WorldWideScience

Sample records for fiber optic sensing

  1. Optical fiber rotation sensing

    CERN Document Server

    Burns, William K; Kelley, Paul

    1993-01-01

    Optical Fiber Rotation Sensing is the first book devoted to Interferometric Fiber Optic Gyros (IFOG). This book provides a complete overview of IFOGs, beginning with a historical review of IFOG development and including a fundamental exposition of basic principles, a discussion of devices and components, and concluding with industry reports on state-of-the-art activity. With several chapters contributed by principal developers of this solid-state device, the result is an authoritative work which will serve as the resource for researchers, students, and users of IFOGs.* * State-of-t

  2. Fiber optic sensing and imaging

    CERN Document Server

    2013-01-01

    This book is designed to highlight the basic principles of fiber optic imaging and sensing devices. The editor has organized the book to provide the reader with a solid foundation in fiber optic imaging and sensing devices. It begins with an introductory chapter that starts from Maxwell’s equations and ends with the derivation of the basic optical fiber characteristic equations and solutions (i.e. fiber modes). Chapter 2 reviews most common fiber optic interferometric devices and Chapter 3 discusses the basics of fiber optic imagers with emphasis on fiber optic confocal microscope. The fiber optic interferometric sensors are discussed in detail in chapter 4 and 5. Chapter 6 covers optical coherence tomography and goes into the details of signal processing and systems level approach of the real-time OCT implementation. Also useful forms of device characteristic equations are provided so that this book can be used as a reference for scientists and engineers in the optics and related fields.

  3. 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 ?m, 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.

  4. Optical Fiber Sensing Using Quantum Dots

    Directory of Open Access Journals (Sweden)

    Faramarz Farahi

    2007-12-01

    Full Text Available Recent advances in the application of semiconductor nanocrystals, or quantumdots, as biochemical sensors are reviewed. Quantum dots have unique optical properties thatmake them promising alternatives to traditional dyes in many luminescence basedbioanalytical techniques. An overview of the more relevant progresses in the application ofquantum dots as biochemical probes is addressed. Special focus will be given toconfigurations where the sensing dots are incorporated in solid membranes and immobilizedin optical fibers or planar waveguide platforms.

  5. Fiber optic nanoprobes for biological sensing

    Science.gov (United States)

    Barucci, Andrea; Berneschi, Simone; Cosi, Franco; Nunzi Conti, Gualtiero; Pelli, Stefano; Quercioli, Franco; Soria, Silvia; Righini, Giancarlo C.

    2011-08-01

    Optical sensors have a large impact in the fields of life science research, drug discovery and medical diagnostics. The recent advances in nanotechnology and photonics have led to a new generation of nanotools, capable of probing even the single cell: it has already been demonstrated that nanobiosensors can detect biochemical targets and proteins inside living single cells. Here we provide a brief overview of the field of nanoprobes consisting of tapered, metal-coated optical fibers having nanosize tips, such as those which were originally developed for use in near-field optical microscopy. Moreover we present some preliminary results concerning the characterization of the experimental sensing system which exploits such nanoprobes for intracellular biomedical diagnostics. The feasibility of using the Fluorescence Lifetime Imaging Microscopy (FLIM) technique as a dynamic diagnostics tool with these nanoprobes has been demonstrated.

  6. Fiber-Optic Sensing for In-Space Inspection

    Science.gov (United States)

    Pena, Francisco; Richards, W. Lance; Piazza, Anthony; Parker, Allen R.; Hudson, Larry D.

    2014-01-01

    This presentation provides examples of fiber optic sensing technology development activities performed at NASA Armstrong. Examples of current and previous work that support in-space inspection techniques and methodologies are highlighted.

  7. Sensing characteristics of birefringent microstructured polymer optical fiber

    DEFF Research Database (Denmark)

    Szczurowski, Marcin K.; Frazao, Orlando; Baptista, J. M.; Nielsen, Kristian; Bang, Ole; Urbanczyk, Waclaw

    2011-01-01

    We experimentally studied several sensing characteristics of a birefringent microstructured polymer optical fiber. The fiber exhibits a birefringence of the order 2×10-5 at 1.3 ?m because of two small holes adjacent to the core. In this fiber, we measured spectral dependence of phase and group modal birefringence, bending losses, polarimetric sensitivity to strain and temperature. The sensitivity to strain was also examined for intermodal interference observed in the spectral range below 0.8 ?m....

  8. Fiber Optic Wing Shape Sensing on NASA's Ikhana UAV

    Science.gov (United States)

    Richards, Lance; Parker, Allen R.; Ko, William L.; Piazza, Anthony

    2008-01-01

    This document discusses the development of fiber optic wing shape sensing on NASA's Ikhana vehicle. The Dryden Flight Research Center's Aerostructures Branch initiated fiber-optic instrumentation development efforts in the mid-1990s. Motivated by a failure to control wing dihedral resulting in a mishap with the Helios aircraft, new wing displacement techniques were developed. Research objectives for Ikhana included validating fiber optic sensor measurements and real-time wing shape sensing predictions; the validation of fiber optic mathematical models and design tools; assessing technical viability and, if applicable, developing methodology and approaches to incorporate wing shape measurements within the vehicle flight control system; and, developing and flight validating approaches to perform active wing shape control using conventional control surfaces and active material concepts.

  9. Photoinduced Electron Transfer Based Ion Sensing within an Optical Fiber

    Directory of Open Access Journals (Sweden)

    Tanya M. Monro

    2011-10-01

    Full Text Available We combine suspended-core microstructured optical fibers with the photoinduced electron transfer (PET effect to demonstrate a new type of fluorescent optical fiber-dip sensing platform for small volume ion detection. A sensor design based on a simple model PET-fluoroionophore system and small core microstructured optical fiber capable of detecting sodium ions is demonstrated. The performance of the dip sensor operating in a high sodium concentration regime (925 ppm Na+ and for lower sodium concentration environments (18.4 ppm Na+ is explored and future approaches to improving the sensor’s signal stability, sensitivity and selectivity are discussed.

  10. Optical fiber sensing using quantum dots

    OpenAIRE

    Faramarz Farahi; José Luís Santos; Tito Trindade; Manuel António Martins; Pedro Jorge

    2007-01-01

    Recent advances in the application of semiconductor nanocrystals, or quantum dots, as biochemical sensors are reviewed. Quantum dots have unique optical properties that make them promising alternatives to traditional dyes in many luminescence based bioanalytical techniques. An overview of the more relevant progresses in the application of quantum dots as biochemical probes is addressed. Special focus will be given to configurations where the sensing dots are incorporated in solid membranes an...

  11. Exposed-core chalcogenide microstructured optical fibers for chemical sensing

    Science.gov (United States)

    Troles, Johann; Toupin, Perrine; Brilland, Laurent; Boussard-Plédel, Catherine; Bureau, Bruno; Cui, Shuo; Mechin, David; Adam, Jean-Luc

    2013-05-01

    Chemical bonds of most of the molecules vibrate at a frequency corresponding to the near or mid infrared field. It is thus of a great interest to develop sensitive and portable devices for the detection of specific chemicals and biomolecules for various applications in health, the environment, national security and so on. Optical fibers define practical sensing tools. Chalcogenide glasses are known for their transparency in the infrared optical range and their ability to be drawn as fibers. They are consequently good candidates to be used in biological/chemical sensing. For that matter, in the past decade, chalcogenide glass fibers have been successfully implemented in evanescent wave spectroscopy experiments, for the detection of bio-chemical species in various fields of applications including microbiology and medicine, water pollution and CO2 detection. Different types of fiber can be used: single index fibers or microstructured fibers. Besides, in recent years a new configuration of microstructured fibers has been developed: microstructured exposed-core fibers. This design consists of an optical fiber with a suspended micron-scale core that is partially exposed to the external environment. This configuration has been chosen to elaborate, using the molding method, a chalcogenide fiber for chemical species detection. The sensitivity of this fiber to detect molecules such as propan-2-ol and acetone has been compared with those of single index fibers. Although evanescent wave absorption is inversely proportional to the fiber diameter, the result shows that an exposed-core fiber is much more sensitive than a single index fiber having a twice smaller external diameter.

  12. Fiber optic sensing in rapidly rotating mechanical structures

    Science.gov (United States)

    Zilberman, Shlomi; Berkovic, Garry; Shafir, Ehud; Saadi, Yair; Mazor, Ohad; Goichman, Tal

    2015-11-01

    A novel, generic approach for fiber-optical sensing in rapidly rotating structures is presented. This approach does not require optical ingress via the central rotation axis. In this work, strain sensing at rotation speeds of up to 5000 rpm is demonstrated, and higher speeds should be possible. We demonstrate measurement of the rotation-induced strain in a rotating body at 500 rpm intervals up to 5000 rpm, and results agree very well with predictions.

  13. Neutron-sensing scintillating glass optical fiber detectors

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratory (PNL) has developed and tested the highest-transmission neutron-sensing glass fibers reported in the open literature to date. By developing glass compositions specifically for fiber drawing and by using superior oxidationstate controls and rapid quenching, PNL produces, fiber with useful lengths in excess of 200 cm. These long fibers can be used in detectors. Test results on the fibers used as a form-fitting detector around a small storage container containing neutron and gamma ray sources are reported. Excellent neutron-gamma ray discrimination has been achieved. These neutron-sensing glass optical fibers provide for new methods for monitoring the inventory of, preventing the diversion of, and detecting the unauthorized transport of sensitive nuclear materials. As such, it represents a significant potential element in countering the threat of nuclear terrorism

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

    Energy Technology Data Exchange (ETDEWEB)

    William A. Challener

    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.

  15. Fiber sensing system based on a bragg grating and optical time domain reflectometry

    OpenAIRE

    Chin, Sanghoon; Thévenaz, Luc

    2013-01-01

    Optic fiber sensor characterized in that the sensing fiber is provided with a continuous Bragg grating covering the entire fiber length which is dedicated to sensing and along which spatially resolved measurements are performed.

  16. Recent progress in fiber optic pH sensing

    Science.gov (United States)

    Baldini, Francesco

    1991-03-01

    An analysis of the state of the art in pH sensing by optical fibers is presented. Advantages and drawbacks of this type of measurement are described. Different techniques in the optrode construction are taken into consideration and particular attention is also devoted to the overall optoelectronic system which must satisfy definite market requirements.

  17. Kalman filter for noise removal in optical fiber sensing system

    Science.gov (United States)

    Liu, Tao; Zhang, Wen-ping; Chen, Hui-fang; Feng, Gui-Lan

    2012-10-01

    Noise in the optical fiber sensing system, produced in laser, transmission, demodulation and environment, reduces the Signal-to-Noise Ratio (SNR) and the measuring accuracy of the whole system . In this paper, a statistical approach based on Kalman-filter is undertaken to removal noise of the measured object real time, and then to improve the accuracy of the fiber sensing system. The temperature induced by fiber sensing is modeled as a discrete-time state variable by a Gauss-Markov random process with the Gaussian white and additive noise in the linear dynamic system. Based on Bayesian MAP Inference and minimum mean-square error criterion (MMSE), gain of the kalman-filter and the state error covariance can be regulated by Measurement Update equations to correct posteriori state estimate. Such recursive algorithm can finally get the optimum estimator of the state through time. The performances of the model and the algorithm are investigated in the DOFS temperature sensing system. Variance is used to evaluate its performance in noise removal. At the same time, the experimental results of the method proposed is compared with original measurement data analysis. The algorithm performs more improvement in accuracy of the fiber sensing system, and implements the real-time measurement.

  18. Monitoring of Thermal Protection Systems using Robust Self-Organizing Optical Fiber Sensing Networks Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Objectives a) Development, evaluation and demonstration of a dynamically reconfigurable optical fiber sensing network that is interrogated using the optical...

  19. Extreme temperature sensing using Brillouin scattering in optical fibers

    OpenAIRE

    Fellay, Alexandre

    2003-01-01

    Stimulated Brillouin scattering in silica-based optical fibers may be considered from two different and complementary standpoints. For a physicist, this interaction of light and pressure wave in a material, or equivalently in quantum theory terms between photons and phonons, gives some glimpses of the atomic structure of the solid and of its vibration modes. For an applied engineer, the same phenomenon may be put to good use as a sensing mechanism for distributed measurements, thanks to the d...

  20. New trends and applications of optical fiber sensing technologies at the NEL-FOST

    Science.gov (United States)

    Yang, Minghong; Huang, Chujia; Yuan, Yinquan; Ding, Liyun; Zhou, Ciming

    2015-07-01

    This paper reviews the recent development of optical fiber sensors at the National Engineering Laboratory for Optic Fiber Sensing Technologies (NEL-FOST) at Wuhan University of Technology. Integration of optical fiber with sensitive thin films will new possibilities for industry application, such as optical fiber hydrogen sensors based on Pt-doped WO3 coatings, fiber humidity sensors with porous oxide coating and high-temperature sapphire fiber sensors based on multilayer coating on fiber tip. Ultra-weak FBG array with thousand of FBGs with on-line draw tower technology will enable FBG sensing network with large capacity, also improved sensing performance and mechanical stability.

  1. Optical fiber sensing of human skin emanations

    Science.gov (United States)

    Lee, S.-W.; Wang, T.; Selyanchyn, R.; Korposh, S.; James, S. W.

    2015-07-01

    An evanescent-wave optical fibre sensor modified with tetrakis(4-sulfophenyl)porphine (TSPP) and poly(allylamine hydrochloride) (PAH) bilayers using an layer-by-layer (LbL) approach was tested to measure the gas emitted from human skin. Optical intensity changes at different wavelengths in the transmission spectrum of the porphyrin-based film were induced by the human skin gas and measured as sensor response. Influence of relative humidity, which can be a major interference to sensor response, was significantly different when compared to the influence of skin emanations. Responses of the current optical sensor system could be considered as composite sensor array, where different optical wavelengths act as channels that have selective response to specific volatile compounds. Data obtained from the sensor system was analyzed through principal component analysis (PCA). This approach enabled to distinguish skin odors of different people and their altered physiological conditions after alcohol consumption.

  2. Dielectric annular core fiber for optical sensing.

    Czech Academy of Sciences Publication Activity Database

    Sola?ík, P.; Burian, Z.; Kašík, Ivan; Mat?jec, Vlastimil; Mrázek, Jan; Hayer, Miloš

    Bellingham : SPIE -International Society for Optic al Engineering, 2006 - (Culshaw, B.; Mignani, A.; Bartelt, H.; Jaroszewicz, L.), 61891R.1-61891R.9 ISBN 0-8194-6245-4. - (Proceedings of SPIE. 6189). [Photonics Europe. Strasbourg (FR), 03.04.2006-07.04.2006] R&D Projects: GA ?R(CZ) GA102/05/0948 Institutional research plan: CEZ:AV0Z2067918 Keywords : fibre optic sensorscapillarity Subject RIV: JB - Sensors, Measurment, Regulation

  3. Optical fiber current sensing based on Faraday effect in optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Sik; Kang, Hyun Seo; Lee, Jong Hun; Song Jung Tae; Lee Young Tak; Jung, Rae Sung [Sungkyunkwan University, Seoul (Korea, Republic of)

    1997-07-01

    Optical fiber current sensors based on the magnetooptic Faraday effect have been investigated as an alternative to conventional transformers. The Sagnac optical fiber current sensor by using a single mode fiber as a sensing medium is simpler than the polarimetric sensor with the input and output polarizer. Bur, the bending-induced linear birefringence existed in Sagnac loop reduces the long-term stability of Sagnac optical fiber current sensors. The stability of the Sagnac current sensors is also affected by vibration, stress, and temperature change. Two novel methods of stabilizing Sagnac current sensor developed in this work were presented. One method was realized by dividing the output of the ac current signal with the modulation signal output. As a result, the output of the sensor was stabilized within {+-}1.9%. The other method was characterized by creating an appropriate amount of circular birefringence into the Sagnac to remove the effect of the linear birefringence. We used a method of twisting a single mode fiber to induce a circular birefringence. The output of the sensor was stabilized within {+-}1.2% even under the application of pressing a portion of the fiber coil. When the twist-induced circular birefringence remains constant, the technique could be a good stabilization method. Bur, the twist-induced circular birefringence in single-mode fiber is sometimes temperature dependent. In this case, the output of the sensor drifts with temperature. To remove this drift problem, the twist-induced. circular birefringence needs to be readjusted as temperature changes. Here, we present another novel stabilization method which is realized by actively readjusting the twist-induced rotation angle to the maximum visibility point as the environmental condition changes. Employing the method, the stability of the sensor was demonstrated within {+-}1.7% even under the temperature change (36 deg C - 62 deg C). Also, the Sagnac current sensor shows good linearity up to 960 Arms. 30 refs., 19 figs. (author)

  4. Dielectric annular core fiber for optical sensing.

    Czech Academy of Sciences Publication Activity Database

    Sola?ík, P.; Burian, Z.; Kašík, Ivan; Mat?jec, Vlastimil; Mrázek, Jan; Hayer, Miloš

    Strasbourg : SPIE Europe, 2006. 215--. [Photonics Europe. 03.04.2006-07.04.2006, Strasbourg] R&D Projects: GA ?R(CZ) GA102/05/0948 Institutional research plan: CEZ:AV0Z20670512 Keywords : fibre optic sensors * capillarity * chemical analysis Subject RIV: JB - Sensors, Measurment, Regulation

  5. Frequency-Shifted Interferometry — A Versatile Fiber-Optic Sensing Technique

    OpenAIRE

    Fei Ye; Yiwei Zhang; Bing Qi; Li Qian

    2014-01-01

    Fiber-optic sensing is a field that is developing at a fast pace. Novel fiber-optic sensor designs and sensing principles constantly open doors for new opportunities. In this paper, we review a fiber-optic sensing technique developed in our research group called frequency-shifted interferometry (FSI). This technique uses a continuous-wave light source, an optical frequency shifter, and a slow detector. We discuss the operation principles of several FSI implementations and show their applicati...

  6. Calibration and Deployment of a Fiber-Optic Sensing System for Monitoring Debris Flows

    OpenAIRE

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

    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 inclu...

  7. Microwave assisted reconstruction of optical interferograms for distributed fiber optic sensing.

    Science.gov (United States)

    Huang, Jie; Hua, Lei; Lan, Xinwei; Wei, Tao; Xiao, Hai

    2013-07-29

    This paper reports a distributed fiber optic sensing technique through microwave assisted separation and reconstruction of optical interferograms in spectrum domain. The approach involves sending a microwave-modulated optical signal through cascaded fiber optic interferometers. The microwave signal was used to resolve the position and reflectivity of each sensor along the optical fiber. By sweeping the optical wavelength and detecting the modulation signal, the optical spectrum of each sensor can be reconstructed. Three cascaded fiber optic extrinsic Fabry-Perot interferometric sensors were used to prove the concept. Their microwave-reconstructed interferogram matched well with those recorded individually using an optical spectrum analyzer. The application in distributed strain measurement has also been demonstrated. PMID:23938685

  8. Reflection based Extraordinary Optical Transmission Fiber Optic Probe for Refractive Index Sensing

    OpenAIRE

    Lan, Xinwei; Cheng, Baokai; Yang, Qingbo; HUANG, JIE; Wang, Hanzheng; Ma, Yinfa; Shi, Honglan; Xiao, Hai

    2014-01-01

    Fiber optic probes for chemical sensing based on the extraordinary optical transmission (EOT) phenomenon are designed and fabricated by perforating subwavelength hole arrays on the gold film coated optical fiber endface. The device exhibits a red shift in response to the surrounding refractive index increases with high sensitivity, enabling a reflection-based refractive index sensor with a compact and simple configuration. By choosing the period of hole arrays, the sensor can be designed to o...

  9. Extreme temperature sensing using brillouin scattering in optical fibers

    CERN Document Server

    Fellay, Alexandre

    Stimulated Brillouin scattering in silica-based optical fibers may be considered from two different and complementary standpoints. For a physicist, this interaction of light and pressure wave in a material, or equivalently in quantum theory terms between photons and phonons, gives some glimpses of the atomic structure of the solid and of its vibration modes. For an applied engineer, the same phenomenon may be put to good use as a sensing mechanism for distributed measurements, thanks to the dependence of the scattered light on external parameters such as the temperature, the pressure or the strain applied to the fiber. As far as temperature measurements are concerned, Brillouin-based distributed sensors have progressively gained wide recognition as efficient systems, even if their rather high cost still restricts the number of their applications. Yet they are generally used in a relatively narrow temperature range around the usual ambient temperature; in this domain, the frequency of the scattered light incre...

  10. Development of self-sensing BFRP bars with distributed optic fiber sensors

    Science.gov (United States)

    Tang, Yongsheng; Wu, Zhishen; Yang, Caiqian; Shen, Sheng; Wu, Gang; Hong, Wan

    2009-03-01

    In this paper, a new type of self-sensing basalt fiber reinforced polymer (BFRP) bars is developed with using the Brillouin scattering-based distributed optic fiber sensing technique. During the fabrication, optic fiber without buffer and sheath as a core is firstly reinforced through braiding around mechanically dry continuous basalt fiber sheath in order to survive the pulling-shoving process of manufacturing the BFRP bars. The optic fiber with dry basalt fiber sheath as a core embedded further in the BFRP bars will be impregnated well with epoxy resin during the pulling-shoving process. The bond between the optic fiber and the basalt fiber sheath as well as between the basalt fiber sheath and the FRP bar can be controlled and ensured. Therefore, the measuring error due to the slippage between the optic fiber core and the coating can be improved. Moreover, epoxy resin of the segments, where the connection of optic fibers will be performed, is uncured by isolating heat from these parts of the bar during the manufacture. Consequently, the optic fiber in these segments of the bar can be easily taken out, and the connection between optic fibers can be smoothly carried out. Finally, a series of experiments are performed to study the sensing and mechanical properties of the propose BFRP bars. The experimental results show that the self-sensing BFRP bar is characterized by not only excellent accuracy, repeatability and linearity for strain measuring but also good mechanical property.

  11. 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.

  12. High temperature fiber optic microphone having a pressure-sensing reflective membrane under tensile stress

    Science.gov (United States)

    Zuckerwar, Allan J. (inventor); Cuomo, Frank W. (inventor); Robbins, William E. (inventor); Hopson, Purnell, Jr. (inventor)

    1992-01-01

    A fiber optic microphone is provided for measuring fluctuating pressures. An optical fiber probe having at least one transmitting fiber for transmitting light to a pressure-sensing membrane and at least one receiving fiber for receiving light reflected from a stretched membrane is provided. The pressure-sensing membrane may be stretched for high frequency response. Further, a reflecting surface of the pressure-sensing membrane may have dimensions which substantially correspond to dimensions of a cross section of the optical fiber probe. Further, the fiber optic microphone can be made of materials for use in high temperature environments, for example greater than 1000 F. A fiber optic probe is also provided with a backplate for damping membrane motion. The backplate further provides a means for on-line calibration of the microphone.

  13. Magnetic Sensing with Ferrofluid and Fiber Optic Connectors

    Directory of Open Access Journals (Sweden)

    Daniel Homa

    2014-02-01

    Full Text Available A simple, cost effective and sensitive fiber optic magnetic sensor fabricated with ferrofluid and commercially available fiber optic components is described in this paper. The system uses a ferrofluid infiltrated extrinsic Fabry-Perot interferometer (EFPI interrogated with an infrared wavelength spectrometer to measure magnetic flux density. The entire sensing system was developed with commercially available components so it can be easily and economically reproduced in large quantities. The device was tested with two different ferrofluid types over a range of magnetic flux densities to verify performance. The sensors readily detected magnetic flux densities in the range of 0.5 mT to 12.0 mT with measurement sensitivities in the range of 0.3 to 2.3 nm/mT depending on ferrofluid type. Assuming a conservative wavelength resolution of 0.1 nm for state of the art EFPI detection abilities, the estimated achievable measurement resolution is on the order 0.04 mT. The inherent small size and basic structure complimented with the fabrication ease make it well-suited for a wide array of research, industrial, educational and military applications.

  14. Multicore optical fiber grating array fabrication for medical sensing applications

    Science.gov (United States)

    Westbrook, Paul S.; Feder, K. S.; Kremp, T.; Taunay, T. F.; Monberg, E.; Puc, G.; Ortiz, R.

    2015-03-01

    In this work we report on a fiber grating fabrication platform suitable for parallel fabrication of Bragg grating arrays over arbitrary lengths of multicore optical fiber. Our system exploits UV transparent coatings and has precision fiber translation that allows for quasi-continuous grating fabrication. Our system is capable of both uniform and chirped fiber grating array spectra that can meet the demands of medical sensors including high speed, accuracy, robustness and small form factor.

  15. Frequency-Shifted Interferometry — A Versatile Fiber-Optic Sensing Technique

    Directory of Open Access Journals (Sweden)

    Fei Ye

    2014-06-01

    Full Text Available Fiber-optic sensing is a field that is developing at a fast pace. Novel fiber-optic sensor designs and sensing principles constantly open doors for new opportunities. In this paper, we review a fiber-optic sensing technique developed in our research group called frequency-shifted interferometry (FSI. This technique uses a continuous-wave light source, an optical frequency shifter, and a slow detector. We discuss the operation principles of several FSI implementations and show their applications in fiber length and dispersion measurement, locating weak reflections along a fiber link, fiber-optic sensor multiplexing, and high-sensitivity cavity ring-down measurement. Detailed analysis of FSI system parameters is also presented.

  16. Optical sensing in high voltage transmission lines using power over fiber and free space optics

    Science.gov (United States)

    Rosolem, João Batista; Bassan, Fabio Renato; Penze, Rivael Strobel; Leonardi, Ariovaldo Antonio; Fracarolli, João Paulo Vicentini; Floridia, Claudio

    2015-12-01

    In this work we propose the use of power over fiber (PoF) and free space optics (FSO) techniques to powering and receive signals from an electrical current sensor placed at high voltage potential using a pair of optical collimators. The technique evaluation was performed in a laboratorial prototype using 62.5/125 ?m multimode fiber to study the sensitivity of the optical alignment and the influence of the collimation process in the sensing system wavelengths: data communication (1310 nm) and powering (830 nm). The collimators were installed in a rigid electric insulator in order to maintain the stability of transmission.

  17. Biochemical sensing application based on optical fiber evanescent wave sensor

    Science.gov (United States)

    Lv, Xiaoyi; Mo, Jiaqing; Xu, Liang; Jia, Zhenhong

    2015-08-01

    We have designed a novel evanescent field fiber optic biosensors with porous silicon dioxide cladding. The pore size of porous silicon dioxide cladding is about 100 nm in diameter. Biological molecules were immobilized to the porous silicon dioxide cladding used APTES and glutaraldehyde. Refractive index of cladding used Bruggemann's effective medium theory. We carried out simulations of changing in light intensity in optical fiber before and after chemical coupling of biomolecules. This novel optical fiber evanescent wave biosensor has a great potential in clinical chemistry for rapid and convenient determination of biological molecule.

  18. Surface plasmon sensing of gas phase contaminants using optical fiber

    International Nuclear Information System (INIS)

    Fiber-optic gas phase surface plasmon resonance (SPR) detection of several contaminant gases of interest to state-of-health monitoring in high-consequence sealed systems has been demonstrated. These contaminant gases include H2, H2S, and moisture using a single-ended optical fiber mode. Data demonstrate that results can be obtained and sensitivity is adequate in a dosimetric mode that allows periodic monitoring of system atmospheres. Modeling studies were performed to direct the design of the sensor probe for optimized dimensions and to allow simultaneous monitoring of several constituents with a single sensor fiber. Testing of the system demonstrates the ability to detect 70mTorr partial pressures of H2 using this technique and 2S. In addition, a multiple sensor fiber has been demonstrated that allows a single fiber to measure H2, H2S, and H2O without changing the fiber or the analytical system.

  19. Asymmetrically and symmetrically coated tapered optical fiber for sensing applications

    Science.gov (United States)

    Del Villar, Ignacio; Socorro, Abian B.; Corres, Jesus M.; Arregui, Francisco J.; Matias, Ignacio R.

    2015-09-01

    The deposition of a non-metallic thin-film in a symmetrically coated tapered optical fiber leads to the generation of resonances due to guidance of a mode in the thin-film. At certain conditions, the resonances overlap each other, which can be avoided with an asymmetric coated tapered optical fiber, which permits to obtain resonances for TM and TE polarization separately. Numerical results showing the sensitivity to coating thickness and surrounding medium refractive index are also presented for both polarizations.

  20. Spectral peak tracking for enhanced fiber optic sensing

    Science.gov (United States)

    Plattner, Markus P.; Brand, C. N.; Mair, T.; Schupfer, S.; Buck, T. C.; Koch, A. W.

    2009-06-01

    Within this work, we describe our newly developed interrogation scheme for fiber optic sensing applications. This measurement system will be utilized in Ariane launchers for monitoring temperature and mechanical stress distribution during flight. The acquired sensing data can be used to control propulsion unit an thrusters and thereby adapt the flight path in a way that damage on the launcher is prevented. In order to detect the peak wavelength of e.g. fiber Bragg grating (FBG) sensors, a tunable laser source based on a modulated-grating laser diode is able to scan through a more than 40nm wide spectrum in the infrared region. Several sensors with different spectral answers can be placed inside one sensor fiber and then interrogated sequentially. The magnitudes of the reflected intensities depend on the actual sensor position that is determined by the measurand (e.g. temperature). One single sensor is scanned by a variable number of spectral sampling points and the spectral answer of the sensor is then calculated by centroid algorithms. Depending an the spectral width of one sensor, the number of sensors that shall be interrogated and the required sampling points per sensor, a maximum sampling frequency of 240kHz is achievable with our hardware. Contrary to comparable systems, our interrogator is capable of switching to any available wavelength of its spectrum within a couple of nanoseconds. Therefore standard continuous sweeping through the entire spectrum is not necessary. This results in a new measurement scheme, wherein spectral gaps between consecutive sensors do not need to be scanned and can be skipped. Since most of the spectrum consists of the gaps between the sensors, overall measurement time is thereby reduced significantly. One problem arises from this measurement scheme: Due to the fact that the sensor's spectral answers vary in time, a special algorithm for tracking the spectral movement has to be implemented. The scope of this work is the description, implementation and assessment of this new peak tracking procedure. After describing the measurement setup, we will therefore explain the algorithm behind the peak tracking measurement. Afterwards the simulation process is explained and results are shown. Performance obtained by peak tracking compared to standard continuous wavelength scanning is evaluated in detail and further development steps which are necessary to obtain a fully sophisticated interrogation systems are discussed.

  1. Probing the Ultimate Limit of Fiber-Optic Strain Sensing

    Science.gov (United States)

    Gagliardi, G.; Salza, M.; Avino, S.; Ferraro, P.; De Natale, P.

    2010-11-01

    The measurement of relative displacements and deformations is important in many fields such as structural engineering, aerospace, geophysics, and nanotechnology. Optical-fiber sensors have become key tools for strain measurements, with sensitivity limits ranging between 10â??9 and 10â??6ε hertz (Hz)â??1/2 (where ε is the fractional length change). We report on strain measurements at the 10â??13ε-Hzâ??1/2 level using a fiber Bragg-grating resonator with a diode-laser source that is stabilized against a quartz-disciplined optical frequency comb, thus approaching detection limits set by thermodynamic phase fluctuations in the fiber. This scheme may provide a route to a new generation of strain sensors that is entirely based on fiber-optic systems, which are aimed at measuring fundamental physical quantities; for example, in gyroscopes, accelerometers, and gravity experiments.

  2. Fiber-optic multipoint radiation sensing system using waveguide scintillators

    International Nuclear Information System (INIS)

    Novel fiber-optic radiation sensors and a multipoint measurement method that takes advantage of them have been developed. The new sensor design, which we call a 'waveguide scintillator', consists of a scintillating material and a wavelength-shifting fiber (WLSF). The WLSF is embedded in the scintillating material, and each end is connected to a transparent optical fiber. These waveguide scintillators can be connected in series along an optical fiber loop to form a radiation monitoring system, and each end of the fiber loop is terminated with a photodetector. This new radiation monitoring arrangement dispenses with the need for electronic apparatus at each measuring point and consequently improves resistance to noise. Furthermore, it offers the advantages of multipoint monitoring - meaning that radiation intensity can be measured at multiple sensors - using only two photodetectors. We have examined the light output characteristics and time resolution of a prototype arrangement of these new waveguide scintillators, thus confirming the feasibility of multipoint measurements using a system of multiple waveguide scintillators connected in series in an optical fiber loop. (author)

  3. Remote Management for Multipoint Sensing Systems Using Hetero-Core Spliced Optical Fiber Sensors

    Science.gov (United States)

    Goh, Lee See; Anoda, Yuji; Kazuhiro, Watanabe; Shinomiya, Norihiko

    2014-01-01

    This paper describes the design and experimental verification of a multipoint sensing system with hetero-core spliced optical fiber sensors and its remote management using an internet-standard protocol. The study proposes two different types of design and conducts experiments to verify those systems' feasibility. In order to manage the sensing systems remotely, the management method uses a standard operation and maintenance protocol for internet: the Simple Network Management Protocol is proposed. The purpose of this study is to construct a multipoint sensing system remote management tool by which the system can also determine the status and the identity of fiber optic sensors. The constructed sensing systems are verified and the results have demonstrated that the first proposed system can distinguish the responses from different hetero-core spliced optical fiber sensors remotely. The second proposed system shows that data communications are performed successfully while identifying the status of hetero-core spliced optical fiber sensors remotely. PMID:24379051

  4. Chalcogenide optical fibers for mid-infrared sensing

    Science.gov (United States)

    Bureau, Bruno; Boussard, Catherine; Cui, Shuo; Chahal, Radwan; Anne, Marie Laure; Nazabal, Virginie; Sire, Olivier; Loréal, Olivier; Lucas, Pierre; Monbet, Valérie; Doualan, Jean-Louis; Camy, Patrice; Tariel, Hugues; Charpentier, Frédéric; Quetel, Lionel; Adam, Jean-Luc; Lucas, Jacques

    2014-02-01

    Chalcogenide glasses are a matchless material as far as mid-infrared (IR) applications are concerned. They transmit light typically from 2 to 12 ?m and even as far as 20 ?m depending on their composition, and numerous glass compositions can be designed for optical fibers. One of the most promising applications of these fibers consists in implementing fiber evanescent wave spectroscopy, which enables detection of the mid-IR signature of most biomolecules. The principles of fiber evanescent wave spectroscopy are recalled together with the benefit of using selenide glass to carry out this spectroscopy. Then, two large-scale studies in recent years in medicine and food safety are exposed. To conclude, the future strategy is presented. It focuses on the development of rare earth-doped fibers used as mid-IR sources on one hand and tellurium-based glasses to shift the limit of detection toward longer wavelength on the other hand.

  5. Liquid Seal for Temperature Sensing with Fiber-Optic Refractometers

    OpenAIRE

    Ben Xu; Jianqing Li; Yi Li; Jianglei Xie; Xinyong Dong

    2014-01-01

    Liquid sealing is an effective method to convert a fiber-optic refractometer into a simple and highly sensitive temperature sensor. A refractometer based on the thin-core fiber modal interferometer is sealed in a capillary tube filled with Cargille oil. Due to the thermo-optic effect of the sealing liquid, the high refractive-index sensitivity refractometer is subsequently sensitive to the ambient temperature. It is found that the liquid-sealed sensor produces a highest sensitivity of ?2.30 n...

  6. Research on spectral resource optimization and self-healing technology of hybrid optical fiber sensing network

    Science.gov (United States)

    Chen, Cheng; Sang, Mei; Ge, Chunfeng; Chen, Guanghui; Liu, Tiegen

    2015-08-01

    We propose an optical-fiber-sensing-network (OFSN) to allow hybrid fiber sensors working in the same network and it achieves self-healing function. The discrete and distributed optical fiber sensors can be connected in sub-layers of the network. WDM-OTDM technique is introduced to convert multi-wavelengths of light source into a specific arranged wavelength in each sub-layer. Thus every sub-layer can share the system spectrum resources, and sensing signals of each sub-layer are transmitted together in the backbone network. To achieve self-healing function, double-ring structure is adopted in the backbone network. Node microprocessor program is designed to make switching to the protect fiber when working fiber is broken. The experimental backbone setup of the network demonstrates the practical reliability and intelligence of the optical sensing network.

  7. Reflection based Extraordinary Optical Transmission Fiber Optic Probe for Refractive Index Sensing.

    Science.gov (United States)

    Lan, Xinwei; Cheng, Baokai; Yang, Qingbo; Huang, Jie; Wang, Hanzheng; Ma, Yinfa; Shi, Honglan; Xiao, Hai

    2014-03-31

    Fiber optic probes for chemical sensing based on the extraordinary optical transmission (EOT) phenomenon are designed and fabricated by perforating subwavelength hole arrays on the gold film coated optical fiber endface. The device exhibits a red shift in response to the surrounding refractive index increases with high sensitivity, enabling a reflection-based refractive index sensor with a compact and simple configuration. By choosing the period of hole arrays, the sensor can be designed to operate in the near infrared telecommunication wavelength range, where the abundant source and detectors are available for easy instrumentation. The new sensor probe is demonstrated for refractive index measurement using refractive index matching fluids. The sensitivity reaches 573 nm/RIU in the 1.333~1.430 refractive index range. PMID:24574579

  8. Single-frequency linear cavity erbium-doped fiber laser for fiber-optic sensing applications

    International Nuclear Information System (INIS)

    We report a short-cavity fiber laser configured with a high-concentration erbium-doped fiber with stable single-frequency output. The fiber laser utilized a fiber Bragg grating inscribed into a piece of polarization-maintaining optical fiber as the output coupler to ensure a stable single frequency laser output. The polarization-maintaining optical fiber used in the output coupler is intended to provide the linearly polarized single-frequency laser output. The fiber laser had a maximum hundreds of micron-Watt level power output pumped by a fiber pigtailed laser diode working at 980 nm. Mode hopping phenomenon was eliminated in such a short-cavity fiber laser. Laser frequency stability less than 400 MHz over 10 minutes was obtained

  9. An Implantable Neural Sensing Microsystem with Fiber-Optic Data Transmission and Power Delivery

    OpenAIRE

    Yoon-Kyu Song; Nurmikko, Arto V.; Mingyu Kang; Sunmee Park; David A. Borton

    2013-01-01

    We have developed a prototype cortical neural sensing microsystem for brain implantable neuroengineering applications. Its key feature is that both the transmission of broadband, multichannel neural data and power required for the embedded microelectronics are provided by optical fiber access. The fiber-optic system is aimed at enabling neural recording from rodents and primates by converting cortical signals to a digital stream of infrared light pulses. In the full microsystem whose performa...

  10. A reflection-based localized surface plasmon resonance fiber-optic probe for biochemical sensing

    OpenAIRE

    Lin, Yongbin; Zou, Yang; Lindquist, Robert G.

    2011-01-01

    We report the fabrication and characterization of an optical fiber biochemical sensing probe based on localized surface plasmon resonance (LSPR) and spectra reflection. Ordered array of gold nanodots was fabricated on the optical fiber end facet using electron-beam lithography (EBL). We experimentally demonstrated for the first time the blue shift of the LSPR scattering spectrum with respected to the LSPR extinction spectrum, which had been predicted theoretically. High sensitivity [195.72 nm...

  11. 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.

  12. Electrically Insulated Sensing of Respiratory Rate and Heartbeat Using Optical Fibers

    Directory of Open Access Journals (Sweden)

    Ernesto Suaste-Gómez

    2014-11-01

    Full Text Available Respiratory and heart rates are among the most important physiological parameters used to monitor patients’ health. It is important to design devices that can measure these parameters without risking or altering the subject’s health. In this context, a novel sensing method to monitor simultaneously the heartbeat and respiratory rate signals of patients within an electrically safety environment was developed and tested. An optical fiber-based sensor was used in order to detect two optical phenomena. Photo-plethysmography and the relation between bending radius and attenuation of optical fiber were coupled through a single beam light traveling along this fiber.

  13. Refractive index sensing using V-shaped polymer optical fibers

    Science.gov (United States)

    Lee, Heeyoung; Hayashi, Neisei; Mizuno, Yosuke; Nakamura, Kentaro

    2015-11-01

    Although polymer optical fiber (POF) tapers with high flexibility have been used to measure the refractive indices (RIs) of liquids, their fabrication have caused some inconvenience including the need to use external heat sources or chemicals. Here, as an alternative, we develop a simple, secure, and low-cost method of measuring RIs of liquids using V-shaped bent POFs. When the bending angle is 120° (experimentally optimized), with increasing RI, the transmitted power increases almost linearly with a dependence coefficient of approximately 210 dB/RI unit.

  14. An optical fiber sensing technique for temperature distribution measurements in microwave heating

    Science.gov (United States)

    Wada, Daichi; Sugiyama, Jun-ichi; Zushi, Hiroaki; Murayama, Hideaki

    2015-08-01

    We introduce an optical fiber sensing technique that can measure the temperature distributions along a fiber during microwave heating. We used a long-length fiber Bragg grating (FBG) as an electromagnetic-immune sensor and interrogated temperature distributions along the FBG by an optical frequency domain reflectometry. Water in a glass tube with a length of 820?mm was heated in a microwave oven, and its temperature distribution along the glass tube was measured using the sensing system. The temperature distribution was obtained in 5?mm intervals. Infrared radiometry was also used to compare the temperature measurement results. Time and spatial variations of the temperature distribution profiles were monitored for several microwave input powers. The results clearly depict inhomogeneous temperature profiles. The applicability and effectiveness of the optical fiber distributed measurement technique in microwave heating are demonstrated.

  15. Fiber optic medical pressure-sensing system employing intelligent self-calibration

    Science.gov (United States)

    He, Gang

    1996-01-01

    In this article, we describe a fiber-optic catheter-type pressure-sensing system that has been successfully introduced for medical diagnostic applications. We present overall sensors and optoelectronics designs, and highlight product development efforts that lead to a reliable and accurate disposable pressure-sensing system. In particular, the incorporation of an intelligent on-site self-calibration approach allows limited sensor reuses for reducing end-user costs and for system adaptation to wide sensor variabilities associated with low-cost manufacturing processes. We demonstrate that fiber-optic sensors can be cost-effectively produced to satisfy needs of certain medical market segments.

  16. Chalcogenide glass fibers: Optical window tailoring and suitability for bio-chemical sensing

    Science.gov (United States)

    Lucas, Pierre; Coleman, Garrett J.; Jiang, Shibin; Luo, Tao; Yang, Zhiyong

    2015-09-01

    Glassy materials based on chalcogen elements are becoming increasingly prominent in the development of advanced infrared sensors. In particular, infrared fibers constitute a desirable sensing platform due to their high sensitivity and versatile remote collection capabilities for in-situ detection. Tailoring the transparency window of an optical material to the vibrational signature of a target molecule is important for the design of infrared sensor, and particularly for fiber evanescent wave spectroscopy. Here we review the basic principles and recent developments in the fabrication of chalcogenide glass infrared fibers for application as bio-chemical sensors. We emphasize the challenges in designing materials that combine good rheological properties with chemical stability and sufficiently wide optical windows for bio-chemical sensing. The limitation in optical transparency due to higher order overtones of the amorphous network vibrations is established for this family of glasses. It is shown that glasses with wide optical window suffer from higher order overtone absorptions. Compositional engineering with heavy elements such as iodine is shown to widen the optical window but at the cost of lower chemical stability. The optical attenuations of various families of chalcogenide glass fibers are presented and weighed for their applications as chemical sensors. It is then shown that long-wave infrared fibers can be designed to optimize the collection of selective signal from bio-molecules such as cells and tissues. Issues of toxicity and mechanical resistance in the context of bio-sensing are also discussed.

  17. Assessment of fiber optic sensors and other advanced sensing technologies for nuclear power plants

    International Nuclear Information System (INIS)

    As a result of problems such as calibration drift in nuclear plant pressure sensors and the recent oil loss syndrome in some models of Rosemount pressure transmitters, the nuclear industry has become interested in fiber optic pressure sensors. Fiber optic sensing technologies have been considered for the development of advanced instrumentation and control (I ampersand C) systems for the next generation of reactors and in older plants which are retrofitted with new I ampersand C systems. This paper presents the results of a six-month Phase I study to establish the state-of-the-art in fiber optic pressure sensing. This study involved a literature review, contact with experts in the field, an industrial survey, a site visit to a fiber optic sensor manufacturer, and laboratory testing of a fiber optic pressure sensor. The laboratory work involved both static and dynamic performance tests. This initial Phase I study has recently been granted a two-year extension by the U.S. Nuclear Regulatory Commission (NRC). The next phase will evaluate fiber optic pressure sensors in specific nuclear plant applications in addition to other advanced methods for monitoring critical nuclear plant equipment

  18. Assessment of fiber optic sensors and other advanced sensing technologies for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hashemian, H.M. [Analysis and Measurement Services Corporation, Knoxville, TN (United States)

    1996-03-01

    As a result of problems such as calibration drift in nuclear plant pressure sensors and the recent oil loss syndrome in some models of Rosemount pressure transmitters, the nuclear industry has become interested in fiber optic pressure sensors. Fiber optic sensing technologies have been considered for the development of advanced instrumentation and control (I&C) systems for the next generation of reactors and in older plants which are retrofitted with new I&C systems. This paper presents the results of a six-month Phase I study to establish the state-of-the-art in fiber optic pressure sensing. This study involved a literature review, contact with experts in the field, an industrial survey, a site visit to a fiber optic sensor manufacturer, and laboratory testing of a fiber optic pressure sensor. The laboratory work involved both static and dynamic performance tests. This initial Phase I study has recently been granted a two-year extension by the U.S. Nuclear Regulatory Commission (NRC). The next phase will evaluate fiber optic pressure sensors in specific nuclear plant applications in addition to other advanced methods for monitoring critical nuclear plant equipment.

  19. Characterization of Flexible Copolymer Optical Fibers for Force Sensing Applications

    Directory of Open Access Journals (Sweden)

    Lukas J. Scherer

    2013-09-01

    Full Text Available In this paper, different polymer optical fibres for applications in force sensing systems in textile fabrics are reported. The proposed method is based on the deflection of the light in fibre waveguides. Applying a force on the fibre changes the geometry and affects the wave guiding properties and hence induces light loss in the optical fibre. Fibres out of three different elastic and transparent copolymer materials were successfully produced and tested. Moreover, the influence of the diameter on the sensing properties was studied. The detectable force ranges from 0.05 N to 40 N (applied on 3 cm of fibre length, which can be regulated with the material and the diameter of the fibre. The detected signal loss varied from 0.6% to 78.3%. The fibres have attenuation parameters between 0.16–0.25 dB/cm at 652 nm. We show that the cross-sensitivies to temperature, strain and bends are low. Moreover, the high yield strength (0.0039–0.0054 GPa and flexibility make these fibres very attractive candidates for integration into textiles to form wearable sensors, medical textiles or even computing systems.

  20. Optically heated fiber Bragg grating in active fibers for low temperature sensing application

    Science.gov (United States)

    Qi, Lin; Jin, Long; Guan, Bai-Ou

    2013-09-01

    Optically heated fiber Bragg gratings due to the absorption over the fiber core in rare-earth doped fibers are experimentally demonstrated. Bragg wavelength variations with pump power are measured for different fibers. We found that the Er/Yb-codoped fiber presents the strongest thermal effect, due to the high absorption. A maximum wavelength shift of 1.34 nm can be obtained when the 980 nm pump power is 358 mW under room temperature, suggesting the fiber is heated up to over 100 °C. Furthermore, the thermal effect is enhanced by pumping the surrounding air to close to vacuum. A wavelength shift of 1.69 nm is attained, due to the weakened ability of heat transfer at the silica-air interface. The optical heating presents a very short response time and can found applications in low temperature circumstances.

  1. Erbium doped optical fiber lasers for magnetic field sensing

    Science.gov (United States)

    Nascimento, I. M.; Baptista, J. M.; Jorge, P. A. S.; Cruz, J. L.; Andrés, M. V.

    2015-09-01

    In this work two erbium doped optical fiber laser configurations for magnetic field measurement are implemented and compared. The first laser is set-up in a loop configuration and requires only a single FBG (Fiber Bragg Grating), acting as mirror. A second laser employs a simpler linear cavity configuration but requires two FBGs with spectral overlap to form the laser cavity. A bulk magnetostrictive material made of Terfenol-D is attached to the laser FBGs enabling modulation of its operation wavelength by the magnetic field. Moreover, a passive interferometer was developed to demodulate the AC magnetic field information where the corresponding demodulation algorithms were software based. Both configurations are tested and compared with the results showing different sensitivities and resolutions. Better performance was accomplished with the double FBGs linear cavity configuration with a resolution of 0.05 mTRMS in the range of 8 to 16 mTRMS. For the same range the loop configuration attained a resolution of 0.48 mTRMS.

  2. 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.

  3. Application of a distributed optical fiber sensing technique in monitoring the stress of precast piles

    International Nuclear Information System (INIS)

    Due to its ability in providing long distance, distributed sensing, the optical fiber sensing technique based on a Brillouin optical time domain reflectometer (BOTDR) has a unique advantage in monitoring the stability and safety of linear structures. This paper describes the application of a BOTDR-based technique to measure the stress within precast piles. The principle behind the BOTDR and the embedding technique for the sensing optical fiber in precast piles is first introduced, and then the analysis method and deformation and stress calculation based on distributed strain data are given. Finally, a methodology for using a BOTDR-based monitoring workflow for in situ monitoring of precast piles, combined with a practical example, is introduced. The methodology requires implantation of optical fibers prior to pile placement. Field experimental results show that the optical fiber implantation method with slotting, embedding, pasting and jointing is feasible, and have accurately measured the axial force, side friction, end-bearing resistance and bearing feature of the precast pile according to the strain measuring data. (paper)

  4. Fiber Optic Sensing Monitors Strain and Reduces Costs

    Science.gov (United States)

    2008-01-01

    In applications where stress on a structure may vary widely and have an unknown impact on integrity, a common engineering strategy has been overbuilding to ensure a sufficiently robust design. While this may be appropriate in applications where weight concerns are not paramount, space applications demand a bare minimum of mass, given astronomical per-pound launch costs. For decades, the preferred solution was the tactic of disassembly and investigation between flights. Knowing there must be a better way, Dr. Mark Froggatt, of Langley Research Center, explored alternate means of monitoring stresses and damage to the space shuttle. While a tear-it-apart-and-have-a-look strategy was effective, it was also a costly and time consuming process that risked further stresses through the very act of disassembly and reassembly. An alternate way of monitoring the condition of parts under the enormous stresses of space flight was needed. Froggatt and his colleagues at Langley built an early-warning device to provide detailed information about even minuscule cracks and deformations by etching a group of tiny lines, or grating, on a fiber optic cable five-thousandths of an inch thick with ultraviolet light. By then gluing the fiber to the side of a part, such as a fuel tank, and shining a laser beam down its length, reflected light indicated which gratings were under stress. Inferring this data from measurements in light rather than in bonded gauges saved additional weight. Various shuttle components now employ the ultrasonic dynamic vector stress sensor (UDVSS), allowing stress detection by measuring light beamed from a built-in mini-laser. By measuring changes in dynamic directional stress occurring in a material or structure, and including phase-locked loop, synchronous amplifier, and contact probe, the UDVSS proved especially useful among manufacturers of aerospace and automotive structures for stress testing and design evaluation. Engineers could ensure safety in airplanes and spaceships with a narrower, not overbuilt, margin of safety. For this development, in 1997, Discover Magazine named Froggatt a winner in the "Eighth Annual Awards for Technological Innovation" from more than 4,000 entries.

  5. Design and Fabrication of Fiber-Optic Nanoprobes for Optical Sensing

    OpenAIRE

    Zhang Yan; Dhawan Anuj; Vo-Dinh Tuan

    2010-01-01

    Abstract This paper describes the design and fabrication of fiber-optic nanoprobes developed for optical detection in single living cells. It is critical to fabricate probes with well-controlled nanoapertures for optimized spatial resolution and optical transmission. The detection sensitivity of fiber-optic nanoprobe depends mainly on the extremely small excitation volume that is determined by the aperture sizes and penetration depths. We investigate the angle dependence of the aperture in sh...

  6. Development of optical fibers for mid-infrared sensing: state of the art and recent achievements

    Science.gov (United States)

    Bureau, Bruno; Boussard-Plédel, Catherine; Troles, Johann; Nazabal, Virginie; Adam, Jean-Luc; Doualan, Jean-Louis; Braud, Alain; Camy, Patrice; Lucas, Pierre; Brilland, Laurent; Quetel, Lionel; Tariel, Hugues

    2015-05-01

    Chalcogenide glass fibers are matchless devices to collect mi-infrared signal. Depending on the spectroscopic strategy, different kind of optical fibers have been developed during the past 10 years. The first fibers have been fabricated from selenide glasses to implement Fiber Evanescent Wave Spectroscopy (FEWS). It is an efficient way to collect optical spectra in situ, in real time and even, in the future, in vivo. Thanks to selenide glass fibers, it is possible to record such spectra on the mid-infrared range from 2 to 11 ?m. This working window gives access to the fundamental vibration band of most of biological molecules and numerous multi-disciplinary works have been led in biology and medicine. New glasses, only based on tellurium, have been recently developed, initially in the frame of the Darwin mission led by the European Space Agency (ESA). These glasses transmit light further toward the farinfrared and permit to reach the absorption band of CO2 located at 15 ?m as requested by the ESA. Moreover, these telluride glass fiber are also very interesting for FEWS and medical application. Indeed, they give access to the mid-infrared signal of biomolecules beyond 11 ?m, where classical selenide glass fibers are blind. Alternatively, in order to fight against global warning, some optical fibers have been developed for the monitoring of the CO2 stored into geological storage area underground. These fibers were doped with Dy3+ which emits a broad fluorescent band embedding the CO2 absorption band at 4.3 ?m. thus, these fibers are used both to transmit light and as secondary sources in the mid-infrared. To conclude, original microstructurated fibers have also been used for mid-infrared sensing. They exhibit a nice sensitivity compared to classical chalcogenide glass fibers.

  7. Coherence sensing of time-addressed optical-fiber sensors illuminated by a multimode laser diode.

    Science.gov (United States)

    Santos, J L; Jackson, D A

    1991-12-01

    A reflective array of optical-fiber sensors multiplexed in time and with their status read using coherence sensing associated with directly modulated multimode laser-diode illumination is investigated. Sensor sensitivity as determined by primary noise sources is evaluated and numerical results are presented. The concept is demonstrated with two all-fiber Michelson interferometers and applied to the measurement of periodic and quasi-static parameters. It is shown that the effect of feedback light into the laser cavity on the level of the system noise floor is negligible, making unnecessary the use of source optical isolation. PMID:20717322

  8. Sensing characteristics of clad-modified with nanocrystalline metal oxide fiber optic gas sensor

    Science.gov (United States)

    Sastikumar, D.; Renganathan, B.

    2014-11-01

    Clad-modified with nanocrystalline metal oxide fiber optic gas sensors have been proposed for ambient temperature operation. The sensor output light intensity either increases or decreases when the gas concentration is increased. Study shows that optical properties of metal-oxides with air medium influence the gas sensing. Absorption characteristics of nanocrystalline metal oxides ( ZnO, Sm2O3 and Ce doped ZnO etc., ) in air, methanol, ethanol and ammonia are analyzed as well as their effect on gas sensing.

  9. Ce-doped SiO2 optical fibers for remote radiation sensing and measurement

    Science.gov (United States)

    Chiodini, Norberto; Vedda, Anna; Fasoli, Mauro; Moretti, Federico; Lauria, Alessandro; Cantone, Marie Claire; Veronese, Ivan; Tosi, Giampiero; Brambilla, Marco; Cannillo, Barbara; Mones, Eleonora; Brambilla, Gilberto; Petrovich, Marco

    2009-05-01

    Scintillating materials, able to convert energy of ionizing radiation into light in the visible-UV interval, are presently used in a wide class of applications such as medical imaging, industrial inspection, security controls and high energy physics detectors. In the last few years we studied and developed a new radiation sensor based on silica-glass fiber-optic technology. In its simplest configuration such device is composed by a short portion (about 10 mm) of scintillating fiber coupled to a photomultiplier through a suitably long passive silica fiber. In this work, we present new results concerning the characterization of silica based Ce and Eu doped fibers glasses obtained by a modified sol-gel method and drawn by a conventional drawing tower for optical fibers. The radio-luminescence of Eu doped fibers is rather weak; moreover it displays a marked sensitivity increase during subsequent irradiations, preventing the use of such fibers in dosimetry. On the other hand Ce-doped fibers show very high radiation hardness, signal stability and reproducibility, and high sensitivity to radiations with energies from 10 keV to several tens of MeV. Numerous tests with photons (X and gamma rays), electrons, and protons have already been successfully performed. At the early stage of its market introduction it is the smallest radiation sensor, also compared to MOSFET and diode technology and it appears to be the ideal choice for in vivo measurements in medical field or remote sensing.

  10. Fiber Loop Ringdown — a Time-Domain Sensing Technique for Multi-Function Fiber Optic Sensor Platforms: Current Status and Design Perspectives

    OpenAIRE

    Chuji Wang

    2009-01-01

    Fiber loop ringdown (FLRD) utilizes an inexpensive telecommunications light source, a photodiode, and a section of single-mode fiber to form a uniform fiber optic sensor platform for sensing various quantities, such as pressure, temperature, strain, refractive index, chemical species, biological cells, and small volume of fluids. In FLRD, optical losses of a light pulse in a fiber loop induced by changes in a quantity are measured by the light decay time constants. FLRD measures time to detec...

  11. 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)

  12. Fiber Optic Shape Sensing for Tethered Marsupial Rovers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna Innovations Incorporated is proposing to design, build, and test a shape, length, and tension sensing tether for robotic exploration and sample-gathering...

  13. Fiber Optic Shape Sensing for Tethered Marsupial Rovers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Building upon the successful proof of concept work in Phase I, Luna Innovations Incorporated is proposing to design, build, and test a sensing tether for marsupial...

  14. OptaSense distributed acoustic and seismic sensing using COTS fiber optic cables for infrastructure protection and counter terrorism

    Science.gov (United States)

    Duckworth, Gregory L.; Ku, Emery M.

    2013-06-01

    The OptaSense® Distributed Acoustic Sensing (DAS) technology can turn any cable with single-mode optical fiber into a very large and densely sampled acoustic/seismic sensor array—covering up to a 50 km aperture per system with "virtual" sensor separations as small as 1 meter on the unmodified cable. The system uses Rayleigh scattering from the imperfections in the fiber to return the optical signals measuring local fiber strain from seismic or air and water acoustic signals. The scalable system architecture can provide border monitoring and high-security perimeter and linear asset protection for a variety of industries—from nuclear facilities to oil and gas pipelines. This paper presents various application architectures and system performance examples for detection, localization, and classification of personnel footsteps, vehicles, digging and tunneling, gunshots, aircraft, and earthquakes. The DAS technology can provide a costeffective alternative to unattended ground sensors and geophone arrays, and a complement or alternative to imaging and radar sensors in many applications. The transduction, signal processing, and operator control and display technology will be described, and performance examples will be given from research and development testing and from operational systems on pipelines, critical infrastructure perimeters, railroads, and roadways. Potential new applications will be discussed that can take advantage of existing fiber-optic telecommunications infrastructure as "the sensor"—leading to low-cost and high-coverage systems.

  15. A reflection-based localized surface plasmon resonance fiber-optic probe for biochemical sensing.

    Science.gov (United States)

    Lin, Yongbin; Zou, Yang; Lindquist, Robert G

    2011-01-01

    We report the fabrication and characterization of an optical fiber biochemical sensing probe based on localized surface plasmon resonance (LSPR) and spectra reflection. Ordered array of gold nanodots was fabricated on the optical fiber end facet using electron-beam lithography (EBL). We experimentally demonstrated for the first time the blue shift of the LSPR scattering spectrum with respected to the LSPR extinction spectrum, which had been predicted theoretically. High sensitivity [195.72 nm/refractive index unit (RIU)] of this sensor for detecting changes in the bulk refractive indices has been demonstrated. The label-free affinity bio-molecules sensing capability has also been demonstrated using biotin and streptavidin as the receptor and the analyte. PMID:21412453

  16. Sensing nanometric displacement of a micro-/nano-fiber induced by optical forces by use of white light interferometry

    Science.gov (United States)

    Qiu, Weiqia; Huang, Hankai; Yu, Jianhui; Dong, Huazhuo; Chen, Zhe; Lu, Huihui

    2015-07-01

    Sensing the nanometric displacement of a micro-/nano-fiber induced by optical forces is a key technology to study optical forces and optical momentum. When the gap between a micro-/nano-fiber and glass substrate becomes down to micrometer scale or less, a white light interference was observed. The gap changes when optical force arising from the propagating pump light along the micro-/nano-fiber causes a transversal nanometric displacement of a micro-/nanofiber, resulting in movement of the interferometric fringes. Therefore this movement of the interferometric fringes can be used to sense the nanometric displacement of the micro-/nano-fiber induced by optical forces. Experimental results show that the resolutions of this method can reach 7.27nm/pixel for tilted angle 0.8o between the micro-/nano-fiber and substrate. It is concluded that the white light interferometry method is suitable for measuring the weak optical force.

  17. Fiber optic distributed temperature sensing for the determination of the nocturnal atmospheric boundary layer height

    OpenAIRE

    Keller, C A; H. Huwald; Vollmer, M.K.; Wenger, A.; Hill, M.; Parlange, M.B.; S. Reimann

    2011-01-01

    A new method for measuring air temperature profiles in the atmospheric boundary layer at high spatial and temporal resolution is presented. The measurements are based on Raman scattering distributed temperature sensing (DTS) with a fiber optic cable attached to a tethered balloon. These data were used to estimate the height of the stable nocturnal boundary layer. The experiment was successfully deployed during a two-day campaign in Septemb...

  18. Fiber optic vibration sensor

    Science.gov (United States)

    Dooley, Joseph B. (Harriman, TN); Muhs, Jeffrey D. (Lenoir City, TN); Tobin, Kenneth W. (Harriman, TN)

    1995-01-01

    A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity.

  19. Structural health monitoring of composite-based UAVs using simultaneous fiber optic interrogation by static Rayleigh-based distributed sensing and dynamic fiber Bragg grating point sensors

    Science.gov (United States)

    Tur, Moshe; Sovran, Ido; Bergman, Arik; Motil, Avi; Shapira, Osher; Ben-Simon, Uri; Kressel, Iddo

    2015-09-01

    Embedded fiber-optic strain sensing networks for airworthy assessment of operational Unmanned Aerial Vehicles (UAVs) are presented. Sensing is based on in-flight fiber Bragg grating technology, as well as on on-ground Rayleigh backscattering distributed strain sensing. While the in-flight instrumentation monitors loads, looking for excessive values, the Rayleigh-based technique is used for high spatial resolution strain distribution along the UAV wings, under prescribed loading. Consistency of measurements over time indicates structural integrity. Simultaneous strain measurements using both distributed Rayleigh and fiber Bragg gratings, on the same fiber, promises to combine high spatial resolution, though practically static measurements with dynamic, though discrete ones.

  20. Spectroscopic and fiber optic ethanol sensing properties Gd doped ZnO nanoparticles.

    Science.gov (United States)

    Noel, J L; Udayabhaskar, R; Renganathan, B; Muthu Mariappan, S; Sastikumar, D; Karthikeyan, B

    2014-11-11

    We report the structural, optical and gas sensing properties of prepared pure and Gd doped ZnO nanoparticles through solgel method at moderate temperature. Structural studies are carried out by X-ray diffraction method confirms hexagonal wurtzite structure and doping induced changes in lattice parameters is observed. Optical absorption spectral studies shows red shift in the absorption peak corresponds to band-gap from 3.42 eV to 3.05 eV and broad absorption in the visible range after Gd doping is observed. Scanning electron microscopic studies shows increase in particle size where the particle diameters increase from few nm to micrometers after Gd doping. The clad modified ethanol fiber-optic sensor studies for ethanol sensing exhibits best sensitivity for the 3% Gd doped ZnO nanoparticles and the sensitivity get lowered incase of higher percentage of Gd doped ZnO sample. PMID:24892544

  1. Distributed sensing of hydrocarbon leakage using fiber-optic time domain reflectometry

    International Nuclear Information System (INIS)

    In many industrial areas fast leakage detection and spill locating of environmentally hazardous substances in technical installations with large spatial extension, e.g., chemical plants, pipelines, tanks or waste deposits gains in importance. For a complete and continuous control of such sites distributed chemical sensing is essential. In this paper a new distributed sensor system for fast hydrocarbon leakage detection and localization is presented, which is based on hydrocarbon sensitive optical fibers and optical time domain reflectometry (OTDR). Depending on the used laser pulse width a minimum spatial resolution of 1-5 m is obtained, while the minimum response times are in the 15-30 s range. (orig.)

  2. Remote fiber-optic chemical sensing using evanescent-wave interactions in chalcogenide glass fibers.

    Science.gov (United States)

    Heo, J; Rodrigues, M; Saggese, S J; Sigel, G H

    1991-09-20

    An infrared-transmitting chalcogenide fiber was used as an optical probe to analyze qualitatively and quantitatively various chemical substances in aqueous solutions. An unclad fiber with 380-microm diameter was combined with a Fourier transform infrared spectrometer to monitor the concentration of the analytes in solutions by measuring the changes in the absorbance of their fundamental vibration peaks. A linear relationship was observed between the absorption by the vanescent field and concentrations of various analytes. For this study low concentrations of acetone, ethyl alcohol, and sulfuric acid were detected in aqueous solutions. The minimum detection limit for these three chemical substances was 5, 3, and 2 vol. %, respectively, with a sensor length of 15 cm. It was also demonstrated that the same sensor design is capable of monitoring gaseous species such as dichlorodifluoromethane. PMID:20706486

  3. A Self-Referencing Intensity-Based Fiber Optic Sensor with Multipoint Sensing Characteristics

    Directory of Open Access Journals (Sweden)

    Sang-Jin Choi

    2014-07-01

    Full Text Available A self-referencing, intensity-based fiber optic sensor (FOS is proposed and demonstrated. The theoretical analysis for the proposed design is given, and the validity of the theoretical analysis is confirmed via experiments. We define the measurement parameter, X, and the calibration factor, ?, to find the transfer function, , of the intensity-based FOS head. The self-referencing and multipoint sensing characteristics of the proposed system are validated by showing the measured  and relative error versus the optical power attenuation of the sensor head for four cases: optical source fluctuation, various remote sensing point distances, fiber Bragg gratings (FBGs with different characteristics, and multiple sensor heads with cascade and/or parallel forms. The power-budget analysis and limitations of the measurement rates are discussed, and the measurement results of fiber-reinforced plastic (FRP coupon strain using the proposed FOS are given as an actual measurement. The proposed FOS has several benefits, including a self-referencing characteristic, the flexibility to determine FBGs, and a simple structure in terms of the number of devices and measuring procedure.

  4. A hybrid fiber-optic sensing system for down-hole pressure and distributed temperature measurements

    Science.gov (United States)

    Chen, Ke; Zhou, Xinlei; Yang, Bokai; Peng, Wei; Yu, Qingxu

    2015-10-01

    A hybrid fiber-optic sensing technique, combining the extrinsic Fabry-Perot interferometer (EFPI) based pressure sensor with the incoherent optical frequency domain reflectometry (IOFDR) based distributed temperature sensor (DTS), is presented for down-hole measurements. By using a laser diode as the common light source, a highly integrated hybrid EFPI/DTS sensing system has been developed with a single fiber. With the injection current of the laser diode below lasing threshold, the broadband spontaneous emission light is used for EFPI based pressure sensing; while with the injection current above the threshold, the stimulated emission light is used for Raman based distributed temperature sensing. There is no overlap between the spectral range of the reflected light from the EFPI sensor and the spectral range of the Raman scattered light. Pressure and distributed temperature can thus be measured by using wavelength-division multiplexing (WDM) technology. Experimental results show that both the pressure and the distributed temperature are measured with little interference. Furthermore, the pressure measurement can be compensated by the measured temperature values.

  5. E-Beam Patterned Gold Nanodot Arrays on Optical Fiber Tips for Localized Surface Plasmon Resonance Biochemical Sensing

    Directory of Open Access Journals (Sweden)

    Yongbin Lin

    2010-10-01

    Full Text Available Electron beam lithography (EBL was used to directly pattern periodic gold nanodot arrays on optical fiber tips. Localized surface plasmon resonance of the E-beam patterned gold nanodot arrays on optical fiber tips was utilized for biochemical sensing. The advantage of the optical fiber based localized surface plasmon resonance (LSPR sensors is the convenience to work with and work in harsh environments. An optical fiber tip LSPR refractive index sensor of 196 nm per refractive index unit (RIU sensitivity has been demonstrated. The affinity sensing property of the fiber tip sensor was demonstrated using biotin/streptavidin as the receptor/analyte. The detection limit for streptavidin was determined to be 6 pM.

  6. Double-Ended Calibration of Fiber-Optic Raman Spectra Distributed Temperature Sensing Data

    Directory of Open Access Journals (Sweden)

    John Selker

    2012-04-01

    Full Text Available Over the past five years, Distributed Temperature Sensing (DTS along fiber optic cables using Raman backscattering has become an important tool in the environmental sciences. Many environmental applications of DTS demand very accurate temperature measurements, with typical RMSE < 0.1 K. The aim of this paper is to describe and clarify the advantages and disadvantages of double-ended calibration to achieve such accuracy under field conditions. By measuring backscatter from both ends of the fiber optic cable, one can redress the effects of differential attenuation, as caused by bends, splices, and connectors. The methodological principles behind the double-ended calibration are presented, together with a set of practical considerations for field deployment. The results from a field experiment are presented, which show that with double-ended calibration good accuracies can be attained in the field.

  7. Application of optical fiber sensing technique to fast breeder reactor plants

    International Nuclear Information System (INIS)

    Optical fiber thermometers have some characteristics such as non-induction for electromagnetic interference noises, capability of measuring continuous temperature distribution ranging to even some km along the fiber by differing from conventional electric spot-type sensors such as thermocouple, and so on, so it can be expected to largely contribute to safety and reliability from viewpoints of monitoring and maintenance of plants, by applying the characteristics to temperature measurements of apparatuses and pipings in a fast breeder reactor (FBR) plant. As temperature measuring technology using optical fibers is already practiced at fire detection of buildings, tunnels, and so on, because of increasing transmission loss based on effects of radiation when using at nuclear reactor plants, it is important to adequately compensate this increase. Here was introduced an R and D result to make practice on temperature and radiation measuring methods at radiation environment, by applying optical fiber sensing technique to the fast breeder test-reactor, 'Joyo' of a sodium cooling-type FBR of JNC. (G.K.)

  8. Study of sensing properties and contrastive analysis of metal coating optical fiber grating

    Science.gov (United States)

    Wang, Jing; Wang, Ning; Shi, Bin; Sui, Qingmei; Guan, Congsheng; Wei, Guangqing; Li, Shuhua

    2014-02-01

    Optical fiber grating (FBG) has been widely used in the measurement of parameters such as temperature and strain. However, FBG is too slim to broken, whose outside protective layer tends to shedding easily, and it is also hard to change the temperature and strain sensitivity. In order to overcome the above disadvantages and to further expand the application range of FBG, this paper improves the technology of fiber grating metal film plating process firstly. It adopts a compositive method including chemical plating and electroplating to gild FBG, copper FBG and galvanize FBG, which all get good metal coating. Then, the temperature and strain sensing properties of metalized FBG is studied in detail. Multiple metal coating FBGs were put in high-low temperature test-box together, and then the test-box worked continuously at the temperature range of 0°C?95°C. After several experiments, it concludes that metal plating enhances the temperature sensitivity of fiber grating, and the one with galvanization has the highest temperature sensitivity of 0.0235. At last, FBGs with various cladding were pasted on carbon fiber cantilever beam respectively and the pressure on the top of the cantilever increased gradually. The experimental results show that wavelength of fiber grating shift toward the long wavelength with the increase of the pressure, and the one with galvanization has the maximum strain sensitivity which has minimal impact on fiber properties.

  9. Fiber optic detector

    Energy Technology Data Exchange (ETDEWEB)

    Partin, J.K.; Ward, T.E.; Grey, A.E.

    1990-12-31

    This invention is comprised of a portable fiber optic detector that senses the presence of specific target chemicals by exchanging the target chemical for a fluorescently-tagged antigen that is bound to an antibody which is in turn attached to an optical fiber. Replacing the fluorescently-tagged antigen reduces the fluorescence so that a photon sensing detector records the reduced light level and activates an appropriate alarm or indicator.

  10. An Implantable Neural Sensing Microsystem with Fiber-Optic Data Transmission and Power Delivery

    Directory of Open Access Journals (Sweden)

    Yoon-Kyu Song

    2013-05-01

    Full Text Available We have developed a prototype cortical neural sensing microsystem for brain implantable neuroengineering applications. Its key feature is that both the transmission of broadband, multichannel neural data and power required for the embedded microelectronics are provided by optical fiber access. The fiber-optic system is aimed at enabling neural recording from rodents and primates by converting cortical signals to a digital stream of infrared light pulses. In the full microsystem whose performance is summarized in this paper, an analog-to-digital converter and a low power digital controller IC have been integrated with a low threshold, semiconductor laser to extract the digitized neural signals optically from the implantable unit. The microsystem also acquires electrical power and synchronization clocks via optical fibers from an external laser by using a highly efficient photovoltaic cell on board. The implantable unit employs a flexible polymer substrate to integrate analog and digital microelectronics and on-chip optoelectronic components, while adapting to the anatomical and physiological constraints of the environment. A low power analog CMOS chip, which includes preamplifier and multiplexing circuitry, is directly flip-chip bonded to the microelectrode array to form the cortical neurosensor device.

  11. Design and Fabrication of Fiber-Optic Nanoprobes for Optical Sensing

    Directory of Open Access Journals (Sweden)

    Zhang Yan

    2011-01-01

    Full Text Available Abstract This paper describes the design and fabrication of fiber-optic nanoprobes developed for optical detection in single living cells. It is critical to fabricate probes with well-controlled nanoapertures for optimized spatial resolution and optical transmission. The detection sensitivity of fiber-optic nanoprobe depends mainly on the extremely small excitation volume that is determined by the aperture sizes and penetration depths. We investigate the angle dependence of the aperture in shadow evaporation of the metal coating onto the tip wall. It was found that nanoaperture diameters of approximately 50 nm can be achieved using a 25° tilt angle. On the other hand, the aperture size is sensitive to the subtle change of the metal evaporation angle and could be blocked by irregular metal grains. Through focused ion beam (FIB milling, optical nanoprobes with well-defined aperture size as small as 200 nm can be obtained. Finally, we illustrate the use of the nanoprobes by detecting a fluorescent species, benzo[a]pyrene tetrol (BPT, in single living cells. A quantitative estimation of the numbers of BPT molecules detected using fiber-optic nanoprobes for BPT solutions shows that the limit of detection was approximately 100 molecules.

  12. Optical Fiber Networks for Remote Fiber Optic Sensors

    OpenAIRE

    Montserrat Fernandez-Vallejo; Manuel Lopez-Amo

    2012-01-01

    This paper presents an overview of optical fiber sensor networks for remote sensing. Firstly, the state of the art of remote fiber sensor systems has been considered. We have summarized the great evolution of these systems in recent years; this progress confirms that fiber-optic remote sensing is a promising technology with a wide field of practical applications. Afterwards, the most representative remote fiber-optic sensor systems are briefly explained, discussing their schemes, challenges, ...

  13. Multipoint vibration sensing using fiber Bragg gratings and optical frequency domain reflectometry.

    Science.gov (United States)

    Wada, Atsushi; Tanaka, Satoshi; Takahashi, Nobuaki

    2015-07-01

    We present multipoint vibration sensing using fiber Bragg gratings and optical frequency domain refrectometry (OFDR). In OFDR based method, the maximum number of arrayed sensor can be few thousands and the measurement time is determined by wavelength scanning rate of a light source. In our sensor system, a laser diode is used as a wavelength scanning light source. Lasing wavelength of a laser diode can be modulated by changing its injection current. The injection current can be precisely modulated at high frequency up to 100 kHz using a laser-diode controller and wavelength scanning can be then easily achieved with a laser diode.

  14. Optical sensing elements for nitrogen dioxide (NO.sub.2) gas detection, a sol-gel method for making the sensing elements and fiber optic sensors incorporating nitrogen dioxide gas optical sensing elements

    Science.gov (United States)

    Mechery, Shelly John (Mississippi State, MS); Singh, Jagdish P. (Starkville, MS)

    2007-07-03

    A sensing element, a method of making a sensing element, and a fiber optic sensor incorporating the sensing element are described. The sensor can be used for the quantitative detection of NO.sub.2 in a mixture of gases. The sensing element can be made by incorporating a diazotizing reagent which reacts with nitrous ions to produce a diazo compound and a coupling reagent which couples with the diazo compound to produce an azo dye into a sol and allowing the sol to form an optically transparent gel. The sensing element changes color in the presence of NO.sub.2 gas. The temporal response of the absorption spectrum at various NO.sub.2 concentrations has also been recorded and analyzed. Sensors having different design configurations are described. The sensing element can detect NO.sub.2 gas at levels of parts per billion.

  15. Fiber bragg gratings in polymer optical fibers

    OpenAIRE

    Harbach, Nico Gérard

    2008-01-01

    Polymer optical fibers (POF) have received increased attention in recent years in the fields of data communication and sensing applications. The lower cost and higher flexibility are the main advantages of POF compared to silica fibers and make them interesting candidates for Fiber Bragg grating (FBG) sensor applications. FBG are convenient measurement devices for strain and temperature measurements, as they can be multiplexed within one fiber yielding a sensor array and the fiber can be embe...

  16. Nanocrystalline diamond microelectrode on fused silica optical fibers for electrochemical and optical sensing

    Science.gov (United States)

    Bogdanowicz, Robert; Sobaszek, Micha?; Ficek, Mateusz; Gnyba, Marcin; Ryl, Jacek; Siuzdak, Katarzyna; ?mietana, Mateusz

    2015-07-01

    Fabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrode on fused silica single mode optical fiber has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ºC. We have obtained homogenous, continuous and polycrystalline surface morphology with the mean grain size in the range of 100-250 nm and high sp3 content in B-NCD films. The films deposited on glass reference samples exhibit high refractive index (n?2.05 at ?=550 nm) and low extinction coefficient. Furthermore, cyclic voltammograms (CV) were recorded to determine the electrochemical window and reaction reversibility at the B-NCD fibre-based electrode. Cyclic voltammetry (CV) measurements in aqueous media consisting of 5mM K3[Fe(CN)6] in 0.1M Na2SO4 demonstrated a width of the electrochemical window up to 2.5 V and relatively fast kinetics expressed by a redox peak splitting below 500 mV. Moreover, thanks to high-n B-NCD overlay, the coated fibers can be also used for enhancing sensitivity of long-period gratings (LPGs) induced in the fibers. The LPG is capable for measuring variations in refractive index of surrounding liquid by tracing shift in resonance appearing in transmitted spectrum. Possible combined CV and LPG-based measurements are discussed in this work.

  17. Changes in speckle patterns induced by load application onto an optical fiber and its possible application for sensing purpose

    Science.gov (United States)

    Hasegawa, Makoto; Okumura, Jyun-ya; Hyuga, Akio

    2015-08-01

    Speckle patterns to be observed in an output light spot from an optical fiber are known to be changed due to external disturbances applied onto the optical fiber. In order to investigate possibilities of utilizing such changes in speckle patterns for sensing application, a certain load was applied onto a jacket-covered communication-grade multi-mode glass optical fiber through which laser beams emitted from a laser diode were propagating, and observed changes in speckle patterns in the output light spot from the optical fiber were investigated both as image data via a CCD camera and as an output voltage from a photovoltaic panel irradiated with the output light spot. The load was applied via a load application mechanism in which several ridges were provided onto opposite flat plates and a certain number of weights were placed there so that corrugated bending of the optical fiber was intentionally induced via load application due to the ridges. The obtained results showed that the number of speckles in the observed pattern in the output light spot as well as the output voltage from the photovoltaic panel irradiated with the output light spot showed decreases upon load application with relatively satisfactory repeatability. When the load was reduced, i.e., the weights were removed, the number of speckles then showed recovery. These results indicate there is a certain possibility of utilizing changes in speckle patterns for sensing of load application onto the optical fiber.

  18. Cryogenic Liquid Level-Sensing using Fiber-Optic Strain Sensor (FOSS) Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Armstrong innovators have developed a highly accurate method for measuring liquid levels using optical fibers. Unlike liquid level gauges that rely on discrete...

  19. In-situ strain sensing with fiber optic sensors embedded into stainless steel 316

    Science.gov (United States)

    Havermann, Dirk; Mathew, Jinesh; Macpherson, William N.; Maier, Robert R. J.; Hand, Duncan P.

    2015-04-01

    Fiber Bragg Grating (FBG) sensors are embedded into Stainless Steel (SS) 316 components using bespoke Selective Laser Melting (SLM) technology. SS 316 material is added on substrates by SLM, incorporating U-shaped grooves with dimensions suitable to hold nickel coated optical fibers. Coated optical fibers containing fiber Bragg gratings for strain monitoring are placed in the groove. Melting subsequent powder layer on top of the fiber completes the embedding. Strain levels exceeding 3 m? are applied to specimens and are measured by embedded fiber optic sensors. Elastic deformation of the steel component is reliably measured by the Bragg grating from within the component with high accuracy. During plastic deformation of the steel the optical fiber is slipping due to poor adhesive bonding between fused silica and metal surround.

  20. Fiber optic distributed temperature sensing for the determination of the nocturnal atmospheric boundary layer height

    Directory of Open Access Journals (Sweden)

    C. A. Keller

    2011-02-01

    Full Text Available A new method for measuring air temperature profiles in the atmospheric boundary layer at high spatial and temporal resolution is presented. The measurements are based on Raman scattering distributed temperature sensing (DTS with a fiber optic cable attached to a tethered balloon. These data were used to estimate the height of the stable nocturnal boundary layer. The experiment was successfully deployed during a two-day campaign in September 2009, providing evidence that DTS is well suited for this atmospheric application. Observed stable temperature profiles exhibit an exponential shape confirming similarity concepts of the temperature inversion close to the surface. The atmospheric mixing height (MH was estimated to vary between 5 m and 50 m as a result of the nocturnal boundary layer evolution. This value is in good agreement with the MH derived from concurrent Radon-222 (222Rn measurements and in previous studies.

  1. Fiber optic distributed temperature sensing for the determination of the nocturnal atmospheric boundary layer height

    Directory of Open Access Journals (Sweden)

    C. A. Keller

    2010-06-01

    Full Text Available A new method for measuring air temperature profiles in the atmospheric boundary layer at high spatial and temporal resolution is presented. The measurements are based on Raman scattering distributed temperature sensing (DTS with a fiber optic cable attached to a tethered balloon. These data were used to estimate the height of the stable nocturnal boundary layer. The experiment was successfully deployed during a two-day campaign in September 2009, providing evidence that DTS is well suited for this atmospheric application. Observed stable temperature profiles exhibit an exponential shape confirming similarity concepts of the temperature inversion close to the surface. The atmospheric mixing height (MH was estimated to vary between 5 m and 50 m as a result of the nocturnal boundary layer evolution. This value is in good agreement to the MH derived from concurrent Radon-222 (222Rn measurements and in previous studies.

  2. A Fourier domain mode-locked fiber laser based on dual-pump fiber optical parametric amplification and its application for a sensing system

    International Nuclear Information System (INIS)

    A Fourier domain mode-locked (FDML) fiber laser based on dual-pump fiber optical parametric amplification (FOPA) is proposed and demonstrated. The output spectrum of the proposed FDML fiber laser covers a sweeping wavelength range from 1540.8 to 1559.8 nm with a sweeping frequency of 31.688 kHz. A comparison of two FDML fiber lasers which are based on dual-pump FOPA and one-pump FOPA is also presented. A novel sensing system based on the FDML laser and a fiber Bragg grating, by which the sensing signal can be measured in the time domain instead of the frequency domain, is also demonstrated. (paper)

  3. Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Gregory L. Baker; Ruby N. Ghosh; D. J. Osborn; Po Zhang

    2006-09-30

    A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications has been developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. We report on a fiber optic technique for detection of gas phase oxygen up to 100 C based on the {sup 3}O{sub 2} quenching of the luminescence from molybdenum chloride clusters, K{sub 2}Mo{sub 6}Cl{sub 14}. The inorganic sensing film is a composite of sol-gel particles embedded in a thin, oxygen permeable sol-gel binder. The particles are comprised of thermally stable, luminescent K{sub 2}Mo{sub 6}Cl{sub 14} clusters dispersed in a fully equilibrated sol-gel matrix. From 40 to 100 C, the fiber sensor switches {approx}6x in intensity in response to alternating pulses of <0.001% O2 and 21% O{sub 2} between two well defined levels with a response time of 10 s. The sensor signal is a few nW for an input pump power of 250 {micro}W. The normalized sensor signal is linear with molar oxygen concentration and fits the theoretical Stern-Volmer relationship. Although the sensitivity decreases with temperature, sensitivity at 100 C is 160 [O{sub 2}]{sup -1}. These parameters are well suited for in-situ, real-time monitoring of oxygen for industrial process control applications.

  4. A Finite Element Analysis of Fiber Optic Acoustic Sensing Mandrel for Acoustic pressure with Increased Sensitivity

    Directory of Open Access Journals (Sweden)

    Prashil M. Junghare

    2013-09-01

    Full Text Available - This paper investigates the influence of material properties on the performance of an optical fiber wound mandrel composite fiber optic interferometer mandrel by using the ANSYS Cad tool, The acoustic sensitivity of an optical fiber considered analytically, High sensitivity obtained with low young modulus, very thick polymer coatings. The thick coating realized by embedding optical fiber in polyurethane. A flexible composite fiber-optic interferometric acoustic sensor has been developed by wrapping single mode fiber in a winding manner and then embedding a fiber in a thin polyurethane layer. The acoustic sensitivity has to be found more in a frequency range of (2.5-5.0 KHz. In this paper we studied the structural and material properties of a mandrel sensor with foaming layer in such way to get the optimal performance. The sensor was found to be compatible with water. Also the performance of optical fiber is analytically verified using the MATLAB software. In this paper the design was simulated in ANSYS Cad Tool, to verify the sensitivity of the Optical Mach-Zehnder Interferometric Sensor for increased sensitivity. The main objective and focus of the above work is concentrated on choosing the optimal foaming layer material by varying the Young Modulus E to choose the perfect foaming material for implementing in the design of mandrel.

  5. Research on the feature extraction and pattern recognition of the distributed optical fiber sensing signal

    Science.gov (United States)

    Wang, Bingjie; Sun, Qi; Pi, Shaohua; Wu, Hongyan

    2014-09-01

    In this paper, feature extraction and pattern recognition of the distributed optical fiber sensing signal have been studied. We adopt Mel-Frequency Cepstral Coefficient (MFCC) feature extraction, wavelet packet energy feature extraction and wavelet packet Shannon entropy feature extraction methods to obtain sensing signals (such as speak, wind, thunder and rain signals, etc.) characteristic vectors respectively, and then perform pattern recognition via RBF neural network. Performances of these three feature extraction methods are compared according to the results. We choose MFCC characteristic vector to be 12-dimensional. For wavelet packet feature extraction, signals are decomposed into six layers by Daubechies wavelet packet transform, in which 64 frequency constituents as characteristic vector are respectively extracted. In the process of pattern recognition, the value of diffusion coefficient is introduced to increase the recognition accuracy, while keeping the samples for testing algorithm the same. Recognition results show that wavelet packet Shannon entropy feature extraction method yields the best recognition accuracy which is up to 97%; the performance of 12-dimensional MFCC feature extraction method is less satisfactory; the performance of wavelet packet energy feature extraction method is the worst.

  6. Cardiac-induced localized thoracic motion detected by a fiber optic sensing scheme

    Science.gov (United States)

    Allsop, Thomas; Lloyd, Glynn; Bhamber, Ranjeet S.; Hadzievski, Ljupco; Halliday, Michael; Webb, David J.; Bennion, Ian

    2014-11-01

    The cardiovascular health of the human population is a major concern for medical clinicians, with cardiovascular diseases responsible for 48% of all deaths worldwide, according to the World Health Organization. The development of new diagnostic tools that are practicable and economical to scrutinize the cardiovascular health of humans is a major driver for clinicians. We offer a new technique to obtain seismocardiographic signals up to 54 Hz covering both ballistocardiography (below 20 Hz) and audible heart sounds (20 Hz upward), using a system based on curvature sensors formed from fiber optic long period gratings. This system can visualize the real-time three-dimensional (3-D) mechanical motion of the heart by using the data from the sensing array in conjunction with a bespoke 3-D shape reconstruction algorithm. Visualization is demonstrated by adhering three to four sensors on the outside of the thorax and in close proximity to the apex of the heart; the sensing scheme revealed a complex motion of the heart wall next to the apex region of the heart. The detection scheme is low-cost, portable, easily operated and has the potential for ambulatory applications.

  7. SPR based fiber optic sensor for refractive index sensing with enhanced detection accuracy and figure of merit in visible region

    Science.gov (United States)

    Mishra, Akhilesh K.; Mishra, Satyendra K.; Gupta, Banshi D.

    2015-06-01

    We, theoretically, propose a surface plasmon resonance (SPR) based indium tin oxide (ITO)-silver (Ag) coated fiber optic sensing probe for refractive index sensing in visible regime of the electromagnetic spectrum. A comparative study of ITO+Ag coated probe with Ag coated probe and with ITO coated probe using their respective optimized film thicknesses is carried out. We show that the proposed probe is endowed with the better sensitivity characteristic of ITO and better detection accuracy (DA) characteristic of Ag, and can sense change in refractive index with enhanced DA and figure of merit (FOM) in the visible region.

  8. Interrogation technique for a fiber Bragg grating sensing array based on a Sagnac interferometer and an acousto-optic modulator.

    Science.gov (United States)

    Zhou, Bin; Guan, Zuguang; Yan, Chunsheng; He, Sailing

    2008-11-01

    We propose and experimentally demonstrate a novel real-time interrogation technique for a fiber Bragg grating (FBG) sensing system that is based on a frequency-shifted asymmetric Sagnac interferometer. FBG sensors are connected to the Sagnac loop by an optical coupler, and an acousto-optic modulator (AOM) is asymmetrically placed in the Sagnac loop. By linearly sweeping the driving frequency of the AOM, the environmental variation around each FBG sensor can be determined by measuring the spectrum of the interference signals of the two counterpropagating light beams reflected by the corresponding FBG. The system has the advantages of low cost and real-time sensing. PMID:18978895

  9. Fiber-Optic Shape Sensing for Intelligent Solar Sail Deployment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna Innovations proposes to develop a distributed fiber-optic shape sensor to provide a control system for the deployment of ultra-lightweight inflatable support...

  10. 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,...

  11. Reflectance response of tapered optical fiber coated with graphene oxide nanostructured thin film for aqueous ethanol sensing

    Science.gov (United States)

    Shabaneh, A. A.; Girei, S. H.; Arasu, P. T.; Rahman, W. B. W. A.; Bakar, A. A. A.; Sadek, A. Z.; Lim, H. N.; Huang, N. M.; Yaacob, M. H.

    2014-11-01

    In this work, optical sensing performance of tapered multimode fiber tip coated with graphene oxide (GO) nanostructured thin film towards aqueous ethanol with different concentrations is investigated. The tapering process of the optical fiber is done by a glass processing machine. The multimode optical fiber tip is dip-coated with GO and annealed at 70 °C to enhance the binding of the nanomaterials to the silica fiber. FESEM, Raman microscopy and XRD analyses are performed to micro-characterize the GO thin films. The morphology of the GO is observed to be in sheets forms. The reflectance response of the GO coated fiber tip is compared with the uncoated tip. The measurements are taken using a spectrophotometer in the optical wavelength range of 550-720 nm. The reflectance response of the GO coated fiber tip reduced proportionally, upon exposure to ethanol with concentration range of 5-80%. The dynamic response of the developed sensor showed strong reversibility and repeatability when it is exposed to ethanol with concentrations of 5%, 20% and 40% in distilled water. At room temperature, the sensor shows fast response and recovery as low as 19 and 25 s, respectively.

  12. Combined imaging and chemical sensing using a single optical imaging fiber.

    Science.gov (United States)

    Bronk, K S; Michael, K L; Pantano, P; Walt, D R

    1995-09-01

    Despite many innovations and developments in the field of fiber-optic chemical sensors, optical fibers have not been employed to both view a sample and concurrently detect an analyte of interest. While chemical sensors employing a single optical fiber or a noncoherent fiberoptic bundle have been applied to a wide variety of analytical determinations, they cannot be used for imaging. Similarly, coherent imaging fibers have been employed only for their originally intended purpose, image transmission. We herein report a new technique for viewing a sample and measuring surface chemical concentrations that employs a coherent imaging fiber. The method is based on the deposition of a thin, analyte-sensitive polymer layer on the distal surface of a 350-microns-diameter imaging fiber. We present results from a pH sensor array and an acetylcholine biosensor array, each of which contains approximately 6000 optical sensors. The acetylcholine biosensor has a detection limit of 35 microM and a fast (fibers can display visual information of a remote sample with 4-microns spatial resolution, allowing for alternating acquisition of both chemical analysis and visual histology. PMID:8779411

  13. Fiber Optic Sensors and Sensor Networks Using a Time-domain Sensing Scheme

    OpenAIRE

    Chuji Wang; Malik Kaya; Peeyush Sahay; Haifa Alali; Robert Reese

    2013-01-01

    Fiber loop ringdown (FLRD) has demonstrated to be capable of sensing various quantities, such as chemical species, pressure, refractive index, strain, temperature, etc.; and it has high potential for the development of a sensor network. In the present work, we describe design and development of three different types of FLRD sensors for water, cracks, and temperature sensing in concrete structures. All of the three aforementioned sensors were indigenously developed very recently in our labora...

  14. FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS

    International Nuclear Information System (INIS)

    A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications is being developed. The sensor is based on the 3O2 quenching of the red emission from hexanuclear molybdenum chloride clusters. High temperature measurements of the emission of clusters in sol gel films show that the luminescence intensity from the films follow a 1/T relationship from room temperature to 150 C, and then declines at a slower rate at higher temperatures. The large number of photons available at 230 C is consistent with simple low cost optics for fiber optic probes based on the emission from clusters in sol gel films

  15. Optical fiber tactile sensor

    Science.gov (United States)

    Bejczy, A. K. (inventor)

    1983-01-01

    A tactile sensor comprises an array of cells which are covered by an elastic membrane, having an exposed surface which is adapted to come in contact with an object. Light is conducted to each cell from a light source by an optical fiber which terminates at the cell. Reflected light from the cell is conducted by an optical fiber to a light processor, which senses changes in the light received thereby from an ambient level whenever an object comes in contact with the membrane surface above the cell.

  16. Characterizing Groundwater Flowpaths with Fiber-Optic Distributed Temperature Sensing and Stable Isotopes

    Science.gov (United States)

    Peri, L.; Gryczkowski, L.; Zheng, Y.; Liu, J.; Wang, S.; Wu, B.; Yao, Y.; Huang, X.; Wei, H.; Liu, C.; Hu, Y.; Wu, X.; Yu, L.

    2012-12-01

    The Heihe River basin of Northern China experiences high demand for scarce water. The upper watershed consists of alpine mountains and glaciers while the lower watershed is the arid Gobi Desert. The middle basin is important for agriculture production and has an extensive network of irrigation canals that reduce flow in the Heihe River. The lower watershed therefore receives reduced flow which is impacting fragile desert environments. Sustainably managing water resources in the basin while allowing for continued agriculture requires enhanced understanding of watershed function and behavior. A hydrologic model is being developed of the middle basin to help address these issues. The identification of groundwater and surface water interactions is an important component for an accurate model. Fiber-optic Distributed Temperature Sensing (DTS) is being used in 2012 to help identify these processes. Stable isotope differences (deuterium and O-18) are also being used in areas of potential groundwater discharge identified by DTS to improve understanding of flowpaths within the watershed. This interactive study promotes future sustainable water resource management to restore desert ecosystems.

  17. A surface plasmon resonance probe without optical fibers as a portable sensing device

    International Nuclear Information System (INIS)

    A surface plasmon resonance (SPR) sensor integrating a small sensor probe, a laser emission diode, a photo detector, and a polarizer was developed as a portable sensing device. The sensor probe was made with a glass cylinder, 50 mm long and 1.5 mm in diameter, that was connected directly to a beam splitter without optical fibers. The SPR spectrum obtained with this probe system showed a 10% reflectivity minimum at 690 nm. Shifts of the SPR spectrum induced by refractive index (RI) changes in the sample were measured by detecting the reflection light intensity at 670 nm. When the sensitivity was compared using a BIAcoreTM SPR instrument, the lowest sensor response of 1 mV observed with the SPR probe system coincided with 1.4 x 10-6 of the RI changes. The RI resolution of the SPR probe was estimated with experimentally evaluated noise on the signal, and, consequently, it was concluded that the RI resolution was 1.2 x 10-5. Moreover, immunoreaction was demonstrated with adsorbed bovine serum albumin (BSA) and anti-BSA antibody as an analyte. As a result, 50 ng mL-1 of the lower detection limit was estimated

  18. Sub-cm Resolution Distributed Fiber Optic Hydrogen Sensing with Nano-Engineered TiO2

    CERN Document Server

    Poole, Zsolt; Yan, Aidong; Lin, Yuankun; Chen, Kevin

    2015-01-01

    The 3D nano-structuring on the 2) to be reduced and matched with the cladding of optical fiber(n~1.46) for low-loss integration. A high temperature capable hydrogen sensor composed of D-shaped optical fiber with palladium nanoparticles infused nanoporous (~5nm) TiO2 film is demonstrated. The behavior of the developed sensor was characterized by examining the wavelength of an incorporated Fiber Bragg Grating and by observing the transmission losses at temperatures up to 700C. In addition, with frequency domain reflectometry the distributed sensing potential of the developed sensor for hydrogen concentrations of up to 10% is examined. The results show the possibility of detecting chemical gradients with sub-cm resolution at very high temperatures(>500C).

  19. Sapphire ball lensed fiber probe for common-path optical coherence tomography in ocular imaging and sensing

    OpenAIRE

    Zhao, Mingtao; Yong HUANG; Kang, Jin U

    2013-01-01

    We describe a novel common-path optical coherence tomography (CP-OCT) fiber probe design using a sapphire ball lens for cross-sectional imaging and sensing in retina vitrectomy surgery. Single mode Gaussian beam (TEM00) simulation was used to optimize lateral resolution and working distance (WD) of the common-path probe. A theoretical sensitivity model for CP-OCT was prosed to assess its optimal performance based an unbalanced photodetector configuration. Two probe designs with working distan...

  20. Fiber optic monitoring device

    Science.gov (United States)

    Samborsky, James K. (605 Groves Blvd., N. Augusta, SC 29841)

    1993-01-01

    A device for the purpose of monitoring light transmissions in optical fibers comprises a fiber optic tap that optically diverts a fraction of a transmitted optical signal without disrupting the integrity of the signal. The diverted signal is carried, preferably by the fiber optic tap, to a lens or lens system that disperses the light over a solid angle that facilitates viewing. The dispersed light indicates whether or not the monitored optical fiber or system of optical fibers is currently transmitting optical information.

  1. Plasmonic nanocomposite thin film enabled fiber optic sensors for simultaneous gas and temperature sensing at extreme temperatures.

    Science.gov (United States)

    Ohodnicki, Paul R; Buric, Michael P; Brown, Thomas D; Matranga, Christopher; Wang, Congjun; Baltrus, John; Andio, Mark

    2013-10-01

    Embedded sensors capable of operation in extreme environments including high temperatures, high pressures, and highly reducing, oxidizing and/or corrosive environments can make a significant impact on enhanced efficiencies and reduced greenhouse gas emissions of current and future fossil-based power generation systems. Relevant technologies can also be leveraged in a wide range of other applications with similar needs including nuclear power generation, industrial process monitoring and control, and aviation/aerospace. Here we describe a novel approach to embedded sensing under extreme temperature conditions by integration of Au-nanoparticle based plasmonic nanocomposite thin films with optical fibers in an evanescent wave absorption spectroscopy configuration. Such sensors can potentially enable simultaneous temperature and gas sensing at temperatures approaching 900-1000 °C in a manner compatible with embedded and distributed sensing approaches. The approach is demonstrated using the Au/SiO2 system deposited on silica-based optical fibers. Stability of optical fibers under relevant high temperature conditions and interactions with changing ambient gas atmospheres is an area requiring additional investigation and development but the simplicity of the sensor design makes it potentially cost-effective and may offer a potential for widespread deployment. PMID:23948985

  2. Body-monitoring and health supervision by means of optical fiber-based sensing systems in medical textiles.

    Science.gov (United States)

    Quandt, Brit M; Scherer, Lukas J; Boesel, Luciano F; Wolf, Martin; Bona, Gian-Luca; Rossi, René M

    2015-02-18

    Long-term monitoring with optical fibers has moved into the focus of attention due to the applicability for medical measurements. Within this Review, setups of flexible, unobtrusive body-monitoring systems based on optical fibers and the respective measured vital parameters are in focus. Optical principles are discussed as well as the interaction of light with tissue. Optical fiber-based sensors that are already used in first trials are primarily selected for the section on possible applications. These medical textiles include the supervision of respiration, cardiac output, blood pressure, blood flow and its saturation with hemoglobin as well as oxygen, pressure, shear stress, mobility, gait, temperature, and electrolyte balance. The implementation of these sensor concepts prompts the development of wearable smart textiles. Thus, current sensing techniques and possibilities within photonic textiles are reviewed leading to multiparameter designs. Evaluation of these designs should show the great potential of optical fibers for the introduction into textiles especially due to the benefit of immunity to electromagnetic radiation. Still, further improvement of the signal-to-noise ratio is often necessary to develop a commercial monitoring system. PMID:25358557

  3. Directivity and Sensitivity of Fiber-Optic Cable Measuring Ground Motion using a Distributed Acoustic Sensing Array

    Science.gov (United States)

    Lancelle, C.; Lord, N. E.; Wang, H. F.; Fratta, D.; Nigbor, R. L.; Chalari, A.; Karaulanov, R.; Baldwin, J. A.; Castongia, E.

    2014-12-01

    Distributed acoustic sensing (DAS) is a relatively recent development for measurement of ground motion by using a fiber-optic cable itself as the sensor. In September 2013 a field test was conducted at the NEES@UCSB Garner Valley field site in Southern California incorporating DAS technology. A 762 meter long fiber-optic cable was trenched to a depth of about 0.3 m in a rectangular design with two interior diagonal segments. Existing instruments at the field site include the Garner Valley Downhole Array (GVDA) surface and borehole accelerometers and pore pressure transducers. A PASSCAL seismometer array and four NEES@UCLA tri-axial accelerometers were also deployed along the two interior diagonal segments. These sensors also recorded most of the source events. One goal of the field test was to study the response of the fiber-optic cable to various vibration sources, including a 45 kN shear shaker and a smaller 450 N portable mass shaker, both of which were available through NEES@UCLA. In addition to the shear sources, signals were recorded from a mini-Vibe source and hammer blows on a steel plate. The focus of this study is on the directivity and the sensitivity of the fiber-optic cable and the distributed acoustic sensor. Preliminary results indicate that the fiber-optic cable is most effective if oriented in the direction of maximum strain. Even with the directional response, signals were recorded throughout the array for different cable orientations at distances up to two-hundred meters. Move-out of different phases could be seen over several meters of traces recorded one-meter apart. Sensitivity of the fiber-optic cable relative to the other instruments is also presented.

  4. Infrared Fiber Optic Sensors

    Science.gov (United States)

    1997-01-01

    Successive years of Small Business Innovation Research (SBIR) contracts from Langley Research Center to Sensiv Inc., a joint venture between Foster-Miller Inc. and Isorad, Ltd., assisted in the creation of remote fiber optic sensing systems. NASA's SBIR interest in infrared, fiber optic sensor technology was geared to monitoring the curing cycles of advanced composite materials. These funds helped in the fabrication of an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. Foster-Miller ingenuity allowed infrared transmitting optical fibers to combine with Fourier Transform Infrared spectroscopy to enable remote sensing. Sensiv probes operate in the mid-infrared range of the spectrum, although modifications to the instrument also permits its use in the near-infrared region. The Sensiv needle-probe is built to be placed in a liquid or powder and analyze the chemicals in the mixture. Other applications of the probe system include food processing control; combustion control in furnaces; and maintenance problem solving.

  5. Advantage of multi-mode sapphire optical fiber for evanescent-field SERS sensing.

    Czech Academy of Sciences Publication Activity Database

    Chen, H.; Tian, F.; Chi, J.; Ka?ka, Ji?í; Du, H.

    2014-01-01

    Ro?. 39, ?. 20 (2014), 5822-5825. ISSN 0146-9592 R&D Projects: GA MŠk(CZ) LH11038 Institutional support: RVO:67985882 Keywords : Fiber optics sensors * Backscattering * Nanomaterials Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.292, year: 2014

  6. Advances in Using Fiber-Optic Distributed Temperature Sensing to Identify the Mixing of Waters

    Science.gov (United States)

    Briggs, M. A.; Day-Lewis, F. D.; Rosenberry, D. O.; Harvey, J. W.; Lane, J. W., Jr.; Hare, D. K.; Boutt, D. F.; Voytek, E. B.; Buckley, S.

    2014-12-01

    Fiber-optic distributed temperature sensing (FO-DTS) provides thermal data through space and time along linear cables. When installed along a streambed, FO-DTS can capture the influence of upwelling groundwater (GW) as thermal anomalies. The planning of labor-intensive physical measurements can make use of FO-DTS data to target areas of focused GW discharge that can disproportionately affect surface-water (SW) quality and temperature. Typical longitudinal FO-DTS spatial resolution ranges 0.25 to1.0 m, and cannot resolve small-scale water-column mixing or sub-surface diurnal fluctuations. However, configurations where the cable is wrapped around rods can improve the effective vertical resolution to sub-centimeter scales, and the pipes can be actively heated to induce a thermal tracer. Longitudinal streambed and high-resolution vertical arrays were deployed at the upper Delaware River (PA, USA) and the Quashnet River (MA, USA) for aquatic habitat studies. The resultant datasets exemplify the varied uses of FO-DTS. Cold anomalies found along the Delaware River steambed coincide with zones of known mussel populations, and high-resolution vertical array data showed relatively stable in-channel thermal refugia. Cold anomalies at the Quashnet River identified in 2013 were found to persist in 2014, and seepage measurements and water samples at these locations showed high GW flux with distinctive chemistry. Cable location is paramount to seepage identification, particularly in faster flowing deep streams such as the Quashnet and Delaware Rivers where steambed FO-DTS identified many seepage zones with no surface expression. The temporal characterization of seepage dynamics are unique to FO-DTS. However, data from Tidmarsh Farms, a cranberry bog restoration site in MA, USA indicate that in slower flowing shallow steams GW inflow affects surface temperature; therefore infrared imaging can provide seepage location information similar to FO-DTS with substantially less effort.

  7. Optical Fiber Chemical Sensor with Sol-Gel Derived Refractive Material as Transducer for High Temperature Gas Sensing in Clean Coal Technology

    Energy Technology Data Exchange (ETDEWEB)

    Shiquan Tao

    2006-12-31

    The chemistry of sol-gel derived silica and refractive metal oxide has been systematically studied. Sol-gel processes have been developed for preparing porous silica and semiconductor metal oxide materials. Micelle/reversed micelle techniques have been developed for preparing nanometer sized semiconductor metal oxides and noble metal particles. Techniques for doping metal ions, metal oxides and nanosized metal particles into porous sol-gel material have also been developed. Optical properties of sol-gel derived materials in ambient and high temperature gases have been studied by using fiber optic spectroscopic techniques, such as fiber optic ultraviolet/visible absorption spectrometry, fiber optic near infrared absorption spectrometry and fiber optic fluorescence spectrometry. Fiber optic spectrometric techniques have been developed for investigating the optical properties of these sol-gel derived materials prepared as porous optical fibers or as coatings on the surface of silica optical fibers. Optical and electron microscopic techniques have been used to observe the microstructure, such as pore size, pore shape, sensing agent distribution, of sol-gel derived material, as well as the size and morphology of nanometer metal particle doped in sol-gel derived porous silica, the nature of coating of sol-gel derived materials on silica optical fiber surface. In addition, the chemical reactions of metal ion, nanostructured semiconductor metal oxides and nanometer sized metal particles with gas components at room temperature and high temperatures have also been investigated with fiber optic spectrometric methods. Three classes of fiber optic sensors have been developed based on the thorough investigation of sol-gel chemistry and sol-gel derived materials. The first group of fiber optic sensors uses porous silica optical fibers doped with metal ions or metal oxide as transducers for sensing trace NH{sub 3} and H{sub 2}S in high temperature gas samples. The second group of fiber optic sensors uses sol-gel derived porous silica materials doped with nanometer particles of noble metals in the form of fiber or coating for sensing trace H{sub 2}, NH{sub 3} and HCl in gas samples at for applications ambient temperature. The third classes of fiber optic sensors use sol-gel derived semiconductor metal oxide coating on the surface of silica optical fiber as transducers for selectively sensing H{sub 2}, CH{sub 4} and CO at high temperature. In addition, optical fiber temperature sensors use the fluorescence signal of rare-earth metal ions doped porous silica optical fiber or the optical absorption signal of thermochromic metal oxide materials coated on the surface of silica optical fibers have also been developed for monitoring gas temperature of corrosive gas. Based on the results obtained from this project, the principle of fiber optic sensor techniques for monitoring matrix gas components as well as trace components of coal gasification derived syngas has been established. Prototype sensors for sensing trace ammonia and hydrogen sulfide in gasification derived syngas have been built up in our laboratory and have been tested using gas samples with matrix gas composition similar to that of gasification derived fuel gas. Test results illustrated the feasibility of these sensors for applications in IGCC processes.

  8. The fiber-optic gyroscope, a century after Sagnac's experiment: The ultimate rotation-sensing technology?

    Science.gov (United States)

    Lefèvre, Hervé C.

    2014-12-01

    Taking advantage of the development of optical-fiber communication technologies, the fiber-optic gyroscope (often abbreviated FOG) started to be investigated in the mid-1970s, opening the way for a fully solid-state rotation sensor. It was firstly seen as dedicated to medium-grade applications (1 ° / h range), but today, it reaches strategic-grade performance (10-4 ° / h range) and surpasses its well-established competitor, the ring-laser gyroscope, in terms of bias noise and long-term stability. Further progresses remain possible, the challenge being the ultimate inertial navigation performance of one nautical mile per month corresponding to a long-term bias stability of 10-5 ° / h. This paper is also the opportunity to recall the historical context of Sagnac's experiment, the origin of all optical gyros. xml:lang="fr"

  9. Fiber optic connector

    Science.gov (United States)

    Rajic, Slobodan (Knoxville, TN); Muhs, Jeffrey D. (Lenior City, TN)

    1996-01-01

    A fiber optic connector and method for connecting composite materials within which optical fibers are imbedded. The fiber optic connector includes a capillary tube for receiving optical fibers at opposing ends. The method involves inserting a first optical fiber into the capillary tube and imbedding the unit in the end of a softened composite material. The capillary tube is injected with a coupling medium which subsequently solidifies. The composite material is machined to a desired configuration. An external optical fiber is then inserted into the capillary tube after fluidizing the coupling medium, whereby the optical fibers are coupled.

  10. Behavior of Random Hole Optical Fibers under Gamma Ray Irradiation and Its Potential Use in Radiation Sensing Applications

    Directory of Open Access Journals (Sweden)

    Anbo Wang

    2007-05-01

    Full Text Available Effects of radiation on sensing and data transmission components are of greatinterest in many applications including homeland security, nuclear power generation, andmilitary. A new type of microstructured optical fiber (MOF called the random hole opticalfiber (RHOF has been recently developed. The RHOFs can be made in many differentforms by varying the core size and the size and extent of porosity in the cladding region.The fibers used in this study possessed an outer diameter of 110 μm and a core ofapproximately 20 μm. The fiber structure contains thousands of air holes surrounding thecore with sizes ranging from less than 100 nm to a few μm. We present the first study ofthe behavior of RHOF under gamma irradiation. We also propose, for the first time to ourknowledge, an ionizing radiation sensor system based on scintillation light from ascintillator phosphor embedded within a holey optical fiber structure. The RHOF radiationresponse was compared to normal single mode and multimode commercial fibers(germanium doped core, pure silica cladding and to those of radiation resistant fibers (puresilica core with fluorine doped cladding fibers. The comparison was done by measuringradiation-induced absorption (RIA in all fiber samples at the 1550 nm wavelength window(1545 ± 25 nm. The study was carried out under a high-intensity gamma ray field from a 60Co source (with an exposure rate of 4x104 rad/hr at an Oak Ridge National Laboratory gamma ray irradiation facility. Linear behavior, at dose values less than 106 rad, was observed in all fiber samples except in the pure silica core fluorine doped cladding fiber which showed RIA saturation at 0.01 dB. RHOF samples demonstrated low RIA (0.02 and 0.005 dB compared to standard germanium doped core pure silica cladding (SMF and MMF fibers. Results also showed the possibility of post-fabrication treatment to improve the radiation resistance of the RHOF fibers.

  11. Highly distributed multi-point, temperature and pressure compensated, fiber optic oxygen sensors (FOxSense) for aircraft fuel tank environment and safety monitoring

    Science.gov (United States)

    Mendoza, Edgar A.; Kempen, Cornelia; Sun, Sunjian; Esterkin, Yan

    2014-09-01

    This paper describes recent progress towards the development and qualification of a highly distributed, multi-point, all optical pressure and temperature compensated, fiber optic oxygen sensor (FOxSense™) system for closed-loop monitoring and safety of the oxygen ullage environment inside fuel tanks of military and commercial aircraft. The alloptical FOxSense™ system uses a passive, multi-parameter (O2/T&P) fiber optic sensor probe with no electrical connections leading to the sensors install within the fuel tanks of an aircraft. The all optical sensor consists of an integrated multi-parameter fiber optic sensor probe that integrates a fuel insensitive fluorescence based optical oxygen optrode with built-in temperature and pressure optical optrodes for compensation of temperature and pressure variants induced in the fluorescence response of the oxygen optrode. The distributed (O2/T&P) fiber optic sensors installed in the fuel tanks of the aircraft are connected to the FOxSense optoelectronic system via a fiber optic cable conduit reaching to each fuel tank in the aircraft. A multichannel frequency-domain fiber optic sensor read-out (FOxSense™) system is used to interrogate the optical signal of all three sensors in real-time and to display the fuel tank oxygen environment suitable for aircraft status and alarm applications. Preliminary testing of the all optical fiber optic oxygen sensor have demonstrated the ability to monitor the oxygen environment inside a simulated fuel tank in the range of 0% O2 to 40% O2 concentrations, temperatures from (-) 40°C to (+) 60°C, and altitudes from 0-ft to 40,000-ft.

  12. FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Gregory L. Baker; Ruby N. Ghosh; D.J. Osborn III; Po Zhang

    2005-04-01

    A reflection mode fiber optic oxygen sensor that can operate at high temperatures for power plant applications is being developed. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. One of the critical materials issues is to demonstrate that the luminescent cluster immobilized in the sol-gel porous support can withstand high temperature. At the same time the sol-gel matrix must have a high permeability to oxygen. Using a potassium salt of the molybdenum clusters, K{sub 2}Mo{sub 6}Cl{sub 14}, we have established the conditions necessary for deposition of optical quality sol-gel films. From spectroscopic measurements of the film we have shown that the cluster luminescence is stable following heat cycling of 54 hours at 200 C. Quenching of a factor of 1.5X between pure nitrogen and 21% oxygen was observed from in-situ measurements of films heated directly at 200 C. An automated system for characterizing fiber optic oxygen sensors up to 220 C with a temporal resolution better than 10 s is under construction. We estimate a signal of 6 x 10{sup 8} photons/s after complete quenching in 21% oxygen. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.

  13. Research on corrosion detection for steel reinforced concrete structures using the fiber optical white light interferometer sensing technique

    International Nuclear Information System (INIS)

    In this paper, a novel kind of steel rebar corrosion monitoring technique for steel reinforced concrete structures is proposed, designed, and tested. The technique is based on the fiber optical white light interferometer (WLI) sensing technique. Firstly, a feasibility test was carried out using an equal-strength beam for comparison of strain sensing ability between the WLI and a fiber Bragg grating (FBG). The comparison results showed that the sensitivity of the WLI is sufficient for corrosion expansion strain monitoring. Then, two WLI corrosion sensors (WLI-CSs) were designed, fabricated, and embedded into concrete specimens to monitor expansion strain caused by steel rebar corrosion. Their performance was studied in an accelerated electrochemical corrosion test. Experimental results show that expansion strain along the fiber optical coil winding area can be detected and measured accurately by the proposed sensor. The advantages of the proposed monitoring technique allow for quantitative corrosion expansion monitoring to be executed in real time for reinforced concrete structures and with low cost. (paper)

  14. 300 m optic fiber Bragg grating temperature sensing system for seawater measurement

    International Nuclear Information System (INIS)

    Optic fiber grating sensor is a research hotspot.It has been used on many occasions,and how to use it for ocean detection is a new research directions. The paper introduced the calibration work of FBG temperature sensors. It confirmed that from being armored package,the sensors can eliminate the water pressure effect. From the calibration experiment and data processing,60 sensors has little error were screened out for experiment. 300 m long optic fiber Bragg grating sensor array was designed.The marine experiments were achived in South China Sea with 300 meters long Bragg grating array and got the seawater profile temperature. Proposed the curve fitting method to process the data based on Levenberg-Marquardt algorithm. By curve fitting to the data acquired,the precision was better than 0.2 deg. C, which verified the effectiveness of the method.This result has practical value.

  15. Optical fibre sensing of plasmas

    International Nuclear Information System (INIS)

    The progress of optical fiber technology for communications has induced an interest in, among others, the sensing of a wide range of physical, and chemical quantities. Any application of optical fibers that are crucial for communication are significant for sensing, e.g. small dimension, insulating materials, immunity to high voltage field etc. In the present paper basic points of optical fiber sensing are summarized. It is noted optical fiber sensors come in two forms, intrinsic and extrinsic. In the former the fiber itself works as sensing element, in addition to data transmission lines. In an intrinsic sensor, a single fiber transmits the light from the source to the detector and the light is modulated while it is in the fiber. On the other hand, in the extrinsic sensor, the light leaves the input fiber to be modulated before being collected by the second output fiber. Characteristic of the light that can be modulated are amplitude, phase, polarization, and wavelength. The paper describes the modulation in some details. (author)

  16. Interferometric Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    Hae Young Choi

    2012-02-01

    Full Text Available Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  17. An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique

    International Nuclear Information System (INIS)

    In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 × 10?4 m3/s (18.0 l/min) for the mono-directional sensor and a measurement range of ±3.00 × 10?4 m3/s (±18.0 l/min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono-directional configuration, the coefficient of determination r2 is equal to 0.997; for the bi-directional configuration, the coefficient of determination r2 is equal to 0.990 for positive flows (inspiration) and 0.988 for negative flows (expiration). Measurement uncertainty ?Q of air flow rate has been evaluated by means of the propagation of distributions and the percentage error in the arrangement of bi-directional sensor ranges from a minimum of about 0.5% at ?18.0 l/min to a maximum of about 9% at ?12.0 l/min.

  18. An air flow sensor for neonatal mechanical ventilation applications based on a novel fiber-optic sensing technique.

    Science.gov (United States)

    Battista, L; Sciuto, S A; Scorza, A

    2013-03-01

    In this work, a simple and low-cost air flow sensor, based on a novel fiber-optic sensing technique has been developed for monitoring air flows rates supplied by a neonatal ventilator to support infants in intensive care units. The device is based on a fiber optic sensing technique allowing (a) the immunity to light intensity variations independent by measurand and (b) the reduction of typical shortcomings affecting all biomedical fields (electromagnetic interference and patient electrical safety). The sensing principle is based on the measurement of transversal displacement of an emitting fiber-optic cantilever due to action of air flow acting on it; the fiber tip displacement is measured by means of a photodiode linear array, placed in front of the entrance face of the emitting optical fiber in order to detect its light intensity profile. As the measurement system is based on a detection of the illumination pattern, and not on an intensity modulation technique, it results less sensitive to light intensity fluctuation independent by measurand than intensity-based sensors. The considered technique is here adopted in order to develop two different configurations for an air flow sensor suitable for the measurement of air flow rates typically occurring during mechanical ventilation of newborns: a mono-directional and a bi-directional transducer have been proposed. A mathematical model for the air flow sensor is here proposed and a static calibration of two different arrangements has been performed: a measurement range up to 3.00 × 10(-4) m(3)?s (18.0 l?min) for the mono-directional sensor and a measurement range of ±3.00 × 10(-4) m(3)?s (±18.0 l?min) for the bi-directional sensor are experimentally evaluated, according to the air flow rates normally encountered during tidal breathing of infants with a mass lower than 10 kg. Experimental data of static calibration result in accordance with the proposed theoretical model: for the mono-directional configuration, the coefficient of determination r(2) is equal to 0.997; for the bi-directional configuration, the coefficient of determination r(2) is equal to 0.990 for positive flows (inspiration) and 0.988 for negative flows (expiration). Measurement uncertainty ?Q of air flow rate has been evaluated by means of the propagation of distributions and the percentage error in the arrangement of bi-directional sensor ranges from a minimum of about 0.5% at -18.0 l?min to a maximum of about 9% at -12.0 l?min. PMID:23556844

  19. Optical Fiber Distributed Sensing Structural Health Monitoring (SHM) Strain Measurements Taken During Cryotank Y-Joint Test Article Load Cycling at Liquid Helium Temperatures

    Science.gov (United States)

    Allison, Sidney G.; Prosser, William H.; Hare, David A.; Moore, Thomas C.; Kenner, Winfred S.

    2007-01-01

    This paper outlines cryogenic Y-joint testing at Langley Research Center (LaRC) to validate the performance of optical fiber Bragg grating strain sensors for measuring strain at liquid helium temperature (-240 C). This testing also verified survivability of fiber sensors after experiencing 10 thermal cool-down, warm-up cycles and 400 limit load cycles. Graphite composite skins bonded to a honeycomb substrate in a sandwich configuration comprised the Y-joint specimens. To enable SHM of composite cryotanks for consideration to future spacecraft, a light-weight, durable monitoring technology is needed. The fiber optic distributed Bragg grating strain sensing system developed at LaRC is a viable substitute for conventional strain gauges which are not practical for SHM. This distributed sensing technology uses an Optical Frequency Domain Reflectometer (OFDR). This measurement approach has the advantage that it can measure hundreds of Bragg grating sensors per fiber and the sensors are all written at one frequency, greatly simplifying fiber manufacturing. Fiber optic strain measurements compared well to conventional strain gauge measurements obtained during these tests. These results demonstrated a high potential for a successful implementation of a SHM system incorporating LaRC's fiber optic sensing system on the composite cryotank and other future cryogenic applications.

  20. Fiber Singular Optics

    Directory of Open Access Journals (Sweden)

    A. V. Volyar

    2002-06-01

    Full Text Available The present review is devoted to the optical vortex behavior both in free space and optical fibers. The processes of the vortex transformations in perturbed optical fibers are analyzed on the base of the operator of the spin – orbit interaction in order to forecast the possible ways of manufacturing the vortex preserving fibers and their applications in supersensitive optical devices.

  1. Application of Fiber Optic Instrumentation

    Science.gov (United States)

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

    2012-01-01

    Fiber optic sensing technology has emerged in recent years offering tremendous advantages over conventional aircraft instrumentation systems. The advantages of fiber optic sensors over their conventional counterparts are well established; they are lighter, smaller, and can provide enormous numbers of measurements at a fraction of the total sensor weight. After a brief overview of conventional and fiber-optic sensing technology, this paper presents an overview of the research that has been conducted at NASA Dryden Flight Research Center in recent years to advance this promising new technology. Research and development areas include system and algorithm development, sensor characterization and attachment, and real-time experimentally-derived parameter monitoring for ground- and flight-based applications. The vision of fiber optic smart structure technology is presented and its potential benefits to aerospace vehicles throughout the lifecycle, from preliminary design to final retirement, are presented.

  2. Remote optical sensing on the nanometer scale with a bowtie aperture nano-antenna on a fiber tip of scanning near-field optical microscopy

    International Nuclear Information System (INIS)

    Plasmonic nano-antennas have proven the outstanding ability of sensing chemical and physical processes down to the nanometer scale. Sensing is usually achieved within the highly confined optical fields generated resonantly by the nano-antennas, i.e., in contact to the nanostructures. In this paper, we demonstrate the sensing capability of nano-antennas to their larger scale environment, well beyond their plasmonic confinement volume, leading to the concept of “remote” (non contact) sensing on the nanometer scale. On the basis of a bowtie-aperture nano-antenna (BNA) integrated at the apex of a SNOM (Scanning Near-field Optical Microscopy) fiber tip, we introduce an ultra-compact, moveable, and background-free optical nanosensor for the remote sensing of a silicon surface (up to distance of 300?nm). Sensitivity of the BNA to its large scale environment is high enough to expect the monitoring and control of the spacing between the nano-antenna and a silicon surface with sub-nanometer accuracy. This work paves the way towards an alternative class of nanopositioning techniques, based on the monitoring of diffraction-free plasmon resonance, that are alternative to nanomechanical and diffraction-limited optical interference-based devices

  3. Remote optical sensing on the nanometer scale with a bowtie aperture nano-antenna on a fiber tip of scanning near-field optical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Atie, Elie M.; Xie, Zhihua; El Eter, Ali; Salut, Roland; Baida, Fadi I.; Grosjean, Thierry, E-mail: thierry.grosjean@univ-fcomte.fr [Institut FEMTO-ST, UMR CNRS 6174, Université de Franche-Comté, Département d' Optique P.M. Duffieux, 15B avenue des Montboucons, 25030 Besançon cedex (France); Nedeljkovic, Dusan [Lovalite s.a.s., 7 rue Xavier Marmier, 25000 Besançon (France); Tannous, Tony [Department of Physics, University of Balamand, P.O. Box 100 Tripoli (Lebanon)

    2015-04-13

    Plasmonic nano-antennas have proven the outstanding ability of sensing chemical and physical processes down to the nanometer scale. Sensing is usually achieved within the highly confined optical fields generated resonantly by the nano-antennas, i.e., in contact to the nanostructures. In this paper, we demonstrate the sensing capability of nano-antennas to their larger scale environment, well beyond their plasmonic confinement volume, leading to the concept of “remote” (non contact) sensing on the nanometer scale. On the basis of a bowtie-aperture nano-antenna (BNA) integrated at the apex of a SNOM (Scanning Near-field Optical Microscopy) fiber tip, we introduce an ultra-compact, moveable, and background-free optical nanosensor for the remote sensing of a silicon surface (up to distance of 300?nm). Sensitivity of the BNA to its large scale environment is high enough to expect the monitoring and control of the spacing between the nano-antenna and a silicon surface with sub-nanometer accuracy. This work paves the way towards an alternative class of nanopositioning techniques, based on the monitoring of diffraction-free plasmon resonance, that are alternative to nanomechanical and diffraction-limited optical interference-based devices.

  4. 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)

  5. Fiber Optics Instrumentation Development

    Science.gov (United States)

    Chan, Patrick Hon Man; Parker, Allen R., Jr.; Richards, W. Lance

    2010-01-01

    This is a general presentation of fiber optics instrumentation development work being conducted at NASA Dryden for the past 10 years and recent achievements in the field of fiber optics strain sensors.

  6. Lamb wave-based damage detection of composite shells using high-speed fiber-optic sensing

    Science.gov (United States)

    Sotoudeh, Vahid; Black, Richard J.; Moslehi, Behzad; Qiao, Pizhong

    2014-04-01

    A Lamb wave-based damage identification method called damage imaging method for composite shells is presented. A damage index (DI) is generated from the delay matrix of the Lamb wave response signals, and it is used to indicate the location and approximate area of the damage. A piezoelectric actuator is employed to generate the Lamb waves that are subsequently captured by a fiber Bragg grating (FBG) sensor element array multiplexed in a single fiber connected to a high-speed fiber-optic sensor system. The high-speed sensing is enabled by an innovative parallel-architecture optical interrogation system. The viability of this method is demonstrated by analyzing the numerical and experimental Lamb wave response signals from laminated composite shells. The technique only requires the response signals from the plate after damage, and it is capable of performing near real-time damage identification. This study sheds some light on the application of a Lamb wave-based damage detection algorithm for curved plate/shell-type structures by using the relatively low frequency (around 100 kHz) Lamb wave response and the high-speed FBG sensor system.

  7. Fiber optic Brillouin distributed sensing using phase-shift keying modulation techniques

    Science.gov (United States)

    Stiller, Birgit; Lee, Min W.; Nguyen, Duc Minh; Hauden, Jerôme; Mottet, Alexandre; Maillotte, Hervé; Sylvestre, Thibaut

    2012-04-01

    In this work we demonstrate two new BOTDA sensing systems based on differential (DPSK) and quadrature (QPSK) phase-shift keying modulation techniques with enhanced performances. First we demonstrate Brillouin echoes distributed sensing (BEDS) with centimeter resolution using a single intensity DPSK modulator for the pump pulse. The optical ?-phase pulse is directly generated at the end of an intensity pulse using DPSK technique. This allows an easy adjustment of the delay between the intensity and phase pulse and improves the optical loss of the pump. The second technique uses an optical QPSK modulator (I & Q modulator) as a single sideband (SSB) modulator. The advantage of I & Q modulator compared to dual-drive modulator lies on the high performance of carrier suppression of 55 dB as well as side-mode suppression of 40 dB at 1535 nm. Besides the filter that chooses either the Stokes or anti-Stokes component before detecting the Brillouin response on the photodiode is no more needed. By use of the I & Q modulator the performance of BOTDA using either Stokes or anti-Stokes component is shown and discussed.

  8. Improvement of plastic optical fiber microphone based on moisture pattern sensing in devoiced breath

    Science.gov (United States)

    Taki, Tomohito; Honma, Satoshi; Morisawa, Masayuki; Muto, Shinzo

    2008-03-01

    Conversation is the most practical and common form in communication. However, people with a verbal handicap feel a difficulty to produce words due to variations in vocal chords. This research leads to develop a new devoiced microphone system based on distinguishes between the moisture patterns for each devoiced breaths, using a plastic optical fiber (POF) moisture sensor. In the experiment, five POF-type moisture sensors with fast response were fabricated by coating swell polymer with a slightly larger refractive index than that of fiber core and were set in front of mouth. When these sensors are exposed into humid air produced by devoiced breath, refractive index in cladding layer decreases by swelling and then the POF sensor heads change to guided type. Based on the above operation principle, the output light intensities from the five sensors set in front of mouth change each other. Using above mentioned output light intensity patterns, discernment of devoiced vowels in Japanese (a,i,u,e,o) was tried by means of DynamicProgramming-Matching (DP-matching) method. As the result, distinction rate over 90% was obtained to Japanese devoiced vowels. Therefore, using this system and a voice synthesizer, development of new microphone for the person with a functional disorder in the vocal chords seems to be possible.

  9. Multipoint Pressure and Temperature Sensing Fiber Optic Cable for Monitoring CO2 Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Challener, William

    2014-12-31

    This report describes the work completed on contract DE-FE0010116. The goal of this two year project was to develop and demonstrate in the laboratory a highly accurate multi-point pressure measurement fiber optic cable based on MEMS pressure sensors suitable for downhole deployment in a CO2 sequestration well. The sensor interrogator was also to be demonstrated in a remote monitoring system and environmental testing was to be completed to indicate its downhole survivability over a lengthy period of time (e.g., 20 years). An interrogator system based on a pulsed laser excitation was shown to be capable of multiple (potentially 100+) simultaneous sensor measurements. Two sensors packages were completed and spliced in a cable onto the same fiber and measured. One sensor package was subsequently measured at high temperatures and pressures in supercritical CO2, while the other package was measured prior and after being subjected to high torque stresses to mimic downhole deployment. The environmental and stress tests indicated areas in which the package design should be further improved.

  10. Fiber optic sensing of relative humidity using a twin low coherence interferometer

    Scientific Electronic Library Online (English)

    A.V., Khomenko; J., Tapia-Mercado; M.A., García-Zarate.

    2010-06-01

    Full Text Available En este trabajo se describe un sensor de humedad de fibra óptica que consiste en dos interferómetros de Sagnac con secciones de fibra óptica torcida de alta birrefringencia. Las fibras birrefringentes sirven como elementos sensibles a la temperatura que permiten medir simultáneamente la temperatura [...] de bulbo seco y bulbo mojado. Se describe el método para interrogación de dos sensores de temperatura basados en la interferometría de baja coherencia con procesamiento de señales en el dominio espectral. La incertidumbre de la medición, estimada experimentalmente, es de 0.01°C y 4% para mediciones de temperatura y humedad, respectivamente. Abstract in english A fiber-optic implementation of psychrometer is reported. It consists of two Sagnac interferometers with twisted highly birefringent fiber that is used as a temperature sensitive element. One interferometer is used for dry-bulb temperature measurement and the other is for wet-bulb temperature monito [...] ring. The interrogation technique for low coherence interferometric sensor with signal processing in spectral domain is described. The measurement uncertainties for temperature and relative humidity measurements no worse than 0.01°C and 4%, respectively, have been achieved experimentally.

  11. Nonlinear Fiber Optics

    Science.gov (United States)

    Agrawal, Govind P.

    Nonlinear fiber optics concerns with the nonlinear optical phenomena occurring inside optical fibers. Although the field of nonlinear optics traces its beginning to 1961, when a ruby laser was first used to generate the second-harmonic radiation inside a crystal [1], the use of optical fibers as a nonlinear medium became feasible only after 1970 when fiber losses were reduced to below 20 dB/km [2]. Stimulated Raman and Brillouin scatterings in single-mode fibers were studied as early as 1972 [3] and were soon followed by the study of other nonlinear effects such as self- and cross-phase modulation and four-wave mixing [4]. By 1989, the field of nonlinear fiber optics has advanced enough that a whole book was devoted to it [5]. This book or its second edition has been translated into Chinese, Japanese, and Russian languages, attesting to the worldwide activity in the field of nonlinear fiber optics.

  12. Application of optical fiber distributed sensing to health monitoring of concrete structures

    Science.gov (United States)

    Villalba, Sergi; Casas, Joan R.

    2013-08-01

    The use of Optical Backscatter Reflectometer (OBR) sensors is a promising measurement technology for Structural Health Monitoring (SHM) as it offers the possibility of continuous monitoring of strain and temperature along the fiber. Several applications to materials used in the aeronautical construction have demonstrated the feasibility of such technique. These materials (composites, steel, aluminum) apart from having a smooth surface where the bonding of the sensor is easily carried out, they also have a continuous strain field when subject to external loading and therefore the bonding of the OBR on the material surface is not in danger for high levels of loading as the OBR can easily follow the strain in the material. The application of such type of sensor to concrete structures may present some difficulties due to (1) the roughness of the concrete surface and the heterogeneity due to the presence of aggregates of several sizes, (2) the fact that reinforced concrete cracks at very low level of load, appearance of a discontinuity in the surface and the strain field that may provoke a break or debonding of the optical fiber. However the feasibility of using OBR in the SHM of civil engineering constructions made of concrete is also of great interest, mainly because in this type of structures it is impossible to know where the crack may appear and therefore severe cracking (dangerous for the structure operation) can appear without warning of the monitoring if sensors are not placed in the particular location where the crack appears. In order to explore the potentiality of detecting cracks as they appear without failure or debonding, as well as the compatibility of the OBR bonding to the concrete surfaces, this paper shows the test carried out in the loading up to failure of a concrete slab.

  13. Sapphire ball lensed fiber probe for common-path optical coherence tomography in ocular imaging and sensing

    Science.gov (United States)

    Zhao, Mingtao; Huang, Yong; Kang, Jin U.

    2013-03-01

    We describe a novel common-path optical coherence tomography (CP-OCT) fiber probe design using a sapphire ball lens for cross-sectional imaging and sensing in retina vitrectomy surgery. Single mode Gaussian beam (TEM00) simulation was used to optimize lateral resolution and working distance (WD) of the common-path probe. A theoretical sensitivity model for CP-OCT was prosed to assess its optimal performance based an unbalanced photodetector configuration. Two probe designs with working distances (WD) 415?m and 1221?m and lateral resolution 11?m and 18?m, respectively were implemented with sensitivity up to 88dB. The designs are also fully compatible with conventional Michelson interferometer based OCT configurations. The reference plane of the probe, located at the distal beam exit interface of the single mode fiber (SMF), was encased within a 25-gauge hypodermic needle by the sapphire ball lens facilitates its applications in bloody and harsh environments. The performances of the fiber probe with 11?m of lateral resolution and 19?m of axial resolution were demonstrated by cross-sectional imaging of a cow cornea and retina in vitro with a 1310nm swept source OCT system. This probe was also attached to a piezoelectric motor for active compensation of physiological tremor for handheld retinal surgical tools.

  14. [The recent development of fiber-optic chemical sensor].

    Science.gov (United States)

    Wang, Jian; Wei, Jian-ping; Yang, Bo; Gao, Zhi-yang; Zhang, Li-wei; Yang, Xue-feng

    2014-08-01

    The present article provides a brief review of recent research on fiber-optic chemical sensor technology and the future development trends. Especially, fiber-optic pH chemical sensor, fiber-optic ion chemicl sensor, and fiber-optic gas chemical sensor are introduced respectively. Sensing film preparation methods such as chemical bonding method and sol-gel method were briefly reviewed. The emergence of new type fiber-microstructured optical fiber opened up a new development direction for fiber-optic chemical sensor. Because of its large inner surface area, flexible design of structure, having internal sensing places in fibers, it has rapidly become an important development direction and research focus of the fiber-optic chemical sensors. The fiber-optic chemical sensor derived from microstructured optical fiber is also discussed in detail. Finally, we look to the future of the fiber-optic chemical sensor. PMID:25508709

  15. Fiber optic micro accelerometer

    Science.gov (United States)

    Swierkowski, Steve P.

    2005-07-26

    An accelerometer includes a wafer, a proof mass integrated into the wafer, at least one spring member connected to the proof mass, and an optical fiber. A Fabry-Perot cavity is formed by a partially reflective surface on the proof mass and a partially reflective surface on the end of the optical fiber. The two partially reflective surfaces are used to detect movement of the proof mass through the optical fiber, using an optical detection system.

  16. Statistical mapping of zones of focused groundwater/surface-water exchange using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Mwakanyamale, Kisa; Day-Lewis, Frederick D.; Slater, Lee D.

    2013-01-01

    Fiber-optic distributed temperature sensing (FO-DTS) increasingly is used to map zones of focused groundwater/surface-water exchange (GWSWE). Previous studies of GWSWE using FO-DTS involved identification of zones of focused GWSWE based on arbitrary cutoffs of FO-DTS time-series statistics (e.g., variance, cross-correlation between temperature and stage, or spectral power). New approaches are needed to extract more quantitative information from large, complex FO-DTS data sets while concurrently providing an assessment of uncertainty associated with mapping zones of focused GSWSE. Toward this end, we present a strategy combining discriminant analysis (DA) and spectral analysis (SA). We demonstrate the approach using field experimental data from a reach of the Columbia River adjacent to the Hanford 300 Area site. Results of the combined SA/DA approach are shown to be superior to previous results from qualitative interpretation of FO-DTS spectra alone.

  17. An Efficient Wavelength variation approach for Bend Sensing in Single mode-Multimode-Single mode Optical Fiber Sensors

    Directory of Open Access Journals (Sweden)

    Abdul Samee Khan

    2012-09-01

    Full Text Available Several aspects of the SMS edge filters have been investigated, including the effect of bending the SMS fiber cores due to fabrication tolerances, polarization dependence, and temperature dependence. These aspects can impair the performance of a wavelength measurement system. There are several approaches which have been proposed and demonstrated to achieve high resolution and accuracy of wavelength measurement. Bending effects due to the splicing process on the spectral characteristics of SMS fibre structure-based edge filters are investigated experimentally with the help of MATLAB. A limit for the tolerable of the cores of an SMS fibre structure-based edge filter is proposed, beyond which the edge filter’s spectral performance degrades unacceptably. We use Wavelength variation approach by which we reduce the power loss due to the bending in the optical fiber. Due to the power loss the power transmission is increases and efficiency reduces. So by wavelength variation approach we developed an efficient spectrometer capable of performing a wide variety of coherent multidimensional measurements at optical wavelengths. In this approach we fixed the power and perform variation in the wavelength to sense the bending accurately. The two major components of the largely automated device are a spatial beam shaper which controls the beam geometry and a spatiotemporal pulse shaper which controls the temporal waveform of the femtosecond pulse in each beam. By which we sense the distortion to reduce the power transmission. We apply our algorithm for performing several comparison considerations which shows the performance of our algorithm which is better in comparison to the previous work.

  18. Specialty fiber optic applications for harsh and high radiation environments

    Science.gov (United States)

    Risch, Brian G.

    2015-05-01

    Since the first commercial introduction in the 1980s, optical fiber technology has undergone an almost exponential growth. Currently over 2 billion fiber kilometers are deployed globally with 2014 global optical fiber production exceeding 300 million fiber kilometers. 1 Along with the staggering growth in optical fiber production and deployment, an increase in optical fiber technologies and applications has also followed. Although the main use of optical fibers by far has been for traditional data transmission and communications, numerous new applications are introduced each year. Initially the practical application of optical fibers was limited by cost and sensitivity of the optical fibers to stress, radiation, and other environmental factors. Tremendous advances have taken place in optical fiber design and materials allowing optical fibers to be deployed in increasingly harsh environments with exposure to increased mechanical and environmental stresses while maintaining high reliability. With the increased reliability, lower cost, and greatly expanded range of optical fiber types now available, new optical fiber deployments in harsh and high radiation environments is seeing a tremendous increase for data, communications, and sensing applications. An overview of key optical fiber applications in data, communications, and sensing for harsh environments in industrial, energy exploration, energy generation, energy transmission, and high radiation applications will be presented. Specific recent advances in new radiation resistant optical fiber types, other specialty optical fibers, optical fiber coatings, and optical fiber cable materials will be discussed to illustrate long term reliability for deployment of optical fibers in harsh and high radiation environments.

  19. Rayleigh fiber optics gyroscope

    OpenAIRE

    Kung, A.; Budin, J.; Thévenaz, Luc; Robert, P. A.

    1997-01-01

    A novel kind of fiber-optic gyroscope based on Rayleigh backscattering in a fiber-ring resonator is presented in this letter. Information on the rotation rate is obtained from the composed response of the fiber ring to an optical time-domain reflectometry (OTDR) instrument. The developed model based on the coherence properties of the Rayleigh scattering yields a polarization-insensitive and low-cost gyroscope

  20. Improving Photovoltaic Energy Production with Fiber-Optic Distributed Temperature Sensing

    Science.gov (United States)

    Hausner, M. B.; Berli, M.

    2014-12-01

    The efficiency of solar photovoltaic (PV) generators declines sharply with increased temperatures. Peak solar exposure often occurs at the same time as peak temperatures, but solar PV installations are typically designed based on solar angle. In temperate areas, the peak temperatures may not be high enough to induce significant efficiency losses. In some of the areas with the greatest potential for solar development, however, summer air temperatures regularly reach 45 °C and PV panel temperatures exceed the air temperatures. Here we present a preliminary model of a PV array intended to optimize solar production in a hot and arid environment. The model begins with the diurnal and seasonal cycles in the angle and elevation of the sun, but also includes a meteorology-driven energy balance to project the temperatures of the PV panels and supporting structure. The model will be calibrated and parameterized using a solar array at the Desert Research Institute's (DRI) Renewable Energy Deployment and Display (REDD) facility in Reno, Nevada, and validated with a similar array at DRI's Las Vegas campus. Optical fibers will be installed on the PV panels and structural supports and interrogated by a distributed temperature sensor (DTS) to record the spatial and temporal variations in temperature. Combining the simulated panel temperatures, the efficiency-temperature relationship for the panels, and the known solar cycles at a site will allow us to optimize the design of future PV collectors (i.e., the aspect and angle of panels) for given production goals.

  1. Hydrogen Optical Fiber Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Lieberman, Robert A.; Beshay, Manal; Cordero, Steven R.

    2008-07-28

    Optically-based hydrogen sensors promise to deliver an added level of safety as hydrogen and fuel cell technologies enter the mainstream. More importantly, they offer reduced power consumption and lower cost, which are desirable for mass production applications such as automobiles and consumer appliances. This program addressed two of the major challenges previously identified in porous optrode-based optical hydrogen sensors: sensitivity to moisture (ambient humidity), and interference from the oxygen in air. Polymer coatings to inhibit moisture and oxygen were developed in conjunction with newer and novel hydrogen sensing chemistries. The results showed that it is possible to achieve sensitive hydrogen detection and rapid response with minimal interference from oxygen and humidity. As a result of this work, a new and more exciting avenue of investigation was developed: the elimination of the porous optrode and deposition of the sensor chemistry directly into the polymer film. Initial results have been promising, and open up a wider range of potential applications from extended optical fiber sensing networks, to simple plastic "stickers" for use around the home and office.

  2. Indium-Tin-Oxide coated optical fibers for temperature-viscosity sensing applications in synthetic lubricant oils

    Science.gov (United States)

    Sanchez, P.; Mendizabal, D.; R. Zamarreño, C.; Arregui, F. J.; Matias, I. R.

    2015-09-01

    In this work, is presented the fabrication and characterization of optical fiber refractometer based on lossy mode resonances (LMR). Indium-Tin-Oxide (ITO) thin films deposited on optical fibers are used as the LMR supporting coatings. These resonances shift to the red as a function of the external refractive index. The refractometer has been used to characterize temperature variations related to the viscosity of synthetic industrial gear lubricant.

  3. Woven fiber optics.

    Science.gov (United States)

    Schmidt, A C; Courtney-Pratt, J S; Ross, E A

    1975-02-01

    In this paper we describe how the art of weaving can be applied to fiber optics in order to produce precisely controlled reproducible image guides and image dissectors. As examples of the types of device for which woven fiber optics are applicable, we describe a 3:1 interleaver for use with a cathode-ray tube to produce color images, and a high speed alpha numeric output device. The techniques of weaving fiber optics are discussed in sufficient detail in order to allow for further work. Although, in principle, one might be able to weave glass optical fibers, all the work described here made use of plastic optical fibers 0.25 mm in diameter. PMID:20134880

  4. Fiber optic hydrophone

    Science.gov (United States)

    Kuzmenko, Paul J. (Livermore, CA); Davis, Donald T. (Livermore, CA)

    1994-01-01

    A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer. The hydrophone, in one embodiment, includes a body having a shaped flexible bladder at one end which defines a volume containing air or suitable gas, and including a membrane disposed adjacent a vent. An optic fiber extends into the body with one end terminating in spaced relation to the membrane. Acoustic waves in the water that impinge on the bladder cause the pressure of the volume therein to vary causing the membrane to deflect and modulate the reflectivity of the Fabry-Perot cavity formed by the membrane surface and the cleaved end of the optical fiber disposed adjacent to the membrane. When the light is transmitted down the optical fiber, the reflected signal is amplitude modulated by the incident acoustic wave. Another embodiment utilizes a fluid filled volume within which the fiber optic extends.

  5. Sub-cm Resolution Distributed Fiber Optic Hydrogen Sensing with Nano-Engineered TiO2

    OpenAIRE

    Poole, Zsolt; Ohodnicki, Paul; Yan, Aidong; Lin, Yuankun; Chen, Kevin

    2015-01-01

    The 3D nano-structuring on the 2) to be reduced and matched with the cladding of optical fiber(n~1.46) for low-loss integration. A high temperature capable hydrogen sensor composed of D-shaped optical fiber with palladium nanoparticles infused nanoporous (~5nm) TiO2 film is demonstrated. The behavior of the developed sensor was characterized by examining the wavelength of an incorporated Fiber Bragg Grating and by observing the transmission losses at temperatures up to 700C....

  6. Multi optical path generator for fiber optic strain sensors multiplexing

    Science.gov (United States)

    Luo, Hao; Yuan, Yonggui; Yuan, Libo

    2015-07-01

    A multi optical path generator based on a tunable long Fabry-Perot optical fiber cavity is proposed and demonstrated. It would be used in an optical fiber sensing system which could multiplex a number of fiber sensors with different gauge lengths. Using this optical path generator, we can get a sequence of light beams with different optical paths, which will be coupled to the fiber sensor array in the sensing system. The multi optical path lengths generated by the device are analyzed and discussed. And the relative intensity of the corresponding light beam is calculated. The multiplexing capability caused by the optical path generator is discussed and the experimental results are confirmed this. The system can be used in strain or deformation sensing for smart structure health monitoring.

  7. Soil-embedded optical fiber sensing cable interrogated by Brillouin optical time-domain reflectometry (B-OTDR) and optical frequency-domain reflectometry (OFDR) for embedded cavity detection and sinkhole warning system

    International Nuclear Information System (INIS)

    A soil-embedded optical fiber sensing cable is evaluated for an embedded cavity detection and sinkhole warning system in railway tunnels. Tests were performed on a decametric structure equipped with an embedded 110 m long fiber optic cable. Both Brillouin optical time-domain reflectometry (B-OTDR) and optical frequency-domain reflectometry (OFDR) sensing techniques were used for cable interrogation, yielding results that were in good qualitative agreement with finite-element calculations. Theoretical and experimental comparison enabled physical interpretation of the influence of ground properties, and the analysis of embedded cavity size and position. A 5 mm embedded cavity located 2 m away from the sensing cable was detected. The commercially available sensing cable remained intact after soil collapse. Specificities of each technique are analyzed in view of the application requirements. For tunnel monitoring, the OFDR technique was determined to be more viable than the B-OTDR due to higher spatial resolution, resulting in better detection and size determination of the embedded cavities. Conclusions of this investigation gave outlines for future field use of distributed strain-sensing methods under railways and more precisely enabled designing a warning system suited to the Ebersviller tunnel specificities

  8. High-power fiber laser sources for remote sensing

    Science.gov (United States)

    Di Teodoro, Fabio

    2013-09-01

    Pulse fiber lasers constitute a promising optical transmitter technology for remote sensing applications characterized by tight size, power consumption, and ruggedness constraints. In this paper, we review laser architecture and component solutions that support power scaling of efficient fiber-based sources towards long-range operation consistent with imaging and/or chemical sensing from space-based platforms.

  9. Fiber optic spanner

    Science.gov (United States)

    Black, Bryan; Mohanty, Samarendra

    2011-10-01

    Rotation is a fundamental function in nano/biotechnology and is being useful in a host of applications such as pumping of fluid flow in microfluidic channels for transport of micro/nano samples. Further, controlled rotation of single cell or microscopic object is useful for tomographic imaging. Though conventional microscope objective based laser spanners (based on transfer of spin or orbital angular momentum) have been used in the past, they are limited by the short working distance of the microscope objective. Here, we demonstrate development of a fiber optic spanner for rotation of microscopic objects using single-mode fiber optics. Fiber-optic trapping and simultaneous rotation of pin-wheel structure around axis perpendicular to fiber-optic axis was achieved using the fiber optic spanner. By adjusting the laser beam power, rotation speed of the trapped object and thus the microfluidic flow could be controlled. Since this method does not require special optical or structural properties of the sample to be rotated, three-dimensional rotation of a spherical cell could also be controlled. Further, using the fiber optic spanner, array of red blood cells could be assembled and actuated to generate vortex motion. Fiber optical trapping and spinning will enable physical and spectroscopic analysis of microscopic objects in solution and also find potential applications in lab- on-a-chip devices.

  10. Fiber optics standard dictionary

    CERN Document Server

    Weik, Martin H

    1997-01-01

    Fiber Optics Vocabulary Development In 1979, the National Communications System published Technical InfonnationBulle­ tin TB 79-1, Vocabulary for Fiber Optics and Lightwave Communications, written by this author. Based on a draft prepared by this author, the National Communications System published Federal Standard FED-STD-1037, Glossary of Telecommunications Terms, in 1980 with no fiber optics tenns. In 1981, the first edition of this dictionary was published under the title Fiber Optics and Lightwave Communications Standard Dictionary. In 1982, the then National Bureau of Standards, now the National Institute of Standards and Technology, published NBS Handbook 140, Optical Waveguide Communications Glossary, which was also published by the General Services Admin­ istration as PB82-166257 under the same title. Also in 1982, Dynamic Systems, Inc. , Fiberoptic Sensor Technology Handbook, co-authored and edited by published the this author, with an extensive Fiberoptic Sensors Glossary. In 1989, the handbook w...

  11. A comparison of thermal infrared to fiber-optic distributed temperature sensing for evaluation of groundwater discharge to surface water

    Science.gov (United States)

    Hare, Danielle K.; Briggs, Martin A.; Rosenberry, Donald O.; Boutt, David F.; Lane, John W.

    2015-11-01

    Groundwater has a predictable thermal signature that can be used to locate discrete zones of discharge to surface water. As climate warms, surface water with strong groundwater influence will provide habitat stability and refuge for thermally stressed aquatic species, and is therefore critical to locate and protect. Alternatively, these discrete seepage locations may serve as potential point sources of contaminants from polluted aquifers. This study compares two increasingly common heat tracing methods to locate discrete groundwater discharge: direct-contact measurements made with fiber-optic distributed temperature sensing (FO-DTS) and remote sensing measurements collected with thermal infrared (TIR) cameras. FO-DTS is used to make high spatial resolution (typically m) thermal measurements through time within the water column using temperature-sensitive cables. The spatial-temporal data can be analyzed with statistical measures to reveal zones of groundwater influence, however, the personnel requirements, time to install, and time to georeference the cables can be burdensome, and the control units need constant calibration. In contrast, TIR data collection, either from handheld, airborne, or satellite platforms, can quickly capture point-in-time evaluations of groundwater seepage zones across large scales. However the remote nature of TIR measurements means they can be adversely influenced by a number of environmental and physical factors, and the measurements are limited to the surface "skin" temperature of water features. We present case studies from a range of lentic to lotic aquatic systems to identify capabilities and limitations of both technologies and highlight situations in which one or the other might be a better instrument choice for locating groundwater discharge. FO-DTS performs well in all systems across seasons, but data collection was limited spatially by practical considerations of cable installation. TIR is found to consistently locate groundwater seepage zones above and along the streambank, but submerged seepage zones are only well identified in shallow systems (e.g. warm and buoyant, increases the water surface expression of discharge zones in shallow systems.

  12. Optical fiber spectrophotometer

    International Nuclear Information System (INIS)

    A method called 'Two Arm's Photo out and Electricity Send-back' is introduced. UV-365 UV/VIS/NIR spectrophotometer has been reequipped by this way with 5 meters long optical fiber. Another method called 'One Arm's Photo out and Photo Send-back' is also introduced. ?19 UV/VIS/NIR spectrophotometer has been reequipped by this way with 10 meters long optical fiber. Optical fiber spectrophotometer can work as its main set. So it is particularly applicable to radio activity work

  13. Remote optical sensing on the nanometer scale with a bowtie aperture nano-antenna on a SNOM fiber tip

    OpenAIRE

    Atie, Elie M.; Xie, Zhihua; Eter, Ali El; Salut, Roland; Nedeljkovic, Dusan; Tannous, Tony; Baida, Fadi I.; Grosjean, Thierry

    2015-01-01

    Plasmonic nano-antennas have proven the outstanding ability of sensing chemical and physical processes down to the nano-meter scale. Sensing is usually achieved within the highly confined optical fields generated resonantly by the nano-antennas, i.e. in contact to the nano-structures. In these paper, We demonstrate the sensing capability of nano-antennas to their larger scale environment, well beyond their plasmonic confinement volume, leading to the concept of 'remote' (non...

  14. Chemical sensing with optical fibers and planar waveguides for biomedical applications

    Science.gov (United States)

    Verga Scheggi, Anna M.; Baldini, Francesco

    1994-02-01

    Main physical phenomena, exploited for the realization of optical chemical sensors, and different immobilization techniques for the realization of the optrode are reviewed and general considerations on the optoelectronic system are given. Many interesting examples of constructed optrodes are described.

  15. Fiber optic sensing of magnetic fields utilizing femtosecond laser sculpted microslots and long period gratings coated with Terfenol-D

    Science.gov (United States)

    Lee, Graham C. B.; Allsop, Tom; Wang, Changle; Neal, Ron; Culverhouse, Philip; Webb, David J.

    2015-09-01

    Fiber optic sensors are fabricated for detecting static magnetic fields. The sensors consist of a UV inscribed long period grating with two 50 micron long microslots. The microslots are fabricated using the femtosecond laser based inscribe and etch technique. The microslots and the fiber surface are coated with a magnetostrictive material Terfenol-D. A spectral sensitivity of 1.15 pm/mT was measured in transmission with a working resolution of ±0.2 mT for a static magnetic field strength below 10 mT. These devices also present a different response when the spatial orientation of the fiber was adjusted relative to the magnetic field lines.

  16. Fiber optic data transmission

    Science.gov (United States)

    Shreve, Steven T.

    1987-01-01

    The Ohio University Avionics Engineering Center is currently developing a fiber optic data bus transmission and reception system that could eventually replace copper cable connections in airplanes. The original form of the system will transmit information from an encoder to a transponder via a fiber optic cable. An altimeter and an altitude display are connected to a fiber optic transmitter by copper cable. The transmitter converts the altimetry data from nine bit parallel to serial form and send these data through a fiber optic cable to a receiver. The receiver converts the data using a cable similar to that used between the altimeter and display. The transmitting and receiving ends also include a display readout. After completion and ground testing of the data bus, the system will be tested in an airborne environment.

  17. Novel silica surface charge density mediated control of the optical properties of embedded optically active materials and its application for fiber optic pH sensing at elevated temperatures

    Science.gov (United States)

    Wang, Congjun; Ohodnicki, Paul R.; Su, Xin; Keller, Murphy; Brown, Thomas D.; Baltrus, John P.

    2015-01-01

    Silica and silica incorporated nanocomposite materials have been extensively studied for a wide range of applications. Here we demonstrate an intriguing optical effect of silica that, depending on the solution pH, amplifies or attenuates the optical absorption of a variety of embedded optically active materials with very distinct properties, such as plasmonic Au nanoparticles, non-plasmonic Pt nanoparticles, and the organic dye rhodamine B (not a pH indicator), coated on an optical fiber. Interestingly, the observed optical response to varying pH appears to follow the surface charge density of the silica matrix for all the three different optically active materials. To the best of our knowledge, this optical effect has not been previously reported and it appears universal in that it is likely that any optically active material can be incorporated into the silica matrix to respond to solution pH or surface charge density variations. A direct application of this effect is for optical pH sensing which has very attractive features that can enable minimally invasive, remote, real time and continuous distributed pH monitoring. Particularly, as demonstrated here, using highly stable metal nanoparticles embedded in an inorganic silica matrix can significantly improve the capability of pH sensing in extremely harsh environments which is of increasing importance for applications in unconventional oil and gas resource recovery, carbon sequestration, water quality monitoring, etc. Our approach opens a pathway towards possible future development of robust optical pH sensors for the most demanding environmental conditions. The newly discovered optical effect of silica also offers the potential for control of the optical properties of optically active materials for a range of other potential applications such as electrochromic devices.Silica and silica incorporated nanocomposite materials have been extensively studied for a wide range of applications. Here we demonstrate an intriguing optical effect of silica that, depending on the solution pH, amplifies or attenuates the optical absorption of a variety of embedded optically active materials with very distinct properties, such as plasmonic Au nanoparticles, non-plasmonic Pt nanoparticles, and the organic dye rhodamine B (not a pH indicator), coated on an optical fiber. Interestingly, the observed optical response to varying pH appears to follow the surface charge density of the silica matrix for all the three different optically active materials. To the best of our knowledge, this optical effect has not been previously reported and it appears universal in that it is likely that any optically active material can be incorporated into the silica matrix to respond to solution pH or surface charge density variations. A direct application of this effect is for optical pH sensing which has very attractive features that can enable minimally invasive, remote, real time and continuous distributed pH monitoring. Particularly, as demonstrated here, using highly stable metal nanoparticles embedded in an inorganic silica matrix can significantly improve the capability of pH sensing in extremely harsh environments which is of increasing importance for applications in unconventional oil and gas resource recovery, carbon sequestration, water quality monitoring, etc. Our approach opens a pathway towards possible future development of robust optical pH sensors for the most demanding environmental conditions. The newly discovered optical effect of silica also offers the potential for control of the optical properties of optically active materials for a range of other potential applications such as electrochromic devices. Electronic supplementary information (ESI) available: Schematic of the experimental setup, SEM images of the optical fiber sensors, XPS spectra of the sensor materials, as well as additional sensing results from control experiments. See DOI: 10.1039/c4nr06232a

  18. Fiber optic hydrogen sensor

    Science.gov (United States)

    Buchanan, Bruce R. (1985 Willis, Batesburg, SC 29006); Prather, William S. (2419 Dickey Rd., Augusta, GA 30906)

    1992-01-01

    An apparatus and method for detecting a chemical substance by exposing an optic fiber having a core and a cladding to the chemical substance so that the chemical substance can be adsorbed onto the surface of the cladding. The optic fiber is coiled inside a container having a pair of valves for controlling the entrance and exit of the substance. Light from a light source is received by one end of the optic fiber, preferably external to the container, and carried by the core of the fiber. Adsorbed substance changes the transmissivity of the fiber as measured by a spectrophotometer at the other end, also preferably external to the container. Hydrogen is detected by the absorption of infrared light carried by an optic fiber with a silica cladding. Since the adsorption is reversible, a sensor according to the present invention can be used repeatedly. Multiple positions in a process system can be monitored using a single container that can be connected to each location to be monitored so that a sample can be obtained for measurement, or, alternatively, containers can be placed near each position and the optic fibers carrying the partially-absorbed light can be multiplexed for rapid sequential reading by a single spectrophotometer.

  19. Development of special optical fibers for evanescent-wave chemical sensing.

    Czech Academy of Sciences Publication Activity Database

    Mat?jec, Vlastimil; Chomát, Miroslav; Hayer, Miloš; Kašík, Ivan; Berková, Daniela; Abdelmalek, F.; Jaffrezic-Renault, N.

    1999-01-01

    Ro?. 49, ?. 5 (1999), s. 883-888. ISSN 0011-4626. [Czech-Chinese Workshop on Advanced Materials for Optoelectronics - AMFO'98. Prague, 15.06.1998-17.06.1998] R&D Projects: GA ?R GA102/98/1358; GA ?R GA102/96/0939 Institutional research plan: CEZ:AV0Z2067918; Joint project No.4104 AS CR and CNRS France Keywords : optical sensors * optical fibres Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.328, year: 1999

  20. Optical fiber Sagnac interferometer for sensing scalar directional refraction: application to magnetochiral birefringence

    CERN Document Server

    Loas, Goulc'hen; Vallet, Marc

    2014-01-01

    We present a set-up dedicated to the measurement of the small scalar directional anisotropies associated to the magnetochiral interaction. The apparatus, based on a polarization-independent fiber Sagnac interferometer, is optimized to be insensitive to circular anisotropies and to residual absorption. It can thus characterize samples of biological interests, for which the two enantiomers are not available and/or which present poor transmission. The signal-to-noise ratio is shown to be limited only by the source intensity noise, leading to a detection limit of Df = 500 nrad.Hz-1/2. It yields a limit on the magnetochiral index nMC < 4 10-13 T-1 at 1550 nm for the organic molecules tested.

  1. Comparison of evanscent-wave and leaky-wave fiber optic sensing structures for gas detection.

    Czech Academy of Sciences Publication Activity Database

    Mrázek, Jan; Mat?jec, Vlastimil; Chomát, Miroslav; Renault, N. J.; Dzyadevych, S.; Rose, K.

    [Monastir] : [Faculté des Sciences de Monastir], 2004. s. 121. [Journees Maghreb-Europe sur les Materiaux et Leurs Applications aux Dispositifs et Capteurs MADICA 2004 /4./. 29.11.2004-01.12.2004, Tunis ] Institutional research plan: CEZ:AV0Z2067918 Keywords : fibre optic sensors * gas sensors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  2. Nonlinear effects in optical fibers

    CERN Document Server

    Ferreira, Mario F

    2011-01-01

    Cutting-edge coverage of nonlinear phenomena occurring inside optical fibers Nonlinear fiber optics is a specialized part of fiber optics dealing with optical nonlinearities and their applications. As fiber-optic communication systems have become more advanced and complex, the nonlinear effects in optical fibers have increased in importance, as they adversely affect system performance. Paradoxically, the same nonlinear phenomena also offer the promise of addressing the bandwidth bottleneck for signal processing for future ultra-high speed optical networks. Nonlinear Effects in Optical Fiber

  3. Precision Fiber Optic Sensor Market Forecast

    Science.gov (United States)

    Montgomery, Jeff D.; Glasco, Jon; Dixon, Frank W.

    1986-01-01

    The worldwide market for precision fiber optic sensors is forecasted, 1984-1994. The forecast is based upon o Analysis of fiber optic sensor and related component current technology, and a forecast of technology advancement o Review and projection of demand for precision sensing, and the penetration which fiber optics will make into this market The analysis and projections are based mainly on interviews conducted worldwide with research teams, government agencies, systems contractors, medical and industrial laboratories, component suppliers and others. The worldwide market for precision (interferometric) fiber optic sensing systems is forecasted to exceed $0.8 billion by 1994. The forecast is segmented by geographical region (Europe, Japan and North America) and by function; o Gyroscope o Sonar o Gradiometer/Magnetometer o Other - Chemical Composition - Atmospheric Acoustic - Temperature - Position - Pressure Requirements for components are reviewed. These include special fiber, emitters and detectors, modulators, couplers, switches, integrated optical circuits and integrated optoelectronics. The advancement in component performance is forecasted. The major driving forces creating fiber optic sensor markets are reviewed. These include fiber optic sensor technical and economic advantages, increasingly stringent operational requirements, and technology evolution. The leading fiber optic sensor and related component development programs are reviewed. Component sources are listed. Funding sources for sensor and component development are outlined, and trends forecasted.

  4. Assessment of a fiber-optic distributed-temperature-sensing system to monitor the thermal dynamics of vegetated roof

    Science.gov (United States)

    Cousiño, J. A.; Hausner, M. B.; Victorero, F.; Bonilla, C.; Gironas, J. A.; Vera, S.; Bustamante, W.; Rojas, V.; Pasten, P.; Suarez, F. I.

    2014-12-01

    Vegetated (green) roofs include a growing media and vegetation layer, and offer a range of benefits such as the reduction of: the heat island effect, rooftop runoff peak flows, roof surface temperatures, energy used for cooling or heating buildings, and noise levels inside infrastructures. Vegetated roofs also offer aesthetic benefits and increase the biodiversity of the urban environment, and are increasingly used in sustainable urban development. Understanding the thermal dynamics of vegetated roofs will make it possible to improve their design and to better assess their impacts on energy efficiency. Here, we evaluate the first vertical high-resolution distributed-temperature-sensing (DTS) system installed in a vegetated roof. This system allows a continuous measurement of the thermal profile within a vegetated roof - going from the interior, upward through the drainage layers and soil substrate of the vegetated roof and ending in the air above the vegetation. Temperatures can be observed as frequently as every 30 s at a spatial resolution on the order of centimeters. This DTS system was installed in the "Laboratory of Vegetal Infrastructure of Buildings" (LIVE - its acronym in Spanish), located in the San Joaquín Campus of the Pontifical Catholic University, Santiago, Chile. The laboratory features 18 experimental modules to investigate different configurations of the vegetated roof layers. The LIVE was designed with the installation of the optical fibers in mind, and the DTS system allows simultaneous monitoring of three or four modules of the LIVE. In this work, we describe the design of this DTS deployment, the calibration metrics obtained using the software provided by the manufacturers, and other calibration algorithms previously developed. We compare the results obtained using single- and double-ended measurements, highlighting strengths and weaknesses of DTS methods. Finally, we present the observations obtained from this biophysical environment highlighting the features that are harder to observe using more traditional methods to measure temperature.

  5. Vapor sensing properties of carbon nanotubes onto cadmium arachidate multilayer investigated by optical-fiber-based reflectometer sensor and acoustic sensors

    Science.gov (United States)

    Cusano, A.; Cutolo, Antonello; Penza, M.; Cassano, G.; Aversa, P.; Antolini, F.; Giordano, Michele

    2004-06-01

    We have investigated the sensing properties of the carbon nanotubes deposited onto a cadmium arachidate buffered multilayer by acoustic sensors -- SAW and QCM -- and a reflectometric sensor system based on optical fiber for purposes of chemical detection of volatile organic compound (VOCs), at room temperature. The carbon nanotubes have been deposited by the molecular engineering Langmuir-Blodgett (L-B) technique onto a buffer multilayer of cadmium arachidate prepared monolayer-by-monolayer using the L-B technique as well. The sensing multilayered material has been prepared both onto a standard silica optical fiber configured in a reflectometer sensor system and onto acoustic sensors -- SAW and QCM -- configured as oscillators. The acoustic sensors and the optical sensor have been exposed simultaneously, in the same test chamber, towards different VOCs such as ethanol, methanol, iso-propanol, acetone, ethylacetate, toluene with different vapor pressures for comparing the sensitivity of the coating onto the different kinds of acoustic and optical transducers. Moreover, for the same type of transducer, acoustic or optical, the effect of carbon nanotubes onto the gas sensitivity is remarkably higher in all investigated cases.

  6. Silicon fiber optic sensors

    Science.gov (United States)

    Pocha, Michael D. (Livermore, CA); Swierkowski, Steve P. (Livermore, CA); Wood, Billy E. (Livermore, CA)

    2007-10-02

    A Fabry-Perot cavity is formed by a partially or wholly reflective surface on the free end of an integrated elongate channel or an integrated bounding wall of a chip of a wafer and a partially reflective surface on the end of the optical fiber. Such a constructed device can be utilized to detect one or more physical parameters, such as, for example, strain, through the optical fiber using an optical detection system to provide measuring accuracies of less than aboutb0.1%.

  7. Optical Waveguide Sensing and Imaging

    CERN Document Server

    Bock, Wojtek J; Tanev, Stoyan

    2008-01-01

    The book explores various aspects of existing and emerging fiber and waveguide optics sensing and imaging technologies including recent advances in nanobiophotonics. The focus is both on fundamental and applied research as well as on applications in civil engineering, biomedical sciences, environment, security and defence. The main goal of the multi-disciplinarry team of Editors was to provide an useful reference of state-of-the-art overviews covering a variety of complementary topics on the interface of engineering and biomedical sciences.

  8. FIBER OPTIC LIGHTING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Munir BATUR

    2013-01-01

    Full Text Available Recently there have been many important and valuable developments in the communication industry. The huge increase in the sound, data and visual communications has caused a parallel increase in the demand for systems with wider capacity, higher speed and higher quality. Communication systems that use light to transfer data are immensely increased. There have recently many systems in which glass or plastic fiber cables were developed for light wave to be transmitted from a source to a target place. Fiber optic systems, are nowadays widely used in energy transmission control systems, medicine, industry and lighting. The basics of the system is, movement of light from one point to another point in fiber cable with reflections. Fiber optic lighting systems are quite secure than other lighting systems and have flexibility for realizing many different designs. This situation makes fiber optics an alternative for other lighting systems. Fiber optic lighting systems usage is increasing day-by-day in our life. In this article, these systems are discussed in detail.

  9. Optical remote sensing

    CERN Document Server

    Prasad, Saurabh; Chanussot, Jocelyn

    2011-01-01

    Optical remote sensing relies on exploiting multispectral and hyper spectral imagery possessing high spatial and spectral resolutions respectively. These modalities, although useful for most remote sensing tasks, often present challenges that must be addressed for their effective exploitation. This book presents current state-of-the-art algorithms that address the following key challenges encountered in representation and analysis of such optical remotely sensed data: challenges in pre-processing images, storing and representing high dimensional data, fusing different sensor modalities, patter

  10. Fiber optic accelerometer

    Science.gov (United States)

    August, R. R.

    1981-01-01

    Low-cost, rugged lightweight accelerometer has been developed that converts mechanical motion into digitized optical outputs and is immune to electromagnetic and electrostatic interferences. Instrument can be placed in hostile environment, such as engine under test, and output led out through miscellany of electrical fields, high temperatures, etc., by optic fiber cables to benign environment of test panel. There, digitized optical signals can be converted to electrical signals for use in standard electrical equipment or used directly in optical devices, such as optical digital computer.

  11. Fiber-optical microphones and accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole; Jacobsen, Torben K.; Rose, Bjarke; Herholdt-Rasmussen, Nicolai; Nielsen, Finn Kryger; Andresen, Søren; Sørensen, Ole Brøsted; Hansen, Knud Styhr

    2010-01-01

    Polymer optical fibers (POFs) are ideal for applications as the sensing element in fiber-optical microphones and accelerometers based on fiber Bragg gratings (FBGs) due to their reduced Young’s Modulus of 3.2GPa, compared to 72GPa of Silica. To maximize the sensitivity and the dynamic range of the device the outer diameter and the length of the sensing fiber segment should be as small as possible. To this end we have fabricated 3mm FBGs in single-mode step-index POFs of diameter 115 micron, usin...

  12. Fiber optic gas sensor

    Science.gov (United States)

    Chen, Peng (Inventor); Buric, Michael P. (Inventor); Swinehart, Philip R. (Inventor); Maklad, Mokhtar S. (Inventor)

    2010-01-01

    A gas sensor includes an in-fiber resonant wavelength device provided in a fiber core at a first location. The fiber propagates a sensing light and a power light. A layer of a material is attached to the fiber at the first location. The material is able to absorb the gas at a temperature dependent gas absorption rate. The power light is used to heat the material and increases the gas absorption rate, thereby increasing sensor performance, especially at low temperatures. Further, a method is described of flash heating the gas sensor to absorb more of the gas, allowing the sensor to cool, thereby locking in the gas content of the sensor material, and taking the difference between the starting and ending resonant wavelengths as an indication of the concentration of the gas in the ambient atmosphere.

  13. Optical detection of toluene in water by using an IGI optical fiber with a short sensing region.

    Czech Academy of Sciences Publication Activity Database

    Chomát, Miroslav; Berková, Daniela; Mat?jec, Vlastimil; Kašík, Ivan; Kuncová, Gabriela; Hayer, Miloš

    B87, ?. 2 (2002), s. 258-267. ISSN 0925-4005 R&D Projects: GA ?R GA102/99/0548 Institutional research plan: CEZ:AV0Z2067918 Keywords : optical fibres * fibre optic sensors * chemical sensors Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.893, year: 2002

  14. Dosimetry by optical fibers

    International Nuclear Information System (INIS)

    The Cea-Leti continues to perfect a prototype system to measure the radioactivity by optical fiber captor, developed in the frame of a collaboration with Cogema, whom one of the objectives is the operational dosimetry of extremities. This experimental device, developed by the Dein, uses a micro detector (diameter 200 ? m) with luminescence optically stimulated (O.S.L.) placed at the extremity of an off-centring optical fiber (40 m for the actual prototype). The detector material is a doped alkaline-earth sulfate, developed by the University of Montpellier. It shows the property to restore the image of absorbed dose under the shape of a visible luminescence when it is submitted to a stimulation in infrared radiation. In the prototype, this stimulation is given by a laser diode coupled to the fiber. Different detector materials have been tested, two have been kept for the prototype development: MgS and CaS. (N.C.)

  15. Fluoride glass fiber optics

    CERN Document Server

    Aggarwal, Ishwar D

    1991-01-01

    Fluoride Glass Fiber Optics reviews the fundamental aspects of fluoride glasses. This book is divided into nine chapters. Chapter 1 discusses the wide range of fluoride glasses with an emphasis on fluorozirconate-based compositions. The structure of simple fluoride systems, such as BaF2 binary glass is elaborated in Chapter 2. The third chapter covers the intrinsic transparency of fluoride glasses from the UV to the IR, with particular emphasis on the multiphonon edge and electronic edge. The next three chapters are devoted to ultra-low loss optical fibers, reviewing methods for purifying and

  16. Optical fiber telecommunications IIIb

    CERN Document Server

    Koch, Thomas L

    2012-01-01

    Updated to include the latest information on light wave technology, Optical Fiber Telecommunication III, Volumes A & B are invaluable for scientists, students, and engineers in the modern telecommunications industry. This two-volume set includes the most current research available in optical fiber telecommunications, light wave technology, and photonics/optoelectronics. The authors cover important background concepts such as SONET, coding device technology, andWOM components as well as projecting the trends in telecommunications for the 21st century.Key Features* One of the hottest subjects of

  17. Theoretical understanding of an alternating dielectric multilayer-based fiber optic SPR sensor and its application to gas sensing

    International Nuclear Information System (INIS)

    In the present work, a detailed theoretical analysis of a surface plasmon resonance (SPR)-based fiber optic sensor with an alternating dielectric multilayer system is carried out. The dielectric system consists of silica and titanium oxide layers. The effect of critical design parameters on the sensor's sensitivity and detection accuracy is studied. The results are explained in terms of appropriate physical phenomena, wherever required. Based on the analysis, a new design of a fiber optic SPR sensor for gas detection is proposed. The analysis of such a gas sensor is carried out for four metals separately for a clear understanding. The proposed gas sensor is able to provide reasonably high values of all the performance parameters simultaneously, as required for an efficient detection of gaseous media

  18. Assessment of fiber optic pressure sensors

    International Nuclear Information System (INIS)

    This report presents the results of a six-month Phase 1 study to establish the state-of-the-art in fiber optic pressure sensing and describes the design and principle of operation of various fiber optic pressure sensors. This study involved a literature review, contact with experts in the field, an industrial survey, a site visit to a fiber optic sensor manufacturer, and laboratory testing of a fiber optic pressure sensor. The laboratory work involved both static and dynamic performance tests. In addition, current requirements for environmental and seismic qualification of sensors for nuclear power plants were reviewed to determine the extent of the qualification tests that fiber optic pressure sensors may have to meet before they can be used in nuclear power plants. This project has concluded that fiber optic pressure sensors are still in the research and development stage and only a few manufacturers exist in the US and abroad which supply suitable fiber optic pressure sensors for industrial applications. Presently, fiber optic pressure sensors are mostly used in special applications for which conventional sensors are not able to meet the requirements

  19. Assessment of fiber optic pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Hashemian, H.M.; Black, C.L.; Farmer, J.P. [Analysis and Measurement Services Corp., Knoxville, TN (United States)

    1995-04-01

    This report presents the results of a six-month Phase 1 study to establish the state-of-the-art in fiber optic pressure sensing and describes the design and principle of operation of various fiber optic pressure sensors. This study involved a literature review, contact with experts in the field, an industrial survey, a site visit to a fiber optic sensor manufacturer, and laboratory testing of a fiber optic pressure sensor. The laboratory work involved both static and dynamic performance tests. In addition, current requirements for environmental and seismic qualification of sensors for nuclear power plants were reviewed to determine the extent of the qualification tests that fiber optic pressure sensors may have to meet before they can be used in nuclear power plants. This project has concluded that fiber optic pressure sensors are still in the research and development stage and only a few manufacturers exist in the US and abroad which supply suitable fiber optic pressure sensors for industrial applications. Presently, fiber optic pressure sensors are mostly used in special applications for which conventional sensors are not able to meet the requirements.

  20. Reduced Gravity Zblan Optical Fiber

    Science.gov (United States)

    Tucker, Dennis S.; Workman, Gary L.; Smith, Guy A.

    2000-01-01

    Two optical fiber pullers have been designed for pulling ZBLAN optical fiber in reduced gravity. One fiber puller was designed, built and flown on board NASA's KC135 reduced gravity aircraft. A second fiber puller has been designed for use on board the International Space Station.

  1. Optical fiber communications

    CERN Document Server

    Keiser, Gerd

    2008-01-01

    The fourth edition of this popular text and reference book presents the fundamental principles for understanding and applying optical fiber technology to sophisticated modern telecommunication systems. Optical-fiber-based telecommunication networks have become a major information-transmission-system, with high capacity links encircling the globe in both terrestrial and undersea installations. Numerous passive and active optical devices within these links perform complex transmission and networking functions in the optical domain, such as signal amplification, restoration, routing, and switching. Along with the need to understand the functions of these devices comes the necessity to measure both component and network performance, and to model and stimulate the complex behavior of reliable high-capacity networks.

  2. Respiratory function monitoring using a real-time three-dimensional fiber-optic shaping sensing scheme based upon fiber Bragg gratings.

    Science.gov (United States)

    Allsop, Thomas; Bhamber, Ranjeet; Lloyd, Glynn; Miller, Martin R; Dixon, Andrew; Webb, David; Ania Castañón, Juan Diego; Bennion, Ian

    2012-11-01

    An array of in-line curvature sensors on a garment is used to monitor the thoracic and abdominal movements of a human during respiration. The results are used to obtain volumetric changes of the human torso in agreement with a spirometer used simultaneously at the mouth. The array of 40 in-line fiber Bragg gratings is used to produce 20 curvature sensors at different locations, each sensor consisting of two fiber Bragg gratings. The 20 curvature sensors and adjoining fiber are encapsulated into a low-temperature-cured synthetic silicone. The sensors are wavelength interrogated by a commercially available system from Moog Insensys, and the wavelength changes are calibrated to recover curvature. A three-dimensional algorithm is used to generate shape changes during respiration that allow the measurement of absolute volume changes at various sections of the torso. It is shown that the sensing scheme yields a volumetric error of 6%. Comparing the volume data obtained from the spirometer with the volume estimated with the synchronous data from the shape-sensing array yielded a correlation value 0.86 with a Pearson's correlation coefficient p<0.01. PMID:23117812

  3. Aerogel-clad optical fiber

    Science.gov (United States)

    Sprehn, Gregory A. (Livermore, CA); Hrubesh, Lawrence W. (Pleasanton, CA); Poco, John F. (Livermore, CA); Sandler, Pamela H. (San Marino, CA)

    1997-01-01

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency.

  4. Quasi-distributed long-gauge fiber optic sensor system

    OpenAIRE

    Linec, Matjaž; Ðonlagi?, Denis

    2012-01-01

    This paper presents a quasi-distributed, long-gauge, sensor system for measurement optical path length variation. This system can be directly applied to long gauge strain and/or temperature sensing. The proposed sensor system is comprised of sensing fiber, which is divided into the sensor?s segments separated by semi reflective mirrors made out of standard optical connectors. Short duration radio-frequency modulated optical bursts are launched into the sensing fiber and phase differences amon...

  5. Fluoride Fibers For Remote Chemical Sensing

    Science.gov (United States)

    Saggese, Steven J.; Shahriari, Mahmoud R.; Sigel, George H.

    1988-07-01

    Fluoride glass optical waveguides (ZBLAN) were coupled to a Fourier Transform Infrared Analyzer (FTIR) to execute remote IR chemical sensing. These fibers were used passively for only signal transmission, and the sensing was accomplished by direct or evanescent absorption of the fundamental modes corresponding to the desired chemical species. Due to the poor chemical and physical durability of fluoride glass, a crystal optrode (ZnSe) was used for evanescent wave absorption to isolate the fibers from the sensing environment. Several different types of chemical mixtures were studied to show the flexibility and limitations of such a system: 1) methane gas concentration in nitrogen using the C-H absorption at 3.31 um, 2) alcohol concentration in water using the C-H absorption at 3.36 um, and 3) water concentration in 1,4 dioxane using the 0-H fundamental stretching mode at 2.9 um. The last mixture proved to be the most difficult to analyze due to the low transmission of the fluoride fiber system in the 2.9 um region.

  6. Sensing with speed of light and simple structure: intensity modulated fiber optic sensors and their industrial applications

    Science.gov (United States)

    Zhao, Yong; Li, Pengsheng; Pu, Zhaobang

    2001-05-01

    Modulated principles of various intensity-based sensors and their industrial applications are presented in this paper. We also presented a novel fiber optic sensor with a special construction like a spoke and the sensor was composed of a single mode emitting fiber as well as eight multimode receiving fibers. This special construction can compensate the light fluctuation and reflectivity variation of the measured surface. What's more, with the novel arrangement of the receiving fibers, it can also improve the slope impact in case of the sensor is used to measure the value of spatial height of a surface. Thus, it can be used to measure a complex surface contour with a fairly good resolution and sensitivity. The preliminary experiments were made to verify the practicability and reliability. The estimated local and vertical resolutions can reach 8 micrometers and 0.1 micrometers , respectively. This sensor system was applied to measure a MJ thread and small shoulder height. The conclusion is made that the developed sensor is suitable for complex surface shape measurement with higher speed, higher accuracy, and can be very good used in industrial application.

  7. A miniature fiber-optic sensor for high-resolution and high-speed temperature sensing in ocean environment

    Science.gov (United States)

    Liu, Guigen; Han, Ming; Hou, Weilin; Matt, Silvia; Goode, Wesley

    2015-05-01

    Temperature measurement is one of the key quantifies in ocean research. Temperature variations on small and large scales are key to air-sea interactions and climate change, and also regulate circulation patterns, and heat exchange. The influence from rapid temperature changes within microstructures are can have strong impacts to optical and acoustical sensor performance. In this paper, we present an optical fiber sensor for the high-resolution and high-speed temperature profiling. The developed sensor consists of a thin piece of silicon wafer which forms a Fabry-Pérot interferometer (FPI) on the end of fiber. Due to the unique properties of silicon, such as large thermal diffusivity, notable thermo-optic effects and thermal expansion coefficients of silicon, the proposed sensor exhibits excellent sensitivity and fast response to temperature variation. The small mass of the tiny probe also contributes to a fast response due to the large surface-tovolume ratio. The high reflective index at infrared wavelength range and surface flatness of silicon endow the FPI a spectrum with high visibilities, leading to a superior temperature resolution along with a new data processing method developed by us. Experimental results indicate that the fiber-optic temperature sensor can achieve a temperature resolution better than 0.001°C with a sampling frequency as high as 2 kHz. In addition, the miniature footprint of the senor provide high spatial resolutions. Using this high performance thermometer, excellent characterization of the realtime temperature profile within the flow of water turbulence has been realized.

  8. In-Line Fiber Optic Interferometric Sensors in Single-Mode Fibers

    OpenAIRE

    De-Wen Duan; Min Liu; Di Wu; Tao Zhu

    2012-01-01

    In-line fiber optic interferometers have attracted intensive attention for their potential sensing applications in refractive index, temperature, pressure and strain measurement, etc. Typical in-line fiber-optic interferometers are of two types: Fabry-Perot interferometers and core-cladding-mode interferometers. It’s known that the in-line fiber optic interferometers based on single-mode fibers can exhibit compact structures, easy fabrication and low cost. In this paper, ...

  9. Fiber optics: A brief introduction

    International Nuclear Information System (INIS)

    A basic introduction into the principles of fiber optics is presented. A review of both the underlying physical principles and the individual elements of typical fiber-optic systems are presented. The optical phenomenon of total internal reflection is reviewed. The basic construction of the optical fiber is presented. Both step-index and graded-index fiber designs are reviewed. Multimode and single-mode fiber constructions are considered and typical performance parameters given. Typical optical-fiber bandwidth and loss characteristics are compared to various common coaxial cables, waveguides, and air transmission. The constructions of optical-fiber cables are reviewed. Both loose-tube and tightly-buffered designs are considered. Several optical connection approaches are presented. Photographs of several representative optical connectors are included. Light Emitting Diode and Laser Diode emitters for fiber-optic applications are reviewed, and some advantages and shortcomings of each are considered. The phenomenon of modal noise is briefly explained. Both PIN and Avalanche photodetectors are reviewed and their performance parameters compared. Methods of data transmission over optical fiber are introduced. Principles of Wavelength, Frequency, and Time Division Multiplexing are briefly presented. The technology of fiber-optic sensors is briefly reviewed with basic principles introduced. The performance of a fiber-optic strain sensor is included as a practical example. 7 refs., 10 figs

  10. Fiber optic hydrogen sensors: a review

    Science.gov (United States)

    Yang, Minghong; Dai, Jixiang

    2014-12-01

    Hydrogen is one of the next generation energies in the future, which shows promising applications in aerospace and chemical industries. Hydrogen leakage monitoring is very dangerous and important because of its low ignition energy, high combustion efficiency, and smallest molecule. This paper reviews the state-of-art development of the fiber optic hydrogen sensing technology. The main developing trends of fiber optic hydrogen sensors are based on two kinds of hydrogen sensitive materials, i.e. palladium-alloy thin films and Pt-doped WO3 coatings. In this review work, the advantages and disadvantages of these two kinds of sensing technologies will be evaluated.

  11. Introduction to optical fiber sensors

    International Nuclear Information System (INIS)

    Optical fiber sensors have many advantages over other types of sensors, for example: Low weight, immunity from EMI, electrical isolation, chemical passivity, and high sensitivity. In this seminar, a brief explanation of the optical fiber sensors, their use, and their advantages will be given. After, a description of the main optical fiber sensor components will be presented. Principles of some kinds of optical fiber sensors will be presented, and the principle of the fiber-optic rotation sensor and its realization will be discussed in some details, as well as its main applications. (author). 5 refs, 8 figs, 2 tabs

  12. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind

    2012-01-01

    Since the 4e appeared, a fast evolution of the field has occurred. The 5e of this classic work provides an up-to-date account of the nonlinear phenomena occurring inside optical fibers, the basis of all our telecommunications infastructure as well as being used in the medical field. Reflecting the big developments in research, this new edition includes major new content: slow light effects, which offers a reduction in noise and power consumption and more ordered network traffic-stimulated Brillouin scattering; vectorial treatment of highly nonlinear fibers; and a brand new chapter o

  13. Advances on Optical Fiber Sensors

    OpenAIRE

    Luciano Mescia; Francesco Prudenzano

    2013-01-01

    In this review paper some recent advances on optical fiber sensors are reported. In particular, fiber Bragg grating (FBG), long period gratings (LPGs), evanescent field and hollow core optical fiber sensors are mentioned. Examples of recent optical fiber sensors for the measurement of strain, temperature, displacement, air flow, pressure, liquid-level, magnetic field, and the determination of methadone, hydrocarbons, ethanol, and sucrose are briefly described.

  14. Development and testing of redundant optical fiber sensing systems with self-control, for underground nuclear waste disposal site monitoring. Vol. 1: Summary and evaluation. Final report

    International Nuclear Information System (INIS)

    Fiber optic sensors have been developed or further developed, for specific tasks of the research project reported, as for instance detecting and signalling changes of geophysical or geochemical parameters in underground waste storage sites which are of relevance to operating safety. Such changes include e.g. materials dislocations, extensions, temperatures, humidity, pH value and presence of gaseous carbon dioxide and hydrogen. The measuring principle chosen is the fiber Bragg Grating method, as a particularly versatile method easy to integrate into fiber optic networks. After development and successful lab-scale testing of all sensors, except for the gas sensors, field test systems have been made for underground applications and have been tested in situ in the experimental Konrad mine of DBE. Most of the problems discovered with these tests could be resolved within the given project period, so that finally field-test proven sensing systems are available for further activities. The report explains the system performance with a concrete example which shows inter alia beneficial aspects of the system with respect to on-site operation, and the potentials offered in establishing more direct connections between numerical safety analyses and measured results. (orig./CB)

  15. Photometric device using optical fibers

    International Nuclear Information System (INIS)

    Remote measurements in radioactive environment are now possible with optical fibers. Measurement instruments developed by CEA are constitued of: - an optical probe (5 mm to 1 meter optical path length), - a photometric measurement device, - optical fiber links. 'TELEPHOT' is a photometric device for industrial installations. It is uses interferentiel filters for 2 to 5 simultaneous wave lengths. 'CRUDMETER' measures the muddiness of water. It can be equipped with a high sensitivity cell of 50 cm optical path length tested up to 250 bars. Coupling a double beam spectrophotometer to a remote optical probe, up to 1 meter optical path length, is carried out by means of an optical device using optical fibers links, eventually several hundred meter long. For these equipments special step index large core fibers, 1 to 1.5 mm in diameter, have been developed as well connectors. For industrial control and research these instruments offer new prospect thanks to optical fibers use

  16. All-Fiber-Optic Gyroscopes

    Science.gov (United States)

    Kim, B. Y.; Shaw, H. J.

    1987-03-01

    The development of all-fiber-optic gyroscopes at Stanford University is reviewed. Fiber-optic components for the gyroscopes are described. Techniques to suppress various error sources, and different approaches to a linear scale factor with wide dynamic range, are discussed. Fiber-optic single sideband frequency shifters for closed-loop operation of gyroscopes are described. A new approach to high birefringence fiber gyroscopes, with broadband optical source and birefringence modulation, is presented. Other approaches, including the pulsed reentrant fiber gyro, are shown.

  17. Optical fiber synaptic sensor

    Science.gov (United States)

    Pisarchik, A. N.; Jaimes-Reátegui, R.; Sevilla-Escoboza, R.; García-Lopez, J. H.; Kazantsev, V. B.

    2011-06-01

    Understanding neuron connections is a great challenge, which is needed to solve many important problems in neurobiology and neuroengineering for recreation of brain functions and efficient biorobotics. In particular, a design of an optical synapse capable to communicate with neuron spike sequences would be crucial to improve the functionality of neuromimmetic networks. In this work we propose an optical synaptic sensor based on an erbium-doped fiber laser driven by a FitzHung-Nagumo electronic neuron, to connect with another electronic neuron. Two possible optical synaptic configurations are analyzed for optoelectronic coupling between neurons: laser cavity loss modulation and pump laser modulation. The control parameters of the proposed optical synapse provide additional degrees of flexibility to the neuron connection traditionally controlled only by coupling strengths in artificial networks.

  18. Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

    Science.gov (United States)

    Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

    2015-01-01

    This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS) and biosensors (FOBS). Fiber optic sensor (FOS) systems use the ability of optical fibers (OF) to guide the light in the spectral range from ultraviolet (UV) (180 nm) up to middle infrared (IR) (10 µm) and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors. PMID:26437407

  19. Formation and applications of nanoparticles in silica optical fibers

    CERN Document Server

    Blanc, Wilfried

    2015-01-01

    Optical fibers are the basis for applications that have grown considerably in recent years (telecommunications, sensors, fiber lasers, etc). Despite undeniable successes, it is necessary to develop new generations of amplifying optical fibers that will overcome some limitations typical of silica glass. In this sense, the amplifying Transparent Glass Ceramics (TGC), and particularly the fibers based on this technology, open new perspectives that combine the mechanical and chemical properties of a glass host with the augmented spectroscopic properties of embedded nanoparticles. This paper is an opportunity to make a state of the art on silica-based optical fibers containing nanoparticles of various types, particularly rare-earth-doped oxide nanoparticles, and on the methods for making such fibers. In the first section of this article, we will review basics on standard optical fibers and on nanoparticle-doped fibers. In the second section we will recall some fabrication methods used for standard optical fibers, ...

  20. Temperature-independent polymer optical fiber evanescent wave sensor

    OpenAIRE

    Zhong, Nianbing; Liao, Qiang; Zhu, Xun; Zhao, Mingfu; Yun HUANG; Chen, Rong

    2015-01-01

    Although the numerous advantages of polymer optical fibers have been exploited in the fields of sensors and telecommunications, such fibers still experience a critical problem: the temperature dependency. Therefore, we explored the temperature-independent operation of a polymer fiber-optic evanescent wave sensor immersed in distilled water. We investigated variations in the surface morphology, deformation trajectory, refractive index, and weight of the fiber-sensing region with varying water ...

  1. Anisotropic Metamaterial Optical Fibers

    CERN Document Server

    Pratap, Dheeraj; Pollock, Justin G; Iyer, Ashwin K

    2014-01-01

    Internal physical structure can drastically modify the properties of waveguides: photonic crystal fibers are able to confine light inside a hollow air core by Bragg scattering from a periodic array of holes, while metamaterial loaded waveguides for microwaves can support propagation at frequencies well below cutoff. Anisotropic metamaterials assembled into cylindrically symmetric geometries constitute light-guiding structures that support new kinds of exotic modes. A microtube of anodized nanoporous alumina, with nanopores radially emanating from the inner wall to the outer surface, is a manifestation of such an anisotropic metamaterial optical fiber. The nanopores, when filled with a plasmonic metal such as silver or gold, greatly increase the electromagnetic anisotropy. The modal solutions in anisotropic circular waveguides can be uncommon Bessel functions with imaginary orders.

  2. Fiber optic TV direct

    Science.gov (United States)

    Kassak, John E.

    1991-01-01

    The objective of the operational television (OTV) technology was to develop a multiple camera system (up to 256 cameras) for NASA Kennedy installations where camera video, synchronization, control, and status data are transmitted bidirectionally via a single fiber cable at distances in excess of five miles. It is shown that the benefits (such as improved video performance, immunity from electromagnetic interference and radio frequency interference, elimination of repeater stations, and more system configuration flexibility) can be realized if application of the proven fiber optic transmission concept is used. The control system will marry the lens, pan and tilt, and camera control functions into a modular based Local Area Network (LAN) control network. Such a system does not exist commercially at present since the Television Broadcast Industry's current practice is to divorce the positional controls from the camera control system. The application software developed for this system will have direct applicability to similar systems in industry using LAN based control systems.

  3. Optical fiber network : Cisco part

    OpenAIRE

    Lu CHEN

    2014-01-01

    This thesis describes a experimental optical fiber network. The thesis was based on the industrial placement work to design a laboratory network. The purpose of this thesis was to provide designs for setting an optical fiber network in the city of Kuopio. The project work was started by searching information and usable technology in the books from the library and the Internet. Most of the broadband and/or fiber optical networks use OSPF together with MPLS as their networking protocols. Th...

  4. Fiber-optic fluorescence imaging

    OpenAIRE

    Flusberg, Benjamin A; Cocker, Eric D; Piyawattanametha, Wibool; Jung, Juergen C; Cheung, Eunice L. M.; Schnitzer, Mark J

    2005-01-01

    Optical fibers guide light between separate locations and enable new types of fluorescence imaging. Fiber-optic fluorescence imaging systems include portable handheld microscopes, flexible endoscopes well suited for imaging within hollow tissue cavities and microendoscopes that allow minimally invasive high-resolution imaging deep within tissue. A challenge in the creation of such devices is the design and integration of miniaturized optical and mechanical components. Until recently, fiber-ba...

  5. Chemical Sensing Using Fiber Cavity Ring-Down Spectroscopy

    Directory of Open Access Journals (Sweden)

    Hans-Peter Loock

    2010-03-01

    Full Text Available Waveguide-based cavity ring-down spectroscopy (CRD can be used for quantitative measurements of chemical concentrations in small amounts of liquid, in gases or in films. The change in ring-down time can be correlated to analyte concentration when using fiber optic sensing elements that change their attenuation in dependence of either sample absorption or refractive index. Two types of fiber cavities, i.e., fiber loops and fiber strands containing reflective elements, are distinguished. Both types of cavities were coupled to a variety of chemical sensor elements, which are discussed and compared.

  6. Communicating On The Moon Via Fiber Optics

    Science.gov (United States)

    Lutes, George F.

    1992-01-01

    Report discusses feasibility of communicating over long distances on Moon via fiber optics. Compares fiber-optic and microwave technologies, concluding fiber optics offer less consumption of power, less weight, less bulk, and lower cost. Present commercial fiber-optic technology appears usable on Moon with minor modifications. Includes tutorial chapter on fiber-optic-communication technology and chapter on efforts to improve technology.

  7. Fiber optic light sensor.

    Science.gov (United States)

    Chudyk, Wayne; Flynn, Kyle F

    2015-06-01

    We describe a low-cost fiber optic sensor for measuring photosynthetically active radiation (PAR) in turbulent flow. Existing technology was combined in a novel way for probe development addressing the need for a small but durable instrument for use in flowing water. Optical components including fiber optics and a wide-spectrum light detector were used to separate light collection from electronic detection so that measurements could be completed in either the field or laboratory, in air or underwater. Connection of the detector to Arduino open-source electronics and a portable personal computer (PC) enabled signal processing and allowed data to be stored in a spreadsheet for ease of analysis. Calibration to a commercial cosine-corrected instrument showed suitable agreement with the added benefit that the small sensor face allowed measurements in tight spaces such as close to the streambed or within leafy or filamentous plant growth. Subsequently, we applied the probe in a separate study where over 35 experiments were successfully completed to characterize downward light attenuation in filamentous algae in turbulent flow. PMID:26009160

  8. Optimize Etching Based Single Mode Fiber Optic Temperature Sensor

    OpenAIRE

    Ajay Kumar; Dr. Pramod Kumar

    2014-01-01

    This paper presents a description of etching process for fabrication single mode optical fiber sensors. The process of fabrication demonstrates an optimized etching based method to fabricate single mode fiber (SMF) optic sensors in specified constant time and temperature. We propose a single mode optical fiber based temperature sensor, where the temperature sensing region is obtained by etching its cladding diameter over small length to a critical value. It is observed that th...

  9. Investigations on birefringence effects in polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Hu, Xiaolian; Saez-Rodriguez, D.; Bang, Ole; Webb, D. J.; Caucheteur, C.

    2014-01-01

    Step-index polymer optical fiber Bragg gratings (POFBGs) and microstructured polymer optical fiber Bragg gratings (mPOFBGs) present several attractive features, especially for sensing purposes. In comparison to FBGs written in silica fibers, they are more sensitive to temperature and pressure because of the larger thermo-optic coefficient and smaller Young's modulus of polymer materials. (M)POFBGs are most often photowritten in poly(methylmethacrylate) (PMMA) materials using a continuous-wave 32...

  10. Optical Fiber Sensors for Smart Structures : A Review

    Directory of Open Access Journals (Sweden)

    P. Kundu

    1996-10-01

    Full Text Available This review describes recent advances in optical fiber sensors for smart structures. After discussing the fabrication on technology and strain sensing of fiber-optic sensors in a brief introduction, the detailed accounts of signal processing techniques employed in them are given. The application areas of fiber-optic sensors are also described briefly with necessary references. Future trend of work is indicated in the concluding remarks.

  11. Temperature sensing on tapered single mode fiber using mechanically induced long period fiber gratings

    Science.gov (United States)

    Marrujo-García, Sigifredo; Velázquez-González, Jesús Salvador; Pulido-Navarro, María. Guadalupe; González-Ocaña, Ernesto; Mújica-Ascencio, Saúl; Martínez-Piñón, Fernando

    2015-09-01

    The modeling of a temperature optical fiber sensor is proposed and experimentally demonstrated in this work. The suggested structure to obtain the sensing temperature characteristics is by the use of a mechanically induced Long Period Fiber Grating (LPFG) on a tapered single mode optical fiber. A biconical fiber optic taper is made by applying heat using an oxygen-propane flame burner while stretching the single mode fiber (SMF) whose coating has been removed. The resulting geometry of the device is important to analyze the coupling between the core mode to the cladding modes, and this will determine whether the optical taper is adiabatic or non-adiabatic. On the other hand, the mechanical LPFG is made up of two plates, one grooved and other flat, the grooved plate was done on an acrylic slab with the help of a computerized numerical control machine (CNC). In addition to the experimental work, the supporting theory is also included.

  12. Optical Sensors Based on Plastic Fibers

    Directory of Open Access Journals (Sweden)

    Rogério Nogueira

    2012-09-01

    Full Text Available The recent advances of polymer technology allowed the introduction of plastic optical fiber in sensor design. The advantages of optical metrology with plastic optical fiber have attracted the attention of the scientific community, as they allow the development of low-cost or cost competitive systems compared with conventional technologies. In this paper, the current state of the art of plastic optical fiber technology will be reviewed, namely its main characteristics and sensing advantages. Several measurement techniques will be described, with a strong focus on interrogation approaches based on intensity variation in transmission and reflection. The potential applications involving structural health monitoring, medicine, environment and the biological and chemical area are also presented.

  13. Sensing properties of periodic stack of nano-films deposited with various vapor-based techniques on optical fiber end-face

    Science.gov (United States)

    Koba, Marcin; Ró?ycki-Bakon, Rados?aw; Firek, Piotr; ?mietana, Mateusz

    2015-07-01

    This work presents a study on sensing capabilities of stacks of nano-films deposited on a single-mode optical fiber end-faces. The stacks consist of periodically interchanging thin-film layers of materials characterized by different refractive indices (RI). The number of layers is relatively small to encourage light-analyte interactions. Two different deposition techniques are considered, i.e., radio frequency plasma enhanced chemical vapor deposition (RF PECVD) and physical vapor deposition by reactive magnetron sputtering (RMS). The former technique allows to deposit stacks consisting of silicon nitride nano-films, and the latter is well suited for aluminum and titanium oxides alternating layers. The structures are tested for external RI and temperature measurements.

  14. Simulation of a surface plasmon resonance-based fiber-optic sensor for gas sensing in visible range using films of nanocomposites

    International Nuclear Information System (INIS)

    A surface plasmon resonance-based fiber-optic sensor coated with nanocomposite film for sensing small concentrations of gases in the visible region of the electromagnetic spectrum has been analyzed. The nanocomposites considered are nanoparticles of Ag, Au and indium tin oxide (ITO) with their varying fraction dispersed in the host dielectric matrix of WO3, SnO2 and TiO2. For analysis, the effective indices of nanocomposites are calculated by adopting the Maxwell–Garnett model for nanoparticles of dimensions much smaller than the wavelength of radiation used for investigation. The effects of the volume fraction of nanoparticles in different nanocomposites and the thickness of the nanocomposite layer on the sensitivity of the sensor have been studied. It has been found that the sensor with the ITO–TiO2 coated nanocomposite with a small volume fraction and optimized film thickness possesses higher sensitivity

  15. Restraint-free wearable sensing clothes using a hetero-core optic fiber for measurements of arm motion and walking action

    Science.gov (United States)

    Nishiyama, Michiko; Sasaki, Hiroyuki; Watanabe, Kazuhiro

    2007-04-01

    In recent years, unrestrained monitoring human posture and action is a field of increasing interest in the welfare of the elderly and the sport-biomechanics. The scope is this study is that we develop a wearable sensing clothes, which can detect entire body posture and motion using a hetero-core optic fiber sensor. This newly developed sensor can offers several advantages such as the simplicity of structure and fabrication, the stable single mode based operation, the temperature independent property, and the precise loss controllability on given macro bending. These properties are suitable for implementing unrestrained wearable clothes. In this paper, for monitoring flexion of joint without the disturbance of the rucks in the clothes, we proposed and fabricated the improved module structured in the joint ranging 0-90 degree. Additionally, in order to reduce the number of transmission line to be added due to monitoring the whole body posture and motion, we tested that two hetero-core sensors which are tandem placed in a single transmission line have been discriminated by the temporal differential of the optical loss. As a result, we have successfully demonstrated that the wearable sensing clothes could monitor arm motion and human walking without restraint to human daily behavior.

  16. Fluorescing optical fibers and uses

    International Nuclear Information System (INIS)

    Present available industrial Plastic Optical Fibers are made of an optical core of either Poly Methyl Methacrylate, Polystyrene, or Polycarbonate. Three main fiber families are produced: - transparent fibers, used to transmit light or signals; - scintillating fibers, doped with two or more dopants to let them able to detect particles by radiating blue or green light, measured with a photomultiplier; - fluorescent fibers, doped with a single dopant, and able to shift the ambient incident radiation into another radiation of longer wavelength. New PS core fluorescent fibers are made so far with different absorption and fluorescent reemission wavelength bands. Some optical characteristics of the materials employed for blue, green, yellow, orange fibers are described. Applications in the light sensors field already exist such as light intensity detectors for electric arcs, fog or particle detectors

  17. Fundamentals of plastic optical fibers

    CERN Document Server

    Koike, Yasuhiro

    2014-01-01

    Polymer photonics is an interdisciplinary field which demands excellence both in optics (photonics) and materials science (polymer). However, theses disciplines have developed independently, and therefore the demand for a comprehensive work featuring the fundamentals of photonic polymers is greater than ever.This volume focuses on Polymer Optical Fiber and their applications. The first part of the book introduces typical optical fibers according to their classifications of material, propagating mode, and structure. Optical properties, the high bandwidth POF and transmission loss are discussed,

  18. Fiber-diffraction Interferometer using Coherent Fiber Optic Taper

    OpenAIRE

    Kihm, Hagyong; Lee, Yun-Woo

    2010-01-01

    We present a fiber-diffraction interferometer using a coherent fiber optic taper for optical testing in an uncontrolled environment. We use a coherent fiber optic taper and a single-mode fiber having thermally-expanded core. Part of the measurement wave coming from a test target is condensed through a fiber optic taper and spatially filtered from a single-mode fiber to be reference wave. Vibration of the cavity between the target and the interferometer probe is common to bot...

  19. Fiber optic sensor and method for making

    Science.gov (United States)

    Vartuli, James Scott; Bousman, Kenneth Sherwood; Deng, Kung-Li; McEvoy, Kevin Paul; Xia, Hua

    2010-05-18

    A fiber optic sensor including a fiber having a modified surface integral with the fiber wherein the modified surface includes an open pore network with optical agents dispersed within the open pores of the open pore network. Methods for preparing the fiber optic sensor are also provided. The fiber optic sensors can withstand high temperatures and harsh environments.

  20. Integrated optical fiber shape sensor modules based on twisted multicore fiber grating arrays

    Science.gov (United States)

    Westbrook, P. S.; Feder, K. S.; Kremp, T.; Taunay, T. F.; Monberg, E.; Kelliher, J.; Ortiz, R.; Bradley, K.; Abedin, K. S.; Au, D.; Puc, G.

    2014-02-01

    In this paper we report on the development of a complete integrated optical fiber assembly suitable for shape sensing. Our shape sensor module consists of a length (>1m) of twisted multicore optical fiber with fiber Bragg gratings inscribed along its length. Our fiber has a compact 180 micron coated diameter, a twist of 50 turns per meter and grating reflectivities greater than 0.01% per cm of array, suitable for high efficiency scatter measurements over many meters of fiber. Single core to multicore fanouts and low reflectivity fiber termination are used to terminate the end of the array.

  1. Fiber optic combiner and duplicator

    Science.gov (United States)

    1979-01-01

    The investigation of the possible development of two optical devices, one to take two images as inputs and to present their arithmetic sum as a single output, the other to take one image as input and present two identical images as outputs is described. Significant engineering time was invested in establishing precision fiber optics drawing capabilities, real time monitoring of the fiber size and exact measuring of fiber optics ribbons. Various assembly procedures and tooling designs were investigated and prototype models were built and evaluated that established technical assurance that the device was feasible and could be fabricated. Although the interleaver specification in its entirety was not achieved, the techniques developed in the course of the program improved the quality of images transmitted by fiber optic arrays by at least an order of magnitude. These techniques are already being applied to the manufacture of precise fiber optic components.

  2. AGV guidance by fiber optic tactility

    Science.gov (United States)

    Djordjevich, Alexandar; Tso, Shiu K.; Zhu, H. Y.; Pjevalica, V.

    1999-11-01

    In order to increase the tactile sensing range and allow larger AGV speeds that result in larger vehicle stopping distances, the recently reported fiber-optic 'curvature gauges' sensitized to their geometric curvature are arranged in loops around the AGV. When the AGV is driven into other objects, these loops deform, resulting in the change of their curvature - which is registered. While many different types of bumpers and whiskers have been sued in the past for a similar purpose, the key difference here is that no intermediate mechanical elements are employed to either transfer the impact loads onto the sensitive element or provide compliance to it. Optical fibers themselves provide both functions simultaneously. As a result, tactility is achieved within a comparatively large range extending over 10 cm. Throughout this range, virtually no reaction forces are generated with the impacting body. The range mentioned is on top of the one provided by the more traditional elastic bumper the optical fibers are mounted on.

  3. Data acquisition with fiber optic sensors

    Science.gov (United States)

    Kist, R.

    The advantages of using fiber optic sensors for data acquisition are discussed, and their present utilization in this area is examined. Because of their high cost, these sensors are not likely to be competitive in general metrological applications in the near future. They do, however, provide important advantages in specific areas such as isolation against high voltage and immunity against electromagnetic fields and explosive and/or corrosive environments. They also offer the possibility of miniaturized and compact packaging of the sensing element an application within a broad temperature range. Multimode fiber optic sensors for parameters such as temperature, pressure, and refractive index have more immediate commercial potential than monomode fiber optic sensors, which have higher costs. The latter allow for high precision solutions of metrological tasks under specific conditions, and will be utilized in the foreseeable future.

  4. Fiber optic hydrogen sensor

    Energy Technology Data Exchange (ETDEWEB)

    Butler, M.A.; Sanchez, R.; Dulleck, G.R.

    1996-05-01

    This report covers the development of fiber optic hydrogen and temperature sensors for monitoring dissolved hydrogen gas in transformer oil. The concentration of hydrogen gas is a measure of the corona and spark discharge within the transformer and reflects the state of health of the transformer. Key features of the instrument include use of palladium alloys to enhance hydrogen sensitivity, a microprocessor controlled instrument with RS-232, liquid crystal readout, and 4-20 ma. current loop interfaces. Calibration data for both sensors can be down loaded to the instrument through the RS-232 interface. This project was supported by the Technology Transfer Initiative in collaboration with J. W. Harley, Inc. through the mechanism of a cooperative research and development agreement (CRADA).

  5. Evaluation of the heat-storage capability of shallow aquifers using active heat tracer tests and Fiber-Optics Distributed-Temperature-Sensing

    Science.gov (United States)

    Suibert Oskar Seibertz, Klodwig; Chirila, Marian Andrei; Bumberger, Jan; Dietrich, Peter; Vienken, Thomas

    2015-04-01

    In the course of the energy transition, geothermal energy storage and heat generation and cooling have proven to be environmental friendly alternatives to conventional energy. However, to ensure sustain usage, the heat transport behavior of aquifers and its distribution has to be studied. A tool to achieve this is the active heat tracer test, eg. Leaf et al. (2012). If active heat tracer tests are combined with in aquifer heat testing via electric heating-cables, eg. Liu et al. (2013), it is possible to observe heat transport and temperature signal decay without disturbing the original pressure field within the aquifer. In this field study a two channel High-Resolution-Fiber-Optic-Distributed-Temperature-Sensing and Pt100 were used to measure temperature signals within in two wells of 1.4 m distance, where the temperature difference was generated using a self regulating heating cable in the upstream well. High resolution Distributed-Temperature-Sensing measurements were achieved by coiling the fiber around screened plastic tubes. The upstream well was also used to observe heating (? Tmax approx. 24K) and temperature signal decay, while the downstream well was used to observe heat transport between both wells. The data was analyzed and compared to thermal conductivity of soil samples and Direct-Push (DP) Electrical-Conductivity-Logging and DP Hydraulic-Profiling results. The results show good agreement between DP data and temperature measurements proving the active heat tracer test is a suitable tool for providing reliable information on aquifer heat-storage capability. References Leaf, A.T., Hart, D.J., Bahr, J.M.: Active Thermal Tracer Tests for Improved Hydrostratigraphic Characterization. Ground Water, vol. 50, 2012 Liu, G., Knobbe, S., Butler, J.J.Jr.: Resolving centimeter-scale flows in aquifers and their hydrostratigraphic controls. Geophysical Research Letters, vol. 40, 2013

  6. Fiber optic-based biosensor

    Science.gov (United States)

    Ligler, Frances S.

    1991-01-01

    The NRL fiber optic biosensor is a device which measures the formation of a fluorescent complex at the surface of an optical fiber. Antibodies and DNA binding proteins provide the mechanism for recognizing an analyze and immobilizing a fluorescent complex on the fiber surface. The fiber optic biosensor is fast, sensitive, and permits analysis of hazardous materials remote from the instrumentation. The fiber optic biosensor is described in terms of the device configuration, chemistry for protein immobilization, and assay development. A lab version is being used for assay development and performance characterization while a portable device is under development. Antibodies coated on the fiber are stable for up to two years of storage prior to use. The fiber optic biosensor was used to measure concentration of toxins in the parts per billion (ng/ml) range in under a minute. Immunoassays for small molecules and whole bacteria are under development. Assays using DNA probes as the detection element can also be used with the fiber optic sensor, which is currently being developed to detect biological warfare agents, explosives, pathogens, and toxic materials which pollute the environment.

  7. Single-end simultaneous temperature and strain sensing techniques based on Brillouin optical time domain reflectometry in few-mode fibers.

    Science.gov (United States)

    Weng, Yi; Ip, Ezra; Pan, Zhongqi; Wang, Ting

    2015-04-01

    Recently there is a growing interest in developing few-mode fiber (FMF) based distributed sensors, which can attain higher spatial resolution and sensitivity compared with the conventional single-mode approaches. However, current techniques require two lightwaves injected into both ends of FMF, resulting in their complicated setup and high cost, which causes a big issue for geotechnical and petroleum applications. In this paper, we present a single-end FMF-based distributed sensing system that allows simultaneous temperature and strain measurement by Brillouin optical time-domain reflectometry (BOTDR) and heterodyne detection. Theoretical analysis and experimental assessment of multi-parameter discriminative measurement techniques applied to distributed FMF sensors are presented. Experimental results confirm that FM-BOTDR has similar performance with two-end methods such as FM-BOTDA, but with simpler setup and lower cost. The temperature-induced expansion strain (TIES) in response to different modes is discussed as well. Furthermore, we optimized the FMF design by exploiting modal profile and doping concentration, which indicates up to fivefold enhancement in measurement accuracy. This novel distributed FM-sensing system endows with good sensitivity characteristics and can prevent catastrophic failure in many applications. PMID:25968738

  8. Spatial and temporal resolution requirements for quench detection in (RE)Ba2Cu3Ox magnets using Rayleigh-scattering-based fiber optic distributed sensing

    Science.gov (United States)

    Chan, W. K.; Flanagan, G.; Schwartz, J.

    2013-10-01

    One of the key remaining challenges to safe and reliable operation of large, high temperature superconductor (HTS)-based magnet systems is quench detection and protection. Due to the slow quench propagation in HTS systems, the conventional discrete voltage-tap approach developed for NbTi and Nb3Sn magnets may not be sufficient. In contrast, a distributed temperature profile, generated by a distributed temperature sensor and facilitating continuous monitoring of the temperature at any monitored locations within a magnet with high spatial resolution, may be required. One such distributed temperature sensing option is the use of Rayleigh-based fiber optic sensors (FOS), which are immune to electromagnetic interference. The detection of a quench via Rayleigh-based FOS relies on converting the spectral shifts in the Rayleigh scattering spectra into temperature variations. As a result, the higher the spatial sampling resolution the larger the data processing volume, and thus the lower the temporal sampling resolution. So, for effective quench detection, which requires the quick and accurate identification of a hot spot, it is important to find a balance between the spatial and temporal resolutions executable on a given data acquisition and processing (DAQ) system. This paper discusses a method for finding an appropriate DAQ technology that matches the characteristic of a superconducting coil, and determining the acceptable resolutions for efficient and safe quench detection. A quench detection algorithm based on distributed temperature sensing is proposed and its implementation challenges are discussed.

  9. Temperature Response of a Small Mountain Stream to Thunderstorm Cloud-Cover: Application of DTS Fiber-Optic Temperature Sensing

    Science.gov (United States)

    Thayer, D.; Klatt, A. L.; Miller, S. N.; Ohara, N.

    2014-12-01

    From a hydrologic point of view, the critical zone in alpine areas contains the first interaction of living systems with water which will flow to streams and rivers that sustain lowland biomes and human civilization. A key to understanding critical zone functions is understanding the flow of energy, and we can measure temperature as a way of looking at energy transfer between related systems. In this study we installed a Distributed Temperature Sensor (DTS) and fiber-optic cable in a zero-order stream at 9,000 ft in the Medicine Bow National Forest in southern Wyoming. We measured the temperature of the stream for 17 days from June 29 to July 16; the first 12 days were mostly sunny with occasional afternoon storms, and the last 5 experienced powerful, long-lasting storms for much of the day. The DTS measurements show a seasonal warming trend of both minimum and maximum stream temperature for the first 12 days, followed by a distinct cooling trend for the five days that experienced heavy storm activity. To gain insights into the timing and mechanisms of energy flow through the critical zone systems, we analyzed the timing of stream temperature change relative to solar short-wave radiation, and compared the stream temperature temporal response to the temporal response of soil temperature adjacent to the stream. Since convective thunderstorms are a dominant summer weather pattern in sub-alpine regions in the Rocky Mountains, this study gives us further insight into interactions of critical zone processes and weather in mountain ecosystems.

  10. Fiber laser systems for space lasercom and remote sensing

    Science.gov (United States)

    Gupta, Shantanu; Engin, Doruk; Puffenberger, Kent; Litvinovich, Slava; Kimpel, Frank; Utano, Rich

    2013-09-01

    Space based laser remote-sensing for Earth observation and planetary atmospheres has traditionally relied on the mature diode-pumped solid-state laser and nonlinear frequency conversion technology. We highlight representative examples, including ongoing space mission programs at Fibertek. Key design issues are highlighted, and the lessons learned from a multi-disciplinary design process addressing the space-qualification requirements. Fiber laser/amplifier system provides an agile optical platform for space based laser applications ? space lasercom, space-based Earth (or planetary) remote sensing, and space-based imaging. In particular we discuss ongoing efforts at Fibertek on a space-qualifiable, high-performance 1.5-?m Er-doped fiber laser transmitter for inter-planetary lasercom. Design and performance for space qualification is emphasized. As an example of an agile laser platform, use of above fiber laser/amplifier hardware platform for space based sensing of atmospheric CO2 is also highlighted.

  11. Simultaneous single-fiber communications and linear position sensing

    Science.gov (United States)

    Fuhr, Peter L.; Kajenski, Peter J.; Huston, Dryver J.; Spillman, William B.

    1992-02-01

    The use of a single multimode optical fiber is investigated for simultaneous high-data-rate optical communications and linear displacement sensing. The technique is based on and an extension of the combination of single analog tone frequency and modal-domain vibration sensing. Digital pseudorandom-bit sequences are employed for the data transmission at several standard telecommunication speeds. The position of an in-line fiberoptic displacement sensor is determined by examining variations in the data-stream bit-error rate for the cases of both static and dynamic displacements. It is shown that a single multimode fiber can be utilized simultaneously as both a linear-displacement sensor and a communication link. Fiber faults can be located to a resolution of 3 m at the 34-Mbaud rate, and the cost-effectiveness of multiplexing sensor and communications systems is noted.

  12. Classification of Fiber Optical Sensors

    Directory of Open Access Journals (Sweden)

    Shivang Ghetia

    2013-07-01

    Full Text Available Fiber optics sensor technology offers different parameter measurements such as strain, pressure, temperature, current and many more things. For that different type of sensors are used and these sensors converts these parameters to optical parameters like light intensity or phase or polarization of light. These converted parameters are transmitted using an optical link over a long distance. In this paper, we review optical sensors and their applications. Here, we describe the classification of fiber optic sensors and based on these sensors, some applications of them are discussed.

  13. Silica optical fibers: technology update

    Science.gov (United States)

    Krohn, David A.; McCann, Brian P.

    1995-05-01

    Silica-core optical fibers have long been the standard delivery medium for medical laser delivery systems. Their high strength, excellent flexibility, and low cost continue to make them the fiber of choice for systems operating from 300 to 2200 nm. An overview of the current fiber constructions available to the industry is reviewed. Silicone-clad fibers, hard- fluoropolymer clad fibers and silica-clad fibers are briefly compared in terms of mechanical and optical properties. The variety of fiber coatings available is also discussed. A significant product development of silica fiber delivery systems has been in side-firing laser delivery systems for Urology. These devices utilize silica-core fibers to project the laser energy at a substantial lateral angle to the conventional delivery system, typically 40 to 100 degrees off axis. Many unique distal tips have been designed to meet the needs of this potentially enormous application. There are three primary technologies employed in side-firing laser delivery systems: reflection off of an attached medium; reflection within an angle-polished fiber through total internal reflection; and reflection from both an angle-polished fiber and an outside medium. Each technology is presented and compared on the basis of operation modality, transmission efficiency, and power-handling performance.

  14. Fiber optic pressure sensors for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hashemian, H.M.; Black, C.L. [Analysis and Measurement Services Corp., Knoxville, TN (United States)

    1995-04-01

    In the last few years, the nuclear industry has experienced some problems with the performance of pressure transmitters and has been interested in new sensors based on new technologies. Fiber optic pressure sensors offer the potential to improve on or overcome some of the limitations of existing pressure sensors. Up to now, research has been motivated towards development and refinement of fiber optic sensing technology. In most applications, reliability studies and failure mode analyses remain to be exhaustively conducted. Fiber optic sensors have currently penetrated certain cutting edge markets where they possess necessary inherent advantages over other existing technologies. In these markets (e.g. biomedical, aerospace, automotive, and petrochemical), fiber optic sensors are able to perform measurements for which no alternate sensor previously existed. Fiber optic sensing technology has not yet been fully adopted into the mainstream sensing market. This may be due to not only the current premium price of fiber optic sensors, but also the lack of characterization of their possible performance disadvantages. In other words, in conservative industries, the known disadvantages of conventional sensors are sometimes preferable to unknown or not fully characterized (but potentially fewer and less critical) disadvantages of fiber optic sensors. A six-month feasibility study has been initiated under the auspices of the US Nuclear Regulatory Commission (NRC) to assess the performance and reliability of existing fiber optic pressure sensors for use in nuclear power plants. This assessment will include establishment of the state of the art in fiber optic pressure sensing, characterization of the reliability of fiber optic pressure sensors, and determination of the strengths and limitations of these sensors for nuclear safety-related services.

  15. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren; Bang, Ole

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer.

  16. Optical Fiber Grating based Sensors

    OpenAIRE

    Michelsen, Susanne; Henningsen, Jes; Kristensen, Martin

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response ...

  17. Optical Fiber Grating based Sensors

    OpenAIRE

    Michelsen, Susanne

    2006-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response ...

  18. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is ...

  19. High Precision Displacement Measurement Using Fiber Optics

    CERN Document Server

    Berkovic, G; Scandale, Walter; Shafir, E; Todesco, Ezio

    2002-01-01

    We describe laboratory experiments with a fiber-optic sensor employing a chirped laser that detects, with 20-30 micrometer accuracy, displacements of a remote reflective target at distance of 200-500 mm. The requirements of chirp linearity and laser coherence in order to achieve this sensitivity are elaborated. This sensor can be employed for remotely sensing minute displacements of objects in harsh environments, including cryo-magnets in particle accelerators.

  20. Microstructured optical fiber refractive index sensor

    DEFF Research Database (Denmark)

    Town, Graham E.; McCosker, Ravi; Yuan, Scott Wu; Bang, Ole

    2010-01-01

    We describe a dual-core microstructured optical fiber designed for refractive index sensing of fluids. We show that by using the exponential dependence of intercore coupling on analyte refractive index, both large range and high sensitivity can be achieved in the one device. We also show that selective filling of the microstructure with analyte can increase the device sensitivity by approximately 1 order of magnitude.

  1. Mobile fiber optic emission spectrograph

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, W.A.; Coleman, C.J.; McCarty, J.E.; Beck, R.S.

    1997-05-01

    Technical Assistance Request HLW/DWPF-TAR-970064 asked SRTC to evaluate the use of a fiber optic coupled emission spectrometer. The spectrometer would provide additional ICP analyses in the DWPF laboratory.

  2. Respiratory function monitoring using a real-time three-dimensional fiber-optic shaping sensing scheme based upon fiber Bragg gratings

    OpenAIRE

    Allsop, T.; Bhamber, R.; LLOYD, G.; Miller, M. R.; Dixon, A.; Webb, D; Ania Castañón, Juan Diego; Bennion, I (Ian)

    2012-01-01

    An array of in-line curvature sensors on a garment is used to monitor the thoracic and abdominal movements of a human during respiration. The results are used to obtain volumetric changes of the human torso in agreement with a spirometer used simultaneously at the mouth. The array of 40 in-line fiber Bragg gratings is used to produce 20 curvature sensors at different locations, each sensor consisting of two fiber Bragg gratings. The 20 curvature sensors and adjoining fiber are encapsulated in...

  3. Optimize Etching Based Single Mode Fiber Optic Temperature Sensor

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2014-02-01

    Full Text Available This paper presents a description of etching process for fabrication single mode optical fiber sensors. The process of fabrication demonstrates an optimized etching based method to fabricate single mode fiber (SMF optic sensors in specified constant time and temperature. We propose a single mode optical fiber based temperature sensor, where the temperature sensing region is obtained by etching its cladding diameter over small length to a critical value. It is observed that the light transmission through etched fiber at 1550 nm wavelength optical source becomes highly temperature sensitive, compared to the temperature insensitive behavior observed in un-etched fiber for the range on 30ºC to 100ºC at 1550 nm. The sensor response under temperature cycling is repeatable and, proposed to be useful for low frequency analogue signal transmission over optical fiber by means of inline thermal modulation approach.

  4. Innovative Plastic Optical Fiber Sensors

    OpenAIRE

    Casalicchio, Maria Luisa

    2012-01-01

    This thesis describes the development of new types of fiber optic sensors for the measurement of mechanical quantities such as displacement, vibration and acceleration. Also, it describes the realization of specific acquisition systems designed to interrogate the developed sensors. Since optical fibers have been historically associated with high speed telecommunication links because of their very large bandwidth and low attenuation, there is a great interest for their employment in sensor app...

  5. Small Business Innovations (Fiber Optics)

    Science.gov (United States)

    1991-01-01

    Foster-Miller, Inc. Waltham, MA developed the In-Situ Fiber Optic Polymer Reaction Monitor which could lead to higher yields and lower costs in complex composite manufacturing. The monitor, developed under a Small Business Innovation Research (SBIR) contract with Langley Research Center, uses an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. It is the first analytical system capable of directly measuring the chemistry of advanced composite materials.

  6. Utilization of Infrared Fiber Optic in the Automotive Industry

    Science.gov (United States)

    Tucker, Dennis S.; Brantley, Lott W. (Technical Monitor)

    2001-01-01

    Fiber optics are finding a place in the automotive industry. Illumination is the primary application today. Soon, however, fiber optics will be used for data communications and sensing applications. Silica fiber optics and plastic fibers are sufficient for illumination and communication applications however, sensing applications involving high temperature measurement and remote gas analysis would benefit from the use of infrared fiber optics. Chalcogonide and heavy metal fluoride glass optical fibers are two good candidates for these applications. Heavy metal fluoride optical fibers are being investigated by NASA for applications requiring transmission in the infrared portion of the electromagnetic spectrum. Zirconium-Barium-Lanthanum-Aluminum-Sodium-Fluoride (ZBLAN) is one such material which has been investigated. This material has a theoretical attenuation coefficient 100 times lower than that of silica and transmits into the mid-IR. However, the measured attenuation coefficient is higher than silica due to impurities and crystallization. Impurities can be taken care of by utilizing cleaner experimental protocol. It has been found that crystallization can be suppressed by processing in reduced gravity. Fibers processed in reduced gravity on the KC135 reduced gravity aircraft were found to be free of crystals while those processed on the ground were found to have crystals. These results will be presented along with plans for producing continuous lengths of ZBLAN optical fiber on board the International Space Station.

  7. Power system applications of fiber optic sensors

    Science.gov (United States)

    Johnston, A. R.; Jackson, S. P.; Kirkham, H.; Yeh, C.

    1986-01-01

    This document is a progress report of work done in 1985 on the Communications and Control for Electric Power Systems Project at the Jet Propulsion Laboratory. These topics are covered: Electric Field Measurement, Fiber Optic Temperature Sensing, and Optical Power transfer. Work was done on the measurement of ac and dc electric fields. A prototype sensor for measuring alternating fields was made using a very simple electroscope approach. An electronic field mill sensor for dc fields was made using a fiber optic readout, so that the entire probe could be operated isolated from ground. There are several instances in which more precise knowledge of the temperature of electrical power apparatus would be useful. This report describes a number of methods whereby the distributed temperature profile can be obtained using a fiber optic sensor. The ability to energize electronics by means of an optical fiber has the advantage that electrical isolation is maintained at low cost. In order to accomplish this, it is necessary to convert the light energy into electrical form by means of photovoltaic cells. JPL has developed an array of PV cells in gallium arsenide specifically for this purpose. This work is described.

  8. Fiber Ring Optical Gyroscope (FROG)

    Science.gov (United States)

    1979-01-01

    The design, construction, and testing of a one meter diameter fiber ring optical gyro, using 1.57 kilometers of single mode fiber, are described. The various noise components: electronic, thermal, mechanical, and optical, were evaluated. Both dc and ac methods were used. An attempt was made to measure the Earth rotation rate; however, the results were questionable because of the optical and electronic noise present. It was concluded that fiber ring optical gyroscopes using all discrete components have many serious problems that can only be overcome by discarding the discrete approach and adapting an all integrated optic technique that has the laser source, modulator, detector, beamsplitters, and bias element on a single chip.

  9. Fiber optics in meteorological instrumentation suites

    Science.gov (United States)

    Holton, Carvel E.; Parker, Matthew J.

    1999-12-01

    Standard meteorological sensors and sensor suites used for weather and environmental monitoring are currently based primarily on electronic instrumentation that is frequently susceptible to destruction and/or interruption from natural (e.g. lightning) and man-made sources of Electromagnetic Interference (EMI). The cost of replacement or shielding of these systems is high in terms of frequency of replacement and the incipient capital cost. Sensors based on optical fibers have been developed in sufficient variety as to allow the development of full meteorological instrumentation suitess based on individual or multiplexed optical fiber sensors. Examples of sensing functions which can be implemented using optical fibers include: wine speed (cup anemometers & Doppler lidars), wind direction (vanes & lidars), temperature, humidity, barometric pressure, accumulated precipitation and precipitation rate (fiber lidar). Suites of such sensors are capable of using little or no electronics in the environmentally exposed regions, substantially reducing system EMI susceptibility and adding functional capability. The current presentation seeks to explore options available in such meteorological suites and examine the issues in their design and deployment. Performance data on several newer fiber sensors suitable to meteorological use will be presented and discussed.

  10. Using high-resolution fiber-optic distributed temperature sensing to measure spatially resolved speed and temperature of airflows in a shallow gully

    Science.gov (United States)

    Thomas, Christoph; Sayde, Chadi; Selker, John

    2015-04-01

    We present a novel observational technique that was applied to study transient shallow cold-air drainages and pools in undulating terrain in weak-wind conditions. Wind speed and air temperature at thousands of closely co-located locations were measured simultaneously at high spatial (0.25m) and temporal (5s) resolution using paired passive and actively heated optical fibers with a distributed temperature sensing system (DTS). The fibers were deployed in a transect across a shallow gully with a total length of 230 m at three levels (0.5, 1, and 2m above ground level) during the Shallow Cold Pool (SCP) Experiment in Northern Colorado, USA in October and November 2012. While we previously demonstrated that air temperature and the thermal structure of the near-surface turbulence can be observed with the DTS technique (Thomas et al., 2012, Zeeman et al., 2014), the novelty here consists of additionally measuring wind speed on horizontal scales of several hundreds of meters with fine resolution. Analogous to a hot-wire anemometer, the approach is based on the principal of velocity-dependent heat transfer from a heated surface. We present the theoretical basis for the DTS wind and temperature measurements and validate it against point observations from sonic anemometers and thermo-hygrometers. A space-time analysis of the near-surface gully flow and temperature field is presented based upon the observations subject to an orthogonal multi-resolution decomposition for selected cases. The temporal variability of near-surface air temperature was largest half-way up the slope caused be shifts of the very sharp thermal boundary between the density driven cold-air drainage flow in the gully bottom and the lower density air on the slopes, which was significantly warmed by enhanced downward mixing of sensible heat in the lee of the gully shoulder. Stationary horizontal temperature gradients at this thermal boundary amounted to 6 to 8 K m-1 and persisted for several hours unless the cold-air pool was displaced from the gully by intermittently strong external wind forcing. Even gentle surface heterogeneity can have dramatic impacts on the structure of the near-surface flow, turbulence, and heat transport, which calls for spatial observations to quantify and compensate for the location bias of traditional single-point flow and flux measurements. The novel approach, which allows studying the spatial structure of the surface layer on scales spanning four orders of magnitude (0.1 - 1000m), opens up many important opportunities for testing fundamental assumptions and concepts in micrometeorology including, but not limited to turbulent length scales, the validity of Taylors hypothesis and ergodicity, surface heterogeneity, and internal boundary layers. References: Thomas, C.K., Kennedy, A.M., Selker, J.S., Moretti, A., Schroth, M.H., Smoot, A.R., Tufillaro, N.B., Zeeman, M.J., 2012. High-resolution fibre-optic temperature sensing: A new tool to study the two-dimensional structure of atmospheric surface layer flow. Boundary-Layer Meteorol. 142, 177-192. DOI: 10.1007/s10546-011-9672-7 Zeeman MJ, Selker JS, Thomas CK. Near-surface motion in the nocturnal, stable boundary layer observed with fibre-optic distributed temperature sensing. Boundary- Layer Meterology. 2014:online first. doi:10.1007/s10546-014-9972-9.

  11. Achromatic optical diode in fiber optics

    CERN Document Server

    Berent, Michal; Vitanov, Nikolay V

    2013-01-01

    We propose a broadband optical diode, which is composed of one achromatic reciprocal quarter-wave plate and one non-reciprocal quarter-wave plate, both placed between two crossed polarizers. The presented design of achromatic wave plates relies on an adiabatic evolution of the Stokes vector, thus, the scheme is robust and efficient. The possible simple implementation using fiber optics is suggested.

  12. An Efficient Wavelength variation approach for Bend Sensing in Single mode- Multimode-Single mode Optical Fiber Sensors

    OpenAIRE

    Abdul Samee Khan,; Mohd. Sarwar Raeen,

    2012-01-01

    Several aspects of the SMS edge filters have been investigated, including the effect of bending the SMS fiber cores due to fabrication tolerances, polarization dependence, and temperature dependence. These aspects can impair the performance of a wavelength measurement system. There are several approaches which have been proposed and demonstrated to achieve high resolution and accuracy of wavelength measurement. Bending effects due to the splicing process on the spectral characteristics of SMS...

  13. Towards biochips using microstructured optical fiber sensors

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Hoiby, Poul Erik

    2006-01-01

    In this paper we present the first incorporation of a microstructured optical fiber (MOF) into biochip applications. A 16-mm-long piece of MOF is incorporated into an optic-fluidic coupler chip, which is fabricated in PMMA polymer using a CO2 laser. The developed chip configuration allows the continuous control of liquid flow through the MOF and simultaneous optical characterization. While integrated in the chip, the MOF is functionalized towards the capture of a specific single-stranded DNA string by immobilizing a sensing layer on the microstructured internal surfaces of the fiber. The sensing layer contains the DNA string complementary to the target DNA sequence and thus operates through the highly selective DNA hybridization process. Optical detection of the captured DNA was carried out using the evanescent-wave-sensing principle. Owing to the small size of the chip, the presented technique allows for analysis of sample volumes down to 300 nL and the fabrication of miniaturized portable devices.

  14. Multifunctional optical system-on-a-chip for heterogeneous fiber optic sensor networks

    Science.gov (United States)

    Yu, Miao; Pang, Cheng; Gupta, Ashwani

    2015-08-01

    In this article, we review our recent progress on the development of a multifunctional optical system-on-a-chip platform, which can be used for achieving heterogeneous wireless fiber optical sensor networks. A multifunctional optical sensor platform based on the micro-electromechanical systems (MEMS) technology is developed. The key component of the multifunctional optical sensor platform is a MEMS based tunable Fabry-Pérot (FP) filter, which can be used as a phase modulator or a wavelength tuning device in a multifunctional optical sensing system. Mechanics model of the FP filter and optics model of the multifunctional optical sensing system are developed to facilitate the design of the filter. The MEMS FP filter is implemented in a multifunctional optical sensing system including both Fabry-Perot interferometer based sensors and Fiber Bragg grating sensors. The experimental results indicate that this large dynamic range tunable filter can enable high performance heterogeneous optical sensing for many applications.

  15. Sensing via optical interference

    Directory of Open Access Journals (Sweden)

    Ryan C. Bailey

    2005-04-01

    Full Text Available Chemical and biological sensing are problems of tremendous contemporary technological importance in multiple regulatory and human health contexts, including environmental monitoring, water quality assurance, workplace air quality assessment, food quality control, many aspects of biodiagnostics, and, of course, homeland security. Frequently, what is needed, or at least wanted, are sensors that are simultaneously cheap, fast, reliable, selective, sensitive, robust, and easy to use. Unfortunately, these are often conflicting requirements. Over the past few years, however, a number of promising ideas based on optical interference effects have emerged. Each is based to some extent on advances in the design and fabrication of functional materials. Generally, the advances are of two kinds: chemo- and bio-selective recognition and binding, and efficient methods for micropatterning or microstructuring.

  16. Monolithic fiber optic sensor assembly

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Scott

    2015-02-10

    A remote sensor element for spectrographic measurements employs a monolithic assembly of one or two fiber optics to two optical elements separated by a supporting structure to allow the flow of gases or particulates therebetween. In a preferred embodiment, the sensor element components are fused ceramic to resist high temperatures and failure from large temperature changes.

  17. Fiber optic fire detection technology

    International Nuclear Information System (INIS)

    Electrostatic application of paint was, and still is, the most technically feasible method of reducing VOC (volatile organic compounds) emissions, while reducing the cost to apply the coatings. Prior to the use of electrostatics, only two sides of the traditional fire triangle were normally present in the booth, fuel (solvent), and oxygen (air). Now the third leg (the ignition source) was present at virtually all times during the production operation in the form of the electrostatic charge and the resulting energy in the system. The introduction of fiber optics into the field of fire detection was for specific application to the electrostatic painting industry, but specifically, robots used in the application of electrostatic painting in the automotive industry. The use of fiber optics in this hazard provided detection for locations that have been previously prohibited or inaccessible with the traditional fire detection systems. The fiber optic technology that has been adapted to the field of fire detection operates on the principle of transmission of photons through a light guide (optic fiber). When the light guide is subjected to heat, the cladding on the light guide melts away from the core and allows the light (photons) to escape. The controller, which contains the emitter and receiver is set-up to distinguish between partial loss of light and a total loss of light. Glass optical fibers carrying light offer distinct advantages over wires or coaxial cables carrying electricity as a transmission media. The uses of fiber optic detection will be expanded in the near future into such areas as aircraft, cable trays and long conveyor runs because fiber optics can carry more information and deliver it with greater clarity over longer distances with total immunity to all kinds of electrical interference

  18. U-optrode-based fiber optic thermometers

    Science.gov (United States)

    Kalvoda, Ladislav; Aubrecht, Jan; Klepá?ek, Rudolf; Lukášová, Petra

    2011-05-01

    Extremely bent optical fiber (U-optrode) is applicable as a sensing head, signal of which is govern by refractive index and light scattering properties of the surrounding medium. The presented contribution aims to shows that when covered with properly selected polymeric transducers, the reliable and fast thermometers covering different temperature ranges can be constructed suitable for, e.g., measurements in environments with high level of electric or magnetic disturbances. Obviously, the bare optrodes can be also used as sensitive analytic tools for collecting information about thermallyinduced changes of optical and micro-structural properties of polymers.

  19. SPS fiber optic link assessment

    Science.gov (United States)

    Lindsay, T. O.; Nalos, E. J.

    1980-01-01

    Fiber optic technology was selected in the SPS baseline design to transmit a stable phase reference throughout the microwave array. Over a hundred thousand microwave modules are electronically steered by the phase reference signal to form the power beam at the ground receiving station. The initially selected IF distribution frequency of the phase reference signal was set at 980 MHz or a submultiple of it. Fiber optics offers some significant advantages in view of the SPS application. Optical transmission is highly immume to EMI/RFI, which is expected to be severe when considering the low distribution power. In addition, there will be savings in both mass, physical size, and potentially in cost.

  20. Longitudinal strain sensing with photonic crystal fibers and fiber Bragg gratings

    Science.gov (United States)

    Tenderenda, T.; Murawski, M.; Szymanski, M.; Szostkiewicz, L.; Becker, M.; Rothhardt, M.; Bartelt, H.; Mergo, P.; Poturaj, Kl; Makara, M.; Skorupski, K.; Marc, P.; Jaroszewicz, L. R.; Nasilowski, T.

    2014-03-01

    Photonic crystal fibers (PCF), sometimes also referred to as microstructured fibers (MSF), have been a subject of extensive research for over a decade. This is mainly due to the fact that by changing the geometry and distribution of the air holes the fiber properties can be significantly modified and tailored to specific applications. In this paper we present the results of a numerical analysis of the influence of the air-hole distribution on the sensitivity of the propagated modes' effective refractive index to externally applied longitudinal strain. We propose an optimal strain sensitive fiber design, with a number of fibers drawn and experimentally evaluated to confirm the theoretical results. Furthermore as the direct measurement of the effective refractive index change may be complex and challenging in field environment, we propose to use fiber Bragg gratings (FBG) in our sensing set-up. As the Bragg wavelength is a function of the effective refractive index, the external strain changes can be monitored through the Bragg wavelength shift with a simple optical spectrometer. Moreover, since the PCF is also optimized for low-loss splicing with standard single mode fiber, our novel sensor head can be used with standard off-the-shelf components in complex multiplexed sensing arrays, with the measured signal transmitted to and from the sensor head by standard telecom fibers, which significantly reduces costs.

  1. A Novel Design of Grooved Fibers for Fiber-Optic Localized Plasmon Resonance Biosensors

    Directory of Open Access Journals (Sweden)

    Lai-Kwan Chau

    2009-08-01

    Full Text Available Bio-molecular recognition is detected by the unique optical properties of self-assembled gold nanoparticles on the unclad portions of an optical fiber whose surfaces have been modified with a receptor. To enhance the performance of the sensing platform, the sensing element is integrated with a microfluidic chip to reduce sample and reagent volume, to shorten response time and analysis time, as well as to increase sensitivity. The main purpose of the present study is to design grooves on the optical fiber for the FO-LPR microfluidic chip and investigate the effect of the groove geometry on the biochemical binding kinetics through simulations. The optical fiber is designed and termed as U-type or D-type based on the shape of the grooves. The numerical results indicate that the design of the D-type fiber exhibits efficient performance on biochemical binding. The grooves designed on the optical fiber also induce chaotic advection to enhance the mixing in the microchannel. The mixing patterns indicate that D-type grooves enhance the mixing more effectively than U-type grooves. D-type fiber with six grooves is the optimum design according to the numerical results. The experimental results show that the D-type fiber could sustain larger elongation than the U-type fiber. Furthermore, this study successfully demonstrates the feasibility of fabricating the grooved optical fibers by the femtosecond laser, and making a transmission-based FO-LPR probe for chemical sensing. The sensor resolution of the sensor implementing the D-type fiber modified by gold nanoparticles was 4.1 × 10-7 RIU, which is much more sensitive than that of U-type optical fiber (1.8 × 10-3 RIU.

  2. Scintillating optical fibers in mammography

    International Nuclear Information System (INIS)

    Measurements of the MTF and the DQE, on images obtained using a scintillating glass optical fiber system coupled to a mammography film, are displayed in comparison with the measurements obtained by a standard mammography cassette using the same film and the same X-ray dose. The final results are favourable to the scintillating fibers. The use of a CCD read-out in the place of the mammography film is discussed. (orig.)

  3. Optical fiber based radial polarizer

    Science.gov (United States)

    Elbaz, David; Buhbut, Sophia; Kupfer, Benjamin Zeev; Zaban, Arie; Zalevsky, Zeev

    2012-05-01

    In this paper we present a new type of optical fiber aiming to radially polarize the electrical field. This special device is composed of a tapered fiber having a classical core while on top of its external surface, radially oriented nanorods are disposed. The tails of the propagated wave are interacting with those radially oriented nanorods. This interaction performs the polarization of the propagated mode into a radial polarization.

  4. A fiber-optic current sensor for aerospace applications

    International Nuclear Information System (INIS)

    A robust, accurate, broad-band, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low and high voltage 60 Hz terrestrial power systems and in 400 Hz aircraft systems. It is intrinsically EMI immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a novel fiber-optic temperature sensor embedded in the sensing head. This paper reports on the technology contained in the sensor and also relates the results of precision tests conducted at various temperatures within the wide operating range. It also shows the results of early EMI tests

  5. Fiber optic switch concept with analog micromirror device

    Science.gov (United States)

    Lausch, Christine; Goering, Rolf; Wippermann, Frank

    2003-01-01

    A novelle concept for miniaturized multimode fiber optical switches is presented, which can be applied for the whole spectrum of fiber core diameter and numerical aperture. It is particularly useful for large core high numerical aperture fibers used for applications in illumination systems, sensing and optical spectrometers. Because of relaxed positioning tolerances - compared to singlemode setups - most existing solutions are based on moving fibers or fiber collimators leading to devices with excellent optical parameters. Due to the mechanical properties of the fibers it is difficult to use these switching principles for fibers with large diameter. The system we present is based on fixed fibers, each having a collimating lens. A following imaging system projects the incoming optical beam to a tilting high-reflectivity micromirror placed in the focal plane. The reflected beam travels back through the imaging system targeting an output fiber which is addressed by the angle position of the mirror. Due to the folded optics design both input and output channels are located on the same side of the device. Special emphasis was taken on the chromatic dispersion behaviour of the setup leading to a broad spectral range. We present the optical and mechanical design considerations and experimental results obtained with first realized prototypes of 1×4 and 1×8 style switches for 400?m core diameter multimode fibers.

  6. Building polymer fiber optic network

    Science.gov (United States)

    Bienias, P.; Bere?-Pawlik, E.

    2015-09-01

    The paper describes an investigation of transmission in LAN with using polymer optical fiber (POF). There were used two kinds of POF, step index plastic optical fiber (SI-POF) and graded index plastic optical fiber (GI-POF). Furthermore, the paper include a comparison between SI-POF and GI-POF and possibilities of using them. For the project's needs, new type of couplers has been designed and built, optimization has been performed to obtain the best parameters for designed couplers. Additionally, the coupler has been built from the same material, which GI-POF - PMMA is made of. Moreover, CWDM (Coarse Wavelength Division Multiplexing) transmissions is investigated to improve the network capacity.

  7. Integrated optics for fiber gyro's

    Science.gov (United States)

    Goss, W.; Goldstein, R.

    1983-01-01

    Expected advantages of incorporating integrated optical waveguide components into fiber gyroscopes are summarized. The structural-simplicity benefits which can be achieved through the use of solid-state lasers, and integrated and fiber optics are examined; angular rate noise and random walk drift for the current technology in the 0.84-micron wavelength region are reported as 0.00001 deg/sec and 0.0002 deg/hr to the 1/2, respectively. The state-of-the-art in the pertinent materials research is reviewed; lithium niobate, suggested to be used as a waveguide substrate material, is noted to have a complex chemistry that is not yet fully understood. However, most of the optical and electrooptical components of a fiber gyro are conceptually understood and have been demonstrated.

  8. Handbook of fiber optics theory and applications

    CERN Document Server

    Yeh, Chai

    2013-01-01

    Dr. Yeh supplies a firm theoretical foundation in such topics as propagation of light through fibers, fiber fabrication, loss mechanisms, and dispersion properties. He then expands from this into such practical areas as fiber splicing, measuring loss in fibers, fiber-based communications networks, remote fiber sensors, and integrated optics. Whether involved in fiber optics research, design, or practical implementation of systems, this handbook will be extremely useful.Key Features* Here is a comprehensive, ""one-stop"" reference with state-of-the-art information on fiber optics Included is da

  9. Feasibility of soil moisture monitoring with heated fiber optics :

    OpenAIRE

    Sayde, C.; Gregory, C.; Gil-Rodriguez, M.; Tufillaro, N.; Tyler, S; van de Giesen, N.C.; English, M.; Cuenca, R.; Selker, J.S.

    2010-01-01

    Accurate methods are needed to measure changing soil water content from meter to kilometer scales. Laboratory results demonstrate the feasibility of the heat pulse method implemented with fiber optic temperature sensing to obtain accurate distributed measurements of soil water content. A fiber optic cable with an electrically conductive armoring was buried in variably saturated sand and heated via electrical resistance to create thermal pulses monitored by observing the distributed Raman back...

  10. Fiber optics principles and practices

    CERN Document Server

    Al-Azzawi, Abdul

    2007-01-01

    Since the invention of the laser, our fascination with the photon has led to one of the most dynamic and rapidly growing fields of technology. New advances in fiber optic devices, components, and materials make it more important than ever to stay current. Comprising chapters drawn from the author's highly anticipated book Photonics: Principles and Practices, Fiber Optics: Principles and Practices offers a detailed and focused treatment for anyone in need of authoritative information on this critical area underlying photonics.Using a consistent approach, the author leads you step-by-step throug

  11. Fiber optic interferometer with digital heterodyne detection using lithiumniobate devices

    International Nuclear Information System (INIS)

    Fiber optic interferometers with single mode fibers provide high sensitivity for sensing e.g. temperature, sound, electric and magnetic fields. The inclusion of integrated optic components into the interferometer implements important functions such as splitting, recombining, phase compensation, polarization control in a compact way. Above all, integrated optic devices allow efficient heterodyne detection schemes with a linear conversion of the sensor phase ? and the sensor transmission H into corresponding electrical signals. electro-optic LiNbO3 devices are particularly attractive for these purposes. Here, the authors report on fiber optic Michelson and Mach-Zehnder interferometers which are built-up with polarization maintaining fibers and integrated optic LiNbO3 devices. A digital heterodyne detection with a high dynamic range (up to 60 dB) is accomplished by a proper digital phase modulation. A basic configuration is depicted

  12. Subwavelength and nanometer diameter optical fibers

    CERN Document Server

    Tong, Limin

    2011-01-01

    Subwavelength and Nanometer Diameter Optical Fibers provides a comprehensive and up-to-date coverage of research on nanoscale optical fibers including the basic physics and engineering aspects of the fabrication, properties and applications. The book discusses optical micro/nanofibers that represent a perfect fusion of optical fibers and nanotechnology on subwavelength scale and covers a broad range of topics in modern optical engineering, photonics and nanotechnology spanning from fiber optics, near-field optics, nonlinear optics, atom optics to nanofabrication and microphotonic components/de

  13. Drift reduction in an optical heterodyne fiber gyro.

    Science.gov (United States)

    Hotate, K; Samukawa, S

    1990-03-20

    An optical heterodyne fiber gyro, which we recently proposed, is improved to reduce the zero-point drift. A reference interferometer is introduced in the improved configuration beside the sensing interferometer to obtain the Sagnac phase shift, which monitors the drift caused in the optical system. Experimental results demonstrate successful reduction of the drift. PMID:20563004

  14. Development and Application of Fiber-Optic Sensors in Environmental and Life Sciences

    DEFF Research Database (Denmark)

    Rickelt, Lars Fledelius

    2015-01-01

    The light guiding properties of optical fibers are the fundament for fiber-optic sensors. The composition of the fiber materials as well as the fabrication methods for both glass optical fibers and plastic optical fibers (POF) are useful knowledge for improvements of the sensor design. A majority of sensing materials includes imbedded luminescent dyes and all O2 fiber-optic sensors are based on O2 quenching of a luminophore. The mechanisms of luminescence and O2 quenching are described. A new pr...

  15. Fiber-Optic Continuous Liquid Sensor for Cryogenic Propellant Gauging

    Science.gov (United States)

    Xu. Wei

    2010-01-01

    An innovative fiber-optic sensor has been developed for low-thrust-level settled mass gauging with measurement uncertainty optical fiber to measure liquid level and liquid distribution of cryogenic propellants. Every point of the sensing fiber is a point sensor that not only distinguishes liquid and vapor, but also measures temperature. This sensor is able to determine the physical location of each point sensor with 1-mm spatial resolution. Acting as a continuous array of numerous liquid/vapor point sensors, the truly distributed optical sensing fiber can be installed in a propellant tank in the same manner as silicon diode point sensor stripes using only a single feedthrough to connect to an optical signal interrogation unit outside the tank. Either water or liquid nitrogen levels can be measured within 1-mm spatial resolution up to a distance of 70 meters from the optical interrogation unit. This liquid-level sensing technique was also compared to the pressure gauge measurement technique in water and liquid nitrogen contained in a vertical copper pipe with a reasonable degree of accuracy. It has been demonstrated that the sensor can measure liquid levels in multiple containers containing water or liquid nitrogen with one signal interrogation unit. The liquid levels measured by the multiple fiber sensors were consistent with those virtually measured by a ruler. The sensing performance of various optical fibers has been measured, and has demonstrated that they can survive after immersion at cryogenic temperatures. The fiber strength in liquid nitrogen has also been measured. Multiple water level tests were also conducted under various actual and theoretical vibration conditions, and demonstrated that the signal-to-noise ratio under these vibration conditions, insofar as it affects measurement accuracy, is manageable and robust enough for a wide variety of spacecraft applications. A simple solution has been developed to absorb optical energy at the termination of the optical sensor, thereby avoiding any feedback to the optical interrogation unit

  16. Feasibility of giant fiber-optic gyroscopes

    OpenAIRE

    Schiller, Stephan

    2013-01-01

    The availability of long-distance, underground fiber-optic links opens a perspective of implementing interferometric fiber-optic gyroscopes embracing very large areas. We discuss the potential sensitivity, some disturbances and approaches to overcome them.

  17. Polymer optical fiber sensors—a review

    International Nuclear Information System (INIS)

    Polymer optical fibers (POFs) have significant advantages for many sensing applications, including high elastic strain limits, high fracture toughness, high flexibility in bending, high sensitivity to strain and potential negative thermo-optic coefficients. The recent emergence of single-mode POFs has enabled high precision, large deformation optical fiber sensors. This article describes recent advances in both multi-mode and single-mode POF based strain and temperature sensors. The mechanical and optical properties of POFs relevant to strain and temperature applications are first summarized. POFs considered include multi-mode POFs, solid core single-mode POFs and microstructured single-mode POFs. Practical methods for applying POF sensors, including connecting and embedding sensors in structural materials, are also described. Recent demonstrations of multi-mode POF sensors in structural applications based on new interrogation methods, including backscattering and time-of-flight measurements, are outlined. The phase–displacement relation of a single-mode POF undergoing large deformation is presented to build a fundamental understanding of the response of single-mode POF sensors. Finally, this article highlights recent single-mode POF based sensors based on polymer fiber Bragg gratings and microstructured POFs. (topical review)

  18. Crack monitoring capability of plastic optical fibers for concrete structures

    Science.gov (United States)

    Zhao, Jinlei; Bao, Tengfei; Chen, Rui

    2015-08-01

    Optical fibers have been widely used in structural health monitoring. Traditional silica fibers are easy to break in field applications due to their brittleness. Thus, silica fibers are proposed to be replaced by plastic optical fibers (POFs) in crack monitoring in this study. Moreover, considering the uncertainty of crack propagation direction in composite materials, the influence of the angles between fibers and cracks on the monitoring capability of plastic optical fibers is studied. A POF sensing device was designed and the relationship between light intensity loss and crack width under different fiber/crack angles was first measured through the device. Then, three-point bend tests were conducted on concrete beams. POFs were glued to the bottom surfaces of the beams and light intensity loss with crack width was measured. Experimental results showed that light intensity loss in plastic optical fibers increased with crack width increase. Therefore, application of plastic optical fibers in crack monitoring is feasible. Moreover, the results also showed that the sensitivity of the POF crack sensor decreased with the increase of angles between fibers and cracks.

  19. Recent Progress in Distributed Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    Xiaoyi Bao

    2012-06-01

    Full Text Available Rayleigh, Brillouin and Raman scatterings in fibers result from the interaction of photons with local material characteristic features like density, temperature and strain. For example an acoustic/mechanical wave generates a dynamic density variation; such a variation may be affected by local temperature, strain, vibration and birefringence. By detecting changes in the amplitude, frequency and phase of light scattered along a fiber, one can realize a distributed fiber sensor for measuring localized temperature, strain, vibration and birefringence over lengths ranging from meters to one hundred kilometers. Such a measurement can be made in the time domain or frequency domain to resolve location information. With coherent detection of the scattered light one can observe changes in birefringence and beat length for fibers and devices. The progress on state of the art technology for sensing performance, in terms of spatial resolution and limitations on sensing length is reviewed. These distributed sensors can be used for disaster prevention in the civil structural monitoring of pipelines, bridges, dams and railroads. A sensor with centimeter spatial resolution and high precision measurement of temperature, strain, vibration and birefringence can find applications in aerospace smart structures, material processing, and the characterization of optical materials and devices.

  20. Applications of fiber optics in physical protection

    International Nuclear Information System (INIS)

    The purpose of this NUREG is to provide technical information useful for the development of fiber-optic communications and intrusion detection subsystems relevant to physical protection. There are major sections on fiber-optic technology and applications. Other topics include fiber-optic system components and systems engineering. This document also contains a glossary, a list of standards and specifications, and a list of fiber-optic equipment vendors

  1. Engineering modes in optical fibers with metamaterial

    DEFF Research Database (Denmark)

    Yan, Min; Mortensen, Asger; Qiu, Min

    2009-01-01

    In this paper, we report a preliminary theoretical study on optical fibers with fine material inclusions whose geometrical inhomogeneity is almost indistinguishable by the operating wavelength.We refer to such fibers as metamaterial optical fibers, which can conceptually be considered as an extension from the previously much publicized microstructured optical fibers. Metamaterials can have optical properties not obtainable in naturally existing materials, including artificial anisotropy as well ...

  2. 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.

  3. Optical fiber coatings for medical applications

    Science.gov (United States)

    Biswas, Dipak R.

    1992-08-01

    Fiber-optic based laser delivery systems are one of the most important applications of optical fibers in the medical industry. Silica optical fibers are becoming a standard vehicle for laser transport into the human body. Two types of silica core fibers with polymer cladding or glass cladding are being considered. Optical fiber coatings play an important role in fiber strength, reliability, and biocompatibility. Three major coatings, such as organic (polymeric), metallic, and inorganic, are commonly used on optical fibers. The polymeric coatings include ultraviolet-cured acrylate, silicone, and polyimide; metallic coatings include aluminum, indium, tin, and gold; inorganic coatings include oxides, carbides, nitrides, and carbon. In the medical industry, polymeric coatings are widely used. Metallic and inorganic coatings on optical fibers also can be considered. This paper highlights the strength, fatigue, and biocompatibility of silica fibers with different coatings.

  4. Nonlinear fiber optics formerly quantum electronics

    CERN Document Server

    Agrawal, Govind

    1995-01-01

    The field of nonlinear fiber optics has grown substantially since the First Edition of Nonlinear Fiber Optics, published in 1989. Like the First Edition, this Second Edition is a comprehensive, tutorial, and up-to-date account of nonlinear optical phenomena in fiber optics. It synthesizes widely scattered research material and presents it in an accessible manner for students and researchers already engaged in or wishing to enter the field of nonlinear fiber optics. Particular attention is paid to the importance of nonlinear effects in the design of optical fiber communication systems. This is

  5. Selective Serial Multi-Antibody Biosensing with TOPAS Microstructured Polymer Optical Fibers

    Directory of Open Access Journals (Sweden)

    Lars H. Pedersen

    2013-03-01

    Full Text Available We have developed a fluorescence-based fiber-optical biosensor, which can selectively detect different antibodies in serial at preselected positions inside a single piece of fiber. The fiber is a microstructured polymer optical fiber fabricated from TOPAS cyclic olefin copolymer, which allows for UV activation of localized sensor layers inside the holes of the fiber. Serial fluorescence-based selective sensing of Cy3-labelled ?-streptavidin and Cy5-labelled ?-CRP antibodies is demonstrated.

  6. Selective Serial Multi-Antibody Biosensing with TOPAS Microstructured Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Høiby, Poul E.; Pedersen, Lars H.; Bang, Ole

    2013-01-01

    We have developed a fluorescence-based fiber-optical biosensor, which can selectively detect different antibodies in serial at preselected positions inside a single piece of fiber. The fiber is a microstructured polymer optical fiber fabricated from TOPAS cyclic olefin copolymer, which allows for UV activation of localized sensor layers inside the holes of the fiber. Serial fluorescence-based selective sensing of Cy3-labelled ?-streptavidin and Cy5-labelled ?-CRP antibodies is demonstrated.

  7. A Novel Design of Grooved Fibers for Fiber-Optic Localized Plasmon Resonance Biosensors

    OpenAIRE

    Lai-Kwan Chau; Wan-Yun Li; Wei-Te Wu; Tzu-Chien Chao; Chun-Ping Jen; Ching-Te Huang

    2009-01-01

    Bio-molecular recognition is detected by the unique optical properties of self-assembled gold nanoparticles on the unclad portions of an optical fiber whose surfaces have been modified with a receptor. To enhance the performance of the sensing platform, the sensing element is integrated with a microfluidic chip to reduce sample and reagent volume, to shorten response time and analysis time, as well as to increase sensitivity. The main purpose of the present study is to design grooves on the o...

  8. Career Directions--Fiber Optic Installer

    Science.gov (United States)

    Tech Directions, 2012

    2012-01-01

    Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of light through an optical fiber that is roughly the diameter of a human hair. The light forms an electromagnetic carrier wave that is modulated to carry information. Each optical fiber is capable of carrying an enormous amount of…

  9. Fundamental study on the development of fiber optic sensor for real-time sensing of CaCO3 scale formation in geothermal water.

    Science.gov (United States)

    Okazaki, Takuya; Imai, Kenichiro; Tan, Shin Y; Yong, Yun T; Rahman, Faidz A; Hata, Noriko; Taguchi, Shigeru; Ueda, Akira; Kuramitz, Hideki

    2015-01-01

    This study proposes an optical fiber sensor for calcium carbonate (CaCO3) scale formation in water. The sensor is easily fabricated by removing the cladding of a multimode fiber to expose the core towards the surrounding medium in order to detect refractive index change. A variation of the transmittance response from the high refractive index of CaCO3 which precipitated on the fiber core surface was observed. The proposed setup can be used to analyze the transmittance response over wide range of wavelength using white light as a source and also a spectroscopy detector. The curve of the transmittance percentage over time showed that a fiber core with 200 ?m has higher sensitivity as compared to a fiber core with 400 ?m. The findings from this study showed that the sensor detection region at near infrared (NIR) wavelengths showed better sensitivity than visible light (VIS) wavelengths. Field tests were conducted using natural geothermal water at Matsushiro, Japan in order to verify the performance of the proposed sensor. The optical response was successfully evaluated and the analytical results confirmed the capability of monitoring scale formation in a geothermal water environment. PMID:25765379

  10. A fiber optic sensor with a metal organic framework as a sensing material for trace levels of water in industrial gases.

    Science.gov (United States)

    Ohira, Shin-Ichi; Miki, Yusuke; Matsuzaki, Toru; Nakamura, Nao; Sato, Yu-ki; Hirose, Yasuo; Toda, Kei

    2015-07-30

    Industrial gases such as nitrogen, oxygen, argon, and helium are easily contaminated with water during production, transfer and use, because there is a high volume fraction of water in the atmosphere (approximately 1.2% estimated with the average annual atmospheric temperature and relative humidity). Even trace water (<1 parts per million by volume (ppmv) of H2O, dew point < -76 °C) in the industrial gases can cause quality problems in the process such as production of semiconductors. Therefore, it is important to monitor and to control trace water levels in industrial gases at each supplying step, and especially during their use. In the present study, a fiber optic gas sensor was investigated for monitoring trace water levels in industrial gases. The sensor consists of a film containing a metal organic framework (MOF). MOFs are made of metals coordinated to organic ligands, and have mesoscale pores that adsorb gas molecules. When the MOF, copper benzene-1,3,5-tricarboxylate (Cu-BTC), was used as a sensing material, we investigated the color of Cu-BTC with water adsorption changed both in depth and tone. Cu-BTC crystals appeared deep blue in dry gases, and then changed to light blue in wet gases. An optical gas sensor with the Cu-BTC film was developed using a light emitting diode as the light source and a photodiode as the light intensity detector. The sensor showed a reversible response to trace water, did not require heating to remove the adsorbed water molecules. The sample gas flow rate did not affect the sensitivity. The obtained limit of detection was 40 parts per billion by volume (ppbv). The response time for sample gas containing 2.5 ppmvH2O was 23 s. The standard deviation obtained for daily analysis of 1.0 ppmvH2O standard gas over 20 days was 9%. Furthermore, the type of industrial gas did not affect the sensitivity. These properties mean the sensor will be applicable to trace water detection in various industrial gases. PMID:26320652

  11. Interferometric fiber-optic bending / nano-displacement sensor using plastic dual-core fiber

    CERN Document Server

    Qu, H; Skorobogatiy, M

    2014-01-01

    We demonstrate an interferometric fiber-optic bending/micro-displacement sensor based on a plastic dual-core fiber with one end coated with a silver mirror. The two fiber cores are first excited with the same laser beam, the light in each core is then back-reflected at the mirror-coated fiber-end, and, finally, the light from the two cores is made to interfere at the coupling end. Bending of the fiber leads to shifting interference fringes that can be interrogated with a slit and a single photodetector. We find experimentally that the resolution of our bending sensor is ~3x10-4 m-1 for sensing of bending curvature, as well as ~70 nm for sensing of displacement of the fiber tip. We demonstrate operation of our sensor using two examples. One is weighting of the individual micro-crystals of salt, while the other one is monitoring dynamics of isopropanol evaporation.

  12. Optical fiber coatings for biomedical applications

    Science.gov (United States)

    Biswas, Dipak R.

    1992-07-01

    Silica optical fibers commonly are used for diagnostic, endoscopic, and surgical applications in medical industries. Optical fiber coatings play an important role in fiber strength, reliability, and biocompatibility. Three major coatings are commonly used on optical fibers: (1) polymeric coatings, such as UV-cured acrylate, silicone, and polyimide; (2) metallic coatings such as aluminum, indium, tin, and gold; and (3) inorganic coatings such as oxides, carbides, nitrides, and carbon. In the medical industry, polymeric coatings are used widely. Metallic and inorganic coatings on optical fibers can also be used. I describe the strength, fatigue, and biocompatibility of silica fibers with different coatings.

  13. Fabrication Quality Analysis of a Fiber Optic Refractive Index Sensor Created by CO2 Laser Machining

    OpenAIRE

    Wei-Te Wu; Bo-Kuan Yeh; Jaw-Luen Tang; Chien-Hsing Chen

    2013-01-01

    This study investigates the CO2 laser-stripped partial cladding of silica-based optic fibers with a core diameter of 400 ?m, which enables them to sense the refractive index of the surrounding environment. However, inappropriate treatments during the machining process can generate a number of defects in the optic fiber sensors. Therefore, the quality of optic fiber sensors fabricated using CO2 laser machining must be analyzed. The results show that analysis of the fiber core size after machin...

  14. Temperature-independent polymer optical fiber evanescent wave sensor.

    Science.gov (United States)

    Zhong, Nianbing; Liao, Qiang; Zhu, Xun; Zhao, Mingfu; Huang, Yun; Chen, Rong

    2015-01-01

    Although the numerous advantages of polymer optical fibers have been exploited in the fields of sensors and telecommunications, such fibers still experience a critical problem: the temperature dependency. Therefore, we explored the temperature-independent operation of a polymer fiber-optic evanescent wave sensor immersed in distilled water. We investigated variations in the surface morphology, deformation trajectory, refractive index, and weight of the fiber-sensing region with varying water temperature. We also examined the spectral transmission and transmitted light intensity of fibers subjected to a heating-cooling treatment. We observed that the light-transmission modes and sensitivity of the sensor were affected by changes in the surface morphology, diameter, and refractive index of the sensing region caused by changes in temperature. The transmitted light intensity of the sensor was maintained at a constant level after five cycles of the heating-cooling treatment, after which the fibers exhibited a smooth surface, low refractive index, and large fiber diameter. Consequently, we utilized the heating-cooling-treated fiber to realize a temperature-independent, U-shaped polymer fiber-optic evanescent wave sensor. The temperature independence was evaluated using glucose solutions in the range of 10 to 70?°C. The fabricated sensor showed significant temperature independence and high degree of consistency in measuring solutions. PMID:26112908

  15. Design and optimization of microstructured optical fiber sensors

    Science.gov (United States)

    Jewart, Charles Milford

    2011-12-01

    The integration of sensor networks into large civil and mechanical structures is becoming an important engineering practice to ensure the structural health of important infrastructure and power generation facilities. The temperature, pressure, and internal stress distribution within the structures are key parameters to monitor the structural health of a system. Optical fiber sensors are one of the most common sensing elements used in the structural health monitoring due to their compact size, low cost, electrical immunity, and multiplexing ability. In this dissertation, the design and optimization of air-hole microstructured optical fibers for use as application specific sensors is presented. Air hole matrices are used to design fiber cores with a large birefringence; while air hole arrays within the fiber cladding are studied and optimized to engineer unique geometries that can give desired sensitivity and directionality of the fiber sensors. A pure silica core microstructured photonic crystal fiber was designed for hydrostatic pressure sensing. The impact of the surrounding air-holes to the propagation mode profiles and indices were studied and improved. To improve directionality and sensitivity of fiber sensors, air holes in the fiber cladding were implemented and optimized in the design of the fiber. Finite element analysis simulations were performed to elicit the correlation between air-hole configuration and the fiber sensor's performance and impact of the fiber's opto-mechanic properties. To measure pressure and stress at high temperature, an ultrafast laser was used to inscribe type II gratings in two-hole microstructured optical fibers and suspended core fibers. The fiber Bragg grating resonance wavelength shift and peak splitting were studied as a function of external pressure, bending, and lateral compression. Fiber sensors in two-hole fibers show stable and reproducible operation above 800°C. Fiber grating sensor in suspended core fibers exhibits high directionality to transverse stress, and insensitivity to bending. All experimental results are in good agreement with the simulations. This works demonstrates that ingenious design and engineering of air hole matrices in optical fiber's cladding and core can lead to multi-functional and multiplexable fiber sensors that were previously unattainable using traditional solid-core solid cladding fiber.

  16. An Integrated Photoluminescence Sensing Platform Using a Single-Multi-Mode Fiber Coupler-Based Probe

    OpenAIRE

    Feng Long; Anna Zhu; Hanchang Shi

    2014-01-01

    We demonstrate an integrated fiber optic photoluminescence sensing platform using a novel single-multi-mode fiber coupler (SMFC)-based probe with high collection efficiency for fluorescence signals. The SMFC, prepared using fused biconical taper technology, not only transmits excitation light, but also collects and transmits fluorescence. The entire system does not use complex optical components and rarely requires optical alignment. The simple structure of the SMFC considerably improves the ...

  17. Novel optical microresonators for sensing applications

    Science.gov (United States)

    Wang, Hanzheng

    Optical microresonators have been proven as an effective means for sensing applications. The high quality (Q) optical whispering gallery modes (WGMs) circulating around the rotationally symmetric structures can interact with the local environment through the evanescent field. The high sensitivity in detection was achieved by the long photon lifetime of the high-Q resonator (thus the long light-environment interaction path). The environmental variation near the resonator surface leads to the effective refractive index change and thus a shift at the resonance wavelength. In this dissertation, we present our recent research on the development of new optical microresonators for sensing applications. Different structures and materials are used to develop optical resonator for broad sensing applications. Specifically, a new coupling method is designed and demonstrated for efficient excitation of microsphere resonators. The new coupler is made by fusion splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. Operating in the reflection mode and providing a robust mechanical support to the microresonator, the integrated structure has been experimentally proven as a convenient probe for sensing applications. Microspheres made of different materials (e.g., PMMA, porous glass, hollow core porous, and glass solid borosilicate glass) were successfully demonstrated for different sensing purposes, including temperature, chemical vapor concentration, and glucose concentration in aqueous solutions. In addition, the alignment free, integrated microresonator structure may also find other applications such as optical filters and microcavity lasers.

  18. Development of pulsed fiber lasers for long-range remote sensing

    Science.gov (United States)

    Di Teodoro, Fabio; Belden, Paul; Ionov, Pavel; Werner, Nicolette; Fathi, Gilda

    2014-03-01

    Pulsed fiber lasers bear great promise as optical transmitters for remote sensors, having tight size, power consumption, and ruggedness constraints. We discuss recently introduced laser architectures and components supporting power scaling of efficient fiber-based laser sources for long-range operation consistent with imaging and/or spectroscopic sensing from high-altitude and space-based platforms.

  19. Quasi-distributed long-gauge fiber optic sensor system.

    Science.gov (United States)

    Linec, Matjaz; Donlagi?, Denis

    2009-07-01

    This paper presents a quasi-distributed, long-gauge, sensor system for measurement optical path length variation. This system can be directly applied to long gauge strain and/or temperature sensing. The proposed sensor system is comprised of sensing fiber, which is divided into the sensor's segments separated by semi reflective mirrors made out of standard optical connectors. Short duration radio-frequency modulated optical bursts are launched into the sensing fiber and phase differences among individual reflected bursts are measured to determine the optical path-length variations among neighboring mirrors. Twenty sensing fiber segments were successfully addressed by a single-signal processor, while relying on standard telecommunication PIN diode, and a Fabry Perot laser diode. The resolution of a fiber-length variation better than 5 microm was demonstrated in practice. Since the long sections of fiber can be employed for constructing individual sensors within the sensor's array, a microstrain resolution can be achieved in practice. The drift of the sensor's system can be predominantly attributed to the temperature sensitivity of the electronic components, which proved to be below 20 microm/ degrees C. The entire system relies on simple and widely-used components that are low-cost. PMID:19582067

  20. Application of active heat pulse method with fiber optic temperature sensing for estimation of wetting bulbs and water distribution in drip emitters.

    OpenAIRE

    Gil Rodríguez, María; Rodríguez Sinobas, Leonor; Benitez Buelga, Javier; Sánchez Calvo, Raúl

    2013-01-01

    Through the use of the Distributed Fiber Optic Temperature Measurement (DFOT) method, it is possible to measure the temperature in small intervals (on the order of centimeters) for long distances (on the order of kilometers) with a high temporal frequency and great accuracy. The heat pulse method consists of applying a known amount of heat to the soil and monitoring the temperature evolution, which is primarily dependent on the soil moisture content. The use of both methods, which is called t...

  1. All-optical devices in polymer optical fiber

    Science.gov (United States)

    Kuzyk, Mark G.; Garvey, Dennis W.; Vigil, Steven R.; Welker, David J.

    1999-07-01

    We report on polymer optical fiber devices for sensors, optical switches/logic, and optical actuators. In this paper, we give a brief overview of polymer fibers, discuss recent all-optical switching results, and describe how an optical sensor and actuator can be built into a single fiber device. Future technologies that are made possible with such optical devices and photomechanical mechanisms are also discussed.

  2. Active Optical Fibers Doped with Ceramic Nanocrystals

    Directory of Open Access Journals (Sweden)

    Jan Mrazek

    2014-01-01

    Full Text Available Erbium-doped active optical fiber was successfully prepared by incorporation of ceramic nanocrystals inside a core of optical fiber. Modified chemical vapor deposition was combined with solution-doping approach to preparing preform. Instead of inorganic salts erbium-doped yttrium-aluminium garnet nanocrystals were used in the solution-doping process. Prepared preform was drawn into single-mode optical fiber with a numerical aperture 0.167. Optical and luminescence properties of the fiber were analyzed. Lasing ability of prepared fiber was proofed in a fiber-ring set-up. Optimal laser properties were achieved for a fiber length of 20~m. The slope efficiency of the fiber-laser was about 15%. Presented method can be simply extended to the deposition of other ceramic nanomaterials.

  3. Use of optical fibers in spectrophotometry

    Science.gov (United States)

    Ramsey, Lawrence W.

    1988-01-01

    The use of single or small numbers of fiber optic fibers in astronomical spectroscopy with the goal of greater spectrophotometric and radial velocity accuracy is discussed. The properties of multimode step index fibers which are most important for this application are outlined, as are laboratory tests of currently available fibers.

  4. Chronology of Fabry-Perot Interferometer Fiber-Optic Sensors and Their Applications: A Review

    OpenAIRE

    Md. Rajibul Islam; Muhammad Mahmood Ali; Man-Hong Lai; Kok-Sing Lim; Harith Ahmad

    2014-01-01

    Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferome...

  5. Utilization of fiber optics in radiation diagnostics

    International Nuclear Information System (INIS)

    Fiber optics can provide a cost effective transmission medium for wide bandwidth radiation diagnostics. Passive systems have been investigated which allow conversion of radiation energy to optical energy with direct coupling to optical fibers. Organic scintillators have been developed which emit at wavelengths near 600 nm. The new scintillators yield a FWHM below 1.5 ns. The scintillator emission band is very broad, leading to the requirement of optical filtering to limit material dispersion in the fiber. Trade-offs involving fiber length, dynamic range, fiber radiation damage, scintillator radiation damage, bandwidth, and spectral filter width are discussed

  6. Real-time In-Flight Strain and Deflection Monitoring with Fiber Optic Sensors

    Science.gov (United States)

    Richards, Lance; Parker, Allen R.; Ko, William L.; Piazza, Anthony

    2008-01-01

    This viewgraph presentation reviews Dryden's efforts to develop in-flight monitoring based on Fiber Optics. One of the motivating factors for this development was the breakup of the Helios aircraft. On Ikhana the use of fiber optics for wing shape sensing is being developed. They are being used to flight validate fiber optic sensor measurements and real-time wing shape sensing predictions on NASA's Ikhana vehicle; validate fiber optic mathematical models and design tools; Assess technical viability and, if applicable, develop methodology and approach to incorporate wing shape measurements within the vehicle flight control system, and develop and flight validate advanced approaches to perform active wing shape control.

  7. Comparison of optical fiber Bragg grating hydrogen sensors with Pd-based thin films and sol–gel WO3 coatings

    International Nuclear Information System (INIS)

    Pd-based thin films and sol–gel WO3 coatings are two kinds of hydrogen sensitive elements used in hydrogen concentration sensing and detection. Optical fiber hydrogen sensors are very promising solutions for flammable hydrogen detection, when the sensitive materials are integrated with optical fiber sensors. This paper reviews the sensing performance of optical fiber hydrogen sensors with these two sensitive materials, which are developed at the National Engineering Laboratory for Optical Fiber Sensing Technologies in Wuhan University of Technology. (paper)

  8. 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

  9. Fiber-optically sensorized composite wing

    Science.gov (United States)

    Costa, Joannes M.; Black, Richard J.; Moslehi, Behzad; Oblea, Levy; Patel, Rona; Sotoudeh, Vahid; Abouzeida, Essam; Quinones, Vladimir; Gowayed, Yasser; Soobramaney, Paul; Flowers, George

    2014-04-01

    Electromagnetic interference (EMI) immune and light-weight, fiber-optic sensor based Structural Health Monitoring (SHM) will find increasing application in aerospace structures ranging from aircraft wings to jet engine vanes. Intelligent Fiber Optic Systems Corporation (IFOS) has been developing multi-functional fiber Bragg grating (FBG) sensor systems including parallel processing FBG interrogators combined with advanced signal processing for SHM, structural state sensing and load monitoring applications. This paper reports work with Auburn University on embedding and testing FBG sensor arrays in a quarter scale model of a T38 composite wing. The wing was designed and manufactured using fabric reinforced polymer matrix composites. FBG sensors were embedded under the top layer of the composite. Their positions were chosen based on strain maps determined by finite element analysis. Static and dynamic testing confirmed expected response from the FBGs. The demonstrated technology has the potential to be further developed into an autonomous onboard system to perform load monitoring, SHM and Non-Destructive Evaluation (NDE) of composite aerospace structures (wings and rotorcraft blades). This platform technology could also be applied to flight testing of morphing and aero-elastic control surfaces.

  10. Electron spin manipulation and readout through an optical fiber

    OpenAIRE

    I. V. Fedotov; L. V. Doronina-Amitonova; Voronin, A. A.; Levchenko, A. O.; S. A. Zibrov; Sidorov-Biryukov, D. A.; Fedotov, A. B.; Velichansky, V. L.; A. M. Zheltikov

    2014-01-01

    The electron spin of nitrogen--vacancy (NV) centers in diamond offers a solid-state quantum bit and enables high-precision magnetic-field sensing on the nanoscale. Implementation of these approaches in a fiber format would offer unique opportunities for a broad range of technologies ranging from quantum information to neuroscience and bioimaging. Here, we demonstrate an ultracompact fiber-optic probe where a diamond microcrystal with a well-defined orientation of spin quantization NV axes is ...

  11. Nanostructured Substrates for Optical Sensing

    OpenAIRE

    Kemling, Jonathan W; Qavi, Abraham J.; Bailey, Ryan C.; Suslick, Kenneth S

    2011-01-01

    Sensors that change color have the advantages of versatility, ease of use, high sensitivity, and low cost. The recent development of optically based chemical sensing platforms has increasingly employed substrates manufactured with advanced processing or fabrication techniques to provide precise control over shape and morphology of the sensor micro- and nano-structure. New sensors have resulted with improved capabilities for a number of sensing applications, including the detection of biomolec...

  12. Quantitative broadband chemical sensing in air-suspended solid-core fibers

    OpenAIRE

    Euser, T. G.; Chen, J. S. Y.; Farrer, N. J.; Scharrer, M.; Sadler, P. J.; Russell, P. St. J.

    2007-01-01

    We demonstrate a quantitative broadband fiber sensor, based on evanescent field sensing in the cladding holes of an air-suspended solid-core photonic crystal fiber. We discuss the fabrication process, together with the structural- and optical characterization of a range of different fibers. Measured mode profiles are in good agreement with finite element method calculations made without free parameters. The fraction of the light in the hollow cladding can be tuned via the co...

  13. Axial strain and temperature sensing characteristics of the single-coreless-single mode fiber structure-based fiber ring laser

    Science.gov (United States)

    Liu, Zhi-bo; Yin, Bin; Liang, Xiao; Bai, Yunlong; Tan, Zhongwei; Liu, Shuo; Li, Yang; Liu, Yan; Jian, Shuisheng

    2014-06-01

    This paper experimentally demonstrated a singlemode-coreless-singlemode (SCS) fiber structure-based fiber ring cavity laser for strain and temperature measurement. The basis of the sensing system is the multimodal interference occurs in coreless fiber, and the transmission spectrum is sensitive to the ambient perturbation. In this sensing system, the SCS fiber structure not only acts as the sensing head of the sensor but also the band-pass filter of the ring laser. Blue shift with strain sensitivity of ˜ -2 pm/?? ranging from 0 to 730 ?? and red shift with temperature sensitivity of ˜ 11 pm/°C ranging from 5 to 75 °C have been achieved. Experimental results also show the proposal has great potential in using long-distance operation. The fiber ring laser sensing system has a optical signal to noise ratio (OSNR) more than 50 and 3 dB bandwidth less than 0.05 nm. The result shows that the coreless fiber has no improvement of the temperature and axial strain sensitivity. However, compared to the common singlemode-multimode-singlemode fiber structure sensors, the laser sensing system has the additional advantages of high OSNR, high intensity and narrow 3 dB bandwidth, and thus improves the accuracy.

  14. A Highly Sensitive Fiber Optic Sensor Based on Two-Core Fiber for Refractive Index Measurement

    OpenAIRE

    Daniel Alberto May-Arrioja; Miguel Torres-Cisneros; José Javier Sánchez-Mondragón; José Rafael Guzmán-Sepúlveda; Rafael Guzmán-Cabrera

    2013-01-01

    A simple and compact fiber optic sensor based on a two-core fiber is demonstrated for high-performance measurements of refractive indices (RI) of liquids. In order to demonstrate the suitability of the proposed sensor to perform high-sensitivity sensing in a variety of applications, the sensor has been used to measure the RI of binary liquid mixtures. Such measurements can accurately determine the salinity of salt water solutions, and detect the water content of adulterated alcoholic beverage...

  15. Fiber optic probes for laser light scattering: Ground based evaluation for micgrogravity flight experimentation. Integrated coherent imaging fiber optic systems for laser light scattering and other applications

    Science.gov (United States)

    Dhadwal, Harbans Singh

    1994-01-01

    The research work presented in this report has established a new class of backscatter fiber optics probes for remote dynamic light scattering capability over a range of scattering angles from 94 degrees to 175 degrees. The fiber optic probes provide remote access to scattering systems, and can be utilized in either a noninvasive or invasive configuration. The fiber optics create an interference free data channel to inaccessible and harsh environments. Results from several studies of concentrated suspension, microemulsions, and protein systems are presented. The second part of the report describes the development of a new technology of wavefront processing within the optical fiber, that is, integrated fiber optics. Results have been very encouraging and the technology promises to have significant impact on the development of fiber optic sensors in a variety of fields ranging from environmental monitoring to optical recording, from biomedical sensing to photolithography.

  16. The Effects of High Temperature and Nuclear Radiation on the Optical Transmission of Silica Optical Fibers

    Science.gov (United States)

    Hawn, David P.

    Distributed measurements made with fiber optic instrumentation have the potential to revolutionize data collection for facility monitoring and process control in industrial environments. Dozens of sensors etched into a single optical fiber can be used to instrument equipment and structures so that dozens of spatially distributed temperature measurements, for example, can be made quickly using one optical fiber. Optically based sensors are commercially available to measure temperature, strain, and other physical quantities that can be related to strain, such as pressure and acceleration. Other commercially available technology eliminates the need to etch discrete sensors into an optical fiber and allows temperature measurements to be made along the length of an ordinary silica fiber. Distributed sensing with optical instrumentation is commonly used in the petroleum industry to measure the temperature and pressure profiles in down hole applications. The U.S. Department of Energy is interested in extending the distributed sensing capabilities of optical instrumentation to high temperature reactor radiation environments. For this technology extension to be possible, the survivability of silica optical fibers needed to be determined in this environment. In this work the optical attenuation added to silica optical fiber exposed simultaneously to reactor radiation and temperatures to 1000°C was experimentally determined. Optical transmission measurements were made in-situ from 400nm-2300nm. For easy visualization, all of the results generated in this work were processed into movies that are available publicly [1]. In this investigation, silica optical fibers were shown to survive optically and mechanically in a reactor radiation environment to 1000°C. For the combined high temperature reactor irradiation experiments completed in this investigation, the maximum attenuation increase in the low-OH optical fibers was around 0.5db/m at 1550nm and 0.6dB/m at 1300nm. The radiation induced optical attenuation primarily affected wavelengths less than 1000nm and this attenuation cannot be avoided in silica. Thermal effects dominated the increase in attenuation at wavelengths above 1000nm and it may be possible to mitigate these effects. Fortuitously, commercial optical instrumentation typically utilizes wavelengths centered around 1300nm and 1550nm where the radiation induced attenuation was minimal. The maximum continuous use temperature of silica optical fiber may be limited to 900°C with intermittent use to 1000°C. The silica optical fibers tested in this project are inexpensive and commercially available. Optical sensors were not tested in this project and development and testing of radiation hard optical sensors is recommended as future work.

  17. Hardened fiber optic links for nuclear industry

    International Nuclear Information System (INIS)

    Typical behaviour of fiber optic exposed to a steady state gamma ray irradiation show the improvement of induced loss value by appropriate photo bleaching in pure silica core fibers. Taking care of the environment in industrial nuclear process, two fiber optic transmission links have been designed. To improve performances of servomanipulators used in nuclear fuel reprocessing plants an experimental three fiber data link was made with tested hardened components and its functionality is anticipated up to 105 Gy

  18. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

    In this thesis differenct optical fiber gratings are used for sensor purposes. If a fiber with a core concentricity error (CCE) is used, a directional dependent bend sensor can be produced. The CCE direction can be determined by means of diffraction. This makes it possible to produce long-period gratings in a fiber with a CCE direction parallel or perpendicular to the writing direction. The maximal bending sensitivity is independent on the writing direction, but the detailed bending response is different in the two cases. A temperature and strain sensor, based on a long-period grating and two sampled gratings, was produced and investigated. It is based on the different temperature and strain response of these gratings. Both a transfer matrix method and an overlap calculation is performed to explain the sensor response. Another type of sensor is based on tuning and modulation of a laser wavelength. It is shown that it is possible to tune and modulate a DFB fiber laser with both strain from a piezoelectric transducer and by temperature through resistive heating of a methal film. Both a chemical deposited silver layer and an electron-beam evaporation technique has been investigated, to find the most reproducible method. Such a laser can be applied for gas monitoring and it can be stabilized by locking it to an absorption line. The locked laser has a stability of ~2 MHz, which makes it suitable as a wavelength standard in the 1.5 um telecommunication band.

  19. Nanosecond laser micropatterning of optical fibers

    Science.gov (United States)

    Nespereira, Marta; Silva, Catarina; Coelho, João M. P.; Rebordão, José M.

    2011-05-01

    Towards the development of new optical fiber sensors it was studied the application of nanosecond infrared laser radiation in the micropatterning of optical fibers. Nd:YAG laser pulses were focused on silica fibers by an apparatus projected to position the fiber regarding the laser beam and analyze the interaction. Experiments allowed determining the conditions to vaporize the required amount of material. Holes with few microns and depths higher than 10 microns were accomplished with multiple shots and advancing the fiber regarding the beam's focus. The results analysis demonstrated the possibility of obtaining patterns and the technique potential in the development of fiber sensors.

  20. Fiber Optics Physics and Technology

    CERN Document Server

    Mitschke, Fedor

    2010-01-01

    Telephone, telefax, email and internet -- the key ingredient of the inner workings is the conduit: the line which is designed to carry massive amounts of data at breakneck speed. In their data-carrying capacity optical fiber lines beat other technologies (copper cable, microwave beacons, satellite links) hands down, at least in the long haul. This book tells you all you want to know about optical fibers: Their structure, their light-guiding mechanism, their material and manufacture, their use. Several effects tend to degrade the signal as it travels down the fiber: they are spelled out in detail. Nonlinear processes are given due consideration for a twofold reason: On the one hand they are fundamentally different from the more familiar processes in electrical cable. On the other hand, they form the basis of particularly interesting and innovative applications, provided they are understood well enough. A case in point is the use of so-called solitons, i.e. special pulses of light which have the wonderful prope...

  1. Optical carrier-based microwave interferometers for sensing application

    Science.gov (United States)

    Huang, Jie; Lan, Xinwei; Wang, Hanzheng; Yuan, Lei; Xiao, Hai

    2014-06-01

    Optical fiber interferometers (OFIs) have been extensively utilized for precise measurements of various physical/chemical quantities (e.g., temperature, strain, pressure, rotation, refractive index, etc.). However, the random change of polarization states along the optical fibers and the strong dependence on the materials and geometries of the optical waveguides are problematic for acquiring high quality interference signal. Meanwhile, difficulty in multiplexing has always been a bottleneck on the application scopes of OFIs. Here, we present a sensing concept of optical carrier based microwave interferometry (OCMI) by reading optical interferometric sensors in microwave domain. It combines the advantages from both optics and microwave. The low oscillation frequency of the microwave can hardly distinguish the optical differences from both modal and polarization dispersion making it insensitive to the optical waveguides/materials. The phase information of the microwave can be unambiguitly resolved so that it has potential in fully distributed sensing. The OCMI concept has been implemented in different types of interferometers (i.e., Michelson, Mach-Zehnder, Fabry-Perot) among different optical waveguides (i.e., singlemode, multimode, and sapphire fibers) with excellent signal-to-noise ratio (SNR) and low polarization dependence. A spatially continuous distributed strain sensing has been demonstrated.

  2. Analog fiber optic transmission link

    International Nuclear Information System (INIS)

    An analog fiber optic transmission link (FOTL) has been designed for relaying signals from equipment held at high voltage potentials to equipment at ground potential. The need for a fiber link arises from the requirements of low energy, light ion experiments conducted at the Triangle Universities Nuclear Laboratory. In these experiments, ions are accelerated and transported to a high voltage scattering chamber and the FOTL is used to transmit signals from the scattering chamber to remote data acquisition systems. The performance of the link is mainly driven by the stringent requirements needed for successful transmission of analog pulses from radiation detectors located in the scattering chamber. The FOTL consists of a transmitter, receiver, and baseline restorer that are capable of transmitting radiation detector pulses without pulse height distortion, thus allowing high resolution energy measurements. The FOTL is also suitable for use with a wide variety of other analog signal types

  3. Fiber-optical accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole; Andresen, Søren; Nielsen, Finn Kryger; Jacobsen, Torben; Rose, Bjarke; Herholdt-Rasmussen, Nicolai

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer.

  4. The soliton transmissions in optical fibers

    OpenAIRE

    Leos Bohac

    2010-01-01

    The objective of this paper is to familiarize readers with the basic analytical propagation model of short optical pulses in optical fiber. Based on this model simulation of propagation of the special type of pulse, called a soliton, will be carried out. A soliton transmission is especially attractive in the fiber optic telecommunication systems as it does not change a pulses shape during propagating right-down the fiber link to the receiver. The model of very short pulse propagation is based...

  5. Nanoparticle-doped radioluminescent silica optical fibers.

    Czech Academy of Sciences Publication Activity Database

    Mrázek, Jan; Nikl, Martin; Kašík, Ivan; Podrazký, Ond?ej; Aubrecht, Ivo; Beitlerová, Alena

    Vol. 9228. Bellingham : SPIE, 2014 - (Dorosz, J.; Romaniuk, R.), s. 922805 ISBN 978-1-62841-275-8. ISSN 0277-786X. [15th Symposia on Optical Fibers and their Applications. Bialystok (PL), 29.01.2014-01.02.2014] Institutional support: RVO:67985882 ; RVO:68378271 Keywords : Fiber optic sensors * Nanoparticle s * Optical fibers Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering; CF - Physical ; Theoretical Chemistry (FZU-D)

  6. Thermal Strain Analysis of Optic Fiber Sensors

    OpenAIRE

    Chih-Ying Huang; Shiuh-Chuan Her

    2013-01-01

    An optical fiber sensor surface bonded onto a host structure and subjected to a temperature change is analytically studied in this work. The analysis is developed in order to assess the thermal behavior of an optical fiber sensor designed for measuring the strain in the host structure. For a surface bonded optical fiber sensor, the measuring sensitivity is strongly dependent on the bonding characteristics which include the protective coating, adhesive layer and the bonding length. Thermal str...

  7. Interferometric microstructured polymer optical fiber ultrasound sensor for optoacoustic endoscopic imaging in biomedical applications

    DEFF Research Database (Denmark)

    Gallego, Daniel; Sáez-Rodríguez, David

    2014-01-01

    We report a characterization of the acoustic sensitivity of microstructured polymer optical fiber interferometric sensors at ultrasonic frequencies from 100kHz to 10MHz. The use of wide-band ultrasonic fiber optic sensors in biomedical ultrasonic and optoacoustic applications is an open alternative to conventional piezoelectric transducers. These kind of sensors, made of biocompatible polymers, are good candidates for the sensing element in an optoacoustic endoscope because of its high sensitivity, its shape and its non-brittle and non-electric nature. The acoustic sensitivity of the intrinsic fiber optic interferometric sensors depends strongly of the material which is composed of. In this work we compare experimentally the intrinsic ultrasonic sensitivities of a PMMA mPOF with other three optical fibers: a singlemode silica optical fiber, a single-mode polymer optical fiber and a multimode graded-index perfluorinated polymer optical fiber. © 2014 SPIE.

  8. Enhancing Optical Communications with Brand New Fibers

    DEFF Research Database (Denmark)

    Morioka, Toshio; Awaji, Yoshinari

    2012-01-01

    Optical fibers have often been considered to offer effectively infinite capacity to support the rapid traffic growth essential to our information society. However, as demand has grown and technology has developed, we have begun to realize that there is a fundamental limit to fiber capacity of ~ 100 Tb/s per fiber for systems based on conventional single-core single-mode optical fiber as the transmission medium. This limit arises from the interplay of a number of factors including the Shannon limit, optical fiber nonlinearities, the fiber fuse effect, as well as optical amplifier bandwidth. This article reviews the most recent research efforts around the globe launched over the past few years with a view to overcome these limitations and substantially increase capacity by exploring the last degree of freedom available: the spatial domain. Central to this effort has been the development of brand new fibers for space-division multiplexing and mode-division multiplexing.

  9. Engineering metal oxide nanostructures for the fiber optic sensor platform.

    Science.gov (United States)

    Poole, Zsolt L; Ohodnicki, Paul; Chen, Rongzhang; Lin, Yuankun; Chen, Kevin P

    2014-02-10

    This paper presents an effective integration scheme of nanostructured SnO2 with the fiber optic platform for chemical sensing applications based on evanescent optical interactions. By using a triblock copolymer as a structure directing agent as the means of nano-structuring, the refractive index of SnO2 is reduced from >2.0 to 1.46, in accordance with effective medium theory for optimal on-fiber integration. High-temperature stable fiber Bragg gratings inscribed in D-shaped fibers were used to perform real-time characterization of optical absorption and refractive index modulation of metal oxides in response to NH3 from the room temperature to 500 °C. Measurement results reveals that the redox reaction of the nanostructured metal oxides exposed to a reactive gas NH3 induces much stronger changes in optical absorption as opposed to changes in the refractive index. Results presented in this paper provide important guidance for fiber optic chemical sensing designs based on metal oxide nanomaterials. PMID:24663558

  10. Monitoring the Evaporation of Fluids from Fiber-Optic Micro-Cell Cavities

    OpenAIRE

    Borut Preloznik; Vlada Artel; Sukenik, Chaim N.; Denis Donlagic; Avi Zadok; Eyal Preter

    2013-01-01

    Fiber-optic sensors provide remote access, are readily embedded within structures, and can operate in harsh environments. Nevertheless, fiber-optic sensing of liquids has been largely restricted to measurements of refractive index and absorption spectroscopy. The temporal dynamics of fluid evaporation have potential applications in monitoring the quality of water, identification of fuel dilutions, mobile point-of-care diagnostics, climatography and more. In this work, the fiber-optic monitori...

  11. Optical Fiber LSPR Biosensor Prepared by Gold Nanoparticle Assembly on Polyelectrolyte Multilayer

    OpenAIRE

    Yunliang Shao; Shuping Xu; Xianliang Zheng; Ye Wang; Weiqing Xu

    2010-01-01

    This article provides a novel method of constructing an optical fiber localized surface plasmon resonance (LSPR) biosensor. A gold nanoparticle (NP) assembled film as the sensing layer was built on the polyelectrolyte (PE) multilayer modified sidewall of an unclad optical fiber. By using a trilayer PE structure, we obtained a monodisperse gold NP assembled film. The preparation procedure for this LSPR sensor is simple and time saving. The optical fiber LSPR sensor has higher sensitivity and o...

  12. Welding-fume-induced transmission loss in tapered optical fibers

    Science.gov (United States)

    Yi, Ji-Haeng

    2015-09-01

    This paper presents a method for sensing welding fumes in real time. This method is based on the results of nanoparticle-induced optical-fiber loss experiments that show that the losses are determined by the nanoparticle density and the taper waist. The tapered fiber is obtained by applying heat radiated from hot quartz, and monitoring is done in real time. First, the durability of the tapered fiber during the welding process is proven. Then, the loss is categorized by using the sizes of welding fume particles. The sensitivity to welding fumes increases with increasing size of the particles; consequently, the dimension of the taper waist decreases.

  13. Normal And Surface-Enhanced Raman Scattering With Optical Fibers

    Science.gov (United States)

    Myrick, Michael L.; Angel, S. M.

    1990-02-01

    Raman scattering techniques, because of the vibrational information they contain, have numerous applications in the measurement and identification of aqueous pollutants in groundwater, as well as other contaminated waters. However, the extension of Raman techniques using fiber optics to remote sensing of groundwater is not completely straightforward. Single-fiber optrodes provide the greatest signals but also large background levels. Multiple-fiber optrodes offer lower background levels but are not practical over very long distances and are not as sensitive as single-fiber optrodes. The difficulties of obtaining Raman spectra with fiber optics are discussed, and the potential techniques for overcoming the limitations of single-fiber devices are descrivbed. The results of Raman spectral measurements that were made using a dual-fiber optrode in a novel forward-scattering configuration will be presented. The possible extension of these results to surface-enhanced Raman (SER) scattering will be discussed. In addition initial results of SERS performed with optical fibers will be presented, along with a description of future directions for this research.

  14. Development of smart textiles with embedded fiber optic chemical sensors

    Science.gov (United States)

    Khalil, Saif E.; Yuan, Jianming; El-Sherif, Mahmoud A.

    2004-03-01

    Smart textiles are defined as textiles capable of monitoring their own health conditions or structural behavior, as well as sensing external environmental conditions. Smart textiles appear to be a future focus of the textile industry. As technology accelerates, textiles are found to be more useful and practical for potential advanced technologies. The majority of textiles are used in the clothing industry, which set up the idea of inventing smart clothes for various applications. Examples of such applications are medical trauma assessment and medical patients monitoring (heart and respiration rates), and environmental monitoring for public safety officials. Fiber optics have played a major role in the development of smart textiles as they have in smart structures in general. Optical fiber integration into textile structures (knitted, woven, and non-woven) is presented, and defines the proper methodology for the manufacturing of smart textiles. Samples of fabrics with integrated optical fibers were processed and tested for optical signal transmission. This was done in order to investigate the effect of textile production procedures on optical fiber performance. The tests proved the effectiveness of the developed methodology for integration of optical fibers without changing their optical performance or structural integrity.

  15. Laser beam shaping inside an optical fiber

    International Nuclear Information System (INIS)

    Some laser applications like the injection line of powerful lasers requires a very uniform laser beam spatial profile. Such a profile is usually obtained by using expensive optic components that are difficult to align. A new solution consists of shaping the laser beam not in the open air but inside an optic fiber. We have created a micro-structured optic fiber whose propagation mode is not Gaussian as usual but is of a flattened shape. This optic fiber will replace the optic component dedicated to spatial shaping of the laser beam, this function is usually made by phase mirrors located in the first stage of the amplification process

  16. Laboratory Equipment Type Fiber Optic Refractometer

    Directory of Open Access Journals (Sweden)

    E. F. Carome

    2002-09-01

    Full Text Available Using fiber optics and micro optics technologies we designed aninnovative fiber optic index of refraction transducer that has uniqueproperties. On the base of this transducer a laboratory equipment typefiber optic refractometer was developed for liquid index of refractionmeasurements. Such refractometer may be used for medical,pharmaceutical, industrial fluid, petrochemical, plastic, food, andbeverage industry applications. For example, it may be used formeasuring the concentrations of aqueous solutions: as the concentrationor density of a solute increase, the refractive index increasesproportionately. The paper describes development work related to designof laboratory type fiber optic refractometer and describes experimentsto evaluation of its basic properties.

  17. Grazing incidence angle based sensing approach integrated with fiber-optic Fourier transform infrared (FO-FTIR) spectroscopy for remote and label-free detection of medical device contaminations

    International Nuclear Information System (INIS)

    Contamination of medical devices has become a critical and prevalent public health safety concern since medical devices are being increasingly used in clinical practices for diagnostics, therapeutics and medical implants. The development of effective sensing methods for real-time detection of pathogenic contamination is needed to prevent and reduce the spread of infections to patients and the healthcare community. In this study, a hollow-core fiber-optic Fourier transform infrared spectroscopy methodology employing a grazing incidence angle based sensing approach (FO-FTIR-GIA) was developed for detection of various biochemical contaminants on medical device surfaces. We demonstrated the sensitivity of FO-FTIR-GIA sensing approach for non-contact and label-free detection of contaminants such as lipopolysaccharide from various surface materials relevant to medical device. The proposed sensing system can detect at a minimum loading concentration of approximately 0.7 ?g/cm2. The FO-FTIR-GIA has the potential for the detection of unwanted pathogen in real time

  18. Grazing incidence angle based sensing approach integrated with fiber-optic Fourier transform infrared (FO-FTIR) spectroscopy for remote and label-free detection of medical device contaminations

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Moinuddin, E-mail: moinuddin.hassan@fda.hhs.gov; Ilev, Ilko [Optical Therapeutics and Medical Nanophotonics Laboratory, Division of Biomedical Physics, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, Maryland 20993 (United States)

    2014-10-15

    Contamination of medical devices has become a critical and prevalent public health safety concern since medical devices are being increasingly used in clinical practices for diagnostics, therapeutics and medical implants. The development of effective sensing methods for real-time detection of pathogenic contamination is needed to prevent and reduce the spread of infections to patients and the healthcare community. In this study, a hollow-core fiber-optic Fourier transform infrared spectroscopy methodology employing a grazing incidence angle based sensing approach (FO-FTIR-GIA) was developed for detection of various biochemical contaminants on medical device surfaces. We demonstrated the sensitivity of FO-FTIR-GIA sensing approach for non-contact and label-free detection of contaminants such as lipopolysaccharide from various surface materials relevant to medical device. The proposed sensing system can detect at a minimum loading concentration of approximately 0.7 ?g/cm{sup 2}. The FO-FTIR-GIA has the potential for the detection of unwanted pathogen in real time.

  19. Optical fiber sensors for harsh environments

    Science.gov (United States)

    Xu, Juncheng; Wang, Anbo

    2007-02-06

    A diaphragm optic sensor comprises a ferrule including a bore having an optical fiber disposed therein and a diaphragm attached to the ferrule, the diaphragm being spaced apart from the ferrule to form a Fabry-Perot cavity. The cavity is formed by creating a pit in the ferrule or in the diaphragm. The components of the sensor are preferably welded together, preferably by laser welding. In some embodiments, the entire ferrule is bonded to the fiber along the entire length of the fiber within the ferrule; in other embodiments, only a portion of the ferrule is welded to the fiber. A partial vacuum is preferably formed in the pit. A small piece of optical fiber with a coefficient of thermal expansion chosen to compensate for mismatches between the main fiber and ferrule may be spliced to the end of the fiber.

  20. Multimode Waveguide Devices For Fiber Optic Instrumentation

    Science.gov (United States)

    Boiarski, A. A.; Sriram, S.

    1988-12-01

    Multimode polymer waveguide circuit fabrication techniques were used to produce several low-cost devices applicable to fiber optic sensor instruments. A 2x1 coupler with 3% reference tap was constructed with 250 and 500 #m diameter plastic fiber pigtails. This coupler had a 2 dB excess loss and could be used to replace the bulk-optic, 3 dB beamsplitter in a fiber optic instrumentation package. Further, a miniature fiber-tipped pressure sensor was produced using waveguide circuit-based photofabrication principles. This device could provide a disposable, catheter-tipped sensor for blood pressure monitoring.

  1. Utilizing simple FBG-based erbium-doped fiber architecture for remote temperature sensing

    Science.gov (United States)

    Yeh, C. H.; Chow, C. W.; Chen, J. Y.; Chen, H. Z.; Chen, J. H.; Liu, W. F.

    2015-10-01

    In this work, we demonstrate experimentally an erbium-doped fiber (EDF) ring laser structure for remote temperature sensing by using fiber Bragg gratings (FBGs) in C-band. Based on the proposed EDF laser configuration, the remote temperature sensing distance is achieved at 50 km. Here, ten FBGs are employed at the remote side for temperature sensing. By tuning the optical tunable filter (TF), the corresponding Bragg wavelength from each FBG can be monitored in the proposed EDF laser. As a result, in the temperature range from 20 to 82 °C, the maximum drift of Bragg wavelength can be detected at 0.84?nm.

  2. Nanocrystalline samarium oxide coated fiber optic gas sensor

    International Nuclear Information System (INIS)

    Highlights: • This fiber optic gas sensor works at room temperature. • As-prepared and annealed Sm2O3 nanoparticles are act as sensor materials. • Sm2O3 clad modified fiber detect the ammonia, ethanol and methanol gases. • The response of evanescent wave loss has been studied for different concentrations. - Abstract: Nanocrystalline Sm2O3 coated fiber optic sensor is proposed for detecting toxic gases such as ammonia, methanol and ethanol vapors. Sm2O3 in the as prepared form as well as annealed form have been used as gas sensing materials, by making them as cladding of a PMMA fiber. The spectral characteristics of the Sm2O3 gas sensor are presented for ammonia, methanol and ethanol gases with different concentrations ranging from 0 to 500 ppm. The sensor exhibits a linear variation in the output light intensity with the concentration. The enhanced gas sensitivity and selectivity of the sensor for ethanol is discussed briefly

  3. GFOC Project results: High Temperature / High Pressure, Hydrogen Tolerant Optical Fiber

    Energy Technology Data Exchange (ETDEWEB)

    E. Burov; A. Pastouret; E. Aldea; B. Overton; F. Gooijer; A. Bergonzo

    2012-02-12

    Tests results are given for exposure of multimode optical fiber to high temperatures (300 deg. C) and high partial pressure (15 bar) hydrogen. These results demonstrate that fluorine down doped optical fibers are much more hydrogen tolerant than traditional germanium doped multimode optical fibers. Also demonstrated is the similar hydrogen tolerance of carbon coated and non-carbon coated fibers. Model for reversible H2 impact in fiber versus T{sup o}C and H2 pressure is given. These results have significant impact for the longevity of use for distributed temperature sensing applications in harsh environments such as geothermal wells.

  4. Radiation cured coatings for fiber optics

    International Nuclear Information System (INIS)

    A continuous protective coating is formed on a fiber optic by coating the fiber optic in a bath of a liquid radiation curable composition at a temperature up to 900C and exposing the coated conductor to ultraviolet or high energy ionizing radiation to cure the coating

  5. Fiber-optic liquid level sensor

    Science.gov (United States)

    Weiss, Jonathan D. (Albuquerque, NM)

    1991-01-01

    A fiber-optic liquid level sensor measures the height of a column of liquid through the hydrostatic pressure it produces. The sensor employs a fiber-optic displacement sensor to detect the pressure-induced displacement of the center of a corrugated diaphragm.

  6. Metal-Coated Optical Fibers for High Temperature Applications

    Science.gov (United States)

    Zeakes, Jason; Murphy, Kent; Claus, Richard; Greene, Jonathan; Tran, Tuan

    1996-01-01

    This poster will highlight on-going research at the Virginia Tech Fiber & Electro-Optics Research Center (FEORC) in the area of thin films on optical fibers. Topics will include the sputter deposition of metals and metal; alloys onto optical fiber and fiber optic sensors for innovative applications. Specific information will be available on thin film fiber optic hydrogen sensors, corrosion sensors, and metal-coated optical fiber for high temperature aerospace applications.

  7. Radiation resistance of the optical fiber

    International Nuclear Information System (INIS)

    Recently attention is paid to the radiation resistance, especially the increment in transmission loss, of the optical fiber. That is, the loss increment after its use under low dose rate for 20 years - 25 years is estimated for the purpose of design of the system. In the optical fiber having a Ge doped quartz core without metallic impurities, the loss increment is known to be dependent on the dose rate similarly to the case of pure quartz. The loss increment of this optical fiber was estimated for the extended exposure at low dose rate. The loss increment in the wholly-synthetic, Ge doped core, optical fiber is negligibly small; its initial loss is small and it is in a high band. The optical fiber is thus widely applicable for the system under radiation requiring large-capacity transmission. (Mori, K.)

  8. Feasibility Study on Fiber-optic Radiation Sensor for Remote Gamma-ray Spectroscopy

    International Nuclear Information System (INIS)

    In this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors. As a result, the BGO was suitable for the sensing probe of fiber-optic radiation sensor due to its high scintillation output and exact photoelectric peak for the gamma-ray energy. The basic principle of radiation detection is to detect the signals caused by interactions between radiations and materials. There are various types of radiation detectors depending on types of radiation to be detected and physical quantities to be measured. As one of the radiation detectors, a fiber-optic radiation sensor using a scintillator and an optical fiber has two advantages such as no space restraint and remote sensing. Moreover, in nuclear environments, this kind of sensor has immunities for electromagnetic field, temperature, and pressure. Thus, the fiber-optic radiation sensor can be used in various fields including nondestructive inspection, radioactive waste management, nuclear safety, radiodiagnosis and radiation therapy. As a fundamental study of the fiber-optic radiation sensor for remote gamma-ray spectroscopy, in this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors

  9. 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...

  10. A cylindrical-core fiber-optic oxygen sensor based on fluorescence quenching of a platinum complex immobilized in a polymer matrix

    OpenAIRE

    Chen, R; Farmery, AD; Obeid, A.; Hahn, CEW

    2012-01-01

    A miniature (200 ?m in diameter) cylindrical-core fiber-optic oxygen sensor has been developed for measuring rapid change in oxygen partial pressure (pO 2). The fiber-optic sensing element is based on a cylindrical-core waveguide structure formed by coating a thin medical grade polymer sensing film that contains immobilized Pt(II) complexes on silica optical fiber. The performance such as sensitivity and time response of the fiber-optic oxygen sensors were evaluated...

  11. Method and apparatus for distributed sensing of volatiles using a long period fiber grating sensor with modulated plastic coating for environmental monitoring

    Science.gov (United States)

    Ponce, Adrian (Inventor); Kossakovski, Dmitri A. (Inventor); Bearman, Gregory H. (Inventor)

    2010-01-01

    Optical time domain reflectometry caused by absorption of a volatile or analyte into the fiber optic cladding is used as an optical nose. The fiber optics (14) are covered with a gas permeable film (44) which is patterned to leave millimeter wide gas permeable notches (48a-48d). The notches contain a sensing polymer that responds to different gases by expanding or contracting.

  12. Real time sensing of structural glass fiber reinforced composites by using embedded PVA - carbon nanotube fibers

    OpenAIRE

    Marioli-Riga Z.; Bartholome C.; Alexopoulos N.; Poulin P.

    2010-01-01

    Polyvinyl alcohol - carbon nanotube (PVA-CNT) fibers had been embedded to glass fiber reinforced polymers (GFRP) for the structural health monitoring of the composite material. The addition of the conductive PVA-CNT fiber to the nonconductive GFRP material aimed to enhance its sensing ability by means of the electrical resistance measurement method. The test specimen’s response to mechanical load and the in situ PVA-CNT fiber’s electrical resistance measurements were correlated for sens...

  13. Fiber optic D dimer biosensor

    Science.gov (United States)

    Glass, Robert S. (Livermore, CA); Grant, Sheila A. (Pleasanton, CA)

    1999-01-01

    A fiber optic sensor for D dimer (a fibrinolytic product) can be used in vivo (e.g., in catheter-based procedures) for the diagnosis and treatment of stroke-related conditions in humans. Stroke is the third leading cause of death in the United States. It has been estimated that strokes and stroke-related disorders cost Americans between $15-30 billion annually. Relatively recently, new medical procedures have been developed for the treatment of stroke. These endovascular procedures rely upon the use of microcatheters. These procedures could be facilitated with this sensor for D dimer integrated with a microcatheter for the diagnosis of clot type, and as an indicator of the effectiveness, or end-point of thrombolytic therapy.

  14. Polarization Dependence Suppression of Optical Fiber Grating Sensor in a ?-Shifted Sagnac Loop Interferometer

    OpenAIRE

    Jaebum Son; Min-Kyoung Lee; Myung Yung Jeong; Chang-Seok Kim

    2010-01-01

    In the sensing applications of optical fiber grating, it is necessary to reduce the transmission-type polarization dependence to isolate the sensing parameter. It is experimentally shown that the polarization-dependent spectrum of acousto-optic long-period fiber grating sensors can be suppressed in the transmission port of a ?-shifted Sagnac loop interferometer. General expressions for the transmittance and reflectance are derived for transmission-type, reflection-type, and partially reflecti...

  15. Fiber optic liquid level sensor system for aerospace applications

    Science.gov (United States)

    Kazemi, Alex A.; Yang, Chenging; Chen, Shiping

    2014-09-01

    Detection of the liquid level in fuel tank becomes a critical element for the safety and efficiency in aerospace operations. Two liquid level sensing techniques are presented in this paper. The first technique is based on optical fiber Long Period Gratings (LPG). In this system, the full length of a specially fabricated fiber is the body of the probe because the length of the sensing fiber that is submerged in the liquid can be detected by the interrogation system. The second system based on Total Internal Reflection (TIR) uses optical fibers to guide light to and from an array of point probes. These probes are specially fabricated, miniature optical components which reflects a substantial amount of light back into the lead fiber when the probe is gas but almost no light when it is in liquid. A detailed theoretical study by computer simulation was carried out on these two techniques in order to determine which technique was more suitable for experimental investigation. The study revealed that although the first technique may provide more potential benefits in terms of weight and easy installation; a number of technical challenges make it not suitable for a short term solution. The second, probe array based technique, on the other hand, is more mature technically. The rest of the research program was therefore focused on the experimental investigation of the probe array detection technique and the test results are presented in this paper.

  16. Poly aniline Nano fiber as Modified Cladding for Optical Fiber Sensor to Detect Acetone Vapor

    International Nuclear Information System (INIS)

    In this research, we used poly aniline nano fiber as modified cladding material for a fiber optic sensor system to detect the acetone vapor. The sensor was designed based on variation of evanescent field absorption on the core-modified cladding interface when exposed with varied acetone vapor. Poly aniline nano fiber synthesized by interfacial polymerization was coated onto the un-cladded core and acts as sensing element. Response of the fiber optic sensor was investigated by measuring the transmission light intensity via fiber optic sensor system while exposed with acetone vapor. Based on the sensor response curve, it is obtained a very fast response time of 30 s and recovery time of 10 s. The fiber optic sensor also exhibits a good reversibility and repeatability. Sensitivity of the sensor to variation of acetone vapor pressure was obtained 1.25 %/mmHg, that means the transmission intensity of the sensor changes 1.25 % for acetone vapor change of 1 mmHg. (author)

  17. Implementation Of Fiber Optics In U. S. Naval Combatants

    Science.gov (United States)

    Johnston, R. A.; Stewart, R. C.

    1987-12-01

    This paper describes a program wherein fiber optic technology was introduced into the U. S. Navy's AEGIS Cruisers. This program was sponsored and funded for the most part by Naval Sea Systems Command and represents the first significant effort involving naval vessels. Although specific to one ship class, the program achievements are applicable to most naval as well as commercial ships. The process of transitioning fiber optic technology from the laboratory or commercial sector to a military ship is described. The issues addressed and problems resolved during this transition are discussed. Some of the primary issues include transmission data rates, ship producibility and environmental concerns such as temperature extremes, shock, vibration, ionizing radiation, toxic materials, etc. Additionally, the advantages of fiber optic technology specific to U. S. Naval ships are explained. Of particular importance are the developments that evolved from the AEGIS Cruiser program. Developments include a unique cable design, junction boxes, connectors, a splice, emergency repair procedures, a remote motor control system, a torsionmeter system, and a family of sensors and switches. The overall program resulted in the installation of fiber optic systems on three U. S. Navy ships. These installation projects are described along with some of the lessons learned. The paper concludes that the past issues that prevented the use of fiber optic technology in naval ships have been addressed and resolved. Fiber optics has successfully been introduced into naval combatants in data transmission, control, and sensing applications. Normal producibility has been considered such that fiber optic systems have been installed in almost routine fashion by a commercial shipyard. Additionally, human factor considerations have resulted in little or no additional training being required for operational and maintenance personnel.

  18. A novel distributed optic fiber transduser for landslides monitoring

    Science.gov (United States)

    Zhu, Zheng-Wei; Liu, Dong-Yan; Yuan, Qiao-Ying; Liu, Bang; Liu, Jing-Cheng

    2011-07-01

    Unstable slopes have been monitored since the beginning of the last century. Current electro-optic detection technology can achieve automatic monitoring remotely with high safety and includes such methods as time domain reflectometry, optical time domain reflectometry and Brillouin optical time domain reflectometry. However, these technologies cannot simultaneously meet the requirements of distributed sensing, high initial measurement accuracy, large sliding distance and high dynamic range. Based on the space frame theory of reinforced concrete beams, this study presents an innovative design for a distributed optic fiber sensor: a novel transduser with a bowknot. Using the optic fiber microbending loss mechanism and optical time domain reflectometry technology, bending and shear tests based on the combined fiber sensor are conducted, and the vertical displacement of midspan, optical fiber sliding distance and loss data under three different spans are collected. Feasibility study and economic analysis of the transduser used for landslide monitoring are also presented. The results show that the maximum sliding distance of our transduser is 21.8, 26.5 and 30.6 mm with corresponding initial accuracies of 1.2, 2.3 and 3.3 mm, and the dynamic ranges are 0-20.6, 0-23.2 and 0-27.3 mm. The cost of the transduser is economical at $0.15/m, which demonstrates promising economic application, high monitoring effectiveness and stability in monitoring civil works, such as slope, dam and tunnel construction and measurement.

  19. Low-cost fiber-optic chemochromic hydrogen detector

    Energy Technology Data Exchange (ETDEWEB)

    Benson, D.K.; Tracy, C.E.; Hishmeh, G.; Ciszek, P.; Lee, S.H. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    The ability to detect hydrogen gas leaks economically and with inherent safety is an important technology that could facilitate commercial acceptance of hydrogen fuel in various applications. In particular, hydrogen fueled passenger vehicles will require hydrogen leak detectors to signal the activation of safety devices such as shutoff valves, ventilating fans, alarms, etc. Such detectors may be required in several locations within a vehicle--wherever a leak could pose a safety hazard. It is therefore important that the detectors be very economical. This paper reports progress on the development of low-cost fiber-optic hydrogen detectors intended to meet the needs of a hydrogen-fueled passenger vehicle. In the design, the presence of hydrogen in air is sensed by a thin-film coating at the end of a polymer optical fiber. When the coating reacts reversibly with the hydrogen, its optical properties are changed. Light from a central electro-optic control unit is projected down the optical fiber where it is reflected from the sensor coating back to central optical detectors. A change in the reflected intensity indicates the presence of hydrogen. The fiber-optic detector offers inherent safety by removing all electrical power from the leak sites and offers reduced signal processing problems by minimizing electromagnetic interference. Critical detector performance requirements include high selectivity, response speed and durability as well as potential for low-cost production.

  20. Fiber-optic magnetic-field imaging.

    Science.gov (United States)

    Fedotov, I V; Doronina-Amitonova, L V; Sidorov-Biryukov, D A; Safronov, N A; Blakley, S; Levchenko, A O; Zibrov, S A; Fedotov, A B; Kilin, S Ya; Scully, M O; Velichansky, V L; Zheltikov, A M

    2014-12-15

    We demonstrate a scanning fiber-optic probe for magnetic-field imaging where nitrogen-vacancy (NV) centers are coupled to an optical fiber integrated with a two-wire microwave transmission line. The electron spin of NV centers in a diamond microcrystal attached to the tip of the fiber probe is manipulated by a frequency-modulated microwave field and is initialized by laser radiation transmitted through the optical tract of the fiber probe. The two-dimensional profile of the magnetic field is imaged with a high speed and high sensitivity using the photoluminescence spin-readout return from NV centers, captured and delivered by the same optical fiber. PMID:25503039

  1. Quantitative broadband chemical sensing in air-suspended solid-core fibers

    CERN Document Server

    Euser, T G; Farrer, N J; Scharrer, M; Sadler, P J; Russell, P St J

    2007-01-01

    We demonstrate a quantitative broadband fiber sensor, based on evanescent field sensing in the cladding holes of an air-suspended solid-core photonic crystal fiber. We discuss the fabrication process, together with the structural- and optical characterization of a range of different fibers. Measured mode profiles are in good agreement with finite element method calculations made without free parameters. The fraction of the light in the hollow cladding can be tuned via the core diameter of the fiber. Dispersion measurements are in excellent agreement with theory and demonstrate tuning of the zero dispersion wavelength via the core diameter. Optimum design parameters for absorption sensors are discussed using a general parameter diagram. From our analysis, we estimate that a sensitivity increase of three orders of magnitude is feasible compared to standard cuvette measurements. Our study applies to both liquid and gas fiber sensors. We demonstrate the applicability of our results to liquid chemical sensing by m...

  2. Enhancing Optical Communications with Brand New Fibers

    DEFF Research Database (Denmark)

    Morioka, Toshio; Awaji, Yoshinari; Ryf, Roland; Winzer, Peter; Richardson, David; Poletti, Francesco

    2012-01-01

    Optical fibers have often been considered to offer effectively infinite capacity to support the rapid traffic growth essential to our information society. However, as demand has grown and technology has developed, we have begun to realize that there is a fundamental limit to fiber capacity of ~ 100 Tb/s per fiber for systems based on conventional single-core single-mode optical fiber as the transmission medium. This limit arises from the interplay of a number of factors including the Shannon lim...

  3. Clinical Measurements Using Fiber Optics And Optrodes

    Science.gov (United States)

    Milanovich, Fred P.; Hirschfeld, Tomas B.; Wang, Francis T.; Klainer, Stanley M.; Walt, David

    1984-10-01

    Fiber optics, optrodes, and fluorescence spectroscopy have been combined to form the new technology of remote fiber fluorimetry (RFF). Both in-vivo and in-vitro clinical measurements can be made by using this technique. The optrode, a fiber termination with preselected chemical or physical properties, is attached to the distal end of the optical fiber so that specific, in-situ measurements can be made. RFF systems for pH, blood pressure, oxygen, and carbon dioxide are being completed, and other optrodes are in the development stages.

  4. High capacity fiber optic sensor networks using hybrid multiplexing techniques and their applications

    Science.gov (United States)

    Sun, Qizhen; Li, Xiaolei; Zhang, Manliang; Liu, Qi; Liu, Hai; Liu, Deming

    2013-12-01

    Fiber optic sensor network is the development trend of fiber senor technologies and industries. In this paper, I will discuss recent research progress on high capacity fiber sensor networks with hybrid multiplexing techniques and their applications in the fields of security monitoring, environment monitoring, Smart eHome, etc. Firstly, I will present the architecture of hybrid multiplexing sensor passive optical network (HSPON), and the key technologies for integrated access and intelligent management of massive fiber sensor units. Two typical hybrid WDM/TDM fiber sensor networks for perimeter intrusion monitor and cultural relics security are introduced. Secondly, we propose the concept of "Microstructure?Optical X Domin Refecltor (M-OXDR)" for fiber sensor network expansion. By fabricating smart micro-structures with the ability of multidimensional encoded and low insertion loss along the fiber, the fiber sensor network of simple structure and huge capacity more than one thousand could be achieved. Assisted by the WDM/TDM and WDM/FDM decoding methods respectively, we built the verification systems for long-haul and real-time temperature sensing. Finally, I will show the high capacity and flexible fiber sensor network with IPv6 protocol based hybrid fiber/wireless access. By developing the fiber optic sensor with embedded IPv6 protocol conversion module and IPv6 router, huge amounts of fiber optic sensor nodes can be uniquely addressed. Meanwhile, various sensing information could be integrated and accessed to the Next Generation Internet.

  5. Fiber-Optic Interferometry Using Narrowband Light Source and Electrical Spectrum Analyzer: Influence on Brillouin Measurement

    OpenAIRE

    Mizuno, Yosuke; Hayashi, Neisei; Nakamura, Kentaro

    2014-01-01

    We observe an interference pattern using a simple fiber-optic interferometer consisting of an electrical spectrum analyzer and a narrowband light source, which is commonly employed for observing the Brillouin gain spectrum. This interference pattern expands well beyond the frequency range corresponding to the Brillouin frequency shift in silica fibers (approximately 11 GHz at 1550 nm). Using both silica single-mode and polymer optical sensing fibers, we then experimentally p...

  6. Optical display for radar sensing

    Science.gov (United States)

    Szu, Harold; Hsu, Charles; Willey, Jefferson; Landa, Joseph; Hsieh, Minder; Larsen, Louis V.; Krzywicki, Alan T.; Tran, Binh Q.; Hoekstra, Philip; Dillard, John T.; Krapels, Keith A.; Wardlaw, Michael; Chu, Kai-Dee

    2015-05-01

    Boltzmann headstone S = kB Log W turns out to be the Rosette stone for Greek physics translation optical display of the microwave sensing hieroglyphics. The LHS is the molecular entropy S measuring the degree of uniformity scattering off the sensing cross sections. The RHS is the inverse relationship (equation) predicting the Planck radiation spectral distribution parameterized by the Kelvin temperature T. Use is made of the conservation energy law of the heat capacity of Reservoir (RV) change T ? S = -?E equals to the internal energy change of black box (bb) subsystem. Moreover, an irreversible thermodynamics ? S > 0 for collision mixing toward totally larger uniformity of heat death, asserted by Boltzmann, that derived the so-called Maxwell-Boltzmann canonical probability. Given the zero boundary condition black box, Planck solved a discrete standing wave eigenstates (equation). Together with the canonical partition function (equation) an average ensemble average of all possible internal energy yielded the celebrated Planck radiation spectral (equation) where the density of states (equation). In summary, given the multispectral sensing data (equation), we applied Lagrange Constraint Neural Network (LCNN) to solve the Blind Sources Separation (BSS) for a set of equivalent bb target temperatures. From the measurements of specific value, slopes and shapes we can fit a set of Kelvin temperatures T's for each bb targets. As a result, we could apply the analytical continuation for each entropy sources along the temperature-unique Planck spectral curves always toward the RGB color temperature display for any sensing probing frequency.

  7. Thermal Strain Analysis of Optic Fiber Sensors

    Science.gov (United States)

    Her, Shiuh-Chuan; Huang, Chih-Ying

    2013-01-01

    An optical fiber sensor surface bonded onto a host structure and subjected to a temperature change is analytically studied in this work. The analysis is developed in order to assess the thermal behavior of an optical fiber sensor designed for measuring the strain in the host structure. For a surface bonded optical fiber sensor, the measuring sensitivity is strongly dependent on the bonding characteristics which include the protective coating, adhesive layer and the bonding length. Thermal stresses can be generated due to a mismatch of thermal expansion coefficients between the optical fiber and host structure. The optical fiber thermal strain induced by the host structure is transferred via the adhesive layer and protective coating. In this investigation, an analytical expression of the thermal strain and stress in the optical fiber is presented. The theoretical predictions are validated using the finite element method. Numerical results show that the thermal strain and stress are linearly dependent on the difference in thermal expansion coefficients between the optical fiber and host structure and independent of the thermal expansion coefficients of the adhesive and coating. PMID:23385407

  8. Chirped fiber Bragg grating detonation velocity sensing

    Science.gov (United States)

    Rodriguez, G.; Sandberg, R. L.; McCulloch, Q.; Jackson, S. I.; Vincent, S. W.; Udd, E.

    2013-01-01

    An all optical-fiber-based approach to measuring high explosive detonation front position and velocity is described. By measuring total light return using an incoherent light source reflected from a linearly chirped fiber Bragg grating sensor in contact with the explosive, dynamic mapping of the detonation front position and velocity versus time is obtained. We demonstrate two calibration procedures and provide several examples of detonation front measurements: PBX 9502 cylindrical rate stick, radial detonation front in PBX 9501, and PBX 9501 detonation along curved meridian line. In the cylindrical rate stick measurement, excellent agreement with complementary diagnostics (electrical pins and streak camera imaging) is achieved, demonstrating accuracy in the detonation front velocity to below the 0.3% level when compared to the results from the pin data. Finally, an estimate on the linear spatial and temporal resolution of the system shows that sub-mm and sub-?s levels are attainable with proper consideration of the recording speed, detection sensitivity, spectrum, and chirp properties of the grating.

  9. A high-sensitivity chemical sensor based on titania coated optical-fiber long period grating for ammonia sensing in water

    Science.gov (United States)

    Tiwari, D.; James, S. W.; Tatam, R. P.; Korposh, S.; Lee, S. W.

    2015-07-01

    Two highly sensitive ammonia sensors, formed by depositing coatings composed of titanium dioxide (TiO2) onto the cladding of an optical fibre sensing platform, are evaluated. A long period grating (LPG) of period 111 ?m was fabricated in the core of an optical fibre so that the LPG operates at or near the phase matching turning point (PMTP). The first coating that was investigated was composed of TiO2 nanoparticles deposited by liquid phase deposition. The sensor showed high sensitivity and allowed low concentrations of ammonia in water (0.01 ppm) to be detected with a response time of less than 60 sec. The second coating was composed of TiO2 with subsequent layers of poly (allyamine hydrochloride) (PAH), and SiO2 nanospheres infused with a sensitive element composed of porphine. The ammonia adsorption to the porphine compound led to the changes in the LPG's transmission spectrum and allowed 0.1 ppm of ammonia in water to be detected with a response time of less than 60 sec.

  10. The Soliton Transmissions in Optical Fibers

    Directory of Open Access Journals (Sweden)

    Leos Bohac

    2010-01-01

    Full Text Available The objective of this paper is to familiarize readers with the basic analytical propagation model of short optical pulses in optical fiber. Based on this model simulation of propagation of the special type of pulse, called a soliton, will be carried out. A soliton transmission is especially attractive in the fiber optic telecommunication systems as it does not change a pulses shape during propagating right-down the fiber link to the receiver. The model of very short pulse propagation is based on the numerical solution of the nonlinear Schroedinger equation (NLSE, although in some specific cases it is possible to solve it analytically.

  11. Fiber optic communications fundamentals and applications

    CERN Document Server

    Kumar, Shiva

    2014-01-01

    Fiber-optic communication systems have advanced dramatically over the last four decades, since the era of copper cables, resulting in low-cost and high-bandwidth transmission. Fiber optics is now the backbone of the internet and long-distance telecommunication. Without it we would not enjoy the benefits of high-speed internet, or low-rate international telephone calls. This book introduces the basic concepts of fiber-optic communication in a pedagogical way. The important mathematical results are derived by first principles rather than citing research articles. In addition, physical interpre

  12. Side-emitting fiber optic position sensor

    Science.gov (United States)

    Weiss, Jonathan D. (Albuquerque, NM)

    2008-02-12

    A side-emitting fiber optic position sensor and method of determining an unknown position of an object by using the sensor. In one embodiment, a concentrated beam of light source illuminates the side of a side-emitting fiber optic at an unknown axial position along the fiber's length. Some of this side-illuminated light is in-scattered into the fiber and captured. As the captured light is guided down the fiber, its intensity decreases due to loss from side-emission away from the fiber and from bulk absorption within the fiber. By measuring the intensity of light emitted from one (or both) ends of the fiber with a photodetector(s), the axial position of the light source is determined by comparing the photodetector's signal to a calibrated response curve, look-up table, or by using a mathematical model. Alternatively, the side-emitting fiber is illuminated at one end, while a photodetector measures the intensity of light emitted from the side of the fiber, at an unknown position. As the photodetector moves further away from the illuminated end, the detector's signal strength decreases due to loss from side-emission and/or bulk absorption. As before, the detector's signal is correlated to a unique position along the fiber.

  13. Temperature sensing of micron scale polymer fibers using fiber Bragg gratings

    Science.gov (United States)

    Zhou, J.; Zhang, Y.; Mulle, M.; Lubineau, G.

    2015-08-01

    Highly conductive polymer fibers are key components in the design of multifunctional textiles. Measuring the voltage/temperature relationships of these fibers is very challenging due to their very small diameters, making it impossible to rely on classical temperature sensing techniques. These fibers are also so fragile that they cannot withstand any perturbation from external measurement systems. We propose here, a non-contact temperature measurement technique based on fiber Bragg gratings (FBGs). The heat exchange is carefully controlled between the probed fibers and the sensing FBG by promoting radiation and convective heat transfer rather than conduction, which is known to be poorly controlled. We demonstrate our technique on a highly conductive Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS)-based fiber. A non-phenomenological model of the sensing system based on meaningful physical parameters is validated towards experimental observations. The technique reliably measures the temperature of the polymer fibers when subjected to electrical loading.

  14. Electric field sensor array from cavity resonance between optical D-fiber and multiple slab waveguides.

    Science.gov (United States)

    Gibson, Richard; Selfridge, Richard; Schultz, Stephen

    2009-07-01

    We develop an electric field sensor array based on optical fiber interrogation with electro-optic crystals to measure high energy electromagnetic pulses. D-shaped optical fiber provides the platform for resonant coupling with multiple electro-optic crystals, allowing an array of sensing points on a single strand of optical fiber. Because of its small size, flexibility, and dielectric composition, this sensor array is suitable for performing electric-field analysis at multiple points within an electronic device. Using lithium niobate and potassium titanyl phosphate crystals, the sensor array is sensitive to fields as low as 100 V/m. PMID:19571925

  15. Stabilizing Fiber-Optic Transmission Lines

    Science.gov (United States)

    Lutes, G. F.; Lau, K. Y.

    1984-01-01

    Voltage-controlled optical phase shifter is key. Optical phase shifter stabilizes propagation delay of fiber-optic transmission line by compensating for temperature and pressure effects. Applicable to phased array antenna systems and very-long-baseline interferometer distribution systems.

  16. Attenuation in silica-based optical fibers

    DEFF Research Database (Denmark)

    Wandel, Marie Emilie

    2006-01-01

    In this thesis on attenuation in silica based optical fibers results within three main topics are reported. Spectral attenuation measurements on transmission fibers are performed in the wide wavelength range 290 nm – 1700 nm. The measured spectral attenuation is analyzed with special emphasis on absorption peaks in order to investigate the cause of an unusual high attenuation in a series of transmission fibers. Strong indications point to Ni2+ in octahedral coordination as being the cause of the high attenuation. The attenuation of fibers having a high core refractive index is analyzed and the cause of the high attenuation measured in such fibers is described as being due to scattering of light on fluctuations of the core diameter. A novel semi-empirical model for predicting the attenuation of high index fibers is presented. The model is shown to be able to predict the attenuation of high index fibers having viscosity profiles similar to those for which the model was calibrated but not of fibers having dissimilar viscosity profiles. The model is improved by including the viscosity profiles of the fibers. A set of fibers is produced demonstrating that by carefully designing the index profile as well as the viscosity profile a lower attenuation of high index fibers can be obtained. The design of dispersion compensating fibers using the super mode approach is described, the object being to design dispersion compensating fibers for dispersion compensating fiber modules having a low attenuation, described by a high figure of merit. The major trade offs encountered when designing dispersion compensating fibers with high figure of merit are to obtain a very negative dispersion, low attenuation and low micro bend loss at the same time. The model for predicting the attenuation of high index fibers is used for the optimization process and results are reported of a dispersion compensating fiber having a record high figure of merit of 470 ps/(nm dB).

  17. Attenuation in silica-based optical fibers

    DEFF Research Database (Denmark)

    Wandel, Marie Emilie

    2006-01-01

    In this thesis on attenuation in silica based optical fibers results within three main topics are reported. Spectral attenuation measurements on transmission fibers are performed in the wide wavelength range 290 nm – 1700 nm. The measured spectral attenuation is analyzed with special emphasis on absorption peaks in order to investigate the cause of an unusual high attenuation in a series of transmission fibers. Strong indications point to Ni2+ in octahedral coordination as being the cause of the...

  18. Fiber optic systems in the UV region

    Science.gov (United States)

    Huebner, Michael; Meyer, H.; Klein, Karl-Friedrich; Hillrichs, G.; Ruetting, Martin; Veidemanis, M.; Spangenberg, Bernd; Clarkin, James P.; Nelson, Gary W.

    2000-05-01

    Mainly due to the unexpected progress in manufacturing of solarization-reduced all-silica fibers, new fiber-optic applications in the UV-region are feasible. However, the other components like the UV-sources and the detector- systems have to be improved, too. Especially, the miniaturization is very important fitting to the small-sized fiber-optic assemblies leading to compact and mobile UV- analytical systems. Based on independent improvements in the preform and fiber processing, UV-improved fibers with different properties have been developed. The best UV-fiber for the prosed applications is selectable by its short and long-term spectral behavior, especially in the region from 190 to 350 nm. The spectrum of the UV-source and the power density in the fiber have an influence on the nonlinear transmission and the damaging level; however, hydrogen can reduce the UV-defect concentration. After determining the diffusion processes in the fiber, the UV-lifetime in commercially available all-silica fibers can be predicted. Newest results with light from deuterium-lamps, excimer- lasers and 5th harmonics of Nd:YAG laser will be shown. Many activities are in the field of UV-sources. In addition to new UV-lasers like the Nd:YAG laser at 213 nm, a new low- power deuterium-lamp with smaller dimensions has been introduced last year. Properties of this lamp will be discussed, taking into account some of the application requirements. Finally, some new applications with UV-fiber optics will be shown; especially the TLC-method can be improved significantly, combining a 2-row fiber-array with a diode-array spectrometer optimized for fiber-optics.

  19. Dynamic Characterization of Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Andresen, Søren; Yuan, Wu; Bang, Ole

    2012-01-01

    With the increasing interest in fiber sensors based on polymer optical fibers, it becomes fundamental to determine the real applicability and reliability of this type of sensor. The viscoelastic nature of polymers gives rise to questions about the mechanical behavior of the fibers. In particular, concerns on the response in the nonstatic regime find foundation in the viscoelasticity theory. We investigate the effects of such behavior via analysis of the mechanical properties under dynamic excita...

  20. Microstructured optical fibers - Fundamentals and applications

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Bjarklev, Anders Overgaard

    2006-01-01

    In recent years optical fibers having a complex microstructure in the transverse plane have attracted much attention from both researchers and industry. Such fibers can either guide light through total internal reflection or the photonic bandgap effect. Among the many unique applications offered by these fibers are mode guidance in air, highly flexible dispersion engineering, and the use of very heterogeneous material combinations. In this paper, we review the different types and applications of...

  1. Protective coating and hyperthermal atomic oxygen texturing of optical fibers used for blood glucose monitoring

    Science.gov (United States)

    Banks, Bruce A. (Inventor)

    2008-01-01

    Disclosed is a method of producing cones and pillars on polymethylmethacralate (PMMA) optical fibers for glucose monitoring. The method, in one embodiment, consists of using electron beam evaporation to deposit a non-contiguous thin film of aluminum on the distal ends of the PMMA fibers. The partial coverage of aluminum on the fibers is randomly, but rather uniformly distributed across the end of the optical fibers. After the aluminum deposition, the ends of the fibers are then exposed to hyperthermal atomic oxygen, which oxidizes the areas that are not protected by aluminum. The resulting PMMA fibers have a greatly increased surface area and the cones or pillars are sufficiently close together that the cellular components in blood are excluded from passing into the valleys between the cones and pillars. The optical fibers are then coated with appropriated surface chemistry so that they can optically sense the glucose level in the blood sample than that with conventional glucose monitoring.

  2. Electron spin manipulation and readout through an optical fiber

    Science.gov (United States)

    Fedotov, I. V.; Doronina-Amitonova, L. V.; Voronin, A. A.; Levchenko, A. O.; Zibrov, S. A.; Sidorov-Biryukov, D. A.; Fedotov, A. B.; Velichansky, V. L.; Zheltikov, A. M.

    2014-07-01

    The electron spin of nitrogen--vacancy (NV) centers in diamond offers a solid-state quantum bit and enables high-precision magnetic-field sensing on the nanoscale. Implementation of these approaches in a fiber format would offer unique opportunities for a broad range of technologies ranging from quantum information to neuroscience and bioimaging. Here, we demonstrate an ultracompact fiber-optic probe where a diamond microcrystal with a well-defined orientation of spin quantization NV axes is attached to the fiber tip, allowing the electron spins of NV centers to be manipulated, polarized, and read out through a fiber-optic waveguide integrated with a two-wire microwave transmission line. The microwave field transmitted through this line is used to manipulate the orientation of electron spins in NV centers through the electron-spin resonance tuned by an external magnetic field. The electron spin is then optically initialized and read out, with the initializing laser radiation and the photoluminescence spin-readout return from NV centers delivered by the same optical fiber.

  3. Fiber optic sensor for methanol quantification in biodiesel

    Science.gov (United States)

    Kawano, Marianne S.; Kamikawachi, Ricardo Canute; Fabris, José L.; Müller, Marcia

    2014-05-01

    In this work a refractometric sensor for assessment of methanol presence in biodiesel is reported. The transducer relies on the interference between the forward and back propagating modes of a single long period grating, written close to an end-face mirror optical fiber. The sensing method is thermally assisted in order to overcome the drawback caused by the high refractive index (close to the fiber cladding index) of methanol-biodiesel blends at low temperatures. Sensor showed a combined standard uncertainty of 0.6 % v/v of methanol in biodiesel for a confidence level of 68.27%, within the methanol concentration ranging from 0 to 25 % v/v.

  4. Microcontroller Based Mobile Platform with Fiber Optic Sensors

    OpenAIRE

    Dr. Buchade

    2013-01-01

    In the present work a mobile platform with optical fiber sensor was designed, built and tested. The IC 89C51RD2 was used as controller on the platform. The platform was designed with two powered wheels on the back and one free turning wheel on the front. Further the platform was outfitted with proximity, weight and touch plastic fiber sensors. Home position was sensed by touch sensor, the destination by proximity sensor and weight by the load cell sensor. A program was written to move the pla...

  5. Architecture for fiber-optic sensors and actuators in aircraft propulsion systems

    Science.gov (United States)

    Glomb, W. L., Jr.

    1990-01-01

    This paper describes a design for fiber-optic sensing and control in advanced aircraft Electronic Engine Control (EEC). The recommended architecture is an on-engine EEC which contains electro-optic interface circuits for fiber-optic sensors. Size and weight are reduced by multiplexing arrays of functionally similar sensors on a pairs of optical fibers to common electro-optical interfaces. The architecture contains interfaces to seven sensor groups. Nine distinct fiber-optic sensor types were found to provide the sensing functions. Analysis revealed no strong discriminator (except reliability of laser diodes and remote electronics) on which to base a selection of preferred common interface type. A hardware test program is recommended to assess the relative maturity of the technologies and to determine real performance in the engine environment.

  6. Optical Cutting Interruption Sensor for Fiber Lasers

    Directory of Open Access Journals (Sweden)

    Benedikt Adelmann

    2015-09-01

    Full Text Available We report on an optical sensor system attached to a 4 kW fiber laser cutting machine to detect cutting interruptions. The sensor records the thermal radiation from the process zone with a modified ring mirror and optical filter arrangement, which is placed between the cutting head and the collimator. The process radiation is sensed by a Si and InGaAs diode combination with the detected signals being digitalized with 20 kHz. To demonstrate the function of the sensor, signals arising during fusion cutting of 1 mm stainless steel and mild steel with and without cutting interruptions are evaluated and typical signatures derived. In the recorded signals the piercing process, the laser switch on and switch off point and waiting period are clearly resolved. To identify the cutting interruption, the signals of both Si and InGaAs diodes are high pass filtered and the signal fluctuation ranges being subsequently calculated. Introducing a correction factor, we identify that only in case of a cutting interruption the fluctuation range of the Si diode exceeds the InGaAs diode. This characteristic signature was successfully used to detect 80 cutting interruptions of 83 incomplete cuts (alpha error 3.6% and system recorded no cutting interruption from 110 faultless cuts (beta error of 0. This particularly high detection rate in combination with the easy integration of the sensor, highlight its potential for cutting interruption detection in industrial applications.

  7. Fiber Optic Communications Technology. A Status Report.

    Science.gov (United States)

    Hull, Joseph A.

    Fiber optic communications (communications over very pure glass transmission channels of diameter comparable to a human hair) is an emerging technology which promises most improvements in communications capacity at reasonable cost. The fiber transmission system offers many desirable characteristics representing improvements over conventional…

  8. Optical-Fiber-to-Channel-Waveguide Coupler

    Science.gov (United States)

    Ramer, G. O.

    1983-01-01

    Holding device made by etching V-shaped grooves in silicon in coupler close tolerances are achieved for high-efficiency coupling between optical fibers with core diameter of 5 um and 110 um in cross section. Fibers are held in V-shaped grooves on silicon chips.

  9. Optical fibers and sensors for chemistry

    International Nuclear Information System (INIS)

    The idea of using optical fibers in nuclear environment occurs as soon as 1967, too soon for practical realizations. In 1973 the first glass fibers were made available in Switzerland. From 1973 to 1988 three periods show the development: conception from 1973 to 1978, technique strengthening from 1978 to 1983 and nuclear and non nuclear industrial development since 1983. 45 refs., 27 figs

  10. Triboluminescence of silica core optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Zink, J.I.; Beese, W.; Schindler, J.W.; Smiel, A.J.

    1982-01-15

    The triboluminescence spectrum of optical fibers contains two prominent peaks, one at 430 nm and the other at 630 nm. The relative intensities vary with fiber type. The time dependence of the emission is related to the crack rate terminal velocity and to the creation and annihilation of moving cracks.

  11. Bent-fiber intermodal interference based dual-channel fiber optic refractometer.

    Science.gov (United States)

    Zhang, Xinpu; Peng, Wei

    2015-03-23

    We present a novel dual-channel fiber optic interferometer based on intermodal interference from single-mode fiber (SMF) bending. This dual-channel interferometer has simple structure, consisting of two bare fiber semicircular bending regions with different bending radiuses connected by a section of straight fiber. A dual-channel interferometer with bending radiuses of 4 mm and 4.3 mm is fabricated and refractive index (RI) sensing is realized by measuring the wavelength shift of the resonance dips in the transmission spectrum of the dual-channel interferometer. In the RI range of 1.3403 to 1.3726, the corresponding RI sensitivities for these two channels are 207 and 245 nm/RIU (refractive index unit) and the RI resolutions are about 6.57 × 10?? RIU and 5.55 × 10?? RIU, respectively. PMID:25837098

  12. USAF ground fiber optic development program

    Science.gov (United States)

    Sierak, P.; Warren, B.

    Fiber optic development programs of the Air Force are related to applications in the areas of tactical communications, multiterminal communications, and the development of militarized standard transceivers. The Tactical Air Control System (TACS) provides the Air Force component commander with the means to plan and direct tactical air operations, and to coordinate joint operations with other services. A description of the program concerned with tactical fiber optic communications is presented, taking into account this technology in relation to the Air Support Operations Center (ASOC) and the Control and Reporting Center (CRC). Attention is given to CX-4566 26 pair cable characteristics, major ASOC radio data transfer requirements, consolidated TRC-97 link analysis, TPS-43 fiber optic Triax replacement analysis, aspects of distributed data processing, questions of militarized standard transceiver development, and efficient multiplexing techniques for fiber optics.

  13. Fiber Optic Pressure Sensor Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array for measuring air flow pressure at multiple points on the skin of aircrafts for Flight Load Test...

  14. Fiber Optic Pressure Sensor Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array System for measuring air flow pressure at multiple points on the skin of aircrafts for Flight...

  15. A microstructured Polymer Optical Fiber Biosensor

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Jensen, Jesper Bo; Hoiby, Poul E.; Bang, Ole; Pedersen, Lars H.

    2006-01-01

    We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of the complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fibers.

  16. Fiber-Optic Vibration Sensor Based on Multimode Fiber

    Directory of Open Access Journals (Sweden)

    I. Lujo

    2008-06-01

    Full Text Available The purpose of this paper is to present a fiberoptic vibration sensor based on the monitoring of the mode distribution in a multimode optical fiber. Detection of vibrations and their parameters is possible through observation of the output speckle pattern from the multimode optical fiber. A working experimental model has been built in which all used components are widely available and cheap: a CCD camera (a simple web-cam, a multimode laser in visible range as a light source, a length of multimode optical fiber, and a computer for signal processing. Measurements have shown good agreement with the actual frequency of vibrations, and promising results were achieved with the amplitude measurements although they require some adaptation of the experimental model. Proposed sensor is cheap and lightweight and therefore presents an interesting alternative for monitoring large smart structures.

  17. Fiber optics welder having movable aligning mirror

    International Nuclear Information System (INIS)

    A system for welding fiber optic waveguides is disclosed. The ends of the two fibers to be joined are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 450 angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation

  18. Fiber optics welder having movable aligning mirror

    Science.gov (United States)

    Higgins, Robert W. (Los Alamos, NM); Robichaud, Roger E. (Jemez Springs, NM)

    1981-01-01

    A system for welding fiber optic waveguides together. The ends of the two fibers to be joined together are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 45.degree. angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation.

  19. Cluster state quantum computing in optical fibers

    OpenAIRE

    Soudagar, Yasaman; Bussieres, Felix; Berlin, Guido; Lacroix, Suzanne; Fernandez, Jose M.; Godbout, Nicolas

    2006-01-01

    A scheme for the implementation of the cluster state model of quantum computing in optical fibers, which enables the feedforward feature, is proposed. This scheme uses the time-bin encoding of qubits. Following previously suggested methods of applying arbitrary one-qubit gates in optical fibers, two different ways for the realization of fusion gate types I and II for cluster production are proposed: a fully time-bin based encoding scheme and a combination of time-bin and pol...

  20. Fiber optic sensors in the Waterbury Bridge

    Science.gov (United States)

    Fuhr, Peter L.; Spammer, Stephanus J.

    1998-09-01

    The use of fiber optic sensors for the internal state measurements of large civil structures has been increasing in recent years. In many instances, sensors are embedded into the reinforced concrete structure is an attempt to measure a single parameter of interest. Installation and preliminary measurements obtained from a suite of fiber optic sensors which were embedded into a 67 m steel truss bridge spanning the Winooski River in Vermont, USA) are presented.

  1. Adjustable Fiber Optic Microwave Transversal Filters

    Science.gov (United States)

    Shadaram, Mehdi; Lutes, George F.; Logan, Ronald T.; Maleki, Lutfollah

    1994-01-01

    Microwave transversal filters implemented as adjustable tapped fiber optic delay lines developed. Main advantages of these filters (in comparison with conventional microwave transversal filters) are small size, light weight, no need for matching of radio-frequency impedances, no need for shielding against electromagnetic radiation at suboptical frequencies, no need for mechanical tuning, high stability of amplitude and phase, and active control of transfer functions. Weights of taps in fiber optic delay lines adjusted.

  2. Fiber-Optic Discriminator Stabilizes Microwave Oscillator

    Science.gov (United States)

    Logan, Ronald T., Jr.

    1993-01-01

    New fiber-optic delay line discriminator enables stabilization of oscillators directly at microwave output frequency, eliminating need for frequency multiplication. Discriminator is wide-band device, capable of stabilizing outputs of frequency-agile microwave sources over multigigahertz tuning ranges. Use of advanced fiber-optic delay line with wider bandwidth and low noise predicted to yield corresponding improvements in phase-noise performance.

  3. Improved Microwave Fiber-Optic Link

    Science.gov (United States)

    Logan, Ronald T.; Lutes, George F.

    1995-01-01

    High power output and narrow linewidth of Nd:YAG laser and external modulator combination enable higher stability and higher dynamic range fiber-optic transmission of microwave signals over longer distances. System prototype to test concept of high fidelity transmission of received microwave signals over fiber-optic cables, without need to downconvert microwave signals for transmission. Useful in distribution of future, more stable, frequency reference signals, phased array radar systems, and aircraft landing systems using bistatic radar.

  4. Real-time optical fiber dosimeter probe

    Science.gov (United States)

    Croteau, André; Caron, Serge; Rink, Alexandra; Jaffray, David; Mermut, Ozzy

    2011-03-01

    There is a pressing need for a passive optical fiber dosimeter probe for use in real-time monitoring of radiation dose delivered to clinical radiation therapy patients. An optical fiber probe using radiochromic material has been designed and fabricated based on a thin film of the radiochromic material on a dielectric mirror. Measurements of the net optical density vs. time before, during, and after irradiation at a rate of 500cGy/minute to a total dose of 5 Gy were performed. Net optical densities increased from 0.2 to 2.0 for radiochromic thin film thicknesses of 2 to 20 ?m, respectively.

  5. 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.

  6. Development of prototype fiber optics dosimeter for remote radiation measurements

    International Nuclear Information System (INIS)

    Optical fiber dosimetry has been studied as an emerging method of monitoring radiation remotely in difficult to access and hazardous areas and is suitable for use in confined environments that may be inaccessible using existing dosimeters. Being light weight and non intrusive, optical fibers provide several advantages in the field of dosimetry like resistant to electromagnetic interferences. An extrinsic architecture, where the radiation-sensing component is spliced or coupled to an optical fiber, is employed in this work. A prototype single channel fiber optic based remote radiation measurement system with BaFBr:Eu sensor, which has a wide linear dose response, is developed at Radiological Safety Division, IGCAR. High sensitive BaFBr:Eu2+ storage phosphor of 10 mm dia and 4 mm thickness has been successfully synthesized using high temperature solid state diffusion route in a reducing atmosphere. Optical characteristics of the BaFBr:Eu pellet were studied by taking Photoluminescence (PL) and Photo stimulated luminescence (PSL) measurements. PL emission wavelength is measured to be 390 nm. The BaFBr:Eu is irradiated for various absorbed doses in a gamma chamber at 213 Gy/hr using 60Co standard source (BRIT make) available at RSD, IGCAR

  7. Compensated vibrating optical fiber pressure measuring device

    Science.gov (United States)

    Fasching, George E. (Morgantown, WV); Goff, David R. (Christiansburg, VA)

    1987-01-01

    A microbending optical fiber is attached under tension to a diaphragm to se a differential pressure applied across the diaphragm which it causes it to deflect. The fiber is attached to the diaphragm so that one portion of the fiber, attached to a central portion of the diaphragm, undergoes a change in tension; proportional to the differential pressure applied to the diaphragm while a second portion attached at the periphery of the diaphragm remains at a reference tension. Both portions of the fiber are caused to vibrate at their natural frequencies. Light transmitted through the fiber is attenuated by both portions of the tensioned sections of the fiber by an amount which increases with the curvature of fiber bending so that the light signal is modulated by both portions of the fiber at separate frequencies. The modulated light signal is transduced into a electrical signal. The separate modulation signals are detected to generate separate signals having frequencies corresponding to the reference and measuring vibrating sections of the continuous fiber, respectively. A signal proportional to the difference between these signals is generated which is indicative of the measured pressure differential across the diaphragm. The reference portion of the fiber is used to compensate the pressure signal for zero and span changes resulting from ambient temperature and humidity effects upon the fiber and the transducer fixture.

  8. Compact optical fiber sensor smart node.

    Science.gov (United States)

    Lloyd, Seth W; Newman, Jason A; Wilding, Daniel R; Selfridge, Richard H; Schultz, Stephen M

    2007-03-01

    We present a new optical fiber sensor interrogator specifically designed for an embedded instrumentation system. The proposed system consists of a super luminescent diode as a broadband source, a high speed tunable micro-electro-mechanical system (MEMS) filter, photodetector, and an integrated microprocessor for data aggregation, processing, and communication. The entire system is integrated together in a compact package to create a fiber "smart" sensor. The system is capable of interrogating a variety of multiplexed fiber sensors, processing the data, and communicating the results digitally. As an example, the system has been calibrated with an array of fiber Bragg grating sensors. PMID:17411218

  9. Advanced fiber components for optical networks

    OpenAIRE

    Ylä-Jarkko, Kalle

    2004-01-01

    Due to the tremendous growth in data traffic and the rapid development in optical transmission technologies, the limits of the transmission capacity available with the conventional erbium-doped amplifiers (EDFA), optical filters and modulation techniques have nearly been reached. The objective of this thesis is to introduce new fiber-optic components to optical networks to cope with the future growth in traffic and also to bring down the size and cost of the transmission equipment. Improvemen...

  10. Refractive index sensing characterization of a singlemode-claddingless-singlemode fiber structure based fiber ring cavity laser.

    Science.gov (United States)

    Liu, Zhi-bo; Tan, Zhongwei; Yin, Bin; Bai, Yunlong; Jian, Shuisheng

    2014-03-10

    This paper firstly demonstrated the refractive index (RI) characteristics of a singlemode-claddingless-singlemode fiber structure filter based fiber ring cavity laser sensing system. The experiment shows that the lasing wavelength shifts to red side with the ambient RI increase. Linear and parabolic fitting are both done to the measurements. The linear fitting result shows a good linearity for applications in some areas with the determination coefficient of 0.993. And a sensitivity of ~131.64nm/RIU is experimentally achieved with the aqueous solution RI ranging from 1.333 to 1.3707, which is competitively compared to other existing fiber-optic sensors. While the 2 order polynomial fitting function, which determination relationship is higher than 0.999, can be used to some more rigorous monitoring. The proposed fiber laser has a SNR of ~50dB, and 3dB bandwidth ~0.03nm. PMID:24663842

  11. Fiber optics transmission of LV signal

    Science.gov (United States)

    Young, A. D.; Gunter, W. D., Jr.

    1981-01-01

    The first use of a long optical fiber for transmitting megahertz frequencies in a laser velocimeter (LV) receiver system is reported. The fiber comprises a 600-micron diameter fused silica core, a silicon polymer cladding and a plastic jacket. The fiber numerical aperture is 0.22, corresponding to a maximum entrance half-angle of 0.22 rad. The 10-m length used results in a 5.6% attenuation loss. The fiber is found to transmit an 80-MHz signal with excellent resolution. It is established that an LV receiver using fiber optics sends a clean signal in electronically noisy and high-pressure environments and allows velocity measurements in places too small for a photomultiplier tube.

  12. Automated photosensitivity enhancement in optical fiber tapers

    Scientific Electronic Library Online (English)

    Aleksander Sade, Paterno; Valmir de, Oliveira; Hypolito J., Kalinowski.

    2011-06-01

    Full Text Available An alternative technique that uses a flame-brush at high temperature to enhance UV light photosensitivity in an optical fiber is described. An extreme low-cost air aspirated propane-butane mini-torch is used, which produces a lower temperature flame than the one in the flame-brush original technique [...] . It is shown that this change in the previous technique is also capable of improving photosensitivity and allowing the fiber Bragg grating imprinting process to be accelerated. Since the flame-brush photosensitivity enhancement process is designed to operate in an automated fiber taper rig, the process was evaluated in optical fiber tapers with different diameters. In this case, changes in photosensitivity are observed in the tapers in addition to the intrinsic photosensitivity occurring in the pristine fiber without being tapered.

  13. Optical fiber modulator derivates from hollow optical fiber with suspended core.

    Science.gov (United States)

    Yang, Xinghua; Liu, Yanxin; Tian, Fengjun; Yuan, Libo; Liu, Zhihai; Luo, Shenzi; Zhao, Enming

    2012-06-01

    A fiber optic integrated modulation-depth-tunable modulator based on a type of hollow optical fiber with suspended core is proposed and investigated. We synthesized magnetic fluid containing superparamagnetic Fe(3)O(4) nanoparticles and encapsulated it in the hollow optical fiber as the cladding layer of the suspended core by fusing the hollow optical fiber with the multimode optical fibers. The light with a wavelength of 632.8 nm is coupled in and out of the modulating element by a tapering technique. Experimental results show that the light attenuation in the system can be greatly influenced by only 2.0×10(-2) ?L of the magnetic fluid under different magnetic field strengths. The saturated modulation depth is 43% when the magnetic field strength is 489 Oe. The response time of the system is fiber modulators, including other integrated electro-optic devices, such as optical switch, optical fiber filter, and magnetic sensors utilizing the special structure of this hollow optical fiber with suspended core and superparamagnetic magnetic fluid. PMID:22660139

  14. Measurement of Faraday rotation in twisted optical fiber using rotating polarization and analog phase detection

    International Nuclear Information System (INIS)

    We demonstrated phase modulation of rotating linearly polarized light by current-induced Faraday rotation in a single mode optical fiber and used the technique to measure the current in ZT-40M, a Reversed-Field Pinch. We have also demonstrated the practicality of using twisted sensing fiber to overcome the problems associated with linear birefringence

  15. Moire-Fringe-Based Fiber Optic Tiltmeter for Structural Health Monitoring

    International Nuclear Information System (INIS)

    This paper presents a novel fiber optic tiltmeter system for the health monitoring of large-size structures. The system is composed of a sensor head, a light control unit and a signal processing unit. The sensing mechanism of the sensor head is based on a novel integration of the moire fringe phenomenon with fiber optics to achieve a robust performance in addition to its immunity to EM interference, easy ratting, and low cost. In this paper, a prototype of the fiber optic tiltmeter system has been developed successfully. A low-cost light control unit has been developed to drive the system's optic and electronic components. From an experimental test, the fiber optic tiltmeter is proven to be a prospective sensor for the monitoring of the tilting angle of civil structure with a good linearity. Finally, the test also successfully demonstrates the performance and the potential of the novel fiber optic tiltmeter system to monitor the health of civil infrastructures.

  16. Volatile Organic Compound Optical Fiber Sensors: A Review

    Directory of Open Access Journals (Sweden)

    Francisco J. Arregui

    2006-11-01

    Full Text Available Volatile organic compound (VOC detection is a topic of growing interest withapplications in diverse fields, ranging from environmental uses to the food or chemicalindustries. Optical fiber VOC sensors offering new and interesting properties whichovercame some of the inconveniences found on traditional gas sensors appeared over twodecades ago. Thanks to its minimum invasive nature and the advantages that optical fiberoffers such as light weight, passive nature, low attenuation and the possibility ofmultiplexing, among others, these sensors are a real alternative to electronic ones inelectrically noisy environments where electronic sensors cannot operate correctly. In thepresent work, a classification of these devices has been made according to the sensingmechanism and taking also into account the sensing materials or the different methods offabrication. In addition, some solutions already implemented for the detection of VOCsusing optical fiber sensors will be described with detail.

  17. Nonlinear fiber-optic strain sensor based on four-wave mixing in microstructured optical fiber

    DEFF Research Database (Denmark)

    Gu, Bobo; Yuan, Scott Wu

    2012-01-01

    We demonstrate a nonlinear fiber-optic strain sensor, which uses the shifts of four-wave mixing Stokes and anti-Stokes peaks caused by the strain-induced changes in the structure and refractive index of a microstructured optical fiber. The sensor thus uses the inherent nonlinearity of the fiber and does not require any advanced post-processing of the fiber. Strain sensitivity of -0.23 pm/mu epsilon is achieved experimentally and numerical simulations reveal that for the present fiber the sensitivity can be increased to -4.46 pm/mu epsilon by optimizing the pump wavelength and power.

  18. Nonlinear fiber-optic strain sensor based on four-wave mixing in microstructured optical fiber

    DEFF Research Database (Denmark)

    Gu, Bobo; Yuan, Scott Wu; Frosz, Michael H.; Zhang, A. Ping; He, Sailing; Bang, Ole

    2012-01-01

    We demonstrate a nonlinear fiber-optic strain sensor, which uses the shifts of four-wave mixing Stokes and anti-Stokes peaks caused by the strain-induced changes in the structure and refractive index of a microstructured optical fiber. The sensor thus uses the inherent nonlinearity of the fiber and does not require any advanced post-processing of the fiber. Strain sensitivity of -0.23 pm/mu epsilon is achieved experimentally and numerical simulations reveal that for the present fiber the sensiti...

  19. Dynamically tunable optical bottles from an optical fiber

    DEFF Research Database (Denmark)

    Chen, Yuhao; Yan, Lu; Rishøj, Lars Søgaard; Steinvurzel, Paul; Ramachandran, Siddharth

    2012-01-01

    Optical fibers have long been used to impose spatial coherence to shape free-space optical beams. Recent work has shown that one can use higher order fiber modes to create more exotic beam profiles. We experimentally generate optical bottles from Talbot imaging in the coherent superposition of two fiber modes excited with long period gratings, and obtain a 28 ?m × 6 ?m bottle with controlled contrast up to 10.13 dB. Our geometry allows for phase tuning of one mode with respect to the other, whic...

  20. Measuring bacterial growth by refractive index tapered fiber optic biosensor.

    Science.gov (United States)

    Zibaii, Mohammad Ismail; Kazemi, Alireza; Latifi, Hamid; Azar, Mahmoud Karimi; Hosseini, Seyed Masoud; Ghezelaiagh, Mohammad Hossein

    2010-12-01

    A single-mode tapered fiber optic biosensor was utilized for real-time monitoring of the Escherichia coli (E. coli K-12) growth in an aqueous medium. The applied fiber tapers were fabricated using heat-pulling method with waist diameter and length of 6-7?m and 3mm, respectively. The bacteria were immobilized on the tapered surface using Poly-l-Lysine. By providing the proper condition, bacterial population growth on the tapered surface increases the average surface density of the cells and consequently the refractive index (RI) of the tapered region would increase. The adsorption of the cells on the tapered fiber leads to changes in the optical characteristics of the taper. This affects the evanescent field leading to changes in optical throughput. The bacterial growth rate was monitored at room temperature by transmission of a 1558.17nm distributed feedback (DFB) laser through the tapered fiber. At the same condition, after determining the growth rate of E. coli by means of colony counting method, we compared the results with that obtained from the fiber sensor measurements. This novel sensing method, promises new application such as rapid analysis of the presence of bacteria. PMID:20817482

  1. Real time sensing of structural glass fiber reinforced composites by using embedded PVA - carbon nanotube fibers

    Directory of Open Access Journals (Sweden)

    Marioli-Riga Z.

    2010-06-01

    Full Text Available Polyvinyl alcohol - carbon nanotube (PVA-CNT fibers had been embedded to glass fiber reinforced polymers (GFRP for the structural health monitoring of the composite material. The addition of the conductive PVA-CNT fiber to the nonconductive GFRP material aimed to enhance its sensing ability by means of the electrical resistance measurement method. The test specimen’s response to mechanical load and the in situ PVA-CNT fiber’s electrical resistance measurements were correlated for sensing and damage monitoring purposes. The embedded PVA-CNT fiber worked as a sensor in GFRP coupons in tensile loadings. Sensing ability of the PVA-CNT fibers was also demonstrated on an integral composite structure. PVA-CNT fiber near the fracture area of the structure recorded very high values when essential damage occurred to the structure. A finite element model of the same structure was developed to predict axial strains at locations of the integral composite structure where the fibers were embedded. The predicted FEA strains were correlated with the experimental measurements from the PVA-CNT fibers. Calculated and experimental values were in good agreement, thus enabling PVA-CNT fibers to be used as strain sensors.

  2. Fiber Optic Sensors For Detection of Toxic and Biological Threats

    Directory of Open Access Journals (Sweden)

    Jianming Yuan

    2007-12-01

    Full Text Available Protection of public and military personnel from chemical and biological warfareagents is an urgent and growing national security need. Along with this idea, we havedeveloped a novel class of fiber optic chemical sensors, for detection of toxic and biologicalmaterials. The design of these fiber optic sensors is based on a cladding modificationapproach. The original passive cladding of the fiber, in a small section, was removed and thefiber core was coated with a chemical sensitive material. Any change in the opticalproperties of the modified cladding material, due to the presence of a specific chemicalvapor, changes the transmission properties of the fiber and result in modal powerredistribution in multimode fibers. Both total intensity and modal power distribution (MPDmeasurements were used to detect the output power change through the sensing fibers. TheMPD technique measures the power changes in the far field pattern, i.e. spatial intensitymodulation in two dimensions. Conducting polymers, such as polyaniline and polypyrrole,have been reported to undergo a reversible change in conductivity upon exposure tochemical vapors. It is found that the conductivity change is accompanied by optical propertychange in the material. Therefore, polyaniline and polypyrrole were selected as the modifiedcladding material for the detection of hydrochloride (HCl, ammonia (NH3, hydrazine(H4N2, and dimethyl-methl-phosphonate (DMMP {a nerve agent, sarin stimulant},respectively. Several sensors were prepared and successfully tested. The results showeddramatic improvement in the sensor sensitivity, when the MPD method was applied. In thispaper, an overview on the developed class of fiber optic sensors is presented and supportedwith successful achieved results.

  3. High-density, microsphere-based fiber optic DNA microarrays.

    Science.gov (United States)

    Epstein, Jason R; Leung, Amy P K; Lee, Kyong Hoon; Walt, David R

    2003-05-01

    A high-density fiber optic DNA microarray has been developed consisting of oligonucleotide-functionalized, 3.1-microm-diameter microspheres randomly distributed on the etched face of an imaging fiber bundle. The fiber bundles are comprised of 6000-50000 fused optical fibers and each fiber terminates with an etched well. The microwell array is capable of housing complementary-sized microspheres, each containing thousands of copies of a unique oligonucleotide probe sequence. The array fabrication process results in random microsphere placement. Determining the position of microspheres in the random array requires an optical encoding scheme. This array platform provides many advantages over other array formats. The microsphere-stock suspension concentration added to the etched fiber can be controlled to provide inherent sensor redundancy. Examining identical microspheres has a beneficial effect on the signal-to-noise ratio. As other sequences of interest are discovered, new microsphere sensing elements can be added to existing microsphere pools and new arrays can be fabricated incorporating the new sequences without altering the existing detection capabilities. These microarrays contain the smallest feature sizes (3 microm) of any DNA array, allowing interrogation of extremely small sample volumes. Reducing the feature size results in higher local target molecule concentrations, creating rapid and highly sensitive assays. The microsphere array platform is also flexible in its applications; research has included DNA-protein interaction profiles, microbial strain differentiation, and non-labeled target interrogation with molecular beacons. Fiber optic microsphere-based DNA microarrays have a simple fabrication protocol enabling their expansion into other applications, such as single cell-based assays. PMID:12706560

  4. Interrogating adhesion using fiber Bragg grating sensing technology

    Science.gov (United States)

    Rasberry, Roger D.; Rohr, Garth D.; Miller, William K.; Udd, Eric; Blach, Noah T.; Davis, Ryan A.; Olson, Walter R.; Calkins, David; Roach, Allen R.; Walsh, David S.; McElhanon, James R.

    2015-05-01

    The assurance of the integrity of adhesive bonding at substrate interfaces is paramount to the longevity and sustainability of encapsulated components. Unfortunately, it is often difficult to non-destructively evaluate these materials to determine the adequacy of bonding after manufacturing and then later in service. A particularly difficult problem in this regard is the reliable detection/monitoring of regions of weak bonding that may result from poor adhesion or poor cohesive strength, or degradation in service. One promising and perhaps less explored avenue we have recently begun to investigate for this purpose centers on the use of (chirped) fiber Bragg grating sensing technology. In this scenario, a grating is patterned into a fiber optic such that a (broadband) spectral reflectance is observed. The sensor is highly sensitive to local and uniform changes across the length of the grating. Initial efforts to evaluate this approach for measuring adhesive bonding defects at substrate interfaces are discussed. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. Stable transmission of radio frequency signals on fiber links using interferomectric delay sensing

    International Nuclear Information System (INIS)

    The authors demonstrate distribution of a 2850 MHz rf signal over stabilized optical fiber links. For a 2.2 km link they measure an rms drift of 19.4 fs over 60 h, and for a 200 m link an rms drift of 8.4 fs over 20 h. The rf signals are transmitted as amplitude modulation on a continuous optical carrier. Variations in the delay length are sensed using heterodyne interferometry and used to correct the rf phase. The system uses standard fiber telecommunications components.

  6. Miniature all-silica fiber-optic sensor for simultaneous measurement of relative humidity and temperature.

    Science.gov (United States)

    Pevec, Simon; Donlagic, Denis

    2015-12-01

    This Letter presents a miniature fiber-optic sensor created at the tip of an optical fiber suitable for simultaneous measurement of relative humidity and temperature. The proposed sensor is based on two cascaded Fabry-Perot interferometers, the first configured as a relative humidity sensing element made from silica micro-wire coated with thin porous SiO2 layer, and the second as a temperature sensing element made from a segment of a standard single-mode fiber. The sensor has linear characteristics for both measurement parameters and a sensitivity of 0.48 deg/%RH and 3.7 deg/°C. PMID:26625072

  7. Application of optical fiber beam loss monitor

    International Nuclear Information System (INIS)

    KEK is an accelerator complex consisting of an electron-positron injector linac and various types of circular accelerators. In order to protect instruments from radiation damage, discrete beam loss monitors have been installed inside the linac and rings. Although beam losses can be detected using the beam loss monitors (BLMs) or beam position monitors (BPMs), it is difficult to identify the exact position of the loss. The electrons, which strike the duct, lose a fraction of their beam energy, which produces a shower at the location and emits many electrons out of the duct. If an optical fiber is placed inside the beam duct, many of these electrons will pass through the optical fiber where the beam loss is generated. BLMs employing an optical fiber based on Cherenkov radiation are currently being developed and applied to our system. An optical fiber placed into the duct also can be used as a detector for a wire scanner system. Existing wire scanner detectors are set at a fixed position, and detect signals of different beam energies that correspond to the different injection modes. However, the fixed position is not always optimal. Conversely, owing to the optical fiber's distributing nature, optical fiber detector systems containing PMTs enables the effective detection of all signals from various beam modes. We can successfully obtain the clear wire scanner signal by employing this optical fiber system. The measurement of the beam loss at the incidence part of the circular accelerator is also described. The beam loss location as well as the turn-by-turn beam loss can be measured. (author)

  8. ANALYSIS OF OPTICAL FIBER COMMUNICATION SYSTEM USING FREE-SPACE FIBER OPTIC SWITCHES

    OpenAIRE

    Ashutosh Kumar

    2014-01-01

    Optical fiber offers many advantages compared with electric cables, including high bandwidth, low loss, and lightweight, immunity from lightening strikes and the resultant current surges, and no electromagnetic interference. Fiber optic networks such as fiber distributed data interface (FDDI) are widely accepted and supported by the industry as one of the international standards for high-speed local area networks (LAN).Therefore, in this presentation, a novel surface-micro mac...

  9. Investigations on birefringence effects in polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Hu, Xiaolian; Saez-Rodriguez, D.

    2014-01-01

    Step-index polymer optical fiber Bragg gratings (POFBGs) and microstructured polymer optical fiber Bragg gratings (mPOFBGs) present several attractive features, especially for sensing purposes. In comparison to FBGs written in silica fibers, they are more sensitive to temperature and pressure because of the larger thermo-optic coefficient and smaller Young's modulus of polymer materials. (M)POFBGs are most often photowritten in poly(methylmethacrylate) (PMMA) materials using a continuous-wave 325 nm HeCd laser. For the first time to the best of our knowledge, we study photoinduced birefringence effects in (m)POFBGs. To achieve this, highly reflective gratings were inscribed with the phase mask technique. They were then monitored in transmission with polarized light. For this, (m)POF sections a few cm in length containing the gratings were glued to angled silica fibers. Polarization dependent loss (PDL) and differential group delay (DGD) were computed from the Jones matrix eigenanalysis using an optical vectoranalyser. Maximum values exceeding several dB and a few picoseconds were obtained for the PDL and DGD, respectively. The response to lateral force was finally investigated. As it induces birefringence in addition to the photo-induced one, an increase of the PDL and DGD values were noticed.

  10. Chronology of Fabry-Perot Interferometer Fiber-Optic Sensors and Their Applications: A Review

    Directory of Open Access Journals (Sweden)

    Md. Rajibul Islam

    2014-04-01

    Full Text Available Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed.

  11. Use of fiber optic equipment for security

    International Nuclear Information System (INIS)

    The use of fiber optic equipment in the field of security is becoming widely accepted. Great strides made in the development of splitters, couplers, multiplexers, switches, and sensors developed to expand the capabilities of the optic cable have made its application in more demand. Upgrades have provided systems with noise free video transmission in both black and white and in color. Ground loop problems have been lessened. The system using fiber optics for video transmission also transmits audio for the purpose of monitoring areas under surveillance

  12. Fourier transform optical profilometry using fiber optic Lloyd's mirrors.

    Science.gov (United States)

    Kart, Türkay; Köso?lu, Gül?en; Yüksel, Heba; ?nci, Mehmet Naci

    2014-12-10

    A fiber optic Lloyd's mirror assembly is used to obtain various optical interference patterns for the detection of 3D rigid body shapes. Two types of fiber optic Lloyd's systems are used in this work. The first consists of a single-mode optical fiber and a highly reflecting flat mirror to produce bright and dark strips. The second is constructed by locating a single-mode optical fiber in a v-groove, which is formed by two orthogonal flat mirrors to allow the generation of square-type interference patterns for the desired applications. The structured light patterns formed by these two fiber Lloyd's techniques are projected onto 3D objects. Fringe patterns are deformed due to the object's surface topography, which are captured by a digital CCD camera and processed with a Fourier transform technique to accomplish 3D surface topography of the object. It is demonstrated that the fiber-optic Lloyd's technique proposed in this work is more compact, more stable, and easier to configure than other existing surface profilometry systems, since it does not include any high-cost optical tools such as aligners, couplers, or 3D stages. The fringe patterns are observed to be more robust against environmental disturbances such as ambient temperature and vibrations. PMID:25608057

  13. 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...

  14. Fiber optic temperature profiling for thermal protection heat shields

    Science.gov (United States)

    Black, Richard J.; Costa, Joannes M.; Moslehi, Behzad; Zarnescu, Livia; Hackney, Drew; Peters, Kara

    2014-04-01

    Reliable Thermal Protection System (TPS) sensors are needed to achieve better designs for spacecraft (probe) heatshields for missions requiring atmospheric aero-capture or entry/reentry. In particular, they will allow both reduced risk and heat-shield mass minimization, which will facilitate more missions and allow increased payloads and returns. For thermal measurements, Intelligent Fiber Optic Systems Corporation (IFOS) is providing a temperature monitoring system involving innovative lightweight, EMI-immune, high-temperature resistant Fiber Bragg Grating (FBG) sensors with a thermal mass near that of TPS materials together with fast FBG sensor interrogation. The IFOS fiber optic sensing technology is highly sensitive and accurate. It is also low-cost and lends itself to high-volume production. Multiple sensing FBGs can be fabricated as arrays on a single fiber for simplified design and reduced cost. In this paper, we provide experimental results to demonstrate the temperature monitoring system using multi-sensor FBG arrays embedded in small-size Super-Light Ablator (SLA) coupon, which was thermally loaded to temperatures in the vicinity of the SLA charring temperature. In addition, a high temperature FBG array was fabricated and tested for 1000°C operation.

  15. Fiber-Optic Sensor for Aircraft Lightning Current Measurement

    Science.gov (United States)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George G.; Mata, Carlos T.; Mata, Angel G.; Snyder, Gary P.

    2012-01-01

    An electric current sensor based on Faraday rotation effect in optical fiber was developed for measuring aircraft lightning current. Compared to traditional sensors, the design has many advantages including the ability to measure total current and to conform to structure geometries. The sensor is also small, light weight, non-conducting, safe from interference, and free of hysteresis and saturation. Potential applications include characterization of lightning current waveforms, parameters and paths, and providing environmental data for aircraft certifications. In an optical fiber as the sensing medium, light polarization rotates when exposed to a magnetic field in the direction of light propagation. By forming closed fiber loops around a conductor and applying Ampere s law, measuring the total light rotation yields the enclosed current. A reflective polarimetric scheme is used, where polarization change is measured after the polarized light travels round-trip through the sensing fiber. The sensor system was evaluated measuring rocket-triggered lightning over the 2011 summer. Early results compared very well against a reference current shunt resistor, demonstrating the sensor s accuracy and feasibility in a lightning environment. While later comparisons show gradually increasing amplitude deviations for an undetermined cause, the overall waveforms still compared very well.

  16. Clinical in vivo dosimetry using optical fibers

    International Nuclear Information System (INIS)

    Purpose: To test the applicability and reliability of a recently developed optical radiation dosimetry fiber in routine radiotherapy practice. Materials and Methods: Discoloring of glass due to ionizing radiation (radiation induced optical loss) may serve as a measure of the absorbed dose. We developed a dosimeter for applications in radiation therapy based on optical fibers used for communication purposes. The silica fiber was doped with a) PbO and b) GeP. The optical fibers were investigated under various conditions in photon (LINAC x-rays, Co-60, Cs-137) and electron (LINAC) beams. The diameter of the mounted fiber is less than 1 mm, while the length depends on the sensitivity required. A fiber coil with a total length of 0.6 m forms a small disc (Oe=15mm, thicknessTM human phantom, and measurements of scattered radiation with TLD's (LiF) were performed. Both results are compared. Results: As the first clinical application of this novel optical fiber dosimeter, the scattered photon dose delivered near the eye lens was determined in vivo during orbital radiation. 8 irradiations in 4 patients were evaluated. The results were obtained simultaneously during irradiation. The scattered dose to the front of the eye bulb was 30-40 cGy per single fraction of 2 Gy. Errors in patient setup or incorrect angulation can be recognized immediately, and irradiation can be stopped. TLD (LiF) measurements under the same conditions in a AldersonTM human phantom resulted in 40 cGy scattered dose. Conclusion: Optical fibers are suitable for use in clinical dosimetry. With a fiberlength of 0.6 m scattered photon radiation in orbital irradiation can be reliably measured. The comparison with TLD measurements shows good agreement. In contrast to TLD, optical fiber radiation sensors provide immediate dose values, and the readout procedure is much easier. If the fiber is terminated by a mirror and reflected light is measured, the fiber can be used within a syringe. Thus, interesting invasive dose measurements are feasible

  17. Optical fibers and their instrumentation applications

    International Nuclear Information System (INIS)

    The use of optical fibers in instrumentation requires a knowledge of their properties as ''photon carriers'' and ''sensors''. New instrumentation design implies a satisfactory evaluation of the entire measurement circuit, including the emitter, optical coupling, optical fiber with its physical, spectral and physico-chemical properties, the connector, receiver, signal amplifier and data processing system. An example, is provided of the development of a new technique in physico-chemical instrumentation: remote spectrophotometry. Three aspects are discussed: 1) industrial measurement in ''process control'' using the Telephot (R), 2) remote spectral measurement, 3) opical multiplexing. This is followed by a review of various optical fiber based instrumental techniques used in the fields of medicine (endoscopy, fluorothermy, laser surgery), solar energy industrial applications subject to electrical disturbances (position sensors, strain measurements), and in physico-chemical analysis (fluorescence, redox potentials)

  18. Radiation resistant characteristics of optical fiber, 4

    International Nuclear Information System (INIS)

    A modified GI type optical fiber, the core of which was doped with boron and fluorine, was fabricated for trial to improve defects of limitation of employable wavelengths for transmission, which were usually found in the SI-type OP fibers, the core of which were made OT pure quartz fiber. This report describes results of radiation resistivity characteristics of the modified GI type optical fiber at the standpoint of practicability. Experimental work was carried out for continuous measurement of light transmission characterics and of wavelength dependency of light transmission loss during ?-ray irradiation from 60Co ?-ray source, Results by employing the test specimen of the modified GI type optical fiber made by the MCVD method showed several advantages in comparison with a conventional GI-type optical fiber doped with Ge and P. The modified GI type fiber had a better radiation dose rate effect, photobleaching effect and restoration capability after irradiation. Formation of color center was accelerated by shorter wavelength rays and it was found more suitable to employ light of 1.3 ?m of longer wavelength 0.85 ?m of the conventionally employed rays. Transmission loss increase by 1 MR irradiation was 100 dB/km and 250 dB/km for 65 MR. The latter value was restored to 100 dB/km after 30 hours of irradiation, and it was concluded that the radiation resistivity was significantly improved. It should be improved, however, that transmission loss is still higher of one order in the modified GI type fiber than the modified SI type fiber. (Takagi, S.)

  19. Processing of optical combs with fiber optic parametric amplifiers.

    Czech Academy of Sciences Publication Activity Database

    Slavík, Radan; Kakande, J.; Richardson, D.J.; Petropoulos, P.

    2012-01-01

    Ro?. 20, ?. 9 (2012), s. 10059-10070. ISSN 1094-4087 Institutional support: RVO:67985882 Keywords : Fiber-optic parametric amplifier * Phase sensitive * Spectral coverage Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.546, year: 2012

  20. Optical Fiber Specifications For Long Term Maintenance

    Science.gov (United States)

    Skutnik, Bolesh J.

    1990-01-01

    In recent years the reliability of optical fibers in special environments has become of great concern in military, government and other specialty high performance applications. With the first exploratory installations of fiber-to-the-home confirming the inherent requirements for a robust optical fiber, the telecommunications market and operating companies have had to begin considering how to minimize long term maintenance of optical fiber systems, which are subjected to a much broader range of dangers than in long haul or station to station installations. This paper discusses some background information on the strength and fatigue of optical fibers/cables, their reliability issues and several points concerning design and lifetime predictions for such components/systems. It includes information on standards efforts in fiber reliability and environmental testing as well as on SPIE efforts to present up-to-date information on these topic areas. Its intent is to point out problem areas for long term maintenance and present current approaches to minimize these problems rather than present solutions.

  1. Photogrammetric Verification of Fiber Optic Shape Sensors on Flexible Aerospace Structures

    Science.gov (United States)

    Moore, Jason P.; Rogge, Matthew D.; Jones, Thomas W.

    2012-01-01

    Multi-core fiber (MCF) optic shape sensing offers the possibility of providing in-flight shape measurements of highly flexible aerospace structures and control surfaces for such purposes as gust load alleviation, flutter suppression, general flight control and structural health monitoring. Photogrammetric measurements of surface mounted MCF shape sensing cable can be used to quantify the MCF installation path and verify measurement methods.

  2. Polymeric Optical Fibres for Biomedical Sensing

    OpenAIRE

    Krehel, M P

    2014-01-01

    In this thesis we focus on the integration of optical fibres in textiles to create wearable sensing systems. In the introduction (Chapter 3) we describe the basics of light guiding in optical fibres and methods of lateral light coupling. Subsequently, a literature review and motivation are presented. Afterwards two main parts can be differentiated. In the first one (Chapters 4, 5) a new method of continuous extrusion of optical fibres and their medical sensing application using photoplethysmo...

  3. Response Characterization of a Fiber Optic Sensor Array with Dye-Coated Planar Waveguide for Detection of Volatile Organic Compounds

    OpenAIRE

    Jae-Sung Lee; Na-Rae Yoon; Byoung-Ho Kang; Sang-Won Lee; Sai-Anand Gopalan; Hyun-Min Jeong; Seung-Ha Lee; Dae-Hyuk Kwon; Shin-Won Kang

    2014-01-01

    We have developed a multi-array side-polished optical-fiber gas sensor for the detection of volatile organic compound (VOC) gases. The side-polished optical-fiber coupled with a polymer planar waveguide (PWG) provides high sensitivity to alterations in refractive index. The PWG was fabricated by coating a solvatochromic dye with poly(vinylpyrrolidone). To confirm the effectiveness of the sensor, five different sensing membranes were fabricated by coating the side-polished optical-fiber us...

  4. Towards biochips using microstructured optical fiber sensors

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Hoiby, Poul Erik; Jensen, Jesper Bo; Pedersen, Lars Hagsholm; Bang, Ole; Geschke, Oliver

    2006-01-01

    In this paper we present the first incorporation of a microstructured optical fiber (MOF) into biochip applications. A 16-mm-long piece of MOF is incorporated into an optic-fluidic coupler chip, which is fabricated in PMMA polymer using a CO2 laser. The developed chip configuration allows the continuous control of liquid flow through the MOF and simultaneous optical characterization. While integrated in the chip, the MOF is functionalized towards the capture of a specific single-stranded DNA str...

  5. Fiber Optic Strain Sensor for Planetary Gear Diagnostics

    Science.gov (United States)

    Kiddy, Jason S.; Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason

    2011-01-01

    This paper presents a new sensing approach for helicopter damage detection in the planetary stage of a helicopter transmission based on a fiber optic strain sensor array. Complete helicopter transmission damage detection has proven itself a difficult task due to the complex geometry of the planetary reduction stage. The crowded and complex nature of the gearbox interior does not allow for attachment of sensors within the rotating frame. Hence, traditional vibration-based diagnostics are instead based on measurements from externally mounted sensors, typically accelerometers, fixed to the gearbox exterior. However, this type of sensor is susceptible to a number of external disturbances that can corrupt the data, leading to false positives or missed detection of potentially catastrophic faults. Fiber optic strain sensors represent an appealing alternative to the accelerometer. Their small size and multiplexibility allows for potentially greater sensing resolution and accuracy, as well as redundancy, when employed as an array of sensors. The work presented in this paper is focused on the detection of gear damage in the planetary stage of a helicopter transmission using a fiber optic strain sensor band. The sensor band includes an array of 13 strain sensors, and is mounted on the ring gear of a Bell Helicopter OH-58C transmission. Data collected from the sensor array is compared to accelerometer data, and the damage detection results are presented

  6. ArF excimer laser microprocessing of polymer optical fibers for photonic sensor applications

    International Nuclear Information System (INIS)

    A study of polymer optical fiber microstructuring by use of deep ultraviolet excimer laser radiation at 193 nm wavelength is performed. The ablation characteristics of the fiber cladding and core materials are analyzed comparatively. The laser irradiation effects are dynamically studied by on-line monitoring of the laser ablation induced waveguiding losses, the latter being correlated with the spatial structuring parameters. The fiber surface is modified to incorporate cavities, which are subsequently employed as sensitive material receptors for the development of customized photonic sensors. The sensing capability of the microstructured plastic optical fibers is demonstrated by ammonia and humidity detection. (paper)

  7. The performance limit of ?-OTDR sensing system enhanced with ultra-weak fiber Bragg grating array

    Science.gov (United States)

    Xia, Lan; Zhang, Yixin; Zhu, Fan; Cao, Chunqi; Zhang, Xuping

    2015-08-01

    Phase sensitive optical time domain reflectometry (?-OTDR) has been widely used in various applications for its distributed measurement capability of dynamic disturbance along the entire length of sensing fiber. In our previous research, the capacity of ?-OTDR sensing system has been enhanced with ultra-weak fiber Bragg grating (UWFBG) array for high-precision quantitative measurement on the external disturbance. Multipoint n? level dynamic strain variation has been fully captured with 2m spatial resolution. However, only 5 identical UWFBGs were used in the demonstration. For large-scale sensing network, the detectable fiber length would be limited by the signal-to-noise ratio (SNR) and the dynamic range of the reflection signal. In this paper, the performance limit of the UWFGB array enhanced ?-OTDR sensing system has been investigated. A numerical simulation was performed to illustrate the relationships between the SNR, sensing length, spatial resolution and the UWFBG reflectivity. The simulation results have shown that when the reflectivity is relatively low, the noise is mainly contributed from Rayleigh scattering. On the other hand, the multiple reflections will dominate the overall noise characteristic with the growing of UWFBG reflectivity. The requirement of detection dynamic range was also analyzed. Simulation has shown that lower UWFBG reflectivity will lead to smaller signal dynamic range, making the selection of detector more practicable. The analysis result is quite useful for designing large-scale sensing network based on UWFGB array enhanced ?-OTDR sensing system in practical situation.

  8. Impact of nonlinearities on fiber optic communications

    CERN Document Server

    2011-01-01

    This book covers the recent progress in fiber-optic communication systems with a main focus on the impact of fiber nonlinearities on system performance. There has been significant progress in coherent communication systems in the past few years due to the advances in digital signal processing techniques. This has led to renewed interest in fiber linear and nonlinear impairments as well as techniques to mitigate them in the electrical domain. In this book, the reader will find all the important topics of fiber optic communication systems in one place, with in-depth coverage by the experts of each sub-topic. Pioneers from each of the sub-topics have been invited to contribute. Each chapter will have a section on fundamentals as well as reviews of literature and of recent developments. Readers will benefit from this approach since many of the conference proceedings and journal articles mainly focus on the authors’ research, without spending space on preliminaries.

  9. An Integrated Photoluminescence Sensing Platform Using a Single-Multi-Mode Fiber Coupler-Based Probe

    Directory of Open Access Journals (Sweden)

    Feng Long

    2014-03-01

    Full Text Available We demonstrate an integrated fiber optic photoluminescence sensing platform using a novel single-multi-mode fiber coupler (SMFC-based probe with high collection efficiency for fluorescence signals. The SMFC, prepared using fused biconical taper technology, not only transmits excitation light, but also collects and transmits fluorescence. The entire system does not use complex optical components and rarely requires optical alignment. The simple structure of the SMFC considerably improves the light transmission efficiency, signal-to-noise ratio, and sensitivity of the system. Theoretical and experimental results show that the proposed probe increases the collection efficiency by more than eight-fold compared with a bifurcated fiber probe. The performance of the proposed probe was experimentally evaluated by measuring the fluorescence spectra of well-known targets and a fresh Tall Fescue leaf.

  10. Evaluations of fiber optic sensors for interior applications

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, M.W.; Malone, T.P.

    1996-02-01

    This report addresses the testing and evaluation of commercial fiber optic intrusion detection systems in interior applications. The applications include laying optical fiber cable above suspended ceilings to detect removal of ceiling tiles, embedding optical fibers inside a tamper or item monitoring blanket that could be placed over an asset, and installing optical fibers on a door to detect movement or penetration. Detection capability of the fiber optic sensors as well as nuisance and false alarm information were focused on during the evaluation. Fiber optic sensor processing, system components, and system setup are described.

  11. Fiber Optics Communication In Computer Networking And Security

    OpenAIRE

    De, Soumya; Shivangi Singh

    2014-01-01

    Fiber Optics Communication is a branch of optical communication which is widely used now-a-days in communication world. Due to many advantages of fiber optics communication over different conventional communication method it is having higher priority. Today there is hardly any communication field where fiber optics has not left its mark.

  12. Strain measurement using multiplexed fiber optic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Il Bum; Kim, Chi Yeop; Yoon, Dong Jin; Lee, Seung Seok [Smart Measurment Group. Korea Resarch Institute of Standards and Science, Saejeon (Korea, Republic of)

    2003-05-15

    FBG(Fiber Bragg grating) sensor, which is one of the fiber optic sensors for the application of smart structures, can not only measure one specific point but also multiple points by multiplexing techniques. We have proposed a novel multiplexing technique of FBG sensor by the intensity modulation of light source. This technique is applicable to WDM(Wavelength Division Multiplexing) technique and number of sensors in this system can be increased by using this technique with WDM technique.

  13. Propagation mechanism of polymer optical fiber fuse

    OpenAIRE

    Yosuke Mizuno; Neisei Hayashi; Hiroki Tanaka; Kentaro Nakamura; Shin-ichi Todoroki

    2014-01-01

    A fiber fuse phenomenon in polymer optical fibers (POFs) has recently been observed, and its unique properties such as slow propagation, low threshold power density, and the formation of a black oscillatory damage curve, have been reported. However, its characterization is still insufficient to well understand the mechanism and to avoid the destruction of POFs. Here, we present detailed experimental and theoretical analyses of the POF fuse propagation. First, we clarify that the bright spot i...

  14. Nonlinear soliton matching between optical fibers

    DEFF Research Database (Denmark)

    Agger, Christian; Sørensen, Simon Toft; Thomsen, Carsten L.; Keiding, Søren R.; Bang, Ole

    2011-01-01

    In this Letter, we propose a generic nonlinear coupling coefficient, ?2 NL ¼ ?j?=?2jfiber2=j?=?2jfiber1, which gives a quantitative measure for the efficiency of nonlinear matching of optical fibers by describing how a fundamental soliton couples from one fiber into another. Specifically, we use ?NL to demonstrate a significant soliton selffrequency shift of a fundamental soliton, and we show that nonlinear matching can take precedence over linear mode matching. The nonlinear coupling coefficien...

  15. Fiber optically isolated and remotely stabilized data transmission system

    Science.gov (United States)

    Nelson, Melvin A. (Santa Barbara, CA)

    1992-01-01

    A fiber optically isolated and remotely stabilized data transmission system s described wherein optical data may be transmitted over an optical data fiber from a remote source which includes a data transmitter and a power supply at the remote source. The transmitter may be remotely calibrated and stabilized via an optical control fiber, and the power source may be remotely cycled between duty and standby modes via an optical control fiber.

  16. A Special Fiber Optic Sensor for Measuring Wheel Loads of Vehicles on Highways

    Directory of Open Access Journals (Sweden)

    Norman W. Garrick

    2008-04-01

    Full Text Available This paper presents results from an investigation on a special optical fiber as a load sensor for application in Weigh-in-Motion (WIM systems to measure wheel loads of vehicles traveling at normal speed on highways. The fiber used has a unique design with two concentric light guiding regions of different effective optical path lengths, which has the potential to enable direct measurement of magnitudes as well as locations of forces acting at multiple points along a single fiber. The optical characteristic of the fiber for intended sensing purpose was first assessed by a simple fiber bending experiment and by correlating the bend radii with the output light signal intensities. A simple laboratory load transmitting/fiber bending device was then designed and fabricated to appropriately bend the optical fiber under applied loads in order to make the fiber work as load sensor. The device with the optical fiber was tested under a universal loading machine and an actual vehicle wheel in the laboratory. The test results showed a good relationship between the magnitude of the applied load and the output optical signal changes. The results also showed a good correlation between the time delay between the inner and outer core light pulses and the distance of the applied load as measured from the output end of the fiber.

  17. ANALYSIS OF OPTICAL FIBER COMMUNICATION SYSTEM USING FREE-SPACE FIBER OPTIC SWITCHES

    Directory of Open Access Journals (Sweden)

    Ashutosh Kumar

    2014-06-01

    Full Text Available Optical fiber offers many advantages compared with electric cables, including high bandwidth, low loss, and lightweight, immunity from lightening strikes and the resultant current surges, and no electromagnetic interference. Fiber optic networks such as fiber distributed data interface (FDDI are widely accepted and supported by the industry as one of the international standards for high-speed local area networks (LAN.Therefore, in this presentation, a novel surface-micro machined free- space fiber optic switch with integrated microactuators for optical fiber communication systems has been presented. The free operation up to 89 g’s has been achieved for vibration frequencies from 200 Hz to 10 kHz.

  18. Focusing over Optical Fiber Using Time Reversal

    DEFF Research Database (Denmark)

    Piels, Molly; Porto da Silva, Edson

    2015-01-01

    A time-reversal array in multimode fiber is proposed for lossless remotely controlled switching using passive optical splitters. The signal to be transmitted is digitally pre-distorted so that it is routed through the physical layer in order to arrive at only one receiver in an array. System performance in the presence of additive white gaussian noise, modal group delay, and timing error is investigated numerically for single-mode and 10-mode fiber. Focusing using a two-transmitter array and 44 km of single- mode fiber is demonstrated experimentally for 3 GBd QPSK signals with a bit error rate below the forward error correction limit.

  19. Optical fibers with gradient index nanostructured core.

    Science.gov (United States)

    Buczy?ski, Ryszard; Klimczak, Mariusz; Stefaniuk, Tomasz; Kasztelanic, Rafa?; Siwicki, Bart?omiej; St?pniewski, Grzegorz; Cimek, Jaros?aw; Pysz, Dariusz; St?pie?, Ryszard

    2015-10-01

    We present a new approach for the development of structured optical fibers. It is shown that fibers having an effective gradient index profile with designed refractive index distribution can be developed with internal nanostructuring of the core composed of two glasses. As proof-of-concept, fibers made of two soft glasses with a parabolic gradient index profile are developed. Energy-dispersive X-ray spectroscopy reveals a possibility of selective diffusion of individual chemical ingredients among the sub-wavelength components of the nanostructure. This hints a postulate that core nanostructuring also changes material dispersion of the glasses in the core, potentially opening up unique dispersion shaping possibilities. PMID:26480075

  20. Study of fiber optic sugar sensor

    Indian Academy of Sciences (India)

    A Jayanth Kumar; N M Gowri; R Venkateswara Raju; G Nirmala; B S Bellubbi; T Radha Krishna

    2006-08-01

    Over the last two decades, the fiber optic technology has passed through many analytical stages. Some commercially available fiber optic sensors, though in a small way, are being used for automation in mechanical and industrial environments. They are also used for instrumentation and controls. In the present work, an intensity-modulated intrinsic fiber optic sugar sensor is presented. This type of sensor, with slight modification, can be used for on-line determination of the concentration of sugar content in sugarcane juice in sugar industry. In the present set-up, a plastic fiber made of polymethylmethacrylate is used. A portion of the cladding (1 cm, 2 cm, 3 cm) at the mid-point along the length of the fiber is removed. This portion is immersed in sugar solution of known concentration and refractive index. At one end of the fiber an 850 nm source is used and at the other end a power meter is connected. By varying the concentration of sugar solution, the output power is noted. These studies are made due to the change in refractive index of the fluid. The device was found to be very sensitive which is free from EMI and shock hazards, stable and repeatable and they can be remotely interfaced with a computer to give on-line measurements and thus become useful for application in sugar industries.

  1. Fiber optic probe for light scattering measurements

    Science.gov (United States)

    Nave, S.E.; Livingston, R.R.; Prather, W.S.

    1993-01-01

    This invention is comprised of a fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman- scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.

  2. Hot Springs-Garrison Fiber Optic Project

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Bonneville Power Administration (BPA) is proposing to upgrade its operational telecommunications system between the Hot Springs Substation and the Garrison Substation using a fiber optic system. The project would primarily involve installing 190 kilometers (120 miles) of fiber optic cable on existing transmission structures and installing new fiber optic equipment in BPA`s substation yards and control houses. BPA prepared an environmental assessment (EA) evaluating the proposed action. This EA was published in October 1994. The EA identifies a number of minor impacts that might occur as a result of the proposed action, as well as some recommended mitigation measures. This Mitigation Action Plan (MAP) identifies specific measures to avoid, minimize, or compensate for impacts identified in the EA.

  3. Stabilized Optical Fiber Links for the XFEL

    CERN Document Server

    Winter, Axel; Grawert, Felix J; Ilday, Fatih O; Kaertner, Franz X; Kim, Jung-Won; Schlarb, Holger; Schmidt, Bernhard

    2005-01-01

    The timing synchronization scheme for the European X-Ray free electron laser facility (XFEL) is based on the generation and distribution of sub-picosecond laser pulses with actively stabilized repetition rate which are used to synchronize local RF oscillators. An integral part of the scheme is the distribution of the optical pulse stream to parts of the facility via optical fiber links. The optical path length of the fiber has to be stabilized against short-term and long-term timing jitter due to environmental effects, such as temperature drifts and acoustic vibrations, to better than 10 fs for distances ranging from tens of meters to several kilometers. In this paper, we present first experimental results for signal transmission through a km-long fiber link with femtosecond stability.

  4. Quantum cryptography over underground optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, R.J.; Luther, G.G.; Morgan, G.L.; Peterson, C.G.; Simmons, C.

    1996-05-01

    Quantum cryptography is an emerging technology in which two parties may simultaneously generated shared, secret cryptographic key material using the transmission of quantum states of light whose security is based on the inviolability of the laws of quantum mechanics. An adversary can neither successfully tap the key transmissions, nor evade detection, owing to Heisenberg`s uncertainty principle. In this paper the authors describe the theory of quantum cryptography, and the most recent results from their experimental system with which they are generating key material over 14-km of underground optical fiber. These results show that optical-fiber based quantum cryptography could allow secure, real-time key generation over ``open`` multi-km node-to-node optical fiber communications links between secure ``islands.``

  5. Hot Springs-Garrison Fiber Optic Project

    International Nuclear Information System (INIS)

    Bonneville Power Administration (BPA) is proposing to upgrade its operational telecommunications system between the Hot Springs Substation and the Garrison Substation using a fiber optic system. The project would primarily involve installing 190 kilometers (120 miles) of fiber optic cable on existing transmission structures and installing new fiber optic equipment in BPA's substation yards and control houses. BPA prepared an environmental assessment (EA) evaluating the proposed action. This EA was published in October 1994. The EA identifies a number of minor impacts that might occur as a result of the proposed action, as well as some recommended mitigation measures. This Mitigation Action Plan (MAP) identifies specific measures to avoid, minimize, or compensate for impacts identified in the EA

  6. Liquid crystalline fiber optic colorimeter for hydrostatic pressure measurement

    Science.gov (United States)

    Wolinski, Tomasz R.; Bajdecki, Waldemar K.; Domanski, Andrzej W.; Karpierz, Miroslaw A.; Konopka, Witold; Nasilowski, T.; Sierakowski, Marek W.; Swillo, Marcin; Dabrowski, Roman S.; Nowinowski-Kruszelnicki, Edward; Wasowski, Janusz

    2001-08-01

    This paper presents results of tests performed on a fiber optic system of liquid crystalline transducer for hydrostatic pressure monitoring based on properties of colorimetry. The system employs pressure-induced deformations occurring in liquid crystalline (LC) cells configured in a homogeneous Frederiks geometry. The sensor is compared of a round LC cell placed inside a specially designed pressure chamber. As a light source we used a typical diode operating at red wavelength and modulated using standard techniques. The pressure transducer was connected to a computer with a specially designed interface built on the bas of advanced ADAM modules. Results indicate that the system offers high response to pressure with reduced temperature sensitivity and, depending on the LC cell used, can be adjusted for monitoring of low hydrostatic pressures up to 6 MPa. These studies have demonstrated the feasibility of fiber optic liquid crystal colorimeter for hydrostatic pressure sensing specially dedicated to pipe- lines, mining instrumentation, and process-control technologies.

  7. Temperature sensing based on a Brillouin fiber microwave generator

    International Nuclear Information System (INIS)

    We propose and demonstrate a novel dual-frequency Brillouin fiber laser used for microwave generation. Based on this configuration, temperature sensing has been realized. The dual-frequency Brillouin lasing is generated independently from two pieces of fiber cascaded within one ring resonator. Microwave generation is acquired as the beat signal of the dual-frequency Brillouin fiber laser, with the beat frequency being linearly proportional to the temperature difference of the two fiber sections. In the experiment, the temperature coefficient of frequency shift is 1.015 ± 0.001 MHz °C?1. The temperature can be precisely measured by acquiring the frequency of the microwave generator, and this new configuration provides a promising application for temperature sensing. (paper)

  8. Parametric Study of the Reflective Periodic Grating for In-Plane Displacement Measurement Using Optical Fibers

    OpenAIRE

    Chun-Gon Kim; Dae-Hyun Kim; Yeon-Gwan Lee

    2012-01-01

    This paper presents a technique for a simple sensing principle that can be used for the measurement of displacement. The proposed sensor head is composed of a reflective grating panel and an optical fiber as a transceiver. The simplified layout contributes to resolving the issues of space restraints during installation and complex cabling problems in transmission fiber optic sensors. In order to verify the effectiveness of the proposed technique, it is important to obtain the sinusoidal signa...

  9. An optical fiber sensor for the detection and monitoring of cracks in reinforced concrete structures

    OpenAIRE

    Benard, Abraham Diaz de León

    2007-01-01

    Advances in the emerging fiber optic sensing technology have contributed to the recent development of innovative systems for health monitoring of civil engineering structures. The main reasons for this development are the reduced weight and dimensions of fiber optic sensors, the strong immunity to electromagnetic interference, the improved environmental resistance and the scale flexibility for small-gage and long-gage measurements. Researchers at the Massachusetts Institute of Technology and ...

  10. Fiber Optic Chemical Nanosensors Based on Engineered Single-Walled Carbon Nanotubes

    OpenAIRE

    A. Cusano; Giordano, M.; Aversa, P.; M. Penza; A. Cutolo; M. Consales

    2008-01-01

    In this contribution, a review of the development of high-performance optochemical nanosensors based on the integration of carbon nanotubes with the optical fiber technology is presented. The paper first provide an overview of the amazing features of carbon nanotubes and their exploitation as highly adsorbent nanoscale materials for gas sensing applications. Successively, the attention is focused on the operating principle, fabrication, and characterization of fiber optic chemosensors...

  11. Concentric core optical fiber with multiple-mode signal transmission

    Science.gov (United States)

    Muhs, Jeffrey D. (Lenoir City, TN)

    1997-01-01

    A concentric core optical fiber provides for the simultaneous but independent transmission of signals over a single optical fiber. The concentric optical fiber is constructed of a single-mode or multimode inner optical fiber defined by a core and a cladding of a lower index of refraction than the core and an outer optical fiber defined by additional cladding concentrically disposed around the cladding and of an index of refraction lower than the first mentioned cladding whereby the latter functions as the core of the outer optical fiber. By employing such an optical fiber construction with a single-mode inner core or optical fiber, highly sensitive interferometric and stable less sensitive amplitude based sensors can be placed along the same length of a concentric core optical fiber. Also, by employing the concentric core optical fiber secure telecommunications can be achieved via the inner optical fiber since an intrusion of the concentric optical fiber will first cause a variation in the light being transmitted through the outer optical fiber and this variation of light being used to trigger a suitable alarm indicative of the intrusion.

  12. Development and evaluation of optical fiber NH3 sensors for application in air quality monitoring

    Science.gov (United States)

    Huang, Yu; Wieck, Lucas; Tao, Shiquan

    2013-02-01

    Ammonia is a major air pollutant emitted from agricultural practices. Sources of ammonia include manure from animal feeding operations and fertilizer from cropping systems. Sensor technologies with capability of continuous real time monitoring of ammonia concentration in air are needed to qualify ammonia emissions from agricultural activities and further evaluate human and animal health effects, study ammonia environmental chemistry, and provide baseline data for air quality standard. We have developed fiber optic ammonia sensors using different sensing reagents and different polymers for immobilizing sensing reagents. The reversible fiber optic sensors have detection limits down to low ppbv levels. The response time of these sensors ranges from seconds to tens minutes depending on transducer design. In this paper, we report our results in the development and evaluation of fiber optic sensor technologies for air quality monitoring. The effect of change of temperature, humidity and carbon dioxide concentration on fiber optic ammonia sensors has been investigated. Carbon dioxide in air was found not interfere the fiber optic sensors for monitoring NH3. However, the change of humidity can cause interferences to some fiber optic NH3 sensors depending on the sensor's transducer design. The sensitivity of fiber optic NH3 sensors was found depends on temperature. Methods and techniques for eliminating these interferences have been proposed.

  13. Dynamic Strain Measured by Mach-Zehnder Interferometric Optical Fiber Sensors

    Directory of Open Access Journals (Sweden)

    Shiuh-Chuan Her

    2012-03-01

    Full Text Available Optical fibers possess many advantages such as small size, light weight and immunity to electro-magnetic interference that meet the sensing requirements to a large extent. In this investigation, a Mach-Zehnder interferometric optical fiber sensor is used to measure the dynamic strain of a vibrating cantilever beam. A 3 × 3 coupler is employed to demodulate the phase shift of the Mach-Zehnder interferometer. The dynamic strain of a cantilever beam subjected to base excitation is determined by the optical fiber sensor. The experimental results are validated with the strain gauge.

  14. Optical Fiber LSPR Biosensor Prepared by Gold Nanoparticle Assembly on Polyelectrolyte Multilayer

    Directory of Open Access Journals (Sweden)

    Yunliang Shao

    2010-04-01

    Full Text Available This article provides a novel method of constructing an optical fiber localized surface plasmon resonance (LSPR biosensor. A gold nanoparticle (NP assembled film as the sensing layer was built on the polyelectrolyte (PE multilayer modified sidewall of an unclad optical fiber. By using a trilayer PE structure, we obtained a monodisperse gold NP assembled film. The preparation procedure for this LSPR sensor is simple and time saving. The optical fiber LSPR sensor has higher sensitivity and outstanding reproducibility. The higher anti-interference ability for response to an antibody makes it a promising method in application as a portable immuno-sensor.

  15. Lasers and optical fibers in medicine

    CERN Document Server

    Katzir, Abraham

    1993-01-01

    The increasing use of fiber optics in the field of medicine has created a need for an interdisciplinary perspective of the technology and methods for physicians as well as engineers and biophysicists. This book presents a comprehensive examination of lasers and optical fibers in an hierarchical, three-tier system. Each chapter is divided into three basic sections: the Fundamentals section provides an overview of basic concepts and background; the Principles section offers an in-depth engineering approach; and the Advances section features specific information on systems an

  16. Infrared study of ? irradiated fluoride optical fibers

    International Nuclear Information System (INIS)

    In order to develop infrared optical fiber systems in nuclear media, studies are made to know the behavior on line of fluoride glass optical fibers under irradiation. The increase of induced loss and the influence of the dose rate are given at 2.4 microns. Cycles of relaxation at room temperature and ? ray exposure allows an important bleaching and an unaffected kinetic of losses. Characterization of defects created by ? radiation on bulk of ZBLA glass is carried out by means of electron spin resonance (ESR). A linear kinetic of ESR signal with dose is observed and possible models for defects are discussed

  17. Multiplex fiber-optic biosensor using multiple particle plasmon resonances

    Science.gov (United States)

    Lin, Hsing-Ying; Huang, Chen-Han; Liu, Yu-Chia; Huang, Kuo-Wei; Chau, Lai-Kwan

    2012-02-01

    Multiplex fiber-optic biosensor implemented by integrating multiple particle plasmon resonances (PPRs), molecular bioassays, and microfluidics is successfully demonstrated. The multiple PPRs are achieved by chemical immobilization of silver nanoparticles (AgNPs) and gold nanorods (AuNRs) separately on two unclad portions of an optical fiber. The difference in morphology and nature of material of AgNPs and AuNRs are exploited to yield multiple plasmonic absorptions at 405 and 780 nm in the absorption spectrum measured from optical fiber by white light source illumination. Through the coaxial excitation of light-emitting diodes (LEDs) with 405 and 800 nm wavelengths, the distinct PPRs are advantageous for real-time and simultaneous detection of multiple analyte-probe pairs as AgNPs and AuNRs are separately functionalized with specific bio-probes. Here, the multi-window fiber-optic particle plasmon resonance (FO-PPR) biosensor has been shown to be capable of simultaneously detecting anti-dinitrophenyl antibody (anti-DNP, MW = 220 kDa) via N-(2,4-dinitrophenyl)-6-aminohexanoic acid (DNP, MW = 297.27 Da) functionalized AgNPs and streptavidin (MW = 75 kDa) via N-(3-aminopropyl)biotinamide trifluoroacetate (biotin, MW = 414.44 Da) functionalized AuNRs. The multiplex sensing chip possesses several advantages, including rapid and parallel detection of multiple analytes on a single chip, minimized sample to sample variation, reduced amount of sensor chip, and reduced analyte volume, hence it is ideally suitable for high-throughput multiplex biochemical sensing applications.

  18. Fiber optic well monitoring system

    International Nuclear Information System (INIS)

    This paper reports on Alcatel Kabel in Norway which is developing a downwell monitoring system for permanent installations, based on optical excitation and interrogation of micromachined resonant sensors. The optical measuring concept, integrated with fibre optic communication and in combination with silicon material properties, provide unique sensor system performance, which can meet the requirements of downwell monitoring. The key components have been developed and comprises; sensor and sensor housing, fibre optic cable, fibre optic cable splices, fibre optic wet mateable connector, and optoelectronic equipment for system operation. The components have been fully characterized and tested in an onshore test well. The test results verify the inherent advantages of optical technology and demonstrate the system's high reliability potential and ability to function in high temperature applications

  19. Optically powered active sensing system for Internet Of Things

    Science.gov (United States)

    Gao, Chen; Wang, Jin; Yin, Long; Yang, Jing; Jiang, Jian; Wan, Hongdan

    2014-10-01

    Internet Of Things (IOT) drives a significant increase in the extent and type of sensing technology and equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such sensing systems will all require to be powered. Conventionally, electrical powering is supplied by batteries or/and electric power cables. The power supply by batteries usually has a limited lifetime, while the electric power cables are susceptible to electromagnetic interference. In fact, the electromagnetic interference is the key issue limiting the power supply in the strong electromagnetic radiation area and other extreme environments. The novel alternative method of power supply is power over fiber (PoF) technique. As fibers are used as power supply lines instead, the delivery of the power is inherently immune to electromagnetic radiation, and avoids cumbersome shielding of power lines. Such a safer power supply mode would be a promising candidate for applications in IOT. In this work, we built up optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we proposed a novel maximum power point tracking technique for photovoltaic power convertors. In our system, the actual output efficiency greater than 40% within 1W laser power. After 1km fiber transmission and opto-electric power conversion, a stable electric power of 210mW was obtained, which is sufficient for operating an active sensing system.

  20. Thin aerogel layers coated on silica optical fibers and their interaction with gases and liquids as a functional basis for chemical sensing.

    Czech Academy of Sciences Publication Activity Database

    Mat?jec, Vlastimil; Chomát, Miroslav; Hayer, Miloš

    1999-01-01

    Ro?. 7, ?. 2 (1999), s. 61-64. [Chinese-Czech Symposium Advanced Materials and Devices for Optoelectronics /2./. Beijing, 13.09.1999-14.09.1999] R&D Projects: GA ?R GA102/98/1358 Institutional research plan: CEZ:AV0Z2067918 Keywords : optical sensors * optical fibres Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering