

    Lingfors, David; Volotinen, Tarja

    2013-07-01

    The illumination performance and energy savings of a solar fiber optic lighting system have been verified in a study hall--corridor interior. The system provides intensive white light with a high luminous flux of 4500 lm under 130000 lx direct sun radiation at a 10 m fiber distance from the sun-tracking light collector. The color temperature that describes the light color perceived is 5800 ± 300 K, i.e. close to the direct sunlight outside, and the color rendering index (86), that describes how well colors are rendered under the light source, is higher for the solar lights than for the supplementary fluorescent lights (77). Thus this high quality solar lighting improves the visibility of all kinds of objects compared to the fluorescent lights. Annual lighting energy savings of 19% in Uppsala, Sweden and 46% in southern Europe were estimated for a study hall interior, as well as 27% and 55% respectively in an interior illuminated 16 h per day all days of a year.

  7. Effect of denitrifying bacteria on the electrochemical reaction of activated carbon fiber in electrochemical biofilm system

    Institute of Scientific and Technical Information of China (English)

    YING Diwen; JIA Jinping; ZHANG Lehua

    2007-01-01

    An electrochemical-activated denitrifying biofilm system consisting of activated carbon fiber electrodes immobilized with denitrifying bacteria film as cathode was studied.A revised model for an electrochemical-activated denitrifying biofilm was developed and validated by electrochemical analysis of cathodal polarization curves and nitrate consumption rate.The cathodal polarization curve and nitrate consumption rate were introduced to verify the rate of electrochemical reaction and the activity of denitrifying bacteria,respectively.It was shown that the denitrification process effectively strengthened the electrochemical reaction while the electron also intensified denitrification activity.Electron was transferred between electrochemical process and biological process not only by hydrogen molecule but also by new produced active hydrogen atom.Additionally,a parameter of apparent exchange current density was deprived from the cathodal polarization curve with high overpotential,and a new bio-effect current density was defined through statistical analysis,which was linearly dependent to the activity of denitrification bacteria.Activated carbon fiber (ACF) electrode was also found to be more suitable to the electrochemical denitrifying system compared with graphite and platinum.

  8. High Power Spark Delivery System Using Hollow Core Kagome Lattice Fibers

    Directory of Open Access Journals (Sweden)

    Ciprian Dumitrache

    2014-08-01

    Full Text Available This study examines the use of the recently developed hollow core kagome lattice fibers for delivery of high power laser pulses. Compared to other photonic crystal fibers (PCFs, the hollow core kagome fibers have larger core diameter (~50 µm, which allows for higher energy coupling in the fiber while also maintaining high beam quality at the output (M2 = 1.25. We have conducted a study of the maximum deliverable energy versus laser pulse duration using a Nd:YAG laser at 1064 nm. Pulse energies as high as 30 mJ were transmitted for 30 ns pulse durations. This represents, to our knowledge; the highest laser pulse energy delivered using PCFs. Two fiber damage mechanisms were identified as damage at the fiber input and damage within the bulk of the fiber. Finally, we have demonstrated fiber delivered laser ignition on a single-cylinder gasoline direct injection engine.

  9. Fully coherent spectral broadening of femtosecond pulses from an Er:fiber system

    Directory of Open Access Journals (Sweden)

    Brida D.

    2013-03-01

    Full Text Available Coherence properties of the ultrabroadband output from a highly nonlinear germanosilicate fiber pumped by a femtosecond Er:fiber source are investigated. Conditions necessary to achieve full spectral coherence are demonstrated experimentally and analyzed theoretically.

  10. Efficient Tm-Fiber-Pumped Ho:YLF Laser System for Coherent LIDAR Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to employ a recently developed, efficient, high-power, heavily-doped Tm:silica-fiber technology as a high-gain fiber pre-amplifier and as a...

  11. MR tractography; Visualization of structure of nerve fiber system from diffusion weighted images with maximum intensity projection method

    Energy Technology Data Exchange (ETDEWEB)

    Kinosada, Yasutomi; Okuda, Yasuyuki (Mie Univ., Tsu (Japan). School of Medicine); Ono, Mototsugu (and others)

    1993-02-01

    We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology. (author).

  12. Results of monitoring large carbon fiber post-tensioning systems in a balanced Cantilever Brdige (Dintelharbour Bridge, The Netherlands)

    NARCIS (Netherlands)

    Vervuurt, A.H.J.M.; Kaptijn, N.; Hageman, J.G.; Kuilboer, C.P.M.

    2012-01-01

    Steel post-tensioning systems and stay cables are susceptible to corrosion. Carbon fiber systems are not. However, there was no experience on the long term behavior of such post-tensioned elements. Four external tendons (75 m long), stressed to a load of 2650 kN, were applied in a large balanced can

  13. Results of monitoring large carbon fiber post-tensioning systems in a balanced Cantilever Brdige (Dintelharbour Bridge, The Netherlands)

    NARCIS (Netherlands)

    Vervuurt, A.H.J.M.; Kaptijn, N.; Hageman, J.G.; Kuilboer, C.P.M.

    2012-01-01

    Steel post-tensioning systems and stay cables are susceptible to corrosion. Carbon fiber systems are not. However, there was no experience on the long term behavior of such post-tensioned elements. Four external tendons (75 m long), stressed to a load of 2650 kN, were applied in a large balanced

  14. An efficient low-noise single-frequency 1033 nm Yb3+-doped MOPA phosphate fiber laser system

    Science.gov (United States)

    Deng, Huaqiu; Chen, Dan; Zhao, Qilai; Yang, Changsheng; Zhang, Yuanfei; Zhang, Yuning; Feng, Zhouming; Yang, Zhongmin; Xu, Shanhui

    2017-06-01

    An efficient low-noise, single-frequency 1033 nm master oscillator power amplifier (MOPA) Yb3+-doped phosphate fiber (YPF) laser system is demonstrated. A maximal output power of 612 mW with a laser linewidth of 65 dB and relative intensity noise (RIN) of laser system has applications in the fields of optical frequency standards and beam combining.

  15. Study on weigh-in-motion system based on chirped fiber gratings

    Science.gov (United States)

    Zhang, Dong-sheng; Guo, Dan; Li, Wei; Li, Yong-guo; Wu, An; Yao, Kai-fang; Jiang, De-sheng

    2007-11-01

    A novel weigh-in-motion (WIM) system used for high way is developed based on Chirped fiber Bragg gratings (CFBG) in this paper. The WIM system consists of four CFBG pressure sensors, each of which contains a couple of CFBG. The sensor can directly output optical intensity signal, so the postprocessor instrument is simple and cheap instead of expensive wavelength demodulation apparatus. Theoretical and experimental results indicate that output optical intensity of the sensor is linearly proportional to the pressure, and the linearity and the repeated error can respectively reach to 0.9997 and 0.05%FS. We have also exceeded series experiments with several kinds of automobile with different velocity, and received good results of relative error below 5%.

  16. PERFORMANCE IMPROVEMENT FOR A WCDMA RADIO OVER FIBER SYSTEM USING DIGITAL PRE-DISTORTER

    Institute of Scientific and Technical Information of China (English)

    Ying Xiangyue; Xu Tiefeng; Liu Taijun; Nie Qiuhua

    2012-01-01

    In this paper,a Radio Over Fiber (ROF) system with a Digital Pre-Distorter (DPD) for WCDMA signal transmission is investigated.A Look-Up Table (LUT) based DPD and a Memory Polynomial (MP) DPD are applied in the ROF link so as to suppress the out-of-band spurious spectrum and improve the transmission performance.The experimental results show that the out-of-band emission due to existence of the third-order Inter-Modulation Distortion (IMD3) is obviously suppressed by these two DPD.An Adjacent Channel Power Ratio (ACPR) improvement of 8 dB is obtained for a single-carrier WCDMA signal transmission.These two DPD have equal ability in linearization of the ROF system for a three-carrier WCDMA signal transmission.There is no apparent memory effects exist in the ROF link.

  17. Fiber-Optic Defect and Damage Locator System for Wind Turbine Blades

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Vahid Sotoudeh; Dr. Richard J. Black; Dr. Behzad Moslehi; Mr. Aleks Plavsic

    2010-10-30

    IFOS in collaboration with Auburn University demonstrated the feasibility of a Fiber Bragg Grating (FBG) integrated sensor system capable of providing real time in-situ defect detection, localization and quantification of damage. In addition, the system is capable of validating wind turbine blade structural models, using recent advances in non-contact, non-destructive dynamic testing of composite structures. This new generation method makes it possible to analyze wind turbine blades not only non-destructively, but also without physically contacting or implanting intrusive electrical elements and transducers into the structure. Phase I successfully demonstrated the feasibility of the technology with the construction of a 1.5 kHz sensor interrogator and preliminary instrumentation and testing of both composite material coupons and a wind turbine blade.

  18. Digital subcarrier multiplexing for fiber nonlinearity mitigation in coherent optical communication systems.

    Science.gov (United States)

    Qiu, Meng; Zhuge, Qunbi; Chagnon, Mathieu; Gao, Yuliang; Xu, Xian; Morsy-Osman, Mohamed; Plant, David V

    2014-07-28

    In this work we experimentally investigate the improved intra-channel fiber nonlinearity tolerance of digital subcarrier multiplexed (SCM) signals in a single-channel coherent optical transmission system. The digital signal processing (DSP) for the generation and reception of the SCM signals is described. We show experimentally that the SCM signal with a nearly-optimum number of subcarriers can extend the maximum reach by 23% in a 24 GBaud DP-QPSK transmission with a BER threshold of 3.8 × 10(-3) and by 8% in a 24 GBaud DP-16-QAM transmission with a BER threshold of 2 × 10(-2). Moreover, we show by simulations that the improved performance of SCM signals is observed over a wide range of baud rates, further indicating the merits of SCM signals in baud-rate flexible agile transmissions and future high-speed optical transport systems.

  19. Pulsed and CW adjustable 1942 nm single-mode all-fiber Tm-doped fiber laser system for surgical laser soft tissue ablation applications.

    Science.gov (United States)

    Huang, Yize; Jivraj, Jamil; Zhou, Jiaqi; Ramjist, Joel; Wong, Ronnie; Gu, Xijia; Yang, Victor X D

    2016-07-25

    A surgical laser soft tissue ablation system based on an adjustable 1942 nm single-mode all-fiber Tm-doped fiber laser operating in pulsed or CW mode with nitrogen assistance is demonstrated. Ex vivo ablation on soft tissue targets such as muscle (chicken breast) and spinal cord (porcine) with intact dura are performed at different ablation conditions to examine the relationship between the system parameters and ablation outcomes. The maximum laser average power is 14.4 W, and its maximum peak power is 133.1 W with 21.3 μJ pulse energy. The maximum CW power density is 2.33 × 106 W/cm2 and the maximum pulsed peak power density is 2.16 × 107 W/cm2. The system parameters examined include the average laser power in CW or pulsed operation mode, gain-switching frequency, total ablation exposure time, and the input gas flow rate. The ablation effects were measured by microscopy and optical coherence tomography (OCT) to evaluate the ablation depth, superficial heat-affected zone diameter (HAZD) and charring diameter (CD). Our results conclude that the system parameters can be tailored to meet different clinical requirements such as ablation for soft tissue cutting or thermal coagulation for future applications of hemostasis.

  20. An Adaptive Damping Network Designed for Strapdown Fiber Optic Gyrocompass System for Ships

    Directory of Open Access Journals (Sweden)

    Jin Sun

    2017-03-01

    Full Text Available The strapdown fiber optic gyrocompass (strapdown FOGC system for ships primarily works on external horizontal damping and undamping statuses. When there are large sea condition changes, the system will switch frequently between the external horizontal damping status and the undamping status. This means that the system is always in an adjustment status and influences the dynamic accuracy of the system. Aiming at the limitations of the conventional damping method, a new design idea is proposed, where the adaptive control method is used to design the horizontal damping network of the strapdown FOGC system. According to the size of acceleration, the parameters of the damping network are changed to make the system error caused by the ship’s maneuvering to a minimum. Furthermore, the jump in damping coefficient was transformed into gradual change to make a smooth system status switch. The adaptive damping network was applied for strapdown FOGC under the static and dynamic condition, and its performance was compared with the conventional damping, and undamping means. Experimental results showed that the adaptive damping network was effective in improving the dynamic performance of the strapdown FOGC.