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1

Optical fiber rotation sensing  

CERN Document Server

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

Burns, William K; Kelley, Paul

1993-01-01

2

Humidity sensing using plastic optical fibers  

Science.gov (United States)

A low cost, low complexity fiber optic humidity sensor is very desirable because of the various advantages fiber optic sensors have over conventional electrical sensors. In this paper a simple, low cost plastic optical fiber (POF) sensor based on cobalt chloride (CoCl2) and gelatin coating on the curved sensing point with a humidity sensing range from 60% to 95%RH is presented. An investigation into the effect of bending radii of the fiber at the sensing point as well as fiber core diameter on sensitivity of the humidity sensor is conducted to find the best way to improve sensing performance. The sensing mechanism of the POF humidity sensor is the attenuation of the evanescent wave at the bent portion of the fiber by absorption due to CoCl2. The sensor has a sensing range from 60%RH to 95%RH. The hysteresis error is negligible and a resolution of 0.01%RH is achieved. The repeatability error can be as low as 1.1% for the whole sensing range. Investigation of the effect of fiber diameter shows that the sensitivity of the sensor improves with larger fiber diameters. The sensitivity of the sensor increases when the sensing portion of the fiber is bent to a small radius.

Tay, Chia M.; Tan, Khay M.; Tjin, Swee C.; Chan, Chi Chiu; Rahardjo, Harianto

2004-12-01

3

Optical fiber chemical sensing networks  

International Nuclear Information System (INIS)

[en] Many industrial processes or other phenomena of interest cannot be measured with conventional instruments because they are too hot, too cold, highly radioactive, or otherwise inaccessible to direct observation. Nuclear wastes stored in underground repositories, for example, will require in-situ monitoring. A new technology that uses long distance fiber optics to transmit laser-excited fluorescence now makes it possible to remotely monitor such installations via optical fiber cables at distances up to one kilometer. The applications include: Sampling of remote locations; Multipoint sampling with single instrument; Measurements in inaccessible locations; Coping with aggressive environments; Avoiding contamination; and Continuous monitoring

1987-01-01

4

Instrumentation for remote sensing over fiber optics  

International Nuclear Information System (INIS)

[en] The authors developed a way to extend the sensing and analytical abilities of the laser fluorescence spectrometer beyond the physical confines of the laboratory by means of communications-grade optical fibers. These fiber probes are extremely rugged, compared with sensitive laboratory equipment, and also extremely inexpensive. They make it possible to perform sensitive chemical analyses in hostile environments without risking damage to the laser and the spectrometer. They have begun development of a remote analyzer for monitoring rare-earth-ion migration in a nuclear-waste repository, an environment too hostile for any previous remote sensing device. They are also developing optrodes sensitive to a wide variety of non-chemical stimuli

1984-01-01

5

Radiation distribution sensing with normal optical fiber  

International Nuclear Information System (INIS)

The purpose of this study is to develop a radiation distribution monitor using a normal plastic optical fiber. The monitor has a long operating length (10m-100m) and can obtain continuous radiation distributions. A principle of the position sensing is based on a time-of-flight technique. The characteristics of this monitor to beta particles, gamma rays and fast neutrons were obtained. The spatial resolutions for beta particles (90Sr-90Y), gamma rays (137Cs) and D-T neutrons were 30 cm, 37 cm and 13 cm, respectively. The detection efficiencies for the beta rays, the gamma rays and D-T neutrons were 0.11%, 1.6x10-5% and 5.4x10-4%, respectively. The effective attenuation length of the detection efficiency was 18m. New principle of the position sensing based on spectroscopic analysis was also proposed. A preliminary test showed that the spectrum observed at the end of the fiber depended on the position of the irradiated point. This fact shows that the radiation distributions were calculated from the spectrum by mathematical deconvolution technique. (author)

2002-01-01

6

Fiber optic pressure sensing with conforming elastomers.  

Science.gov (United States)

A novel pressure sensing scheme based on the effect of a conforming elastomer material on the transmission spectrum of tilted fiber Bragg gratings is presented. Lateral pressure on the elastomer increases its contact angle around the circumference of the fiber and strongly perturbs the optical transmission of the grating. Using an elastomer with a Young's modulus of 20 MPa, a Poisson ratio of 0.48, and a refractive index of 1.42, the sensor reacts monotonically to pressures from 0 to 50 kPa (and linearly from 0 to 15 kPa), with a standard deviation of 0.25 kPa and maximum error of 0.5 kPa. The data are extracted from the optical transmission spectrum using Fourier analysis and we show that this technique makes the response of the sensor independent of temperature, with a maximum error of 2% between 25°C and 75°C. Finally, other pressure ranges can be reached by using conforming materials with different modulii or applying the pressure at different orientations. PMID:21151236

Shao, Li-Yang; Jiang, Qi; Albert, Jacques

2010-12-10

7

Fiber optic pressure sensing with conforming elastomers.  

UK PubMed Central (United Kingdom)

A novel pressure sensing scheme based on the effect of a conforming elastomer material on the transmission spectrum of tilted fiber Bragg gratings is presented. Lateral pressure on the elastomer increases its contact angle around the circumference of the fiber and strongly perturbs the optical transmission of the grating. Using an elastomer with a Young's modulus of 20 MPa, a Poisson ratio of 0.48, and a refractive index of 1.42, the sensor reacts monotonically to pressures from 0 to 50 kPa (and linearly from 0 to 15 kPa), with a standard deviation of 0.25 kPa and maximum error of 0.5 kPa. The data are extracted from the optical transmission spectrum using Fourier analysis and we show that this technique makes the response of the sensor independent of temperature, with a maximum error of 2% between 25°C and 75°C. Finally, other pressure ranges can be reached by using conforming materials with different modulii or applying the pressure at different orientations.

Shao LY; Jiang Q; Albert J

2010-12-01

8

Fiber Optic-Based Refractive Index Sensing at INESC Porto  

Science.gov (United States)

A review of refractive index measurement based on different types of optical fiber sensor configurations and techniques is presented. It addresses the main developments in the area, with particular focus on results obtained at INESC Porto, Portugal. The optical fiber sensing structures studied include those based on Bragg and long period gratings, on micro-interferometers, on plasmonic effects in fibers and on multimode interference in a large spectrum of standard and microstructured optical fibers.

Jorge, Pedro A. S.; Silva, Susana O.; Gouveia, Carlos; Tafulo, Paula; Coelho, Luis; Caldas, Paulo; Viegas, Diana; Rego, Gaspar; Baptista, Jose M.; Santos, Jose L.; Frazao, Orlando

2012-01-01

9

Fiber optic sensing boosts pipeline management efficiency  

Energy Technology Data Exchange (ETDEWEB)

Of utmost importance to pipe-line operators is monitoring of pipeline activities in real-time for parameters such as maintaining oil viscosity and preventing possible pipeline leaks or material degradation and thereby circumventing expensive losses. New fiber optic-based distributed temperature sensing (DTS) equipment can monitor thousands of points along an object`s length, surface, or volume simultaneously. This means that far more precise data are presented to the operator, who then can pinpoint an exact location of any change in activity. Extensive trials with DTS equipment were conducted by Gaz de France (GDF), GDF required a reliable, accurate method of finding leaks in natural gas liquids pipelines in time to prevent potential explosions. GDF began its evaluations of DTS equipment at the Monitor gas terminal. All testing was conducted by the Cryogenic Studies department of its Nantes research division which used York Sensors` DTS system. An optical fiber was laid on an LNG pipeline in which gas had been super-cooled to {minus}160 degrees C. ({minus}320 degrees F.) In this test mode, when a leak occurs, the liquid changes to gas, blows out, and thus develops a cold spot on the pipeline. In the Monitor tests, a DTS was set up to warn operators if the temperature dropped below a certain point so that a potential leak could be investigated before it became serious. In other locations, the DTS system was used to provide long term temperature profiles of underground gas storage reservoirs. Data from these profiles were used for assistance in deciding optimum storage conditions.

Orell, P. [York Sensors Ltd., Hamps (United Kingdom)

1995-02-01

10

Advanced fiber optical chemical sensing networks  

International Nuclear Information System (INIS)

[en] Many industrial processes or other phenomena of interest cannot be measured with conventional instruments because they are too hot, too cold, highly radioactive, or otherwise inaccessible to direct observation. Nuclear wastes stored in underground repositories, for example, will require in-situ monitoring. A new technology that uses long-distance fiber optics to transmit laser-excited fluorescence now makes it possible to remotely monitor such phenomena via optical cables at distances up to a kilometer. The basic system consists of a laser light source, a Raman-fluorescence scattering spectrometer, and an optical fiber linked to a measuring device at the other end. Laser-generated light passes through an aperture and is focused on the end of the optical fiber by a geometric beam splitter. The light passes through the fiber, interacts with the sample to be measured, and returns (now incoherent), where it is reflected by a mirror into the computerized spectrometer for analysis

1986-01-01

11

Photoinduced Electron Transfer Based Ion Sensing within an Optical Fiber  

Directory of Open Access Journals (Sweden)

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.

Florian V. Englich; Tze Cheung Foo; Andrew C. Richardson; Heike Ebendorff-Heidepriem; Christopher J. Sumby; Tanya M. Monro

2011-01-01

12

Extrinsic fiber optic displacement sensors and displacement sensing systems  

Energy Technology Data Exchange (ETDEWEB)

An extrinsic Fizeau fiber optic sensor comprises a single-mode fiber, used as an input/output fiber, and a multimode fiber, used purely as a reflector, to form an air gap within a silica tube that acts as a Fizeau cavity. The Fresnel reflection from the glass/air interface at the front of the air gap (reference reflection) and the reflection from the air/glass interface at the far end of the air gap (sensing reflection) interfere in the input/output fiber. The two fibers are allowed to move in the silica tube, and changes in the air gap length cause changes in the phase difference between the reference reflection and the sensing reflection. This phase difference is observed as changes in intensity of the light monitored at the output arm of a fused biconical tapered coupler. The extrinsic Fizeau fiber optic sensor behaves identically whether it is surface mounted or embedded, which is unique to the extrinsic sensor in contrast to intrinsic Fabry-Perot sensors. The sensor may be modified to provide a quadrature phase shift extrinsic Fizeau fiber optic sensor for the detection of both the amplitude and the relative polarity of dynamically varying strain. The quadrature light signals may be generated by either mechanical or optical means. A plurality of the extrinsic sensors may connected in cascade and multiplexed to allow monitoring by a single analyzer.

Murphy, Kent A. (Roanoke, VA); Gunther, Michael F. (Blacksburg, VA); Vengsarkar, Ashish M. (Scotch Plains, NJ); Claus, Richard O. (Christiansburg, VA)

1994-01-01

13

Extrinsic fiber optic displacement sensors and displacement sensing systems  

Energy Technology Data Exchange (ETDEWEB)

An extrinsic Fizeau fiber optic sensor comprises a single-mode fiber, used as an input/output fiber, and a multimode fiber, used purely as a reflector, to form an air gap within a silica tube that acts as a Fizeau cavity. The Fresnel reflection from the glass/air interface at the front of the air gap (reference reflection) and the reflection from the air/glass interface at the far end of the air gap (sensing reflection) interfere in the input/output fiber. The two fibers are allowed to move in the silica tube, and changes in the air gap length cause changes in the phase difference between the reference reflection and the sensing reflection. This phase difference is observed as changes in intensity of the light monitored at the output arm of a fused biconical tapered coupler. The extrinsic Fizeau fiber optic sensor behaves identically whether it is surface mounted or embedded, which is unique to the extrinsic sensor in contrast to intrinsic Fabry-Perot sensors. The sensor may be modified to provide a quadrature phase shift extrinsic Fizeau fiber optic sensor for the detection of both the amplitude and the relative polarity of dynamically varying strain. The quadrature light signals may be generated by either mechanical or optical means. A plurality of the extrinsic sensors may connected in cascade and multiplexed to allow monitoring by a single analyzer. 14 figures.

Murphy, K.A.; Gunther, M.F.; Vengsarkar, A.M.; Claus, R.O.

1994-04-05

14

Distributed fiber optic sensing enhances pipeline safety and security  

Energy Technology Data Exchange (ETDEWEB)

Pipelines are efficient, highly reliable and safe means of transportation. However, despite intensive right of way surveillance by foot, car and out of the air, pipeline leaks and illegal tappings are a reality - sometimes with catastrophic results. These events show a gap in real-time monitoring caused by the highly distributed nature of pipelines. Parts of this gap now can be closed with distributed fiber optic sensing technology. Using various physical effects this technology is apt to detect temperature, strain, vibrations and sound with very good localization over spans up to 50 km with a single sensor cable. Various field tested applications like leakage detection, third party activity monitoring and intrusion detection or ground movement detection as well as integrity monitoring proof that distributed fiber optic sensing can enhance pipeline safety and security. (orig.)

Frings, Jochen; Walk, Tobias [ILF Consulting Engineers, Munich (Germany)

2011-09-15

15

Optical fiber current sensing based on Faraday effect in optical fiber  

Energy Technology Data Exchange (ETDEWEB)

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)

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

16

Long-distance fiber-optic point-sensing systems based on random fiber lasers.  

UK PubMed Central (United Kingdom)

We find that the random fiber laser (RFL) without point-reflectors is a temperature-insensitive distributed lasing system for the first time. Inspired by such thermal stability, we propose the novel concept of utilizing the RFL to achieve long-distance fiber-optic remote sensing, in which the RFL offers high-fidelity and long-distance transmission for the sensing signal. Two 100 km fiber Bragg grating (FBG) point-sensing schemes based on RFLs are experimentally demonstrated using the first-order and the second-order random lasing, respectively, to verify the concept. Each sensing scheme can achieve >20 dB optical signal-to-noise ratio (OSNR) over 100 km distance. It is found that the second-order random lasing scheme has much better OSNR than that of the first-order random lasing scheme due to enhanced lasing efficiency, by incorporating a 1455 nm FBG into the lasing cavity.

Wang ZN; Rao YJ; Wu H; Li PY; Jiang Y; Jia XH; Zhang WL

2012-07-01

17

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

UK PubMed Central (United Kingdom)

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.

Huang J; Hua L; Lan X; Wei T; Xiao H

2013-07-01

18

Fiber optic sensing detects hot spots in methane reformers  

Energy Technology Data Exchange (ETDEWEB)

Sasol Ltd.`s Mossgas plant, in Mossel Bay, South Africa, is using fiber optic sensing technology to detect potentially hazardous hot spots in its secondary methane reformers. The system is part of a distributed temperature system (DTS) that warns operators when hot spots begin forming. Without such warning, the localized high temperatures could lead to vessel damage or even process shutdown. The Mossgas DTS installation was described in an unpublished report by its manufacturer, York Sensors Ltd., Southampton, U.K. This paper summarizes this report.

NONE

1996-02-19

19

Extreme temperature sensing using brillouin scattering in optical fibers  

CERN Multimedia

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...

Fellay, Alexandre

20

Fiber optic device for sensing the presence of a gas  

Energy Technology Data Exchange (ETDEWEB)

A fiber-optic device for sensing the presence of a gas in an environment is provided. The device comprises a light source for directing a light beam to a layer system having a first surface and a second surface opposite the first surface. The first surface is exposable to the light beam and the second surface is exposable to the environment. A first light portion encounters and reflects from the first surface at an angle of incidence free from optical wave guide resonance phenomenon and the second light portion encounters and reflects from the first surface at an angle of incidence enabling an optical wave guide resonance phenomenon. The layer system is selected to reversibly react with the gas to be detected. The reaction between the gas and the material changes the material's optical properties and the wavelength at which the optical wave guide resonance occurs. Furthermore, a mechanism for measuring the intensity of the reflected first light portion relative to the reflected second light portion is provided with the ratio of the first and second light portions indicating the concentration of the gas presence in the environment.

Benson, David K. (14154 W. First Dr., Golden, CO 80401); Bechinger, Clemens S. (35 S. Holman Way, # 3D, Golden, CO 80401); Tracy, C. Edwin (19012 W. 60th Dr., Golden, CO 80403)

1998-01-01

 
 
 
 
21

Large-area multiplexed sensing using MEMS and fiber optics  

Science.gov (United States)

Micro-electro-mechanical (MEMS) technology offers the ability to implement local and independent sensing and actuation functions through the coordinated response of discrete micro-electro-mechanical 'basis function' elements. The small size of micromechanical components coupled with the ability to reduce costs using volume manufacturing techniques opens up significant potential not only in military applications such as flight and engine monitoring and control, but in autonomous vehicle control, smart munitions, airborne reconnaissance, LADAR, missile guidance, and even in intelligent transportation systems and automotive guidance applications. In this program, Luna Innovations is developing a flexible, programmable interface which can be integrated direction with different types of MEMS sensors, and then used to multiplex many sensors ona single optical fiber to provide a unique combination of functions that will allow larger quantities of sensory input with better resolution than ever before possible.

Miller, Michael B.; Clark, Richard L.; Bell, Clifton R.; Russler, Patrick M.

2000-06-01

22

Perfluorinated Plastic Optical Fiber Tapers for Evanescent Wave Sensing  

Directory of Open Access Journals (Sweden)

Full Text Available In this work we describe the fabrication and the characterization of perfluorinated plastic-cladded optical fiber tapers. The heat-and-pull procedure has been used to fabricate symmetric tapers. Devices with different taper ratio have been produced and the repeatability of the process has been verified. The very low refractive indexes of the core-cladding perfluorinated polymers (n = 1.35–1.34) permit a strong enhancement of the evanescent wave power fraction in aqueous environments (n = 1.33), making them very attractive for evanescent wave sensing. The tapers have been characterized carrying out evanescent field absorbance measurements with different concentrations of methylene blue in water and fluorescence collection measurements in an aqueous solution containing Cy5 dye. A good sensitivity, tightly related to the low refractive index of the core-cladding materials and the geometrical profile, has been shown.

Roberto Gravina; Genni Testa; Romeo Bernini

2009-01-01

23

Distributed fiber-optic temperature sensing for hydrologic systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Instruments for distributed fiber-optic measurement of temperature are now available with temperature resolution of 0.01°C and spatial resolution of 1 m with temporal resolution of fractions of a minute along standard fiber-optic cables used for communication with lengths of up to 30,000 m. We discu...

Selker, John S.; Thévenaz, Luc; Huwald, Hendrik; Mallet, Alfred; Luxemburg, Wim; van de Giesen, Nick; Stejskal, Martin

24

Distributed fiber optical sensing of oxygen with optical time domain reflectometry.  

Science.gov (United States)

In many biological and environmental applications spatially resolved sensing of molecular oxygen is desirable. A powerful tool for distributed measurements is optical time domain reflectometry (OTDR) which is often used in the field of telecommunications. We combine this technique with a novel optical oxygen sensor dye, triangular-[4] phenylene (TP), immobilized in a polymer matrix. The TP luminescence decay time is 86 ns. The short decay time of the sensor dye is suitable to achieve a spatial resolution of some meters. In this paper we present the development and characterization of a reflectometer in the UV range of the electromagnetic spectrum as well as optical oxygen sensing with different fiber arrangements. PMID:23727953

Eich, Susanne; Schmälzlin, Elmar; Löhmannsröben, Hans-Gerd

2013-05-31

25

Novel optical fibers for Brillouin-based distributed sensing  

Science.gov (United States)

Optical fiber sensors utilizing Brillouin scattering rely on the principle that the Brillouin frequency shift is a function of the local temperature or strain. Conventional optical fibers, such as standard telecommunications single-mode fibers, have been successfully used in these applications, and most typically in the time domain, such as with BOTDR. Such conventional fibers however are susceptible simultaneously to both temperature and strain, requiring either at least two fibers or specialized cabling to distinguish the effects of a local stress from those of a local change in temperature. Recently, methods utilizing fibers possessing at least two Brillouin frequency shifts, each with different temperature or strain coefficients have been proposed. However, realizing such fibers is challenging, requiring fibers with regions of very different compositions, all of which must have substantial overlap with the optical field, posing significant manufacturing challenges. We present several new specialty optical fibers based on novel and unconventional fabrication techniques with significant potential for use in distributed fiber sensor systems. First, we describe a class of fibers fabricated from materials whose Brillouin frequency shifts are immune to either temperature or strain, with a demonstration of the former using fiber derived from sapphire crystal, and modeling and measurements predicting the latter. The `Brillouin-athermal' fiber enables the measurement of a local strain, independent of the local temperature. Second, we describe and demonstrate a novel group of longitudinally graded (chirped) fibers enabling easily-implemented frequency-domain systems; affording the potential to simplify and reduce the cost of Brillouin-based distributed sensors.

Dragic, Peter D.; Ballato, John; Morris, Stephanie; Evert, Alex; Rice, Robert R.; Hawkins, Thomas

2013-05-01

26

Antiresonant guiding microstructured optical fibers for sensing applications  

Science.gov (United States)

A novel refractometric sensor utilizing unique spectral properties of antiresonant-guiding microstructured optical fibers is proposed. The sensor operation is based on the wavelength shift of the transmission spectrum in response to the refractive index change of a sample loaded in the air-holes of the microstructured optical fiber. Refractive index changes on the order of 0.1% can be detected using less than a nanoliter of a sample.

Litchinitser, N. M.; Poliakov, E.

2005-07-01

27

Probing the ultimate limit of fiber-optic strain sensing.  

UK PubMed Central (United Kingdom)

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 10(-9) and 10(-6)? hertz (Hz)(-1/2) (where ? is the fractional length change). We report on strain measurements at the 10(-13)?-Hz(-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.

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

2010-11-01

28

Measuring artificial recharge with fiber optic distributed temperature sensing.  

UK PubMed Central (United Kingdom)

Heat was used as a tracer to measure infiltration rates from a recharge basin. The propagation of diurnal oscillation of surface water temperature into the basin bed was monitored along a transect using Fiber Optic Distributed Temperature Sensing (FODTS). The propagation rate was related to downward specific discharge using standard theory of heat advection and dispersion in saturated porous media. An estimate of the temporal variation of heat propagation was achieved using a wavelet transform to find the phase lag between the surface temperature diurnal oscillation and the correlated oscillation at 0.33 and 0.98 m below the bed surface. The wavelet results compared well to a constant velocity model of thermal advection and dispersion during periods of relatively constant discharge rates. The apparent dispersion of heat was found to be due primarily to hydrodynamic mechanisms rather than thermal diffusion. Specific discharge estimates using the FODTS technique also compared well to water balance estimates over a four month period, although there were occasional deviations that have yet to be adequately explained. The FODTS technique is superior to water balance in that it produces estimates of infiltration rate every meter along the cable transect, every half hour. These high resolution measurements highlighted areas of low infiltration and demonstrated the degradation of basin efficiency due to source waters of high suspended solids. FODTS monitoring promises to be a useful tool for diagnosing basin performance in an era of increasing groundwater demand.

Becker MW; Bauer B; Hutchinson A

2013-09-01

29

Research On Fiber Optic Sensing Systems And Their Application As Final Repository Monitoring Tools  

Energy Technology Data Exchange (ETDEWEB)

For several years, fiber-optic sensing devices had been used for straightforward on/off monitoring functions such as presence and position detection. Recently, they gained interest as they offer a novel, exciting technology for a multitude of sensing applications. In the deep geological environment most physical properties, and thus most parameters important to safety, can be measured with fiber-optic technology. Typical examples are displacements, strains, radiation dose and dose rate, presence of some gases, temperature, pressure, etc. Their robustness, immunity to electromagnetic interference, as well as their large bandwidths and data rates ensure high reliability and superior performance. Moreover, the networking capabilities of meanwhile available fiber-optic sensors allow for efficient management of large sensor systems. Distributed sensing with multiple sensing locations on a single fiber reduces significantly the number of cables and connecting points. Reliable, cost effective, and maintenance-free solutions can thus be implemented.

Jobmann, M.; Biurrun, E.

2003-02-24

30

Surface plasmon sensing of gas phase contaminants using optical fiber.  

Energy Technology Data Exchange (ETDEWEB)

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 H{sub 2}, H{sub 2}S, 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 H{sub 2} using this technique and <280 {micro}Torr partial pressures of H{sub 2}S. In addition, a multiple sensor fiber has been demonstrated that allows a single fiber to measure H{sub 2}, H{sub 2}S, and H{sub 2}O without changing the fiber or the analytical system.

Thornberg, Steven Michael; White, Michael I.; Rumpf, Arthur Norman; Pfeifer, Kent Bryant

2009-10-01

31

Perfluorinated Plastic Optical Fiber Tapers for Evanescent Wave Sensing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this work we describe the fabrication and the characterization of perfluorinated plastic-cladded optical fiber tapers. The heat-and-pull procedure has been used to fabricate symmetric tapers. Devices with different taper ratio have been produced and the repeatability of the process has been verif...

Roberto Gravina; Genni Testa; Romeo Bernini

32

Distributed Fiber Optical Sensing of Oxygen with Optical Time Domain Reflectometry  

Directory of Open Access Journals (Sweden)

Full Text Available In many biological and environmental applications spatially resolved sensing of molecular oxygen is desirable. A powerful tool for distributed measurements is optical time domain reflectometry (OTDR) which is often used in the field of telecommunications. We combine this technique with a novel optical oxygen sensor dye, triangular-[4] phenylene (TP), immobilized in a polymer matrix. The TP luminescence decay time is 86 ns. The short decay time of the sensor dye is suitable to achieve a spatial resolution of some meters. In this paper we present the development and characterization of a reflectometer in the UV range of the electromagnetic spectrum as well as optical oxygen sensing with different fiber arrangements.

Susanne Eich; Elmar Schmälzlin; Hans-Gerd Löhmannsröben

2013-01-01

33

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

Science.gov (United States)

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

Kurosawa, Kiyoshi

2013-10-01

34

Polymer optical fiber large strain sensing technology based on bending loss  

Science.gov (United States)

Based on the bending loss theory of polymer optical fiber, mathematical model of polymer optical fiber large strain sensing is established. Three different polymer optical fiber large strain sensitive structures are designed. And a corresponding intensity modulated polymer optical fiber large strain sensing system is established. The different aspects of properties of three designed sensitive structures are researched and compared by the means of ANSYS software simulation and experimental system. Experimental results show that the designed sensor of b-type structure is a large strain sensor, which has good performance. The b-type sensor's strain measurement range has up to 20%, moreover, its non-linear error is approximate 1.4%, and the system has advantages of high sensitivity.

You, Qian; Huang, Yin-Guo; Lin, Yu-Chi

2011-11-01

35

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 locali...

Yongbin Lin; Yang Zou; Yuanyao Mo; Junpeng Guo; Robert G. Lindquist

36

Characterization of flexible copolymer optical fibers for force sensing applications.  

Science.gov (United States)

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. PMID:24021967

Krehel, Marek; Rossi, René M; Bona, Gian-Luca; Scherer, Lukas J

2013-09-09

37

Characterization of flexible copolymer optical fibers for force sensing applications.  

UK PubMed Central (United Kingdom)

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.

Krehel M; Rossi RM; Bona GL; Scherer LJ

2013-01-01

38

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1996-03-01

39

High-resolution absolute frequency referenced fiber optic sensor for quasi-static strain sensing.  

Science.gov (United States)

We present a quasi-static fiber optic strain sensing system capable of resolving signals below nanostrain from 20 mHz. A telecom-grade distributed feedback CW diode laser is locked to a fiber Fabry-Perot sensor, transferring the detected signals onto the laser. An H(13)C(14)N absorption line is then used as a frequency reference to extract accurate low-frequency strain signals from the locked system. PMID:20648185

Lam, Timothy T-Y; Chow, Jong H; Shaddock, Daniel A; Littler, Ian C M; Gagliardi, Gianluca; Gray, Malcolm B; McClelland, David E

2010-07-20

40

High-resolution absolute frequency referenced fiber optic sensor for quasi-static strain sensing  

International Nuclear Information System (INIS)

[en] We present a quasi-static fiber optic strain sensing system capable of resolving signals below nanostrain from 20 mHz. A telecom-grade distributed feedback CW diode laser is locked to a fiber Fabry-Perot sensor, transferring the detected signals onto the laser. An H13C14N absorption line is then used as a frequency reference to extract accurate low-frequency strain signals from the locked system.

2010-07-20

 
 
 
 
41

High-resolution absolute frequency referenced fiber optic sensor for quasi-static strain sensing  

Energy Technology Data Exchange (ETDEWEB)

We present a quasi-static fiber optic strain sensing system capable of resolving signals below nanostrain from 20 mHz. A telecom-grade distributed feedback CW diode laser is locked to a fiber Fabry-Perot sensor, transferring the detected signals onto the laser. An H{sup 13}C{sup 14}N absorption line is then used as a frequency reference to extract accurate low-frequency strain signals from the locked system.

Lam, Timothy T.-Y.; Chow, Jong H.; Shaddock, Daniel A.; Littler, Ian C. M.; Gagliardi, Gianluca; Gray, Malcolm B.; McClelland, David E.

2010-07-20

42

Calibrating Single-Ended Fiber-Optic Raman Spectra Distributed Temperature Sensing Data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hydrologic research is a very demanding application of fiber-optic distributed temperature sensing (DTS) in terms of precision, accuracy and calibration. The physics behind the most frequently used DTS instruments are considered as they apply to four calibration methods for single-ended DTS installa...

Hausner, Mark B.; Suárez, Francisco; Glander, Kenneth E.; van de Giesen, Nick; Selker, John S.; Tyler, Scott W.

43

Double-ended calibration of fiber-optic Raman spectra distributed temperature sensing data:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Van de Giesen, N.C.; Steele-Dunn, S.C.; Jansen, J.; Hoes, O.A.C.; Hausner, M.B.; Tyler, S.; Selker, J.

44

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 typi...

Nick van de Giesen; Susan C. Steele-Dunne; Jop Jansen; Olivier Hoes; Mark B. Hausner; Scott Tyler; John Selker

45

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

van de Giesen, Nick; Steele-Dunne, Susan C.; Jansen, Jop; Hoes, Olivier; Hausner, Mark B.; Tyler, Scott; Selker, John

46

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 us...

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

47

A Multi-D-Shaped Optical Fiber for Refractive Index Sensing  

Directory of Open Access Journals (Sweden)

Full Text Available A novel class of multi-D-shaped optical fiber suited for refractive index measurements is presented. The multi-D-shaped optical fiber was constructed by forming several D-sections in a multimode optical fiber at localized regions with femtosecond laser pulses. The total number of D-shaped zones fabricated could range from three to seven. Each D-shaped zone covered a sensor volume of 100 ?m depth, 250 ?m width, and 1 mm length. The mean roughness of the core surface obtained by the AFM images was 231.7 nm, which is relatively smooth. Results of the tensile test indicated that the fibers have sufficient mechanical strength to resist damage from further processing. The multi-D-shaped optical fiber as a high sensitive refractive-index sensor to detect changes in the surrounding refractive index was studied. The results for different concentrations of sucrose solution show that a resolution of 1.27 × 10?3–3.13 × 10?4 RIU is achieved for refractive indices in the range of 1.333 to 1.403, suggesting that the multi-D-shaped fibers are attractive for chemical, biological, and biochemical sensing with aqueous solutions.

Chien-Hsing Chen; Tzu-Chein Tsao; Jaw-Luen Tang; Wei-Te Wu

2010-01-01

48

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

Science.gov (United States)

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.

Duckworth, Gregory L.; Ku, Emery M.

2013-06-01

49

Comprehensive long distance and real-time pipeline monitoring system based on fiber optic sensing  

Energy Technology Data Exchange (ETDEWEB)

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)

Nikles, Marc; Ravet, Fabien; Briffod, Fabien [Omnisens S.A., Morges (Switzerland)

2009-07-01

50

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 detect a quantity; thus, FLRD is referred to as a time-domain sensing technique. FLRD sensors have near real-time response, multi-pass enhanced high-sensitivity, and relatively low cost (i.e., without using an optical spectral analyzer). During the last eight years since the introduction of the original form of fiber ringdown spectroscopy, there has been increasing interest in the FLRD technique in fiber optic sensor developments, and new application potential is being explored. This paper first discusses the challenging issues in development of multi-function, fiber optic sensors or sensor networks using current fiber optic sensor sensing schemes, and then gives a review on current fiber optic sensor development using FLRD technique. Finally, design perspectives on new generation, multi-function, fiber optic sensor platforms using FLRD technique are particularly presented.

Chuji Wang

2009-01-01

51

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 cel...

Chuji Wang

52

Distributed fiber-optic temperature sensing: recent improvements and Nagra's applications in the Mont Terri URL  

International Nuclear Information System (INIS)

Document available in extended abstract form only. Full text of publication follows: The application of fiber-optic sensors in large experiments in underground rock laboratories (URL) and for monitoring of pilot repositories offers several advantages in contrast to conventional sensors. By means of optical fibers distributed temperature and deformation measurements can be performed without electric or mechanical components at the measurement location reducing the risk of corrosion and sensor failure. As fiber-optic strain sensors are to some extend still in a prototype stage, we focus here on Raman spectra distributed fiber-optic temperature sensing (DTS). In DTS a fiber-optic cable, which is the temperature sensor, is connected to a light reading unit that sends laser-pulses into the fiber. The backscattered light is detected with high temporal resolution. From the two-way-light-travel-time the location of backscattering is determined. For the temperature information the amplitude ratio of the Stokes and anti-Stokes signals is analyzed. The Stokes and anti- Stokes signals are the result of the Raman effect. The ratio of these signals provides a quantity that depends only on the temperature of the fiber at the location of backscatter. With commercial DTS setups it is possible to measure the temperature distribution along several kilometer long cables with a temperature resolution of 0.01 C and a spatial resolution of 1 m. Recent developments in DTS focus on better temperature precision and resolution. This advancement can be achieved by experiment-specific calibration techniques and sensor-layout as well as improved instruments. To realize high spatial resolution (cm range) wrapped fiber-optic cables can be applied. Another promising approach to monitor moisture along a fiber-optic cable installed in unconsolidated material are heatable cables. We will present a selection of the most recent advancements which may improve temperature monitoring in natural and engineered clay-barriers using DTS. In addition, first results and experiences of Nagra's DTS applications in the Mont Terri URL will be presented. Fiber-optic sensors were installed within the Full-Scale Emplacement (FE) Experiment. The FE-experiment is a full-scale heater test also simulating the construction, emplacement and backfilling of a repository tunnel according to the Swiss concept for high level waste. The THM evolution in the host rock (near- and far-field), tunnel lining and the engineered barrier system will be monitored by several hundred conventional sensors. In addition to thermo-resistive conventional temperature sensors fiber-optic cables amend the temperature monitoring. In the host rock 45 m long inclinometer casings are equipped with fiber-optic cables to observe the longitudinal temperature evolution above the tunnel. The temperature distribution at the interface engineered barrier - tunnel lining is planned to be monitored by fiber-optic cables covering the surface of the tunnel lining. The fiber-optics in combination with the conventional temperature sensors will result in detailed insights into non-uniformity of heat transport within the engineered barrier and the host rock caused by spatial and temporal variability of thermal conductivity and therewith saturation and porosity. (authors)

2012-01-01

53

Nanoliter-scale, regenerable ion sensor: sensing with surface functionalized microstructured optical fiber  

Science.gov (United States)

The first nanoliter-scale regenerable ion sensor based on microstructured optical fiber (MOF) is reported. The air holes of the MOF are functionalized with a monoazacrown bearing spiropyran to give a switchable sensor that detects lithium ions down to 100 nM in nanoliter-scale volumes. Ion binding is turned on and off on upon irradiation with light, with the sensor being unaffected by multiple rounds of photoswitching. Unbound ions are flushed from the fiber in the `off' state to allow the sensor to be reused. The integration of an ionophore into the sensor paves the way for the development of highly specific light-based sensing platforms that are readily adaptable to sense a particular ion simply by altering the ionophore design.

Heng, Sabrina; Nguyen, Mai-Chi; Kostecki, Roman; Monro, Tanya M.; Abell, Andrew D.

2013-05-01

54

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

Directory of Open Access Journals (Sweden)

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.

Yongbin Lin; Yang Zou; Yuanyao Mo; Junpeng Guo; Robert G. Lindquist

2010-01-01

55

Double-ended calibration of fiber-optic Raman spectra distributed temperature sensing data.  

UK PubMed Central (United Kingdom)

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.

van de Giesen N; Steele-Dunne SC; Jansen J; Hoes O; Hausner MB; Tyler S; Selker J

2012-01-01

56

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

Directory of Open Access Journals (Sweden)

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.

Nick van de Giesen; Susan C. Steele-Dunne; Jop Jansen; Olivier Hoes; Mark B. Hausner; Scott Tyler; John Selker

2012-01-01

57

Characterizing groundwater flow and heat transport in fractured rock using fiber-optic distributed temperature sensing  

Science.gov (United States)

We show how fully distributed space-time measurements with Fiber-Optic Distributed Temperature Sensing (FO-DTS) can be used to investigate groundwater flow and heat transport in fractured media. Heat injection experiments are combined with temperature measurements along fiber-optic cables installed in boreholes. Thermal dilution tests are shown to enable detection of cross-flowing fractures and quantification of the cross flow rate. A cross borehole thermal tracer test is then analyzed to identify fracture zones that are in hydraulic connection between boreholes and to estimate spatially distributed temperature breakthrough in each fracture zone. This provides a significant improvement compared to classical tracer tests, for which concentration data are usually integrated over the whole abstraction borehole. However, despite providing some complementary results, we find that the main contributive fracture for heat transport is different to that for a solute tracer.

Read, T.; Bour, O.; Bense, V.; Le Borgne, T.; Goderniaux, P.; Klepikova, M. V.; Hochreutener, R.; Lavenant, N.; Boschero, V.

2013-05-01

58

FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS  

Energy Technology Data Exchange (ETDEWEB)

A reflection mode fiber optic oxygen sensor is being developed that can operate at high temperatures for power plant applications. The sensor is based on the {sup 3}O{sub 2} quenching of the red emission from hexanuclear molybdenum chloride clusters. Two critical materials issues are the cluster's ability to withstand high temperatures when immobilized in a porous the sol-gel support, and whether after heating to high temperatures, the sol-gel matrix maintains a high and constant permeability to oxygen to support rapid quenching of luminescence. We used a composite materials approach to prepare stable sensing layers on optical fibers. We dispersed 60 w/w% of a pre-cured sol-gel composite containing the potassium salt of molybdenum clusters (K{sub 2}Mo{sub 6}Cl{sub 14}) into a sol-gel binder solution, and established the conditions necessary for deposition of sol-gel films on optical fibers and planar substrates. The fiber sensor has an output signal of 5 nW when pumped with an inexpensive commercial 365 nm ultraviolet light emitting diode (LED). Quenching of the sensor signal by oxygen was observed up to a gas temperature of 175 C with no degradation of the oxygen permeability of the composite after high temperature cycling. On planar substrates the cluster containing composite responds within <1 second to a gas exchange from nitrogen to oxygen, indicating the feasibility of real-time oxygen detection.

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

2005-07-01

59

An implantable neural sensing microsystem with fiber-optic data transmission and power delivery.  

UK PubMed Central (United Kingdom)

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.

Park S; Borton DA; Kang M; Nurmikko AV; Song YK

2013-01-01

60

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  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2007-07-03

 
 
 
 
61

Design and Fabrication of Fiber-Optic Nanoprobes for Optical Sensing  

Directory of Open Access Journals (Sweden)

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.

Zhang Yan; Dhawan Anuj; Vo-Dinh Tuan

2011-01-01

62

Fiber optic vibration sensor  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-01-01

63

Fiber Optics  

Science.gov (United States)

SFGate: SBC and Microsofthttp://sfgate.com/cgi-bin/article.cgi?file=/c/a/2004/06/23/MNGVR7AI711.DTLSBC Communications Inc.http://www.sbc.com/gen/press-room?pid=5838How Stuff Works: How Fiber Optics Workhttp://electronics.howstuffworks.com/fiber-optic.htmFiber Optic Reference Guide: A Brief Historyhttp://www.fiber-optics.info/fiber-history.htmPC World: Has Your Broadband Had Its Fiber?http://www.pcworld.com/news/article/0,aid,117684,00.aspTelephony Onlinehttp://telephonyonline.com/ar/telecom_breaking_meg_barrier/index.htmThis article from SFGate reports on the recent negotiations between SBC and Microsoft (1) and the implications of the new technology for Internet and television access. This website from SBC (2) provides video footage and background information on their initiative called Project Lightspeed. This initiative is based largely on fiber technology, which is described further on this website from How Stuff Works (3). This website (4) provides a brief history of fiber optics technology along with links to sections on the applications of fiber optics and more basics on transmission. This article from PC World (5) discusses how fiber optics became a viable option. This article from Telephony Online 6)reviews some of the challenges that remain.

64

Preparation and properties of new complex sensing film for fiber optic glucose sensor  

Science.gov (United States)

In this paper, a new complex sensing film containing both optical indicator and enzyme was prepared and its sensing properties were studied, using cellulose acetate (CA) as the carrier and tris (2,2'-blpyridyl) dichloro-ruthenium (II) hexahydrate (Ru(bpy)3Cl2) as the indicator. The cross-linking method was used to immobilize glucose oxidase (GOD). The immobilization conditions were optimized: the concentration of sodium periodate as 0.2 M and the reaction time as 30 min, those for ethanediamine as 0.03 M and 2.5 hours, those for GA as 1.5% (v/v) and 2 hours, those for GOD as 35 mg/ml and 21h. The optimal temperature and pH value for the catalytic properties of the sensing film are 38 °C and 7.0, respectively. A fiber optic glucose sensor with this complex sensing film has been studied. The results show that its detecting range is 100-600 mg/dl and its response time is less than 20 seconds.

Huang, Jun; Wang, Chao; Yuan, Yinquan; Wang, Hai; Ding, Liyun; Fan, Dian

2010-04-01

65

Optical Fiber Networks for Remote Fiber Optic Sensors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Montserrat Fernandez-Vallejo; Manuel Lopez-Amo

66

Fiber optic detector  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1990-12-31

67

Integrated analysis combining microseismic mapping and fiber-optic distributed temperature sensing (DTS)  

Energy Technology Data Exchange (ETDEWEB)

Microseismic mapping has been used for decades to better understand the propagation of fracture networks created during hydraulic fracturing treatments. The ability to accurately evaluate the geometry of a hydraulic fracture treatment and the points of fracture initiation at the near-wellbore provides valuable information. However, accurate production data must be available for each individual stage. Fiber-optic-based distributed temperature sensing (DTS) is a newer technology that provides almost immediate updates of the near-wellbore temperature distribution in one-meter intervals. The benefits of running microseismic mapping and fiber-optic DTS projects as individual diagnostic tools were discussed. The paper showed that the benefits gained from running these tools simultaneously outweighs the benefits of each diagnostic tool on its own. The combination of microseismic information, accurate near-wellbore fluid-travel information from DTS, and accurate production results provides a much better understanding of completion effectiveness by quantifying production rates from each perforation interval, crossflow rate while shut-in, and fluid types recovered from each perforation interval. This paper focused on 3 aspects of combining microseismic mapping with DTS, notably the real-time aspect; the use of both tools to perform more accurate post-fracture analysis; and combining these diagnostic tools with production analysis acquired to temperature data analysis. 9 refs., 12 figs.

Holley, E.H.; Zimmer, U.; Mayerhofer, M.J.; Samson, E. [Pinnacle Technologies, Calgary, AB (Canada)

2010-07-01

68

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

Directory of Open Access Journals (Sweden)

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.

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

2011-01-01

69

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

Directory of Open Access Journals (Sweden)

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.

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

2010-01-01

70

Assessment of detection limits of fiber-optic distributed temperature sensing for detection of illicit connections.  

Science.gov (United States)

Distributed temperature sensing (DTS) with fiber-optic cables is a powerful tool to detect illicit connections in storm sewer systems. High-frequency temperature measurements along the in-sewer cable create a detailed representation of temperature anomalies due to illicit discharges. The detection limits of the monitoring equipment itself are well-known, but there is little information available on detection limits for the discovery of illicit connections, as in mixing of sewers, and attenuation also plays an important role. This paper describes the results of full-scale experiments aiming to quantify the detection limits for illicit connections under various sewer conditions. Based on the results, a new monitoring set-up for (partially) filled sewer conduits has been proposed. PMID:23787308

Nienhuis, Jaap; de Haan, Cornelis; Langeveld, Jeroen; Klootwijk, Martijn; Clemens, François

2013-01-01

71

Assessment of detection limits of fiber-optic distributed temperature sensing for detection of illicit connections.  

UK PubMed Central (United Kingdom)

Distributed temperature sensing (DTS) with fiber-optic cables is a powerful tool to detect illicit connections in storm sewer systems. High-frequency temperature measurements along the in-sewer cable create a detailed representation of temperature anomalies due to illicit discharges. The detection limits of the monitoring equipment itself are well-known, but there is little information available on detection limits for the discovery of illicit connections, as in mixing of sewers, and attenuation also plays an important role. This paper describes the results of full-scale experiments aiming to quantify the detection limits for illicit connections under various sewer conditions. Based on the results, a new monitoring set-up for (partially) filled sewer conduits has been proposed.

Nienhuis J; de Haan C; Langeveld J; Klootwijk M; Clemens F

2013-01-01

72

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2006-09-30

73

Fiber-optic distributed-temperature-sensing technology used for reservoir monitoring in an Indonesia steamflood  

Energy Technology Data Exchange (ETDEWEB)

Case histories of successful applications of fiber-optic Distributed Temperature Sensing (DTS) surveys in steam flood management in a steam flood field in the central Sumatra basin in Indonesia were presented. The field consists of approximately 4,114 producing wells, 1610 steam injectors and 450 temperature observation wells. In addition to determining temperature, DTS profile data can monitor the extent of a steam chest as well as the temperature gradients for over- or under-burden reservoirs, through optic fibres which are composed of concentric layers of materials with a light-carrying core. Back scattered light from the fibre-optic line contains information about the temperature from which it originates. An instrument box pulses the light onto the fibre optics line at certain predetermined time sequences so that the depth at which the information is retrieved can also be determined. The steam flood field used a retrievable fibre rod that was deployed from the surface into pre-installed capillary tubing. The fibre-optic technology with a DTS system and single-ended installation was able to determine real-time temperature profiles in steam flood production wells. Use of the technology contributed to a better understanding of steam break-through zones along the pay-zone interval of production wells. The technology was also able to determine temperature profiles in observation wells and identify steam zone development and unswept zones. Survey results from the study showed identifiable temperature anomalies with very small temperature changes. It was concluded that DTS surveillance data can provide valuable information for identifying steam break-through management on a layer-by-layer basis, as well as eruption mitigation. 3 refs., 10 figs.

Nath, D.K.; Finley, D. [Halliburton Energy Services Inc., Calgary, AB (Canada); Sugianto, R. [PT Caltex Pacific Indonesia (Indonesia)

2005-11-01

74

Optical fiber hydrogen sensor  

Energy Technology Data Exchange (ETDEWEB)

A new type of hydrogen sensor is reported in which an optical fiber is used as the sensing element. The fiber is coated with palladium which expands on exposure to hydrogen. This changes the effective optical path length of the fiber, which is detected by interferometric techniques. Preliminary experiments have demonstrated the effect and suggest a high sensitivity and a wide dynamic range for this kind of sensor. The experimental results are compared to calculated optical path length changes. Application of this kind of sensor to the detection of other chemicals appears feasible.

Butler, M.A.

1984-11-15

75

Distributed Temperature Sensing of the Atmosphere with Fiber Optic Cables of Different Diameters and Albedos  

Science.gov (United States)

Distributed Temperature Sensing (DTS) combines optical time domain reflectrometry and Raman spectrometry to determine temperatures along fiber optic cables. Environmental applications of DTS have taken flight over the past years. The ability to measure temperatures in soils, snow, and water over large distances with high temporal and spatial resolutions and good accuracies has improved insight in many natural processes. Atmospheric measurements have, so far, been hindered by the heating effect of incoming radiation. For this reason, atmospheric sounding with DTS has mainly been limited to night time observations or to the distribution of shading in forested areas. Radiative heating is partially compensated by advection of heat away from the cable. Thermodynamic theory shows that when heated cylinders (cables) are in equilibrium with the advecting wind field, the final temperature scales with the square root of the diameter. By using cables of different diameters, it is, in theory, possible to calculate the actual air temperature by extrapolating the measurements to a diameter of zero. This idea is based on earlier discussions with Dr. Gaylon Campbell. In our experiment, we used cables of different diameters but the noise levels were in general too large, or the diameter differences too small, to obtain very accurate results. We also used cables with different albedos (black and white). Not surprisingly, white cable temperatures were close to air temperature as measured by the adjacent micro-met station. Detailed analysis shows to what extent, and with what accuracy, DTS cables can be used to measure air temperature during the day.

Van De Giesen, N.; Jansen, J.; de Jong, S.; Selker, J. S.

2011-12-01

76

Using ac-field-induced electro-osmosis to accelerate biomolecular binding in fiber-optic sensing chips with microstructures.  

UK PubMed Central (United Kingdom)

This article reports the use of ac-field-induced charges at the corners of microstructures on fiber-optic sensing chips to generate electro-osmotic vortex flows in flow cell channels that can accelerate solute binding on the fiber. The sensing chip made of a cyclic olefin copolymer COC substrate contained a flow cell channel of dimensions 15 mm x 1 mm x 1 mm. A partially unclad optical fiber was placed within the channel. Relief-like strip structures of 25-mum thickness fabricated on the channel bottom were produced with an injection-molding process. The external electric field lines penetrating through the corners of the plastic microstructures induce charges on the corner surfaces to build up electrical double layers. When a high-frequency ac field (approximately 100 kHz) is used to flip the field polarities quickly, neutralization of the induced charge cannot be accomplished. The electrical double layer is therefore sustained. When absorbed charges in the double layer are driven by the external field, electro-osmotic flows are generated. The unclad portion of the fiber was coated with biotin-functionalized gold nanoparticles. The streptavidin solution was filled in the channel from the feeding tube, and the ac field (approximately 50 V/cm) was subsequently turned on for 30 s. The ac-field-induced electro-osmotic flows can accelerate solute transport in the sensing channel to enhance the binding kinetics of streptavidin molecules with biotin probes implanted on the gold nanoparticle surface. As a result, the fiber-optic localized plasmon resonance (FO-LPR) sensing signal becomes steady as soon as the external field is turned off. In contrast, the signal cannot reach steady state until 200-300 s in a typical static sensing cell. A significant reduction in the sensing response time is demonstrated. The binding assay of streptavidin with immobilized biotin on gold nanoparticle-coated sensing fibers was validated using this mixing device. The detection limit for streptavidin of approximately 10(-11) M is close to the reported values obtained using static cells. Similarly, the sensing response time of an orchid Odontoglossum ringspot virus (ORSV) sample was reduced from 1000 to 330 s when an external field was applied to mix the fluid for 60 s, even though the detection limit was maintained.

Chuang Y; Lee CY; Lu SH; Wang SC; Chau LK; Hsieh WH

2010-02-01

77

Analysis of Faraday effect in multimode tellurite glass optical fiber for magneto-optical sensing and monitoring applications.  

Science.gov (United States)

The design and fabrication of a tellurite glass multimode optical fiber for magneto-optical applications are presented and discussed. The analysis of the polarization shows that an optical beam, linearly polarized at the fiber input, changes to elliptically polarized with an ellipticity of 1?4.5 after propagating down the fiber. However, the elliptical distribution remains unchanged with or without an applied magnetic field, demonstrating that no circular dichroism occurs within the fiber. The Verdet constant of the tellurite glass in the fiber is measured to be 28±0.5??rad·(T·m)-1, diverging by less than 3% from the Verdet constant found on the same glass composition in bulk form. These results demonstrate the feasibility to develop reliable tellurite glass fibers by the preform drawing method for magneto-optical applications. PMID:22772128

Shiyu, Yin; Lousteau, Joris; Olivero, Massimo; Merlo, Marco; Boetti, Nadia; Abrate, Silvio; Chen, Qiuling; Chen, Qiuping; Milanese, Daniel

2012-07-01

78

Analysis of Faraday effect in multimode tellurite glass optical fiber for magneto-optical sensing and monitoring applications.  

UK PubMed Central (United Kingdom)

The design and fabrication of a tellurite glass multimode optical fiber for magneto-optical applications are presented and discussed. The analysis of the polarization shows that an optical beam, linearly polarized at the fiber input, changes to elliptically polarized with an ellipticity of 1?4.5 after propagating down the fiber. However, the elliptical distribution remains unchanged with or without an applied magnetic field, demonstrating that no circular dichroism occurs within the fiber. The Verdet constant of the tellurite glass in the fiber is measured to be 28±0.5??rad·(T·m)-1, diverging by less than 3% from the Verdet constant found on the same glass composition in bulk form. These results demonstrate the feasibility to develop reliable tellurite glass fibers by the preform drawing method for magneto-optical applications.

Shiyu Y; Lousteau J; Olivero M; Merlo M; Boetti N; Abrate S; Chen Q; Chen Q; Milanese D

2012-07-01

79

Distributed Temperature Sensing (DTS) using optical fiber probes to constrain heat and fluid transport in the subsurface  

Science.gov (United States)

Conventional methods of capturing densely-spaced in situ subsurface temperature data are limited by the cost, accuracy, and the complexity of employing a network of point measurement devices. Distributed temperature sensing (DTS) using optical fiber is a new technology for providing in situ temperature measurements that are dense in both space and time. We present an application of DTS to record temperature within the hyporheic zone of a gravel bar on the Willamette River, Oregon, USA. Fiber optic probes were constructed by wrapping approximately 100 m of fiber optic cable around 2 m lengths of PVC pipe. The fiber-optic probes were inserted vertically, in wells, into the gravel bar. By integrating the signal every 1.5 m along the length of the fiber optic cable, we were able to sample temperature at 3.5-cm intervals along the length of the pipe and provide continuous time series samples at 5 minute intervals for a total of 7 days. The data will be presented as movies that show propagation of diurnal temperature variations into the subsurface as well as lateral variations in temperature that we tentatively attribute to lateral fluid flow through the gravel bar. The use of DTS probes to measure changes in temperature as a proxy for fluid flow has potential application in a wide variety of fields, including marine geology as well as hydrology.

Squeochs, G.; Lancaster, S. T.; Haggerty, R.; Trehu, A. M.; Selker, J.

2008-05-01

80

Preparation of Tapered Optical Fibers to utilize the Evanescent Field for Sensing Applications  

Directory of Open Access Journals (Sweden)

Full Text Available Optical fibers can be tapered in order to utilize the evanescent field present in the cladding region of the fiber. At the beginning of the taper region most of the power is present in the core. In the down taper region the light in the core region couples to the cladding region where the evanescent field is present. In the up taper region, light in the cladding region again couples back into the core region. Our experiment discusses about the process of tapering and the principle of tapered fiber and their optical spectrum.

Karra. Sony*, Soumya. M

2013-01-01

 
 
 
 
81

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants  

Energy Technology Data Exchange (ETDEWEB)

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. Our approach towards immobilizing the potassium salt of the molybdenum cluster, K{sub 2}Mo{sub 6}Cl{sub 14}, at the far end of an optical fiber is to embed the cluster in a thermally cured sol-gel matrix particle. This particle-in-binder approach affords fibers with greatly improved mechanical properties, as compared to previous approaches. The sensor was characterized in 2-21% gas phase oxygen at 40, 70 and 100 C. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.

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

2006-06-30

82

Thymol blue immobilized on tapered fibers as optical transducer for pH sensing  

Science.gov (United States)

The present work is concerned with the optical characterization of an evanescent wave sensor for pH detection. First, the interaction between the solution containing the acid-base indicator and the fiber core was investigated. Then, the acid-base indicator, thymol blue, was covalently immobilized on the core of a 200/380 micrometers fiber by means of a silylation process of the glass surface. The fiber core surface was modified along a section of 8 mm. A comparison was made using both bare and tapered fibers, with a tapering ratio (fiber diameter/waist diameter) of 2.3. An enhancement in sensitivity of a factor 6 was observed with tapered fibers in the 1/2.5 range, and a sensitivity of 0.05 pH units was attained.

Baldini, Francesco; Ciaccheri, Leonardo; Falai, Alida; Mignani, Anna G.; Rayss, Jan; Sudolski, Grzegorz

1999-02-01

83

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

2008-03-03

84

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.

2004-01-01

85

FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS  

Energy Technology Data Exchange (ETDEWEB)

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. 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.

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

2004-10-01

86

Hierarchically structured nanoporous poly(ionic liquid) membranes: facile preparation and application in fiber-optic pH sensing.  

UK PubMed Central (United Kingdom)

Nanoporous polyelectrolyte membranes with hierarchical and unique pore architectures can be readily made via electrostatic complexation between imidazolium-based poly(ionic liquid)s and poly(acrylic acid) in a variety of morphologies. Coating the membrane onto the surface of an optical fiber resulted in a device with high pH-sensing performance in terms of the response rate and the sensitivity, due to the charge and porous nature of the membrane layer.

Zhao Q; Yin M; Zhang AP; Prescher S; Antonietti M; Yuan J

2013-04-01

87

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

Science.gov (United States)

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

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

2013-08-16

88

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

UK PubMed Central (United Kingdom)

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.

Ohodnicki PR; Buric MP; Brown TD; Matranga C; Wang C; Baltrus J; Andio M

2013-10-01

89

Interferometric Fiber Optic Sensors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Byeong Ha Lee; Young Ho Kim; Kwan Seob Park; Joo Beom Eom; Myoung Jin Kim; Byung Sup Rho; Hae Young Choi

90

Optical Fiber Networks for Remote Fiber Optic Sensors  

Directory of Open Access Journals (Sweden)

Full Text Available 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, pros and cons. Finally, a synopsis of the main factors to take into consideration in the design of a remote sensor system is gathered.

Montserrat Fernandez-Vallejo; Manuel Lopez-Amo

2012-01-01

91

All-optical fiber hydrogen sensor based on annealed Pd-Au sensing nanolayers  

Science.gov (United States)

We report an all-optical fiber hydrogen sensor based on absorption changes of evanescent fields caused by an annealed Pd/Au thin film. The sensor consists of a small piece of standard single-mode fiber (SMF) coated with a Pd/Au thin film sandwiched between two multimode fibers (MMFs). Due to core diameter mismatch the SMF cladding guides light. When the device is exposed to hydrogen the layer refractive index diminishes and causes attenuation changes of the evanescent fields. Adding gold to palladium allows the fabrication of fast, durable, and reliable sensors suitable for the detection of hydrogen concentration below the critical 4%.

Monzón-Hernández, D.; Luna-Moreno, D.; Villatoro, Joel; Badenes, G.

2007-07-01

92

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants  

Energy Technology Data Exchange (ETDEWEB)

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. Previously we described a particle-in-binder approach to immobilizing the potassium salt of a molybdenum cluster, K{sub 2}Mo{sub 6}Cl{sub 14}, at the tips of optical fibers. Compared to previous methods, the particle-in-binder approach affords fibers with greatly improved mechanical properties. We have extensively characterized two fiber sensors at high temperature. We obtain quenching ratios between pure nitrogen and 21% oxygen as high as 3.9 x at 70 C. For the first sensor at 60 C we obtained a {+-} 1% variation in the quenching ratio over 6 cycles of measurement, and monitored the device performance over 23 days. We were able to operate the second sensor continuously for 14 hours at 70 C, and the sensor quenching ratio was stable to 5% over that time period. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.

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

2006-01-01

93

Fluorescence-based aluminum ion sensing using a surface-functionalized microstructured optical fiber.  

UK PubMed Central (United Kingdom)

The first microstructured optical fiber-based sensor platform for aluminum ions using a surface-attached derivative of lumogallion (3), a known fluorescence-based indicator, has been fabricated. These fibers allow for strong evanescent field interactions with the surrounding media because of the small core size while also providing the potential for real-time and distributed measurements. The fluorescence response to aluminum ions was first demonstrated by applying the procedure to glass slides. This was achieved through the covalent attachment of the fluorophore to a polyelectrolyte-coated glass surface and then to the internal holes of a suspended-core microstructured optical fiber to give an effective aluminum sensor. Whereas the sensor platform reported is fabricated for aluminum, the approach is versatile, with applicability to the detection of other ions.

Warren-Smith SC; Heng S; Ebendorff-Heidepriem H; Abell AD; Monro TM

2011-05-01

94

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)

2000-01-01

95

Multichannel optical sensing device  

Energy Technology Data Exchange (ETDEWEB)

A multichannel optical sensing device is disclosed, for measuring the outr sky luminance or illuminance or the luminance or illuminance distribution in a room, comprising a plurality of light receptors, an optical shutter matrix including a plurality of liquid crystal optical shutter elements operable by electrical control signals between light transmitting and light stopping conditions, fiber optic elements connected between the receptors and the shutter elements, a microprocessor based programmable control unit for selectively supplying control signals to the optical shutter elements in a programmable sequence, a photodetector including an optical integrating spherical chamber having an input port for receiving the light from the shutter matrix and at least one detector element in the spherical chamber for producing output signals corresponding to the light, and output units for utilizing the output signals including a storage unit having a control connection to the microprocessor based programmable control unit for storing the output signals under the sequence control of the programmable control unit.

Selkowitz, Stephen E. (Piedmont, CA)

1990-01-01

96

Fiber optic coupled optical sensor  

Energy Technology Data Exchange (ETDEWEB)

A displacement sensor includes a first optical fiber for radiating light to a target, and a second optical fiber for receiving light from the target. The end of the first fiber is adjacent and not axially aligned with the second fiber end. A lens focuses light from the first fiber onto the target and light from the target onto the second fiber.

Fleming, Kevin J. (Albuquerque, NM)

2001-01-01

97

FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS  

Energy Technology Data Exchange (ETDEWEB)

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. Alkali salts of Mo{sub 6}Cl{sub 12} were synthesized and heated to 280 C for one hour in air. Optical measurements of the thermally treated material confirm the potential of the salts as lumophores in high temperature fiber optic sensors. In addition sol-gel films containing Mo{sub 6}Cl{sub 12} were dip coated on quartz substrates and heated at 200 C for one hour. Conditions were developed for successfully immobilizing monomeric complexes that are compatible with sol-gel processing.

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

2004-07-01

98

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)

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.

Shiquan Tao

2006-12-31

99

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants  

Energy Technology Data Exchange (ETDEWEB)

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. Previously we described a particle-in-binder approach to immobilizing the potassium salt of the molybdenum cluster, K{sub 2}Mo{sub 6}Cl{sub 14}, at the tips of optical fibers. Compared to previous methods, the particle-in-binder approach affords fibers with greatly improved mechanical properties. The response of the sensor to oxygen at 40, 70 and 100 C was measured in 2-21% gas phase oxygen. The normalized sensor signal is linear with molar oxygen concentration and fits the theoretical Stern-Volmer relationship. Although the sensitivity decreases with temperature, at 100 C the sensitivity is 160 [O{sub 2}]{sup -1}. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.

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

2006-05-01

100

Fiber Optical Micro-detectors for Oxygen Sensing in Power Plants  

Energy Technology Data Exchange (ETDEWEB)

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. Previously we immobilized the potassium salt of a molybdenum cluster, K{sub 2}M{sub 6}Cl{sub 14}, in a sol-gel matrix and showed that the luminescence is stable after 54 hours at 200 C, but the quenching ratios were low and the films delaminated after thermal cycling due to densification of the matrix. Three new approaches to solve decreased quenching over time and delamination of films off fiber tips were investigated. In the first approach K{sub 2}Mo{sub 6}Cl{sub 14} embedded in cured sol-gel particles were incorporated into a TEOS based sol-gel. These gave enhanced quenching (6x), but delaminated. Our second approach was to use a commercial cyanoacrylate glue to immobilize the particles onto the tip of an optical fiber. This gave better adhesion and good quenching initially, but eventually the glue degraded upon heating. Our third approach was to use a 55% OtMOS/ TEOS sol-gel binder. Films based on this new sol-gel binder show high quenching ({approx}6x) and superior mechanical stability even after thermal cycling. Sensor measurements on an optical fiber containing K{sub 2}Mo{sub 6}Cl{sub 14} embedded in cured sol-gel particles were obtained from 100 to 25 C. The signal intensity in nitrogen was stable at 2.8 {+-} 0.2 nW, and the quenching ratio (ratio of signal in N{sub 2} vs. 21 % O{sub 2}) varied from 4.4 to 6.9X. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.

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

2005-10-01

 
 
 
 
101

Fiber optic monitoring device  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1993-01-01

102

Python fiber optic seal.  

Science.gov (United States)

Sandia National Laboratories has developed a high security fiber optic seal that incorporates tamper resistance features that are not available in commercial fiber optic seals. The Python Seal is a passive fiber optic loop seal designed to give indication...

K. Ystesund J. Bartberger C. Brusseau P. Fleming K. Insch

1993-01-01

103

High-Tg TOPAS microstructured polymer optical fiber for fiber Bragg grating strain sensing at 110 degrees  

DEFF Research Database (Denmark)

We present the fabrication and characterization of fiber Bragg gratings (FBGs) in an endlessly single-mode microstructured polymer optical fiber (mPOF) made of humidity-insensitive high-Tg TOPAS cyclic olefin copolymer. The mPOF is the first made from grade 5013 TOPAS with a glass transition temperature of Tg = 135°C and we experimentally demonstrate high strain operation (2.5%) of the FBG at 98°C and stable operation up to a record high temperature of 110°C. The Bragg wavelengths of the FBGs are around 860 nm, where the propagation loss is 5.1dB/m, close to the fiber loss minimum of 3.67dB/m at 787nm.

Markos, Christos; Stefani, Alessio

2013-01-01

104

FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2005-04-01

105

Fiber optic calorimetry  

Energy Technology Data Exchange (ETDEWEB)

A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processing to allow phase shifts as small as 1 {micro}rad to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 rad of phase shift per mW of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% {sup 240}Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium.

Rudy, C.R.; Bayliss, S.C.; Bracken, D.S. [Los Alamos National Lab., NM (United States); Bush, I.J.; Davis, P.G. [Optiphase, Inc., Van Nuys, CA (United States)

1998-12-31

106

Fiber Optic Calorimetry  

Energy Technology Data Exchange (ETDEWEB)

A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using optical fibers for heat-flow measurements of special nuclear material. This calorimeter uses piezoelectric-generated phase-carrier modulation with subsequent electronic signal processes to allow phase shifts as small as 1 microradian ({micro}rad) to be measured. The sensing element consists of 21-m lengths of single-mode optical fiber wrapped around sample and reference chambers. The sensitivity of the calorimeter was determined to be 74 radians (rad) of phase shift per milliwatt of thermal power. One milliwatt of thermal power is equivalent to 400 mg of plutonium (6% {sup 240}Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium.

Rudy, C.; Bayliss, S.; Bracken, D.; Bush, J.; Davis, P.

1997-12-12

107

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

Directory of Open Access Journals (Sweden)

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.

Bassam Alfeeli; Gary Pickrell; Marc A. Garland; Anbo Wang

2007-01-01

108

Fiber-optic Fourier transform infrared spectroscopy for remote label-free sensing of medical device surface contamination.  

UK PubMed Central (United Kingdom)

As a potential major source of biochemical contamination, medical device surfaces are of critical safety concerns in the clinical practice and public health. The development of innovative sensing methods for accurate and real-time detection of medical device surface contamination is essential to protect patients from high risk infection. In this paper, we demonstrate an alternative fiber-optic Fourier Transform Infrared (FTIR) spectroscopy based sensing approach for remote, non-contact, and label-free detection of biochemical contaminants in the mid-infrared (mid-IR) region. The sensing probe is designed using mid-IR hollow fibers and FTIR measurements are carried out in reflection mode. Bovine Serum Albumin (BSA) and bacterial endotoxin of different concentrations under thoroughly dry condition are used to evaluate the detection sensitivity. The devised system can identify ?0.0025% (?4 × 10(11) molecules) BSA and 0.5% (0.5 EU/ml) endotoxin concentration. The developed sensing approach may be applied to detect various pathogens that pose public health threats.

Hassan M; Tan X; Welle E; Ilev I

2013-05-01

109

Fiber optical distributed temperature and strain sensing system based on Brillouin light scattering  

Science.gov (United States)

In this paper, a two locking lasers BOTDR (Brillouin optical time domain reflectometry) system is demonstrated. Two narrow linewidth DFB lasers are used as the light sources. Their frequencies are locked with a frequency difference of about 11 GHz, which can greatly improve the measurement accuracy and system stability. At a 5-km standard single-mode fiber, distributed temperature measurements can be achieved in lab with a spatial resolution of 10m and a temperature resolution of 2°C.

Li, Yi; Xue, Xianliang; Dong, Xinyong; Zhang, Zaixuan; Jin, Shangzhong

2011-11-01

110

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 laboratory and their capabilities of detecting the respective quantities were demonstrated. Later, all of the sensors were installed in a test grout cube for real-time monitoring. This work presents the results obtained in the laboratory-based experiments as well as the results from the real-time monitoring process in the test cube.

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

2013-01-01

111

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.

2013-01-01

112

Evaluation of temperature distribution sensing method for fast reactor using optical fiber  

International Nuclear Information System (INIS)

Optical fiber sensors (OFSs) have many advantages like flexible configuration, intrinsic immunity for electromagnetic fields, and so on. For these reasons, it is very useful to apply OFSs to fast reactor plants for remote inspection and surveillance. However, under irradiation, because of radiation-induced transmission loss of optical fibers, OFSs have radiation-induced errors. Therefore, to apply OFSs to nuclear facilities, we have to estimate and correct the errors. In this report, Raman Distributed Temperature Sensor (RDTS; one of the OFSs) has been installed at the primary coolant loop of the experimental fast reactor JOYO of JNC (Japan Nuclear Cycle Development Institute). Two correction techniques (correction technique with two thermocouples and correction technique with loop arrangement) for radiation-induced errors have been developed and demonstrated. Because of the radiation-induced loss, measured temperature distributions had radiation-induced errors. However, during the continuous measurements with the total dose of more than 8 x 103[C/kg](3 x 107[R]), the radiation induced errors showed a saturation tendency. In case of the temperature distributions with fluorine doped fiber, with one of the correction techniques, the temperature errors reduced to 1?2degC and the feasibility of the loss correction techniques was demonstrated. For these results, it can be said that RDTS can be applied asperature distribution monitor in harsh radiation environments like fast reactor plants. (author)

1999-01-01

113

FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS  

Energy Technology Data Exchange (ETDEWEB)

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 1 hour at 250 C. Quenching of a factor of 4X between pure nitrogen and 21% oxygen was observed for films cured directly at 200 C. These are promising results for a high temperature fiber optical oxygen sensor based on molybdenum chloride clusters.

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

2005-01-01

114

Fiber optic connector  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1996-01-01

115

Interferometric Fiber Optic Sensors  

Directory of Open Access Journals (Sweden)

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.

Byeong Ha Lee; Young Ho Kim; Kwan Seob Park; Joo Beom Eom; Myoung Jin Kim; Byung Sup Rho; Hae Young Choi

2012-01-01

116

Interferometric fiber optic sensors.  

UK PubMed Central (United Kingdom)

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.

Lee BH; Kim YH; Park KS; Eom JB; Kim MJ; Rho BS; Choi HY

2012-01-01

117

Fiber optic monitoring device  

Energy Technology Data Exchange (ETDEWEB)

This invention is comprised of 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.

Samborsky, J.K.

1992-12-31

118

A Sensing Element Based on a Bent and Elongated Grooved Polymer Optical Fiber  

Directory of Open Access Journals (Sweden)

Full Text Available An experimental and numerical investigation is performed into the power loss induced in grooved polymer optical fibers (POFs) subjected to combined bending and elongation deformations. The power loss is examined as a function of both the groove depth and the bend radius. An elastic-plastic three-dimensional finite element model is constructed to simulate the deformation in the grooved region of the deformed specimens. The results indicate that the power loss increases significantly with an increasing bending displacement or groove depth. Specifically, the power loss increases to as much as 12% given a groove depth of 1.1 mm and a bending displacement of 10 mm. Based on the experimental results, an empirical expression is formulated to relate the power loss with the bending displacement for a given groove depth. It is shown that the difference between the estimated power loss and the actual power loss is less than 2%.

Wei-Hua Lu; Li-Wen Chen; Wen-Fu Xie; Yung-Chuan Chen

2012-01-01

119

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish 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 (more) 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 monitoring. The interrogation technique for low coherence interferometric sensor with signal processing in spectral domain is described. The measurement uncertainties for temperature (more) and relative humidity measurements no worse than 0.01°C and 4%, respectively, have been achieved experimentally.

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

2010-06-01

120

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

Science.gov (United States)

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.

Villalba, Sergi; Casas, Joan R.

2013-08-01

 
 
 
 
121

Fiber optic ring network  

Energy Technology Data Exchange (ETDEWEB)

An optical fiber cable distribution architecture and a ring interface are described. The unique synergism of the ring configuration coupled with a widespread optical fiber cable facility are explored. The ring interface adapts a token passing network of work-stations from coaxial cable to 50 micron core, telecommunications type, fiber optic cable. The optical fiber cable links a series of communications centers to as many as 288 optical fibers. The loop distribution of optical fibers forms the backbone for a 6.7 km ring operating at 6 to 12 Mbps.

Gossage, S.A.

1985-01-01

122

The suitability of Surface Enhanced Raman Spectroscopy (SERS) to fiber optic chemical sensing of aromatic hydrocarbon contamination in groundwater  

Energy Technology Data Exchange (ETDEWEB)

A general need exists for chemical sensors to monitor the presence, evolution and hydrological transport of aromatic hydrocarbon contamination in oceans surface and ground waters. In the most favorable configuration, a chemical sensor should operate in situ and produce quantitative information in real time with a high level of sensitivity. We are investigating the development of a prototype fiber optic chemical sensing probe based on Surface Enhanced Raman Spectroscopy (SERS) on electrodes. The SERS signal is obtained form the Raman scattering of a molecule absorbed onto a roughened metal substrate. The metal substrates that we have investigated with the fiber optic SERS probe (FOSP) are electrodes made of Ag. With this technique, the SERS-related phenomena that are chemically specific, such as the adsorption of organic molecules on metal substrates and the potential dependence of electrosorption, have increased the selectivity. Our results indicate that the FOSP has the capability of providing information about in situ organic contamination that is both sensitive and selective.

Carrabba, M.M.; Edmonds, R.B.; Marren, P.J.; Rauh, R.D.

1988-01-01

123

Fiber optics in adverse environments  

International Nuclear Information System (INIS)

[en] Radiation effects in optical fibers are considered, taking into account recent progress in the investigation of radiation resistant optical fibers, radiation damage in optical fibers, radiation-induced transient absorption in optical fibers, X-ray-induced transient attenuation at low temperatures in polymer clad silica (PCS) fibers, optical fiber composition and radiation hardness, the response of irradiated optical waveguides at low temperatures, and the effect of ionizing radiation on fiber-optic waveguides. Other topics explored are related to environmental effects on components of fiber optic systems, and radiation detection systems using optical fibers. Fiber optic systems in adverse environments are also discussed, giving attention to the survivability of Army fiber optics systems, space application of fiber optics systems, fiber optic wavelength multiplexing for civil aviation applications, a new fiber optic data bus topology, fiber optics for aircraft engine/inlet control, and application of fiber optics in high voltage substations

1982-01-01

124

Rayleigh fiber optics gyroscope  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

125

A Bragg Wavelength-Insensitive Fiber Bragg Grating Ultrasound Sensing System that Uses a Broadband Light and No Optical Filter  

Directory of Open Access Journals (Sweden)

Full Text Available An optical filter is incorporated in a conventional ultrasound detection system that uses a fiber Bragg grating (FBG) and broadband light source, to demodulate the FBG sensor signal. A novel ultrasound sensing system that does not require an optical filter is presented herein. Ultrasound could be detected via the application of signal processing techniques, such as signal averaging and frequency filters, to the photodetector output that corresponds to the intensity of the reflected light from a broadband light-illuminated FBG. Ultrasonic sensitivity was observed to be enhanced when an FBG was installed as a resonant sensor. This FBG ultrasound detection system is small and cheap to fabricate because it does not use a demodulating optical filter. The experimental results demonstrate that this system could be applied to ultrasonic damage inspection and acoustic emission measurements. Furthermore, this system was able to detect ultrasound despite the amount of strain or temperature that was applied to the FBG sensor because the ultrasound detection was not sensitive to the Bragg wavelength of the FBG sensor.

Hiroshi Tsuda

2011-01-01

126

Omnidirectional fiber optic tiltmeter  

Science.gov (United States)

A tiltmeter is provided which is useful in detecting very small movements such as earth tides. The device comprises a single optical fiber, and an associated weight affixed thereto, suspended from a support to form a pendulum. A light source, e.g., a light emitting diode, mounted on the support transmits light through the optical fiber to a group of further optical fibers located adjacent to but spaced from the free end of the single optical fiber so that displacement of the single optical fiber with respect to the group will result in a change in the amount of light received by the individual optical fibers of the group. Photodetectors individually connectd to the fibers produce corresponding electrical outputs which are differentially compared and processed to produce a resultant continuous analog output representative of the amount and direction of displacement of the single optical fiber.

Benjamin, B.C.; Miller, H.M.

1983-06-30

127

Distributed flow sensing using optical hot -wire grid.  

UK PubMed Central (United Kingdom)

An optical hot-wire flow sensing grid is presented using a single piece of self-heated optical fiber to perform distributed flow measurement. The flow-induced temperature loss profiles along the fiber are interrogated by the in-fiber Rayleigh backscattering, and spatially resolved in millimeter resolution using optical frequency domain reflectometry (OFDR). The flow rate, position, and flow direction are retrieved simultaneously. Both electrical and optical on-fiber heating were demonstrated to suit different flow sensing applications.

Chen T; Wang Q; Zhang B; Chen R; Chen KP

2012-04-01

128

Hydrogen Optical Fiber Sensors  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2008-07-28

129

Highly sensitive and simple method for refractive index sensing of liquids in microstructured optical fibers using four-wave mixing  

DEFF Research Database (Denmark)

We present both experimental measurements and simulations for a simple fiber-optical liquid refractive index sensor, made using only commercially available components and without advanced postprocessing of the fiber. Despite the simplicity, we obtain the highest sensitivity experimentally demonstrated to date for aqueous solutions (refractive index around 1.33), which is relevant for extensions to biosensing. The sensor is based on measuring the spectral shift of peaks arising from four-wave mixing (FWM), when filling the holes of a microstructured fiber with different liquid samples and propagating nanosecond pulses through the silica-core of the fiber. To the best of our knowledge, this is also the first experiment where a liquid is filled into the holes of a solid-core microstructured fiber to control the phase-match conditions for FWM. (C) 2011 Optical Society of America

Frosz, Michael Henoch; Stefani, Alessio

2011-01-01

130

Multimaterial photosensitive fiber constructs enable large-area optical sensing and imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The process of optical imaging and the use of a glass lens have been hitherto inseparable since it is the lens that is responsible for mapping incoming rays to form an image. While performing this critical role, the lens, by virtue of its geometry and materials composition, presents constraints on t...

Abouraddy, Ayman F.; Fink, Yoel

131

Fiber optic detector for immuno-testing  

Energy Technology Data Exchange (ETDEWEB)

A portable fiber optic detector that senses the presence of specific target chemicals in air or a gas by exchanging the target chemical for a fluoroescently-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.

Partin, Judy K. (Idaho Falls, ID); Ward, Thomas E. (Idaho Falls, ID); Grey, Alan E. (Idaho Falls, ID)

1992-01-01

132

Fiber Optic Acoustic Sensor.  

Science.gov (United States)

This patent application relates to an optical fiber acoustical sensor for detecting sound waves in a fluid medium. An optical fiber coil through which a light beam is transmitted is placed in a fluid medium. A sound wave propagating through the fluid medi...

J. A. Bucaro E. F. Carome H. D. Dardy

1978-01-01

133

FIBER OPTICAL MICRO-DETECTORS FOR OXYGEN SENSING IN POWER PLANTS  

Energy Technology Data Exchange (ETDEWEB)

In this report, initial results pertaining to the synthesis molybdenum clusters and characterization using absorption, optical microscopy, and x-ray powder diffraction are discussed. The synthesis was performed according to literature [1], but results from x-ray powder diffraction indicate that the synthesis did not give the desired compound. The absorption and optical microscopy indicate that the compound synthesized has properties similar to the desired Mo{sub 6}Cl{sub 12} clusters [2,3], so it is unclear as of yet what happened. The sample cell for performing high temperature spectroscopy on thin films of the molybdenum clusters at elevated temperature in a controlled gas environment was designed and an initial prototype was built.

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

2003-01-01

134

Fiber optic hydrophone  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1994-01-01

135

Fiber Optics Basics  

Science.gov (United States)

This pdf from OP-TEC, the National Center for Optics and Photonics Education, addresses basic concepts underlying the operation of fiber lasers. This free 26 page document supplements the fiber laser material presented in an Elements of Photonics Course by provided a more current and detailed description of how lasers operate. This course covers basic laser operations, basic structure of fiber lasers, pulsing methods, output characteristics of fiber lasers, and advanced structures.

2012-12-04

136

Fiber optic spanner  

Science.gov (United States)

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.

Black, Bryan; Mohanty, Samarendra

2011-10-01

137

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

1998-01-01

138

Fiber Optic Cables  

Science.gov (United States)

This brief interactive activity, by the Electromechanical Digital Library and Wisconsin Technical College System faculty, is an easy-to-use introduction to fiber optic cables and their uses. Students are able to reveal each section at their leisure as they click through the helpful illustrations and animations on fiber optic cable components, LEDâÂÂs, multi-mode and single-mode cables, and cable connectors. Three review questions wrap up the slide show to test knowledge gained. This would be a great resource for teachers to help introduce the topic to students, or for students to have a comprehensive overview of fiber optic cables.

Bartelt, Terry L.

2009-04-28

139

Fiber optic communication links  

Energy Technology Data Exchange (ETDEWEB)

Fiber optics is a new, emerging technology which offers relief from many of the problems which limited past communications links. Its inherent noise immunity and high bandwidth open the door for new designs with greater capabilities. Being a new technology, certain problems can be encountered in specifying and installing a fiber optic link. A general fiber optic system is discussed with emphasis on the advantages and disadvantages. It is not intended to be technical in nature, but a general discussion. Finally, a general purpose prototype Sandia communications link is presented.

Meyer, R. H.

1980-01-01

140

Optical fiber head for providing lateral viewing  

Energy Technology Data Exchange (ETDEWEB)

The head of an optical fiber comprising the sensing probe of an optical heterodyne sensing device includes a planar surface that intersects the perpendicular to axial centerline of the fiber at a polishing angle .theta.. The planar surface is coated with a reflective material so that light traveling axially through the fiber is reflected transverse to the fiber's axial centerline, and is emitted laterally through the side of the fiber. Alternatively, the planar surface can be left uncoated. The polishing angle .theta. must be no greater than 39.degree. or must be at least 51.degree.. The emitted light is reflected from adjacent biological tissue, collected by the head, and then processed to provide real-time images of the tissue. The method for forming the planar surface includes shearing the end of the optical fiber and applying the reflective material before removing the buffer that circumscribes the cladding and the core.

Everett, Matthew J. (Livermore, CA); Colston, Billy W. (Livermore, CA); James, Dale L. (Tracy, CA); Brown, Steve (Livermore, CA); Da Silva, Luiz (Danville, CA)

2002-01-01

 
 
 
 
141

Polymer optical fiber fuse  

CERN Multimedia

Although high-transmission-capacity optical fibers are in demand, the problem of the fiber fuse phenomenon needs to be resolved to prevent the destruction of fibers. As polymer optical fibers become more prevalent, clarifying their fuse properties has become important. Here, we experimentally demonstrate a fuse propagation velocity of 21.9 mm/s, which is 1 to 2 orders of magnitude slower than that in standard silica fibers. The achieved threshold power density and proportionality constant between the propagation velocity and the power density are respectively 1/186 of and 16.8 times the values for silica fibers. An oscillatory continuous curve instead of periodic voids is formed after the passage of the fuse. An easy fuse termination method is presented herein, along with its potential plasma applications.

Mizuno, Yosuke; Tanaka, Hiroki; Nakamura, Kentaro

2013-01-01

142

Optic radiation fiber tractography in glioma patients based on high angular resolution diffusion imaging with compressed sensing compared with diffusion tensor imaging - initial experience.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Up to now, fiber tractography in the clinical routine is mostly based on diffusion tensor imaging (DTI). However, there are known drawbacks in the resolution of crossing or kissing fibers and in the vicinity of a tumor or edema. These restrictions can be overcome by tractography based on High Angular Resolution Diffusion Imaging (HARDI) which in turn requires larger numbers of gradients resulting in longer acquisition times. Using compressed sensing (CS) techniques, HARDI signals can be obtained by using less non-collinear diffusion gradients, thus enabling the use of HARDI-based fiber tractography in the clinical routine. METHODS: Eight patients with gliomas in the temporal lobe, in proximity to the optic radiation (OR), underwent 3T MRI including a diffusion-weighted dataset with 30 gradient directions. Fiber tractography of the OR using a deterministic streamline algorithm based on DTI was compared to tractography based on reconstructed diffusion signals using HARDI+CS. RESULTS: HARDI+CS based tractography displayed the OR more conclusively compared to the DTI-based results in all eight cases. In particular, the potential of HARDI+CS-based tractography was observed for cases of high grade gliomas with significant peritumoral edema, larger tumor size or closer proximity of tumor and reconstructed fiber tract. CONCLUSIONS: Overcoming the problem of long acquisition times, HARDI+CS seems to be a promising basis for fiber tractography of the OR in regions of disturbed diffusion, areas of high interest in glioma surgery.

Kuhnt D; Bauer MH; Sommer J; Merhof D; Nimsky C

2013-01-01

143

Fiber optic hydrogen sensor  

Energy Technology Data Exchange (ETDEWEB)

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.

Buchanan, B.R.; Prather, W.S.

1991-01-01

144

Fiber optic hydrogen sensor  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1992-01-01

145

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

International Nuclear Information System (INIS)

[en] 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

2008-01-01

146

Nonadiabatic tapered optical fiber for biosensor applications  

Science.gov (United States)

A brief review on biconical tapered fiber sensors for biosensing applications is presented. A variety of configurations and formats of this sensor have been devised for label free biosensing based on measuring small refractive index changes. The biconical nonadiabatic tapered optical fiber offers a number of favorable properties for optical sensing, which have been exploited in several biosensing applications, including cell, protein, and DNA sensors. The types of these sensors present a low-cost fiber biosensor featuring a miniature sensing probe, label-free direct detection, and high sensitivity.

Latifi, Hamid; Zibaii, Mohammad I.; Hosseini, Seyed M.; Jorge, Pedro

2012-12-01

147

Optical fibers in medicine III  

Energy Technology Data Exchange (ETDEWEB)

This book presents the proceedings of a conference of the International Society for Optical Engineering. Topics covered include: Development of antibody - based fiber optic sensors and Fiber optic probe for in situ fluorescence measurements.

Katzir, A.

1988-01-01

148

Optical fiber switch  

Energy Technology Data Exchange (ETDEWEB)

Optical fiber switches operated by electrical activation of at least one laser light modulator through which laser light is directed into at least one polarizer are used for the sequential transport of laser light from a single laser into a plurality of optical fibers. In one embodiment of the invention, laser light from a single excitation laser is sequentially transported to a plurality of optical fibers which in turn transport the laser light to separate individual remotely located laser fuel ignitors. The invention can be operated electro-optically with no need for any mechanical or moving parts, or, alternatively, can be operated electro-mechanically. The invention can be used to switch either pulsed or continuous wave laser light.

Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

2002-01-01

149

Lanthanide upconversion within microstructured optical fibers: improved detection limits for sensing and the demonstration of a new tool for nanocrystal characterization.  

UK PubMed Central (United Kingdom)

We investigate a powerful new sensing platform based on the excitation of upconversion luminescence from NaYF(4):Yb/Er nanocrystals loaded in solution within a suspended-core microstructured optical fiber. We demonstrate a substantial improvement in the detection limit that can be achieved in a suspended-core fiber sensor for solution-based measurements using these nanocrystals as an alternative to more traditional fluorophores, with sensing of concentrations as low as 660 fM demonstrated compared with the 10 pM obtained using quantum dots. This nanocrystal loaded suspended core fiber platform also forms the basis for a novel and robust nanoscale spectrometry device capable of capturing power-dependent spectra over a large dynamic range from 10(3) W cm(-2) to 10(6) W cm(-2) using a laser diode. This serves as a useful tool to study the multiple energy levels of rare earth luminescent nano-materials, allowing the two sharp emission bands to be studied in detail over a large dynamic range of excitation powers. Thus, in addition to demonstrating a highly sensitive dip sensor, we have devised a powerful new approach for characterizing upconversion nanoparticles.

Schartner EP; Jin D; Ebendorff-Heidepriem H; Piper JA; Lu Z; Monro TM

2012-12-01

150

Optical-fiber penetration devices  

International Nuclear Information System (INIS)

[en] Optical communications use optical-fiber signal-transmission lines and optical-fiber penetration instead of conventional wire penetration. Optical-fiber penetration devices must be gastight and have low transmission losses, characteristics which must be guaranteed irrespective of ambient conditions. Mitsubishi Electric has developed two methods of optical-fiber penetration, which are introduced in the article: hermetically sealed and organic material sealed. Both provide excellent resistance to environmental factors, including heat, radiation, and seismic distrubance. (author)

1984-01-01

151

Power Loss Characteristics of a Sensing Element Based on a Polymer Optical Fiber under Cyclic Tensile Elongation  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, power losses in polymer optical fiber (POF) subjected to cyclic tensile loadings are studied experimentally. The parameters discussed are the cyclic load level and the number of cycles. The results indicate that the power loss in POF specimens increases with increasing load level or number of cycles. The power loss can reach as high as 18.3% after 100 cyclic loadings. Based on the experimental results, a linear equation is proposed to estimate the relationship between the power loss and the number of cycles. The difference between the estimated results and the experimental results is found to be less than 3%.

Yung-Chuan Chen; Li-Wen Chen; Wei-Hua Lu

2011-01-01

152

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.)

1998-01-01

153

Assessment of fiber optic pressure sensors  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-04-01

154

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

1995-01-01

155

Self focusing optical fiber  

International Nuclear Information System (INIS)

[en] The invention relates to the field of optoelectronics and may be used in the fiber/optic data transmission systems. Summary of the invention consists in that the self focusing optical fiber contains a shell with a core, placed between two control electrodes. With that the shell is made in the form of a plastic tube, and the core - in the form of a colloidal suspention of PbTiO3 and SrTiO3 powders in the polyethilsiloxane oil

2002-03-26

156

Enhanced radiation resistant fiber optics  

Energy Technology Data Exchange (ETDEWEB)

A process for producing an optical fiber having enhanced radiation resitance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation.

Lyons, Peter B. (Los Alamos, NM); Looney, Larry D. (Los Alamos, NM)

1993-01-01

157

Aerogel-clad optical fiber  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1997-01-01

158

Fiber-optic pressure sensor  

Science.gov (United States)

A pressure wave sensor utilizing fiber optic interferometry techniques to determine pressure in a bar. Light from a fiber optic coil around the bar is mixed with light from a reference optical fiber to produce interference fringes as a function of time. These fringes over time are related to the pressure versus time existing in the bar. 2 figs.

Dingus, R.S.

1989-03-10

159

Large core fiber optic cleaver  

Energy Technology Data Exchange (ETDEWEB)

The present invention relates to a device and method for cleaving optical fibers which yields cleaved optical fiber ends possessing high damage threshold surfaces. The device can be used to cleave optical fibers with core diameters greater than 400 {micro}m. 30 figs.

Halpin, J.M.

1996-03-26

160

Fiber Optics: A Research Paper.  

Science.gov (United States)

Some basic aspects concerning fiber optics are examined. Some history leading up to the development of optical fibers which are now used in the transmission of data in many areas of the world is discussed. Basic theory of the operation of fiber optics is ...

M. M. Drone

1987-01-01

 
 
 
 
161

Large core fiber optic cleaver  

Energy Technology Data Exchange (ETDEWEB)

The present invention relates to a device and method for cleaving optical fibers which yields cleaved optical fiber ends possessing high damage threshold surfaces. The device can be used to cleave optical fibers with core diameters greater than 400 .mu.m.

Halpin, John M. (Livermore, CA)

1996-01-01

162

Ultrasensitive fiber enhanced UV resonance Raman sensing of drugs.  

UK PubMed Central (United Kingdom)

Fiber enhanced UV resonance Raman spectroscopy is introduced for chemical selective and ultrasensitive analysis of drugs in aqueous media. The application of hollow-core optical fibers provides a miniaturized sample container for analyte flow and efficient light-guiding, thus leading to strong light-analyte interactions and highly improved analytical sensitivity with the lowest sample demand. The Raman signals of the important antimalaria drugs chloroquine and mefloquine were strongly enhanced utilizing deep UV and electronic resonant excitation augmented by fiber enhancement. An experimental design was developed and realized for reproducible and quantitative Raman fiber sensing, thus the enhanced Raman signals of the pharmaceuticals show excellent linear relationship with sample concentration. A thorough model accounts for the different effects on signal performance in resonance Raman fiber sensing, and conclusions are drawn how to improve fiber enhanced Raman spectroscopy (FERS) for chemical selective analysis with picomolar sensitivity.

Frosch T; Yan D; Popp J

2013-07-01

163

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.

1989-01-01

164

In-fiber integrated chemiluminiscence online optical fiber sensor.  

UK PubMed Central (United Kingdom)

We report an in-fiber integrated chemiluminiscence (CL) sensor based on a kind of hollow optical fiber with a suspended inner core. The path of microfluid is realized by etching microholes for inlets and outlets on the surface of the optical fiber without damaging the inner core and then constructing a melted point beside the microhole of the outlet. When samples are injected into the fiber, the liquids can be fully mixed and form steady microflows. Simultaneously, the photon emitted from the CL reaction is efficiently coupled into the core and can be detected at the end of the optical fiber. In this Letter, the concentration of H2O2 samples is analyzed through the emission intensity of the CL reaction among H2O2, luminol, K3Fe(CN)6, and NaOH in the optical fiber. The linear sensing range of 0.1-4.0 mmol/L of H2O2 concentration is obtained. The emission intensity can be determined within 400 ms at a total flow rate of 150 ?L/min. Significantly, this work presents the information of developing in-fiber integrated online analyzing devices based on optical methods.

Yang X; Yuan T; Yang J; Dong B; Liu Y; Zheng Y; Yuan L

2013-09-01

165

Nonlinear fiber optics  

CERN Multimedia

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

Agrawal, Govind

2012-01-01

166

High temperature fiber optics  

Science.gov (United States)

The ability to grow continuous lengths of sapphire fiber optic filament in a controlled and reproducible manner was demonstrated through growth of consistent lengths exceeding five meters in length. In total, over sixty meters of filament was grown, with over thirty-nine meters delivered to METC. As discussed within this study, a number of variables can affect the optical transmission level of a sapphire filament. Measurement of the effect of these various parameters was accomplished through relative measurements and ranking of experimental sample groups. These qualitative evaluation techniques limited the ability to pinpoint cause/effect relationships, and restricted the ability to optimize the fiber optic filament growth process. To more fully optimize the growth process, the ability to reproducibly analyze numerous samples should be established. Further optimization of the growth process would include studying the effect of raw material and atmosphere on the optical quality of the fiber. The lowest transmission loss measured was 13.67 dB/meter. Evaluation results for the final twenty meters will further define the consistency of the sample preparation and transmission measurement techniques, while also further demonstrating the consistency of the grown sapphire filament.

Fitzgibbon, J. J.; Labelle, H. E.

167

Fiber optic multimode displacement sensor  

Energy Technology Data Exchange (ETDEWEB)

An underwater Optical Motion Sensor (OMS) based on a design first presented by W. B. Spillman, {ital Schlieren} {ital multimode} {ital fiber}-{ital optic} {ital hydrophone}, Applied Physics Letters 37(2), 15 July 1980, p. 145{endash}146 is described. The displacement sensor uses the same acoustooptical intensity modulation mechanism as Spillman, however the sensing mechanism is isolated from the ambient fluid environment by a small cylindrical aluminum enclosure (1{double_prime} OD{times}3/4{double_prime}). The enclosure contains an inertial mass and the fiber collimators. The inertial mass is suspended in the center of the enclosure by three small wires rigidly mounted to the walls. The mass and wires act as a cantilever beam system with a mechanical resonance near 100 Hz. The transduction mechanism consists of two opposed optical gratings aligned and positioned between the fiber collimators. One grating is mounted on the inertial mass while the other is mounted on the lower end cap of the enclosure. Relative motion between the gratings causes a modulation of the light transmitted through the gratings. The modulated beam is focused onto a photodetector and converted to electric current. The frequency response is flat from 200 Hz{endash}9 kHz with a minimum detectable displacement of 0.002 A and the dynamic range is 136 dB. The small size and light weight give the sensor an effective density of 1.08 g/cm{sup 3} making it almost neutrally buoyant in water. This in conjunction with the performance characteristics make this sensor suitable for use in acoustical sensing applications. {copyright} {ital 1996 American Institute of Physics.}

Fisher, K.A.; Jarzynski, J. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States)

1996-04-01

168

Fiber optic geophysical sensors  

Energy Technology Data Exchange (ETDEWEB)

A fiber optic geophysical sensor in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects.

Homuth, Emil F. (Los Alamos, NM)

1991-01-01

169

Fiber Optic Velocity Interferometry  

Energy Technology Data Exchange (ETDEWEB)

This paper explores the use of a new velocity measurement technique that has several advantages over existing techniques. It uses an optical fiber to carry coherent light to and from a moving target. A Fabry-Perot interferometer, formed by a gradient index lens and the moving target, produces fringes with a frequency proportional to the target velocity. This technique can measure velocities up to 10 km/s, is accurate, portable, and completely noninvasive.

Neyer, Barry T.

1988-04-01

170

Design of optical fiber cables  

Energy Technology Data Exchange (ETDEWEB)

The cables that optical fibers are made into are discussed. Due to the fragile nature of optical fibers, the cables must supply protection from damage during manufacture, installation, and service. Common operating temperatures range from -55 to 155/sup 0/C, creating another critical demand on cables. Two specific designs are analyzed. Attention increments and fiber strength are topics of discussion.

Ramsay, M.M.; Russell, J.N.; Titchmarsh, J.G.

1982-01-01

171

Optical fibers for FTTH application  

Science.gov (United States)

In this paper the specifics of FTTH (Fiber To The Home) networks in terms of requirements for optical fibers has been presented. Optical fiber samples used in FTTH applications acquired from the worldwide leading manufacturers were subjected to small diameter mandrel wraps tests. The detailed procedures of performed tests and the measurement results has been presented.

Guzowski, Bartlomiej; Tosik, Grzegorz; Lisik, Zbigniew; Bedyk, Michal; Kubiak, Andrzej

2013-07-01

172

Longitudinally graded optical fibers  

Science.gov (United States)

Described herein, for the first time to the best of our knowledge, are results on optical fibers possessing significant compositional gradations along its length due to longitudinal control of the core glass composition. More specifically, MCVD-derived germanosilicate fibers were fabricated that exhibited a gradient of up to about 0.55 weight % GeO2 per meter. These gradients are about 1900 times greater than previously reported fibers possessing longitudinal changes in composition. The refractive index difference is shown to change by about 0.001, representing a numerical aperture change of about 10%, over a fiber length of less than 20 m. The lowest attenuation measured from the present longitudinally-graded fiber (LGF) was 82 dB/km at a wavelength of 1550 nm, though this is shown to result from extrinsic process-induced factors and could be reduced with further optimization. The stimulated Brillouin scattering (SBS) spectrum from the LGF exhibited a 4.4 dB increase in the spectral width, and thus reduction in Brillouin gain, relative to a standard commercial single mode fiber, over a fiber length of only 17 m. The method employed is very straight-forward and provides for a wide variety of longitudinal refractive index and acoustic velocity profiles, as well as core shapes, which could be especially valuable for SBS suppression in high-energy laser systems. Next generation analogs, with longitudinally-graded compositional profiles that are very reasonable to fabricate, are shown computationally to be more effective at suppressing SBS than present alternatives, such as externally-applied temperature or strain gradients.

Evert, A.; James, A.; Hawkins, T.; Foy, P.; Dong, L.; Stolen, R.; Ballato, J.; Dragic, P.; Rice, R.

2013-03-01

173

Self-pumped phase-conjugate fiber-optic gyro.  

UK PubMed Central (United Kingdom)

We describe a new type of phase-conjugate fiber-optic gyro that uses self-pumped phase conjugation. The selfpumped configuration is simpler than externally pumped configurations and permits the use of sensing fibers longer than the coherence length of the laser. A proof-of-principle demonstration of rotation sensing with the device is presented.

McMichael I; Yeh P

1986-10-01

174

A fiber-optic sensor for the ground vibration detection  

Science.gov (United States)

This study presents a fiber-optic sensor that senses ground vibrations generated by impact of rocks upon the ground. The vibration sensor of fiber-optic interferometer consists of an amplified spontaneous emission (ASE) light source, isolator, coupler, polarization controller, vibration-sensitized fiber-optic coil, and photo detector. Both laboratory experiments and field tests were carried out to compare ground vibration signals detected simultaneously by the fiber-optic sensor and a geophone. Experimental data indicates that ground vibration signals detected by the fiber-optic sensor is similar to that detected by the traditional geophone in the frequency spectrum ranges from 10 to 250 Hz. Results of this study thus demonstrate the feasibility of this fiber-optic sensor for sensing ground vibrations produced by rock motions or other natural hazards.

Liang, Tsair-Chun; Lin, Yung-Li

2013-10-01

175

Colorimetric sensor based on two optical fiber couplers  

Science.gov (United States)

The aim of the paper is to present an idea of a low-cost optical fiber colorimetric pH sensor (with disposable probe). Most of colorimetric sensors consist of two fibers: the illuminating one and one for collecting reflected light. Only one optical fiber is used as a sensing probe in our pH sensor. The end of the fiber is covered by a pH-sensing membrane, which is made of polyvinyl chloride. The colorimetric indicator (bromothymol blue) was immobilized on an ion- exchange resin. The sensing fiber is connected with two optical fiber couplers (type Y). The first coupler guides analytical and reference wavelengths from the light emitting diodes (LED) and the second one transmits light to the photodetector. Only one photodetector is used. Optical signals are filtered electronically because the LEDs are modulated at different frequencies. The results of the measuring tests of the sensor are presented.

Dybko, Artur; Maciejewski, Janusz; Romaniuk, Ryszard S.; Wroblewski, Wojciech

1994-02-01

176

Optical fiber placement for crossover-free fiber optic gyros  

Science.gov (United States)

Fiber Optic Gyro (FOG) coils have traditionally been produced by cylindrical winding techniques. Regardless of the type of cylindrical wind, standard or quadrupolar, the resulting coils contain fiber crossovers that degrade performance. In 1998, the U.S. Army patented a fiber coil configuration that essentially eliminated crossovers, was thermally symmetric, and allowed the use of inexpensive single-mode (SM) fiber. The crossover-free fiber optic gyro (CFOG) necessitated a paradigm shift in coil production methodology. The CFOG coil design was analyzed in depth to determine manufacturability. Design enhancements were made to enable automated high speed fabrication, resulting in the Improved Crossover-free Fiber Optic Gyro (ICFOG). A prototype Fiber Placement Machine (FPM) was designed and constructed to produce CFOG coils. The fiber placement concept was verified by producing test articles and complete coils.

Williams, Marty

2006-09-01

177

Fiber-optic seismic sensor  

International Nuclear Information System (INIS)

[en] A vibration sensor is constructed by providing two preferably matched coils of fiber-optic material. When the sensor experiences vibration, a differential pressure is exerted on the two fiber coils. The differential pressure results in a variation in the relative optical path lengths between the two fibers so that light beams transmitted through the two fibers are differently delayed, the phase difference therebetween being a detectable indication of the vibration applied to the sensor

1985-01-01

178

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

Science.gov (United States)

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.

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

2013-10-01

179

System for testing optical fibers  

Energy Technology Data Exchange (ETDEWEB)

A system for measuring a combination of optical transmission properties of fiber optic waveguides. A polarized light pulse probe is injected into one end of the optical fiber. Reflections from discontinuities within the fiber are unpolarized whereas reflections of the probe pulse incident to its injection remain polarized. The polarized reflections are prevented from reaching a light detector whereas reflections from the discontinuities reaches the detector.

Golob, John E. (Olathe, KS); Looney, Larry D. (Los Alamos, NM); Lyons, Peter B. (Los Alamos, NM); Nelson, Melvin A. (Santa Barbara, CA); Davies, Terence J. (Santa Barbara, CA)

1980-01-01

180

Optical Sensors Based on Plastic Fibers  

Directory of Open Access Journals (Sweden)

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.

Lúcia Bilro; Nélia Alberto; João L. Pinto; Rogério Nogueira

2012-01-01

 
 
 
 
181

Hybrid plasmonic terahertz fibers for sensing applications  

CERN Multimedia

A novel plasmonic THz fiber featuring two metallic wires in a porous dielectric cladding is studied for resonant sensing applications. In our design, introduction of even lossless analytes into the fiber core leads to significant changes in the modal losses, which is used as a transduction mechanism.

Markov, Andrey

2013-01-01

182

Fiber Optic Oscilloscope Probe  

Energy Technology Data Exchange (ETDEWEB)

In the recent development of high voltage solid state pulsed power systems, the ability to monitor low voltage signals in a high voltage environment has been a problem. The amplitude of any ground bounce from the high voltage pulse can make the interpretation of low voltage diagnostic signals difficult with industry standard probes. The paper explains the development of a fiber optic voltage probe for the oscilloscope. Included are explanations of the probe's design, fabrication, limitations, and performance when compared with standard probes in a high voltage pulsed power environment.

Lee, B L

2001-06-11

183

Stress Sensing by an Optical Fiber Sensor: Method and Process for the Characterization of the Sensor Response Depending on Several Designs  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper we propose an analyzing of the response of a stress optical fiber sensor of which we proposed several design. We show that an optical fiber sensor with these designs can covenanting allow the measuring the force/stress applied to a mechanical structure or which it is linked, by optimizing the uses of appropriate materials for constituting the sensor support. The experiment that we introduce to validate our approach based in principles includes design with a support bearing a multimode optical fiber organized in such a way that the transmitted light is attenuated when the fiber-bending angle coming from stitching in holes of the support is modified by the effects of the force/stress applied to the optical fiber sensor realized in this way. The tests realized concern the most relevant parameters that define the performances of the stress sensor that we propose. We present the problems that we to solved for the optimization of the sensor for selecting the more efficient material for the optical fiber sensor support related to a relevant choice of optical fibers.

Mustapha Remouche; Francis Georges; Patrick Meyrueis

2013-01-01

184

Fabrication of Optical Fiber Devices  

Science.gov (United States)

In this paper we present the main research activities of the Laboratorio de Fibras Opticas del Instituto de Ciencia de los Materiales de la Universidad de Valencia. We show some of the main results obtained for devices based on tapered fibers, fiber Bragg gratings, acousto-optic effects and photonic crystal fibers.

Andres, Miguel V.

185

Fiber optic gyros and systems  

Science.gov (United States)

Fiber Optic Gyroscopes have emerged from the engineering laboratories and come into production. Conventional gyros will be replaced by the fiber optical gyros in most applications in the near future. LITEF has developed a family of gyros and systems based on these gyros. The introduction of the new technology brings many advantages with respect to function, performance, size and weight.

Bueschelberger, H.-J.; Handrich, E.

1992-11-01

186

Optical fiber powered pressure sensor  

International Nuclear Information System (INIS)

[en] In the system described, a pressure sensor and its associated electronics are optically powered by a 20 mw laser and a photovoltaic cell via an optical fiber. The sensor is periodically interrogated and sends the measures obtained back to the central unit using an LED and a second fiber. The results obtained as well as the expected evolution will be described

1987-04-03

187

Fiber-Optic Acoustic Sensor.  

Science.gov (United States)

An optical fiber acoustical sensor for detecting sound waves in a fluid medium is described. An optical fiber coil through which a light beam is transmitted is placed in a fluid medium. A sound wave propagating through the fluid medium and incident on the...

J. A. Bucaro E. F. Carome H. D. Dardy

1979-01-01

188

Python fiber-optic seal  

Energy Technology Data Exchange (ETDEWEB)

Sandia National Laboratories (SNL) has developed a high-security fiber-optic seal that incorporates tamper-resistance features not available in commercial fiber-optic seals. The Python Seal is a passive fiber-optic loop seal designed to give indication of unauthorized entry. The seal includes a fingerprint feature that provides seal identity information in addition to the unique fiber-optic pattern created when the seal is installed. The fiber-optic cable used for the seal loop is produced with tamper-resistant features that increase the difficulty of attacking this component of a seal. A Seal Reader has been developed that records the seal signature and the fingerprint feature of the seal. A Correlator software program compares seal images to establish a match or mismatch. SNL also is developing a Polaroid Reader to permit hard copies of the seal patterns to be obtained directly from the seal.

Ystesund, K.; Bartberger, J.; Brusseau, C.; Fleming, P.; Insch, K.; Tolk, K. [Sandia National Labs., Albuquerque, NM (United States)

1993-12-31

189

Fiber optics installer and technician guide  

CERN Document Server

For years, fiber optics was the future. Now, it's the present, and the time has come to act if you want to make a career in this fast-growing field. The Fiber Optics Installer and Technician Guide is a comprehensive resource designed to prepare you for the two leading fiber optics certifications, Fiber Optics Installer (FOI) and Fiber Optics Technician (FOT). This book's practical, objective-focused coverage includes:The history of fiber opticsPrinciples of fiber optic transmissionOptical fiber characteristics, construction, and theorySafety considerationsCables, connec

Woodward, Bill

2006-01-01

190

Optical fiber inspection system  

Energy Technology Data Exchange (ETDEWEB)

A remote optical inspection system including an inspection head. The inspection head has a passageway through which pellets or other objects are passed. A window is provided along the passageway through which light is beamed against the objects being inspected. A plurality of lens assemblies are arranged about the window so that reflected light can be gathered and transferred to a plurality of coherent optical fiber light guides. The light guides transfer the light images to a television or other image transducer which converts the optical images into a representative electronic signal. The electronic signal can then be displayed on a signal viewer such as a television monitor for inspection by a person. A staging means can be used to support the objects for viewing through the window. Routing means can be used to direct inspected objects into appropriate exit passages for accepted or rejected objects. The inspected objects are advantageously fed in a singular manner to the staging means and routing means. The inspection system is advantageously used in an enclosure when toxic or hazardous materials are being inspected.

Moore, Francis W. (Richland, WA)

1987-01-01

191

Fiber optic hydrogen sensor  

Energy Technology Data Exchange (ETDEWEB)

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).

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

1996-05-01

192

Impact of seasonal variability and monitoring mode on the adequacy of fiber-optic distributed temperature sensing at aquifer-river interfaces  

Science.gov (United States)

Fiber-optic distributed temperature sensing (FO-DTS) has been frequently applied for analyzing thermal patterns, including the identification of groundwater-surface water exchange fluxes across aquifer-river interfaces. However, the impacts of (a) seasonal variability in signal strength (given by the difference between groundwater and surface water temperatures) and (b) monitoring modes on the accuracy of FO-DTS surveys have not yet been determined. This study uses a well-investigated field site as model system for quantifying the accuracy and uncertainty of FO-DTS surveys in dependency of seasonal signal variation and monitoring mode. The analysis of the relationship between seasonal variability in signal strength and diurnal oscillations in end-member temperatures at the study site revealed that winter conditions, with substantially lower diurnal temperature oscillations, provide the highest temporal stability in signal strength. The choice of monitoring mode proved to have significant impact on the accuracy of FO-DTS surveys. The proposed two-way single-ended averaging of FO-DTS surveys had significant advantages compared to single-ended or double-ended surveys, with a higher accuracy in signal detection, in particular for small-scale temperature variations. Since FO-DTS surveys in two-way single-ended averaging mode were better suited for detecting the full complexity of spatial temperature patterns for the investigated aquifer-river interface, we recommend its wider application in similarly complex systems with small-scale thermal patterns.

Krause, Stefan; Blume, Theresa

2013-05-01

193

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

Directory of Open Access Journals (Sweden)

Full Text Available 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, we review two kinds of typical in-line fiber optic interferometers formed in single-mode fibers fabricated with different post-processing techniques. Also, some recently reported specific technologies for fabricating such fiber optic interferometers are presented.

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

2012-01-01

194

Fiber-optic fluorescence imaging  

Science.gov (United States)

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-based fluorescence imaging was mainly limited to epifluorescence and scanning confocal modalities. Two new classes of photonic crystal fiber facilitate ultrashort pulse delivery for fiber-optic two-photon fluorescence imaging. An upcoming generation of fluorescence imaging devices will be based on microfabricated device components.

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

2010-01-01

195

Classification of Fiber Optical Sensors  

Directory of Open Access Journals (Sweden)

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.

Shivang Ghetia; Ruchi Gajjar; Pujal Trivedi

2013-01-01

196

Scintillator fiber optic long counter  

Energy Technology Data Exchange (ETDEWEB)

A flat response position sensitive neutron detector capable of providing neutron spectroscopic data utilizing scintillator fiber optic filaments embedded in a neutron moderating housing having an open end through which neutrons enter to be detected.

McCollum, Tom (Sterling, VA); Spector, Garry B. (Fairfax, VA)

1994-01-01

197

Fiber Optic Cable Flammability Performance.  

Science.gov (United States)

Tight buffered fiber optic cables were made using a number of different materials and subjected to flame testing. The results show that different materials and combinations of materials do not perform equally. The best flame resistance was obtained when t...

D. R. Maack J. B. Masterson W. M. Kachmar

1986-01-01

198

Fiber-optic temperature sensor  

Energy Technology Data Exchange (ETDEWEB)

Researchers at the Savannah River Technology Center (SRTC) have developed a class of fiber-optic temperature sensors based upon temperature induced changes in the absorption spectrum of selected materials. For example, a neodymium (Nd) doped glass sensor can be used over a very broad temperature range ({minus}196 to 500{degree}C) and provide good precision and accuracy ({plus_minus}1{degree}C). This type temperature probe is constructed so that light from a fiber optic cable shines through the Nd glass and is reflected onto a second fiber optic cable. Light from this second fiber optic is measured by a diode array spectrophotometer, and the absorption spectrum of the Nd glass used to compute temperature.

O`Rourke, P.E.; Livingston, R.R.; Jantzen, C.M.; Ramsey, W.G.; Hopkins, C.D.

1993-10-01

199

Fiber Optic Cable Furcation Unit.  

Science.gov (United States)

A low cost rugged sealed fiber optic cable furcation unit is provided. The furcation unit has an outer heat shrink tube which encloses a protective tube. Within the protective tube, a spacer/fiber guide is located along with a sealant material. When insta...

G. D. Brown

1997-01-01

200

Fiber optic refractive index monitor  

Energy Technology Data Exchange (ETDEWEB)

A sensor for measuring the change in refractive index of a liquid uses the lowest critical angle of a normal fiber optic to achieve sensitivity when the index of the liquid is significantly less than the index of the fiber core. Another embodiment uses a liquid filled core to ensure that its index is approximately the same as the liquid being measured.

Weiss, Jonathan David (Albuquerque, NM)

2002-01-01

 
 
 
 
201

System for testing optical fibers  

Energy Technology Data Exchange (ETDEWEB)

A system for nondestructively determining the attenuation coefficient, .alpha.(.lambda.), of low-loss optical fiber wave guides. Cerenkov light pulses are generated at a plurality of locations in the fiber by a beam of charged particles. The transit times of selected spectral components and their intensities are utilized to unfold the .alpha.(.lambda.) values over the measured spectrum.

Davies, Terence J. (Santa Barbara, CA); Franks, Larry A. (Santa Barbara, CA); Nelson, Melvin A. (Santa Barbara, CA)

1981-01-01

202

Spliceless optical fiber resonant ring laser gyroscopic system  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a spliceless optical-fiber resonant-ring laser gyroscopic system, comprising: a housing having an ultra-low coefficient of thermal expansion; a selected length of optical-fiber mounted by coiling to the housing to provide an optical-fiber ring having at least one turn, the axis of the ring defining a rotation sensing direction; an evanescent-wave directional coupler provided along a localized common contiguous region proximate the ends of the optical-fiber to provide a spliceless optical-fiber ring; first means connected to the housing and coupled to the ends of the optical-fiber for selectively exciting the spliceless optical-fiber ring alternately in a clockwise and in a counterclockwise resonant mode; and second means coupled to the spliceless optical-fiber resonant-ring and operative in response to the clockwise and counterclockwise resonant modes for providing a signal indication of the rate of angular rotation of the housing about the sensing direction.

Coate, G.T.; Coccoli, J.D.

1987-07-07

203

Light diffusing fiber optic chamber  

Energy Technology Data Exchange (ETDEWEB)

A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

Maitland, Duncan J. (Lafayette, CA)

2002-01-01

204

Fracture analysis of optical fibers  

Energy Technology Data Exchange (ETDEWEB)

The fracture markings on glass optical fiber surfaces are quantitatively related to the strength and time under load. Knowledge of the fracture-initiating defects and the surrounding topography pinpoints the source of failure, aids in troubleshooting, and improves production procedures. It is shown that the techniques of fracture surface analysis help analyze in-service failures as well as improve fiber optic production control.

Mecholsky, J.J.

1980-01-01

205

Fracture analysis of optical fibers  

International Nuclear Information System (INIS)

The fracture markings on glass optical fiber surfaces are quantitatively related to the strength and time under load. Knowledge of the fracture-initiating defects and the surrounding topography pinpoints the source of failure, aids in troubleshooting, and improves production procedures. It is shown that the techniques of fracture surface analysis help analyze in-service failures as well as improve fiber optic production control.

1980-03-27

206

Phase-nulling fiber-optic laser gyro.  

UK PubMed Central (United Kingdom)

A fiber-optic gyro is described that employs closed-loop phase compensation. Preliminary experimental results are reported of the sensing of rotation rates down to 0.5 degrees /sec for a 135-mm-radius, 100-m-length fiber coil.

Cahill RF; Udd E

1979-03-01

207

Quasi-distributed long-gauge fiber optic sensor system  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Linec, Matjaž; Ðonlagi?, Denis

208

Nonlinear effects in optical fibers  

CERN Multimedia

This book will provide insight into the principles and applications of nonlinear effects in fibers for students, researchers, and developers who have a basic understanding of electromagnetic theory under their belts.  It will explore the physics, limitations, applications, and research results surrounding nonlinear effects in fiber optics. In addition to communications, optical fibers are already used in medical procedures, automobiles, and aircraft and are expected to have many other applications.  This will expand the range of industry workers who will find a book of this type useful.

Ferreira, Mario F

2011-01-01

209

A fiber-optic polarimetric demonstration kit  

International Nuclear Information System (INIS)

A simple and multifunctional fiber-optic polarimetric kit on the basis of highly birefringent single-mode fibers is presented. The fiber-optic polarimetric kit allows us to perform the following laboratory exercises: (i) fiber excitation and the measurement of numerical aperture, (ii) polarization preservation and (iii) obtain polarization-sensitive fiberized interferometers.

2012-01-01

210

Remote sensing: optics and optical systems  

Energy Technology Data Exchange (ETDEWEB)

The foundation for those wishing to pursue applications in remote sensing in which optical techniques and sensors are employed is provided. It is appropriate to the student, at or beyond the first year graduate level, who needs information on the basic optical considerations of remote sensing. It also provides detailed information for the researcher and engineer involved in spectroradiometric measurement and calibration procedures, instrumentation theory, modeling of the interactions of radiant flux with the earth's atmosphere and surface, characteristics of film and electro-optical detectors, and design and performance of optical remote sensing systems. Calculations provide examples of how various concepts are reduced to practice. There are examples involving the radiative transfer from a point or a surface to a surface; radiometric-to-photometric conversions; and the radiometry of the mirror beacon experiment. Calculations are made to compare the performances of prism, grating, Fabry-Perot, and Fourier transform spectrometers and to compare the information capacities of photographic film and magnetic tape. Signal-to-noise ratio analyses are carried out for systems using different types of electro-optical detectors. The feasibility of an orbital Fraunhofer line discriminator is considered from the standpoint of system signal-to-noise ratio. A comparison is described between the signal-to-noise ratios of imagery produced by linear array and film systems having the same image-forming optics. An appendix deals with the calculation of the number of pixels and the telemetry requirements for a Landsat scene.

Slater, P.N.

1980-01-01

211

Optical fiber communications cable connector  

Science.gov (United States)

A six channel hermaphroditic connector, which will function with 125 micron to 150 micron diameter optical fibers, was designed, constructed, and tested. The principal aspects of design, including the incorporation of the TRW Cinch Optalign 'double elbow' fiber alignment guide concept are included. Means for connecting either Siecor or ITT six fiber cable were developed. The use of ITT cable required the development of methods for stripping the jacket and buffer layer from each fiber, and applying a protective trimethylchlorosilane coating to retain inherent glass fiber strength. The rapid and simple connector assembly procedures for the final model are described, as well as the unique fiber scribe and cleave tool which was designed specifically for use with this connector. Typical insertion loss levels obtained with the ITT cable are approximately 1.0 dB, seldom greater than 1.5 dB. The results of vibration, thermal shock and mating durability tests are discussed.

Woods, J. G.

1981-07-01

212

Assembly and Method for Furcating Optical Fibers.  

Science.gov (United States)

An assembly that includes a fiber-containing structure that contains a plurality of optical fibers and a furcation tube assembly that includes a plurality of loose tube optical fiber cables. Each of the loose tube optical fiber cables includes a hollow in...

D. Brown Y. T. Jeleniewski R. A. Throm

1999-01-01

213

Fiber optic spectrochemical emission sensors  

International Nuclear Information System (INIS)

Prior work on fiber optic spectrochemical emission sensor (FOSES) concepts has been extended to the design and fabrication of a prototype fiber optic chemical sensor system for chlorinated compounds. The sensor performs analyte dissociation and atomic excitation via a radio-frequency-excited helium plasma. The device has been configured for field measurements of vadose-zone concentrations of carbon tetrachloride on the Hanford Reservation in southeastern Washington state. Detection and quantification of other atomic species may be achieved by varying the analytical wavelength. The sensor system design incorporates and RF excitation source: a metered, sub-atmospheric pressure helium supply system; and optical detection system; and a fiber optic umbilical to transmit analyte emissions to a central detection/data acquisition system. Sensor system design is summarized as well as performance data relating to detection limits and dynamic range

1989-01-01

214

Online fiber-optic photometer  

Energy Technology Data Exchange (ETDEWEB)

The development and implementation of a fiber-optic photometer for process control at the Savannah River Plant (SRP) will be discussed. The instrument is a modified Du Pont 400 photometric analyzer which incorporates quartz fiber-optic cables, a high-intensity tungsten-halogen lamp source, and a sight glass with sealed optics. Six of these photometers have been installed at SRP to monitor the elution of neptunium or plutonium from anion exchange columns. The fiber optics allow the instrument to be located 50 feet from the sight glass, which is in a highly radioactive area. This ensures easy access to the instrument and minimizes radiation exposure to personnel. The modifications to the analyzer and its application to process control will be presented.

Van Hare, D.R.; Prather, W.S.; Boyce, D.A.; Spencer, W.A.

1985-01-01

215

A fiber-optic current sensor for aerospace applications  

Energy Technology Data Exchange (ETDEWEB)

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.

Patterson, R.L. [Lewis Research Center, Cleveland, OH (United States); Rose, A.H.; Tang, D.; Day, G.W. [National Institute of Standards and Technology, Boulder, CO (United States)

1994-09-01

216

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

Directory of Open Access Journals (Sweden)

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).

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

2009-01-01

217

A fiber optic wind vane  

Energy Technology Data Exchange (ETDEWEB)

A Cooperative Research and Development Agreement (CRADA) between Met One Instruments, Incorporated (Met One) and Westinghouse Savannah River Company (WSRC) was made to develop and test a fiber optic measurement-based wind vane. Some advantages of using fiber optic technology for a wind vane include protection against lightning-induced electrical surges and radio-frequency interference, suitability for use in explosive environments, and a longer field life. A prototype fiber optic wind vane was built by Met One and tested by WSRC. Wind tunnel test results indicated that the vane is very sensitive to low wind speeds (< 0.15 meter per second) although the resolution of the sensor (1.4 degrees) is higher than typical wind vanes. A side-by-side field test with a conventional commercial wind vane indicated that the fiber optic wind vane performed well and even outperformed the conventional sensor during low wind speed conditions. The field test also indicated that the fiber optic sensor is a viable instrument although some modifications are required before the sensor can be readily commercialized.

Parker, M.J.; Heverly, M.

1997-02-01

218

Integrating fiber optic radiation dosimeter  

International Nuclear Information System (INIS)

[en] The purpose of this research effort was to determine the feasibility of forming a radiation sensor coupled to an optical fiber capable of measuring gamma photon, x-ray, and beta particle dose rates and integrated dose, and to construct a prototype dosimeter read-out system utilizing the fiber optic sensor. The key component of the prototype dosimeter system is a newly developed radiation sensitive storage phosphor. When this phosphor is excited by energetic radiation, a proportionate population of electron-hole pairs are created which become trapped at specific impurities within the phosphor. Trapped electrons can subsequently be stimulated optically with near-infrared at approximately 1 micrometer wavelength; the electrons can recombine with holes at luminescent centers to produce a luminescence which is directly proportional to the trapped electron population, and thus to the radiation exposure. By attaching the phosphor to the end of an optical fiber, it is possible to transmit both the IR optical stimulation and the characteristic phosphor luminescence through the fiber to and from the read-out instrument, which can be located far (e.g., kilometers) from the radiation field. This document reports on the specific design of the prototype system and its operating characteristics, including its sensitivity to various radiation dose rates and energies, its dynamic range, signal-to-noise ratio at various radiation intensities, and other system characteristics. Additionally, the radiation hardness of the phosphor and fiber are evaluated. 17 refs., 29 figs., 5 tabs

1989-01-01

219

Integrating fiber optic radiation dosimeter  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this research effort was to determine the feasibility of forming a radiation sensor coupled to an optical fiber capable of measuring gamma photon, x-ray, and beta particle dose rates and integrated dose, and to construct a prototype dosimeter read-out system utilizing the fiber optic sensor. The key component of the prototype dosimeter system is a newly developed radiation sensitive storage phosphor. When this phosphor is excited by energetic radiation, a proportionate population of electron-hole pairs are created which become trapped at specific impurities within the phosphor. Trapped electrons can subsequently be stimulated optically with near-infrared at approximately 1 micrometer wavelength; the electrons can recombine with holes at luminescent centers to produce a luminescence which is directly proportional to the trapped electron population, and thus to the radiation exposure. By attaching the phosphor to the end of an optical fiber, it is possible to transmit both the IR optical stimulation and the characteristic phosphor luminescence through the fiber to and from the read-out instrument, which can be located far (e.g., kilometers) from the radiation field. This document reports on the specific design of the prototype system and its operating characteristics, including its sensitivity to various radiation dose rates and energies, its dynamic range, signal-to-noise ratio at various radiation intensities, and other system characteristics. Additionally, the radiation hardness of the phosphor and fiber are evaluated. 17 refs., 29 figs., 5 tabs.

Soltani, P.K.; Wrigley, C.Y.; Storti, G.M.; Creager, R.E.

1989-03-01

220

Drift reduction in an optical heterodyne fiber gyro.  

UK PubMed Central (United Kingdom)

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.

Hotate K; Samukawa S

1990-03-01

 
 
 
 
221

Development of a 2-Channel Embedded Infrared Fiber-Optic Temperature Sensor Using Silver Halide Optical Fibers  

Directory of Open Access Journals (Sweden)

Full Text Available A 2-channel embedded infrared fiber-optic temperature sensor was fabricated using two identical silver halide optical fibers for accurate thermometry without complicated calibration processes. In this study, we measured the output voltages of signal and reference probes according to temperature variation over a temperature range from 25 to 225 °C. To decide the temperature of the water, the difference between the amounts of infrared radiation emitted from the two temperature sensing probes was measured. The response time and the reproducibility of the fiber-optic temperature sensor were also obtained. Thermometry with the proposed sensor is immune to changes if parameters such as offset voltage, ambient temperature, and emissivity of any warm object. In particular, the temperature sensing probe with silver halide optical fibers can withstand a high temperature/pressure and water-chemistry environment. It is expected that the proposed sensor can be further developed to accurately monitor temperature in harsh environments.

Wook Jae Yoo; Kyoung Won Jang; Jeong Ki Seo; Jinsoo Moon; Ki-Tek Han; Jang-Yeon Park; Byung Gi Park; Bongsoo Lee

2011-01-01

222

Multimode optical fiber based spectrometers  

CERN Multimedia

A standard multimode optical fiber can be used as a general purpose spectrometer after calibrating the wavelength dependent speckle patterns produced by interference between the guided modes of the fiber. A transmission matrix was used to store the calibration data and a robust algorithm was developed to reconstruct an arbitrary input spectrum in the presence of experimental noise. We demonstrate that a 20 meter long fiber can resolve two laser lines separated by only 8 pm. At the other extreme, we show that a 2 centimeter long fiber can measure a broadband continuous spectrum generated from a supercontinuum source. We investigate the effect of the fiber geometry on the spectral resolution and bandwidth, and also discuss the additional limitation on the bandwidth imposed by speckle contrast reduction when measuring dense spectra. Finally, we demonstrate a method to reduce the spectrum reconstruction error and increase the bandwidth by separately imaging the speckle patterns of orthogonal polarizations. The mu...

Redding, Brandon; Cao, Hui

2013-01-01

223

Optical fibers and solar energy  

Energy Technology Data Exchange (ETDEWEB)

The possibilities for the use of optical fibers for the transmission of solar energy from the focus of a solar concentrator to a device for solar energy utilization are considered. The transmittance properties of currently available optical fibers are shown to be suitable for solar energy transmission, and a device for the coupling of focused solar energy into an optical fiber is presented which is based on the use of a mirror providing an image of the sun coinciding with the entrance end of a single light conductor. The integration of many such modules, each with a maximum output power of about 2W, may be used in applications such as solar furnaces for hydrogen production, photovoltaic energy conversion or thermal electricity generation.

Dugas, J.; Cariou, J.M.; Martin, L.

1982-01-01

224

Optical sensor based on two in-series birefringent optical fibers.  

UK PubMed Central (United Kingdom)

An optical fiber sensor based on the combination of two spliced birefringent optical fiber sections is proposed in this paper. The sensor is built up in a Solc-filter-like configuration and a simple theoretical model based on Jones matrices is employed to predict experimental results. By choosing the suitable birefringent optical fibers (e.g., photonic crystal fibers, birefringent microfibers, elliptical core fibers, PANDA fibers, etc.), the sensor described herein allows for probing of two physical parameters (e.g., refractive index and temperature, hydrostatic pressure and temperature) or sensing the same parameter in two disconnected environments. In order to demonstrate the sensor performance, the system response was evaluated in a temperature-sensing measurement.

Osório JH; Cordeiro CM

2013-07-01

225

Development of a fiber optical torquemeter  

Science.gov (United States)

In this paper, a fiber optical torquemeter which is suitable for on-line monitoring the turning moment of a drill turntable is researched. The meter consists of a fiber optical Mach-Zehnder interferometer, a signal processor and a monitor. The fiber optical Mach-Zehnder interferometer is formed with a signal and a reference optical fiber arms, two 3dB couplers, a GaAs LD and two photoelectric probers. Both the signal optical fiber arm and reference optical fiber arm are made with polarization maintaining optical fibers. The signal optical fiber arm is made with a shearing elastic tube-shaped object, and a polarization maintaining optical fiber is would upon it. Both ends of the shearing elastic tube-shaped object is fixed upon an axis being measured. The shearing strain of the axis will make the size of the signal optical fiber change, and in this way the phase of the light wave in the optical fiber is modulated between the signal optical fiber arm and the reference optical fiber arm. By measuring the phase change with probers, the shearing strain of the axis is known, and the turning moment is obtained. The signal is processed by MCS-51. The result is shown by the monitor.

Wang, Xiwen; Chen, Yaosheng

1996-12-01

226

Subwavelength and nanometer diameter optical fibers  

CERN Multimedia

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

Tong, Limin

2011-01-01

227

Fiber optic moisture sensor with moisture-absorbing reflective target  

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus for sensing moisture changes by utilizing optical fiber technology. One embodiment uses a reflective target at the end of an optical fiber. The reflectance of the target varies with its moisture content and can be detected by a remote unit at the opposite end of the fiber. A second embodiment utilizes changes in light loss along the fiber length. This can be attributed to changes in reflectance of cladding material as a function of its moisture content. It can also be affected by holes or inserts interposed in the cladding material and/or fiber. Changing light levels can also be coupled from one fiber to another in an assembly of fibers as a function of varying moisture content in their overlapping lengths of cladding material.

Kirkham, Randy R. (Richland, WA)

1987-01-01

228

A Smart Graded-index Multimode Fiber Based Sensor Unit for Multi-parameter Sensing Applications  

Directory of Open Access Journals (Sweden)

Full Text Available We demonstrate a smart optical fiber sensor unit to realize a multi-parameter sensing, including temperature, curvature and strain or displacement. The sensor unit is composed of a Bragg grating in graded-index multimode fiber and a Fizeau cavity.

Shuo Fang; Baoyong Li; Dawei Song; Jianzhong Zhang; Weimin Sun; Libo Yuan

2013-01-01

229

Fiber optic and laser sensors III  

International Nuclear Information System (INIS)

[en] Fiber Optic and Laser Sensors III is the third of a planned series of conferences dealing with state-of-the-art advancement in this technology area. Historically this conference has evolved due to the pioneering work aimed at acoustic and rotation sensing at several government and university laboratories (e.g., Naval Research Laboratory, MIT, and Stanford). At this point, if it can be sensed (temperature, magnetic field, blood pressure, rotation, flow, liquid level, current, voltage, gas and liquid chemistry, etc.) someone is trying to do it with fibers; many of these activities are recorded in this publication. A new activity, broadband sensors, was introduced at this conference; the major thrust is to use the large bandwidth of the optical fiber and conventional sensor to record single occurrence events (e.g., a nuclear explosion). Other important areas of presentation were: stress in composites, distributed sensors, and sensors for biological/medical applications. Although several papers were presented by major industrial companies related to the continuing development of the rotation sensor, the participation was limited by the evolution toward products, a natural path (as new technology progresses research and development become specific to proprietary designs)

1985-01-01

230

Recent Progress in Distributed Fiber Optic Sensors  

Directory of Open Access Journals (Sweden)

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.

Xiaoyi Bao; Liang Chen

2012-01-01

231

Evanescent-wave infrared spectroscopy with flattened fibers as sensing elements.  

UK PubMed Central (United Kingdom)

Fiber-optic evanescent-wave spectroscopy (FEWS) is a novel method for measuring the absorption spectra of samples in contact with a segment of an optical fiber that serves as a sensing element. We used a cylindrical IR-transmitting AgClBr fiber whose central section, of length L, was flattened to a thickness d. This section was used as the FEWS sensing element. Our theoretical work predicted that the signals obtained in FEWS measurements should be linearly dependent on L and inversely proportional to d. Decreasing the thickness can significantly increase its sensitivity of the sensor. These theoretical results were verified experimentally by measurements of methanol and water.

Raichlin Y; Fel L; Katzir A

2003-12-01

232

Fiber-optical microphones and accelerometers based on polymer optical fiber Bragg gratings : [invited  

DEFF Research Database (Denmark)

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, using 325nm UV writing and a phase-mask technique. 6mm POF sections with FBGs in the center have been glued to standard Silica SMF28 fibers. These POF FBGs have been characterized in terms of temperature and strain to find operating regimes with no hysteresis. Commercial fast wavelength interrogators (KHz) are shown to be able to track the thin POF FBGs and they are finally applied in a prototype accelerometer. The specs are compared to the specs obtained when using Silica FBGs.

Yuan, Scott Wu Technical University of Denmark,

2010-01-01

233

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

DEFF Research Database (Denmark)

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.

Emiliyanov, Grigoriy Andreev; HØiby, Poul E.

2013-01-01

234

Selective serial multi-antibody biosensing with TOPAS microstructured polymer optical fibers.  

UK PubMed Central (United Kingdom)

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.

Emiliyanov G; Høiby PE; Pedersen LH; Bang O

2013-01-01

235

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

Directory of Open Access Journals (Sweden)

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.

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

2013-01-01

236

Applications of fiber optics in physical protection  

Energy Technology Data Exchange (ETDEWEB)

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.

Buckle, T.H. [Sandia National Labs., Albuquerque, NM (United States)

1994-03-01

237

Sealed fiber-optic bundle feedthrough  

Energy Technology Data Exchange (ETDEWEB)

A sealed fiber-optic bundle feedthrough by which a multitude of fiber-optic elements may be passed through an opening or port in a wall or structure separating two environments at different pressures or temperatures while maintaining the desired pressure or temperature in each environment. The feedthrough comprises a rigid sleeve of suitable material, a bundle of individual optical fibers, and a resin-based sealing material that bonds the individual optical fibers to each other and to the rigid sleeve.

Tanner, Carol E. (Niles, MI)

2002-01-01

238

Catching Attention in Fiber Optics Class  

CERN Multimedia

Following a brief review on the history and the current development of fiber optics, the significance of teaching fiber optics for science and non-science major college students is addressed. Several experimental demonstrations designed to aid the teaching and learning process in fiber optics lectures are presented. Sample laboratory projects are also proposed to help the students to understand the physical principles of fiber optics.

Kezerashvili, G Ya

2004-01-01

239

Flexible Optical Waveguide Bent Loss Attenuation Effects Analysis and Modeling Application to an Intrinsic Optical Fiber Temperature Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available The temperature dependence of the bending loss light energy in multimode optical fibers is reported and analyzed. The work described in this paper aims to extend an initial previous analysis concerning planar optical waveguides, light energy loss, to circular optical waveguides. The paper also presents à novel intrinsic fiber optic sensing device base on this study allowing to measure temperatures parameters. The simulation results are validated theoretically in the case of silica/silicone optical fiber. A comparison is done between results obtained with an optical fiber and the results obtained from the previous curved optical planar waveguide study. It is showed that the bending losses and the temperature measurement range depend on the curvature radius of an optical fiber or waveguide and the kind of the optical waveguide on which the sensing process is implemented.

Mustapha Remouche; Francis Georges; Patrick Meyrueis

2012-01-01

240

FOA Lecture 1: Fiber Optics & Communications  

Science.gov (United States)

This is the first of a series of short lectures on fiber optics by Jim Hayes, president of the Fiber Optic Association. This lecture covers how fiber optics are used in various types of systems such as telecommunications, CATV, security and Smart Grid. Running time for the lecture is 12:21. Flash is required to view the video.

Hayes, Jim

2013-07-05

 
 
 
 
241

Quasi-distributed long-gauge fiber optic sensor system.  

UK PubMed Central (United Kingdom)

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.

Linec M; Donlagi? D

2009-07-01

242

Online fiber-optic spectrophotometry  

Energy Technology Data Exchange (ETDEWEB)

To improve the timeliness of chemical information and reduce the potential for personnel radiation exposure, the Savannah River Laboratory has developed online absorption spectrophotometers. Absorption spectrophotometers are rugged, precise instruments which, however, are susceptible to interference from other optically absorbing species and to changes in analyte absorbance due to different matrixes. Also, it is difficult and expensive to interface absorption spectrophotometers to SRP's radioactive processes. The fiber-optic spectrophotometer described solves these problems by combining three technologies: fiber optics, diode array spectrophotometers, and multivariate data analysis. A multiplexed fiber-optic light transmission system connects as many as ten process sample locations to a single remote spectrophotometer up to 100 meters distant. In addition to the sample locations, the spectrophotometer is also connected to reference and standard optical cells for online data validation and error checking. For each sample location, the spectrophotometer rapidly collects a series of absorption spectra from 300 to 820 nm. Spectra are tested for sample quality and integrity before analyte concentrations and residual spectra are computed from a multivariate model of the absorption characteristics of the chemical system. Residual spectra are tested to determine if any unknown interference or matrix effect may invalidate concentration results.

O' Rourke, P.E.; Van Hare, D.R.

1987-01-01

243

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

Science.gov (United States)

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.

Yang, Minghong; Li, Zhi; Dai, Jixiang; Yang, Zhi; Zhang, Yi; Zhuang, Zhi

2013-09-01

244

Fiber-optic color synthesizer.  

UK PubMed Central (United Kingdom)

Full-color synthesis was achieved, for what we believe is the first time, utilizing a novel 3x1 hard polymer-clad fiber coupler along with red, green, and blue (RGB) LED primaries. By using RGB LEDs that are coupled to three input ports, the device rendered full color from the output port with a circular emitting pixel of 135 microm in diameter with an extended color gamut. The proposed fiber-optic color synthesizer can provide a compact waveguide solution for the beam scanning display and the tunable pure white source for LED backlighting.

Jeong Y; Lee D; Lee JW; Oh K

2006-07-01

245

Artificially disordered birefringent optical fibers.  

UK PubMed Central (United Kingdom)

We develop and experimentally verify a theory of evolution of polarization in artificially-disordered multi-mode optical fibers. Starting with a microscopic model of photo-induced index change, we obtain the first and second order statistics of the dielectric tensor in a Ge-doped fiber, where a volume disorder is intentionally inscribed via UV radiation transmitted through a diffuser. A hybrid coupled-power & coupled-mode theory is developed to describe the transient process of de-polarization of light launched into such a fiber. After certain characteristic distance, the power is predicted to be equally distributed over all co-propagating modes of the fiber regardless of their polarization. Polarization-resolved experiments, confirm the predicted evolution of the state of polarization. Complete mode mixing in a segment of fiber as short as ? 10cm after 3.6dB insertion loss is experimentally observed. Equal excitation of all modes in such a multi-mode fiber creates the conditions to maximize the information capacity of the system under e.g. multiple-input-multiple-output (MIMO) transmission setup.

Herath S; Puente NP; Chaikina EI; Yamilov A

2012-02-01

246

Extrinsic fiber-optic Fabry-Perot interferometer sensor for refractive index measurement of optical glass  

Energy Technology Data Exchange (ETDEWEB)

A simple fiber-optic sensor based on Fabry-Perot interference for refractive index measurement of optical glass is investigated both theoretically and experimentally. A broadband light source is coupled into an extrinsic fiber Fabry-Perot cavity formed by the surfaces of a sensing fiber end and the measured sample. The interference signals from the cavity are reflected back into the same fiber. The refractive index of the sample can be obtained by measuring the contrast of the interference fringes. The experimental data meet with the theoretical values very well. The proposed technique is a new method for glass refractive index measurement with a simple, solid, and compact structure.

Chen Jihuan; Zhao Jiarong; Huang Xuguang; Huang Zhenjian

2010-10-10

247

Interferometric fiber optic displacement sensor  

Energy Technology Data Exchange (ETDEWEB)

A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

Farah, John (M.I.T. Branch P.O. Box 301, Cambridge, MA 02139)

1995-01-01

248

Interferometric fiber optic displacement sensor  

Energy Technology Data Exchange (ETDEWEB)

A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 29 figs.

Farah, J.

1995-05-30

249

Interferometric fiber optic displacement sensor  

Energy Technology Data Exchange (ETDEWEB)

A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

Farah, John (M.I.T. P.O. Box 397301, Cambridge, MA 02139)

1999-01-01

250

Interferometric fiber optic displacement sensor  

Energy Technology Data Exchange (ETDEWEB)

A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 23 figs.

Farah, J.

1999-04-06

251

Optical Fiber for High-Power Optical Communication  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We examined optical fibers suitable for avoiding such problems as the fiber fuse phenomenon and failures at bends with a high power input. We found that the threshold power for fiber fuse propagation in photonic crystal fiber (PCF) and hole-assisted fiber (HAF) can exceed 18 W, which is more than 10...

Kenji Kurokawa

252

Twisted and braided fiber-optic sensors in smart structures  

Energy Technology Data Exchange (ETDEWEB)

Fiber-optic based smart structures have recently become the subject of intense study in university and industrial research laboratories. A smart structure can monitor itself throughout its lifetime and provide an accurate estimate of its integrity. The sensors in smart structures must therefore be able to detect even small changes in the operating environment (like stress, temperature, chemical reaction, etc.). This paper pertains to the sensing of strain using embedded twisted and braided fibers which have a much greater sensitivity to changes in applied stress than normal fibers as a result of enhanced microbending. In addition, step-index multimode fibers were used in this research program because the ease of manufacture and lower cost of these fibers (compared to the more commonly used graded index fibers) can be significant and deciding factors in many applications. Results obtained from the experimental program confirm the concept and potential of the fibers used in this study for use in smart structures.

Mutalik, V.G.; Srinivasan, A.V.; Canistraro, H.; Roychoudhuri, C. [Univ. of Connecticut, Storrs, CT (United States); Hodge, M.

1994-12-31

253

Generalized fiber Fourier optics.  

Science.gov (United States)

A twofold generalization of the optical schemes that perform the discrete Fourier transform (DFT) is given: new passive planar architectures are presented where the 2 × 2 3 dB couplers are replaced by M × M hybrids, reducing the number of required connections and phase shifters. Furthermore, the planar implementation of the discrete fractional Fourier transform (DFrFT) is also described, with a waveguide grating router (WGR) configuration and a properly modified slab coupler. PMID:21686007

Cincotti, Gabriella

2011-06-15

254

Generalized fiber Fourier optics.  

UK PubMed Central (United Kingdom)

A twofold generalization of the optical schemes that perform the discrete Fourier transform (DFT) is given: new passive planar architectures are presented where the 2 × 2 3 dB couplers are replaced by M × M hybrids, reducing the number of required connections and phase shifters. Furthermore, the planar implementation of the discrete fractional Fourier transform (DFrFT) is also described, with a waveguide grating router (WGR) configuration and a properly modified slab coupler.

Cincotti G

2011-06-01

255

Asymmetrical star coupler for optical fiber systems.  

UK PubMed Central (United Kingdom)

A technique has been developed for fabricating M x N fiber couplers that use different core-size fibers to improve the interconnection efficiency of multiterminal optical fiber systems. Experimental results are described for a 2 x 8 transmissive asymmetrical star coupler using 125-microm core diam input fibers and 63-microm core diam output fibers. This construction procedure also has the important advantage of improving the fiber throughput uniformity of fused biconical taper multiport couplers.

Gravel RL; Nelson AR

1981-08-01

256

Optical fiber temperature sensors: applications in heat treatments for foods  

Science.gov (United States)

Heat treatments are important methods to provide safe foods. Conventional heat treatments involve the application of steam and recently microwave treatments have been studied and applied as they are considered as fast, clean and efficient. Optical fiber sensing is an excellent tool to measure the temperature during microwave treatments. This paper shows the application of optical fiber temperature sensing during the heat treatment of different foods such as vegetables (jalapeño pepper and cilantro), cheese and ostrich meat. Reaching the target temperature, important bacteria were inactivated: Salmonella, Listeria and Escherichia coli. Thus, the use of optical fiber sensors has resulted be a useful way to develop protocols to inactivate microorganisms and to propose new methods for food processing.

Sosa-Morales, María Elena; Rojas-Laguna, Roberto; López-Malo, Aurelio

2010-10-01

257

Fiber Optic Pressure Sensor using Multimode Interference  

International Nuclear Information System (INIS)

[en] Based on the theory of multimode interference (MMI) and self-image formation, we developed a novel intrinsic optical fiber pressure sensor. The sensing element consists of a section of multimode fiber (MMF) without cladding spliced between two single mode fibers (SMF). The MMI pressure sensor is based on the intensity changes that occur in the transmitted light when the effective refractive index of the MMF is changed. Basically, a thick layer of Polydimethylsiloxane (PDMS) is placed in direct contact with the MMF section, such that the contact area between the PDMS and the fiber will change proportionally with the applied pressure, which results in a variation of the transmitted light intensity. Using this configuration, a good correlation between the measured intensity variations and the applied pressure is obtained. The sensitivity of the sensor is 3 ?V/psi, for a range of 0-60 psi, and the maximum resolution of our system is 0.25 psi. Good repeatability is also observed with a standard deviation of 0.0019. The key feature of the proposed pressure sensor is its low fabrication cost, since the cost of the MMF is minimal.

2011-01-01

258

Fiber Optic Pressure Sensor using Multimode Interference  

Energy Technology Data Exchange (ETDEWEB)

Based on the theory of multimode interference (MMI) and self-image formation, we developed a novel intrinsic optical fiber pressure sensor. The sensing element consists of a section of multimode fiber (MMF) without cladding spliced between two single mode fibers (SMF). The MMI pressure sensor is based on the intensity changes that occur in the transmitted light when the effective refractive index of the MMF is changed. Basically, a thick layer of Polydimethylsiloxane (PDMS) is placed in direct contact with the MMF section, such that the contact area between the PDMS and the fiber will change proportionally with the applied pressure, which results in a variation of the transmitted light intensity. Using this configuration, a good correlation between the measured intensity variations and the applied pressure is obtained. The sensitivity of the sensor is 3 {mu}V/psi, for a range of 0-60 psi, and the maximum resolution of our system is 0.25 psi. Good repeatability is also observed with a standard deviation of 0.0019. The key feature of the proposed pressure sensor is its low fabrication cost, since the cost of the MMF is minimal.

Ruiz-Perez, V I; Sanchez-Mondragon, J J [INAOE, Apartado Postal 51 y 216, Puebla 72000 (Mexico); Basurto-Pensado, M A [CIICAp, Universidad Autonoma del Estado de Morelos (Mexico); LiKamWa, P [CREOL, University of Central Florida, Orlando, FL 32816 (United States); May-Arrioja, D A, E-mail: iruiz@inaoep.mx, E-mail: mbasurto@uaem.mx, E-mail: delta_dirac@hotmail.com, E-mail: daniel_may_arrioja@hotmail.com [UAT Reynosa Rodhe, Universidad Autonoma de Tamaulipas (Mexico)

2011-01-01

259

Fiber-optic voltage sensor with cladded fiber and evanescent wave variation detection  

Energy Technology Data Exchange (ETDEWEB)

A fiber optic voltage sensor is described which includes a source of light, a reference fiber for receiving a known percentage of the light and an electrostrictive element having terminals across which is applied, a voltage to be measured. The electrostrictive element is responsive to the applied voltage to assume an altered physical state. A measuring fiber also receives a known percentage of light from the light source and is secured about the electrostrictive element. The measuring fiber is provided with a cladding and exhibits an evanescent wave in the cladding. The measuring fiber has a known length which is altered when the electrostrictive element assumes its altered physical state. A differential sensor is provided which senses the intensity of light in both the reference fiber and the measuring fiber and provides an output indicative of the difference between the intensities.

Wood, Charles B. (Lakewood, CO)

1992-01-01

260

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.

1978-09-08

 
 
 
 
261

Composite Ground Wire with Optical Fibers.  

Science.gov (United States)

The composite ground wire with optical fiber (OPT-GW) designed with a tight fiber unit shows stable characteristics through manufacturing, installation, and operation. This paper explains the structure, accessories, and performance characteristics of OPT-...

C. R. Russ N. Misono A. Okazato T. Kobayashi

1986-01-01

262

Multiplex in-cylinder pressure measurement utilizing an optical fiber with specific refractive-index composition.  

Science.gov (United States)

An approach to multiplex in-cylinder pressure measurement that utilizes a single-mode optical fiber with specific refractive-index composition has been proposed. The sensing fiber has been designed to show a certain amount of optical power loss with a small change in the fiber-local-bend radius. Along with pressure-transferring diaphragms the sensing fiber was embedded into the head gasket of a four-cylinder gasoline engine. The internal-pressure change in each combustion chamber was detected on the basis of bending power loss in the fiber. Combustion pressure peaks for each cylinder were clearly observed. PMID:21085226

Komachiya, M; Sonobe, H; Oho, S; Kurita, M; Nakazawa, T; Sasayama, T

1996-03-01

263

Multiplex in-cylinder pressure measurement utilizing an optical fiber with specific refractive-index composition.  

UK PubMed Central (United Kingdom)

An approach to multiplex in-cylinder pressure measurement that utilizes a single-mode optical fiber with specific refractive-index composition has been proposed. The sensing fiber has been designed to show a certain amount of optical power loss with a small change in the fiber-local-bend radius. Along with pressure-transferring diaphragms the sensing fiber was embedded into the head gasket of a four-cylinder gasoline engine. The internal-pressure change in each combustion chamber was detected on the basis of bending power loss in the fiber. Combustion pressure peaks for each cylinder were clearly observed.

Komachiya M; Sonobe H; Oho S; Kurita M; Nakazawa T; Sasayama T

1996-03-01

264

Engineering modes in optical fibers with metamaterial  

DEFF Research Database (Denmark)

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 as graded material properties. Therefore, incorporation of metamaterial in optical fiber designs can produce a new range of fiber properties. With a particular example, we will show how mode discrimination can be achieved in a multimode Bragg fiber with the help of metamaterial. We also look into the mean field theory as well as Maxwell-Garnett theory for homogenizing a fine metamaterial structure to a homogeneous one. The accuracies of the two homogenization approaches are compared with fullstructure calculation.

Yan, Min; Mortensen, Asger

2009-01-01

265

Temperature and refractive index sensing characteristics of an MZI-based multimode fiber-dispersion compensation fiber-multimode fiber structure  

Science.gov (United States)

We proposed an optical fiber sensor with simple multimode fiber (MMF)-dispersion compensation fiber (DCF)-multimode fiber structure based on Mach-Zehnder Interferometer (MZI) and researched its temperature and refractive index (RI) sensing characteristics. The sensing principle is based on the interference between core and cladding modes of DCF due to the large core diameter mismatch. Spectral analyses demonstrate that the transmission spectrum is mainly formed by the interference between the dominant excited cladding mode and core modes. The experimental results show that the proposed sensor has high temperature sensitivity of 0.118 nm/°C in the range of 20-250 °C and RI sensitivity of 66.32 nm/RIU within the linear sensing range of 1.33-1.39 RIU. Therefore, the characteristics of compact size, low cost, easy fabrication, high sensitivities, and good anti-interference ability make this sensor have extensive application prospects.

Sun, Hao; Yang, Shen; Zhang, Jing; Rong, Qiangzhou; Liang, Lei; Xu, Qinfang; Xiang, Guanghua; Feng, Dingyi; Du, Yanying; Feng, Zhongyao; Qiao, Xueguang; Hu, Manli

2012-12-01

266

Fiber optic neutron imaging system: calibration  

International Nuclear Information System (INIS)

Two neutron imaging experiments using fiber optics have been performed at the Nevada Test Site. In each experiment, an array of scintillator fluor tubes is exposed to neutrons. Light is coupled out through radiation resistant PCS fibers (8-m long) into high-bandwidth, graded index fibers. For image reconstruction to be accurate, common timing differences and transmission variations between fiber optic channels are needed. The calibration system featured a scanning pulsed dye laser, a specially designed fiber optic star coupler, a tektronix 7912AD transient digitizer, and a DEC PDP 11/34 computing system.

1981-08-28

267

Fiber optic neutron imaging system: calibration  

Energy Technology Data Exchange (ETDEWEB)

Two neutron imaging experiments using fiber optics have been performed at the Nevada Test Site. In each experiment, an array of scintillator fluor tubes is exposed to neutrons. Light is coupled out through radiation resistant PCS fibers (8-m long) into high-bandwidth, graded index fibers. For image reconstruction to be accurate, common timing differences and transmission variations between fiber optic channels are needed. The calibration system featured a scanning pulsed dye laser, a specially designed fiber optic star coupler, a Tektronix 7912AD transient digitizer, and a DEC PDP 11/34 computing system.

Malone, R.M.; Gow, C.E.; Thayer, D.R.

1981-01-01

268

Fiber-optical accelerometers based on polymer optical fiber Bragg gratings  

DEFF Research Database (Denmark)

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.

Yuan, Scott Wu; Stefani, Alessio

2010-01-01

269

Optical Fiber Sensor Instrumentation for Slagging Coal Gasifiers  

Energy Technology Data Exchange (ETDEWEB)

Coal gasifier is one of the most promising solutions for clean fossil energy. Refractory thickness monitoring and online real-time temperature measurement is needed for improved reliability and advanced process control for current and future generation power plants. The objective of this program is to design and implement an optical fiber based sensing system that could potentially be used to monitor refractory wall thickness and temperature inside a coal gasifier. For the thickness monitoring, the system should be able to operate at temperatures up to 1000 C. For this temperature range, silica fiber can still work so it is chosen for the sensor design. The measurement is based on a photon counting optical time domain reflectometer. A narrow light pulse is launched into a silica fiber which could be embedded into the gasifier refractory wall, and is partially reflected by the far end of the fiber. The time of flight of the light pulse in the fiber then gives an indication of the position of the fiber end, which is a function of the wall thickness when the fiber is embedded. Results obtained show a measurement accuracy of {+-}2cm in environment of 1000 C with a saw cut fiber end. When the fiber end is corroded by sodium carbide at 900 C, the accuracy is {+-}3cm. For the temperature measurement, a single crystal sapphire fiber sensor is designed. The sapphire fiber guides the broadband light from a light emitting diode to a sapphire wafer functioning as a Fabry-Perot interferometer and the wafer optical thickness is a function of temperature. The returned optical signal is then demodulated by multimode fiber based whitelight interferometry. The system was tested up to 1500 C with a measurement accuracy of {+-}10 C for the entire measurement range.

Anbo Wang; Kristie Cooper

2008-07-19

270

Wavefront sensing applications of binary optics  

Energy Technology Data Exchange (ETDEWEB)

The advent of micro- or binary optics technology has made possible the fabrication of a variety of new optical devices. Optical fabrication is no longer limited by surfaces that can be made by grinding and polishing, or even diamond turning. In fact, optics with no symmetry, no smooth surfaces, and that perform multiple functions can be readily fabricated. While these optics have a large number of applications, they are extremely useful for systems that require arrays of small optics or aperture multiplexing, since these are fabricated using computer controlled photo-lithography and etching processes. We have applied binary optics technology to construct various wavefront sensing using four mask processes to create 16 level optics. They are binary in the sense that they use discrete phase levels, not in the sense of using only two levels (they might more properly be called digital optics). We have found that 16 levels is adequate for most systems, giving greater than 99% of efficiency.

Neal, D.R.; Warren, M.E.; Gruetzner, J.K.

1994-02-01

271

Time domain optical spectrometry with fiber optic waveguides  

International Nuclear Information System (INIS)

[en] Spectrometers which use optical fibers to obtain time domain spectral dispersion are reviewed. Pulse transmission through fiber optic waveguides is discussed and the basic requirements for sources and detectors are given. Multiplex spectrometry and time-of-flight spectrometry are then discussed. Resolution, fiber requirements, instrumentation and specific spectrometers are presented

1983-01-01

272

Combinatorial Chemistry for Optical Sensing Applications  

Science.gov (United States)

The recent interest in combinatorial chemistry for the synthesis of selective recognition materials for optical sensing applications is presented. The preparation, screening, and applications of libraries of ligands and chemosensors against molecular species and metal ions are first considered. Included in this chapter are also the developments involving applications of combinatorial approaches to the discovery of sol-gel and acrylic-based imprinted materials for optical sensing of antibiotics and pesticides, as well as libraries of doped sol-gels for high-throughput optical sensing of oxygen. The potential of combinatorial chemistry applied to the discovery of new sensing materials is highlighted.

Díaz-García, M. E.; Luis, G. Pina; Rivero-Espejel, I. A.

273

Fiber optic intensity-modulated sensors: a review in biomechanics  

Science.gov (United States)

Fiber optic sensors have a set of properties that make them very attractive in biomechanics. However, they remain unknown to many who work in the field. Some possible causes are scarce information, few research groups using them in a routine basis, and even fewer companies offering turnkey and affordable solutions. Nevertheless, as optical fibers revolutionize the way of carrying data in telecommunications, a similar trend is detectable in the world of sensing. The present review aims to describe the most relevant contributions of fiber sensing in biomechanics since their introduction, from 1960s to the present, focusing on intensity-based configurations. An effort has been made to identify key researchers, research and development (R&D) groups and main applications.

Roriz, Paulo; Ramos, António; Santos, José L.; Simões, José A.

2012-12-01

274

Enhancing Optical Communications with Brand New Fibers  

DEFF Research Database (Denmark)

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.

Morioka, Toshio; Awaji, Yoshinari

2012-01-01

275

Research of surface plasma resonance optical fiber hydrogen sensor  

Science.gov (United States)

An optical fiber hydrogen sensor based on the measuring principle of surface plasma resonance is introduced. The structure of the hydrogen-sensitive head which is coated with Pd-Ag alloy film on the surface of the etched optical fiber is investigated theoretically. When hydrogen gas is absorbed into the Pd thin layer of the sensing head, the Pd hydride is formed and then the refraction index of the etched optical fiber surface will be changed with different hydrogen gas concentration. The surface plasma wave is stimulated by the light wave in optical fiber and the surface plasma resonance occurs between the thin metal layer and the medium surface of hydrogen gas. The Pd-Ag alloy film thickness versus the sensitivity of hydrogen sensing head is analyzed and optimized via the numerical method. The sensing head which is based on surface plasma resonance is manufactured and used in the experiment system of hydrogen gas detecting, and the experiment results demonstrate that the detecting system has high sensitivity with the hydrogen concentration in the range of 0%-4%, the accuracy, resolution and response time are respectively 5%, 0.1% and 30s. This sensor structure can be applied to detecting the low concentration of hydrogen gas.

Ou, Zhonghua; Guo, Xiaowei; Chen, Dejun; Dai, Zhiyong; Peng, Zengshou; Liu, Yongzhi

2008-12-01

276

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

277

Brillouin Corrosion Expansion Sensors for Steel Reinforced Concrete Structures Using a Fiber Optic Coil Winding Method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, a novel kind of method to monitor corrosion expansion of steel rebars in steel reinforced concrete structures named fiber optic coil winding method is proposed, discussed and tested. It is based on the fiber optical Brillouin sensing technique. Firstly, a strain calibration experiment...

Xuefeng Zhao; Peng Gong; Guofu Qiao; Jie Lu; Xingjun Lv; Jinping Ou

278

Adaptive control in optical fibers  

Energy Technology Data Exchange (ETDEWEB)

Adpative control in combination with ultrafast pulse shaping provides a compelling approach to defeat dispersion, distortion and harness nonlinear phenomena on the femtosecond timescale. Ultrafast pulses propagating in optical fibers generate a number of linear and nonlinear effects which affect the pulse during its travel. The main causes stem from the dependence of the index of refraction on frequency (given that short pulses have a large bandwidth) and from the so-called self-action effects which involve the dependence of the index of refraction on the pulse intensity (which is high given that the pulse energy is confined to a very short amount of time).

Omenetto, F. G. (Fiorenzo G.)

2002-01-01

279

Simulation of Three Different Double-Fiber Probes for Reflection Sensing  

Directory of Open Access Journals (Sweden)

Full Text Available In this study simulation results for three double-fiber optical designs for the reflection measurements are reported. Modeling is perused for three cases namely Equal Fibers (EF), transmitter fiber shorter (TS) and receiver fiber shorter (RS) designs. By proper modeling and written programs the operations of such symmetric double-fiber probes are simulated and the role of different crucial parameters such as fiber-to-fiber distance (t), fiber core radius (r) and fiber Numerical Aperture (NA) are investigated. In the second study simulation results for the transmitter fiber shorter and receiver fiber shorter designs are investigated for different fiber length differences (w). Finally simulation results for the three different designs of equal fibers, transmitter shorter and receiver fiber shorter probes are compared and optimum conditions are described. All three arrangements simulated here offer valuable results for sensing operations such as reflection or displacement measurements. However, the RS probe geometry offers a better design with the less dead region in comparison with the EF and TS designs.

R. Jafari; H. Golnabi

2010-01-01

280

Subsea fiber-optic communications  

Energy Technology Data Exchange (ETDEWEB)

High-cost and hazardous nature of recovering hydrocarbons offshore have led to the trend towards growth in subsea production control. The extended step-out distances of subsea completions is increasing the volume and complexity of subsea data communications beyond the capacity of conventional systems. Improved reservoir management using intelligent sensors, metering, and process equipment, requiring real-time monitoring and control, dictates the use of wideband communication. Fiber optics offers the necessary volume of data transmission, with the high-noise immunity needed for data integrity and safe operation, under the severe Electro-Magnetic Interference (EMI) environments created where high power motors and power cables are used subsea. The marinizing of optical, opto-electronic communication components for production control, data acquisition of subsea completions for the offshore oil industry are described.

High, G.; Wright, P.J. [Kvaerner FSSL Ltd., London (United Kingdom)

1997-05-01

 
 
 
 
281

All-Optical Polymer Fiber Devices.  

Science.gov (United States)

The goal of our research was to build an ultrafast all-optical switching device in a single mode polymer optical fiber. We have concentrated on both extensive processing and characterization studies. Activities included characterizing: refractive index pr...

M. G. Kuzyk

1998-01-01

282

Method for optical and mechanically coupling optical fibers  

Energy Technology Data Exchange (ETDEWEB)

A method and apparatus for splicing optical fibers. A fluorescing solder glass frit having a melting point lower than the melting point of first and second optical fibers is prepared. The solder glass frit is then attached to the end of the first optical fiber and/or the end of the second optical fiber. The ends of the optical fibers are aligned and placed in close proximity to each other. The solder glass frit is then heated to a temperature which is lower than the melting temperature of the first and second optical fibers, but which is high enough to melt the solder glass frit. A force is applied to the first and second optical fibers pushing the ends of the fibers towards each other. As the solder glass flit becomes molten, the layer of molten solder glass is compressed into a thin layer between the first and second optical fibers. The thin compressed layer of molten solder glass is allowed to cool such that the first and second optical fibers are bonded to each other by the hardened layer of solder glass.

Toeppen, John S. (Livermore, CA)

1996-01-01

283

Chirped fiber Bragg grating detonation velocity sensing.  

UK PubMed Central (United Kingdom)

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.

Rodriguez G; Sandberg RL; McCulloch Q; Jackson SI; Vincent SW; Udd E

2013-01-01

284

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

CERN Document Server

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...

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

2007-01-01

285

Laboratory Equipment Type Fiber Optic Refractometer  

Directory of Open Access Journals (Sweden)

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.

J. Turan; L. Ovsenik; M. Benca; E. F. Carome

2002-01-01

286

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

Science.gov (United States)

An all-optical 3D photoacoustic imaging probe that consists of an optical fiber probe for ultrasound detection and a bundle of hollow optical fibers for excitation of photoacoustic waves was developed. The fiber probe for ultrasound is based on a single-mode optical fiber with a thin polymer film attached to the output end surface that works as a Fabry Perot etalon. The input end of the hollow fiber bundle is aligned so that each fiber in the bundle is sequentially excited. A thin and flexible probe can be obtained because the probe system does not have a scanning mechanism at the distal end. PMID:24104094

Miida, Yusuke; Matsuura, Yuji

2013-09-23

287

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

UK PubMed Central (United Kingdom)

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

Miida Y; Matsuura Y

2013-09-01

288

Online fiber-optic spectrophotometry  

Energy Technology Data Exchange (ETDEWEB)

The Savannah River Plant operates two radio-chemical separations areas to recover uranium and plutonium from nuclear reactor fuel and target assemblies. Chemical processes in these areas are controlled based on laboratory analysis of samples extracted from the process. While analytical results from the laboratory are reliable, the process of pulling samples, transporting them to the laboratory, analyzing them, and then reporting results is time consuming and potentially exposes many workers to highly radioactive solutions. To improve the timeliness of chemical information and reduce personnel radiation exposure, the Savannah River Laboratory has developed an online fiber optic spectrophotometer which combines three new technologies, fiber optics, diode array spectrophotometers, and multivariate data analysis. The analyzer monitors the uranium and nitrate concentration of seven aqueous process streams in a uranium purification process. The analyzer remotely controls the sampling of each process stream and monitors the relative flow rate through each sampler. Spectrophotometric data from the analyzer is processed by multivariate data analysis to give both uranium and nitrate concentrations as well as an indication of the quality of the data.

Van Hare, D.R.; O' Rourke, P.E.; Prather, W.S.

1989-01-01

289

7 CFR 1755.903 - Fiber optic service entrance cables.  

Science.gov (United States)

...2010-01-01 2010-01-01 false Fiber optic service entrance cables. 1755...CONTRACT FORMS § 1755.903 Fiber optic service entrance cables. (a...section covers Agency requirements for fiber optic service entrance cables...

2010-01-01

290

New results in optical fiber Cherenkov calorimetry  

Energy Technology Data Exchange (ETDEWEB)

Quartz fiber calorimetry is a sampling calorimetry technique based on the detection of Cherenkov light generated in quartz optical fibers. Optical fibers transport only selected modes of light which results in very narrow visible showers. In addition, this technique is characterized by radiation resistance measured in gigarads and nanosecond pulse duration. The results of recent beam tests are presented, illustrating behavior of electromagnetic calorimeters based on this technique as a function of their absorber type, density and distribution of fibers and fiber types. (orig.).

Contin, A. [Bologna Univ. (Italy); De Salvo, R. [Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Gorodetzky, P. [CRN and Universite Louis Pasteur, Strasbourg (France); Helleboid, J.M. [CRN and Universite Louis Pasteur, Strasbourg (France); Johnson, K.F. [Florida State Univ., Tallahassee, FL (United States); Juillot, P. [CRN and Universite Louis Pasteur, Strasbourg (France); Lazic, D. [Florida State Univ., Tallahassee, FL (United States); Lundin, M. [CRN and Universite Louis Pasteur, Strasbourg (France)

1995-12-11

291

Bulkhead Interface Chassis for optical fiber patching  

Energy Technology Data Exchange (ETDEWEB)

An optical fiber patch panel was designed to meet the changing needs of optical fiber communication link installations. This paper deals with the specification and construction details of the Bulkhead Interface Chassis patch panel. Included is ordering information for the commercial parts needed and shop drawings of the pieces to be machined.

George, M.

1985-06-01

292

Fiber optic applications for laser polarized targets  

Energy Technology Data Exchange (ETDEWEB)

For the past two years, the laser polarized target group at Argonne has been used multi-mode fiber optic patch cords for a variety of applications. In this paper, the authors describe the design for transporting high power laser beams with optical fibers currently in use at IUCF.

Cummings, W.J.; Kowalczyk, R.S. [Argonne National Lab., IL (United States). Physics Div.

1997-10-01

293

ITO based fiber optic SPR sensor  

Science.gov (United States)

A surface plasmon resonance (SPR) based fiber optic sensor with ITO layer coated on the core of the optical fiber is presented and theoretically analyzed. It has been shown that the sensitivity of the ITO layer based SPR sensor increases with the increase of ITO layer thickness. Moreover, 290 nm thick ITO layer based SPR sensor possesses high sensitivity of 2485 nm/ RIU.

Rani, Mahima; Sharma, Navneet K.

2013-06-01

294

Biomedical fiber optic instrumentation: Volume 2131  

Energy Technology Data Exchange (ETDEWEB)

This conference was held January 24--27, 1994 in Los Angeles, California. The purpose of the conference was to provide a forum for state-of-the-art information on the use of fiber optics in biomedical instruments. Attention is focused on the following: specialty fibers for biomedical and systems applications; medical lasers and systems III; and optical sensors in medical diagnostics.

Harrington, J.A.; Harris, D.M.; Katzir, A.; Milanovich, F.P. (eds.)

1994-01-01

295

Fiber-optic liquid level sensor  

Energy Technology Data Exchange (ETDEWEB)

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.

Weiss, Jonathan D. (Albuquerque, NM)

1991-01-01

296

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

1978-01-01

297

Multiaxis electric field sensing using slab coupled optical sensors.  

UK PubMed Central (United Kingdom)

This paper provides the details of a multiaxis electric field sensor. The sensing element consists of three slab coupled optical-fiber sensors that are combined to allow directional electric field sensing. The packaged three-axis sensor has a small cross-sectional area of 0.5 cm×0.5 cm by using an x-cut crystal. A method is described that uses a sensitivity-matrix approach to map the measurements to field components. The calibration and testing are described, resulting in an average error of 1.5°.

Perry D; Chadderdon S; Forber R; Wang WC; Selfridge R; Schultz S

2013-03-01

298

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.).

1987-01-01

299

Fiber optic applications in nuclear power plants  

International Nuclear Information System (INIS)

[en] Fiber optic technology possesses many desirable attributes for applications in commercial nuclear power plants. The non-electrical nature of fiber optics is an important factor in an industry governed by federal safety regulations such as Class 1E isolation and separation criteria. Immunity from Electromagnetic Interference (EMI), an increasing industry problem area, is another significant characteristic. Because of the extremely wide bandwidth offered, fiber optics better addresses the data acquisition and communication requirements of the complex processes of a nuclear power plant. Potential for fiber optic sensor applications exists within the nuclear industry because their small size and physical flexibility allows access into normally inaccessible areas. They possess high accuracy and allow environmentally sensitive electronics to be remotely located. The purpose of this paper is to explore current applications for fiber optic technology in modern nuclear plants, document examples of present day usage in C-E plants and suggest possible future application areas

1984-12-10

300

Fiber optic applications in nuclear power plants  

International Nuclear Information System (INIS)

[en] Fiber optic technology possesses many desirable attributes for applications in commercial nuclear power plants. The non-electrical nature of fiber optics is an important factor in an industry governed by federal safety regulations such as Class 1E isolation and separation criteria. Immunity from Electromagnetic Interference (EMI), an increasing industry problem area, is another significant characteristic. Because of the extremely wide bandwidth offered, fiber optics better addresses the data acquistion and communication requirements of the complex processes of a nuclear power plant. Potential for fiber optic sensor applications exists within the nuclear industry because their small size and physical flexibility allows access into normally inaccessible areas. They possess high accuracy and allow environmentally sensitive electronics to be remotely located. The purpose of this paper is to explore current applications for fiber optic technology in modern nuclear plants, document examples of present day usage in C-E plants and suggest possible future application areas

1984-01-01

 
 
 
 
301

Optical amplification for the fiber interferometer gyro  

International Nuclear Information System (INIS)

[en] An improvement for a fiber interferometer gyro provides for greater rotation rate sensitivity. The gyro has a single mode fiber coiled about an identical area a great number of times. A single external laser sends pulses of energy which are split and passed in opposite directions through the coiled fiber and a pair of optical amplifiers inserted to amplify the energy pulses. This permits the length of the coiled fiber to be increased and, hence , provides for greater interferometer sensitivity

1981-01-01

302

A Polymer Optical Fiber Fuel Level Sensor: Application to Paramotoring and Powered Paragliding  

Directory of Open Access Journals (Sweden)

Full Text Available A low-cost intensity-based polymer optical fiber (POF) sensor for fuel level measurements in paramotoring and powered paragliding is presented, exploiting the advantages of the optical fiber sensing technology. Experimental results demonstrate that the best option can be performed by stripping the fiber at the desired discrete points to measure the fuel level as well as with a gauge-shape fiber bending. The prototype has a good linearity, better than 4% full scale (F.S.), and sensitivity around 0.5 V per bend are obtained. Hysteresis due to residual fluid at the sensing points is found to be less than 9% F.S.

David Sánchez Montero; Pedro Contreras Lallana; Carmen Vázquez

2012-01-01

303

Spontaneous inelastic Rayleigh scattering in optical fibers.  

UK PubMed Central (United Kingdom)

Rayleigh scattering (RS) adds noise to signals that are transmitted over optical fibers and other optical waveguides. This noise can be the dominant noise source in a range between 10 Hz and 100 kHz from the carrier and can seriously degrade the performance of optical systems that require low close-in noise. Using heterodyne techniques, we demonstrate that the backscattered close-in noise spectrum in optical fibers is symmetric about the carrier and grows linearly with both input power and fiber length. These results indicate that the RS is spontaneous and is due to finite-lifetime thermal fluctuations in the glass.

Okusaga O; Cahill JP; Docherty A; Menyuk CR; Zhou W

2013-02-01

304

Low-cost fiber-optic chemochromic hydrogen detector  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1998-08-01

305

Characteristics of optical fibers to radiation  

Energy Technology Data Exchange (ETDEWEB)

Recently, various reports have been issued on the radiation resistivity of optical fibers. Many of them treated the examination on the increase of transmission loss and the recovery characteristics after stopping irradiation when ..gamma..- or X-ray, neutron or electron beam was irradiated to optical fibers. Lately, however, the theoretical studies which were focused to the optical bleaching effect and the change of glass structure were also presented. In this report, the radiation characteristics of the optical fibers employed for communication and control cables and the various phenomena which have been the problems in image guides and light guides are described. The optical fibers used for the experiment were the graded index fibers of Ge- and P-doped core, and the SI type fibers of OH-doped silica glass core and highly pure silica glass core. The increase of transmission loss was measured on these fibers of 15 to 100 m length. For communication and control optical fibers, the loss was determined by the amount of dose, and did not depend on dose rate in GI type, but the loss depended on both dose and dose rate in SI type. For the optical fibers employed for image and light guides, in addition to the increase of loss by irradiation, it is generally said that the generation of fluorescence from optical fibers should also be carefully investigated. When X-ray was irradiated to the fibers of silica glass core, the generation of fluorescence increased with the increase of dose. This suggests that the problems such as the increase of background due to fluorescence may occur when light guides and the like are used in radiation fields.

Iino, Akira; Yano, Shin-ichi; Nishimura, Masao

1983-03-01

306

Controllable Optical Solitons in Optical Fiber System with Distributed Coefficients  

International Nuclear Information System (INIS)

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

2011-04-15

307

Fiber optic D dimer biosensor  

Energy Technology Data Exchange (ETDEWEB)

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. 4 figs.

Glass, R.S.; Grant, S.A.

1999-08-17

308

Rugged fiber optic probe for raman measurement  

Energy Technology Data Exchange (ETDEWEB)

An optical probe for conducting light scattering analysis is disclosed. The probe comprises a hollow housing and a probe tip. A fiber assembly made up of a transmitting fiber and a receiving bundle is inserted in the tip. A filter assembly is inserted in the housing and connected to the fiber assembly. A signal line from the light source and to the spectrometer also is connected to the filter assembly and communicates with the fiber assembly. By using a spring-loaded assembly to hold the fiber connectors together with the in-line filters, complex and sensitive alignment procedures are avoided. The close proximity of the filter assembly to the probe tip eliminates or minimizes self-scattering generated by the optical fiber. Also, because the probe can contact the sample directly, sensitive optics can be eliminated.

O' Rourke, Patrick E. (Martinez, GA); Toole, Jr., William R. (Aiken, SC); Nave, Stanley E. (Evans, GA)

1998-01-01

309

Mode conversion in hybrid optical fiber coupler  

Science.gov (United States)

Designing of all in-line fiber optic systems with a supercontinuum light source gives some issues. The use of a standard single mode fiber (SMF) as an input do not secure single mode transmission in full wavelength range. In the paper, the experimental results of the tested hybrid fiber optic coupler were presented. It was manufactured by fusing a standard single mode fiber (SMF28) and a photonic crystal fiber (PCF). The fabrication process is based on the standard fused biconical taper technique. Two types of large mode area fibers (LMA8 and LAM10 NKT Photonics) with different air holes arrangements were used as the photonic crystal fiber. Spectral characteristics within the range of 800 nm - 1700 nm were presented. All process was optimized to obtain a mode conversion between SMF and PCF and to reach a single mode transmission in the PCF output of the coupler.

Stasiewicz, Karol A.; Marc, P.; Jaroszewicz, Leszek R.

2012-05-01

310

Evanescent-wave infrared spectroscopy with flattened fibers as sensing elements.  

Science.gov (United States)

Fiber-optic evanescent-wave spectroscopy (FEWS) is a novel method for measuring the absorption spectra of samples in contact with a segment of an optical fiber that serves as a sensing element. We used a cylindrical IR-transmitting AgClBr fiber whose central section, of length L, was flattened to a thickness d. This section was used as the FEWS sensing element. Our theoretical work predicted that the signals obtained in FEWS measurements should be linearly dependent on L and inversely proportional to d. Decreasing the thickness can significantly increase its sensitivity of the sensor. These theoretical results were verified experimentally by measurements of methanol and water. PMID:14680161

Raichlin, Y; Fel, L; Katzir, A

2003-12-01

311

Thermal Strain Analysis of Optic Fiber Sensors  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Shiuh-Chuan Her; Chih-Ying Huang

2013-01-01

312

Microbend fiber-optic temperature sensor  

Energy Technology Data Exchange (ETDEWEB)

A temperature sensor is made of optical fiber into which quasi-sinusoidal microbends have been permanently introduced. In particular, the present invention includes a graded-index optical fiber directing steady light through a section of the optical fiber containing a plurality of permanent microbends. The microbend section of the optical fiber is contained in a thermally expansive sheath, attached to a thermally expansive structure, or attached to a bimetallic element undergoing temperature changes and being monitored. The microbend section is secured to the thermally expansive sheath which allows the amplitude of the microbends to decrease with temperature. The resultant increase in the optical fiber's transmission thus allows temperature to be measured. The plural microbend section of the optical fiber is secured to the thermally expansive structure only at its ends and the microbends themselves are completely unconstrained laterally by any bonding agent to obtain maximum longitudinal temperature sensitivity. Although the permanent microbends reduce the transmission capabilities of fiber optics, the present invention utilizes this phenomenon as a transduction mechanism which is optimized to measure temperature.

Weiss, Jonathan D. (Albuquerque, NM)

1995-01-01

313

Thermal strain analysis of optic fiber sensors.  

UK PubMed Central (United Kingdom)

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.

Her SC; Huang CY

2013-01-01

314

Multiwavelength optical fiber refractive index profiling  

Science.gov (United States)

Fourier transform spectroscopy and interference microscopy are combined to provide the world's first multi-wavelength optical fiber refractive index profile (RIP) measurements. The RIP and its spectral dependence are obtained with submicron spatial resolution across an octave stretching from about 500 nm to the 1 micron operating band of Yb-doped fiber lasers and amplifiers. In contrast to commercial Refracted Near Field (RNF) technology, which measures at a cleave, the technique described here measures transversely through the side of an uncleaved fiber, enabling measurements of axial fiber RIP variations found in fiber gratings, physical tapers, and fusion splices.

Yablon, Andrew D.

2010-02-01

315

Stable transmission of radio frequency signals on fiber links using interferomectric delay sensing  

Energy Technology Data Exchange (ETDEWEB)

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.

Wilcox, Russell B.; Byrd, J.M.; Doolittle, Lawrence; Huang, Gang; Staples, J.W.

2009-07-29

316

Tilted fiber Bragg grating in graded-index multimode fiber and its sensing characteristics  

Science.gov (United States)

Tilted fiber Bragg grating (TFBG) and reflective tilted fiber Bragg grating (R-TFBG) were proposed and demonstrated in the graded-index multimode fiber (GI-MMF). The TFBGs with grating planes tilted at an angle of 2.5° corresponding to the fiber axis were inscribed. The TFBGs in the GI-MMF had the good linear sensitivity to the temperature, strain and curvature. The fiber was then cleaved at the far end of the TFBG to form an R-TFBG using the Fresnel reflection of the fiber end. The reflective spectra of the R-TFBG were given, and the temperature sensing properties were also investigated.

Li, Dengyong; Gong, Yuan; Wu, Yu

2013-06-01

317

Optical humidity sensing behaviour of sol–gel processed nanostructured ZnO films  

Directory of Open Access Journals (Sweden)

Full Text Available This paper reports the humidity sensing behaviour of sol–gel processed ZnO films deposited on U-shaped borosilicate rods as substitute of optical fiber having the same radius of curvature. The films prepared on each sensing element were dried for 15 minutes using a 100 watt electric bulb. Both ends of the U-shaped borosilicate rod were coupled to optical fibers. Light from a He-Ne laser is fed into the sensing element through one of the ends. Light is received from the other end of fiber coupled into an optical power meter. Variations in the intensity of light with changes in humidity from 10% to 95% have been recorded. Characterization of sensing material has been done using SEM.

B.C. Yadav; R.C. Yadav; G.C. Dubey

2009-01-01

318

Stimulated thermal Rayleigh scattering in optical fibers.  

UK PubMed Central (United Kingdom)

Recently, mode instability was observed in optical fiber lasers at high powers, severely limiting power scaling for single-mode outputs. Some progress has been made towards understanding the underlying physics. A thorough understanding of the effect is critical for continued progress of this very important technology area. Mode instability in optical fibers is, in fact, a manifestation of stimulated thermal Rayleigh scattering. In this work, a quasi-closed-form solution for the nonlinear coupling coefficient is found for stimulated thermal Rayleigh scattering in optical fibers. The results help to significantly improve understanding of mode instability.

Dong L

2013-02-01

319

The Soliton Transmissions in Optical Fibers  

Directory of Open Access Journals (Sweden)

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.

Leos Bohac

2010-01-01

320

Fiber optic communication in borehole applications  

Energy Technology Data Exchange (ETDEWEB)

The Telemetry Technology Development Department have, in support of the Advanced Geophysical Technology Department and the Oil Recovery Technology Partnership, developed a fiber optic communication capability for use in borehole applications. This environment requires the use of packaging and component technologies to operate at high temperature (up to 175{degrees}C) and survive rugged handling. Fiber optic wireline technology has been developed by The Rochester Corporation under contract to Sandia National Labs and produced a very rugged, versatile wireline cable. This development has utilized commercial fiber optic component technologies and demonstrated their utility in extreme operating environments.

Franco, R.J.; Morgan, J.R.

1997-04-01

 
 
 
 
321

Microbend fiber-optic chemical sensor  

Energy Technology Data Exchange (ETDEWEB)

A microbend fiber-optic chemical sensor for detecting chemicals in a sample, and a method for its use, is disclosed. The sensor comprises at least one optical fiber having a microbend section (a section of small undulations in its axis), for transmitting and receiving light. In transmission, light guided through the microbend section scatters out of the fiber core and interacts, either directly or indirectly, with the chemical in the sample, inducing fluorescence radiation. Fluorescence radiation is scattered back into the microbend section and returned to an optical detector for determining characteristics of the fluorescence radiation quantifying the presence of a specific chemical.

Weiss, Jonathan D. (Albuquerque, NM)

2002-01-01

322

Manufacture of optical fibers for communications  

Energy Technology Data Exchange (ETDEWEB)

Optical fibers are hair thin strands of silica based glass or plastic or a combination of both used to transmit optical signals. In the field of communications silica based glass fibers are used almost exclusively. Optical fibers are widely used in the field of telecommunications and CATV. In addition, they are also widely used in medical applications, industrial control applications, a variety of sensor applications, and military applications. Currently, tens of millions of km of fibers are deployed in worldwide information movement networks of all types. The total fiber optic cable market in 1993 was close to $4.0 Billion, and is projected to grow approximately 15% annually till 1998. The fiber manufacturing industry has thus matured very rapidly within the last decade, and tremendous advances have been made in terms of quality and productivity. I will briefly describe the basic requirements for a fiber and then discuss fiber manufacturing. I will conclude with my view of the areas of future attention in fiber manufacturing.

Tariyal, B.K. [LITESPEC Inc., Research Triangle Park, NC (United States)

1995-12-01

323

Tamper indicating and sensing optical-based smart structures  

International Nuclear Information System (INIS)

[en] This paper has presented an overview of the type of optical-based structures that can be designed and constructed. These smart structures are capable of responding to their environment. The examples given represent a modest sampling of the complexity that can be achieved in both design and practice. Tamper-indicating containers and smart, sensing windows demonstrate just a few of the applications. We have shown that optical-based smart structures can be made multifunctional with the sensing built in. The next generation smart structure will combine the sensing functionality of these optical-based smart structures with other sensors such as piezoelectrics and electro-rheological fluids to not only be able to respond to the environment, but to adapt to it as well. An example of functionality in this regime would be a piezosensor that senses pressure changes (e.g., shock waves), which then causes an electro-rheological fluid to change viscosity. A fiber sensor located in or near the electro-rheological fluid senses the stiffness change and sends a signal through a feedback loop back to the piezosensor for additional adjustments to the electro-rheological fluid

1995-01-01

324

Tamper indicating and sensing optical-based smart structures  

Energy Technology Data Exchange (ETDEWEB)

This paper has presented an overview of the type of optical-based structures that can be designed and constructed. These smart structures are capable of responding to their environment. The examples given represent a modest sampling of the complexity that can be achieved in both design and practice. Tamper-indicating containers and smart, sensing windows demonstrate just a few of the applications. We have shown that optical-based smart structures can be made multifunctional with the sensing built in. The next generation smart structure will combine the sensing functionality of these optical-based smart structures with other sensors such as piezoelectrics and electro-rheological fluids to not only be able to respond to the environment, but to adapt to it as well. An example of functionality in this regime would be a piezosensor that senses pressure changes (e.g., shock waves), which then causes an electro-rheological fluid to change viscosity. A fiber sensor located in or near the electro-rheological fluid senses the stiffness change and sends a signal through a feedback loop back to the piezosensor for additional adjustments to the electro-rheological fluid.

Sliva, P.; Anheier, N.C.; Gordon, N.R.; Simmons, K.L.; Stahl, K.A.; Undem, H.A.

1995-05-01

325

Optical design of a high power fiber optic coupler  

Energy Technology Data Exchange (ETDEWEB)

Fiber optic beam delivery systems are replacing conventional mirror delivery systems for many reasons (e.g., system flexibility and redundancy, stability, and ease of alignment). Commercial products are available that use of fiber optic delivery for laser surgery and materials processing. Also, pump light of dye lasers can be delivered by optical fibers. Many laser wavelengths have been transported via optical fibers; high power delivery has been reported for argon, Nd:YAG, and excimer. We have been developing fiber optic beam delivery systems for copper vapor laser light; many of the fundamental properties of these systems are applicable to other high power delivery applications. A key element of fiber optic beam delivery systems is the coupling of laser light into the optical fiber. For our application this optical coupler must be robust to a range of operating parameters and laser characteristics. We have access to a high power copper vapor laser beam that is generated by a master oscillator/power amplifier (MOPA) chain comprised of three amplifiers. The light has a pulse width of 40--50 nsec with a repetition rate of about 4 kHz. The average power (nominal) to be injected into a fiber is 200 W. (We will refer to average power in this paper.) In practice, the laser beam's direction and collimation change with time. These characteristics plus other mechanical and operational constraints make it difficult for our coupler to be opto-mechanically referenced to the laser beam. We describe specifications, design, and operation of an optical system that couples a high-power copper vapor laser beam into a large core, multimode fiber. The approach used and observations reported are applicable to fiber optic delivery applications. 6 refs., 6 figs.

English, R.E. Jr.; Halpin, J.M.; House, F.A.; Paris, R.D.

1991-06-19

326

Optical design of a high power fiber optic coupler  

International Nuclear Information System (INIS)

Fiber optic beam delivery systems are replacing conventional mirror delivery systems for many reasons (e.g., system flexibility and redundancy, stability, and ease of alignment). Commercial products are available that use of fiber optic delivery for laser surgery and materials processing. Also, pump light of dye lasers can be delivered by optical fibers. Many laser wavelengths have been transported via optical fibers; high power delivery has been reported for argon, Nd:YAG, and excimer. We have been developing fiber optic beam delivery systems for copper vapor laser light; many of the fundamental properties of these systems are applicable to other high power delivery applications. A key element of fiber optic beam delivery systems is the coupling of laser light into the optical fiber. For our application this optical coupler must be robust to a range of operating parameters and laser characteristics. We have access to a high power copper vapor laser beam that is generated by a master oscillator/power amplifier (MOPA) chain comprised of three amplifiers. The light has a pulse width of 40--50 nsec with a repetition rate of about 4 kHz. The average power (nominal) to be injected into a fiber is 200 W. (We will refer to average power in this paper.) In practice, the laser beam's direction and collimation change with time. These characteristics plus other mechanical and operational constraints make it difficult for our coupler to be opto-mechanically referenced to the laser beam. We describe specifications, design, and operation of an optical system that couples a high-power copper vapor laser beam into a large core, multimode fiber. The approach used and observations reported are applicable to fiber optic delivery applications. 6 refs., 6 figs

1991-01-01

327

Templated Chemically Deposited Semiconductor Optical Fiber Materials  

Science.gov (United States)

Chemical deposition is a powerful technology for fabrication of planar microelectronics. Optical fibers are the dominant platform for telecommunications, and devices such as fiber lasers are forming the basis for new industries. High-pressure chemical vapor deposition (HPCVD) allows for conformal layers and void-free wires of precisely doped crystalline unary and compound semiconductors inside the micro-to-nanoscale-diameter pores of microstructured optical fibers (MOFs). Drawing the fibers to serve as templates into which these semiconductor structures can be fabricated allows for geometric design flexibility that is difficult to achieve with planar fabrication. Seamless coupling of semiconductor optoelectronic and photonic devices with existing fiber infrastructure thus becomes possible, facilitating all-fiber technological approaches. The deposition techniques also allow for a wider range of semiconductor materials compositions to be exploited than is possible by means of preform drawing. Gigahertz bandwidth junction-based fiber devices can be fabricated from doped crystalline semiconductors, for example. Deposition of amorphous hydrogenated silicon, which cannot be drawn, allows for the exploitation of strong nonlinear optical function in fibers. Finally, crystalline compound semiconductor fiber cores hold promise for high-power infrared light-guiding fiber devices and subwavelength-resolution, large-area infrared imaging.

Sparks, Justin R.; Sazio, Pier J. A.; Gopalan, Venkatraman; Badding, John V.

2013-07-01

328

Optical trapping of a microscopic object using optical fiber; Hikari fiber wo mochiita bisho buttai no hikari hosoku  

Energy Technology Data Exchange (ETDEWEB)

In this paper, an optical trapping method using optical fiber (Optical Fiber Trapping Method) is proposed. This optical fiber trapping method has many following merits, if the microscopic objects are optically trapped near the fiber end. (1) Optical trapping systems using optical fiber are simple and inexpensive. (2) Optical sources can be changed easily using optical connectors. (3) Trapping point is easily noticeable, because a fiber end points out the focal point. Experimental results are as follows. (1) Optical trapping of a micro-object is easily achieved using an optical fiber whose end is polished to a tapered spherical end. (2) Optically trapped object can be freely transferred in 2-D plain, synchronized to the trapping fiber. (3) Optical manipulation characteristics for, the optically trapped object depend on the distance between the trapping fiber end and the micro-object. 11 refs., 8 figs.

Taguchi, K.; Ueno, H.; Ikeda, M. [Fukuyama University, Hiroshima (Japan)

1998-10-01

329

An In-Reflection Strain Sensing Head Based on a Hi-Bi Photonic Crystal Fiber  

Directory of Open Access Journals (Sweden)

Full Text Available A photonic crystal fiber-based sensing head is proposed for strain measurements. The sensor comprises a Hi-Bi PCF sensing head to measure interferometric signals in-reflection. An experimental background study of the sensing head is conducted through an optical backscatter reflectometer confirming the theoretical predictions, also included. A cost effective setup is proposed where a laser is used as illumination source, which allows accurate high precision strain measurements. Thus, a sensitivity of ~7.96 dB/me was achieved in a linear region of 1,200 ?e.

Sergio Rota-Rodrigo; Ana M. R. Pinto; Mikel Bravo; Manuel Lopez-Amo

2013-01-01

330

Robust optical fiber bending sensor to measure frequency of vibration  

Science.gov (United States)

A simple technique for sensing the acoustic vibration of a cantilever beam, using a single-fiber Mach–Zehnder interferometer, is presented. The interferometer consists of two concatenated low-loss fused fiber tapers, with a waist diameter of 60 ?m, separated by an un-tapered fiber section of 10 mm length. The interferometer transmitted signal is modulated when the device is bent under the presence of an external acoustic signal. The optical fiber device glued directly on a metallic cantilever beam is capable of measuring frequency of the resonant modes. The interrogation set-up is simple consisting of a single tunable diode laser and a photodetector. The measured frequencies of the resonating modes agree with the numerical results obtained by the Finite Element Method.

Hernández-Serrano, Arturo Ignacio; Salceda-Delgado, Guillermo; Moreno-Hernández, David; Martínez-Ríos, Alejandro; Monzón-Hernández, David

2013-09-01

331

Side-emitting fiber optic position sensor  

Energy Technology Data Exchange (ETDEWEB)

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.

Weiss, Jonathan D. (Albuquerque, NM)

2008-02-12

332

Unique components for photonics diagnostic systems using fiber optics  

Energy Technology Data Exchange (ETDEWEB)

The main optical components discussed that must be custom made are: foreoptics for electronic streak cameras, spectral multiplexing of two-dimensional images, instruments to compensate for material dispersion in optical fibers, in-line filter, fiber optic switch, in-line attenuator, fiber translator, and coherent fiber optics. Design and performance characteristics of these components are discussed.

Reedy, R.P.

1986-02-06

333

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

Directory of Open Access Journals (Sweden)

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.

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

2010-01-01

334

A microstructured Polymer Optical Fiber Biosensor  

DEFF Research Database (Denmark)

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.

Emiliyanov, Grigoriy Andreev; Jensen, Jesper Bo

2006-01-01

335

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.

1988-01-01

336

Fiber Optic Communications Technology. A Status Report.  

Science.gov (United States)

|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…

Hull, Joseph A.

337

Fiber optics applications in hostile environments  

Energy Technology Data Exchange (ETDEWEB)

This Conference focuses on applications of optical fibers in hostile environments. As the introductory paper in this Conference, this communication will trace the evolution of applications of fibers in hostile environments and explore some of the motivations for these applications. A few key examples will be used.

Lyons, P.B.

1986-01-01

338

Fiber Optic Neutron Imaging System: Calibration.  

Science.gov (United States)

Two neutron imaging experiments using fiber optics have been performed at the Nevada Test Site. In each experiment, an array of scintillator fluor tubes is exposed to neutrons. Light is coupled out through radiation resistant PCS fibers (8-m long) into hi...

R. M. Malone C. E. Gow D. R. Thayer

1981-01-01

339

Fiber optics welder having movable aligning mirror  

Energy Technology Data Exchange (ETDEWEB)

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.

Higgins, Robert W. (Los Alamos, NM); Robichaud, Roger E. (Jemez Springs, NM)

1981-01-01

340

A reliable, sensitive and fast optical fiber hydrogen sensor based on surface plasmon resonance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report for the first time on the experimental response of a Surface Plasmon Resonance fiber optic sensor based on wavelength modulation for hydrogen sensing. This approach of measuring the hydrogen concentration makes the sensor insensitive to intensity fluctuations. The intrinsic fiber sensor de...

Perrotton, C.; Westerwaal, R.J.; Javahiraly, N.; Slaman, M.; Schreuders, H.; Dam, B.; Meyrueis, P.

 
 
 
 
341

Measurement of Faraday rotation in twisted optical fiber using rotating polarization and analog phase detection  

Energy Technology Data Exchange (ETDEWEB)

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.

Chandler, G.I.; Forman, P.R.; Jahoda, F.C.

1985-01-01

342

Fiber-Optic Vibration Sensor Based on Multimode Fiber  

Directory of Open Access Journals (Sweden)

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.

I. Lujo; P. Klokoc; T. Komljenovic; M. Bosiljevac; Z. Sipus

2008-01-01

343

Optical fiber sensor technique for strain measurement  

Energy Technology Data Exchange (ETDEWEB)

Laser light from a common source is split and conveyed through two similar optical fibers and emitted at their respective ends to form an interference pattern, one of the optical fibers having a portion thereof subjected to a strain. Changes in the strain cause changes in the optical path length of the strain fiber, and generate corresponding changes in the interference pattern. The interference pattern is received and transduced into signals representative of fringe shifts corresponding to changes in the strain experienced by the strained one of the optical fibers. These signals are then processed to evaluate strain as a function of time, typical examples of the application of the apparatus including electrodeposition of a metallic film on a conductive surface provided on the outside of the optical fiber being strained, so that strains generated in the optical fiber during the course of the electrodeposition are measurable as a function of time. In one aspect of the invention, signals relating to the fringe shift are stored for subsequent processing and analysis, whereas in another aspect of the invention the signals are processed for real-time display of the strain changes under study.

Butler, Michael A. (Albuquerque, NM); Ginley, David S. (Albuquerque, NM)

1989-01-01

344

OPTICAL FIBER SHEET AND BODY MOTION SENSOR  

UK PubMed Central (United Kingdom)

A body motion sensor, such as an SAS diagnostic device, with which a subject can be examined in a state close to that in an ordinary living environment and it is possible to clearly discriminate between an apnea state and a hypopnea state by means of a relatively simple analytical method and an optical fiber sheet suitable for use in the sensor. The body motion sensor, such as an SAS diagnostic device, comprises a light source (2) such as an LED, an optical fiber sheet (10), and an analysis unit (3) that determines fluctuations in the quantity of light outputted from the optical fiber sheet (10) and detects motions of the body. As the optical fiber sheet (10), use is made of an optical fiber sheet (10) comprising a planar object (20), such as a fabric, paper, or plastic sheet, and graded-index optical quartz fibers (11) directly or indirectly disposed thereon or affixed thereto When the sheet (10) is produced, it is preferred to use a pressure-sensitive adhesive sheet (30) comprising a sheet support (31), such as paper or fabric, and a pressure-sensitive adhesive layer (32) formed thereon.

HOSOYA TOSHIFUMI; KUWA KAZUHIRO; MITACHI SEIKO

345

Feasibility of optical sensing for robotics in highly radioactive environments  

International Nuclear Information System (INIS)

The application of robotics for repair, refurbishing or dismantling of nuclear installations implies eventually severe radiation resistance requirements on embarked components and subsystems. This is particularly critical when optical sensing is considered. Optoelectronic components and optical fibers are indeed quite sensitive to radiation, and without special design are rapidly out-of-operation in such an environment. This paper reports the results of a series of ? irradiation experiments on such devices, and identify their behavior under radiation. Test results show that carefully selected optical fibers can keep their radiation induced attenuation lower than 0.3 dB/m even up to a total dose of 10 MGy. Temperature annealing can even lower this attenuation down to 0.1 dB/m. On the other hand, commercially available light emitting diodes and photodiodes present attenuations figures up to 15 dB, even after a gamma irradiation as low as 250 kGy. However, properly chosen bias procedures are shown to greatly enhance this figure. The paper concludes by showing the feasibility of optical sensing for proximity measurement and data transmission for nuclear robots used under severe radiation conditions.

1993-01-01

346

Total light loss optic spectroscopy. Progress towards a fiber optic Raman organic vapor sensor  

Energy Technology Data Exchange (ETDEWEB)

A Raman probe has been developed utilizing a single optical fiber as both a light pipe and an active sensing element. By coating a small segment of the surface of an exposed glass fiber core with a thin polymer film, an inverted waveguide is formed where light transmitted down the fiber is stripped out of the core and into the polymer film. The polymer coating is used both as a waveguide and as a medium for concentrating small organic molecules to be interrogated by Raman spectroscopy. The ability of the fiber optic thin film waveguide probe to detect organic vapors is demonstrated. The utility of the probe in the detection of nonaqueous phase liquids (NAPLs) is also described.

Kyle, K.R.; Vess, T.M.; Angel, S.M.

1993-09-01

347

Benefits of glass fibers in solar fiber optic lighting systems.  

UK PubMed Central (United Kingdom)

The transmission properties and coupling of solar light have been studied for glass core multimode fibers in order to verify their benefits for a solar fiber optic lighting system. The light transportation distance can be extended from 20 m with plastic fibers to over 100 m with the kind of glass fibers studied here. A high luminous flux, full visible spectrum, as well as an outstanding color rendering index (98) and correlated color temperature similar to the direct sun light outside have been obtained. Thus the outstanding quality of solar light transmitted through these fibers would improve the visibility of all kinds of objects compared to fluorescent and other artificial lighting. Annual relative lighting energy savings of 36% in Uppsala, Sweden, and 76% in Dubai were estimated in an office environment. The absolute savings can be doubled by using glass optical fibers, and are estimated to be in the order of 550??kWh/year in Sweden and 1160??kWh/year in Dubai for one system of only 0.159??m2 total light collecting area. The savings are dependent on the fiber length, the daily usage time of the interior, the type of artificial lighting substituted, the system light output flux, and the available time of sunny weather at the geographic location.

Volotinen TT; Lingfors DH

2013-09-01

348

Tunable Polymer Fiber Bragg Grating (FBG) Inscription: Fabrication of Dual-FBG Temperature Compensated Polymer Optical Fiber Strain Sensors  

DEFF Research Database (Denmark)

We demonstrate stable wavelength tunable inscription of polymer optical fiber Bragg gratings (FBGs). By straining the fiber during FBG inscription, we linearly tune the center wavelength over 7 nm with less than 1% strain. Above 1% strain, the tuning curve saturates and we show a maximum tuning of 12 nm with 2.25% strain. We use this inscription method to fabricate a dual-FBG strain sensor in a poly (methyl methacrylate) single-mode microstructured polymer optical fiber and demonstrate temperature compensated strain sensing around 850 nm.

Yuan, Scott Wu; Stefani, Alessio

2012-01-01

349

Theoretical investigation of absorption and sensitivity of nano-plasmonic fiber optic sensors  

Science.gov (United States)

In this paper, fiber-optic sensor based on surface plasmon resonance (SPR) is considered. The fiber-optic sensor is coated with thin nanoparticle metallic films. The nanoparticle metallic film consists of spherical metallic nanoparticles embedded in a host material. It is shown that sensitivity and absorption of sensor depends on number and type of films. It theoretically analyzed that the different states such as, fiber-optic sensor with a single thin layer of spherical gold or silver nanoparticle and a bimetallic arrangement of silver and gold nanoparticles. It also studied dependence of the sensitivity and absorption of sensor on the parameters such as gold particle size, film thickness, refractive index of host material, sensing region length, fiber core diameter, maximum absorption wavelength, half maximum width of the sensing medium and background refractive index of the sensing layer.

Salari, M.; Askari, H. R.

2013-06-01

350

Nonlinear soliton matching between optical fibers.  

UK PubMed Central (United Kingdom)

In this Letter, we propose a generic nonlinear coupling coefficient, ?(NL)²=?|?/??|(fiber2)/|?/??|(fiber1), 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 self-frequency shift of a fundamental soliton, and we show that nonlinear matching can take precedence over linear mode matching. The nonlinear coupling coefficient depends on both the dispersion (??) and nonlinearity (?), as well as on the power coupling efficiency ?. Being generic, ?(NL) enables engineering of general waveguide systems, e.g., for optimized Raman redshift or supercontinuum generation.

Agger C; Sørensen ST; Thomsen CL; Keiding SR; Bang O

2011-07-01

351

Nonlinear soliton matching between optical fibers.  

Science.gov (United States)

In this Letter, we propose a generic nonlinear coupling coefficient, ?(NL)²=?|?/??|(fiber2)/|?/??|(fiber1), 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 self-frequency shift of a fundamental soliton, and we show that nonlinear matching can take precedence over linear mode matching. The nonlinear coupling coefficient depends on both the dispersion (??) and nonlinearity (?), as well as on the power coupling efficiency ?. Being generic, ?(NL) enables engineering of general waveguide systems, e.g., for optimized Raman redshift or supercontinuum generation. PMID:21725491

Agger, Christian; Sørensen, Simon T; Thomsen, Carsten L; Keiding, Søren R; Bang, Ole

2011-07-01

352

Optical fiber modulator derivates from hollow optical fiber with suspended core.  

UK PubMed Central (United Kingdom)

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 <120 ms. Significantly, this work presents information for the development of all-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.

Yang X; Liu Y; Tian F; Yuan L; Liu Z; Luo S; Zhao E

2012-06-01

353

Ammonia Optical Sensing by Microring Resonators  

Directory of Open Access Journals (Sweden)

Full Text Available A very compact (device area around 40 μm2) optical ammonia sensor based on amicroring resonator is presented in this work. Silicon-on-insulator technology is used insensor design and a dye doped polymer is adopted as sensing material. The sensor exhibitsa very good linearity and a minimum detectable refractive index shift of sensing materialas low as 8x10-5, with a detection limit around 4 ‰.

Vittorio M. N. Passaro; Francesco Dell’Olio; Francesco De Leonardis

2007-01-01

354

Optical Instruments for Remote Sensing from Space  

UK PubMed Central (United Kingdom)

This review covers the optical design of passive remote sensing optical instruments. Thereview concentrates on the design of spaceborne cameras and imagingspectrometers. The major designs that have been produced over the past years arediscussed, and new designs for future imaging spectrometers are presented.1.The purpose of this review is to cover the optical designs that have been developed forpassive sensing over the years. The review concentrates onthe design of cameras and imaging spectrometers used on spacecraft, withsome aircraft instruments for A list of the instruments covered isgiven in Table 1, together with acronyms and the to the papersdescribing The earlier remote sensing instruments arc well covered inbook.Passive instruments derive information from the scene by collecting thesolar radiation or emitted thermal radiation from each spatial area. Thisradiation is analyzed by the instrument for spectral content, and in some casesproperties.remote ...

Michael P

355

Principles and Applications of Fiber-Optic Sensors.  

Science.gov (United States)

Fiber-optic sensors are characterized by excellent insulation and noninductive characteristics and are inherently explosion-proof. The article describes how the authors developed fiber-optic temperature sensors using the temperature-dependent optical abso...

K. Kyuma S. Tai M. Nunoshita K. Sato K. Yoshinaga

1983-01-01

356

Compensated vibrating optical fiber pressure measuring device  

Energy Technology Data Exchange (ETDEWEB)

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.

Fasching, George E. (Morgantown, WV); Goff, David R. (Christiansburg, VA)

1987-01-01

357

Automated photosensitivity enhancement in optical fiber tapers  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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 (more) . 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.

Paterno, Aleksander Sade; Oliveira, Valmir de; Kalinowski, Hypolito J.

2011-06-01

358

Measurement of megampere currents with optical fibers  

Energy Technology Data Exchange (ETDEWEB)

Fiber optic sensors are routinely used to measure multi-megampere currents. The sensors are low noise, absolutely calibrated, and electrically decoupled from the pulsed power source. Polarized light from a HeNe laser is guided past the current carrier by a single-mode, low-birefringence fiber. The magnetic field from the current causes a Faraday rotation of the light polarization which is detected by a polarization analyzer and photodiode at the end of the fiber. A rotation of about 250/sup 0//MA +- 5%, slightly less than the Verdet constant for non-birefringent silica glass was observed. It was found that highly birefringent (polarization preserving) optical fibers do not work in this application. The sensor is being ruggedized for field use with high-explosive-driven current sources by using a diode laser and single mode fiber couplers to replace the laboratory system of lenses and spatial filters.

Veeser, L.; Kania, D.; Freeman, B.; Kruse, P.; Zimmerman, E.

1983-01-01

359

Fiber Optical Sensor for High Temperatures  

Directory of Open Access Journals (Sweden)

Full Text Available The fiber optic sensors are used in various industries. Advantages of optical sensors are based on the benefits of fiber and partially profit at their technological advances. The fiber optic temperature sensors are based on more than one way of scanning, all reach the upper scanning limit of about 600 °C. This article aims to introduce the principle of the sensor based on black body radiation. This type of sensor is difficult to specify precisely, it can not be easily classified into groups of intensity sensors or radiation sensors. At lower temperatures, it could be classified into intensity sensors, but at higher temperatures occurs to its own radiation of photons inside the fiber.

Frantisek Hanacek; Jan Latal; Petr Koudelka; Jan Skapa; Petr Siska; Vladimir Vasinek; Jan Hurta

2010-01-01

360

Optical fiber datalinks for nuclear instrument modules  

International Nuclear Information System (INIS)

[en] Optical fiber datalink modules have been developed for use with the NIM (Nuclear Instrument Module) bin. The module consists of an optical transmitter and receiver pair, an AC-DC converter, line drivers, photocouplers, and a pulse phase inverter circuit, which minimizes the pulse width distortion and the jitter in the datalink module tandem connection. One hundred and five modules were fabricated and installed in 3.1km fiber cables for 2.5 GeV Electron Linac (Linear Electron Accelerator) control data transmission in KEK - the National Laboratory for High Energy Physics, Tsukuba, Japan. Optical fiber cables were installed by the connectorized fiber cable installation method without splicing or connector field-assembling. The datalink system provided highly reliable data transmission in a large scale electromagnetic noise environment. (author)

1982-01-01

 
 
 
 
361

Lab-on-fiber technology: toward multifunctional optical nanoprobes.  

UK PubMed Central (United Kingdom)

We propose a reliable fabrication process enabling the integration of dielectric and metallic nanostructures on the tip of optical fibers, thus representing a further step in the "lab-on-fiber" technology roadmap. The proposed fabrication procedure involves conventional deposition and nanopatterning techniques, typically used for planar devices, but here adapted to directly operate on optical fiber tip. Following this approach, we demonstrate a first technological platform based on the integration onto the optical fiber tip of two-dimensional hybrid metallo-dielectric nanostructures supporting localized surface plasmon resonances. By means of experimental measurements and full-wave numerical simulations, we characterize these resonant phenomena and investigate the underlying physics. We show that resonances can be easily tuned by acting on the physical and geometrical parameters of the structure. Moreover, with a view toward possible applications, we present some preliminary results demonstrating how the proposed device can work effectively as an optical probe for label-free chemical and biological sensing as well as a microphone for acoustic wave detection.

Consales M; Ricciardi A; Crescitelli A; Esposito E; Cutolo A; Cusano A

2012-04-01

362

Nonlinear fiber-optic strain sensor based on four-wave mixing in microstructured optical fiber  

DEFF Research Database (Denmark)

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.

Gu, Bobo; Yuan, Scott Wu

2012-01-01

363

The Soliton Transmissions in Optical Fibers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 attracti...

Leos Bohac

364

Gas sensing using air-guiding photonic bandgap fibers  

DEFF Research Database (Denmark)

We demonstrate the high sensitivity of gas sensing using a novel air-guiding photonic bandgap fiber. The bandgap fiber is spliced to a standard single-mode fiber at the input end for easy coupling and filled with gas through the other end placed in a vacuum chamber. The technique is applied to characterize absorption lines of acetylene and hydrogen cyanide employing a tunable laser as light source. Measurements with a LED are also performed for comparison. Detection of weakly absorbing gases such as methane and ammonia is explored.

Ritar, Tuomo; Tuominen, J.

2004-01-01

365

Fiber-optic spectral-streak equalizer  

International Nuclear Information System (INIS)

[en] A spectral-streak equalizer was developed for use with an electronic streak camera to correct for material dispersion in optical fibers. Material dispersion occurs because different wavelengths of light travel at different speeds through glass fibers; the resulting difference in transit times broadens light pulses, which can lead to errors in certain scientific applications. This new instrument combines optical equalization and streak equalization techniques; it uses an array of optical fibers, as in the optical equalization technique, to partially compensate for the dispersion and uses the streak camera dynamics, as in the streak equalization technique, to complete the compensation. This paper examines the principles of equalization and compares several techniques, enumerates general and specific design considerations, outlines the calibration procedure, details efficiency estimates, describes testing techniques, gives calibration data and test results for spectral-streak equalizers currently in use, and draws conclusions from recent experience with these devices

1985-01-01

366

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)

1982-01-01

367

Optical characteristics of bending multimode superstructure fiber gratings.  

UK PubMed Central (United Kingdom)

The dispersion characteristics of superstructure fiber gratings written in multimode fibers and side-polished multimode fibers are investigated at different bending curvatures. The experimental results show that the group time delay in multimode superstructure fiber gratings can be tuned more easily than that of superstructure gratings in single-mode fiber. This method can provide tunable dispersion of superstructure fiber gratings by controlling the bending curvatures for application in dispersion compensators, fiber sensors, or suitable optical filters of optical communication systems.

Fu MY; Liu WF; Sheng HJ; Ai L; Peng HW; Tien CL

2009-09-01

368

Measurements of Magnetostriction of Metallic Glass Ribbons by Fiber-Optic Interferometry  

Energy Technology Data Exchange (ETDEWEB)

Magnetostrictions of metallic glass ribbons were measured by fiber-optic Mach-Zehnder interferometry. The saturation magnetostriction measured here are accurate to within 10%. For accurate measurements the fibers in the ribbons were uncoated, the ribbons were flattened before bonding, and two passes of fiber in the sensing arm were bonded to a single layer metallic glass ribbon at the ends only. Various factors affecting the accuracy of the measurements were also discussed. (author). 13 refs., 4 figs., 1 tab.

Lee, K.S.; Kim, M.H.; Kang, H.S. [Sung Kyun Kwan University, Suwon (Korea, Republic of); Park, M.Y. [SAMSUNG Electronics Co., Ltd. R and D Center (Korea, Republic of); Kim, T.K. [LG Information and Communications, Ltd. R and D Center (Korea, Republic of)

1997-12-01

369

Fiber-optic surface plasmon resonance sensor with multi-alternating metal layers for biological measurement  

Science.gov (United States)

Optical fiber based SPR sensors have attracted more and more attention due to their unique advantages over the prism-based SPR sensors. A novel fiber-optic SPR sensor with multi-alternating metal layers for biochemical analysis is presented in this paper. Based on the fundamental SPR theory of the fiber optic sensing technology, we theoretically investigated the effects of the existence of alternating layers deposited on sensing region SPR wavelength changes. The emphasis was placed on the numerical simulation of the fiber-optic SPR sensor's sensitivity which could be affected by its technical parameters such as the metal thickness, number of alternating layers. Results showed that, compared to the normal SPR sensor with the single metal layer, the proposed sensor had a wider detecting range of the refractive index and higher sensitivity, which can find applications in biological analysis.

Wang, Yanjie; Meng, Shengwei; Liang, Yuzhang; Li, Lixia; Peng, Wei

2013-09-01

370

Radiation resistant characteristics of optical fiber, 4  

International Nuclear Information System (INIS)

[en] 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.)

1985-01-01

371

Sensitivity of photonic crystal fiber grating sensors: biosensing, refractive index, strain, and temperature sensing  

CERN Document Server

We study the sensitivity of fiber grating sensors in the applications of strain, temperature, internal label-free biosensing, and internal refractive index sensing. It is shown that optical dispersion plays a central role in determining the sensitivity, and the dispersion may enhance or suppress sensitivity as well as change the sign of the resonant wavelength shifts. We propose a quality factor, $Q$, for characterizing LPGs.

Rindorf, Lars

2007-01-01

372

A Special Fiber Optic Sensor for Measuring Wheel Loads of Vehicles on Highways  

Directory of Open Access Journals (Sweden)

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.

Ramesh B. Malla; Amlan Sen; Norman W. Garrick

2008-01-01

373

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

Directory of Open Access Journals (Sweden)

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.

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

2010-01-01

374

Skew rays in optical fibers.  

UK PubMed Central (United Kingdom)

In order to justify the use of meridional analysis, the authors solve the Eikonal equation without approximationin two cases of index profile. Limit conditions are studied and attention is given to skew rays with inclination over the fiber axis greater than the critical angle of the meridional case. It is shown that skew rays introduce a queue in the impulse response of a fiber. In the case of solid state laser sources, they do not carry significant energy, and then can be neglected.

Cozannet A; Treheux M

1975-06-01

375

Fiber optically isolated and remotely stabilized data transmission system  

Energy Technology Data Exchange (ETDEWEB)

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.

Nelson, Melvin A. (Santa Barbara, CA)

1992-01-01

376

Fiber optics temperature and pressure probe  

Energy Technology Data Exchange (ETDEWEB)

The half life, the line width, and the ratio of peak intensities of the R/sub 1/ and R/sub 2/ ruby lines are only a function of temperature, while the shift in line position and the absolute intensities are functions of both the pressure and temperature. The emission from an optical fiber with a ruby tip encodes both the temperature and pressure of the fiber tip. Both the temperature and the pressure can be deduced by analyzing this spectroscopic information.

Hirschfeld, T.; Wang, F.; Haugen, G.; Hieftje, G.

1983-09-29

377

Fiber-optic polarizing directional coupler.  

UK PubMed Central (United Kingdom)

A novel fiber-optic device acting simultaneously as a polarizer and a directional coupler is fabricated by coating a metal layer onto the fused biconical-taper structure of single-mode fibers. This polarizing directional coupler exhibits an extinction ratio of 15 dB together with a 1:1 power-splitting ratio and an excess loss of 2.8 dB.

Kawachi M; Kobayashi M

1984-05-01

378

Optical Fiber for High-Power Optical Communication  

Directory of Open Access Journals (Sweden)

Full Text Available We examined optical fibers suitable for avoiding such problems as the fiber fuse phenomenon and failures at bends with a high power input. We found that the threshold power for fiber fuse propagation in photonic crystal fiber (PCF) and hole-assisted fiber (HAF) can exceed 18 W, which is more than 10 times that in conventional single-mode fiber (SMF). We considered this high threshold power in PCF and HAF to be caused by a jet of high temperature fluid penetrating the air holes. We showed examples of two kinds of failures at bends in conventional SMF when the input power was 9 W. We also observed the generation of a fiber fuse under a condition that caused a bend-loss induced failure. We showed that one solution for the failures at bends is to use optical fibers with a low bending loss such as PCF and HAF. Therefore, we consider PCF and HAF to be attractive solutions to the problems of the fiber fuse phenomenon and failures at bends with a high power input.

Kenji Kurokawa

2012-01-01

379

Quantum cryptography over underground optical fibers  

Energy Technology Data Exchange (ETDEWEB)

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.``

Hughes, R.J.; Luther, G.G.; Morgan, G.L.; Peterson, C.G.; Simmons, C.

1996-05-01

380

Hot Springs-Garrison Fiber Optic Project  

Energy Technology Data Exchange (ETDEWEB)

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.

1994-10-01

 
 
 
 
381

A Borehole Fiber-Optic Strainmeter  

Science.gov (United States)

The SAFOD project provides an opportunity to study the basic mechanics of a fault that undergoes relatively frequent events. Magnitude 2 earthquakes within a few km of the borehole occur several times per year and produce strain signals on the order of a nanostrain. We installed a vertical fiber-optic strainmeter in the annulus of cement between the inner and outer casings of the borehole. The sensor consists of an optical fiber cable stretched from the surface to a depth of 864 m. The optical length of the fiber is monitored with a laser interferometer sampled at 50,000 samples per second. The strainmeter noise is about 0.01 nanostrain at 1 Hz, which provides clear records of coseismic offsets.

Zumberge, M. A.

2005-12-01

382

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

1994-01-01

383

Fiber optic probe for light scattering measurements  

Energy Technology Data Exchange (ETDEWEB)

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.

Nave, Stanley E. (Evans, GA); Livingston, Ronald R. (Aiken, SC); Prather, William S. (Augusta, GA)

1995-01-01

384

Fiber optic probe for light scattering measurements  

Energy Technology Data Exchange (ETDEWEB)

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.

Nave, S.E.; Livingston, R.R.; Prather, W.S.

1993-01-01

385

Launching condition effect on CMC detecting optical fiber sensor based on the adsorption effect  

International Nuclear Information System (INIS)

[en] In this paper an optical fiber sensor for detection of critical micelle concentration (CMC) is described. The sensor is based on evanescent wave phenomenon. The evanescent wave interacts with modules approaching the interface of the core cladding from the cladding side. When surfactant molecules adsorb onto the sensing region of the fiber, the optical output increases. When the concentration of surfactant solution reaches CMC and surfactants adsorb uniformly onto the sensing region, the output of the fiber increases abruptly. With the use of this phenomenon the sensor is able to detect the CMC of surfactant solution in real time instead of other methods , such as surface tension and electrical conductivity. In this paper the effect of launching condition of the light and interaction length of the sensing region on sensor sensitivity is described and it has been shown that selective rays launching and long interaction length of the sensing region improved the sensor sensitivity (Authors)

2002-01-01

386

Concentric core optical fiber with multiple-mode signal transmission  

Energy Technology Data Exchange (ETDEWEB)

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.

Muhs, Jeffrey D. (Lenoir City, TN)

1997-01-01

387

Durability tests of a fiber optic corrosion sensor.  

UK PubMed Central (United Kingdom)

Steel corrosion is a major cause of degradation in reinforced concrete structures, and there is a need to develop cost-effective methods to detect the initiation of corrosion in such structures. This paper presents a low cost, easy to use fiber optic corrosion sensor for practical application. Thin iron film is deposited on the end surface of a cleaved optical fiber by sputtering. When light is sent into the fiber, most of it is reflected by the coating. If the surrounding environment is corrosive, the film is corroded and the intensity of the reflected signal drops significantly. In previous work, the sensing principle was verified by various experiments in laboratory and a packaging method was introduced. In this paper, the method of multiplexing several sensors by optical time domain reflectometer (OTDR) and optical splitter is introduced, together with the interpretation of OTDR results. The practical applicability of the proposed sensors is demonstrated in a three-year field trial with the sensors installed in an aggressive marine environment. The durability of the sensor against chemical degradation and physical degradation is also verified by accelerated life test and freeze-thaw cycling test, respectively.

Wan KT; Leung CK

2012-01-01

388

Durability Tests of a Fiber Optic Corrosion Sensor  

Directory of Open Access Journals (Sweden)

Full Text Available Steel corrosion is a major cause of degradation in reinforced concrete structures, and there is a need to develop cost-effective methods to detect the initiation of corrosion in such structures. This paper presents a low cost, easy to use fiber optic corrosion sensor for practical application. Thin iron film is deposited on the end surface of a cleaved optical fiber by sputtering. When light is sent into the fiber, most of it is reflected by the coating. If the surrounding environment is corrosive, the film is corroded and the intensity of the reflected signal drops significantly. In previous work, the sensing principle was verified by various experiments in laboratory and a packaging method was introduced. In this paper, the method of multiplexing several sensors by optical time domain reflectometer (OTDR) and optical splitter is introduced, together with the interpretation of OTDR results. The practical applicability of the proposed sensors is demonstrated in a three-year field trial with the sensors installed in an aggressive marine environment. The durability of the sensor against chemical degradation and physical degradation is also verified by accelerated life test and freeze-thaw cycling test, respectively.

Kai Tai Wan; Christopher K.Y. Leung

2012-01-01

389

Application of optical fibers in microfluidic structures  

Science.gov (United States)

Two constructions of microfluidic structures are described in this paper. A fiber optic chemical coupler and a microcell for spectrophotometric measurements were designed and tested. The structures were made of polymer optical fibers (PMMA) which were incorporated into polymeric material i.e. poly(dimethylsiloxane). The structures were tested as detectors in refractometric experiment (saccharose solutions with different concentrations were used), in absorbance measurement (solutions of a bromothymol blue with different pH were used) and in fluorescence tests (solution of erythrosine was used).

Stadnik, Dorota; Brzozka, Zbigniew; Dybko, Artur

2004-09-01

390

Lasers and optical fibers in medicine  

CERN Multimedia

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

Katzir, Abraham

1993-01-01

391

An optical fiber readout for scintillator calorimeters  

International Nuclear Information System (INIS)

[en] A method is described for collecting light from scintillation-counter calorimeters by means of an optical fiber connected to a wavelength shifter, covering an edge of a scintillator plate. The optical fiber passes between the continuous metallic plates and guides the light to a photomultiplier. The measurements with a prototype electromagnetic calorimeter give the energy resolution 8% (fwhm) at 26 GeV electron energy and uniformity across the surface of the calorimeter +-6%. The proposed method has a number of new advantages. (orig.)

1986-07-01

392

Fiber-optic vector vibroscope.  

UK PubMed Central (United Kingdom)

A directional vibration sensor based on polarization-controlled cladding-to-core recoupling is demonstrated. A compact structure in which a short section of multi-mode fiber (MMF) stub containing a weakly tilted fiber Bragg grating (TFBG) is spliced to another single-mode fiber without any lateral offset. Multiple core modes of the MMF are coupled at the junction and appear as well defined resonances in reflection from the TFBG. Some of those resonances exhibit a strong polarization and bending dependence. Both the orientation and the amplitude of the vibrations can be determined unambiguously via dual-path power detection of the orthogonal-polarimetric lowest order LP(1n) modes. Meanwhile, the unwanted power fluctuations and temperature perturbations can be referenced out by monitoring the fundamental LP(01) mode resonance.

Guo T; Shang L; Ran Y; Guan BO; Albert J

2012-07-01

393

Gaseous ammonia fluorescence probe based on cellulose acetate modified microstructured optical fiber  

Science.gov (United States)

In this article, we report a novel fluorescent ammonia gas probe based on microstructured optical fiber (MOF) which is modified with eosin-doped cellulose acetate film. This probe was fabricated by liquid fluxion coating process. Polymer solution doped with eosin was directly inhaled into 18 array holes of MOF and then formed matrix film in them. The sensing properties of the optical fiber sensor to gaseous ammonia at room temperature were investigated. The sensing probe showed different fluorescence intensity at 576 nm to different concentrations of trace ammonia in carrier gas of nitrogen. The response range was 50-400 ppm, with short response time within 500 ms. Furthermore, the response range could be tailored through CTAB co-entrapment process in the sensing film. These test results demonstrated that low cost, simple structured fiber optic sensors for detecting ammonia gas samples could be developed based on MOF.

Peng, Lirong; Yang, Xinghua; Yuan, Libo; Wang, Lili; Zhao, Enming; Tian, Fengjun; Liu, Yanxin

2011-09-01

394

Optical fiber sensors for smart materials characterization  

Energy Technology Data Exchange (ETDEWEB)

Optical and optical fiber methods may be used to characterize materials and structures. Their advantages for such applications include their immunity to electromagnetic interference, high sensitivity, resolution and dynamic range, and ability to operate in harsh environmental conditions. This paper describes the application of such methods to the characterization of smart materials and structures during their fabrication, in-service lifetime, and damage and degradation.

Claus, R.O. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Electrical Engineering Dept.

1994-12-31

395

A novel optical fibers MEMS pressure sensor  

International Nuclear Information System (INIS)

[en] A novel pressure sensor based on the Fabry-Perot interferometry and microelectromechanical system (MEMS) technology is proposed and demonstrated. Light is coupled into the sensor through a fiber. Dual-wavelength demodulation method is used to analyze the reflected optical signals and compensate the errors independent of optical wavelength. Theoretical analysis and simulation results are presented. Experimental results for pressure measurements ranging from 0 Mpa to 3 Mpa demonstrate reasonable linearity and sensitivity

2006-04-01

396

Is Polar Bear Hair Fiber Optic?  

Science.gov (United States)

New direct measurement of high optical attenuation rates in polar bear hairs 2 8 dB mm in the visible and reanalysis of the data of Tributsch et al . Sol. Energy Mater. 21, 219 (1990) seem to rule out the UV waveguiding proposed by Grojean et al . Appl. Opt. 19, 339 (1980) . The case against fiber-optic polar bear hairs is summarized, and four conditions are given that any variation of the model of Grojean et al . would have to satisfy.

Koon, Daniel W.

1998-05-01

397

Silicon optical fiber diameter dependent grain size  

Science.gov (United States)

In the fabrication of silicon optical fibers, there is a need to understand the dependency of the grain size of the silicon core and the processing parameters during the fabrication process. This study was undertaken to determine how the grain size in the core structure varied with changes in the fabrication parameters during drawing of the silicon optical fibers. The primary fabrication variables' changes were preform dimension and drawing speed, resulting in fibers of varying diameters in both the core and cladding regions. Grain size and orientation of the silicon core of the resultant fiber was determined using Electron Backscatter Diffraction (EBSD). Grain size was normalized to the core diameter and it was found that the grain size or the length of the grain within the core increased as the diameter of the core increased. No preferential grain orientation was observed in any of the fibers. Grain length increases as the diameter increases and the rate of cooling decreases as the diameter increases. This decrease in cooling rate reduces the nucleation rate of grains during solidification process as the fibers are being drawn.

Scott, Brian L.; Pickrell, Gary R.

2013-05-01

398

Recent advances in fiber-optic DNA biosensors  

Directory of Open Access Journals (Sweden)

Full Text Available Fiber-optic DNA biosensors are a kind of ana-lytic setups, which convert the Waston-Crick base pairs matching duplex or Hoogsteen’s tri-plex (T/A-T, C/G-C) formation into a readable analytical signals when functionalized single- strands DNA (ssDNA) or double-strands DNA (dsDNA) of interest are immobilized on the sur-face of fiber-optic hybrids with target DNA or interacts with ligands. This review will provide the information about the fiber-optic DNA bio-sensors classified into two categories depend-ing on the end fiber and side fiber with or with-out the labels—label-free fiber-optic DNA bio-sensors and labeled fiber-optic DNA biosensor in recent years. Both are dissertated, and em-phasis is on the label-free fiber-optic DNA bio-sensors. Fiber-optic DNA biosensors had got great progresses because fiber-optic has more advantages over the other transducers and are easily processed by nanotechnology. So fiber- optic DNA biosensors have increasingly at-tracted more attention to research and develop the new fiber-optic DNA biosensors that inte-grated with the “nano-bio-info” technology for in vivo test, single molecular detection and on-line medical diagnosis. Finally, future pros-pects to the fiber-optic DNA biosensors are predicted.

Yi-Ming Wang; Xiao-Feng Pang; Yu-Yu Zhang

2009-01-01

399

Fiber optic micro sensor for the measurement of tendon forces  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract A fiber optic sensor developed for the measurement of tendon forces was designed, numerically modeled, fabricated, and experimentally evaluated. The sensor incorporated fiber Bragg gratings and micro-fabricated stainless steel housings. A fiber Bragg grating is an optical device that is spectrally sensitive to axial strain. Stainless steel housings were designed to convert radial forces applied to the housing into axial forces that could be sensed by the fiber Bragg grating. The metal housings were fabricated by several methods including laser micromachining, swaging, and hydroforming. Designs are presented that allow for simultaneous temperature and force measurements as well as for simultaneous resolution of multi-axis forces. The sensor was experimentally evaluated by hydrostatic loading and in vitro testing. A commercial hydraulic burst tester was used to provide uniform pressures on the sensor in order to establish the linearity, repeatability, and accuracy characteristics of the sensor. The in vitro experiments were performed in excised tendon and in a dynamic gait simulator to simulate biological conditions. In both experimental conditions, the sensor was found to be a sensitive and reliable method for acquiring minimally invasive measurements of soft tissue forces. Our results suggest that this sensor will prove useful in a variety of biomechanical measurements.

Behrmann Gregory P; Hidler Joseph; Mirotznik Mark S

2012-01-01

400

Torsion sensing with a fiber ring laser incorporating a pair of rotary long-period fiber gratings  

Science.gov (United States)

We experimentally demonstrate a fiber ring laser for high-resolution torsion measurement, where the laser cavity consists of a Mach-Zehnder interferometer formed with a pair of long-period fiber gratings written in a twisted single-mode fiber by a CO2 laser. The emitting wavelength of the laser provides a measure of the rate of the torsion applied to the grating pair, while the direction of the wavelength shift indicates the sense of the applied torsion. The narrow linewidth and the large side-mode suppression ratio of the laser can provide a much more precise measurement of torsion, compared with passive fiber-optic torsion sensors. The torsion sensitivity achieved is 0.084 nm/(rad/m) in the torsion range ± 100 rad/m, which corresponds to a torsion resolution of 0.12 rad/m, assuming a wavelength resolution of 10 pm for a typical optical spectrum analyzer. The ultimate resolution of the sensor is limited by the linewidth of the laser and could be an order of magnitude higher.

Shi, Leilei; Zhu, Tao; Fan, Yan-En; Chiang, Kin Seng; Rao, Yunjiang

2011-10-01

 
 
 
 
401

Specific signal processing method for sound detected by an intrinsic optical fiber sensor  

Science.gov (United States)

Intrinsic optical fiber microphones with the design that we propose have a good sensitivity and dynamic allowing them to address many innovative applications. But their performances induce some defects as noise sensing that has to be separated to the wanted sound signal to obtain a clean usable sound signal. In this paper we introduce the design of an optical fiber sound sensing system and the bases of the adapted signal processing allowing to use all the advantages of this design with a low level of noise. The results are very promising.

Arezki, M.; Meyrueis, P.; Javahiraly, N.

2010-04-01

402

Fiber optic current sensor with Heterodyne detection  

International Nuclear Information System (INIS)

This paper discusses the toroidal plasma current in the ZT-40M experiment (100-380 kA) measured using a fiber optic sensor. This sensor consists of six turns of permanently twisted, single mode fiber which was wound poloidally around the experiment. By modifying the laser output to a rotating linear polarization, amplitude independent single output heterodyne detection is possible. The signal is proportional to the B field produced by the plasma current so integration of the data is not required to obtain the current. Comparison with the existing Rogowski coil consistently shows less than 1% difference. Present efforts are directed toward simplifying the design to minimize optical alignment and to implement real time digital data reduction. The fiber current sensor has demonstrated accuracy comparable with existing techniques. It possesses broad frequency response, it eliminates insulation, electromagnetic interference, and ground loop problems and can easily be installed on existing plasma experiments.

1986-01-01

403

SOFI: A scintillating optical fiber imager  

International Nuclear Information System (INIS)

[en] We present characteristics of a charged particle detector which combines optical fibers with a multianode photomultiplier. Our first prototype allows detection of 32P emitters on a 26x26 cm2 surface with 1.5 mm and 5 mm resolutions, respectively for X and Y directions, and a 0.3% efficiency. Improvements, presently under study, in both fiber qualities and photocathode efficiency should increase the device efficiency to 40% and its resolution up to the optical fiber diameter (500 ?m for the time being). Such characteristics would allow SOFI to replace autoradiographic films in biology and make it a convenient position sensitive detector in nuclear and particle physics. (orig.)

1988-12-15

404

High temperature, minimally invasive optical sensing modules  

Energy Technology Data Exchange (ETDEWEB)

A remote temperature sensing system includes a light source selectively producing light at two different wavelengths and a sensor device having an optical path length that varies as a function of temperature. The sensor receives light emitted by the light source and redirects the light along the optical path length. The system also includes a detector receiving redirected light from the sensor device and generating respective signals indicative of respective intensities of received redirected light corresponding to respective wavelengths of light emitted by the light source. The system also includes a processor processing the signals generated by the detector to calculate a temperature of the device.

Riza, Nabeel Agha (Oviedo, FL); Perez, Frank (Tujunga, CA)

2008-02-05

405

Optical fibers by butyl methacrylate reactive extrusion  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A process for a poly(butyl methacrylate) optical fibers production by reactive extrusion was developed. The reactive system was adapted to the reduced reaction time in the extruder combining concepts based on the free volume theory and a kinetic model for mass polymerization a butyl methacrylate. A ...

Berthet, Romuald; Chalamet, Yvan; Taha, Mohamed; Zerroukhi, Amar

406

Recipe for Soliton Robustness in Optical Fibers.  

Science.gov (United States)

It is often claimed in the literature that solitons in optical fibers are well-described by the nonlinear Schroedinger equation. The evidence for this claim is the remarkable series of experiments, dating from the original work of Mollenauer, et al., whic...

C. R. Menyuk

1992-01-01

407

Implementation guidance for fiber optic loop sensors  

Energy Technology Data Exchange (ETDEWEB)

Fiber optic loop sensors are a form of active security seal that can be used for detecting attempts to move or access secured items. This document is a guide that provides information about this type of sensor and suggests possible implementations.

Swank, R.G.. Westinghouse Hanford

1996-05-30

408

Fiber Laser Coupled Optical Spark Delivery System.  

Science.gov (United States)

A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to ...

A. Yalin B. Willson M. Defoort S. Joshi A. Reynolds

2005-01-01

409

Cascaded Bragg scattering in fiber optics.  

UK PubMed Central (United Kingdom)

We report on a theoretical and experimental study of cascaded Bragg scattering in fiber optics. We show that the usual energy-momentum conservation of Bragg scattering can be considerably relaxed via cascade-induced phase-matching. Experimentally we demonstrate frequency translation over six- and 11-fold cascades, in excellent agreement with derived phase-matching conditions.

Xu YQ; Erkintalo M; Genty G; Murdoch SG

2013-01-01

410

FIBER OPTIC BIOSENSOR FOR DNA DAMAGE  

Science.gov (United States)

This paper describes a fiber optic biosensor for the rapid and sensitive detection of radiation-induced or chemically-induced oxidative DNA damage. The assay is based on the hybridization and temperature-induced dissociation (melting curves) of synthetic oligonucleotides. The...

411

Low attenuation optical fiber of deuterated polymer  

Energy Technology Data Exchange (ETDEWEB)

Light-transmitting optical fiber having a core of a (deuterated acrylate) polymer selected from the group consisting of a deuterated methacrylate homopolymer, a deuterated methacrylate copolymer and a deuterated methacrylate/acrylate copolymer which exhibits remarkably high transmission of light in the visible and at certain wavelengths in the near-infrared region of the spectrum.

Beasley, J.K.; Beckerbauer, R.; Schleinitz, H.M.; Wilson, F.C.

1985-04-16

412

Fiber optics and their applications in nuclear power plants  

International Nuclear Information System (INIS)

[en] Naturally, technical innovation and advanced technology give large impact also to the technical field of atomic energy, and the examples are the introduction of computers and optical information transmission and processing technology into atomic energy facilities. Combined with the development of radiation-resistant optical fibers, the optical information technology has been introduced into all aspects of atomic energy field. The information transmission using optical fibers is advantageous because of wide band, small loss, the immunity to crosstalk and electromagnetic induction effects, small size and low price. The structure of optical fibers, the transmission loss in optical fibers, the manufacturing method for optical fibers, the coating structure for optical fibers, optical cable structure, the new optical fibers developed recently such as optical fiber image guides, constant polarization fibers and infrared fibers, the merits of using optical fibers for signal transmission, atomic energy facilities and image transmission, the present status of the research on radiation-resistant fibers, and the application to nuclear power stations, reprocessing plants, FBRs, fusion reactors and others are described. (Kako, I.)

1985-01-01

413

Implementation of Dual Use Fiber Optic Communications Laboratories  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Given the wide use of fiber optic technology in industry and high-end consumer electronics, the use of optical fiber should be more widely taught; however, limited available resources in the provision of laboratory hardware has increasingly marginalized the educational quality of fiber optic communi...

Akram Ahmad Abu-aisheh; Sameer Khader; Omar Hasan

414

SWCNTs-based nanocomposites as sensitive coatings for advanced fiber optic chemical nanosensors  

Science.gov (United States)

In this work, the feasibility of exploiting novel Cadmium Arachidate (CdA)/single-walled carbon nanotubes (SWCNTs) based composites as sensitive coatings for the development of robust and high performances optoelectronic chemosensors able to work in liquid environments has been investigated and proved. Here, nano-composite sensing layers have been transferred upon the distal end of standard optical fibers by the Langmuir-Blodgett (LB) technique. Reflectance measurements have been carried out to monitor ppm concentration of chemicals in water through the changes in the optical and geometrical features of the sensing overlay induced by the interaction with the analyte molecules. Preliminary experimental results evidence that such nanoscale coatings integrated with the optical fiber technology offers great potentialities for the room temperature detection of chemical traces in water and lead to significant improvements of the traditional fiber optic sensors based on SWCNTs layers.

Consales, M.; Crescitelli, A.; Penza, M.; Aversa, P.; Giordano, M.; Cutolo, A.; Cusano, A.

2008-05-01

415

Fiber-optic-based surface plasmon resonance (SPR) sensors for the detection of toxic nerve agents  

Science.gov (United States)

Analytical instruments capable of detecting nerve agents in battlefield conditions where speed, accuracy and ease of operation are a must in today's military. Fast detection and decontamination of nerve agents in very low concentrations is the primary focus of our research. The method presented here focuses on optimizing polymer stabilized sensing elements on the surface of SPR fiber-optic probes. A number of polymers & polymer supported metal complexes capable of reversibly binding to the species of interest & which have robust operation in hostile environments are incorporated with the fiber optic sensing elements. An optical technique, such as Surface Plasmon Resonance (SPR), better suited to rapid data collection without sample pretreatment is employed. The approach using polymer-based optical fibers with off-the-shelf SPR system components has been tested for the detection of Pinacolyl methylphosphonate (PMP), a simulant for nerve agent Soman. Surface initiated polymeric sensors have higher sensitivity toward detecting PMP than bulk-polymerized sensors.

Prakash, Anna M. C.; Kim, Yoon-Chang; Banerji, Soame; Masson, Jean-Francois; Booksh, Karl S.

416

Using a Fiber Loop and Fiber Bragg Grating as a Fiber Optic Sensor to Simultaneously Measure Temperature and Displacement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study integrated a fiber loop manufactured by using commercial fiber (SMF-28, Corning) and a fiber Bragg grating (FBG) to form a fiber optic sensor that could simultaneously measure displacement and temperature. The fiber loop was placed in a thermoelectric cooling module with FBG affixed to th...

Yao-Tang Chang; Chih-Ta Yen; Yue-Shiun Wu; Hsu-Chih Cheng

417

Polymer Fibers for Nonlinear Optics.  

Science.gov (United States)

The goal of our research is to assess the possibility of making an ultrafast all-optical switching device. This require the preliminaries of doing materials processing, materials characterization, and making all-device component structures such as single ...

M. G. Kuzyk

1996-01-01

418

Method for the continuous processing of hermetic fiber optic components and the resultant fiber optic-to-metal components  

Energy Technology Data Exchange (ETDEWEB)

Hermetic fiber optic-to-metal components and method for making hermetic fiber optic-to-metal components by assembling and fixturing elements comprising a metal shell, a glass preform, and a metal-coated fiber optic into desired relative positions and then sealing said fixtured elements preferably using a continuous heating process. The resultant hermetic fiber optic-to-metal components exhibit high hermeticity and durability despite the large differences in thermal coefficients of expansion among the various elements.

Kramer, Daniel P. (Centerville, OH)

1994-08-09

419

Use of High Spatial Resolution Fiber-Optic Shape Sensors to Monitor the Shape of Deployable Space Structures  

Science.gov (United States)

We report the use of a fiber-optic distributed sensing system to monitor the shape of light-weight deployable space structures. This technique involves using optical frequency domain reflectometry to demodulate the reflected signal from multiplexed Bragg gratings that have been photoetched in the core of an optical fiber. In this work, high-resolution optical shape sensors were applied to the surface of isogrid booms and used to monitor the shape of the structure subjected to various static and dynamic loading conditions. Data from the fiber-optic sensors correlates strongly with expected results.

Duncan, Roger G.; Raum, Matthew T.; Cadogan, David P.; Blandino, Joseph R.

2005-02-01

420

Sollektor: progress in fiber optic daylighting  

Science.gov (United States)

Directly using sunlight for the illumination of rooms that have no windows is a very important measure for higher energy efficiency and CO2 reduction in the next future, especially for countries along the sunny belt. The Sollektor ®, developed at the Polymer Optical Fiber Application Center in Nuernberg, Germany, offers an efficient way to do that. The Sollektor is a combination of a plastic injection moulded concentrator optics array, a control unit which tracks the sun over the day and a polymer optical fiber bundle, guiding the collected light into the rooms. In order to ensure the illumination even at times without sun we present concepts and first results for the combination with conventional LED in order to obtain a 24 hillumination on a high efficiency level with high quality light.

Poisel, H.; Hofbeck, K.; Bloos, M.; Lippenberger, M.; Schuetz, S.; Kist, A.

2012-10-01

 
 
 
 
421

Hydrostatic Pressure Sensing with High Birefringence Photonic Crystal Fibers  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of hydrostatic pressure on the waveguiding properties of high birefringence photonic crystal fibers (HiBi PCF) is evaluated both numerically and experimentally. A fiber design presenting form birefringence induced by two enlarged holes in the innermost ring defining the fiber core is investigated. Numerical results show that modal sensitivity to the applied pressure depends on the diameters of the holes, and can be tailored by independently varying the sizes of the large or small holes. Numerical and experimental results are compared showing excellent agreement. A hydrostatic pressure sensor is proposed and demonstrated using an in-fiber modal interferometer where the two orthogonally polarized modes of a HiBi PCF generate fringes over the optical spectrum of a broad band source. From the analysis of experimental results, it is concluded that, in principle, an operating limit of 92 MPa in pressure could be achieved with 0.0003% of full scale resolution.

Fernando C. Fávero; Sully M. M. Quintero; Cicero Martelli; Arthur M.B. Braga; Vinícius V. Silva; Isabel C. S. Carvalho; Roberth W. A. Llerena; Luiz C. G. Valente