Elasto-plastic bond mechanics of embedded fiber optic sensors in concrete under uniaxial tension with strain localization

Science.gov (United States)

Li, Qingbin; Li, Guang; Wang, Guanglun

2003-12-01

Brittleness of the glass core inside fiber optic sensors limits their practical usage, and therefore they are coated with low-modulus softer protective materials. Protective coatings absorb a portion of the strain, and hence part of the structural strain is sensed. The study reported here corrects for this error through development of a theoretical model to account for the loss of strain in the protective coating of optical fibers. The model considers the coating as an elasto-plastic material and formulates strain transfer coefficients for elastic, elasto-plastic and strain localization phases of coating deformations in strain localization in concrete. The theoretical findings were verified through laboratory experimentation. The experimental program involved fabrication of interferometric optical fiber sensors, embedding within mortar samples and tensile tests in a closed-loop servo-hydraulic testing machine. The elasto-plastic strain transfer coefficients were employed for correction of optical fiber sensor data and results were compared with those of conventional extensometers.

Feasibility Study on the Development of 2-channel Embedded Infrared Fiber-optic Sensor for Thermometry of Secondary Water System in Nuclear Power Plant

International Nuclear Information System (INIS)

Yoo, W. J.; Jang, K. W.; Seo, J. K.; Moon, J.; Han, K. T.; Lee, B.; Park, B. G.

2011-01-01

Any warm object by measuring the emitted infrared (IR) radiation. The radiometers using infrared optical fibers are based on the relationship between the temperature of a heat source and the quality and the quantity of an IR radiation. To measure physical properties including a temperature, optical fiber-based sensor has many advantages, such as small size, low cost, high resolution, remote sensing and immunity to electromagnetic radiation over conventional electrical sensors. In this study, we carried out the feasibility study on the development of an embedded IR fiber-optic sensor for thermometry of the secondary water system in a nuclear power plant. The 2-channel embedded fiberoptic temperature sensor was fabricated using two identical IR optical fibers for accurate thermometry without complicated calibration processes. To decide accurate temperature of the water, we measured the difference between the IR radiations emitted from the two temperature sensing probes according to the temperature variation of the water

Evaluations of fiber optic sensors for interior applications

Energy Technology Data Exchange (ETDEWEB)

Sandoval, M.W.; Malone, T.P.

1996-02-01

This report addresses the testing and evaluation of commercial fiber optic intrusion detection systems in interior applications. The applications include laying optical fiber cable above suspended ceilings to detect removal of ceiling tiles, embedding optical fibers inside a tamper or item monitoring blanket that could be placed over an asset, and installing optical fibers on a door to detect movement or penetration. Detection capability of the fiber optic sensors as well as nuisance and false alarm information were focused on during the evaluation. Fiber optic sensor processing, system components, and system setup are described.

Low Cost Plastic Optical Fiber Pressure Sensor Embedded in Mattress for Vital Signal Monitoring.

Science.gov (United States)

Sartiano, Demetrio; Sales, Salvador

2017-12-13

The aim of this paper is to report the design of a low-cost plastic optical fiber (POF) pressure sensor, embedded in a mattress. We report the design of a multipoint sensor, a cheap alternative to the most common fiber sensors. The sensor is implemented using Arduino board, standard LEDs for optical communication in POF (λ = 645 nm) and a silicon light sensor. The Super ESKA ® plastic fibers were used to implement the fiber intensity sensor, arranged in a 4 × 4 matrix. During the breathing cycles, the force transmitted from the lungs to the thorax is in the order of tens of Newtons, and the respiration rate is of one breath every 2-5 s (0.2-0.5 Hz). The sensor has a resolution of force applied on a single point of 2.2-4.5%/N on the normalized voltage output, and a bandwidth of 10 Hz, it is then suitable to monitor the respiration movements. Another issue to be addressed is the presence of hysteresis over load cycles. The sensor was loaded cyclically to estimate the drift of the system, and the hysteresis was found to be negligible.

Low Cost Plastic Optical Fiber Pressure Sensor Embedded in Mattress for Vital Signal Monitoring

Directory of Open Access Journals (Sweden)

Demetrio Sartiano

2017-12-01

Full Text Available The aim of this paper is to report the design of a low-cost plastic optical fiber (POF pressure sensor, embedded in a mattress. We report the design of a multipoint sensor, a cheap alternative to the most common fiber sensors. The sensor is implemented using Arduino board, standard LEDs for optical communication in POF (λ = 645 nm and a silicon light sensor. The Super ESKA® plastic fibers were used to implement the fiber intensity sensor, arranged in a 4 × 4 matrix. During the breathing cycles, the force transmitted from the lungs to the thorax is in the order of tens of Newtons, and the respiration rate is of one breath every 2–5 s (0.2–0.5 Hz. The sensor has a resolution of force applied on a single point of 2.2–4.5%/N on the normalized voltage output, and a bandwidth of 10 Hz, it is then suitable to monitor the respiration movements. Another issue to be addressed is the presence of hysteresis over load cycles. The sensor was loaded cyclically to estimate the drift of the system, and the hysteresis was found to be negligible.

Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments

Energy Technology Data Exchange (ETDEWEB)

Wang, Anbo [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

2016-09-30

This report summarizes technical progress on the program “Embedded Active Fiber Optic Sensing Network for Structural Health Monitoring in Harsh Environments” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology at Virginia Tech. The objective of this project is to develop a first-of-a-kind technology for remote fiber optic generation and detection of acoustic waves for structural health monitoring in harsh environments. During the project period, which is from April 1, 2013 to Septemeber 30, 2016, three different acoustic generation mechanisms were studied in detail for their applications in building a fiber optic acoustic generation unit (AGU), including laser induced plasma breakdown (LIP), Erbium-doped fiber laser absorption, and metal laser absorption. By comparing the performance of the AGUs designed based on these three mechanisms and analyzing the experimental results with simulations, the metal laser absorption method was selected to build a complete fiber optic structure health monitoring (FO-SHM) system for the proposed high temperature multi-parameter structure health monitoring application. Based on the simulation of elastic wave propagation and fiber Bragg grating acoustic pulse detection, an FO-SHM element together with a completed interrogation system were designed and built. This system was first tested on an aluminum piece in the low-temperature range and successfully demonstrated its capability of multi-parameter monitoring and multi-point sensing. In the later stages of the project, the research was focused on improving the surface attachment design and preparing the FO-SHM element for high temperature environment tests. After several upgrades to the surface attachment methods, the FO-SHM element was able to work reliably up to 600oC when attached to P91 pipes, which are the target material of this project. In the final stage of this project, this FO

Embedded Fiber Optic Sensors for Measuring Transient Detonation/Shock Behavior;Time-of-Arrival Detection and Waveform Determination.

Energy Technology Data Exchange (ETDEWEB)

Chavez, Marcus Alexander; Willis, Michael David; Covert, Timothy Todd

2014-09-01

The miniaturization of explosive components has driven the need for a corresponding miniaturization of the current diagnostic techniques available to measure the explosive phenomena. Laser interferometry and the use of spectrally coated optical windows have proven to be an essential interrogation technique to acquire particle velocity time history data in one- dimensional gas gun and relatively large-scale explosive experiments. A new diagnostic technique described herein allows for experimental measurement of apparent particle velocity time histories in microscale explosive configurations and can be applied to shocks/non-shocks in inert materials. The diagnostic, Embedded Fiber Optic Sensors (EFOS), has been tested in challenging microscopic experimental configurations that give confidence in the technique's ability to measure the apparent particle velocity time histories of an explosive with pressure outputs in the tenths of kilobars to several kilobars. Embedded Fiber Optic Sensors also allow for several measurements to be acquired in a single experiment because they are microscopic, thus reducing the number of experiments necessary. The future of EFOS technology will focus on further miniaturization, material selection appropriate for the operating pressure regime, and extensive hydrocode and optical analysis to transform apparent particle velocity time histories into true particle velocity time histories as well as the more meaningful pressure time histories.

Embedded system of image storage based on fiber channel

Science.gov (United States)

Chen, Xiaodong; Su, Wanxin; Xing, Zhongbao; Wang, Hualong

2008-03-01

In domains of aerospace, aviation, aiming, and optic measure etc., the embedded system of imaging, processing and recording is absolutely necessary, which has small volume, high processing speed and high resolution. But the embedded storage technology becomes system bottleneck because of developing slowly. It is used to use RAID to promote storage speed, but it is unsuitable for the embedded system because of its big volume. Fiber channel (FC) technology offers a new method to develop the high-speed, portable storage system. In order to make storage subsystem meet the needs of high storage rate, make use of powerful Virtex-4 FPGA and high speed fiber channel, advance a project of embedded system of digital image storage based on Xilinx Fiber Channel Arbitrated Loop LogiCORE. This project utilizes Virtex- 4 RocketIO MGT transceivers to transmit the data serially, and connects many Fiber Channel hard drivers by using of Arbitrated Loop optionally. It can achieve 400MBps storage rate, breaks through the bottleneck of PCI interface, and has excellences of high-speed, real-time, portable and massive capacity.

Analysis and experimental study on the strain transfer mechanism of an embedded basalt fiber-encapsulated fiber Bragg grating sensor

Science.gov (United States)

Zhang, Zhenglin; Wang, Yuan; Sun, Yangyang; Zhang, Qinghua; You, Zewei; Huang, Xiaodi

2017-01-01

The precision of the encapsulated fiber optic sensor embedded into a host suffers from the influences of encapsulating materials. Furthermore, an interface transfer effect of strain sensing exists. This study uses an embedded basalt fiber-encapsulated fiber Bragg grating (FBG) sensor as the research object to derive an expression in a multilayer interface strain transfer coefficient by considering the mechanical properties of the host material. The direct impact of the host material on the strain transfer at an embedded multipoint continuous FBG (i.e., multiple gratings written on a single optical fiber) monitoring strain sensor, which was self-developed and encapsulated with basalt fiber, is studied to present the strain transfer coefficients corresponding to the positions of various gratings. The strain transfer coefficients of the sensor are analyzed based on the experiments designed for this study. The error of the experimental results is ˜2 μɛ when the strain is at 60 μɛ and below. Moreover, the measured curves almost completely coincide with the theoretical curves. The changes in the internal strain field inside the embedded structure of the basalt fiber-encapsulated FBG strain sensor could be easily monitored. Hence, important references are provided to measure the internal stress strain of the sensor.

Fiber Optic Temperature Sensor Insert for High Temperature Environments

Science.gov (United States)

Black, Richard James (Inventor); Costa, Joannes M. (Inventor); Moslehi, Behzad (Inventor); Zarnescu, Livia (Inventor)

2017-01-01

A thermal protection system (TPS) test plug has optical fibers with FBGs embedded in the optical fiber arranged in a helix, an axial fiber, and a combination of the two. Optionally, one of the optical fibers is a sapphire FBG for measurement of the highest temperatures in the TPS plug. The test plug may include an ablating surface and a non-ablating surface, with an engagement surface with threads formed, the threads having a groove for placement of the optical fiber. The test plug may also include an optical connector positioned at the non-ablating surface for protection of the optical fiber during insertion and removal.

Structurally integrated fiber optic damage assessment system for composite materials.

Science.gov (United States)

Measures, R M; Glossop, N D; Lymer, J; Leblanc, M; West, J; Dubois, S; Tsaw, W; Tennyson, R C

1989-07-01

Progress toward the development of a fiber optic damage assessment system for composite materials is reported. This system, based on the fracture of embedded optical fibers, has been characterized with respect to the orientation and location of the optical fibers in the composite. Together with a special treatment, these parameters have been tailored to yield a system capable of detecting the threshold of damage for various impacted Kevlar/epoxy panels. The technique has been extended to measure the growth of a damage region which could arise from either impact, manufacturing flaws, or static overloading. The mechanism of optical fiber fracture has also been investigated. In addition, the influence of embedded optical fibers on the tensile and compressive strength of the composite material has been studied. Image enhanced backlighting has been shown to be a powerful and convenient method of assessing internal damage to translucent composite materials.

Detection of local birefringence in embedded fiber Bragg grating caused by concentrated transverse load using optical frequency domain reflectometry

Science.gov (United States)

Wada, D.; Murayama, H.; Igawa, H.

2014-05-01

We investigate the capability of local birefringence detection in an embedded fiber Bragg grating (FBG) using optical frequency domain reflectometry. We embed an FBG into carbon fiber reinforced plastic specimen, and conduct 3-point bending test. The cross-sectional stresses are applied to the FBG at the loading location in addition to the non-uniform longitudinal strain distribution over the length of the FBG. The local birefringence due to the cross-sectional stresses was successfully detected while the non-uniform longitudinal strain distribution was accurately measured.

Applications of fiber optic sensors in concrete structural health monitoring

Science.gov (United States)

Dai, Jingyun; Zhang, Wentao; Sun, Baochen; Du, Yanliang

2007-11-01

The research of fiber optic extrinsic Fabry-Perot interferometer (EFPI) sensors and their applications in concrete structural health monitoring are presented in this paper. Different types of fiber optic EFPI sensors are designed and fabricated. Experiments are carried out to test the performance of the sensors. The results show that the sensors have good linearity and stability. The applications of the fiber optic EFPI sensors in concrete structural health monitoring are also introduced. Ten fiber optic sensors are embedded into one section of the Liaohe Bridge in Qinghuangdao-Shenyang Railway. Field test demonstrates that the results of fiber optic sensors agree well with conventional strain gauges.

Localized Temperature Variations in Laser-Irradiated Composites with Embedded Fiber Bragg Grating Sensors

Directory of Open Access Journals (Sweden)

R. Brian Jenkins

2017-01-01

Full Text Available Fiber Bragg grating (FBG temperature sensors are embedded in composites to detect localized temperature gradients resulting from high energy infrared laser radiation. The goal is to detect the presence of radiation on a composite structure as rapidly as possible and to identify its location, much the same way human skin senses heat. A secondary goal is to determine how a network of sensors can be optimized to detect thermal damage in laser-irradiated composite materials or structures. Initial tests are conducted on polymer matrix composites reinforced with either carbon or glass fiber with a single optical fiber embedded into each specimen. As many as three sensors in each optical fiber measure the temporal and spatial thermal response of the composite to high energy radiation incident on the surface. Additional tests use a 2 × 2 × 3 array of 12 sensors embedded in a carbon fiber/epoxy composite to simultaneously measure temperature variations at locations on the composite surface and through the thickness. Results indicate that FBGs can be used to rapidly detect temperature gradients in a composite and their location, even for a direct strike of laser radiation on a sensor, when high temperatures can cause a non-uniform thermal response and FBG decay.

Localized Temperature Variations in Laser-Irradiated Composites with Embedded Fiber Bragg Grating Sensors.

Science.gov (United States)

Jenkins, R Brian; Joyce, Peter; Mechtel, Deborah

2017-01-27

Fiber Bragg grating (FBG) temperature sensors are embedded in composites to detect localized temperature gradients resulting from high energy infrared laser radiation. The goal is to detect the presence of radiation on a composite structure as rapidly as possible and to identify its location, much the same way human skin senses heat. A secondary goal is to determine how a network of sensors can be optimized to detect thermal damage in laser-irradiated composite materials or structures. Initial tests are conducted on polymer matrix composites reinforced with either carbon or glass fiber with a single optical fiber embedded into each specimen. As many as three sensors in each optical fiber measure the temporal and spatial thermal response of the composite to high energy radiation incident on the surface. Additional tests use a 2 × 2 × 3 array of 12 sensors embedded in a carbon fiber/epoxy composite to simultaneously measure temperature variations at locations on the composite surface and through the thickness. Results indicate that FBGs can be used to rapidly detect temperature gradients in a composite and their location, even for a direct strike of laser radiation on a sensor, when high temperatures can cause a non-uniform thermal response and FBG decay.

Fiber optic strain measurements using an optically-active polymer

Science.gov (United States)

Buckley, Leonard J.; Neumeister, Gary C.

1992-03-01

A study encompassing the use of an optically-active polymer as the strain-sensing medium in an organic matrix composite was performed. Several compounds were synthesized for use as the inner cladding material for silica fiber-optic cores. These materials include a diacetylene containing polyamide. It is possible to dynamically modify the optical properties of these materials through changes in applied strain or temperature. By doing so the characteristic absorption in the visible is reversibly shifted to a higher energy state. The polymer-coated fiber-optic cores were initially studied in epoxy resin. Additionally, one of the polyamide/diacetylene polymers was studied in a spin-fiber form consisting of 15 micron filaments assembled in multifilament tows. The most promising configuration and materials were then investigated further by embedding in graphite/epoxy composite laminates. In each case the shift in the visible absorption peak was monitored as a function of applied mechanical strain.

Design and test of a novel accelerometer made-up of an optical-fiber embedded within a polymer resin

Directory of Open Access Journals (Sweden)

Tihon Pierre

2015-01-01

Full Text Available This paper presents a transducer for an optical-fiber accelerometer based on a polarization analysis. The transducer is made up of a fiber section embedded within a resin placed between two metallic pieces. Due to the acceleration, the resin is crushed between the metallic pieces, deforming the fiber section and inducing birefringence in the latter. This birefringence modifies the light polarization state, which can be used as an acceleration measurement. The sensor characteristics (sensitivity and resonance frequency are numerically and experimentally determined. Sine accelerations at 120 Hz with amplitudes going from 5 m/s2 to 13 m/s2 have been successfully measured. The resonance frequency for the transducer crushing mode is above 5000 Hz, but low-frequency vibration modes exist, disturbing the measurements.

Crack growth monitoring in composite materials using embedded optical Fiber Bragg Grating sensor

DEFF Research Database (Denmark)

Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

2015-01-01

In this paper a novel method to assess a crack growing/damage event in fiber reinforced plastic, or adhesive using Fiber Bragg Grating (FBG) sensors embedded in a host material is shown. Different features of the crack mechanism that induce a change in the FBG response were identified. Double...

Hybrid Piezoelectric/Fiber-Optic Sensor Sheets

Science.gov (United States)

Lin, Mark; Qing, Xinlin

2004-01-01

Hybrid piezoelectric/fiber-optic (HyPFO) sensor sheets are undergoing development. They are intended for use in nondestructive evaluation and long-term monitoring of the integrity of diverse structures, including aerospace, aeronautical, automotive, and large stationary ones. It is anticipated that the further development and subsequent commercialization of the HyPFO sensor systems will lead to economic benefits in the form of increased safety, reduction of life-cycle costs through real-time structural monitoring, increased structural reliability, reduction of maintenance costs, and increased readiness for service. The concept of a HyPFO sensor sheet is a generalization of the concept of a SMART Layer(TradeMark), which is a patented device that comprises a thin dielectric film containing an embedded network of distributed piezoelectric actuator/sensors. Such a device can be mounted on the surface of a metallic structure or embedded inside a composite-material structure during fabrication of the structure. There is has been substantial interest in incorporating sensors other than piezoelectric ones into SMART Layer(TradeMark) networks: in particular, because of the popularity of the use of fiber-optic sensors for monitoring the "health" of structures in recent years, it was decided to incorporate fiber-optic sensors, giving rise to the concept of HyPFO devices.

Development of Embedded Fiber-Optic Evanescent Wave Sensors for Optical Characterization of Graphite Anodes in Lithium-Ion Batteries.

Science.gov (United States)

Ghannoum, AbdulRahman; Nieva, Patricia; Yu, Aiping; Khajepour, Amir

2017-11-29

The development, fabrication, and embedment of fiber-optic evanescent wave sensors (FOEWSs) to monitor the state of charge (SOC) and the state of health (SOH) of lithium-ion batteries (LIBs) are presented. Etching of FOEWSs is performed using a solution of 40 wt % ammonium fluoride (NH 4 F) and 49 wt % hydrofluoric acid (HF) (6:1), which is found to be superior to an etching solution containing just 49 wt % HF. FOEWSs were characterized using glycerol and found to have the highest sensitivity in a lithium-ion battery when they lose 92% of their transmittance in the presence of glycerol on their sensing region. The physical effect that the FOEWS has on the graphite anode is also investigated and is found to be much more significant in Swagelok cells compared to that in in-house-fabricated pouch cells, mainly due to pressure variation. The FOEWS was found to be most sensitive to the changes in the LIB when it was completely embedded using a slurry of graphite anode material within a pouch cell. The optimized fabrication process of the embedded FOEWS demonstrates the potential of using such sensors commercially for real-time monitoring of the SOC and SOH of LIBs while in operation.

Development and Application of Smart Geogrid Embedded with Fiber Bragg Grating Sensors

Directory of Open Access Journals (Sweden)

Zheng-fang Wang

2015-01-01

Full Text Available Smart geogrids embedded with fiber Bragg grating (FBG for reinforcement as well as measurement of geotechnical structures have been developed. After the fabricating process of the geogrids is detailed, finite element (FE simulations are conducted to analyze the strain distribution of geogrids and the strain transfer characteristics from geogrids to fiber optic. Results indicate that FBG should be deployed in the middle of the geogrids rib to make sure that uniform strain distribution along the FBG. Also, PVC protective sleeves, which are used to protect fiber optic when integrated with geogrids, have smaller strain transfer loss than nylon sleeves. Tensile experiments are conducted to test strain measurement performance of proposed geogrids, and the results demonstrate that proposed smart geogrids have good linearity and consistency. Temperature experiments show that FBG embedded in geogrids has higher temperature sensitivity, and the temperature induced error can be compensated by an extra FBG strain-independent sensor. Furthermore, designed smart geogrids are used in a geotechnical model test to monitor strain during tunnel excavation. The strain tendency measured by smart geogrids and traditional strain sensor agree very well. The results indicate that smart geogrids embedded with FBGs can be an effective method to measure strains for geological engineering related applications.

Interferometric fiber-optic sensor embedded in a spark plug for in-cylinder pressure measurement in engines.

Science.gov (United States)

Bae, Taehan; Atkins, Robert A; Taylor, Henry F; Gibler, William N

2003-02-20

Pressure sensing in an internal combustion engine with an intrinsic fiber Fabry-Perot interferometer (FFPI) integrated with a spark plug is demonstrated for the first time. The spark plug was used for the ignition of the cylinder in which it was mounted. The FFPI element, protected with a copper/gold coating, was embedded in a groove in the spark-plug housing. Gas pressure inthe engine induced longitudinal strain in this housing, which was also experienced by the fiber-optic sensing element. The sensor was monitored with a signal conditioning unit containing a chirped distributed-feedback laser. Pressure sensitivities as high as 0.00339 radians round-trip phase shift per pounds per square inch of pressure were observed. Measured pressure versus time traces showed good agreement with those from a piezoelectric reference sensor mounted in the same engine cylinder.

Vibro-Perception of Optical Bio-Inspired Fiber-Skin.

Science.gov (United States)

Li, Tao; Zhang, Sheng; Lu, Guo-Wei; Sunami, Yuta

2018-05-12

In this research, based on the principle of optical interferometry, the Mach-Zehnder and Optical Phase-locked Loop (OPLL) vibro-perception systems of bio-inspired fiber-skin are designed to mimic the tactile perception of human skin. The fiber-skin is made of the optical fiber embedded in the silicone elastomer. The optical fiber is an instinctive and alternative sensor for tactile perception with high sensitivity and reliability, also low cost and susceptibility to the magnetic interference. The silicone elastomer serves as a substrate with high flexibility and biocompatibility, and the optical fiber core serves as the vibro-perception sensor to detect physical motions like tapping and sliding. According to the experimental results, the designed optical fiber-skin demonstrates the ability to detect the physical motions like tapping and sliding in both the Mach-Zehnder and OPLL vibro-perception systems. For direct contact condition, the OPLL vibro-perception system shows better performance compared with the Mach-Zehnder vibro-perception system. However, the Mach-Zehnder vibro-perception system is preferable to the OPLL system in the indirect contact experiment. In summary, the fiber-skin is validated to have light touch character and excellent repeatability, which is highly-suitable for skin-mimic sensing.

View of the VO prototype made of two sectors of scintillating counters. WLS fibers embedded within connectors appear in green color. Beams of optical fibers inside black sheath collect and transport the emitted light to photo-multipliers a few meters apart.

CERN Multimedia

2004-01-01

View of the VO prototype made of two sectors of scintillating counters. WLS fibers embedded within connectors appear in green color. Beams of optical fibers inside black sheath collect and transport the emitted light to photo-multipliers a few meters apart.

The role of local interaction mechanics in fiber optic smart structures

Science.gov (United States)

Sirkis, J. S.; Dasgupta, A.

1993-04-01

The concept of using 'smart' composite materials/structures with built-in self-diagnostic capabilities for health monitoring involves embedding discrete and/or distributed sensory networks in the host composite material, along with a central and/or distributed artificial intelligence capability for signal processing, data collection, interpretation and diagnostic evaluations. This article concentrates on the sensory functions in 'smart' structure applications and concentrates in particular on optical fiber sensors. Specifically, we present an overview of recent research dealing with the basic mechanics of local interactions between the embedded optical fiber sensors and the surrounding host composite. The term 'local' is defined by length scales on the order of several optical fiber diameters. We examine some generic issues, such as the 'calibration' and 'obtrusivity' of the sensor, and the inherent damage caused by the sensor inclusions to the surrounding host and vice-versa under internal and/or external applied loads. Analytical, numerical and experimental results are presented regarding the influence of local strain concentrations caused by the sensory inclusions on sensor and host performance. The important issues examined are the local mechanistic effects of optical fiber coatings on the behavior of the sensor and the host, and mechanical survivability of optical fibers experiencing quasi-static and time-varying thermomechanical loading.

Laser backlight unit based on a leaky optical fiber

Science.gov (United States)

Okuda, Yuuto; Onoda, Kousuke; Fujieda, Ichiro

2012-07-01

A backlight unit is constructed by laying out an optical fiber on a two-dimensional plane and letting the light leak out in a controlled manner. In experiment, we formed multiple grooves on the surface of a plastic optical fiber by pressing a heated knife edge. The depth of the groove determined the percentage of the optical power leaking out. The optical fiber with multiple grooves was embedded in an acrylic plate with a spiral trench, and a diffuser sheet was placed over it. When we injected laser light into the end of the optical fiber, this configuration successfully worked as an area illuminator. However, the coherent nature of the laser light caused severe speckle noise. We evaluated the speckle contrast under darkness, and it varied from 80% to 23%, depending on the lens aperture used to capture the images of the illuminator. We glued an ultrasound generator to the optical fiber to introduce phase modulation for the light propagating inside the optical fiber. In this way, the speckle contrast was reduced by a factor of seven to four. Under room lighting, the speckle noise was made barely noticeable by turning on the ultrasound generator.

Embedded Distributed Optical Fiber Sensors in Reinforced Concrete Structures-A Case Study.

Science.gov (United States)

Barrias, António; Casas, Joan R; Villalba, Sergi

2018-03-26

When using distributed optical fiber sensors (DOFS) on reinforced concrete structures, a compromise must be achieved between the protection requirements and robustness of the sensor deployment and the accuracy of the measurements both in the uncracked and cracked stages and under loading, unloading and reloading processes. With this in mind the authors have carried out an experiment where polyimide-coated DOFS were installed on two concrete beams, both embedded in the rebar elements and also bonded to the concrete surface. The specimens were subjected to a three-point load test where after cracking, they are unloaded and reloaded again to assess the capability of the sensor when applied to a real loading scenarios in concrete structures. Rayleigh Optical Frequency Domain Reflectometry (OFDR) was used as the most suitable technique for crack detection in reinforced concrete elements. To verify the reliability and accuracy of the DOFS measurements, additional strain gauges were also installed at three locations along the rebar. The results show the feasibility of using a thin coated polyimide DOFS directly bonded on the reinforcing bar without the need of indention or mechanization. A proposal for a Spectral Shift Quality (SSQ) threshold is also obtained and proposed for future works when using polyimide-coated DOFS bonded to rebars with cyanoacrylate adhesive.

Embedded Distributed Optical Fiber Sensors in Reinforced Concrete Structures—A Case Study

Science.gov (United States)

Villalba, Sergi

2018-01-01

When using distributed optical fiber sensors (DOFS) on reinforced concrete structures, a compromise must be achieved between the protection requirements and robustness of the sensor deployment and the accuracy of the measurements both in the uncracked and cracked stages and under loading, unloading and reloading processes. With this in mind the authors have carried out an experiment where polyimide-coated DOFS were installed on two concrete beams, both embedded in the rebar elements and also bonded to the concrete surface. The specimens were subjected to a three-point load test where after cracking, they are unloaded and reloaded again to assess the capability of the sensor when applied to a real loading scenarios in concrete structures. Rayleigh Optical Frequency Domain Reflectometry (OFDR) was used as the most suitable technique for crack detection in reinforced concrete elements. To verify the reliability and accuracy of the DOFS measurements, additional strain gauges were also installed at three locations along the rebar. The results show the feasibility of using a thin coated polyimide DOFS directly bonded on the reinforcing bar without the need of indention or mechanization. A proposal for a Spectral Shift Quality (SSQ) threshold is also obtained and proposed for future works when using polyimide-coated DOFS bonded to rebars with cyanoacrylate adhesive. PMID:29587449

Fiber optic and laser sensors IV; Proceedings of the Meeting, Cambridge, MA, Sept. 22-24, 1986

Science.gov (United States)

De Paula, Ramon P. (Editor); Udd, Eric (Editor)

1987-01-01

The conference presents papers on industrial uses of fiber optic sensors, point and distributed polarimetric optical fiber sensors, fiber optic electric field sensor technology, micromachined resonant structures, single-mode fibers for sensing applications, and measurement techniques for magnetic field gradient detection. Consideration is also given to electric field meter and temperature measurement techniques for the power industry, the calibration of high-temperature fiber-optic microbend pressure transducers, and interferometric sensors for dc measurands. Other topics include the recognition of colors and collision avoidance in robotics using optical fiber sensors, the loss compensation of intensity-modulating fiber-optic sensors, and an embedded optical fiber strain tensor for composite structure applications.

Demonstration and Methodology of Structural Monitoring of Stringer Runs out Composite Areas by Embedded Optical Fiber Sensors and Connectors Integrated during Production in a Composite Plant.

Science.gov (United States)

Miguel Giraldo, Carlos; Zúñiga Sagredo, Juan; Sánchez Gómez, José; Corredera, Pedro

2017-07-21

Embedding optical fibers sensors into composite structures for Structural Health Monitoring purposes is not just one of the most attractive solutions contributing to smart structures, but also the optimum integration approach that insures maximum protection and integrity of the fibers. Nevertheless this intended integration level still remains an industrial challenge since today there is no mature integration process in composite plants matching all necessary requirements. This article describes the process developed to integrate optical fiber sensors in the Production cycle of a test specimen. The sensors, Bragg gratings, were integrated into the laminate during automatic tape lay-up and also by a secondary bonding process, both in the Airbus Composite Plant. The test specimen, completely representative of the root joint of the lower wing cover of a real aircraft, is comprised of a structural skin panel with the associated stringer run out. The ingress-egress was achieved through the precise design and integration of miniaturized optical connectors compatible with the manufacturing conditions and operational test requirements. After production, the specimen was trimmed, assembled and bolted to metallic plates to represent the real triform and buttstrap, and eventually installed into the structural test rig. The interrogation of the sensors proves the effectiveness of the integration process; the analysis of the strain results demonstrate the good correlation between fiber sensors and electrical gauges in those locations where they are installed nearby, and the curvature and load transfer analysis in the bolted stringer run out area enable demonstration of the consistency of the fiber sensors measurements. In conclusion, this work presents strong evidence of the performance of embedded optical sensors for structural health monitoring purposes, where in addition and most importantly, the fibers were integrated in a real production environment and the ingress

Fiber-optic multipoint radiation sensing system using waveguide scintillators

International Nuclear Information System (INIS)

Maekawa, Tatsuyuki; Yoda, Masaki; Tanaka, Koutarou; Masumaru, Tarou; Morimoto, Souichirou.

1996-01-01

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

Clad modified optical fiber gas sensors based on nanocrystalline nickel oxide embedded coatings

Science.gov (United States)

Yamini, K.; Renganathan, B.; Ganesan, A. R.; Prakash, T.

2017-07-01

A clad modified optical fiber gas sensor for sensing volatile organic compound vapours (VOCs) such as formaldehyde (HCHO), ammonia (NH3), ethanol (C2H5OH) and methanol (CH3OH) up to 500 ppm was studied using nanocrystalline nickel oxide embedded coatings. Prior to the measurements, nickel oxide in two different crystallite sizes such as 24 nm and 76 nm was synthesized by calcination of reverse precipitated nickel hydroxide subsequently at 450 °C and 900 °C for 30 min. Then, samples physical properties were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). Our gas sensing measurement concludes that the lower crystallite size (24 nm) nickel oxide nanocrystals exhibits superior performance to formaldehyde and ethanol vapours as compared with other two VOCs, the observed experimental results were discussed in detail.

Study of distributed fiber-optic laser-ultrasound generation based on ghost-mode of tilted fiber Bragg gratings

Science.gov (United States)

Tian, Jiajun; Zhang, Qi; Han, Ming

2013-05-01

Fiber-optic ultrasonic transducers are an important component of an active ultrasonic testing system for structural health monitoring. Fiber-optic transducers have several advantages such as small size, light weight, and immunity to electromagnetic interference that make them much more attractive than the current available piezoelectric transducers, especially as embedded and permanent transducers in active ultrasonic testing for structural health monitoring. In this paper, a distributed fiber-optic laser-ultrasound generation based on the ghost-mode of tilted fiber Bragg gratings is studied. The influences of the laser power and laser pulse duration on the laser-ultrasound generation are investigated. The results of this paper are helpful to understand the working principle of this laser-ultrasound method and improve the ultrasonic generation efficiency.

Strain monitoring of cement-based materials with embedded polyvinyl alcohol - carbon nanotube (PVA-CNT fibers

Directory of Open Access Journals (Sweden)

Zoi S. Metaxa

2017-04-01

Full Text Available This article investigates the possibility of exploiting innovative polyvinyl alcohol fibers reinforced with carbon nanotubes (PVA-CNT fiber as a strain sensor in cement mortars used in the restoration of Cultural Heritage Monuments. Two types of PVA-CNT fibers were embedded in the matrix at a short distance from the bottom of the beam and their readings were correlated with traditional sensors, e.g. strain gauges and Fiber Optic Bragg Gratings. The Electrical Resistance Change (ERC of the embedded PVA-CNT fiber was in-situ monitored during four-point bending mechanical tests. For the case of coated PVA-CNT fiber, a linear correlation of the applied strain at the bottom surface of the specimen along with ERC values of the fiber was noticed for the low strain regime. For the case of incremental increasing loading – unloading loops, the coated and annealed PVA-CNT fiber gave the best results either as embedded or as ‘surface attached’ sensor that exhibited linear correlation of ERC with applied strain for the low applied strain regime as well as hysteresis loops during unloading. The article discusses their high potential to be exploited as strain/damage sensor in applications of civil engineering as well as in restoration of Monuments of Cultural Heritage.

Water-equivalent one-dimensional scintillating fiber-optic dosimeter for measuring therapeutic photon beam

International Nuclear Information System (INIS)

Moon, Jinsoo; Won Jang, Kyoung; Jae Yoo, Wook; Han, Ki-Tek; Park, Jang-Yeon; Lee, Bongsoo

2012-01-01

In this study, we fabricated a one-dimensional scintillating fiber-optic dosimeter, which consists of 9 scintillating fiber-optic dosimeters, septa, and PMMA blocks for measuring surface and percentage depth doses of a therapeutic photon beam. Each dosimeter embedded in the 1-D scintillating fiber-optic dosimeter is composed of square type organic scintillators and plastic optical fibers. Also black PVC films are used as septa to minimize cross-talk between the scintillating fiber-optic dosimeters. To construct a dosimeter system, a 1-D scintillating fiber-optic dosimeter and a CMOS image sensor were combined with 20 m-length plastic optical fibers. Using the dosimeter system, we measured surface and percentage depth doses of 6 and 15 MV photon beams and compared the results with those of EBT films and an ionization chamber. - Highlights: ► Fabrication of a one-dimensional scintillating fiber-optic dosimeter. ► The one-dimensional scintillating fiber-optic dosimeter has 9 scintillating fiber-optic dosimeters. ► Measurements of surface and percentage depth doses of a therapeutic photon beam. ► The results were compared with those of EBT films and an ionization chamber.

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

Science.gov (United States)

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

2015-02-14

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

Fiber optic connector

Science.gov (United States)

Rajic, Slobodan; Muhs, Jeffrey D.

1996-01-01

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

Dynamic virtual optical network embedding in spectral and spatial domains over elastic optical networks with multicore fibers

Science.gov (United States)

Zhu, Ruijie; Zhao, Yongli; Yang, Hui; Tan, Yuanlong; Chen, Haoran; Zhang, Jie; Jue, Jason P.

2016-08-01

Network virtualization can eradicate the ossification of the infrastructure and stimulate innovation of new network architectures and applications. Elastic optical networks (EONs) are ideal substrate networks for provisioning flexible virtual optical network (VON) services. However, as network traffic continues to increase exponentially, the capacity of EONs will reach the physical limitation soon. To further increase network flexibility and capacity, the concept of EONs is extended into the spatial domain. How to map the VON onto substrate networks by thoroughly using the spectral and spatial resources is extremely important. This process is called VON embedding (VONE).Considering the two kinds of resources at the same time during the embedding process, we propose two VONE algorithms, the adjacent link embedding algorithm (ALEA) and the remote link embedding algorithm (RLEA). First, we introduce a model to solve the VONE problem. Then we design the embedding ability measurement of network elements. Based on the network elements' embedding ability, two VONE algorithms were proposed. Simulation results show that the proposed VONE algorithms could achieve better performance than the baseline algorithm in terms of blocking probability and revenue-to-cost ratio.

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

Science.gov (United States)

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

2009-03-01

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

Improving the durability of the optical fiber sensor based on strain transfer analysis

Science.gov (United States)

Wang, Huaping; Jiang, Lizhong; Xiang, Ping

2018-05-01

To realize the reliable and long-term strain detection, the durability of optical fiber sensors has attracted more and more attention. The packaging technique has been considered as an effective method, which can enhance the survival ratios of optical fiber sensors to resist the harsh construction and service environment in civil engineering. To monitor the internal strain of structures, the embedded installation is adopted. Due to the different material properties between host material and the protective layer, the monitored structure embedded with sensors can be regarded as a typical model containing inclusions. Interfacial characteristic between the sensor and host material exists obviously, and the contacted interface is prone to debonding failure induced by the large interfacial shear stress. To recognize the local interfacial debonding damage and extend the effective life cycle of the embedded sensor, strain transfer analysis of a general three-layered sensing model is conducted to investigate the failure mechanism. The perturbation of the embedded sensor on the local strain field of host material is discussed. Based on the theoretical analysis, the distribution of the interfacial shear stress along the sensing length is characterized and adopted for the diagnosis of local interfacial debonding, and the sensitive parameters influencing the interfacial shear stress are also investigated. The research in this paper explores the interfacial debonding failure mechanism of embedded sensors based on the strain transfer analysis and provides theoretical basis for enhancing the interfacial bonding properties and improving the durability of embedded optical fiber sensors.

Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

International Nuclear Information System (INIS)

Wang, Huaping; Xiang, Ping

2016-01-01

Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks. (paper)

Strain transfer analysis of optical fiber based sensors embedded in an asphalt pavement structure

Science.gov (United States)

Wang, Huaping; Xiang, Ping

2016-07-01

Asphalt pavement is vulnerable to random damage, such as cracking and rutting, which can be proactively identified by distributed optical fiber sensing technology. However, due to the material nature of optical fibers, a bare fiber is apt to be damaged during the construction process of pavements. Thus, a protective layer is needed for this application. Unfortunately, part of the strain of the host material is absorbed by the protective layer when transferring the strain to the sensing fiber. To account for the strain transfer error, in this paper a theoretical analysis of the strain transfer of a three-layered general model has been carried out by introducing Goodman’s hypothesis to describe the interfacial shear stress relationship. The model considers the viscoelastic behavior of the host material and protective layer. The effects of one crack in the host material and the sensing length on strain transfer relationship are been discussed. To validate the effectiveness of the strain transfer analysis, a flexible asphalt-mastic packaged distributed optical fiber sensor was designed and tested in a laboratory environment to monitor the distributed strain and appearance of cracks in an asphalt concrete beam at two different temperatures. The experimental results indicated that the developed strain transfer formula can significantly reduce the strain transfer error, and that the asphalt-mastic packaged optical fiber sensor can successfully monitor the distributed strain and identify local cracks.

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

International Nuclear Information System (INIS)

Lu, Y; Shi, B; Wei, G Q; Zhang, D; Chen, S E

2012-01-01

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

Highly fluorescent silver nanoclusters in alumina-silica composite optical fiber

Energy Technology Data Exchange (ETDEWEB)

Halder, A.; Chattopadhyay, R.; Majumder, S.; Paul, M. C.; Das, S.; Bhadra, S. K., E-mail: skbhadra@cgcri.res.in [Fiber Optics and Photonics Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata 700032 (India); Bysakh, S.; Unnikrishnan, M. [Material Characterization Division, CSIR-Central Glass and Ceramic Research Institute, 196, Raja S. C. Mullick Road, Kolkata 700032 (India)

2015-01-05

An efficient visible fluorescent optical fiber embedded with silver nanoclusters (Ag-NCs) having size ∼1 nm, uniformly distributed in alumina-silica composite core glass, is reported. Fibers are fabricated in a repetitive controlled way through modified chemical vapour deposition process associated with solution doping technique. Fibers are drawn from the transparent preforms by conventional fiber drawing process. Structural characteristics of the doped fibers are studied using transmission electron microscopy and electron probe micro analysis. The oxidation state of Ag within Ag-NCs is investigated by X-ray photo electron spectroscopy. The observed significant fluorescence of the metal clusters in fabricated fibers is correlated with electronic model. The experimentally observed size dependent absorption of the metal clusters in fabricated fibers is explained with the help of reported results calculated by ab-initio density functional theory. These optical fibers may open up an opportunity of realizing tunable wavelength fiber laser without the help of rare earth elements.

Structural health monitoring of civil infrastructure using optical fiber sensing technology: a comprehensive review.

Science.gov (United States)

Ye, X W; Su, Y H; Han, J P

2014-01-01

In the last two decades, a significant number of innovative sensing systems based on optical fiber sensors have been exploited in the engineering community due to their inherent distinctive advantages such as small size, light weight, immunity to electromagnetic interference (EMI) and corrosion, and embedding capability. A lot of optical fiber sensor-based monitoring systems have been developed for continuous measurement and real-time assessment of diversified engineering structures such as bridges, buildings, tunnels, pipelines, wind turbines, railway infrastructure, and geotechnical structures. The purpose of this review article is devoted to presenting a summary of the basic principles of various optical fiber sensors, innovation in sensing and computational methodologies, development of novel optical fiber sensors, and the practical application status of the optical fiber sensing technology in structural health monitoring (SHM) of civil infrastructure.

Fiber optics in adverse environments

International Nuclear Information System (INIS)

Lyous, P.B.

1982-01-01

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

Testing of a Fiber Optic Wear, Erosion and Regression Sensor

Science.gov (United States)

Korman, Valentin; Polzin, Kurt A.

2011-01-01

The nature of the physical processes and harsh environments associated with erosion and wear in propulsion environments makes their measurement and real-time rate quantification difficult. A fiber optic sensor capable of determining the wear (regression, erosion, ablation) associated with these environments has been developed and tested in a number of different applications to validate the technique. The sensor consists of two fiber optics that have differing attenuation coefficients and transmit light to detectors. The ratio of the two measured intensities can be correlated to the lengths of the fiber optic lines, and if the fibers and the host parent material in which they are embedded wear at the same rate the remaining length of fiber provides a real-time measure of the wear process. Testing in several disparate situations has been performed, with the data exhibiting excellent qualitative agreement with the theoretical description of the process and when a separate calibrated regression measurement is available good quantitative agreement is obtained as well. The light collected by the fibers can also be used to optically obtain the spectra and measure the internal temperature of the wear layer.

Fiber-optical accelerometers based on polymer optical fiber Bragg gratings

DEFF Research Database (Denmark)

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

2010-01-01

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

Fiber optic corrosion sensing for bridges and roadway surfaces

Science.gov (United States)

Fuhr, Peter L.; Ambrose, Timothy P.; Huston, Dryver R.; McPadden, Adam P.

1995-04-01

In this paper we report the development of a fiber optic corrosion sensing system that complements and/or surpasses the capabilities of conventional corrosion sensing techniques. The sensing system is based on evanescent wave phenomena and in the configured sensor allows for the detection of general corrosion on and within materials. Based on the authors' experience installing may kilometers of fiberoptic sensors into large civil structures such as multistory buildings, hydroelectric dams, and railway/roadway bridges, we are (currently) embedding these sensors into bridge test members -- limited structures that are being subjected to accelerated corrosion testing conditions. Three Vermont Agency of Transportation bridges, one in a low salt use region, one in a medium salt use region, and the third in a high salt use region, are being selected and will be instrumented with these embedded fiber optic corrosion sensors. Monitoring of chloride penetration and rebar corrosion status will be measured during the course of a longitudinal study. The specific sensing mechanism and design for robustness (to allow survival of the embedding process during repaving of the bridges) are discussed and laboratory and initial field results are presented.

Excitation of epsilon-near-zero resonance in ultra-thin indium tin oxide shell embedded nanostructured optical fiber.

Science.gov (United States)

Minn, Khant; Anopchenko, Aleksei; Yang, Jingyi; Lee, Ho Wai Howard

2018-02-05

We report a novel optical waveguide design of a hollow step index fiber modified with a thin layer of indium tin oxide (ITO). We show an excitation of highly confined waveguide mode in the proposed fiber near the wavelength where permittivity of ITO approaches zero. Due to the high field confinement within thin ITO shell inside the fiber, the epsilon-near-zero (ENZ) mode can be characterized by a peak in modal loss of the hybrid waveguide. Our results show that such in-fiber excitation of ENZ mode is due to the coupling of the guided core mode to the thin-film ENZ mode. We also show that the phase matching wavelength, where the coupling takes place, varies depending on the refractive index of the constituents inside the central bore of the fiber. These ENZ nanostructured optical fibers have many potential applications, for example, in ENZ nonlinear and magneto-optics, as in-fiber wavelength-dependent filters, and as subwavelength fluid channel for optical and bio-photonic sensing.

Structural Health Monitoring of Civil Infrastructure Using Optical Fiber Sensing Technology: A Comprehensive Review

Science.gov (United States)

Ye, X. W.; Su, Y. H.; Han, J. P.

2014-01-01

In the last two decades, a significant number of innovative sensing systems based on optical fiber sensors have been exploited in the engineering community due to their inherent distinctive advantages such as small size, light weight, immunity to electromagnetic interference (EMI) and corrosion, and embedding capability. A lot of optical fiber sensor-based monitoring systems have been developed for continuous measurement and real-time assessment of diversified engineering structures such as bridges, buildings, tunnels, pipelines, wind turbines, railway infrastructure, and geotechnical structures. The purpose of this review article is devoted to presenting a summary of the basic principles of various optical fiber sensors, innovation in sensing and computational methodologies, development of novel optical fiber sensors, and the practical application status of the optical fiber sensing technology in structural health monitoring (SHM) of civil infrastructure. PMID:25133250

Structural Health Monitoring of Civil Infrastructure Using Optical Fiber Sensing Technology: A Comprehensive Review

Directory of Open Access Journals (Sweden)

X. W. Ye

2014-01-01

Full Text Available In the last two decades, a significant number of innovative sensing systems based on optical fiber sensors have been exploited in the engineering community due to their inherent distinctive advantages such as small size, light weight, immunity to electromagnetic interference (EMI and corrosion, and embedding capability. A lot of optical fiber sensor-based monitoring systems have been developed for continuous measurement and real-time assessment of diversified engineering structures such as bridges, buildings, tunnels, pipelines, wind turbines, railway infrastructure, and geotechnical structures. The purpose of this review article is devoted to presenting a summary of the basic principles of various optical fiber sensors, innovation in sensing and computational methodologies, development of novel optical fiber sensors, and the practical application status of the optical fiber sensing technology in structural health monitoring (SHM of civil infrastructure.

Fiber-optic triggered release of liposome in vivo: implication of personalized chemotherapy.

Science.gov (United States)

Huang, Huei-Ling; Lu, Pei-Hsuan; Yang, Hung-Chih; Lee, Gi-Da; Li, Han-Ru; Liao, Kuo-Chih

2015-01-01

The aim of this research is to provide proof of principle by applying the fiber-optic triggered release of photo-thermally responsive liposomes embedded with gold nanoparticles (AuNPs) using a 200 μm fiber with 65 mW and 532 nm excitation for topical release in vivo. The tunable delivery function can be paired with an apoptosis biosensor based on the same fiber-optic configuration for providing real-time evaluation of chemotherapy efficacy in vivo to perform as a personalized chemotherapy system. The pattern of topical release triggered by laser excitation conveyed through optical fibers was monitored by the increase in fluorescence resulting from the dilution of self-quenching (75 mM) fluorescein encapsulated in liposomes. In in vitro studies (in 37°C phosphate buffer saline), the AuNP-embedded liposomes showed a more efficient triggered release (74.53%±1.63% in 40 minutes) than traditional temperature-responsive liposomes without AuNPs (14.53%±3.17%) or AuNP-liposomes without excitation (21.92%±2.08%) by spectroscopic measurements. Using the mouse xenograft studies, we first demonstrated that the encapsulation of fluorescein in liposomes resulted in a more substantial content retention (81%) in the tumor than for free fluorophores (14%) at 120 minutes after administration from in vivo fluorescence imaging. Furthermore, the preliminary results also suggested the tunable release capability of the system by demonstrating consecutive triggered releases with fiber-optic guided laser excitation.

Strain measurement in a concrete beam by use of the Brillouin-scattering-based distributed fiber sensor with single-mode fibers embedded in glass fiber reinforced polymer rods and bonded to steel reinforcing bars.

Science.gov (United States)

Zeng, Xiaodong; Bao, Xiaoyi; Chhoa, Chia Yee; Bremner, Theodore W; Brown, Anthony W; DeMerchant, Michael D; Ferrier, Graham; Kalamkarov, Alexander L; Georgiades, Anastasis V

2002-08-20

The strain measurement of a 1.65-m reinforced concrete beam by use of a distributed fiber strain sensor with a 50-cm spatial resolution and 5-cm readout resolution is reported. The strain-measurement accuracy is +/-15 microepsilon (microm/m) according to the system calibration in the laboratory environment with non-uniform-distributed strain and +/-5 microepsilon with uniform strain distribution. The strain distribution has been measured for one-point and two-point loading patterns for optical fibers embedded in pultruded glass fiber reinforced polymer (GFRP) rods and those bonded to steel reinforcing bars. In the one-point loading case, the strain deviations are +/-7 and +/-15 microepsilon for fibers embedded in the GFRP rods and fibers bonded to steel reinforcing bars, respectively, whereas the strain deviation is +/-20 microepsilon for the two-point loading case.

[New type distributed optical fiber temperature sensor (DTS) based on Raman scattering and its' application].

Science.gov (United States)

Wang, Jian-Feng; Liu, Hong-Lin; Zhang, Shu-Qin; Yu, Xiang-Dong; Sun, Zhong-Zhou; Jin, Shang-Zhong; Zhang, Zai-Xuan

2013-04-01

Basic principles, development trends and applications status of distributed optical fiber Raman temperature sensor (DTS) are introduced. Performance parameters of DTS system include the sensing optical fiber length, temperature measurement uncertainty, spatial resolution and measurement time. These parameters have a certain correlation and it is difficult to improve them at the same time by single technology. So a variety of key techniques such as Raman amplification, pulse coding technique, Raman related dual-wavelength self-correction technique and embedding optical switching technique are researched to improve the performance of the DTS system. A 1 467 nm continuous laser is used as pump laser and the light source of DTS system (1 550 nm pulse laser) is amplified. When the length of sensing optical fiber is 50 km the Raman gain is about 17 dB. Raman gain can partially compensate the transmission loss of optical fiber, so that the sensing length can reach 50 km. In DTS system using pulse coding technique, pulse laser is coded by 211 bits loop encoder and correlation calculation is used to demodulate temperature. The encoded laser signal is related, whereas the noise is not relevant. So that signal-to-noise ratio (SNR) of DTS system can be improved significantly. The experiments are carried out in DTS system with single mode optical fiber and multimode optical fiber respectively. Temperature measurement uncertainty can all reach 1 degrees C. In DTS system using Raman related dual-wavelength self-correction technique, the wavelength difference of the two light sources must be one Raman frequency shift in optical fiber. For example, wavelength of the main laser is 1 550 nm and wavelength of the second laser must be 1 450 nm. Spatial resolution of DTS system is improved to 2 m by using dual-wavelength self-correction technique. Optical switch is embedded in DTS system, so that the temperature measurement channel multiply extended and the total length of the sensing

Growth, structure, and optical properties of carbon-reinforced silica fibers

International Nuclear Information System (INIS)

Zhang, Z. J.; Ajayan, P. M.; Ramanath, G.; Vacik, J.; Xu, Y. H.

2001-01-01

We report the synthesis of carbon-reinforced silica fibers by methane exposure of metallocene-treated oxidized-Si(001) substrates at 1100 degree C. The SiO 2 cap layer transforms into silica fibers reinforced by glassy carbon in the core during methane exposure. High-resolution electron microscopy and spatially resolved spectroscopy measurements of the fibers reveal an amorphous structure without a hollow, and domains of glassy carbon embedded at the fiber core. The carbon-reinforced fibers are optically transparent and have an optical band gap of ≅3.1 eV. These fibers are organized in radial patterns that vary for different metallocene species. On nickelocene-treated substrates, the fibers originate from the circumference of the circular templates and grow outwards, forming radial patterns. On ferrocene-treated substrates, randomly oriented fibers grow within as well as slightly outside the perimeter of the templates, forming wreath-like patterns. Aligned growth of such fibers could be useful for fabricating optoelectronics devices and reinforced composites. [copyright] 2001 American Institute of Physics

Two Fiber Optical Fiber Thermometry

Science.gov (United States)

Jones, Mathew R.; Farmer, Jeffery T.; Breeding, Shawn P.

2000-01-01

An optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber is essentially an isothermal cavity, so the emission from this cavity will be approximately equal to the emission from a blackbody. Temperature readings are obtained by measuring the spectral radiative heat flux at the end of the fiber at two wavelengths. The ratio of these measurements and Planck's Law are used to infer the temperature at the sensing tip. Optical fiber thermometers have high accuracy, excellent long-term stability and are immune to electromagnetic interference. In addition, they can be operated for extended periods without requiring re-calibration. For these reasons. it is desirable to use optical fiber thermometers in environments such as the International Space Station. However, it has recently been shown that temperature readings are corrupted by emission from the fiber when extended portions of the probe are exposed to elevated temperatures. This paper will describe several ways in which the reading from a second fiber can be used to correct the corrupted temperature measurements. The accuracy and sensitivity to measurement uncertainty will be presented for each method.

Fiber Optic Microphone

Science.gov (United States)

Cho, Y. C.; George, Thomas; Norvig, Peter (Technical Monitor)

1999-01-01

Research into advanced pressure sensors using fiber-optic technology is aimed at developing compact size microphones. Fiber optic sensors are inherently immune to electromagnetic noise, and are very sensitive, light weight, and highly flexible. In FY 98, NASA researchers successfully designed and assembled a prototype fiber-optic microphone. The sensing technique employed was fiber optic Fabry-Perot interferometry. The sensing head is composed of an optical fiber terminated in a miniature ferrule with a thin, silicon-microfabricated diaphragm mounted on it. The optical fiber is a single mode fiber with a core diameter of 8 micron, with the cleaved end positioned 50 micron from the diaphragm surface. The diaphragm is made up of a 0.2 micron thick silicon nitride membrane whose inner surface is metallized with layers of 30 nm titanium, 30 nm platinum, and 0.2 micron gold for efficient reflection. The active sensing area is approximately 1.5 mm in diameter. The measured differential pressure tolerance of this diaphragm is more than 1 bar, yielding a dynamic range of more than 100 dB.

Optical Communication over Plastic Optical Fibers Integrated Optical Receiver Technology

CERN Document Server

Atef, Mohamed

2013-01-01

This book presents high-performance data transmission over plastic optical fibers (POF) using integrated optical receivers having good properties with multilevel modulation, i.e. a higher sensitivity and higher data rate transmission over a longer plastic optical fiber length. Integrated optical receivers and transmitters with high linearity are introduced for multilevel communication. For binary high-data rate transmission over plastic optical fibers, an innovative receiver containing an equalizer is described leading also to a high performance of a plastic optical fiber link. The cheap standard PMMA SI-POF (step-index plastic optical fiber) has the lowest bandwidth and the highest attenuation among multimode fibers. This small bandwidth limits the maximum data rate which can be transmitted through plastic optical fibers. To overcome the problem of the plastic optical fibers high transmission loss, very sensitive receivers must be used to increase the transmitted length over POF. The plastic optical fiber li...

Fiber Singular Optics

OpenAIRE

A. V. Volyar

2002-01-01

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

Fiber-optic triggered release of liposome in vivo: implication of personalized chemotherapy

Directory of Open Access Journals (Sweden)

Huang HL

2015-08-01

Full Text Available Huei-Ling Huang,1 Pei-Hsuan Lu,1 Hung-Chih Yang,1 Gi-Da Lee,1,2 Han-Ru Li,1 Kuo-Chih Liao1 1Graduate Institute of Biomedical Engineering, National Chung Hsing University, 2Department of Radiology, Taichung Veterans General Hospital, Taichung, Taiwan Abstract: The aim of this research is to provide proof of principle by applying the fiber-optic triggered release of photo-thermally responsive liposomes embedded with gold nanoparticles (AuNPs using a 200 µm fiber with 65 mW and 532 nm excitation for topical release in vivo. The tunable delivery function can be paired with an apoptosis biosensor based on the same fiber-optic configuration for providing real-time evaluation of chemotherapy efficacy in vivo to perform as a personalized chemotherapy system. The pattern of topical release triggered by laser excitation conveyed through optical fibers was monitored by the increase in fluorescence resulting from the dilution of self-quenching (75 mM fluorescein encapsulated in liposomes. In in vitro studies (in 37°C phosphate buffer saline, the AuNP-embedded liposomes showed a more efficient triggered release (74.53%±1.63% in 40 minutes than traditional temperature-responsive liposomes without AuNPs (14.53%±3.17% or AuNP-liposomes without excitation (21.92%±2.08% by spectroscopic measurements. Using the mouse xenograft studies, we first demonstrated that the encapsulation of fluorescein in liposomes resulted in a more substantial content retention (81% in the tumor than for free fluorophores (14% at 120 minutes after administration from in vivo fluorescence imaging. Furthermore, the preliminary results also suggested the tunable release capability of the system by demonstrating consecutive triggered releases with fiber-optic guided laser excitation. Keywords: fiber-optic guided excitation, light excitation triggered release, photo-thermal responsive liposome, gold nanoparticles, tunable release in vivo

The usage of optical fibers for damage detection in ballistic protection composite laminates

Directory of Open Access Journals (Sweden)

Živković Irena D.

2006-01-01

Full Text Available This paper describes the procedure of embedding fiber optic sensors in laminar thermoplastic composite material, as well as damage investigation after ballistic loading. Thermoplastic-reinforced composite materials were made for increased material damage resistance during ballistic loading. Damage inside the composite material was detected by observing the intensity drop of the light signal transmitted through the optical fibers. Experimental testing was carried out in order to observe and analyze the response of the material under various load conditions. Different types of Kevlar reinforced composite materials (thermoplastic, thermo reactive and thermoplastic with ceramic plate as the impact face were made. Material damage resistance during ballistic loading was investigated and compared. Specimens were tested under multiple load conditions. The opto-electronic part of the measurement system consists of two light-emitting diodes as light sources for the optical fibers, and two photo detectors for the light intensity measurement. The output signal was acquired from photo detectors by means of a data acquisition board and personal computer. The measurements showed an intensity drop of the transmitted light signal as a result of the applied loading on composite structure for all the optical fibers. All the diagrams show similar behavior of the light signal intensity. In fact, all of them may be divided into three zones: the zone of penetration of the first composite layer, the bullet traveling zone through the composite material till its final stop, and the material relaxation zone. The attenuation of the light signal intensity during impact is caused by the influence of the applied dynamic stress on the embedded optical fibers. The applied stress caused micro bending of the optical fiber, changes in the shape of the cross-section and the unequal changes of the indices of refraction of the core and cladding due to the stress-optic effect. The

Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

Science.gov (United States)

Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

2015-01-01

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

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

Science.gov (United States)

Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

2015-09-30

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

Control systems using modal domain optical fiber sensors for smart structure applications

Science.gov (United States)

Lindner, Douglas K.; Reichard, Karl M.

1991-01-01

Recently, a new class of sensors has emerged for structural control which respond to environmental changes over a significant gauge length; these sensors are called distributed-effect sensors. These sensors can be fabricated with spatially varying sensitivity to the distributed measurand, and can be configured to measure a variety of structural parameters which can not be measured directly using point sensors. Examples of distributed-effect sensors include piezoelectric film, holographic sensors, and modal domain optical fiber sensors. Optical fiber sensors are particularly attractive for smart structure applications because they are flexible, have low mass, and can easily be embedded directly into materials. In this paper we describe the implementation of weighted modal domain optical fiber sensors. The mathematical model of the modal domain optical fiber sensor model is described and used to derive an expression for the sensor sensitivity. The effects of parameter variations on the sensor sensitivity are demonstrated to illustrate methods of spatially varying the sensor sensitivity.

Application Specific Optical Fibers

OpenAIRE

Pal, Bishnu P.

2010-01-01

In this chapter we have attempted to provide a unified summary description of the most important propagation characteristics of an optical fiber followed by discussion on several variety of special fibers for realizing fiber amplifiers, dispersion compensating fibers, microstructured optical fibers, and so on. Even though huge progress has been made on development of optical fibers for telecom application, a need for developing special fibers, not necessarily for telecom alone, has arisen. Th...

Relative humidity sensor based on surface plasmon resonance of D-shaped fiber with polyvinyl alcohol embedding Au grating

Science.gov (United States)

Yan, Haitao; Han, Daofu; Li, Ming; Lin, Bo

2017-01-01

This paper presents the design, fabrication, and characterization of a D-shaped fiber coated with polyvinyl alcohol (PVA) embedding an Au grating-based relative humidity (RH) sensor. The Au grating is fabricated on a D-shaped fiber to match the wave-vector and excite the surface plasmon, and the PVA is embedded in the Au grating as a sensitive cladding film. The refractive index of PVA changes with the ambient humidity. Measurements in a controlled environment show that the RH sensor can achieve a sensitivity of 5.4 nm per relative humidity unit in the RH range from 0% to 70% RH. Moreover, the surface plasmon resonance can be realized and used for RH sensing at the C band of optical fiber communication instead of the visible light band due to the metallic grating microstructure on the D-shaped fiber.

Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

Directory of Open Access Journals (Sweden)

Marie Pospíšilová

2015-09-01

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

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

Directory of Open Access Journals (Sweden)

Marioli-Riga Z.

2010-06-01

Full Text Available Polyvinyl alcohol - carbon nanotube (PVA-CNT fibers had been embedded to glass fiber reinforced polymers (GFRP for the structural health monitoring of the composite material. The addition of the conductive PVA-CNT fiber to the nonconductive GFRP material aimed to enhance its sensing ability by means of the electrical resistance measurement method. The test specimen’s response to mechanical load and the in situ PVA-CNT fiber’s electrical resistance measurements were correlated for sensing and damage monitoring purposes. The embedded PVA-CNT fiber worked as a sensor in GFRP coupons in tensile loadings. Sensing ability of the PVA-CNT fibers was also demonstrated on an integral composite structure. PVA-CNT fiber near the fracture area of the structure recorded very high values when essential damage occurred to the structure. A finite element model of the same structure was developed to predict axial strains at locations of the integral composite structure where the fibers were embedded. The predicted FEA strains were correlated with the experimental measurements from the PVA-CNT fibers. Calculated and experimental values were in good agreement, thus enabling PVA-CNT fibers to be used as strain sensors.

Fiber optics: A brief introduction

International Nuclear Information System (INIS)

Gruchalla, M.E.

1989-01-01

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

Fiber optic hydrophone

Science.gov (United States)

Kuzmenko, Paul J.; Davis, Donald T.

1994-01-01

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

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

Science.gov (United States)

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

2013-12-01

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

Optical fiber stripper positioning apparatus

Science.gov (United States)

Fyfe, Richard W.; Sanchez, Jr., Amadeo

1990-01-01

An optical fiber positioning apparatus for an optical fiber stripping device is disclosed which is capable of providing precise axial alignment between an optical fiber to be stripped of its outer jacket and the cutting blades of a stripping device. The apparatus includes a first bore having a width approximately equal to the diameter of an unstripped optical fiber and a counter bore axially aligned with the first bore and dimensioned to precisely receive a portion of the stripping device in axial alignment with notched cutting blades within the stripping device to thereby axially align the notched cutting blades of the stripping device with the axis of the optical fiber to permit the notched cutting blades to sever the jacket on the optical fiber without damaging the cladding on the optical fiber. In a preferred embodiment, the apparatus further includes a fiber stop which permits determination of the length of jacket to be removed from the optical fiber.

Demonstration of a Fiber Optic Regression Probe

Science.gov (United States)

Korman, Valentin; Polzin, Kurt A.

2010-01-01

The capability to provide localized, real-time monitoring of material regression rates in various applications has the potential to provide a new stream of data for development testing of various components and systems, as well as serving as a monitoring tool in flight applications. These applications include, but are not limited to, the regression of a combusting solid fuel surface, the ablation of the throat in a chemical rocket or the heat shield of an aeroshell, and the monitoring of erosion in long-life plasma thrusters. The rate of regression in the first application is very fast, while the second and third are increasingly slower. A recent fundamental sensor development effort has led to a novel regression, erosion, and ablation sensor technology (REAST). The REAST sensor allows for measurement of real-time surface erosion rates at a discrete surface location. The sensor is optical, using two different, co-located fiber-optics to perform the regression measurement. The disparate optical transmission properties of the two fiber-optics makes it possible to measure the regression rate by monitoring the relative light attenuation through the fibers. As the fibers regress along with the parent material in which they are embedded, the relative light intensities through the two fibers changes, providing a measure of the regression rate. The optical nature of the system makes it relatively easy to use in a variety of harsh, high temperature environments, and it is also unaffected by the presence of electric and magnetic fields. In addition, the sensor could be used to perform optical spectroscopy on the light emitted by a process and collected by fibers, giving localized measurements of various properties. The capability to perform an in-situ measurement of material regression rates is useful in addressing a variety of physical issues in various applications. An in-situ measurement allows for real-time data regarding the erosion rates, providing a quick method for

Improved Optical Fiber Chemical Sensors

Science.gov (United States)

Egalon, Claudio O.; Rogowski, Robert S.

1994-01-01

Calculations, based on exact theory of optical fiber, have shown how to increase optical efficiency sensitivity of active-core, step-index-profile optical-fiber fluorosensor. Calculations result of efforts to improve efficiency of optical-fiber chemical sensor of previous concept described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525). Optical fiber chemical detector of enhanced sensitivity made in several configurations. Portion of fluorescence or chemiluminescence generated in core, and launched directly into bound electromagnetic modes that propagate along core to photodetector.

Integrating Fiber Optic Strain Sensors into Metal Using Ultrasonic Additive Manufacturing

Science.gov (United States)

Hehr, Adam; Norfolk, Mark; Wenning, Justin; Sheridan, John; Leser, Paul; Leser, Patrick; Newman, John A.

2018-03-01

Ultrasonic additive manufacturing, a rather new three-dimensional (3D) printing technology, uses ultrasonic energy to produce metallurgical bonds between layers of metal foils near room temperature. This low temperature attribute of the process enables integration of temperature sensitive components, such as fiber optic strain sensors, directly into metal structures. This may be an enabling technology for Digital Twin applications, i.e., virtual model interaction and feedback with live load data. This study evaluates the consolidation quality, interface robustness, and load sensing limits of commercially available fiber optic strain sensors embedded into aluminum alloy 6061. Lastly, an outlook on the technology and its applications is described.

Optical Fiber Fusion Splicing

CERN Document Server

Yablon, Andrew D

2005-01-01

This book is an up-to-date treatment of optical fiber fusion splicing incorporating all the recent innovations in the field. It provides a toolbox of general strategies and specific techniques that the reader can apply when optimizing fusion splices between novel fibers. It specifically addresses considerations important for fusion splicing of contemporary specialty fibers including dispersion compensating fiber, erbium-doped gain fiber, polarization maintaining fiber, and microstructured fiber. Finally, it discusses the future of optical fiber fusion splicing including silica and non-silica based optical fibers as well as the trend toward increasing automation. Whilst serving as a self-contained reference work, abundant citations from the technical literature will enable readers to readily locate primary sources.

Fiber optic-based biosensor

Science.gov (United States)

Ligler, Frances S.

1991-01-01

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

Cost-effective optical fiber pressure sensor based on intrinsic Fabry-Perot interferometric micro-cavities

Science.gov (United States)

Domingues, M. Fátima; Rodriguez, Camilo A.; Martins, Joana; Tavares, Cátia; Marques, Carlos; Alberto, Nélia; André, Paulo; Antunes, Paulo

2018-05-01

In this work, a cost-effective procedure to manufacture optical fiber pressure sensors is presented. This has a high relevance for integration in robotic exoskeletons or for gait plantar pressure monitoring within the physical rehabilitation scenarios, among other applications. The sensing elements are based on Fabry-Perot interferometric (FPI) micro-cavities, created from the recycling of optical fibers previously destroyed by the catastrophic fuse effect. To produce the pressure sensors, the fiber containing the FPI micro-cavities was embedded in an epoxy resin cylinder used as pressure transducer and responsible to transfer the pressure applied on its surface to the optical fiber containing the FPI micro-cavity. Before the embedding process, some FPI sensors were also characterized to strain variations. After that, the effect of the encapsulation of the FPI structure into the resin was assessed, from which a slight decrease on the FPI interferogram fringes visibility was verified, indicating a small increase in the micro-cavity length. Up on the sensors characterization, a linear dependence of the wavelength shift with the induced pressure was obtained, which leads to a maximum sensitivity of 59.39 ± 1.7 pm/kPa. Moreover, direct dependence of the pressure sensitivity with the micro-cavity volume and length was found.

Enhanced radiation resistant fiber optics

Science.gov (United States)

Lyons, P.B.; Looney, L.D.

1993-11-30

A process for producing an optical fiber having enhanced radiation resistance 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. 4 figures.

Enhanced radiation resistant fiber optics

International Nuclear Information System (INIS)

Lyons, P.B.; Looney, L.D.

1993-01-01

A process for producing an optical fiber having enhanced radiation resistance 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. 4 figures

Full distributed fiber optical sensor for intrusion detection in application to buried pipelines

Science.gov (United States)

Gao, Jianzhong; Jiang, Zhuangde; Zhao, Yulong; Zhu, Li; Zhao, Guoxian

2005-11-01

Based on the microbend effect of optical fiber, a distributed sensor for real-time continuous monitoring of intrusion in application to buried pipelines is proposed. The sensing element is a long cable with a special structure made up of an elastic polymer wire, an optical fiber, and a metal wire. The damage point is located with an embedded optical time domain reflectometry (OTDR) instrument. The intrusion types can be indicated by the amplitude of output voltage. Experimental results show that the detection system can alarm adequately under abnormal load and can locate the intrusion point within 22.4 m for distance of 3.023 km.

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

Science.gov (United States)

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

2013-10-07

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.

Magneto-Optic Field Coupling in Optical Fiber Bragg Gratings

Science.gov (United States)

Carman, Gregory P. (Inventor); Mohanchandra, Panduranga K. (Inventor); Emmons, Michael C. (Inventor); Richards, William Lance (Inventor)

2016-01-01

The invention is a magneto-optic coupled magnetic sensor that comprises a standard optical fiber Bragg grating system. The system includes an optical fiber with at least one Bragg grating therein. The optical fiber has at least an inner core and a cladding that surrounds the inner core. The optical fiber is part of an optical system that includes an interrogation device that provides a light wave through the optical fiber and a system to determine the change in the index of refraction of the optical fiber. The cladding of the optical fiber comprises at least a portion of which is made up of ferromagnetic particles so that the ferromagnetic particles are subject to the light wave provided by the interrogation system. When a magnetic field is present, the ferromagnetic particles change the optical properties of the sensor directly.

Optical fiber spectrophotometer

International Nuclear Information System (INIS)

Zhuang Weixin; Tian Guocheng; Ye Guoan; Zhou Zhihong; Cheng Weiwei; Huang Lifeng; Liu Suying; Tang Yanji; Hu Jingxin; Zhao Yonggang

1998-12-01

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. λ 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

Fiber based optical tweezers for simultaneous in situ force exertion and measurements in a 3D polyacrylamide gel compartment.

Science.gov (United States)

Ti, Chaoyang; Thomas, Gawain M; Ren, Yundong; Zhang, Rui; Wen, Qi; Liu, Yuxiang

2015-07-01

Optical tweezers play an important role in biological applications. However, it is difficult for traditional optical tweezers based on objective lenses to work in a three-dimensional (3D) solid far away from the substrate. In this work, we develop a fiber based optical trapping system, namely inclined dual fiber optical tweezers, that can simultaneously apply and measure forces both in water and in a 3D polyacrylamide gel matrix. In addition, we demonstrate in situ, non-invasive characterization of local mechanical properties of polyacrylamide gel by measurements on an embedded bead. The fiber optical tweezers measurements agree well with those of atomic force microscopy (AFM). The inclined dual fiber optical tweezers provide a promising and versatile tool for cell mechanics study in 3D environments.

Carbon nano tubes embedded in polymer nano fibers

International Nuclear Information System (INIS)

Dror, Y.; Kedem, S.; Khalfin, R.L.; Paz, Y.; Cohenl, Y.; Salalha, Y.; Yarin, A.L.; Zussman, A.

2004-01-01

Full Text: The electro spinning process was used successfully to embed Multi-walled carbon nano tubes (MWCNTs) and single-walled carbon nano tubes (SWCNTs) in a matrix of poly(ethylene oxide) (PEO) forming composite nano fibers. Initial dispersion of SWCNTs in water was achieved by the use of an amphphilic alternating copolymer of styrene and sodium maleate. MWNT dispersion was achieved by ionic and nonionic surfactants. The distribution and conformation of the nano tubes in the nano fibers were studied by transmission electron microscopy (TEM). Oxygen plasma etching was used to expose the nano tubes within the nano fibers to facilitate direct observation. Nano tube alignment within the nano fibers was shown to depend strongly on the quality of the initial dispersions. Well-dispersed and separated nano tubes were embedded in a straight and aligned form while entangled non-separated nano tubes were incorporated as dense aggregates. X-ray diffraction demonstrated a high degree of orientation of the PEO crystals in the electro spun nano fibers with embedded SWCNTs, whereas incorporation of MVCNTs had a detrimental effect on the polymer orientation. Composite polymer nano fibers containing dispersed phases of nanometric TiO 2 particles and MWCNTs were also prepared electro spinning. In this case, the polymer matrix was poly(acrylonitrile) (PAN). The morphology and possible applications of these composite nano fibers will be discussed

Fourier transform infrared (FTIR) fiber optic monitoring of composites during cure in an autoclave

Science.gov (United States)

Druy, Mark A.; Elandjian, Lucy; Stevenson, William A.; Driver, Richard D.; Leskowitz, Garett M.

1990-01-01

Real-time in situ monitoring of the chemical states of epoxy resins was investigated during cure in an autoclave using infrared evanescent spectroscopy. Fiber evanescent sensors were developed which may be sandwiched between the plies of the prepreg sample. A short length of sapphire fiber was used as the sensor cell portion of the fiber probe. Heavy metal fluoride glass optical fiber cables were designed for connecting the FTIR spectrometer to the sensor fiber within the autoclave. The sapphire fibers have outstanding mechanical thermal properties which should permit their use as an embedded link in all thermoset composites. The system is capable of operation at a temperature of 250 C for periods up to 8 hours without major changes to the fiber transmission. A discussion of the selection of suitable sensor fibers, the construction of a fiber-optic interface, and the interpretation of in situ infrared spectra of the curing process is presented.

The effects of embedded piezoelectric fiber composite sensors on the structural integrity of glass-fiber-epoxy composite laminate

Science.gov (United States)

Konka, Hari P.; Wahab, M. A.; Lian, K.

2012-01-01

Piezoelectric fiber composite sensors (PFCSs) made from micro-sized lead zirconate titanate (PZT) fibers have many advantages over the traditional bulk PZT sensors for embedded sensor applications. PFCSs as embedded sensors will be an ideal choice to continuously monitor the stress/strain levels and health conditions of composite structures. PFCSs are highly flexible, easily embeddable, have high compatibility with composite structures, and also provides manufacturing flexibility. This research is focused on examining the effects of embedding PFCS sensors (macro-fiber composite (MFC) and piezoelectric fiber composite (PFC)) on the structural integrity of glass-fiber-epoxy composite laminates. The strengths of composite materials with embedded PFCSs and conventional PZT sensors were compared, and the advantages of PFCS sensors over PZTs were demonstrated. Initially a numerical simulation study is performed to understand the local stress/strain field near the embedded sensor region inside a composite specimen. High stress concentration regions were observed near the embedded sensor corner edge. Using PFCS leads to a reduction of 56% in longitudinal stress concentration and 38% in transverse stress concentration, when compared to using the conventional PZTs as embedded sensors. In-plane tensile, in-plane tension-tension fatigue, and short beam strength tests are performed to evaluate the strengths/behavior of the composite specimens containing embedded PFCS. From the tensile test it is observed that embedding PFCS and PZT sensors in the composite structures leads to a reduction in ultimate strength by 3 and 6% respectively. From the fatigue test results it is concluded that both embedded PFCS and PZT sensors do not have a significant effect on the fatigue behavior of the composite specimens. From the short beam strength test it is found that embedding PFCS and PZT sensors leads to a reduction in shear strength by 7 and 15% respectively. Overall the pure PZT sensors

Fiber Optics Technology.

Science.gov (United States)

Burns, William E.

1986-01-01

Discusses various applications of fiber optics technology: information systems, industrial robots, medicine, television, transportation, and training. Types of jobs that will be available with fiber optics training (such as electricians and telephone cable installers and splicers) are examined. (CT)

Temperature and strain measurements in concrete using micro-structure optical fiber sensors

Energy Technology Data Exchange (ETDEWEB)

Areias, Lou [EURIDICE/SCK - CEN, Mol (Belgium); Vrije Univ. Brussels (Belgium); Geernaert, Thomas; Sulejmani, Sanne [Vrije Univ. Brussels (Belgium); and others

2015-07-01

A recent test carried out to evaluate the construction feasibility of the Belgian supercontainer concept incorporated several types of state-of-the-art sensors and innovative monitoring techniques, including the use of different types of optical fiber sensors. One of these is a relatively new type of sensor developed by the Brussels Photonics Team (B-PHOT) of the Vrije Universiteit Brussel. The sensor uses highly birefringent microstructured optical fibers equipped with fiber Bragg gratings (MOFBGs) sensors. They were embedded in a carbon-fiber reinforced composite plate to provide protection against the concrete's highly alkaline environment, facilitate installation in the concrete mould and allow the transfer of strain onto the fiber. The double reflection spectrum of the MOFBGs allows monitoring strain and temperature simultaneously. This paper presents results of temperature and strain measurements obtained with MOFBG sensors during a {sup 1}/{sub 2}-scale test performed in 2013. The results compare well with similar measurements obtained using conventional thermocouples and vibrating wire strain gauges.

Introduction to optical fiber sensors

International Nuclear Information System (INIS)

Moukdad, S.

1991-01-01

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

Optical fiber switch

Science.gov (United States)

Early, James W.; Lester, Charles S.

2002-01-01

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.

Fiber optics in SHIVA

International Nuclear Information System (INIS)

Severyn, J.; Parker, J.

1978-01-01

SHIVA is a twenty arm laser which is controlled with a network of fifty computers, interconnected with digital fiber optic links. Three different fiber optic systems employed on the Shiva laser will be described. Two of the systems are for digital communications, one at 9600 baud and the other at 1 megabaud. The third system uses fiber optics to distribute diagnostic triggers with subnanosecond jitter

Photometric device using optical fibers

International Nuclear Information System (INIS)

Boisde, Gilbert; Perez, J.-J.

1981-02-01

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

Optical Fiber Protection

Science.gov (United States)

1999-01-01

F&S Inc. developed and commercialized fiber optic and microelectromechanical systems- (MEMS) based instrumentation for harsh environments encountered in the aerospace industry. The NASA SBIR programs have provided F&S the funds and the technology to develop ruggedized coatings and coating techniques that are applied during the optical fiber draw process. The F&S optical fiber fabrication facility and developed coating methods enable F&S to manufacture specialty optical fiber with custom designed refractive index profiles and protective or active coatings. F&S has demonstrated sputtered coatings using metals and ceramics and combinations of each, and has also developed techniques to apply thin coatings of specialized polyimides formulated at NASA Langley Research Center. With these capabilities, F&S has produced cost-effective, reliable instrumentation and sensors capable of withstanding temperatures up to 800? C and continues building commercial sales with corporate partners and private funding. More recently, F&S has adapted the same sensing platforms to provide the rapid detection and identification of chemical and biological agents

Monitoring of railway embankment settlement with fiber-optic pulsed time-of-flight radar.

Science.gov (United States)

Kilpelä, Ari; Lyöri, Veijo; Duan, Guoyong

2012-12-01

This paper deals with a fiber-optic pulsed time-of-flight (PTOF) laser radar used for monitoring the settlement of a railway embankment. The operating principle is based on evaluating the changes in the lengths of the fiber-optic cables embedded in the embankment by measuring the time separation of the optical pulses reflected from both ends of the sensor fiber. The advantage of this method is that it integrates the elongation of the whole sensor, and many sensor fibers can be connected in series. In a field test, seven polyurethane-coated optical cables were installed in a railway embankment and used as 20-m long sensors. The optical timing pulses were created using specially polished optical connectors. The measured precision was 0.28 ps, which corresponds 1.8 μstrain elongation using a 20 m long sensor fiber, using an averaged value of 10,000 pulses for a single measurement value. The averaged elongation value of all sensors was used for cancelling out the effect of temperature variation on the elongation value of each individual sensor. The functionality of the method was tested by digging away a 7.5 m long and approximately 18 mm high section of sand below one sensor. It was measured as a +3 mm change in the length of the sensor fiber, which matched well with the theoretically calculated elongation value, 2.9 mm. The sensor type proved to be strong but flexible enough for this type of use.

Fiber optic chemical sensors: The evolution of high- density fiber-optic DNA microarrays

Science.gov (United States)

Ferguson, Jane A.

2001-06-01

Sensors were developed for multianalyte monitoring, fermentation monitoring, lactate analysis, remote oxygen detection for use in bioremediation monitoring and in a fuel spill clean-up project, heavy metal analysis, and high density DNA microarrays. The major focus of this thesis involved creating and improving high-density DNA gene arrays. Fiber optic sensors are created using fluorescent indicators, polymeric supports, and optical fiber substrates. The fluorescent indicator is entrapped in a polymer layer and attached to the tip of the optical fiber. The tip of the fiber bearing the sensing layer (the distal end) is placed in the sample of interest while the other end of the fiber (the proximal end) is connected to an analysis system. Any length of fiber can be used without compromising the integrity or sensitivity of the system. A fiber optic oxygen sensor was designed incorporating an oxygen sensitive fluorescent dye and a gas permeable polymer attached to an optical fiber. The construction simplicity and ruggedness of the sensor enabled its deployment for in situ chemical oxidation and bioremediation studies. Optical fibers were also used as the substrate to detect biomolecules in solution. To monitor bioprocesses, the production of the analyte of interest must be coupled with a species that is optically measurable. For example, oxygen is consumed in many metabolic functions. The fiber optic oxygen sensor is equipped with an additional sensing layer. Upon contact with a specific biochemical in the sample, a reaction occurs in the additional sensing layer that either consumes or produces oxygen. This dual layer system was used to monitor the presence of lactate, an important metabolite for clinical and bioprocess analysis. In many biological and environmental systems, the generation of one species occurs coincidentally with the generation or consumption of another species. A multianalyte sensor was prepared that can monitor the simultaneous activity of pH, CO2

Recent progress in distributed optical fiber Raman photon sensors at China Jiliang University

Science.gov (United States)

Zhang, Zaixuan; Wang, Jianfeng; Li, Yi; Gong, Huaping; Yu, Xiangdong; Liu, Honglin; Jin, Yongxing; Kang, Juan; Li, Chenxia; Zhang, Wensheng; Zhang, Wenping; Niu, Xiaohui; Sun, Zhongzhou; Zhao, Chunliu; Dong, Xinyong; Jin, Shangzhong

2012-06-01

A brief review of recent progress in researches, productions and applications of full distributed fiber Raman photon sensors at China Jiliang University (CJLU) is presented. In order to improve the measurement distance, the accuracy, the space resolution, the ability of multi-parameter measurements, and the intelligence of full distributed fiber sensor systems, a new generation fiber sensor technology based on the optical fiber nonlinear scattering fusion principle is proposed. A series of new generation full distributed fiber sensors are investigated and designed, which consist of new generation ultra-long distance full distributed fiber Raman and Rayleigh scattering photon sensors integrated with a fiber Raman amplifier, auto-correction full distributed fiber Raman photon temperature sensors based on Raman correlation dual sources, full distributed fiber Raman photon temperature sensors based on a pulse coding source, full distributed fiber Raman photon temperature sensors using a fiber Raman wavelength shifter, a new type of Brillouin optical time domain analyzers (BOTDAs) integrated with a fiber Raman amplifier for replacing a fiber Brillouin amplifier, full distributed fiber Raman and Brillouin photon sensors integrated with a fiber Raman amplifier, and full distributed fiber Brillouin photon sensors integrated with a fiber Brillouin frequency shifter. The Internet of things is believed as one of candidates of the next technological revolution, which has driven hundreds of millions of class markets. Sensor networks are important components of the Internet of things. The full distributed optical fiber sensor network (Rayleigh, Raman, and Brillouin scattering) is a 3S (smart materials, smart structure, and smart skill) system, which is easy to construct smart fiber sensor networks. The distributed optical fiber sensor can be embedded in the power grids, railways, bridges, tunnels, roads, constructions, water supply systems, dams, oil and gas pipelines and other

Miniaturized and general purpose fiber optic ultrasonic sources

International Nuclear Information System (INIS)

Biagi, E.; Fontani, S.; Masotti, L.; Pieraccini, M.

1997-01-01

Innovative photoacoustic sources for ultrasonic NDE, smart structure, and clinical diagnosis are proposed. The working principle is based on thermal conversion of laser pulses into a metallic film evaporated directly onto the tip of a fiber optic. Unique features of the proposed transducers are very high miniaturization and potential easy embedding in smart structure. Additional advantages, high bedding in smart structure. Additional advantages, high ultrasonic frequency, large and flat bandwidth. All these characteristics make the proposed device an ideal ultrasonic source

Nonlinear fiber optics formerly quantum electronics

CERN Document Server

Agrawal, Govind

1995-01-01

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

In Vivo Microscopy Reveals Extensive Embedding of Capillaries within the Sarcolemma of Skeletal Muscle Fibers

Science.gov (United States)

Glancy, Brian; Hsu, Li-Yueh; Dao, Lam; Bakalar, Matthew; French, Stephanie; Chess, David J.; Taylor, Joni L.; Picard, Martin; Aponte, Angel; Daniels, Mathew P.; Esfahani, Shervin; Cushman, Samuel; Balaban, Robert S.

2013-01-01

Objective To provide insight into mitochondrial function in vivo, we evaluated the 3D spatial relationship between capillaries, mitochondria, and muscle fibers in live mice. Methods 3D volumes of in vivo murine Tibialis anterior muscles were imaged by multi-photon microscopy (MPM). Muscle fiber type, mitochondrial distribution, number of capillaries, and capillary-to-fiber contact were assessed. The role of myoglobin-facilitated diffusion was examined in myoglobin knockout mice. Distribution of GLUT4 was also evaluated in the context of the capillary and mitochondrial network. Results MPM revealed that 43.6 ± 3.3% of oxidative fiber capillaries had ≥ 50% of their circumference embedded in a groove in the sarcolemma, in vivo. Embedded capillaries were tightly associated with dense mitochondrial populations lateral to capillary grooves and nearly absent below the groove. Mitochondrial distribution, number of embedded capillaries, and capillary-to-fiber contact were proportional to fiber oxidative capacity and unaffected by myoglobin knockout. GLUT4 did not preferentially localize to embedded capillaries. Conclusions Embedding capillaries in the sarcolemma may provide a regulatory mechanism to optimize delivery of oxygen to heterogeneous groups of muscle fibers. We hypothesize that mitochondria locate to paravascular regions due to myofibril voids created by embedded capillaries, not to enhance the delivery of oxygen to the mitochondria. PMID:25279425

Development of a fiber optic pavement subgrade strain measurement system

Science.gov (United States)

Miller, Craig Emerson

2000-11-01

This dissertation describes the development of a fiber optic sensing system to measure strains within the soil subgrade of highway pavements resulting from traffic loads. The motivation to develop such a device include improvements to: (1)all phases of pavement design, (2)theoretical models used to predict pavement performance, and (3)pavement rehabilitation. The design of the sensing system encompasses selecting an appropriate transducer design as well as the development of optimal optical and demodulation systems. The first is spring based, which attempts to match its spring stiffness to that of the soil-data indicate it is not an optimal transducer design. The second transducer implements anchoring plates attached to two telescoping tubes which allows the soil to be compacted to a desired density between the plates to dictate the transducer's behavior. Both transducers include an extrinsic Fabry- Perot cavity to impose the soil strains onto a phase change of the optical signal propagating through the cavity. The optical system includes a low coherence source and allows phase modulation via path length stretching by adding a second interferometer in series with the transducer, resulting in a path matched differential interferometer. A digitally implemented synthetic heterodyne demodulator based on a four step phase stepping algorithm is used to obtain unambiguous soil strain information from the displacement of the Fabry-Perot cavity. The demodulator is calibrated and characterized by illuminating the transducer with a second long coherence source of different wavelength. The transducer using anchoring plates is embedded within cylindrical soil specimens of varying soil types and soil moisture contents. Loads are applied to the specimen and resulting strains are measured using the embedded fiber optic gage and LVDTs attached to the surface of the specimen. This experimental verification is substantiated using a finite element analysis to predict any differences

Experimental Method of Temperature and Strain Discrimination in Polymer Composite Material by Embedded Fiber-Optic Sensors Based on Femtosecond-Inscribed FBGs

Directory of Open Access Journals (Sweden)

Victor V. Shishkin

2016-01-01

Full Text Available Experimental method of temperature and strain discrimination with fiber Bragg gratings (FBGs sensors embedded in carbon fiber-reinforced plastic is proposed. The method is based on two-fiber technique, when two FBGs inscribed in different fibers with different sensitivities to strain and/or temperature are placed close to each other and act as a single sensing element. The nonlinear polynomial approximation of Bragg wavelength shift as a function of temperature and strain is presented for this method. The FBGs were inscribed with femtosecond laser by point-by-point inscription technique through polymer cladding of the fiber. The comparison of linear and nonlinear approximation accuracies for array of embedded sensors is performed. It is shown that the use of nonlinear approximation gives 1.5–2 times better accuracy. The obtained accuracies of temperature and strain measurements are 2.6–3.8°C and 50–83 με in temperature and strain range of 30–120°C and 0–400 με, respectively.

Passive (self-powered) fiber-optic sensors

International Nuclear Information System (INIS)

McElhaney, S.A.; Falter, D.D.; Todd, R.A.; Simpson, M.L.; Mihalczo, J.T.

1992-01-01

ORNL is developing new group of fiber-optic sensors for characterizing physical aspects such as ambient temperature. These sensors exploit the inherent property of thermographic materials that the lifetime and/or intensity of the emitted fluorescence decreases with increasing temperature. Unlike current fluorescent temperature sensors that use a light source for excitation, these sensors are totally passive (self-powered) and use either an embedded or external radiation source. A proof-of-principle temperature sensor was developed, based on this concept, using a well-known thermographic material, magnesium fluorogermanate. Experimental results showed that the radiation-induced fluorescence resulted in an intensity change but no significant decay rate change with increasing temperature

Fiber Optics Instrumentation Development

Science.gov (United States)

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

2010-01-01

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

Fiber Optics and Library Technology.

Science.gov (United States)

Koenig, Michael

1984-01-01

This article examines fiber optic technology, explains some of the key terminology, and speculates about the way fiber optics will change our world. Applications of fiber optics to library systems in three major areas--linkage of a number of mainframe computers, local area networks, and main trunk communications--are highlighted. (EJS)

Electrospun amplified fiber optics.

Science.gov (United States)

Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

2015-03-11

All-optical signal processing is the focus of much research aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for efficient signal transmission. However, the complex fabrication methods involving high-temperature processes performed in a highly pure environment slow the fabrication process and make amplified components expensive with respect to an ideal, high-throughput, room temperature production. Here, we report on near-infrared polymer fiber amplifiers working over a band of ∼20 nm. The fibers are cheap, spun with a process entirely carried out at room temperature, and shown to have amplified spontaneous emission with good gain coefficients and low levels of optical losses (a few cm(-1)). The amplification process is favored by high fiber quality and low self-absorption. The found performance metrics appear to be suitable for short-distance operations, and the large variety of commercially available doping dyes might allow for effective multiwavelength operations by electrospun amplified fiber optics.

FIBER OPTIC LIGHTING SYSTEMS

Directory of Open Access Journals (Sweden)

Munir BATUR

2013-01-01

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

Poincare ball embeddings of the optical geometry

International Nuclear Information System (INIS)

Abramowicz, M A; Bengtsson, I; Karas, V; Rosquist, K

2002-01-01

It is shown that the optical geometry of the Reissner-Nordstroem exterior metric can be embedded in a hyperbolic space all the way down to its outer horizon. The adopted embedding procedure removes a breakdown of flat-space embeddings which occurs outside the horizon, at and below the Buchdahl-Bondi limit (R/M=9/4 in the Schwarzschild case). In particular, the horizon can be captured in the optical geometry embedding diagram. Moreover, by using the compact Poincare ball representation of the hyperbolic space, the embedding diagram can cover the whole extent of radius from spatial infinity down to the horizon. Attention is drawn to the advantages of such embeddings in an appropriately curved space: this approach gives compact embeddings and it clearly distinguishes the case of an extremal black hole from a non-extremal one in terms of the topology of the embedded horizon

Fiber-optic seismic sensor

International Nuclear Information System (INIS)

Finch, G. W.; Udd, E.

1985-01-01

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

Chemistry Research of Optical Fibers.

Science.gov (United States)

1982-09-27

BROADENING IN OPTICAL FIBERS Herbert B. Rosenstock* Naval Research Laboratory Washington, DC 20375 ABSTRACT A light pulse transmitted through a fiber...Marcatili, Marcuse , and Personick, "Dispersion Properties of Fibers" (Ch. 4 in "Optical Fiber Telecommunications," S. E. Miller and A. C. Chynoweth, eds

Multimode optical fiber

Science.gov (United States)

Bigot-Astruc, Marianne; Molin, Denis; Sillard, Pierre

2014-11-04

A depressed graded-index multimode optical fiber includes a central core, an inner depressed cladding, a depressed trench, an outer depressed cladding, and an outer cladding. The central core has an alpha-index profile. The depressed claddings limit the impact of leaky modes on optical-fiber performance characteristics (e.g., bandwidth, core size, and/or numerical aperture).

Overview of Fiber-Optical Sensors

Science.gov (United States)

Depaula, Ramon P.; Moore, Emery L.

1987-01-01

Design, development, and sensitivity of sensors using fiber optics reviewed. State-of-the-art and probable future developments of sensors using fiber optics described in report including references to work in field. Serves to update previously published surveys. Systems incorporating fiber-optic sensors used in medical diagnosis, navigation, robotics, sonar, power industry, and industrial controls.

Optical fiber-applied radiation detection system

International Nuclear Information System (INIS)

Nishiura, Ryuichi; Uranaka, Yasuo; Izumi, Nobuyuki

2001-01-01

A technique to measure radiation by using plastic scintillation fibers doped radiation fluorescent (scintillator) to plastic optical fiber for a radiation sensor, was developed. The technique contains some superiority such as high flexibility due to using fibers, relatively easy large area due to detecting portion of whole of fibers, and no electromagnetic noise effect due to optical radiation detection and signal transmission. Measurable to wide range of and continuous radiation distribution along optical fiber cable at a testing portion using scintillation fiber and flight time method, the optical fiber-applied radiation sensing system can effectively monitor space radiation dose or apparatus operation condition monitoring. And, a portable type scintillation optical fiber body surface pollution monitor can measure pollution concentration of radioactive materials attached onto body surface by arranging scintillation fiber processed to a plate with small size and flexibility around a man to be tested. Here were described on outline and fundamental properties of various application products using these plastic scintillation fiber. (G.K.)

Career Directions--Fiber Optic Installer

Science.gov (United States)

Tech Directions, 2012

2012-01-01

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

Assessment of fiber optic pressure sensors

International Nuclear Information System (INIS)

Hashemian, H.M.; Black, C.L.; Farmer, J.P.

1995-04-01

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

Fiber optics standard dictionary

CERN Document Server

Weik, Martin H

1997-01-01

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

Dynamic Strain Measurements on Automotive and Aeronautic Composite Components by Means of Embedded Fiber Bragg Grating Sensors

Directory of Open Access Journals (Sweden)

Alfredo Lamberti

2015-10-01

Full Text Available The measurement of the internal deformations occurring in real-life composite components is a very challenging task, especially for those components that are rather difficult to access. Optical fiber sensors can overcome such a problem, since they can be embedded in the composite materials and serve as in situ sensors. In this article, embedded optical fiber Bragg grating (FBG sensors are used to analyze the vibration characteristics of two real-life composite components. The first component is a carbon fiber-reinforced polymer automotive control arm; the second is a glass fiber-reinforced polymer aeronautic hinge arm. The modal parameters of both components were estimated by processing the FBG signals with two interrogation techniques: the maximum detection and fast phase correlation algorithms were employed for the demodulation of the FBG signals; the Peak-Picking and PolyMax techniques were instead used for the parameter estimation. To validate the FBG outcomes, reference measurements were performed by means of a laser Doppler vibrometer. Sensors 2015, 15 27175 The analysis of the results showed that the FBG sensing capabilities were enhanced when the recently-introduced fast phase correlation algorithm was combined with the state-of-the-art PolyMax estimator curve fitting method. In this case, the FBGs provided the most accurate results, i.e. it was possible to fully characterize the vibration behavior of both composite components. When using more traditional interrogation algorithms (maximum detection and modal parameter estimation techniques (Peak-Picking, some of the modes were not successfully identified.

On the mechanical coupling of a fiber optic cable used for distributed acoustic/vibration sensing applications—a theoretical consideration

Science.gov (United States)

Reinsch, Thomas; Thurley, Tom; Jousset, Philippe

2017-12-01

In recent years, fiber optic cables are increasingly used for the acquisition of dynamic strain changes for seismic surveys. When considering seismic amplitudes, one of the first questions arising is the mechanical coupling between optical fiber and the surrounding medium. Here we analyse the interaction of ground movement with a typical telecom-grade fiber optic cable from an existing telecommunication network deployed in a sand filled trench at the surface. Within the cable, the optical fiber is embedded in a gel-filled plastic tube. We apply Hooke’s law to calculate the stress needed to strain the optical fiber throughout the cable structure. In case the stress magnitude at the cable-sand interface as well as the gel-optical fiber interface is below the yield strength of the respective material, sand and gel, it can be regarded as an elastic medium. Hence, a multilayer radial symmetric model can be used to calculate the coupling of the optical fiber with the surrounding medium. We show that the transfer function has a -3 dB lower cut-off wavelength of about 22 m. The magnitude response of this telecom-grade fiber optic cable is therefore almost perfect at typical low frequency seismic waves. The approach presented here can be applied to various cable designs to estimate the strain transfer between ground movement and an optical fiber.

High pressure fiber optic sensor system

Science.gov (United States)

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

2013-11-26

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

Catching Attention in Fiber Optics Class

OpenAIRE

Kezerashvili, R. Ya.; Leng, L.

2004-01-01

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.

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

Science.gov (United States)

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

2014-08-01

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

Embedded Fiber Optic Sensors for Integral Armor

National Research Council Canada - National Science Library

Fink, Bruce

2000-01-01

This report describes the work performed with Production Products Manufacturing & Sales (PPMS), Inc., under the "Liquid Molded Composite Armor Smart Structures Using Embedded Sensors" Small Business Innovative Research...

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

DEFF Research Database (Denmark)

Gu, Bobo; Yuan, Scott Wu; Frosz, Michael H.

2012-01-01

We demonstrate a nonlinear fiber-optic strain sensor, which uses the shifts of four-wave mixing Stokes and anti-Stokes peaks caused by the strain-induced changes in the structure and refractive index of a microstructured optical fiber. The sensor thus uses the inherent nonlinearity of the fiber a...

Realization of fiber optic displacement sensors

Science.gov (United States)

Guzowski, Bartlomiej; Lakomski, Mateusz

2018-03-01

Fiber optic sensors are very promising because of their inherent advantages such as very small size, hard environment tolerance and impact of electromagnetic fields. In this paper three different types of Intensity Fiber Optic Displacement Sensors (I-FODS) are presented. Three configurations of I-FODS were realized in two varieties. In the first one, the cleaved multimode optical fibers (MMF) were used to collect reflected light, while in the second variety the MMF ended with ball lenses were chosen. To ensure an accurate alignment of optical fibers in the sensor head the MTP C9730 optical fiber ferrules were used. In this paper the influence of distribution of transmitting and detecting optical fibers on sensitivity and linear range of operation of developed I-FODS were investigated. We have shown, that I-FODS with ball lenses receive average 10.5% more reflected power in comparison to the cleaved optical fibers and they increase linearity range of I-FODS by 33%. In this paper, an analysis of each type of the realized sensor and detailed discussion are given.

Fiber optic sensor and method for making

Science.gov (United States)

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

2010-05-18

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

System for testing optical fibers

Science.gov (United States)

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

1980-07-15

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.

Radiation resistance of optical fibers, (10)

International Nuclear Information System (INIS)

Tsunoda, Tsunemi; Ara, Katsuyuki; Morimoto, Naoki; Sanada, Kazuo; Inada, Koichi.

1991-01-01

Optical fibers have many excellent characteristics such as the light weight of the material, insulation, the noninductivity of electromagnetic interference noise, the wide band of signal transmission, and small loss. Also in the field of atomic energy, the utilization of optical fibers is positively expanded, and the research on the method of application and so on has been advanced. However in optical fibers, there is the problem that color centers are formed at the relatively low level of radiation, and they are colored. Accordingly, for effectively utilizing optical fibers in radiation environment, it is indispensable to improve their radiation resistance. For the purpose of solving this problem, the authors have carried out the basic research on the effect that radiation exerts to optical fibers and the development of the optical fibers having excellent radiation resistance. For the purpose of expanding the range of application of GeO 2 -doped silica core fibers including GI type in radiation regions, the transmission characteristics of the fibers during irradiation were examined by using the Cl content as the parameter. Therefore, the results are reported. The fibers put to the test, the testing method and the results are described. (K.I.)

Time domain optical spectrometry with fiber optic waveguides

International Nuclear Information System (INIS)

Whitten, W.B.

1983-01-01

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

Fiber Optic Calorimetry

International Nuclear Information System (INIS)

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

1997-01-01

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 (microrad) 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% 240 Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

Fiber optic calorimetry

International Nuclear Information System (INIS)

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

1998-01-01

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 microrad 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% 240 Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

Applications of nonlinear fiber optics

CERN Document Server

Agrawal, Govind

2008-01-01

* The only book describing applications of nonlinear fiber optics * Two new chapters on the latest developments: highly nonlinear fibers and quantum applications* Coverage of biomedical applications* Problems provided at the end of each chapterThe development of new highly nonlinear fibers - referred to as microstructured fibers, holey fibers and photonic crystal fibers - is the next generation technology for all-optical signal processing and biomedical applications. This new edition has been thoroughly updated to incorporate these key technology developments.The bo

Collapsed optical fiber: A novel method for improving thermoluminescence response of optical fiber

Energy Technology Data Exchange (ETDEWEB)

Mahdiraji, G. Amouzad, E-mail: ghafour@um.edu.my [Integrated Lightwave Research Group, Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Adikan, F.R. Mahamd [Integrated Lightwave Research Group, Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Bradley, D.A. [Department of Physics, University of Surrey, Guildford, GU2 7XH (United Kingdom); Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2015-05-15

A new technique is shown to provide improved thermoluminescence (TL) response from optical fibers, based on collapsing down hollow capillary optical fibers (COF) into flat fibers (FF), producing fused inner walls and consequent defects generation. Four different fused silica preform tubes are used to fabricate in-house COFs and FFs, i.e., ultra-pure (F300), relatively pure silica (PS), germanium-doped (Ge), and Ge–Boron-doped (GeB). The optical fibers are then subjected to 6 MeV electron irradiation. While the results show similar TL response from F300-COF and -FF, the TL response of PS-COF is improved by a factor of 6 by collapsing it down to a FF. By doping Ge into the F300 tube, the TL response of the resultant Ge-COF shows an improvement of 3 times over that of F300-COF, while an improvement of a factor of 12 is obtained by producing a Ge-FF. In GeB preform, by collapsing the capillary fiber into a FF, an improvement in TL response of 31 times that of GeB-COF is obtained. TL glow curve analysis shows an additional peak to be generated in the FFs compared to that observed in the COFs. The TL intensity value of the new peak is significantly increased in the doped FFs compared to the undoped FFs. The results suggest that defects generation occurs as a result of the fusing/collapsing technique, providing a TL response from the optical fibers that can substantially improve upon that of existing TL system sensitivities. - Highlights: • A new method for increasing TL response of optical fiber is presented. • By collapsing capillary fiber wall surface, TL response of the fiber increased. • By adding impurity in the collapsing area, TL response significantly improved.

Optical-domain Compensation for Coupling between Optical Fiber Conjugate Vortex Modes

DEFF Research Database (Denmark)

Lyubopytov, Vladimir S.; Tatarczak, Anna; Lu, Xiaofeng

2016-01-01

We demonstrate for the first time optical-domain compensation for coupling between conjugate vortex modes in optical fibers. We introduce a novel method for reconstructing the complex propagation matrix of the optical fiber with straightforward implementation.......We demonstrate for the first time optical-domain compensation for coupling between conjugate vortex modes in optical fibers. We introduce a novel method for reconstructing the complex propagation matrix of the optical fiber with straightforward implementation....

Eliminating Crystals in Non-Oxide Optical Fiber Preforms and Optical Fibers

Science.gov (United States)

Tucker, Dennis S.; LaPointe, Michael R.

2012-01-01

Non ]oxide fiber optics such as heavy metal fluoride and chalcogenide glasses are extensively used in infrared transmitting applications such as communication systems, chemical sensors, and laser fiber guides for cutting, welding and medical surgery. The addition of rare earths such as erbium, enable these materials to be used as fiber laser and amplifiers. Some of these glasses however are very susceptible to crystallization. Even small crystals can lead to light scatter and a high attenuation coefficient, limiting their usefulness. Previously two research teams found that microgravity suppressed crystallization in heavy metal fluoride glasses. Looking for a less expensive method to suppress crystallization, ground based research was performed utilizing an axial magnetic field. The experiments revealed identical results to those obtained via microgravity processing. This research then led to a patented process for eliminating crystals in optical fiber preforms and the resulting optical fibers. In this paper, the microgravity results will be reviewed as well as patents and papers relating to the use of magnetic fields in various material and glass processing applications. Finally our patent to eliminate crystals in non ]oxide glasses utilizing a magnetic field will be detailed.

Optical fibers and RF a natural combination

CERN Document Server

Romeiser, Malcolm

2004-01-01

The optical fiber industry has experienced a period of consolidation and reorganization and is now poised for a new surge in growth. To take advantage of that growth, and to respond to the demand to use fiber more efficiently, designers need a better understanding of fiber optics. Taking the approach that optical fibers are an extension of RF-based communications, the author explains basic optical concepts, applications, and systems; the nature and performance characteristics of optical fibers; and optical sources, connectors and splices. Subsequent chapters explore current applications of fib

Optical fibers and their applications for radiation measurements

International Nuclear Information System (INIS)

Kakuta, Tsunemi

1998-01-01

As a new method of radiation measurements, several optical methods using optical fiber sensors have been developed. One is the application of 'radio-luminescence' from the optical fiber itself such as plastic scintillating fibers. Other researches are made to develop the 'combined-sensors' by combination of optical fibers and scintillating materials. Using the time domain method of optical fiber sensors, the profile of radiation distribution along the optical fiber can be easily determined. A multi-parameter sensing system for measurement of radiation, temperature, stress, etc, are also expected using these optical fiber sensors. (author)

Shedding Light on Fiber Optics.

Science.gov (United States)

Bunch, Robert M.

1994-01-01

Explains the principles of fiber optics as a medium for light-wave communication. Current uses of fiber systems on college campuses include voice, video, and local area network applications. A group of seven school districts in Minnesota are linked via fiber-optic cables. Other uses are discussed. (MLF)

Optical fiber communications

CERN Document Server

Keiser, Gerd

2008-01-01

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

Engineering modes in optical fibers with metamaterial

DEFF Research Database (Denmark)

Yan, Min; Mortensen, Asger; Qiu, Min

2009-01-01

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

A fiber-optic polarimetric demonstration kit

International Nuclear Information System (INIS)

Eftimov, T; Dimitrova, T L; Ivanov, G

2012-01-01

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.

An inexpensive high-temperature optical fiber thermometer

International Nuclear Information System (INIS)

Moore, Travis J.; Jones, Matthew R.; Tree, Dale R.; Allred, David D.

2017-01-01

An optical fiber thermometer consists of an optical fiber whose tip is coated with a highly conductive, opaque material. When heated, this sensing tip becomes an isothermal cavity that emits like a blackbody. This emission is used to predict the sensing tip temperature. In this work, analytical and experimental research has been conducted to further advance the development of optical fiber thermometry. An inexpensive optical fiber thermometer is developed by applying a thin coating of a high-temperature cement onto the tip of a silica optical fiber. An FTIR spectrometer is used to detect the spectral radiance exiting the fiber. A rigorous mathematical model of the irradiation incident on the detection system is developed. The optical fiber thermometer is calibrated using a blackbody radiator and inverse methods are used to predict the sensing tip temperature when exposed to various heat sources. - Highlights: • An inexpensive coating for an optical fiber thermometer sensing tip is tested. • Inverse heat transfer methods are used to estimate the sensing tip temperature. • An FTIR spectrometer is used as the detector to test the optical fiber thermometer using various heat sources.

Using embedded fibers to measure explosive detonation velocities

Energy Technology Data Exchange (ETDEWEB)

Podsednik, Jason W.; Parks, Shawn Michael; Navarro, Rudolfo J.

2012-07-01

Single-mode fibers were cleverly embedded into fixtures holding nitromethane, and used in conjunction with a photonic Doppler velocimeter (PDV) to measure the associated detonation velocity. These measurements have aided us in our understanding of energetic materials and enhanced our diagnostic capabilities.

Novel Fiber-Optic Ring Acoustic Emission Sensor.

Science.gov (United States)

Wei, Peng; Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao

2018-01-13

Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

Fiber optics welder

Science.gov (United States)

Higgins, R.W.; Robichaud, R.E.

A system is described 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/sup 0/ 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.

Fiber optic neutron imaging system: calibration

International Nuclear Information System (INIS)

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

1981-01-01

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

Optical fibers for FTTH application

Science.gov (United States)

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

2013-07-01

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.

Optical Fiber for High-Power Optical Communication

Directory of Open Access Journals (Sweden)

Kenji Kurokawa

2012-09-01

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.

Novel Fiber-Optic Ring Acoustic Emission Sensor

Directory of Open Access Journals (Sweden)

Peng Wei

2018-01-01

Full Text Available Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

Enhancing Optical Communications with Brand New Fibers

DEFF Research Database (Denmark)

Morioka, Toshio; Awaji, Yoshinari; Ryf, Roland

2012-01-01

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

Applications of fiber optics in physical protection

International Nuclear Information System (INIS)

Buckle, T.H.

1994-03-01

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

Fiber fuse light-induced continuous breakdown of silica glass optical fiber

CERN Document Server

Todoroki, Shin-ichi

2014-01-01

This book describes the fiber fuse phenomenon that causes a serious problem for the present optical communication systems. High-power light often brings about catastrophic damage to optical devices. Silica glass optical fibers with ultralow transmission loss are not the exception. A fiber fuse appears in a heated region of the fiber cable delivering a few watts of light and runs toward the light source destroying its core region. Understanding this phenomenon is a necessary first step in the development of future optical communication systems. This book provides supplementary videos and photog

Handbook of fiber optics theory and applications

CERN Document Server

Yeh, Chai

2013-01-01

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

Optical pulse generation using fiber lasers and integrated optics

International Nuclear Information System (INIS)

Wilcox, R.B.; Browning, D.F.; Burkhart, S.C.; VanWonterghem, B.W.

1995-01-01

We have demonstrated an optical pulse forming system using fiber and integrated optics, and have designed a multiple-output system for a proposed fusion laser facility. Our approach is an advancement over previous designs for fusion lasers, and an unusual application of fiber lasers and integrated optics

Fiber optic fire detection technology

International Nuclear Information System (INIS)

Hering, D.W.

1990-01-01

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

Polymer optical fiber bragg grating sensors

DEFF Research Database (Denmark)

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

2010-01-01

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

Behavior of optical fibers under heavy irradiation

International Nuclear Information System (INIS)

Kakuta, T.; Sagawa, T.

1998-01-01

Several kinds of optical diagnostics are planned in a fusion reactor. Complicated optical systems such as periscopes are thought to be primary candidates for optical measurements, especially for visible wavelengths. However, optical fibers have several advantages over such optical systems. Also, the optical fibers could be a far better transmission line for signals under a high electromagnetic field. However, they have been considered vulnerable to heavy irradiation. In this study, several kinds of optical fibers were irradiated in the JMTR fission reactor. The optical transmissivity in fibers was measured in situ during fast neutron and gamma irradiation, up to doses of 2 x 10 24 n m -2 and 5 x 10 9 Gy, respectively. The irradiation temperature ranged from 300 to 700 K. For pure ionizing irradiation environments, some methods for improving the radiation resistance of optical fibers were indicated. The results showed that effects of the irradiation associated with fast neutrons would be different from the effects of pure ionizing irradiation. Some fibers were found to withstand the heavy irradiation, especially in an infrared wavelength range. (orig.)

Refractive index retrieving of polarization maintaining optical fibers

Science.gov (United States)

Ramadan, W. A.; Wahba, H. H.; Shams El-Din, M. A.; Abd El-Sadek, I. G.

2018-01-01

In this paper, the cross-section images, of two different types of polarization maintaining (PM) optical fibers, are employed to estimate the optical phase variation due to transverse optical rays passing through these optical fibers. An adaptive algorithm is proposed to recognize the different areas constituting the PM optical fibers cross-sections. These areas are scanned by a transverse beam to calculate the optical paths for given values of refractive indices. Consequently, the optical phases across the PM optical fibers could be recovered. PM optical fiber is immersed in a matching fluid and set in the object arm of Mach-Zehnder interferometer. The produced interferograms are analyzed to extract the optical phases caused by the PM optical fibers. The estimated optical phases could be optimized to be in good coincidence with experimentally extracted ones. This has been achieved through changing of the PM optical fibers refractive indices to retrieve the correct values. The correct refractive indices values are confirmed by getting the best fit between the estimated and the extracted optical phases. The presented approach is a promising one because it provides a quite direct and accurate information about refractive index, birefringence and beat length of PM optical fibers comparing with different techniques handle the same task.

Dynamically tunable optical bottles from an optical fiber

DEFF Research Database (Denmark)

Chen, Yuhao; Yan, Lu; Rishøj, Lars Søgaard

2012-01-01

Optical fibers have long been used to impose spatial coherence to shape free-space optical beams. Recent work has shown that one can use higher order fiber modes to create more exotic beam profiles. We experimentally generate optical bottles from Talbot imaging in the coherent superposition of two...... fiber modes excited with long period gratings, and obtain a 28 μm × 6 μm bottle with controlled contrast up to 10.13 dB. Our geometry allows for phase tuning of one mode with respect to the other, which enables us to dynamically move the bottle in free space....

Optical fiber end-facet polymer suspended-mirror devices

Science.gov (United States)

Yao, Mian; Wu, Jushuai; Zhang, A. Ping; Tam, Hwa-Yaw; Wai, P. K. A.

2017-04-01

This paper presents a novel optical fiber device based on a polymer suspended mirror on the end facet of an optical fiber. With an own-developed optical 3D micro-printing technology, SU-8 suspended-mirror devices (SMDs) were successfully fabricated on the top of a standard single-mode optical fiber. Optical reflection spectra of the fabricated SU- 8 SMDs were measured and compared with theoretical analysis. The proposed technology paves a way towards 3D microengineering of the small end-facet of optical fibers to develop novel fiber-optic sensors.

Application of Fiber Optic Instrumentation

Science.gov (United States)

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

2012-01-01

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

Optical Characterization of Doped Thermoplastic and Thermosetting Polymer-Optical-Fibers

Directory of Open Access Journals (Sweden)

Igor Ayesta

2017-03-01

Full Text Available The emission properties of a graded-index thermoplastic polymer optical fiber and a step-index thermosetting one, both doped with rhodamine 6G, have been studied. The work includes a detailed analysis of the amplified spontaneous emission together with a study of the optical gains and losses of the fibers. The photostability of the emission of both types of fibers has also been investigated. Comparisons between the results of both doped polymer optical fibers are presented and discussed.

Fiber optic vibration sensor using bifurcated plastic optical fiber

Science.gov (United States)

Abdullah, M.; Bidin, N.; Yasin, M.

2016-11-01

An extrinsic fiber optic vibration sensor is demonstrated for a fiber optic displacement sensor based on a bundled multimode fiber to measure a vibration frequency ranging from 100 until 3000 Hz. The front slope has a sensitivity of 0.1938mV/mm and linearity of 99.7% within a measurement range between 0.15-3.00 mm. By placing the diaphragm of the concave load-speaker within the linear range from the probe, the frequency of the vibration can be measured with error percentage of less than 1.54%. The graph of input against output frequency for low, medium and high frequency range show very high linearity up to 99%. Slope for low, medium, and high frequency range are calculated as 1.0026, 0.9934, and 1.0007 respectively. Simplicity, long term stability, low power consumption, wide dynamic and frequency ranges, noise reduction, ruggedness, linearity and light weight make it promising alternative to other well-establish methods for vibration frequency measurement.

Accurate mode characterization of two-mode optical fibers by in-fiber acousto-optics.

Science.gov (United States)

Alcusa-Sáez, E; Díez, A; Andrés, M V

2016-03-07

Acousto-optic interaction in optical fibers is exploited for the accurate and broadband characterization of two-mode optical fibers. Coupling between LP 01 and LP 1m modes is produced in a broadband wavelength range. Difference in effective indices, group indices, and chromatic dispersions between the guided modes, are obtained from experimental measurements. Additionally, we show that the technique is suitable to investigate the fine modes structure of LP modes, and some other intriguing features related with modes' cut-off.

Fiber-optic polarization diversity detection for rotary probe optical coherence tomography.

Science.gov (United States)

Lee, Anthony M D; Pahlevaninezhad, Hamid; Yang, Victor X D; Lam, Stephen; MacAulay, Calum; Lane, Pierre

2014-06-15

We report a polarization diversity detection scheme for optical coherence tomography with a new, custom, miniaturized fiber coupler with single mode (SM) fiber inputs and polarization maintaining (PM) fiber outputs. The SM fiber inputs obviate matching the optical lengths of the X and Y OCT polarization channels prior to interference and the PM fiber outputs ensure defined X and Y axes after interference. Advantages for this scheme include easier alignment, lower cost, and easier miniaturization compared to designs with free-space bulk optical components. We demonstrate the utility of the detection system to mitigate the effects of rapidly changing polarization states when imaging with rotating fiber optic probes in Intralipid suspension and during in vivo imaging of human airways.

Optical Fiber Thermometer Based on Fiber Bragg Gratings

Science.gov (United States)

Rosli, Ekbal Bin; Mohd. Noor, Uzer

2018-03-01

Fiber Bragg grating has generated much interest in use as sensors to measure strain, temperature, and other physical parameters. It also the most common component used to develop this sensor with the advantages of simple, intrinsic sensing elements, electrically passive operation, EMI immunity, high sensitivity, compact size and potentially low cost [6]. This paper reports the design of an optical fiber thermometer based on fiber Bragg gratings. The system was developed for detecting temperature and strain by monitoring the shift of Bragg wavelength. The shifting of Bragg wavelength is used to indicate the temperature and strain due to the change in the surrounding temperature and strain. When the temperature and strain reach the exact wavelength level of the system, the temperature and strain value will display on the Arduino liquid crystal display (LCD). The optical fiber will provide the broadband light source and after passing the FBG the Bragg wavelength into the optical spectrum analyzer (OSA). The system is based on FBG as a physical quantity sensor. The temperatures measured is taken from the water bath and that of the strain is provided by amount of slotted mass used. The outcome of this project is to characterize the Bragg wavelength shifting from the fiber Bragg grating output. As the conclusion, this project provides an efficient optical fiber thermometer in measuring temperature and strain in order to replace the use of conventional electrical instruments.

Demonstration of a Fiber Optic Regression Probe in a High-Temperature Flow

Science.gov (United States)

Korman, Valentin; Polzin, Kurt

2011-01-01

The capability to provide localized, real-time monitoring of material regression rates in various applications has the potential to provide a new stream of data for development testing of various components and systems, as well as serving as a monitoring tool in flight applications. These applications include, but are not limited to, the regression of a combusting solid fuel surface, the ablation of the throat in a chemical rocket or the heat shield of an aeroshell, and the monitoring of erosion in long-life plasma thrusters. The rate of regression in the first application is very fast, while the second and third are increasingly slower. A recent fundamental sensor development effort has led to a novel regression, erosion, and ablation sensor technology (REAST). The REAST sensor allows for measurement of real-time surface erosion rates at a discrete surface location. The sensor is optical, using two different, co-located fiber-optics to perform the regression measurement. The disparate optical transmission properties of the two fiber-optics makes it possible to measure the regression rate by monitoring the relative light attenuation through the fibers. As the fibers regress along with the parent material in which they are embedded, the relative light intensities through the two fibers changes, providing a measure of the regression rate. The optical nature of the system makes it relatively easy to use in a variety of harsh, high temperature environments, and it is also unaffected by the presence of electric and magnetic fields. In addition, the sensor could be used to perform optical spectroscopy on the light emitted by a process and collected by fibers, giving localized measurements of various properties. The capability to perform an in-situ measurement of material regression rates is useful in addressing a variety of physical issues in various applications. An in-situ measurement allows for real-time data regarding the erosion rates, providing a quick method for

Microstructured Optical Fiber for X-ray Detection

Science.gov (United States)

DeHaven, Stanton L.

2009-01-01

A novel scintillating optical fiber is presented using a composite micro-structured quartz optical fiber. Scintillating materials are introduced into the multiple inclusions of the fiber. This creates a composite optical fiber having quartz as a cladding with an organic scintillating material core. X-ray detection using these fibers is compared to a collimated cadmium telluride (CdTe) detector over an energy range from 10 to 40 keV. Results show a good correlation between the fiber count rate trend and that of the CdTe detector.

Characterization of electrogenerated polypyrrole-benzophenone films coated on poly(pyrrole-methyl metacrylate) optic-conductive fibers.

Science.gov (United States)

Abu-Rabeah, Khalil; Atias, Danit; Herrmann, Sebastien; Frenkel, Julia; Tavor, Dorith; Cosnier, Serge; Marks, Robert S

2009-09-01

A conductive surface was created for the development of a biosensing platform via chemical polymerization of pyrrole onto the surface of poly(methyl methacrylate) (PMMA) fibers, with a subsequent electrogeneration of a photoactive linker pyrrole-benzophenone (PyBz) monomer on the fiber surface. Irradiation of the benzophenone groups embedded in the polypyrrole (Ppy) films by UV (350 nm) formed active radicals, allowing covalent attachment of the desired biomaterials. Characterization and optimization of this platform were carried out, with the platform showing conductive, stable, thin, controllable, and light-transmissible film features. Various parameters such as time deposition, process temperature, and activator plus pyrrole monomer concentrations were examined in the study. The morphology and permeability of the optic-fiber PMMA fibers were investigated to examine mass transfer ability. Cyclic voltammetry and amperometry techniques were applied to characterize the electrical features of the surface and charge transfer. The platform potential was then demonstrated by the construction of both amperometric and optical biosensors.

Laboratory Equipment Type Fiber Optic Refractometer

Directory of Open Access Journals (Sweden)

E. F. Carome

2002-09-01

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

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

DEFF Research Database (Denmark)

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

2010-01-01

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

Distributed Fiber-Optic Sensors for Vibration Detection.

Science.gov (United States)

Liu, Xin; Jin, Baoquan; Bai, Qing; Wang, Yu; Wang, Dong; Wang, Yuncai

2016-07-26

Distributed fiber-optic vibration sensors receive extensive investigation and play a significant role in the sensor panorama. Optical parameters such as light intensity, phase, polarization state, or light frequency will change when external vibration is applied on the sensing fiber. In this paper, various technologies of distributed fiber-optic vibration sensing are reviewed, from interferometric sensing technology, such as Sagnac, Mach-Zehnder, and Michelson, to backscattering-based sensing technology, such as phase-sensitive optical time domain reflectometer, polarization-optical time domain reflectometer, optical frequency domain reflectometer, as well as some combinations of interferometric and backscattering-based techniques. Their operation principles are presented and recent research efforts are also included. Finally, the applications of distributed fiber-optic vibration sensors are summarized, which mainly include structural health monitoring and perimeter security, etc. Overall, distributed fiber-optic vibration sensors possess the advantages of large-scale monitoring, good concealment, excellent flexibility, and immunity to electromagnetic interference, and thus show considerable potential for a variety of practical applications.

Optical fiber sensors for harsh environments

Science.gov (United States)

Xu, Juncheng; Wang, Anbo

2007-02-06

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

Fiber optic calorimetry

International Nuclear Information System (INIS)

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

1998-01-01

A twin-bridge calorimeter using optical fiber as the sensor element was constructed and tested. This system demonstrates the principle and capability of using fiber 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 microradian (μrad) 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% 240 Pu). The system noise base was about 0.2 rad, equivalent to about 1 mg of plutonium

Application technology for optical fiber in nuclear facilities

International Nuclear Information System (INIS)

Lee, Jong Min; Kim, Chul Jung; Lee, Yong Bum; Kim, Woong Ki; Yoon, Tae Seob; Sohn, Surg Won; Kim, Chang Hoi; Hwang, Suk Yong; Baik, Sung Hum; Kwon, Seong Ouk

1987-12-01

Lately, the optical fiber increasingly used in such adverse environments as nuclear power plant, radiation facilities because of their endurant properties against heat, radiation, corrosion, etc. Moreover, the transmission of signal through optical fiber does not induce interference from the electromagnetic wave. Basic theory about the optical fiber technology was studied and the developed techniques for nuclear facilities were reviewed. Since the radiations change the characteristics of the optical fiber, the effects of γ-ray irradiation on single mode and multimode optical fiber were examined. The image transmission system through optical fiber bundle was designed, constructed, and tested. Its software system was also updated. It can be used for remote internal inspection in adverse environment. (Author)

Distributed Fiber Optic Sensor for Early Detection of Rocky Slopes Movements

Science.gov (United States)

Minardo, Aldo; Picarelli, Luciano; Coscetta, Agnese; Zeni, Giovanni; Esposito, Giuseppe; Sacchi, Marco; Matano, Fabio; Caccavale, Mauro; Luigi, Zeni

2014-05-01

Distributed optical fiber sensors have in recent years gained considerable attention in structural and environmental monitoring due to specific advantages that, apart from the classical advantages common to all optical fiber sensors such as immunity to electromagnetic interferences, high sensitivity, small size and possibility to be embedded into the structures, multiplexing and remote interrogation capabilities [1], offer the unique feature of allowing the exploitation of a telecommunication grade optical fiber cable as the sensing element to measure deformation and temperature profiles over very long distances. In particular, distributed optical fiber sensors based on stimulated Brillouin scattering (SBS) through the so-called Brillouin Optical Time Domain Analysis (BOTDA), allow to measure strain and temperature profiles up to tens of kilometers with a strain accuracy of ±10µɛ and a temperature accuracy of ±1°C [2]. They have already been successfully employed in the monitoring of large civil and geotechnical structures such as bridges, tunnels, dams, pipelines allowing to identify and localize any kind of failures that can occur during their construction and operation [3,4]. In this paper we present the application of BOTDA to the monitoring of movements in a rocky slope, showing how the sensing optical fiber cable is able to detect the formation and follow the growth of fractures, and to identify their location along the slope, as well. The experimental results have been achieved on a test field located in the area of Naples (Italy), where a single mode optical fiber sensing cable has been deployed along a yellow tuffs slope, by spot gluing the cable with epoxy adhesive. In order to assess the validity of the proposed approach, a few existing cracks have been artificially enlarged and the magnitude and location of the induced strain peaks have been clearly identified by the sensing device. It should be emphasized that, due to the distributed nature of the

A Fiber Optic Ammonia Sensor Using a Universal pH Indicator

Directory of Open Access Journals (Sweden)

Adolfo J. Rodríguez

2014-02-01

Full Text Available A universal pH indicator is used to fabricate a fiber optic ammonia sensor. The advantage of this pH indicator is that it exhibits sensitivity to ammonia over a broad wavelength range. This provides a differential response, with a valley around 500 nm and a peak around 650 nm, which allows us to perform ratiometric measurements. The ratiometric measurements provide not only an enhanced signal, but can also eliminate any external disturbance due to humidity or temperature fluctuations. In addition, the indicator is embedded in a hydrophobic and gas permeable polyurethane film named Tecoflex®. The film provides additional advantages to the sensor, such as operation in dry environments, efficient transport of the element to be measured to the sensitive area of the sensor, and prevent leakage or detachment of the indicator. The combination of the universal pH indicator and Tecoflex® film provides a reliable and robust fiber optic ammonia sensor.

A Fiber Optic Ammonia Sensor Using a Universal pH Indicator

Science.gov (United States)

Rodríguez, Adolfo J.; Zamarreño, Carlos R.; Matías, Ignacio R.; Arregui, Francisco. J.; Domínguez Cruz, Rene F.; May-Arrioja, Daniel. A.

2014-01-01

A universal pH indicator is used to fabricate a fiber optic ammonia sensor. The advantage of this pH indicator is that it exhibits sensitivity to ammonia over a broad wavelength range. This provides a differential response, with a valley around 500 nm and a peak around 650 nm, which allows us to perform ratiometric measurements. The ratiometric measurements provide not only an enhanced signal, but can also eliminate any external disturbance due to humidity or temperature fluctuations. In addition, the indicator is embedded in a hydrophobic and gas permeable polyurethane film named Tecoflex®. The film provides additional advantages to the sensor, such as operation in dry environments, efficient transport of the element to be measured to the sensitive area of the sensor, and prevent leakage or detachment of the indicator. The combination of the universal pH indicator and Tecoflex® film provides a reliable and robust fiber optic ammonia sensor. PMID:24583969

All-fiber hybrid photon-plasmon circuits: integrating nanowire plasmonics with fiber optics.

Science.gov (United States)

Li, Xiyuan; Li, Wei; Guo, Xin; Lou, Jingyi; Tong, Limin

2013-07-01

We demonstrate all-fiber hybrid photon-plasmon circuits by integrating Ag nanowires with optical fibers. Relying on near-field coupling, we realize a photon-to-plasmon conversion efficiency up to 92% in a fiber-based nanowire plasmonic probe. Around optical communication band, we assemble an all-fiber resonator and a Mach-Zehnder interferometer (MZI) with Q-factor of 6 × 10(6) and extinction ratio up to 30 dB, respectively. Using the MZI, we demonstrate fiber-compatible plasmonic sensing with high sensitivity and low optical power.

Two mode optical fiber in space optics communication

Science.gov (United States)

Hampl, Martin

2017-11-01

In our contribution we propose to use of a two-mode optical fiber as a primary source in a transmitting optical head instead of the laser diode. The distribution of the optical intensity and the complex degree of the coherence on the output aperture of the lens that is irradiated by a step-index weakly guiding optical fiber is investigated. In our treatment we take into account weakly guided modes with polarization corrections to the propagation constant and unified theory of second order coherence and polarization of electromagnetic beams.

Fundamentals of plastic optical fibers

CERN Document Server

Koike, Yasuhiro

2014-01-01

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

Curved Piezoelectric Actuators for Stretching Optical Fibers

Science.gov (United States)

Allison, Sidney G.; Shams, Qamar A.; Fox, Robert L.

2008-01-01

Assemblies containing curved piezoceramic fiber composite actuators have been invented as means of stretching optical fibers by amounts that depend on applied drive voltages. Piezoceramic fiber composite actuators are conventionally manufactured as sheets or ribbons that are flat and flexible, but can be made curved to obtain load-carrying ability and displacement greater than those obtainable from the flat versions. In the primary embodiment of this invention, piezoceramic fibers are oriented parallel to the direction of longitudinal displacement of the actuators so that application of drive voltage causes the actuator to flatten, producing maximum motion. Actuator motion can be transmitted to the optical fiber by use of hinges and clamp blocks. In the original application of this invention, the optical fiber contains a Bragg grating and the purpose of the controlled stretching of the fiber is to tune the grating as part of a small, lightweight, mode-hop-free, rapidly tunable laser for demodulating strain in Bragg-grating strain-measurement optical fibers attached to structures. The invention could also be used to apply controllable tensile force or displacement to an object other than an optical fiber.

Ultra-high Frequency Linear Fiber Optic Systems

CERN Document Server

Lau, Kam Y

2009-01-01

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

Photonics and Fiber Optics Processor Lab

Data.gov (United States)

Federal Laboratory Consortium — The Photonics and Fiber Optics Processor Lab develops, tests and evaluates high speed fiber optic network components as well as network protocols. In addition, this...

Optical fiber cable chemical stripping fixture

Science.gov (United States)

Kolasinski, John R. (Inventor); Coleman, Alexander M. (Inventor)

1995-01-01

An elongated fixture handle member is connected to a fixture body member with both members having interconnecting longitudinal central axial bores for the passage of an optical cable therethrough. The axial bore of the fixture body member, however, terminates in a shoulder stop for the outer end of a jacket of the optical cable covering both an optical fiber and a coating therefor, with an axial bore of reduced diameter continuing from the shoulder stop forward for a predetermined desired length to the outer end of the fixture body member. A subsequent insertion of the fixture body member including the above optical fiber elements into a chemical stripping solution results in a softening of the exposed external coating thereat which permits easy removal thereof from the optical fiber while leaving a desired length coated fiber intact within the fixture body member.

Fiber-optic technology review

International Nuclear Information System (INIS)

Lyons, P.B.

1980-01-01

A history of fiber technology is presented. The advantages of fiber optics are discussed (bandwidth, cost, weight and size, nonmetallic construction and isolation). Some aspects of the disadvantages of fiber systems briefly discussed are fiber and cable availability, fiber components, radiation effects, receivers and transmitters, and material dispersion. Particular emphasis over the next several years will involve development of fibers and systems optimized for use at wavelengths near 1.3 μm and development of wavelengths multiplexers for simultaneous system operation at several wavelengths

Fiber-Optic Pyrometer with Optically Powered Switch for Temperature Measurements.

Science.gov (United States)

Vázquez, Carmen; Pérez-Prieto, Sandra; López-Cardona, Juan D; Tapetado, Alberto; Blanco, Enrique; Moreno-López, Jorge; Montero, David S; Lallana, Pedro C

2018-02-06

We report the experimental results on a new infrared fiber-optic pyrometer for very localized and high-speed temperature measurements ranging from 170 to 530 °C using low-noise photodetectors and high-gain transimpedance amplifiers with a single gain mode in the whole temperature range. We also report a shutter based on an optical fiber switch which is optically powered to provide a reference signal in an optical fiber pyrometer measuring from 200 to 550 °C. The tests show the potential of remotely powering via optical means a 300 mW power-hungry optical switch at a distance of 100 m, avoiding any electromagnetic interference close to the measuring point.

Fiber-Optic Pyrometer with Optically Powered Switch for Temperature Measurements

Directory of Open Access Journals (Sweden)

Carmen Vázquez

2018-02-01

Full Text Available We report the experimental results on a new infrared fiber-optic pyrometer for very localized and high-speed temperature measurements ranging from 170 to 530 °C using low-noise photodetectors and high-gain transimpedance amplifiers with a single gain mode in the whole temperature range. We also report a shutter based on an optical fiber switch which is optically powered to provide a reference signal in an optical fiber pyrometer measuring from 200 to 550 °C. The tests show the potential of remotely powering via optical means a 300 mW power-hungry optical switch at a distance of 100 m, avoiding any electromagnetic interference close to the measuring point.

Experimental study on distributed optical fiber-based approach monitoring saturation line in levee engineering

Science.gov (United States)

Su, Huaizhi; Li, Hao; Kang, Yeyuan; Wen, Zhiping

2018-02-01

Seepage is one of key factors which affect the levee engineering safety. The seepage danger without timely detection and rapid response may likely lead to severe accidents such as seepage failure, slope instability, and even levee break. More than 90 percent of levee break events are caused by the seepage. It is very important for seepage behavior identification to determine accurately saturation line in levee engineering. Furthermore, the location of saturation line has a major impact on slope stability in levee engineering. Considering the structure characteristics and service condition of levee engineering, the distributed optical fiber sensing technology is introduced to implement the real-time observation of saturation line in levee engineering. The distributed optical fiber temperature sensor system (DTS)-based monitoring principle of saturation line in levee engineering is investigated. An experimental platform, which consists of DTS, heating system, water-supply system, auxiliary analysis system and levee model, is designed and constructed. The monitoring experiment of saturation line in levee model is implemented on this platform. According to the experimental results, the numerical relationship between moisture content and thermal conductivity in porous medium is identified. A line heat source-based distributed optical fiber method obtaining the thermal conductivity in porous medium is developed. A DTS-based approach is proposed to monitor the saturation line in levee engineering. The embedment pattern of optical fiber for monitoring saturation line is presented.

Embedding piezoresistive pressure sensors to obtain online pressure profiles inside fiber composite laminates.

Science.gov (United States)

Moghaddam, Maryam Kahali; Breede, Arne; Brauner, Christian; Lang, Walter

2015-03-27

The production of large and complex parts using fiber composite materials is costly due to the frequent formation of voids, porosity and waste products. By embedding different types of sensors and monitoring the process in real time, the amount of wastage can be significantly reduced. This work focuses on developing a knowledge-based method to improve and ensure complete impregnation of the fibers before initiation of the resin cure. Piezoresistive and capacitive pressure sensors were embedded in fiber composite laminates to measure the real-time the pressure values inside the laminate. A change of pressure indicates resin infusion. The sensors were placed in the laminate and the resin was infused by vacuum. The embedded piezoresistive pressure sensors were able to track the vacuum pressure in the fiber composite laminate setup, as well as the arrival of the resin at the sensor. The pressure increase due to closing the resin inlet was also measured. In contrast, the capacitive type of sensor was found to be inappropriate for measuring these quantities. The following study demonstrates real-time monitoring of pressure changes inside the fiber composite laminate, which validate the use of Darcy's law in porous media to control the resin flow during infusion.

Multi-sample immunoassay inside optical fiber capillary enabled by evanescent wave detection

Directory of Open Access Journals (Sweden)

Chun-Wei Wang

2016-03-01

Full Text Available A novel evanescent wave-based (EW microfluidic capillary fiber-optic biosensor (MCFOB has been developed using capillaries as a transducer embedded in a multichannel device to enhance the collection efficiency of the fluorescence signal. The capillary serves dual roles as a waveguide and a container, enabling more straightforward, consistent, and compact biosensor packaging compared to conventional optical fiber biosensors and microfluidic systems. In order to detect multiple samples in one device, the biosensor incorporates a polydimethysiloxane (PDMS multi-channel device, which also serves as cladding for the biosensor. In addition, this biosensor only consumes 10 μl of a sample and does not require hydrofluoric acid etching in the fabrication process. The orientation for signal collection is optimized by comparing the lateral and normal signal directions for detected glyceraldehyde 3-phosphate dehydrogenase (GAPDH. C-reactive protein (CRP is used to validate the MCFOB, and the limit of detection (LOD for CRP in the MCFOB is 1.94 ng/ml (74 pM. Moreover, the real-time measurement is demonstrated to verify that the evanescent wave is the only exciting light source in the MCFOB, which gives the potential for real-time measurement applications. Keywords: C-reactive protein, Capillary, Fiber-optic, Microfluidic, Evanescent wave, Immunoassay

Qualification of a truly distributed fiber optic technique for strain and temperature measurements in concrete structures

Science.gov (United States)

Henault, J. M.; Salin, J.; Moreau, G.; Delepine-Lesoille, S.; Bertand, J.; Taillade, F.; Quiertant, M.; Benzarti, K.

2011-04-01

Structural health monitoring is a key factor in life cycle management of infrastructures. Truly distributed fiber optic sensors are able to provide relevant information on large structures, such as nuclear power plants or nuclear waste disposal facilities. The sensing chain includes an optoelectronic unit and a sensing cable made of one or more optical fibers. A new instrument based on Optical Frequency Domain Reflectometry (OFDR), enables to perform temperature and strain measurements with a centimeter scale spatial resolution over hundred of meters and with a level of precision equal to 1 μ strain and 0.1 °C. Several sensing cables are designed with different materials targeting to last for decades, either embedded in the concrete or attached to the surface of the structure. They must ensure an optimal transfer of temperature and strain from the concrete matrix to the optical fiber. Based on the European guide FD CEN/TR 14748 "Non-destructive testing - Methodology for qualification of non-destructive tests", a qualification method was developed. Tests were carried out using various sensing cables embedded in the volume or fixed to the surface of plain concrete specimens and representative-scale reinforced concrete structural elements. Measurements were performed with an OFDR instrument, while mechanical solicitations were imposed to the concrete element. Preliminary experiments seem very promising since measurements performed with distributed sensing systems are found comparable to values obtained with conventional sensors used in civil engineering and with the Strength of Materials Modelling. Moreover, the distributed sensing system makes it possible to detect and localize cracks appearing in concrete during the mechanical loading.

Optofluidic in-fiber interferometer based on hollow optical fiber with two cores.

Science.gov (United States)

Yuan, Tingting; Yang, Xinghua; Liu, Zhihai; Yang, Jun; Li, Song; Kong, Depeng; Qi, Xiuxiu; Yu, Wenting; Long, Qunlong; Yuan, Libo

2017-07-24

We demonstrate a novel integrated optical fiber interferometer for in-fiber optofluidic detection. It is composed of a specially designed hollow optical fiber with a micro-channel and two cores. One core on the inner surface of the micro-channel is served as sensing arm and the other core in the annular cladding is served as reference arm. Fusion-and-tapering method is employed to couple light from a single mode fiber to the hollow optical fiber in this device. Sampling is realized by side opening a microhole on the surface of the hollow optical fiber. Under differential pressure between the end of the hollow fiber and the microhole, the liquids can form steady microflows in the micro-channel. Simultaneously, the interference spectrum of the interferometer device shifts with the variation of the concentration of the microfluid in the channel. The optofluidic in-fiber interferometer has a sensitivity of refractive index around 2508 nm/RIU for NaCl. For medicine concentration detection, its sensitivity is 0.076 nm/mmolL -1 for ascorbic acid. Significantly, this work presents a compact microfluidic in-fiber interferometer with a micro-channel which can be integrated with chip devices without spatial optical coupling and without complex manufacturing procedure of the waveguide on the chips.

Optical Fiber Sensor Based on Localized Surface Plasmon Resonance Using Silver Nanoparticles Photodeposited on the Optical Fiber End

Directory of Open Access Journals (Sweden)

J. Gabriel Ortega-Mendoza

2014-10-01

Full Text Available This paper reports the implementation of an optical fiber sensor to measure the refractive index in aqueous media based on localized surface plasmon resonance (LSPR. We have used a novel technique known as photodeposition to immobilize silver nanoparticles on the optical fiber end. This technique has a simple instrumentation, involves laser light via an optical fiber and silver nanoparticles suspended in an aqueous medium. The optical sensor was assembled using a tungsten lamp as white light, a spectrometer, and an optical fiber with silver nanoparticles. The response of this sensor is such that the LSPR peak wavelength is linearly shifted to longer wavelengths as the refractive index is increased, showing a sensitivity of 67.6 nm/RIU. Experimental results are presented.

Fiber Optic Augmented Reality System (FOARS)

Data.gov (United States)

National Aeronautics and Space Administration — Innovation: Fiber Optics Augmented Reality System. This system in form of a mobile app interacts real time with the actual FOSS(Fiber Optics Sensing System) data and...

Ultra-high Frequency Linear Fiber Optic Systems

CERN Document Server

Lau, Kam

2011-01-01

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

Design of fiber optic probes for laser light scattering

Science.gov (United States)

Dhadwal, Harbans S.; Chu, Benjamin

1989-01-01

A quantitative analysis is presented of the role of optical fibers in laser light scattering. Design of a general fiber optic/microlens probe by means of ray tracing is described. Several different geometries employing an optical fiber of the type used in lightwave communications and a graded index microlens are considered. Experimental results using a nonimaging fiber optic detector probe show that due to geometrical limitations of single mode fibers, a probe using a multimode optical fiber has better performance, for both static and dynamic measurements of the scattered light intensity, compared with a probe using a single mode fiber. Fiber optic detector probes are shown to be more efficient at data collection when compared with conventional approaches to measurements of the scattered laser light. Integration of fiber optic detector probes into a fiber optic spectrometer offers considerable miniaturization of conventional light scattering spectrometers, which can be made arbitrarily small. In addition static and dynamic measurements of scattered light can be made within the scattering cell and consequently very close to the scattering center.

Fiber-Optic Vibration Sensor Based on Multimode Fiber

Directory of Open Access Journals (Sweden)

I. Lujo

2008-06-01

Full Text Available The purpose of this paper is to present a fiberoptic vibration sensor based on the monitoring of the mode distribution in a multimode optical fiber. Detection of vibrations and their parameters is possible through observation of the output speckle pattern from the multimode optical fiber. A working experimental model has been built in which all used components are widely available and cheap: a CCD camera (a simple web-cam, a multimode laser in visible range as a light source, a length of multimode optical fiber, and a computer for signal processing. Measurements have shown good agreement with the actual frequency of vibrations, and promising results were achieved with the amplitude measurements although they require some adaptation of the experimental model. Proposed sensor is cheap and lightweight and therefore presents an interesting alternative for monitoring large smart structures.

Performance of Integrated Fiber Optic, Piezoelectric, and Shape Memory Alloy Actuators/Sensors in Thermoset Composites

Science.gov (United States)

Trottier, C. Michael

1996-01-01

Recently, scientists and engineers have investigated the advantages of smart materials and structures by including actuators in material systems for controlling and altering the response of structural environments. Applications of these materials systems include vibration suppression/isolation, precision positioning, damage detection and tunable devices. Some of the embedded materials being investigated for accomplishing these tasks include piezoelectric ceramics, shape memory alloys, and fiber optics. These materials have some benefits and some shortcomings; each is being studied for use in active material design in the SPICES (Synthesis and Processing of Intelligent Cost Effective Structures) Consortium. The focus of this paper concerns the manufacturing aspects of smart structures by incorporating piezoelectric ceramics, shape memory alloys and fiber optics in a reinforced thermoset matrix via resin transfer molding (RTM).

Cladding modes of optical fibers: properties and applications

International Nuclear Information System (INIS)

Ivanov, Oleg V; Nikitov, Sergei A; Gulyaev, Yurii V

2006-01-01

One of the new methods of fiber optics uses cladding modes for controlling propagation of radiation in optical fibers. This paper reviews the results of studies on the propagation, excitation, and interaction of cladding modes in optical fibers. The resonance between core and cladding modes excited by means of fiber Bragg gratings, including tilted ones, is analyzed. Propagation of cladding modes in microstructured fibers is considered. The most frequently used method of exciting cladding modes is described, based on the application of long-period fiber gratings. Examples are presented of long-period gratings used as sensors and gain equalizers for fiber amplifiers, as well as devices for coupling light into and out of optical fibers. (instruments and methods of investigation)

Optical fiber strain sensor using fiber resonator based on frequency comb Vernier spectroscopy

DEFF Research Database (Denmark)

Zhang, Liang; Lu, Ping; Chen, Li

2012-01-01

A novel (to our best knowledge) optical fiber strain sensor using a fiber ring resonator based on frequency comb Vernier spectroscopy is proposed and demonstrated. A passively mode-locked optical fiber laser is employed to generate a phased-locked frequency comb. Strain applied to the optical fib...

Optical fiber meta-tips

Science.gov (United States)

Principe, Maria; Micco, Alberto; Crescitelli, Alessio; Castaldi, Giuseppe; Consales, Marco; Esposito, Emanuela; La Ferrara, Vera; Galdi, Vincenzo; Cusano, Andrea

2016-04-01

We report on the first example of a "meta-tip" configuration that integrates a metasurface on the tip of an optical fiber. Our proposed design is based on an inverted-Babinet plasmonic metasurface obtained by patterning (via focused ion beam) a thin gold film deposited on the tip of an optical fiber, so as to realize an array of rectangular aperture nanoantennas with spatially modulated sizes. By properly tuning the resonances of the aperture nanoantennas, abrupt variations can be impressed in the field wavefront and polarization. We fabricated and characterized several proof-of-principle prototypes operating an near-infrared wavelengths, and implementing the beam-steering (with various angles) of the cross-polarized component, as well as the excitation of surface waves. Our results pave the way to the integration of the exceptional field-manipulation capabilities enabled by metasurfaces with the versatility and ubiquity of fiber-optics technological platforms.

Superlattice Microstructured Optical Fiber

Science.gov (United States)

Tse, Ming-Leung Vincent; Liu, Zhengyong; Cho, Lok-Hin; Lu, Chao; Wai, Ping-Kong Alex; Tam, Hwa-Yaw

2014-01-01

A generic three-stage stack-and-draw method is demonstrated for the fabrication of complex-microstructured optical fibers. We report the fabrication and characterization of a silica superlattice microstructured fiber with more than 800 rhomboidally arranged air-holes. A polarization-maintaining fiber with a birefringence of 8.5 × 10−4 is demonstrated. The birefringent property of the fiber is found to be highly insensitive to external environmental effects, such as pressure. PMID:28788693

Fiber optic pressure sensors for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

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

1995-04-01

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

Fiber optic pressure sensors for nuclear power plants

International Nuclear Information System (INIS)

Hashemian, H.M.; Black, C.L.

1995-01-01

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

Fiber optic fluid detector

Science.gov (United States)

Angel, S.M.

1987-02-27

Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

Optical fibers and their applications for radiation measurements

International Nuclear Information System (INIS)

Kakuta, Tsunemi

1998-01-01

When optical fibers are used in a strong radiation field, it is necessary to increase the radiation-resistant capacity. Aiming at the improvement of such property, the characteristics of recent optical fibers made from quartz-glass were reviewed and the newly developed techniques for radiation measurement using those fibers were summarized in this report. Since optical fibers became able to use in the levels near the core conditions, their applications have started in various fields of technologies related to radiation. By combining the optical fibers and a small sensor, it became possible to act as 'Key Component' for measuring wide range radioactivity from a trace activity to a strong radiation field in the reactor core. Presently, the fibers are utilized for investigation of the optical mechanisms related in radiation, evaluation of their validities so on. Further, the optical fibers are expected to utilize in a multi-parametric measuring system which allows to concomitantly determine the radiation, temperature, pressure, flow amount etc. as an incore monitor. (M.N.)

Optical fibers and their applications for radiation measurements

Energy Technology Data Exchange (ETDEWEB)

Kakuta, Tsunemi [Japan Atomic Energy Research Inst., Tokyo (Japan)

1998-07-01

When optical fibers are used in a strong radiation field, it is necessary to increase the radiation-resistant capacity. Aiming at the improvement of such property, the characteristics of recent optical fibers made from quartz-glass were reviewed and the newly developed techniques for radiation measurement using those fibers were summarized in this report. Since optical fibers became able to use in the levels near the core conditions, their applications have started in various fields of technologies related to radiation. By combining the optical fibers and a small sensor, it became possible to act as `Key Component` for measuring wide range radioactivity from a trace activity to a strong radiation field in the reactor core. Presently, the fibers are utilized for investigation of the optical mechanisms related in radiation, evaluation of their validities so on. Further, the optical fibers are expected to utilize in a multi-parametric measuring system which allows to concomitantly determine the radiation, temperature, pressure, flow amount etc. as an incore monitor. (M.N.)

Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

Czech Academy of Sciences Publication Activity Database

Pospíšilová, M.; Kuncová, Gabriela; Trögl, J.

2015-01-01

Roč. 15, č. 10 (2015), s. 25208-25259 ISSN 1424-8220 Institutional support: RVO:67985858 Keywords : fiber-optic sensor * chemical sensors * enzymatic sensor Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 2.033, year: 2015

Portable fiber-optic taper coupled optical microscopy platform

Science.gov (United States)

Wang, Weiming; Yu, Yan; Huang, Hui; Ou, Jinping

2017-04-01

The optical fiber taper coupled with CMOS has advantages of high sensitivity, compact structure and low distortion in the imaging platform. So it is widely used in low light, high speed and X-ray imaging systems. In the meanwhile, the peculiarity of the coupled structure can meet the needs of the demand in microscopy imaging. Toward this end, we developed a microscopic imaging platform based on the coupling of cellphone camera module and fiber optic taper for the measurement of the human blood samples and ascaris lumbricoides. The platform, weighing 70 grams, is based on the existing camera module of the smartphone and a fiber-optic array which providing a magnification factor of 6x.The top facet of the taper, on which samples are placed, serves as an irregular sampling grid for contact imaging. The magnified images of the sample, located on the bottom facet of the fiber, are then projected onto the CMOS sensor. This paper introduces the portable medical imaging system based on the optical fiber coupling with CMOS, and theoretically analyzes the feasibility of the system. The image data and process results either can be stored on the memory or transmitted to the remote medical institutions for the telemedicine. We validate the performance of this cell-phone based microscopy platform using human blood samples and test target, achieving comparable results to a standard bench-top microscope.

Essentials of modern optical fiber communication

CERN Document Server

Noé, Reinhold

2016-01-01

This is a concise introduction into optical fiber communication. It covers important aspects from the physics of optical wave propagation and amplification to the essentials of modulation formats and receivers. The combination of a solid coverage of necessary fundamental theory with an in-depth discussion of recent relevant research results enables the reader to design modern optical fiber communication systems. The book serves both graduate students and professionals. It includes many worked examples with solutions for lecturers. For the second edition, Reinhold Noé made many changes and additions throughout the text so that this concise book presents the essentials of optical fiber communication in an easy readable and understandable way.

Comparison of Distributed Acoustic Sensing (DAS) from Fiber-Optic Cable to Three Component Geophones in an Underground Mine

Science.gov (United States)

Speece, M. A.; Nesladek, N. J.; Kammerer, C.; Maclaughlin, M.; Wang, H. F.; Lord, N. E.

2017-12-01

fiber-optic cables that were pressed against the rock face with a spacer outperformed fiber-optic cables that were fully embedded within the grout filling the inside of the borehole.

Integrated Optical Circuit Engineering For Optical Fiber Gyrocopes

Science.gov (United States)

Bristow, Julian P.; We, Albert C.; Keur, M.; Lukas, Greg; Ott, Daniel M...; Sriram, S.

1988-03-01

Fiber optic gyroscopes are of interest for low-cost, high performance rotation sensors. Integrated optical implementations of the processing optics offer the hope of mass-production, and associated cost reductions. The development of a suitable integrated optical system has been reported by other authors at a wavelength of 850nm [1]. Despite strong technical advantages at 1.3μm wavelength [2], no results have yet appeared. This wavelength is preferred for telecommunications applications applications, thus significantly reduced fiber costs may be realized. Lithium niobate is relatively immune from the photorefractive effect at this wavelength, whereas it is not at at 850nm [3].

High-temperature fiber optic pressure sensor

Science.gov (United States)

Berthold, J. W.

1984-01-01

Attention is given to a program to develop fiber optic methods to measure diaphragm deflection. The end application is intended for pressure transducers capable of operating to 540 C. In this paper are reported the results of a laboratory study to characterize the performance of the fiber-optic microbend sensor. The data presented include sensitivity and spring constant. The advantages and limitations of the microbend sensor for static pressure measurement applications are described. A proposed design is presented for a 540 C pressure transducer using the fiber optic microbend sensor.

Fiber optic communications fundamentals and applications

CERN Document Server

Kumar, Shiva

2014-01-01

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

355-nm hypersensitization of optical fibers

NARCIS (Netherlands)

Canagasabey, A.; Canning, J.; Groothoff, N.

2003-01-01

A study is presented on 355-nm hypersensitization of optical fibers. It is found that the intrinsic 244-nm photosensitivity of boron-codoped germanosilicate optical fibers is enhanced by 355-nm hypersensitization. Hypersensitization through standard polymer coating is also demonstrated.

All-optical, thermo-optical path length modulation based on the vanadium-doped fibers.

Science.gov (United States)

Matjasec, Ziga; Campelj, Stanislav; Donlagic, Denis

2013-05-20

This paper presents an all-fiber, fully-optically controlled, optical-path length modulator based on highly absorbing optical fiber. The modulator utilizes a high-power 980 nm pump diode and a short section of vanadium-co-doped single mode fiber that is heated through absorption and a non-radiative relaxation process. The achievable path length modulation range primarily depends on the pump's power and the convective heat-transfer coefficient of the surrounding gas, while the time response primarily depends on the heated fiber's diameter. An absolute optical length change in excess of 500 µm and a time-constant as short as 11 ms, were demonstrated experimentally. The all-fiber design allows for an electrically-passive and remote operation of the modulator. The presented modulator could find use within various fiber-optics systems that require optical (remote) path length control or modulation.

Optical fiber Cherenkov detector for beam current monitoring

International Nuclear Information System (INIS)

Pishchulin, I.V.; Solov'ev, N.G.; Romashkin, O.B.

1991-01-01

The results obtained in calculation of an optical fiber Cherenkov detector for accelerated beam current monitoring are presented. The technique of beam parameters monitoring is based on Cherenkov radiation excitation by accelerated electrons in the optical fiber. The formulas for calculations of optical power and time dependence of Cherenkov radiation pulse are given. The detector sensitivity and time resolution dependence on the fiber material characteristics are investigated. Parameters of a 10μm one-mode quartz optical fiber detector for the free electron laser photoinjector are calculated. The structure of a monitoring system with the optical fiber Cherenkov detector is considered. Possible applications of this technique are discussed and some recommendations are given

Optical fiber powered pressure sensor

International Nuclear Information System (INIS)

Schweizer, P.; Neveux, L.; Ostrowsky, D.B.

1987-01-01

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

Quartz fiber calorimeter

International Nuclear Information System (INIS)

Akchurin, N.; Doulas, S.; Ganel, O.; Gershtein, Y.; Gavrilov, V.; Kolosov, V.; Kuleshov, S.; Litvinsev, D.; Merlo, J.-P.; Onel, Y.; Osborne, D.; Rosowsky, A.; Stolin, V.; Sulak, L.; Sullivan, J.; Ulyanov, A.; Wigmans, R.; Winn, D.

1996-01-01

A calorimeter with optical quartz fibers embedded into an absorber matrix was proposed for the small angle region of the CMS detector at LHC (CERN). This type of calorimeter is expected to be radiation hard and to produce extremely fast signal. Some results from beam tests of the quartz fiber calorimeter prototype are presented. (orig.)

Direct writing of fiber optic components in photonic crystal fibers and other specialty fibers

Science.gov (United States)

Fernandes, Luis Andre; Sezerman, Omur; Best, Garland; Ng, Mi Li; Kane, Saidou

2016-04-01

Femtosecond direct laser writing has recently shown great potential for the fabrication of complex integrated devices in the cladding of optical fibers. Such devices have the advantage of requiring no bulk optical components and no breaks in the fiber path, thus reducing the need for complicated alignment, eliminating contamination, and increasing stability. This technology has already found applications using combinations of Bragg gratings, interferometers, and couplers for the fabrication of optical filters, sensors, and power monitors. The femtosecond laser writing method produces a local modification of refractive index through non-linear absorption of the ultrafast laser pulses inside the dielectric material of both the core and cladding of the fiber. However, fiber geometries that incorporate air or hollow structures, such as photonic crystal fibers (PCFs), still present a challenge since the index modification regions created by the writing process cannot be generated in the hollow regions of the fiber. In this work, the femtosecond laser method is used together with a pre-modification method that consists of partially collapsing the hollow holes using an electrical arc discharge. The partial collapse of the photonic band gap structure provides a path for femtosecond laser written waveguides to couple light from the core to the edge of the fiber for in-line power monitoring. This novel approach is expected to have applications in other specialty fibers such as suspended core fibers and can open the way for the integration of complex devices and facilitate miniaturization of optical circuits to take advantage of the particular characteristics of the PCFs.

Microstructured optical fibers - Fundamentals and applications

DEFF Research Database (Denmark)

Lægsgaard, Jesper; Bjarklev, Anders Overgaard

2006-01-01

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

Polymer optical fiber with Rhodamine doped cladding for fiber light systems

Energy Technology Data Exchange (ETDEWEB)

Narro-García, R., E-mail: roberto.narro@gmail.com [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Quintero-Torres, R. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Domínguez-Juárez, J.L. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Cátedras CONACyT, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico); Ocampo, M.A. [Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Querétaro 76230 (Mexico)

2016-01-15

Both preform and polymer optical fiber with a Poly(methyl methacrylate) core and THV–Rhodamine 6G cladding were characterized. UV–vis absorbance, photoluminescence spectra and lifetime of the preform were measured. Axial and lateral photoluminescence spectra of the polymer optical fiber were studied under 404 nm excitation in order to study the illumination performance of the fiber. It was observed that the peak wavelength from the fiber photoluminescence spectra is higher than the peak wavelength from the fiber preform and that the peak wavelength from the fiber photoluminescence spectra is red shifted with the fiber length in the case of axial emission. The obtained results suggest the influence of self-absorption on the photoluminescence shape. Strong lateral emission along the fiber was observed with the naked eyes in all the cases. The lateral photoluminescence spectra show that the lateral emission is a combination between the pump laser and the Rh6G molecule photoluminescence. The results suggest that this polymer optical fiber could be a potential candidate for the development of fiber lighting systems. - Highlights: • Axial and lateral emission along the fiber was studied. • Self-absorption effect was confirmed in the case of axial photoluminescence. • The lateral emission is a combination between the laser and the RhG6 emission. • This fiber could be a potential candidate for the development of lighting systems.

Instrumentation by distributed optical fiber sensors of a new ballastless track structure

Science.gov (United States)

Chapeleau, Xavier; Cottineau, Louis-Marie; Sedran, Thierry; Gueguen, Ivan; Cailliau, Joël

2013-04-01

While relatively expensive to build, ballastless track structures are presently seen as an attractive alternative to conventional ballast. With its service life of at least 60 years, they require little maintenance and hence they offer great availability. Other reasons for using ballastless tracks instead of ballasted tracks are the lack of suitable ballast material and the need of less noise and vibration for high-speed, in particularly. A new ballastless track structure has been designed to be circulated up to 300km/h, with a target life of 100 years. It is an interoperable way on concrete slabs that are cast-in-place and slip formed. This structure has been built and tested at the scale one in our laboratory. Indeed, ten millions cyclic loads were applied at 2.5Hz to evaluate the fatigue behaviour under selected mechanical and thermal conditions. To monitor the thermo-mechanical behavior of this new structure and to verify the numerical simulations used for its design, a lot of sensors have been embedded. In particularly, we have tested an optical fiber as distributed sensors to measure strain distribution in the railway model. This sensor can also be used to detect, localize and monitor cracks in concrete slabs. The optical fiber sensing technique ("Rayleigh technique") used in this experimentation has a centimetric spatial resolution which allows to measure complex strain profiles unlike electrical strain gauges which only give local information. Firstly, optical cables used as sensors have been successfully embedded and attached to the reinforcing steel bars in the structure. We have noted that they are resistant enough to resist concrete pouring and working activities. Secondly, strains measured by conventional strain gauges has confirmed the quality of the strain profiles measurements obtained by optical fiber sensors. Moreover, we have found a good agreement between experimental profiles measurements and those obtained by numerical simulations. Early

Fiber optic applications in nuclear power plants

International Nuclear Information System (INIS)

Collette, P.; Kwapien, D.

1984-01-01

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

Near-field scanning optical microscopy using polymethylmethacrylate optical fiber probes

International Nuclear Information System (INIS)

Chibani, H.; Dukenbayev, K.; Mensi, M.; Sekatskii, S.K.; Dietler, G.

2010-01-01

We report the first use of polymethylmethacrylate (PMMA) optical fiber-made probes for scanning near-field optical microscopy (SNOM). The sharp tips were prepared by chemical etching of the fibers in ethyl acetate, and the probes were prepared by proper gluing of sharpened fibers onto the tuning fork in the conditions of the double resonance (working frequency of a tuning fork coincides with the resonance frequency of dithering of the free-standing part of the fiber) reported earlier for the case of glass fibers. Quality factors of the probes in the range 2000-6000 were obtained, which enables the realization of an excellent topographical resolution including state-of-art imaging of single DNA molecules. Near-field optical performance of the microscope is illustrated by the Photon Scanning Tunneling Microscope images of fluorescent beads with a diameter of 100 nm. The preparation of these plastic fiber probes proved to be easy, needs no hazardous material and/or procedures, and typical lifetime of a probe essentially exceeds that characteristic for the glass fiber probe.

Energy in elastic fiber embedded in elastic matrix containing incident SH wave

Science.gov (United States)

Williams, James H., Jr.; Nagem, Raymond J.

1989-01-01

A single elastic fiber embedded in an infinite elastic matrix is considered. An incident plane SH wave is assumed in the infinite matrix, and an expression is derived for the total energy in the fiber due to the incident SH wave. A nondimensional form of the fiber energy is plotted as a function of the nondimensional wavenumber of the SH wave. It is shown that the fiber energy attains maximum values at specific values of the wavenumber of the incident wave. The results obtained here are interpreted in the context of phenomena observed in acousto-ultrasonic experiments on fiber reinforced composite materials.

Environmental performance of an elliptical core polarization maintaining optical fiber for fiber optic gyro applications

Science.gov (United States)

Martinelli, Vincent P.; Squires, Emily M.; Watkins, James J.

1994-03-01

Corning has introduced a new polarization-maintaining optical fiber to satisfy customer requirements for a range of commercial and military FOG applications. This fiber has an elliptical core, matched-clad design, and is intended for operation in the 780 to 850 nm wavelength region. The fiber has a beat length less than 1.5 mm, attenuation rate less than 10 dB/km, and a typical coiled h-parameter less than 1.5 X 10-4 m-1 in the designated operating wavelength range. It has a cladding diameter of 80 micrometers and a coating diameter of 185 micrometers . The coating is an acrylate system, similar to that used in telecommunications optical fibers. We report on the performance of this elliptical core fiber for a variety of environmental exposures representative of an automotive application.

Engineering surface plasmon based fiber-optic sensors

International Nuclear Information System (INIS)

Dhawan, Anuj; Muth, John F.

2008-01-01

Ordered arrays of nanoholes with subwavelength diameters, and submicron array periodicity were fabricated on the tips of gold-coated optical fibers using focused ion beam (FIB) milling. This provided a convenient platform for evaluating extraordinary transmission of light through subwavelength apertures and allowed the implementation of nanostructures for surface plasmon engineered sensors. The fabrication procedure was straightforward and implemented on single mode and multimode optical fibers as well as etched and tapered fiber tips. Control of the periodicity and spacing of the nanoholes allowed the wavelength of operation to be tailored. Large changes in optical transmission were observed at the designed wavelengths, depending on the surrounding refractive index, allowing the devices to be used as fiber-optic sensors

Engineering surface plasmon based fiber-optic sensors

Energy Technology Data Exchange (ETDEWEB)

Dhawan, Anuj [Department of Electrical and Computer Engineering, NC State University, Raleigh, NC 27606 (United States); Muth, John F. [Department of Electrical and Computer Engineering, NC State University, Raleigh, NC 27606 (United States)], E-mail: muth@unity.ncsu.edu

2008-04-15

Ordered arrays of nanoholes with subwavelength diameters, and submicron array periodicity were fabricated on the tips of gold-coated optical fibers using focused ion beam (FIB) milling. This provided a convenient platform for evaluating extraordinary transmission of light through subwavelength apertures and allowed the implementation of nanostructures for surface plasmon engineered sensors. The fabrication procedure was straightforward and implemented on single mode and multimode optical fibers as well as etched and tapered fiber tips. Control of the periodicity and spacing of the nanoholes allowed the wavelength of operation to be tailored. Large changes in optical transmission were observed at the designed wavelengths, depending on the surrounding refractive index, allowing the devices to be used as fiber-optic sensors.

Computational imaging through a fiber-optic bundle

Science.gov (United States)

Lodhi, Muhammad A.; Dumas, John Paul; Pierce, Mark C.; Bajwa, Waheed U.

2017-05-01

Compressive sensing (CS) has proven to be a viable method for reconstructing high-resolution signals using low-resolution measurements. Integrating CS principles into an optical system allows for higher-resolution imaging using lower-resolution sensor arrays. In contrast to prior works on CS-based imaging, our focus in this paper is on imaging through fiber-optic bundles, in which manufacturing constraints limit individual fiber spacing to around 2 μm. This limitation essentially renders fiber-optic bundles as low-resolution sensors with relatively few resolvable points per unit area. These fiber bundles are often used in minimally invasive medical instruments for viewing tissue at macro and microscopic levels. While the compact nature and flexibility of fiber bundles allow for excellent tissue access in-vivo, imaging through fiber bundles does not provide the fine details of tissue features that is demanded in some medical situations. Our hypothesis is that adapting existing CS principles to fiber bundle-based optical systems will overcome the resolution limitation inherent in fiber-bundle imaging. In a previous paper we examined the practical challenges involved in implementing a highly parallel version of the single-pixel camera while focusing on synthetic objects. This paper extends the same architecture for fiber-bundle imaging under incoherent illumination and addresses some practical issues associated with imaging physical objects. Additionally, we model the optical non-idealities in the system to get lower modelling errors.

Optic Fiber Sensing IOT Technology and Application Research

Directory of Open Access Journals (Sweden)

Wenjuan Zeng

2014-10-01

Full Text Available The growth of the Internet of Things (IOT industry has become a new mark of the communication domain. As the development of the technology of the IOT and the fiber-optical sensor, the combination of the both is a big question to be discussed, and the fiber-optical IOT also has a good development prospect. This article first introduces IOT’s current status, the key technology, the theoretical frame and the applications. Then, it discusses the classification of the optical fiber sensor as well as the development and its application’s situation. Lastly, it puts the optical fiber sensing technology into the IOT, and introduces a specific application which is used in the mine safety based on the fiber-optical IOT.

Monitoring techniques for the manufacture of tapered optical fibers.

Science.gov (United States)

Mullaney, Kevin; Correia, Ricardo; Staines, Stephen E; James, Stephen W; Tatam, Ralph P

2015-10-01

The use of a range of optical techniques to monitor the process of fabricating optical fiber tapers is investigated. Thermal imaging was used to optimize the alignment of the optical system; the transmission spectrum of the fiber was monitored to confirm that the tapers had the required optical properties and the strain induced in the fiber during tapering was monitored using in-line optical fiber Bragg gratings. Tapers were fabricated with diameters down to 5 μm and with waist lengths of 20 mm using single-mode SMF-28 fiber.

A novel thermoset polymer optical fiber

NARCIS (Netherlands)

Flipsen, T.A C; Steendam, R; Pennings, A.J; Hadziioannou, G

Polymer optical fibers are being investigated with a view to overcoming some of the disadvantages of glass optical fibers in communications applications. Dense cross-linked polymers, such as the polyisocyanurate discussed here (see figure), have been found to be superior in some respects to the

Dynamic temperature measurements with embedded optical sensors.

Energy Technology Data Exchange (ETDEWEB)

Dolan, Daniel H.,; Seagle, Christopher T; Ao, Tommy

2013-10-01

This report summarizes LDRD project number 151365, \\Dynamic Temperature Measurements with Embedded Optical Sensors". The purpose of this project was to develop an optical sensor capable of detecting modest temperature states (<1000 K) with nanosecond time resolution, a recurring diagnostic need in dynamic compression experiments at the Sandia Z machine. Gold sensors were selected because the visible re ectance spectrum of gold varies strongly with temperature. A variety of static and dynamic measurements were performed to assess re ectance changes at di erent temperatures and pressures. Using a minimal optical model for gold, a plausible connection between static calibrations and dynamic measurements was found. With re nements to the model and diagnostic upgrades, embedded gold sensors seem capable of detecting minor (<50 K) temperature changes under dynamic compression.

Dispersion properties of plasma cladded annular optical fiber

Science.gov (United States)

KianiMajd, M.; Hasanbeigi, A.; Mehdian, H.; Hajisharifi, K.

2018-05-01

One of the considerable problems in a conventional image transferring fiber optic system is the two-fold coupling of propagating hybrid modes. In this paper, using a simple and practical analytical approach based on exact modal vectorial analysis together with Maxwell's equations, we show that applying plasma as a cladding medium of an annular optical fiber can remove this defect of conventional fiber optic automatically without any external instrument as the polarization beam splitter. Moreover, the analysis indicates that the presence of plasma in the proposed optical fiber could extend the possibilities for controlling the propagation property. The proposed structure presents itself as a promising route to advanced optical processing and opens new avenues in applied optics and photonics.

Optical-fiber interferometer for velocity measurements with picosecond resolution

International Nuclear Information System (INIS)

Weng Jidong; Tan Hua; Wang Xiang; Ma Yun; Hu Shaolou; Wang Xiaosong

2006-01-01

The conventional Doppler laser-interference velocimeters are made up of traditional optical elements such as lenses and mirrors and will generally restrict its applications in multipoint velocity measurements. By transfering the light from multimode optical fiber to single-mode optical fiber and using the currently available conventional telecommunications elements, the authors have constructed a velocimeter called all-fiber displacement interferometer system for any reflector. The unique interferometer system is only made up of fibers or fiber-coupled components. The viability of this technique is demonstrated by measuring the velocity of an interface moving at velocity of 2133 m/s with 50 ps time resolution. In addition, the concept of optical-fiber mode conversion would provide a way to develop various optical-fiber sensors

Scintillating optical fibers for fine-grained hodoscopes

International Nuclear Information System (INIS)

Borenstein, S.R.; Strand, R.C.

1981-01-01

Fast detectors with fine spatial resolution will be needed to exploit high event rates at ISABELLE. Scintillating optical fibers for fine grained hodoscopes have been developed by the authors. A commercial manufacturer of optical fibers has drawn and clad PVT scintillator. Detection efficiencies greater than 99% have been achieved for a 1 mm fiber with a PMT over lengths up to 60 cm. Small diameter PMT's and avalanche photodiodes have been tested with the fibers. Further improvements are sought for the fiber and for the APD's sensitivity and coupling efficiency with the fiber

Fluoride glass fiber optics

CERN Document Server

Aggarwal, Ishwar D

1991-01-01

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

Bridge SHM system based on fiber optical sensing technology

Science.gov (United States)

Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

2015-09-01

The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

SU-E-T-610: Phosphor-Based Fiber Optic Probes for Proton Beam Characterization

Energy Technology Data Exchange (ETDEWEB)

Darafsheh, A; Soldner, A; Liu, H; Kassaee, A; Zhu, T; Finlay, J [Univ Pennsylvania, Philadelphia, PA (United States)

2015-06-15

Purpose: To investigate feasibility of using fiber optics probes with rare-earth-based phosphor tips for proton beam radiation dosimetry. We designed and fabricated a fiber probe with submillimeter resolution (<0.5 mm3) based on TbF3 phosphors and evaluated its performance for measurement of proton beam including profiles and range. Methods: The fiber optic probe with TbF3 phosphor tip, embedded in tissue-mimicking phantoms was irradiated with double scattering proton beam with energy of 180 MeV. Luminescence spectroscopy was performed by a CCD-coupled spectrograph to analyze the emission spectra of the fiber tip. In order to measure the spatial beam profile and percentage depth dose, we used singular value decomposition method to spectrally separate the phosphors ionoluminescence signal from the background Cerenkov radiation signal. Results: The spectra of the TbF3 fiber probe showed characteristic ionoluminescence emission peaks at 489, 542, 586, and 620 nm. By using singular value decomposition we found the contribution of the ionoluminescence signal to measure the percentage depth dose in phantoms and compared that with measurements performed with ion chamber. We observed quenching effect at the spread out Bragg peak region, manifested as under-responding of the signal, due to the high LET of the beam. However, the beam profiles were not dramatically affected by the quenching effect. Conclusion: We have evaluated the performance of a fiber optic probe with submillimeter resolution for proton beam dosimetry. We demonstrated feasibility of spectral separation of the Cerenkov radiation from the collected signal. Such fiber probes can be used for measurements of proton beams profile and range. The experimental apparatus and spectroscopy method developed in this work provide a robust platform for characterization of proton-irradiated nanophosphor particles for ultralow fluence photodynamic therapy or molecular imaging applications.

Extended-length fiber optic carbon dioxide monitoring

Science.gov (United States)

Delgado-Alonso, Jesus; Lieberman, Robert A.

2013-05-01

This paper discusses the design and performance of fiber optic distributed intrinsic sensors for dissolved carbon dioxide, based on the use optical fibers fabricated so that their entire lengths are chemically sensitive. These fibers use a polymer-clad, silica-core structure where the cladding undergoes a large, reversible, change in optical absorbance in the presence of CO2. The local "cladding loss" induced by this change is thus a direct indication of the carbon dioxide concentration in any section of the fiber. To create these fibers, have developed a carbon dioxide-permeable polymer material that adheres well to glass, is physically robust, has a refractive index lower than fused silica, and acts as excellent hosts for a unique colorimetric indicator system that respond to CO2. We have used this proprietary material to produce carbon-dioxide sensitive fibers up to 50 meters long, using commercial optical fiber fabrication techniques. The sensors have shown a measurement range of dissolved CO2 of 0 to 1,450 mg/l (0 to 100% CO2 saturation), limit of detection of 0.3 mg/l and precision of 1.0 mg/l in the 0 to 50 mg/l dissolved CO2 range, when a 5 meter-long sensor fiber segment is used. Maximum fiber length, minimum detectable concentration, and spatial resolution can be adjusted by adjusting indicator concentration and fiber design.

A microbent fiber optic pH sensor

NARCIS (Netherlands)

Thomas Lee, S.; Aneeshkumar, B.N.; Radhakrishnan, P.; Vallabhan, C.P.G.; Nampoori, V.P.N.

2002-01-01

Optical fiber sensors developed for measuring pH values usually employ an unclad and unstrained section of the fiber. In this paper, we describe the design and fabrication of a microbent fiber optic sensor that can be used for pH sensing. In order to obtain the desired performance, a permanently

Fiber optic fluid detector

Science.gov (United States)

Angel, S. Michael

1989-01-01

Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

Bare Fiber Bragg Gratings embedded into concrete buffer Supercontainer concept for nuclear waste storage [ANIMMA--2015-IO-337

Energy Technology Data Exchange (ETDEWEB)

Kinet, Damien; Chah, Karima; Megret, Patrice; Caucheteur, Christophe [University of Mons, Boulevard Dolez 31, 7000 Mons (Belgium); Gusarov, Andrei [SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Faustov, Alexey [University of Mons, Boulevard Dolez 31, 7000 Mons (Belgium); SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Areias, Lou [Department Mechanics of Materials and Constructions - MeMC, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels (Belgium); EIG EURIDICE - European Underground Research Infrastructure for Disposal of nuclear waste In Clay Environment, Boeretang 200, 2400 Mol (Belgium)

2015-07-01

Nuclear power plants have been generating electricity for more than 50 years. In Belgium, 55% of the current energy supply comes from nuclear power. Providing for the safe storage of nuclear waste, including spent fuel (SF) and vitrified high level radioactive waste (HLW), remains an important challenge in the life cycle of nuclear fuel. In this context, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials (ONDRAF/NIRAS) is investigating a reference conceptual design called the Supercontainer (SC) for the packaging of SF and HLW. This conceptual design is based on a multiple-barrier system consisting of a hermetically-sealed carbon steel overpack and a surrounding highly-alkaline concrete buffer. The first one is developed to retain the radionuclides. The two main functions of the buffer are (a) to create a high pH environment around the carbon steel overpack in order to passivate the metal surface and so to slow down the corrosion propagation during the thermal phase and (b) to provide a radiological shielding during the construction and the handling of the Supercontainer. A recent test has been performed to investigate the feasibility to construct the SC. This test incorporated several kinds of sensors including Digital Image Correlation (DIC), Acoustic Emission (AE), corrosion sensing techniques and optical fibers with and without fiber Bragg gratings (FBGs). In particular, several single-mode optical fibers with 4 mm long FBGs with different Bragg wavelengths and distributed along the optical fibers were used. For casting and curing condition monitoring, a number of gratings were incorporated inside the concrete buffer during the first stage of construction. Then other sensors were embedded near a heat source installed in the second stage to simulate the effects of heat generated by radioactive waste. The FBGs were designed to measure both temperature and strain effects in the concrete. To discriminate between these effects special packaging

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

Directory of Open Access Journals (Sweden)

Xingjun Lv

2011-11-01

Full Text Available 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 is designed and conducted to obtain the strain coefficient of single mode fiber optics. Results have shown that there is a good linear relationship between Brillouin frequency and applied strain. Then, three kinds of novel fiber optical Brillouin corrosion expansion sensors with different fiber optic coil winding packaging schemes are designed. Sensors were embedded into concrete specimens to monitor expansion strain caused by steel rebar corrosion, and their performance was studied in a designed electrochemical corrosion acceleration experiment. Experimental results have shown that expansion strain along the fiber optic coil winding area can be detected and measured by the three kinds of sensors with different measurement range during development the corrosion. With the assumption of uniform corrosion, diameters of corrosion steel rebars were obtained using calculated average strains. A maximum expansion strain of 6,738 με was monitored. Furthermore, the uniform corrosion analysis model was established and the evaluation formula to evaluate mass loss rate of steel rebar under a given corrosion rust expansion rate was derived. The research has shown that three kinds of Brillouin sensors can be used to monitor the steel rebar corrosion expansion of reinforced concrete structures with good sensitivity, accuracy and monitoring range, and can be applied to monitor different levels of corrosion. By means of this kind of monitoring technique, quantitative corrosion expansion monitoring can be carried out, with the virtues of long durability, real-time monitoring and quasi-distribution monitoring.

Brillouin corrosion expansion sensors for steel reinforced concrete structures using a fiber optic coil winding method.

Science.gov (United States)

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

2011-01-01

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 is designed and conducted to obtain the strain coefficient of single mode fiber optics. Results have shown that there is a good linear relationship between Brillouin frequency and applied strain. Then, three kinds of novel fiber optical Brillouin corrosion expansion sensors with different fiber optic coil winding packaging schemes are designed. Sensors were embedded into concrete specimens to monitor expansion strain caused by steel rebar corrosion, and their performance was studied in a designed electrochemical corrosion acceleration experiment. Experimental results have shown that expansion strain along the fiber optic coil winding area can be detected and measured by the three kinds of sensors with different measurement range during development the corrosion. With the assumption of uniform corrosion, diameters of corrosion steel rebars were obtained using calculated average strains. A maximum expansion strain of 6,738 με was monitored. Furthermore, the uniform corrosion analysis model was established and the evaluation formula to evaluate mass loss rate of steel rebar under a given corrosion rust expansion rate was derived. The research has shown that three kinds of Brillouin sensors can be used to monitor the steel rebar corrosion expansion of reinforced concrete structures with good sensitivity, accuracy and monitoring range, and can be applied to monitor different levels of corrosion. By means of this kind of monitoring technique, quantitative corrosion expansion monitoring can be carried out, with the virtues of long durability, real-time monitoring and quasi-distribution monitoring.

46 CFR 111.60-6 - Fiber optic cable.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Fiber optic cable. 111.60-6 Section 111.60-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-6 Fiber optic cable. Each fiber optic cable must— (a) Be...

Modeling fiber Bragg grating device networks in photomechanical polymer optical fibers

Science.gov (United States)

Lanska, Joseph T.; Kuzyk, Mark G.; Sullivan, Dennis M.

2015-09-01

We report on the modeling of fiber Bragg grating (FBG) networks in poly(methyl methacrylate) (PMMA) polymer fibers doped with azo dyes. Our target is the development of Photomechanical Optical Devices (PODs), comprised of two FBGs in series, separated by a Fabry-Perot cavity of photomechanical material. PODs exhibit photomechanical multi-stability, with the capacity to access multiple length states for a fixed input intensity when a mechanical shock is applied. Using finite-difference time-domain (FDTD) numerical methods, we modeled the photomechanical response of both Fabry-Perot and Bragg-type PODs in a single polymer optical fiber. The polymer fiber was modeled as an instantaneous Kerr-type nonlinear χ(3) material. Our model correctly predicts the essential optical features of FBGs as well as the photomechanical multi-stability of nonlinear Fabry-Perot cavity-based PODs. Networks of PODs may provide a framework for smart shape-shifting materials and fast optical computation where the decision process is distributed over the entire network. In addition, a POD can act as memory, and its response can depend on input history. Our models inform and will accelerate targeted development of novel Bragg grating-based polymer fiber device networks for a variety of applications in optical computing and smart materials.

Radiation cured coatings for fiber optics

International Nuclear Information System (INIS)

Ketley, A.D.; Morgan, C.R.

1978-01-01

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 90 0 C and exposing the coated conductor to ultraviolet or high energy ionizing radiation to cure the coating

21 CFR 872.4620 - Fiber optic dental light.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fiber optic dental light. 872.4620 Section 872...) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4620 Fiber optic dental light. (a) Identification. A fiber optic dental light is a device that is a light, usually AC-powered, that consists of glass or...

Fabrication of Optical Fiber Devices

Science.gov (United States)

Andres, Miguel V.

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.

Fiber Optics: A New World of Possibilities in Light.

Science.gov (United States)

Hutchinson, John

1990-01-01

The background and history of light and fiber optics are discussed. Applications for light passed either directly or indirectly through optical fibers are described. Suggestions for science activities that use fiber optics are provided. (KR)

Rayleigh scattering in few-mode optical fibers.

Science.gov (United States)

Wang, Zhen; Wu, Hao; Hu, Xiaolong; Zhao, Ningbo; Mo, Qi; Li, Guifang

2016-10-24

The extremely low loss of silica fibers has enabled the telecommunication revolution, but single-mode fiber-optic communication systems have been driven to their capacity limits. As a means to overcome this capacity crunch, space-division multiplexing (SDM) using few-mode fibers (FMF) has been proposed and demonstrated. In single-mode optical fibers, Rayleigh scattering serves as the dominant mechanism for optical loss. However, to date, the role of Rayleigh scattering in FMFs remains elusive. Here we establish and experimentally validate a general model for Rayleigh scattering in FMFs. Rayleigh backscattering not only sets the intrinsic loss limit for FMFs but also provides the theoretical foundation for few-mode optical time-domain reflectometry, which can be used to probe perturbation-induced mode-coupling dynamics in FMFs. We also show that forward inter-modal Rayleigh scattering ultimately sets a fundamental limit on inter-modal-crosstalk for FMFs. Therefore, this work not only has implications specifically for SDM systems but also broadly for few-mode fiber optics and its applications in amplifiers, lasers, and sensors in which inter-modal crosstalk imposes a fundamental performance limitation.

Modeling illumination performance of plastic optical fiber passive daylighting system

Energy Technology Data Exchange (ETDEWEB)

Sulaiman, F; Ahmad, A [Universiti Teknologi MARA, Shah Alam (Malaysia). Faculty of Electrical Engineering; Ahmed, A Z [Universiti Teknologi MARA, Shah Alam (Malaysia). Bureau of Reseaarch and Consultancy

2006-12-15

of the most direct methods of utilizing solar energy for energy conservation is to bring natural light indoors to light up an area. This paper reports on the investigation of the feasibility to utilize large core optical fibers to convey and distribute solar light passively throughout residential or commercial structures. The focus of this study is on the mathematical modeling of the illumination performance and the light transmission efficiency of solid core end light fiber for optical day lighting systems. The Meatball simulations features the optical fiber transmittance for glass and plastic fibers, illumination performance over lengths of plastic end-lit fiber, spectral transmission, light intensity loss through the large diameter solid core optical fibers as well as the transmission efficiency of the optical fiber itself. It was found that plastic optical fiber has less transmission loss over the distance of the fiber run which clearly shows that the Plastic Optical Fiber should be optimized for emitting visible light. The findings from the analysis on the performance of large diameter optical fibers for day lighting systems seems feasible for energy efficient lighting system in commercial or residential buildings.

Modeling illumination performance of plastic optical fiber passive daylighting system

International Nuclear Information System (INIS)

Sulaiman, F.; Ahmad, A.; Ahmed, A.Z.

2006-01-01

One of the most direct methods of utilizing solar energy for energy conservation is to bring natural light indoors to light up an area. This paper reports on the investigation of the feasibility to utilize large core optical fibers to convey and distribute solar light passively throughout residential or commercial structures. The focus of this study is on the mathematical modeling of the illumination performance and the light transmission efficiency of solid core end light fiber for optical day lighting systems. The Meatball simulations features the optical fiber transmittance for glass and plastic fibers, illumination performance over lengths of plastic end-lit fiber, spectral transmission, light intensity loss through the large diameter solid core optical fibers as well as the transmission efficiency of the optical fiber itself. It was found that plastic optical fiber has less transmission loss over the distance of the fiber run which clearly shows that the Plastic Optical Fiber should be optimized for emitting visible light. The findings from the analysis on the performance of large diameter optical fibers for day lighting systems seems feasible for energy efficient lighting system in commercial or residential buildings

Radiation damage in optical fibers

International Nuclear Information System (INIS)

Lyons, P.B.; Looney, L.D.; Ogle, J.W.

1983-01-01

Optical fibers provide important advantages over coaxial cables for many data transmission applications. Some of these applications require that the fibers transmit data during a radiation pulse. Other applications utilize the fiber as a radiation-to-light transducer. In either case, radiation-induced luminescence and absorption must be understood. Most studies of radiation effects in fibers have emphasized time scales of interest in telecommunication systems, from the msec to hour range. Few studies have concentrated on response at times below 1 + s. At Los Alamos, both laboratory electron accelerators and nuclear tests have been used as radiation sources to probe this early time region. The use of a fiber (or any optical medium) as a Cerenkov radiation-to-light transducer is discussed. Since the radiation induces attenuation in the medium, the light output is not proportional to the radiation input. The nonlinearity introduced by this attenuation is calculated

Fiber-Optic Monitoring System of Particle Counters

Directory of Open Access Journals (Sweden)

A. A. Titov

2016-01-01

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

Optical Fiber Spectroscopy

Science.gov (United States)

Buoncristiani, A. M.

1999-01-01

This is the final report of work done on NASA Grant NAG-1-443. The work covers the period from July 1, 1992 to December 1, 1998. During this period several distinct but related research studies and work tasks were undertaken. These different subjects are enumerated below with a description of the work done on each of them. The focus of the research was the development of optical fibers for use as distributed temperature and stress sensors. The initial concept was to utilize the utilize the temperature and stress dependence of emission from rare earth and transition metal ions substitutionally doped into crystalline or glass fibers. During the course of investigating this it became clear that fiber Bragg gratings provided a alternative for making the desired measurements and there was a shift of research focus on to include the photo-refractive properties of germano-silicate glasses used for most gratings and to the possibility of developing fiber laser sources for an integrated optical sensor in the research effort. During the course of this work several students from Christopher Newport University and other universities participated in this effort. Their names are listed below. Their participation was an important part of their education.

Development of an optical fiber flow velocity sensor.

Science.gov (United States)

Harada, Toshio; Kamoto, Kenji; Abe, Kyutaro; Izumo, Masaki

2009-01-01

A new optical fiber flow velocity sensor was developed by using an optical fiber information network system in sewer drainage pipes. The optical fiber flow velocity sensor operates without electric power, and the signals from the sensor can be transmitted over a long distance through the telecommunication system in the optical fiber network. Field tests were conducted to check the performance of the sensor in conduits in the pumping station and sewage pond managed by the Tokyo Metropolitan Government. Test results confirmed that the velocity sensor can be used for more than six months without any trouble even in sewer drainage pipes.

Experimental refractive index determination of the optic fiber's core

International Nuclear Information System (INIS)

Oezelsoy, S.

2005-01-01

In this work, the Fresnel's fundamental Law was used to be able to obtain the refractive index of the fiber optic's core. The intensity of light reflected from the boundary between two mediums was measured by the optical powermeter (Melles Griot, Universal optical powermeter). In recent technology, the light that is illuminated from the light source can be transported to the boundary region and measured with minimum loss by using the optic fibers which make the measurement more sensitively. The liquid and the optic fiber's core whose refractive indices will be measured are the two mediums and the surface of the optic fiber's core is the boundary region. By dipping the fiber optic probe to the liquids, the reflected light intensities were measured with powermeter via Silicon Detector for single mode fiber and multimode fiber respectively to obtain the refractive index of the optic fiber's core. At this work, because of the using the diode laser with 661,4 nm (FWHM) and He-Ne laser with 632,8 nm (FWHM) the refractive indices were measured at this wavelengthes with the Refractometer (Abbe 60-70, Bellingham+Stanley). If the refractive indices of two mediums are equal, the light doesn't reflect from the boundary. The graphic is drawn depend upon the refractive index of the liquids versus the back reflected light energy and from the minimum point of the curve the effective refractive index of the fiber optic's core is calculated for 661,4 nm and 780 nm

Effects of accelerated artificial daylight aging on bending strength and bonding of glass fibers in fiber-embedded maxillofacial silicone prostheses.

Science.gov (United States)

Hatamleh, Muhanad M; Watts, David C

2010-07-01

The purpose of this study was to test the effect of different periods of accelerated artificial daylight aging on bond strength of glass fiber bundles embedded into maxillofacial silicone elastomer and on bending strength of the glass fiber bundles. Forty specimens were fabricated by embedding resin-impregnated fiber bundles (1.5-mm diameter, 20-mm long) into maxillofacial silicone elastomer. Specimens were randomly allocated into four groups, and each group was subjected to different periods of accelerated daylight aging as follows (in hours); 0, 200, 400, and 600. The aging cycle included continuous exposure to quartz-filtered visible daylight (irradiance 760 W/m(2)) under an alternating weathering cycle (wet for 18 minutes, dry for 102 minutes). Pull-out tests were performed to evaluate bond strength between fiber bundles and silicone using a universal testing machine at 1 mm/min crosshead speed. Also a three-point bending test was performed to evaluate bending strength of the fiber bundles. One-way ANOVA and Bonferroni post hoc tests were carried out to detect statistical significance (p aging only. After 200 hours of exposure to artificial daylight and moisture conditions, bond strength between glass fibers and heat-cured silicones is optimal, and the bending strength of the glass fiber bundles is enhanced.

Optical Fiber Sensors Based on Fiber Ring Laser Demodulation Technology.

Science.gov (United States)

Xie, Wen-Ge; Zhang, Ya-Nan; Wang, Peng-Zhao; Wang, Jian-Zhang

2018-02-08

A review for optical fiber sensors based on fiber ring laser (FRL) demodulation technology is presented. The review focuses on the principles, main structures, and the sensing performances of different kinds of optical fiber sensors based on FRLs. First of all, the theory background of the sensors has been discussed. Secondly, four different types of sensors are described and compared, which includes Mach-Zehnder interferometer (MZI) typed sensors, Fabry-Perot interferometer (FPI) typed sensors, Sagnac typed sensors, and fiber Bragg grating (FBG) typed sensors. Typical studies and main properties of each type of sensors are presented. Thirdly, a comparison of different types of sensors are made. Finally, the existing problems and future research directions are pointed out and analyzed.

Selection of fiber-optical components for temperature measurement for satellite applications

Science.gov (United States)

Putzer, P.; Kuhenuri Chami, N.; Koch, A. W.; Hurni, A.; Roner, M.; Obermaier, J.; Lemke, N. M. K.

2017-11-01

The Hybrid Sensor Bus (HSB) is a modular system for housekeeping measurements for space applications. The focus here is the fiber-optical module and the used fiber-Bragg gratings (FBGs) for temperature measurements at up to 100 measuring points. The fiber-optial module uses a tunable diode laser to scan through the wavelength spectrum and a passive optical network for reading back the reflections from the FBG sensors. The sensors are based on FBGs which show a temperature dependent shift in wavelength, allowing a high accuracy of measurement. The temperature at each sensor is derivated from the sensors Bragg wavelength shift by evaluating the measured spectrum with an FBG peak detection algorithm and by computing the corresponding temperature difference with regard to the calibration value. It is crucial to eliminate unwanted influence on the measurement accuracy through FBG wavelength shifts caused by other reasons than the temperature change. The paper presents gamma radiation test results up to 25 Mrad for standard UV-written FBGs in a bare fiber and in a mechanically housed version. This high total ionizing dose (TID) load comes from a possible location of the fiber outside the satellite's housing, like e.g. on the panels or directly embedded into the satellites structure. Due to the high shift in wavelength of the standard written gratings also the femto-second infrared (fs- IR) writing technique is investigated in more detail. Special focus is given to the deployed fibers for the external sensor network. These fibers have to be mechanically robust and the radiation induced attenuation must be low in order not to influence the system's performance. For this reason different fiber types have been considered and tested to high dose gamma radiation. Dedicated tests proved the absence of enhanced low dose rate sensitivity (ELDRS). Once the fiber has been finally selected, the fs-IR grating will be written to these fibers and the FBGs will be tested in order to

Supersymmetric Transformations in Optical Fibers

Science.gov (United States)

Macho, Andrés; Llorente, Roberto; García-Meca, Carlos

2018-01-01

Supersymmetry (SUSY) has recently emerged as a tool to design unique optical structures with degenerate spectra. Here, we study several fundamental aspects and variants of one-dimensional SUSY in axially symmetric optical media, including their basic spectral features and the conditions for degeneracy breaking. Surprisingly, we find that the SUSY degeneracy theorem is partially (totally) violated in optical systems connected by isospectral (broken) SUSY transformations due to a degradation of the paraxial approximation. In addition, we show that isospectral constructions provide a dimension-independent design control over the group delay in SUSY fibers. Moreover, we find that the studied unbroken and isospectral SUSY transformations allow us to generate refractive-index superpartners with an extremely large phase-matching bandwidth spanning the S +C +L optical bands. These singular features define a class of optical fibers with a number of potential applications. To illustrate this, we numerically demonstrate the possibility of building photonic lanterns supporting broadband heterogeneous supermodes with large effective area, a broadband all-fiber true-mode (de)multiplexer requiring no mode conversion, and different mode-filtering, mode-conversion, and pulse-shaping devices. Finally, we discuss the possibility of extrapolating our results to acoustics and quantum mechanics.

Fiber optic evanescent wave biosensor

Science.gov (United States)

Duveneck, Gert L.; Ehrat, Markus; Widmer, H. M.

1991-09-01

The role of modern analytical chemistry is not restricted to quality control and environmental surveillance, but has been extended to process control using on-line analytical techniques. Besides industrial applications, highly specific, ultra-sensitive biochemical analysis becomes increasingly important as a diagnostic tool, both in central clinical laboratories and in the doctor's office. Fiber optic sensor technology can fulfill many of the requirements for both types of applications. As an example, the experimental arrangement of a fiber optic sensor for biochemical affinity assays is presented. The evanescent electromagnetic field, associated with a light ray guided in an optical fiber, is used for the excitation of luminescence labels attached to the biomolecules in solution to be analyzed. Due to the small penetration depth of the evanescent field into the medium, the generation of luminescence is restricted to the close proximity of the fiber, where, e.g., the luminescent analyte molecules combine with their affinity partners, which are immobilized on the fiber. Both cw- and pulsed light excitation can be used in evanescent wave sensor technology, enabling the on-line observation of an affinity assay on a macroscopic time scale (seconds and minutes), as well as on a microscopic, molecular time scale (nanoseconds or microseconds).

Irradiation of fiber optics in the SSC tunnel

International Nuclear Information System (INIS)

Dickey, C.E.

1990-03-01

The salient question is not whether optical fiber will survive in the Super Conducting Supercollider (SSC) tunnel, but rather how long will it survive. Current estimates indicate that single mode fiber under ideal conditions will have an expected lifetime of at least 25 years. Future development of optical fiber will lead to longer service lifetimes and increased radiation hardness. But conservatively speaking, current production optical fibers can probably not be depended upon for more than 25 years of service even under ideal conditions

Radiative properties of optical board embedded with optical black holes

International Nuclear Information System (INIS)

Qiu, J.; Liu, L.H.; Hsu, P.-F.

2011-01-01

Unique radiative properties, such as wavelength-selective transmission or absorption, have been intensively studied. Historically, geometries for wavelength-selective of light absorption were developed based on metallic periodical structures, which were only applied in the case of TM wave incidence due to the excitation of surface plasmons. In this paper, we develop an alternative approach to selective wavelength of light absorption (both TE and TM waves), based on an optical board periodical embedded with optical black holes. Numerical work was carried out to study such structure's radiative properties within the wavelength range of 1-100 μm. The electromagnetic wave transmission through such a structure is predicted by solving Maxwell's equations using the finite-difference time-domain (FDTD) method. Spectral absorptance varies with the period of optical black holes. When the incidence wavelength is much larger than the inner core radius, most of the light energy will be transmitted through the inner core. Otherwise, the energy will be mainly absorbed. Numerical results of the radiative properties of the optical board with different incidence wavelengths are also obtained. The effect of the oblique incidence wave is investigated. This study helps us gain a better understanding of the radiative properties of an optical board embedded with optical black holes and develop an alternative approach to selective light absorption.

Improving fiber-optic laser beam delivery by incorporating GRADIUM optics

International Nuclear Information System (INIS)

Hunter, B.V.; Leong, K.H.

1997-01-01

The performance of a fiber-optic laser beam delivery system strongly depends on the fiber and the optics used to image the fiber face on the workpiece. We have compared off-the-shelf homogenous (BK7) and GRADIUM (axial-gradient) singlets to determine what improvement the GRADIUM offers in practice to the typical laser user. The realized benefit for this application, although significant, is much smaller than would be realized by a conventional imaging application. The figure of merit for laser-based materials processing is the 86% energy-enclosure radius, which is not directly supported by commerical ray-tracing software. Therefore empirical rules of thumb are presented to understand when GRADIUM (or any other well-corrected optics) will yield meaningful improvement to the beam delivery system. copyright 1997 Optical Society of America

Optical fiber head for providing lateral viewing

Science.gov (United States)

Everett, Matthew J.; Colston, Billy W.; James, Dale L.; Brown, Steve; Da Silva, Luiz

2002-01-01

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.

Characterization of Fiber Optic CMM Probe System

Energy Technology Data Exchange (ETDEWEB)

K.W.Swallow

2007-05-15

This report documents a study completed on the fiber optic probe system that is a part of the Werth optical CMM. This study was necessary due to a lack of documentation from the vendor for the proper use and calibration of the fiber probe, and was performed in support of the Lithographie Galvanoformung Abformung (LIGA) development program at the FM&T. As a result of this study, a better understanding of the fiber optic probe has been developed, including guidelines for its proper use and calibration.

Crystal-free Formation of Non-Oxide Optical Fiber

Science.gov (United States)

Nabors, Sammy A.

2015-01-01

Researchers at NASA Marshall Space Flight Center have devised a method for the creation of crystal-free nonoxide optical fiber preforms. Non-oxide fiber optics are extensively used in infrared transmitting applications such as communication systems, chemical sensors, and laser fiber guides for cutting, welding and medical surgery. However, some of these glasses are very susceptible to crystallization. Even small crystals can lead to light scatter and a high attenuation coefficient, limiting their usefulness. NASA has developed a new method of non-oxide fiber formation that uses axial magnetic fields to suppress crystallization. The resulting non-oxide fibers are crystal free and have lower signal attenuation rates than silica based optical fibers.

Fiber optic sensing for telecommunication satellites

Science.gov (United States)

Reutlinger, Arnd; Glier, Markus; Zuknik, Karl-Heinz; Hoffmann, Lars; Müller, Mathias; Rapp, Stephan; Kurvin, Charles; Ernst, Thomas; McKenzie, Iain; Karafolas, Nikos

2017-11-01

Modern telecommunication satellites can benefit from the features of fiber optic sensing wrt to mass savings, improved performance and lower costs. Within the course of a technology study, launched by the European Space Agency, a fiber optic sensing system has been designed and is to be tested on representative mockups of satellite sectors and environment.

Femtosecond Laser Structuring in Optical Fiber and Transparent Films

Directory of Open Access Journals (Sweden)

Herman Peter R.

2013-11-01

Full Text Available Femtosecond laser processing is optimized for writing optical circuits, optical resonators, and microfluidic devices inside the cladding of single-mode optical fiber that couple efficiently with the fiber core waveguide. The laser processes open new directions towards Labon-a-Fiber.

Neural networks within multi-core optic fibers.

Science.gov (United States)

Cohen, Eyal; Malka, Dror; Shemer, Amir; Shahmoon, Asaf; Zalevsky, Zeev; London, Michael

2016-07-07

Hardware implementation of artificial neural networks facilitates real-time parallel processing of massive data sets. Optical neural networks offer low-volume 3D connectivity together with large bandwidth and minimal heat production in contrast to electronic implementation. Here, we present a conceptual design for in-fiber optical neural networks. Neurons and synapses are realized as individual silica cores in a multi-core fiber. Optical signals are transferred transversely between cores by means of optical coupling. Pump driven amplification in erbium-doped cores mimics synaptic interactions. We simulated three-layered feed-forward neural networks and explored their capabilities. Simulations suggest that networks can differentiate between given inputs depending on specific configurations of amplification; this implies classification and learning capabilities. Finally, we tested experimentally our basic neuronal elements using fibers, couplers, and amplifiers, and demonstrated that this configuration implements a neuron-like function. Therefore, devices similar to our proposed multi-core fiber could potentially serve as building blocks for future large-scale small-volume optical artificial neural networks.

Direct Embedding of Fiber-Optical Load Sensors into Wind Turbine Blades

DEFF Research Database (Denmark)

Glavind, Lars; Buggy, Stephen; Olesen, Ib S.

Long Period Gratings were embedded into the adhesive utilized in the matrix of a wind turbine blade. The LPGs were subsequently subjected to temperature-testing in order to assess their performance, which illustrates good embedding capabilities....

Fiber Optic Sensors for Health Monitoring of Morphing Airframes. Part 2; Chemical Sensing Using Optical Fibers with Bragg Gratings

Science.gov (United States)

Wood, Karen; Brown, Timothy; Rogowski, Robert; Jensen, Brian

2000-01-01

Part 1 of this two part series described the fabrication and calibration of Bragg gratings written into a single mode optical fiber for use in strain and temperature monitoring. Part 2 of the series describes the use of identical fibers and additional multimode fibers, both with and without Bragg gratings, to perform near infrared spectroscopy. The demodulation system being developed at NASA Langley Research Center currently requires the use of a single mode optical fiber. Attempts to use this single mode fiber for spectroscopic analysis are problematic given its small core diameter, resulting in low signal intensity. Nonetheless, we have conducted a preliminary investigation using a single mode fiber in conjunction with an infrared spectrometer to obtain spectra of a high-performance epoxy resin system. Spectra were obtained using single mode fibers that contained Bragg gratings; however, the peaks of interest were barely discernible above the noise. The goal of this research is to provide a multipurpose sensor in a single optical fiber capable of measuring a variety of chemical and physical properties.

Effects of Temperature and X-rays on Plastic Scintillating Fiber and Infrared Optical Fiber.

Science.gov (United States)

Lee, Bongsoo; Shin, Sang Hun; Jang, Kyoung Won; Yoo, Wook Jae

2015-05-11

In this study, we have studied the effects of temperature and X-ray energy variations on the light output signals from two different fiber-optic sensors, a fiber-optic dosimeter (FOD) based on a BCF-12 as a plastic scintillating fiber (PSF) and a fiber-optic thermometer (FOT) using a silver halide optical fiber as an infrared optical fiber (IR fiber). During X-ray beam irradiation, the scintillating light and IR signals were measured simultaneously using a dosimeter probe of the FOD and a thermometer probe of the FOT. The probes were placed in a beaker with water on the center of a hotplate, under variation of the tube potential of a digital radiography system or the temperature of the water in the beaker. From the experimental results, in the case of the PSF, the scintillator light output at the given tube potential decreased as the temperature increased in the temperature range from 25 to 60 °C. We demonstrated that commonly used BCF-12 has a significant temperature dependence of -0.263 ± 0.028%/°C in the clinical temperature range. Next, in the case of the IR fiber, the intensity of the IR signal was almost uniform at each temperature regardless of the tube potential range from 50 to 150 kVp. Therefore, we also demonstrated that the X-ray beam with an energy range used in diagnostic radiology does not affect the IR signals transmitted via a silver halide optical fiber.

Hot Springs-Garrison Fiber Optic Project

International Nuclear Information System (INIS)

1994-10-01

Bonneville Power Administration (BPA) is proposing to upgrade its operational telecommunications system between the Hot Springs Substation and the Garrison Substation using a fiber optic system. The project would primarily involve installing 190 kilometers (120 miles) of fiber optic cable on existing transmission structures and installing new fiber optic equipment in BPA's substation yards and control houses. BPA prepared an environmental assessment (EA) evaluating the proposed action. This EA was published in October 1994. The EA identifies a number of minor impacts that might occur as a result of the proposed action, as well as some recommended mitigation measures. This Mitigation Action Plan (MAP) identifies specific measures to avoid, minimize, or compensate for impacts identified in the EA

Hot Springs-Garrison Fiber Optic Project

Energy Technology Data Exchange (ETDEWEB)

1994-10-01

Bonneville Power Administration (BPA) is proposing to upgrade its operational telecommunications system between the Hot Springs Substation and the Garrison Substation using a fiber optic system. The project would primarily involve installing 190 kilometers (120 miles) of fiber optic cable on existing transmission structures and installing new fiber optic equipment in BPA`s substation yards and control houses. BPA prepared an environmental assessment (EA) evaluating the proposed action. This EA was published in October 1994. The EA identifies a number of minor impacts that might occur as a result of the proposed action, as well as some recommended mitigation measures. This Mitigation Action Plan (MAP) identifies specific measures to avoid, minimize, or compensate for impacts identified in the EA.

Recent Development in Optical Fiber Biosensors

Directory of Open Access Journals (Sweden)

Catalina Bosch Ojeda

2007-06-01

Full Text Available Remarkable developments can be seen in the field of optical fibre biosensors in the last decade. More sensors for specific analytes have been reported, novel sensing chemistries or transduction principles have been introduced, and applications in various analytical fields have been realised. This review consists of papers mainly reported in the last decade and presents about applications of optical fiber biosensors. Discussions on the trends in optical fiber biosensor applications in real samples are enumerated.

Casing Pipe Damage Detection with Optical Fiber Sensors: A Case Study in Oil Well Constructions

Directory of Open Access Journals (Sweden)

Zhi Zhou

2010-01-01

Full Text Available Casing pipes in oil well constructions may suddenly buckle inward as their inside and outside hydrostatic pressure difference increases. For the safety of construction workers and the steady development of oil industries, it is critically important to measure the stress state of a casing pipe. This study develops a rugged, real-time monitoring, and warning system that combines the distributed Brillouin Scattering Time Domain Reflectometry (BOTDR and the discrete fiber Bragg grating (FBG measurement. The BOTDR optical fiber sensors were embedded with no optical fiber splice joints in a fiber-reinforced polymer (FRP rebar and the FBG sensors were wrapped in epoxy resins and glass clothes, both installed during the segmental construction of casing pipes. In situ tests indicate that the proposed sensing system and installation technique can survive the downhole driving process of casing pipes, withstand a harsh service environment, and remain intact with the casing pipes for compatible strain measurements. The relative error of the measured strains between the distributed and discrete sensors is less than 12%. The FBG sensors successfully measured the maximum horizontal principal stress with a relative error of 6.7% in comparison with a cross multipole array acoustic instrument.

Use of optical fibers in spectrophotometry

Science.gov (United States)

Ramsey, Lawrence W.

1988-01-01

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

Recent Developments in Fiber Optics Humidity Sensors.

Science.gov (United States)

Ascorbe, Joaquin; Corres, Jesus M; Arregui, Francisco J; Matias, Ignacio R

2017-04-19

A wide range of applications such as health, human comfort, agriculture, food processing and storage, and electronic manufacturing, among others, require fast and accurate measurement of humidity. Sensors based on optical fibers present several advantages over electronic sensors and great research efforts have been made in recent years in this field. The present paper reports the current trends of optical fiber humidity sensors. The evolution of optical structures developed towards humidity sensing, as well as the novel materials used for this purpose, will be analyzed. Well-known optical structures, such as long-period fiber gratings or fiber Bragg gratings, are still being studied towards an enhancement of their sensitivity. Sensors based on lossy mode resonances constitute a platform that combines high sensitivity with low complexity, both in terms of their fabrication process and the equipment required. Novel structures, such as resonators, are being studied in order to improve the resolution of humidity sensors. Moreover, recent research on polymer optical fibers suggests that the sensitivity of this kind of sensor has not yet reached its limit. Therefore, there is still room for improvement in terms of sensitivity and resolution.

Residual strain sensor using Al-packaged optical fiber and Brillouin optical correlation domain analysis.

Science.gov (United States)

Choi, Bo-Hun; Kwon, Il-Bum

2015-03-09

We propose a distributed residual strain sensor that uses an Al-packaged optical fiber for the first time. The residual strain which causes Brillouin frequency shifts in the optical fiber was measured using Brillouin optical correlation domain analysis with 2 cm spatial resolution. We quantified the Brillouin frequency shifts in the Al-packaged optical fiber by the tensile stress and compared them for a varying number of Al layers in the optical fiber. The Brillouin frequency shift of an optical fiber with one Al layer had a slope of 0.038 MHz/με with respect to tensile stress, which corresponds to 78% of that for an optical fiber without Al layers. After removal of the stress, 87% of the strain remained as residual strain. When different tensile stresses were randomly applied, the strain caused by the highest stress was the only one detected as residual strain. The residual strain was repeatedly measured for a time span of nine months for the purpose of reliability testing, and there was no change in the strain except for a 4% reduction, which is within the error tolerance of the experiment. A composite material plate equipped with our proposed Al-packaged optical fiber sensor was hammered for impact experiment and the residual strain in the plate was successfully detected. We suggest that the Al-packaged optical fiber can be adapted as a distributed strain sensor for smart structures, including aerospace structures.

Utilization of Infrared Fiber Optic in the Automotive Industry

Science.gov (United States)

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

2001-01-01

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

Radiation resistant characteristics of optical fibers

International Nuclear Information System (INIS)

Nakasuji, Masaaki; Tanaka, Gotaro; Watanabe, Minoru; Kyodo, Tomohisa; Mukunashi, Hiroaki

1983-01-01

It is required to develop the optical fibers with good radiation resistivity because the fibers cause the increase of transmission loss due to glass colouring when they are used under the presence of radiation such as γ-ray. Generally, it is known that SI (step index) fibers are more resistive to radiation than GI (graded index) fibers. However, since a wide band can not be obtained with SI fibers, the development of radiation resistive GI optical fibers is desirable. In this report, the production for trial of the GI fibers of fluorine-doped silica core, the examination of radiation effect on their optical transmission loss by exposing them to γ-ray, thermal and fast neutron beams and also of mechanical strength are described. The GI fibers of fluorine-doped silica core show better radiation resistivity than Ge-doped ones. The B- and F-doped GI fibers show small increase of loss due to γ-ray, but large increase of loss due to thermal neutron beam. This is supposed to be caused by the far greater neutron absorption cross-section of boron than that of other elements. Significant increase of loss was not recognized when 14 MeV fast neutrons (8.6 x 10 4 n/cm 2 .s) were applied by 1.8 x 10 9 n/cm 2 . It was found that ETFE-covered fiber cores generated fluorine-containing gas due to γ irradiation, and the strength was remarkably lowered, but the lowering of strength can be prevented by adding titanium-white to the covering material. (Wakatsuki, Y.)

Optical fibers and their instrumentation applications

International Nuclear Information System (INIS)

Boisde, Gilbert.

1982-09-01

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) [fr

Lab-on-fiber electrophoretic trace mixture separating and detecting an optofluidic device based on a microstructured optical fiber.

Science.gov (United States)

Yang, Xinghua; Guo, Xiaohui; Li, Song; Kong, Depeng; Liu, Zhihai; Yang, Jun; Yuan, Libo

2016-04-15

We report an in-fiber integrated electrophoretic trace mixture separating and detecting an optofluidic optical fiber sensor based on a specially designed optical fiber. In this design, rapid in situ separation and simultaneous detection of mixed analytes can be realized under electro-osmotic flow in the microstructured optical fiber. To visually display the in-fiber separating and detecting process, two common fluorescent indicators are adopted as the optofluidic analytes in the optical fiber. Results show that a trace amount of the mixture (0.15 μL) can be completely separated within 3.5 min under a high voltage of 5 kV. Simultaneously, the distributed information of the separated analytes in the optical fiber can be clearly obtained by scanning along the optical fiber using a 355 nm laser. The emission from the analytes can be efficiently coupled into the inner core and guides to the remote end of the optical fiber. In addition, the thin cladding around the inner core in the optical fiber can prevent the fluorescent cross talk between the analytes in this design. Compared to previous optical fiber optofluidic devices, this device first realizes simultaneously separating treatment and the detection of the mixed samples in an optical fiber. Significantly, such an in-fiber integrated separating and detecting optofluidic device can find wide applications in various analysis fields involves mixed samples, such as biology, chemistry, and environment.

Smart pillow for heart-rate monitoring using a fiber optic sensor

Science.gov (United States)

Chen, Zhihao; Teo, Ju Teng; Ng, Soon Huat; Yim, Huiqing

2011-03-01

In this paper, we propose and demonstrate a new method to monitor heart rate using fiber optic microbending based sensor for in-bed non-intrusive monitoring. The sensing system consists of transmitter, receiver, sensor mat, National Instrument (NI) data acquisition (DAQ) card and a computer for signal processing. The sensor mat is embedded inside a commercial pillow. The heart rate measurement system shows an accuracy of +/-2 beats, which has been successfully demonstrated in a field trial. The key technological advantage of our system is its ability to measure heart rate with no preparation and minimal compliance by the patient.

Feasibility of Ultra-Thin Fiber-Optic Dosimeters for Radiotherapy Dosimetry.

Science.gov (United States)

Lee, Bongsoo; Kwon, Guwon; Shin, Sang Hun; Kim, Jaeseok; Yoo, Wook Jae; Ji, Young Hoon; Jang, Kyoung Won

2015-11-17

In this study, prototype ultra-thin fiber-optic dosimeters were fabricated using organic scintillators, wavelength shifting fibers, and plastic optical fibers. The sensor probes of the ultra-thin fiber-optic dosimeters consisted of very thin organic scintillators with thicknesses of 100, 150 and 200 μm. These types of sensors cannot only be used to measure skin or surface doses but also provide depth dose measurements with high spatial resolution. With the ultra-thin fiber-optic dosimeters, surface doses for gamma rays generated from a Co-60 therapy machine were measured. Additionally, percentage depth doses in the build-up regions were obtained by using the ultra-thin fiber-optic dosimeters, and the results were compared with those of external beam therapy films and a conventional fiber-optic dosimeter.

Noninvasive blood pressure measurement scheme based on optical fiber sensor

Science.gov (United States)

Liu, Xianxuan; Yuan, Xueguang; Zhang, Yangan

2016-10-01

Optical fiber sensing has many advantages, such as volume small, light quality, low loss, strong in anti-jamming. Since the invention of the optical fiber sensing technology in 1977, optical fiber sensing technology has been applied in the military, national defense, aerospace, industrial, medical and other fields in recent years, and made a great contribution to parameter measurement in the environment under the limited condition .With the rapid development of computer, network system, the intelligent optical fiber sensing technology, the sensor technology, the combination of computer and communication technology , the detection, diagnosis and analysis can be automatically and efficiently completed. In this work, we proposed a noninvasive blood pressure detection and analysis scheme which uses optical fiber sensor. Optical fiber sensing system mainly includes the light source, optical fiber, optical detector, optical modulator, the signal processing module and so on. wavelength optical signals were led into the optical fiber sensor and the signals reflected by the human body surface were detected. By comparing actual testing data with the data got by traditional way to measure the blood pressure we can establish models for predicting the blood pressure and achieve noninvasive blood pressure measurement by using spectrum analysis technology. Blood pressure measurement method based on optical fiber sensing system is faster and more convenient than traditional way, and it can get accurate analysis results in a shorter period of time than before, so it can efficiently reduce the time cost and manpower cost.

Multiplexed FBG and etched fiber sensors for process and health monitoring of 2-&3-D RTM components

OpenAIRE

Keulen, Casey J.; Yıldız, Mehmet; Yildiz, Mehmet; Suleman, Afzal

2011-01-01

This paper presents research being conducted on the use of a combination of fiber optic sensors for process and health monitoring of resin transfer molded (RTM) composite structures. A laboratory scale RTM apparatus has been designed and built with the capability of visually monitoring the resin filling process and embedding fiber optic sensors into the composite. Fiber Bragg gratings (FBG) and etched fiber sensors (EFS) have been multiplexed and embedded in quasi-2-D panels and 3-D hollow se...

Demonstration of theoretical and experimental simulations in fiber optics course

Science.gov (United States)

Yao, Tianfu; Wang, Xiaolin; Shi, Jianhua; Lei, Bing; Liu, Wei; Wang, Wei; Hu, Haojun

2017-08-01

"Fiber optics" course plays a supporting effect in the curriculum frame of optics and photonics at both undergraduate and postgraduate levels. Moreover, the course can be treated as compulsory for students specialized in the fiber-related field, such as fiber communication, fiber sensing and fiber light source. The corresponding content in fiber optics requires the knowledge of geometrical and physical optics as background, including basic optical theory and fiber components in practice. Thus, to help the students comprehend the relatively abundant and complex content, it is necessary to investigate novel teaching method assistant the classic lectures. In this paper, we introduce the multidimensional pattern in fiber-optics teaching involving theoretical and laboratory simulations. First, the theoretical simulations is demonstrated based on the self-developed software named "FB tool" which can be installed in both smart phone with Android operating system and personal computer. FB tool covers the fundamental calculations relating to transverse modes, fiber lasers and nonlinearities and so on. By comparing the calculation results with other commercial software like COMSOL, SFTool shows high accuracy with high speed. Then the laboratory simulations are designed including fiber coupling, Erbium doped fiber amplifiers, fiber components and so on. The simulations not only supports students understand basic knowledge in the course, but also provides opportunities to develop creative projects in fiber optics.

Miniature fiber-optic multiphoton microscopy system using frequency-doubled femtosecond Er-doped fiber laser.

Science.gov (United States)

Huang, Lin; Mills, Arthur K; Zhao, Yuan; Jones, David J; Tang, Shuo

2016-05-01

We report on a miniature fiber-optic multiphoton microscopy (MPM) system based on a frequency-doubled femtosecond Er-doped fiber laser. The femtosecond pulses from the laser source are delivered to the miniature fiber-optic probe at 1.58 µm wavelength, where a standard single mode fiber is used for delivery without the need of free-space dispersion compensation components. The beam is frequency-doubled inside the probe by a periodically poled MgO:LiNbO3 crystal. Frequency-doubled pulses at 786 nm with a maximum power of 80 mW and a pulsewidth of 150 fs are obtained and applied to excite intrinsic signals from tissues. A MEMS scanner, a miniature objective, and a multimode collection fiber are further used to make the probe compact. The miniature fiber-optic MPM system is highly portable and robust. Ex vivo multiphoton imaging of mammalian skins demonstrates the capability of the system in imaging biological tissues. The results show that the miniature fiber-optic MPM system using frequency-doubled femtosecond fiber laser can potentially bring the MPM imaging for clinical applications.

Optical bistability of optical fiber ring doped by Erbium and quantum dots

International Nuclear Information System (INIS)

Safari, S.; Tofighi, S.; Bahrampour, A.; Sajad, B.; Shahshahani, F.

2012-01-01

In this paper, theoretical analysis of the steady state behavior of the optical bistability in an optical fiber ring doped by Erbium and quantum dots is presented. The up and down switching power is calculated and the dependence of the switching power on different fiber ring parameters is investigated. The switching power for this type of optical bistability device is obtained much lower than the fiber ring which its half length is doped by Erbium ion.

Optical Fiber Grating Hydrogen Sensors: A Review.

Science.gov (United States)

Dai, Jixiang; Zhu, Li; Wang, Gaopeng; Xiang, Feng; Qin, Yuhuan; Wang, Min; Yang, Minghong

2017-03-12

In terms of hydrogen sensing and detection, optical fiber hydrogen sensors have been a research issue due to their intrinsic safety and good anti-electromagnetic interference. Among these sensors, hydrogen sensors consisting of fiber grating coated with sensitive materials have attracted intensive research interests due to their good reliability and distributed measurements. This review paper mainly focuses on optical fiber hydrogen sensors associated with fiber gratings and various materials. Their configurations and sensing performances proposed by different groups worldwide are reviewed, compared and discussed in this paper. Meanwhile, the challenges for fiber grating hydrogen sensors are also addressed.

Strain Measurement Using Embedded Fiber Bragg Grating Sensors Inside an Anchored Carbon Fiber Polymer Reinforcement Prestressing Rod for Structural Monitoring

DEFF Research Database (Denmark)

Kerrouche, Abdelfateh; Boyle, William J.O.; Sun, Tong

2009-01-01

Results are reported from a study carried out using a series of Bragg grating based optical fiber sensors written into a very short length (60mm) optical fiber net work and integrated into carbon fiber polymer reinforcement (CFPR) rod. Such rods are used as reinforcements in concrete structures...

US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 2: Fiber optic technology and long distance networks

Science.gov (United States)

1986-10-01

The study projects until 2000 the evolution of long distance fiber optic networks in the U.S. Volume 1 is the Executive Summary. Volume 2 focuses on fiber optic components and systems that are directly related to the operation of long-haul networks. Optimistic, pessimistic and most likely scenarios of technology development are presented. The activities of national and regional companies implementing fiber long haul networks are also highlighted, along with an analysis of the market and regulatory forces affecting network evolution. Volume 3 presents advanced fiber optic network concept definitions. Inter-LATA traffic is quantified and forms the basis for the construction of 11-, 15-, 17-, and 23-node networks. Using the technology projections from Volume 2, a financial model identifies cost drivers and determines circuit mile costs between any two LATAs. A comparison of fiber optics with alternative transmission concludes the report.

A microstructured Polymer Optical Fiber Biosensor

DEFF Research Database (Denmark)

Emiliyanov, Grigoriy Andreev; Jensen, Jesper Bo; Hoiby, Poul E.

2006-01-01

We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of the complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fibers.......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....

Design of a multimodal fibers optic system for small animal optical imaging.

Science.gov (United States)

Spinelli, Antonello E; Pagliazzi, Marco; Boschi, Federico

2015-02-01

Small animals optical imaging systems are widely used in pre-clinical research to image in vivo the bio-distribution of light emitting probes using fluorescence or bioluminescence modalities. In this work we presented a set of simulated results of a novel small animal optical imaging module based on a fibers optics matrix, coupled with a position sensitive detector, devoted to acquire bioluminescence and Cerenkov images. Simulations were performed using GEANT 4 code with the GAMOS architecture using the tissue optics plugin. Results showed that it is possible to image a 30 × 30 mm region of interest using a fiber optics array containing 100 optical fibers without compromising the quality of the reconstruction. The number of fibers necessary to cover an adequate portion of a small animal is thus quite modest. This design allows integrating the module with magnetic resonance (MR) in order to acquire optical and MR images at the same time. A detailed model of the mouse anatomy, obtained by segmentation of 3D MRI images, will improve the quality of optical 3D reconstruction. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

A new fiber optic sensor for inner surface roughness measurement

Science.gov (United States)

Xu, Xiaomei; Liu, Shoubin; Hu, Hong

2009-11-01

In order to measure inner surface roughness of small holes nondestructively, a new fiber optic sensor is researched and developed. Firstly, a new model for surface roughness measurement is proposed, which is based on intensity-modulated fiber optic sensors and scattering modeling of rough surfaces. Secondly, a fiber optical measurement system is designed and set up. Under the help of new techniques, the fiber optic sensor can be miniaturized. Furthermore, the use of micro prism makes the light turn 90 degree, so the inner side surface roughness of small holes can be measured. Thirdly, the fiber optic sensor is gauged by standard surface roughness specimens, and a series of measurement experiments have been done. The measurement results are compared with those obtained by TR220 Surface Roughness Instrument and Form Talysurf Laser 635, and validity of the developed fiber optic sensor is verified. Finally, precision and influence factors of the fiber optic sensor are analyzed.

Radiation hardening of optical fibers and fiber sensors for space applications: recent advances

Science.gov (United States)

Girard, S.; Ouerdane, Y.; Pinsard, E.; Laurent, A.; Ladaci, A.; Robin, T.; Cadier, B.; Mescia, L.; Boukenter, A.

2017-11-01

In these ICSO proceedings, we review recent advances from our group concerning the radiation hardening of optical fiber and fiber-based sensors for space applications and compare their benefits to state-of-the-art results. We focus on the various approaches we developed to enhance the radiation tolerance of two classes of optical fibers doped with rare-earths: the erbium (Er)-doped ones and the ytterbium/erbium (Er/Yb)-doped ones. As a first approach, we work at the component level, optimizing the fiber structure and composition to reduce their intrinsically high radiation sensitivities. For the Erbium-doped fibers, this has been achieved using a new structure for the fiber that is called Hole-Assisted Carbon Coated (HACC) optical fibers whereas for the Er/Ybdoped optical fibers, their hardening was successfully achieved adding to the fiber, the Cerium element, that prevents the formation of the radiation-induced point defects responsible for the radiation induced attenuation in the infrared part of the spectrum. These fibers are used as part of more complex systems like amplifiers (Erbium-doped Fiber Amplifier, EDFA or Yb-EDFA) or source (Erbium-doped Fiber Source, EDFS or Yb- EDFS), we discuss the impact of using radiation-hardened fibers on the system radiation vulnerability and demonstrate the resistance of these systems to radiation constraints associated with today and future space missions. Finally, we will discuss another radiation hardening approach build in our group and based on a hardening-by-system strategy in which the amplifier is optimized during its elaboration for its future mission considering the radiation effects and not in-lab.

Optical fiber designs for beam shaping

Science.gov (United States)

Farley, Kevin; Conroy, Michael; Wang, Chih-Hao; Abramczyk, Jaroslaw; Campbell, Stuart; Oulundsen, George; Tankala, Kanishka

2014-03-01

A large number of power delivery applications for optical fibers require beams with very specific output intensity profiles; in particular applications that require a focused high intensity beam typically image the near field (NF) intensity distribution at the exit surface of an optical fiber. In this work we discuss optical fiber designs that shape the output beam profile to more closely correspond to what is required in many real world industrial applications. Specifically we present results demonstrating the ability to transform Gaussian beams to shapes required for industrial applications and how that relates to system parameters such as beam product parameter (BPP) values. We report on the how different waveguide structures perform in the NF and show results on how to achieve flat-top with circular outputs.

Fiber break location technique utilizing stimulated Brillouin scattering effects in optical fiber

International Nuclear Information System (INIS)

Bakar, A A A; Al-Mansoori, M H; Mahdi, M A; Mohd Azau, M A; Zainal Abidin, M S

2009-01-01

A new technique of fiber break detection system in optical communication networks is proposed and experimentally demonstrated in this paper. This technique is based-on continuous wave light source rather than pulsed source that is commonly deployed in existing techniques. The nonlinear effect of stimulated Brillouin scattering is manipulated to locate the fiber-break position in optical communication networks. This technique enables the utilization of a less-sensitive photodetector to detect the Brillouin Stokes line since its intensity increases with the fiber length in the detectable region. The fiber break location can be determined with accuracy of more than 98% for fiber length less than 50 km using this technique

Optical frequency upconversion technique for transmission of wireless MIMO-type signals over optical fiber.

Science.gov (United States)

Shaddad, R Q; Mohammad, A B; Al-Gailani, S A; Al-Hetar, A M

2014-01-01

The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF) technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO) signals feeding multiple antennas in the fiber wireless (FiWi) system. A novel optical frequency upconversion (OFU) technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF). The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C) modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM). The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength.

Brillouin lasing in single-mode tapered optical fiber with inscribed fiber Bragg grating array

Directory of Open Access Journals (Sweden)

S.M. Popov

2018-06-01

Full Text Available A tapered optical fiber has been manufactured with an array of fiber Bragg gratings (FBG inscribed during the drawing process. The total fiber peak reflectivity is 5% and the reflection bandwidth is ∼3.5 nm. A coherent frequency domain reflectometry has been applied for precise profiling of the fiber core diameter and grating reflectivity both distributed along the whole fiber length. These measurements are in a good agreement with the specific features of Brillouin lasing achieved in the semi-open fiber cavity configuration. Keywords: Tapered optical fibers, Fiber Bragg gratings, Random lasers

All-optical fiber anemometer based on laser heated fiber Bragg gratings.

Science.gov (United States)

Gao, Shaorui; Zhang, A Ping; Tam, Hwa-Yaw; Cho, L H; Lu, Chao

2011-05-23

A fiber-optic anemometer based on fiber Bragg gratings (FBGs) is presented. A short section of cobalt-doped fiber was utilized to make a fiber-based "hot wire" for wind speed measurement. Fiber Bragg gratings (FBGs) were fabricated in the cobalt-doped fiber using 193 nm laser pulses to serve as localized temperature sensors. A miniature all-optical fiber anemometer is constructed by using two FBGs to determine the dynamic thermal equilibrium between the laser heating and air flow cooling through monitoring the FBGs' central wavelengths. It was demonstrated that the sensitivity of the sensor can be adjusted through the power of pump laser or the coating on the FBG. Experimental results reveal that the proposed FBG-based anemometer exhibits very good performance for wind speed measurement. The resolution of the FBG-based anemometer is about 0.012 m/s for wind speed range between 2.0 m/s and 8.0 m/s.

Temperature measurement distributed on a building by fiber optic BOTDA sensor

International Nuclear Information System (INIS)

Kwon, Il Bum; Kim, Chi Yeop; Choi, Man Yong; Lee, Seung Seok

2002-01-01

We have focused on the development of a fiber optic BOTDA (Brillouin Optical Time Domain Analysis) sensor system in order to measure temperature distributed on large structures. Also, we present a feasibility study of the fiber optic sensor to monitor the distributed temperature on a building construction. A fiber optic BOTDA sensor system, which has a capability of measuring the temperature distribution, attempted over several kilometers of long fiber paths. This simple fiber optic sensor system employs a laser diode and two electro-optic modulators. The optical fiber of the length of 1400 m was installed on the surfaces of the building. The change of the distributed temperature on the building construction was well measured by this fiber optic sensor. The temperature changed normally up to 4 degrees C through one day.

Electro-optical behaviour of silica optical fibers under transient ionizing irradiation

International Nuclear Information System (INIS)

Johan, A.; Charre, P.

1989-01-01

Centre d'Etudes de GRAMAT has perfected an experimental method on behaviour study for optical fiber under X-ray transient irradiation. This method allows recording of working light intensity in the fiber core or induced light (luminescence) during and after irradiation. The measured phenomena are the luminescence photon production and working light absorption. Monomode and multimode fiber behaviours have been studied and compared versus dose irradiation, light wavelength and injected optical power [fr

Dynamic Characterization of Polymer Optical Fibers

DEFF Research Database (Denmark)

Stefani, Alessio; Andresen, Søren; Yuan, Wu

2012-01-01

With the increasing interest in fiber sensors based on polymer optical fibers, it becomes fundamental to determine the real applicability and reliability of this type of sensor. The viscoelastic nature of polymers gives rise to questions about the mechanical behavior of the fibers. In particular...

Side-emitting fiber optic position sensor

Science.gov (United States)

Weiss, Jonathan D [Albuquerque, NM

2008-02-12

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

Damage and failure detection of composites using optical fiber vibration sensor

International Nuclear Information System (INIS)

Yang, Y. C.; Han, K. S.

2001-01-01

An intensity-based optical fiber vibration sensor is applied to detect and evaluate damages and fiber failure of composites. The optical fiber vibration sensor is constructed by placing two cleaved fiber end, one of which is cantilevered in a hollow glass tube. The movement of the cantilevered section lags behind the rest of the sensor in response to an applied vibration and the amount of light coupled between the two fibers is thereby modulated. Vibration characteristics of the optical fiber vibration sensor are investigated. Surface mounted optical fiber vibration sensor is used in tensile and indentation test. Experimental results show that the optical fiber sensor can detect damages and fiber failure of composites correctly

Study of light transmission through optical fiber-to-fiber connector assemblies

International Nuclear Information System (INIS)

Chung, M.; Gutowski, M.; Adams, M.; Solomon, J.

1998-01-01

Optical fiber-to-fiber connectors are now being used widely in particle tracking detectors. We describe the properties of the connectors, their production, and measurements of the light transmission through the gap of the connector assembly. We studied light transmission for various types of connectors illuminated by several different light sources. The light transmission was found to be dependent on the angular distribution of the light rays passing through a connector assembly. Two arrangements were studied, a point source and a diffuse source. A green LED with a diffuser is believed to best reproduce the angular distributions of light in the real detector applications. We also studied the transmission as a function of the index of refraction of the optical couplants. The light transmission depends on the index of refraction of an optical couplant placed in the gap, and improves as it approaches the index of refraction of the fiber core. Light transmissions of 80%∼88% were obtained without any optical couplant in the connector gap and transmissions of 89%∼99% with various optical couplants. A Monte Carlo study using measured light distributions from a fiber end produced a reasonable agreement with the transmission measurements made on a connector assembly

Study of light transmission through optical fiber-to-fiber connector assemblies

International Nuclear Information System (INIS)

Chung, M.; Gutowski, M.; Adams, M.; Solomon, J.

1998-01-01

Optical fiber-to-fiber connectors are now being used widely in particle tracking detectors. We describe the properties of the connectors, their production, and measurements of the light transmission through the gap of the connector assembly. We studied light transmission for various types of connectors illuminated by several different light sources. The light transmission was found to be dependent on the angular distribution of the light rays passing through a connector assembly. Two arrangements were studied, a point source and a diffuse source. A green LED with a diffuser is believed to best reproduce the angular distributions of light in the real detector applications. We also studied the transmission as a function of the index of refraction of the optical couplants. The light transmission depends on the index of refraction of an optical couplant placed in the gap, and improves as it approaches the index of refraction of the fiber core. Light transmissions of 80%∼88% were obtained without any optical couplant in the connector gap and transmissions of 89%∼99% with various optical couplants. A Monte Carlo study using measured light distributions from a fiber end produced a reasonable agreement with the transmission measurements made on a connector assembly. copyright 1998 American Institute of Physics

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

Directory of Open Access Journals (Sweden)

Fei Ye

2014-06-01

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

An in-fiber integrated optofluidic device based on an optical fiber with an inner core.

Science.gov (United States)

Yang, Xinghua; Yuan, Tingting; Teng, Pingping; Kong, Depeng; Liu, Chunlan; Li, Entao; Zhao, Enming; Tong, Chengguo; Yuan, Libo

2014-06-21

A new kind of optofluidic in-fiber integrated device based on a specially designed hollow optical fiber with an inner core is designed. The inlets and outlets are built by etching the surface of the optical fiber without damaging the inner core. A reaction region between the end of the fiber and a solid point obtained after melting is constructed. By injecting samples into the fiber, the liquids can form steady microflows and react in the region. Simultaneously, the emission from the chemiluminescence reaction can be detected from the remote end of the optical fiber through evanescent field coupling. The concentration of ascorbic acid (AA or vitamin C, Vc) is determined by the emission intensity of the reaction of Vc, H2O2, luminol, and K3Fe(CN)6 in the optical fiber. A linear sensing range of 0.1-3.0 mmol L(-1) for Vc is obtained. The emission intensity can be determined within 2 s at a total flow rate of 150 μL min(-1). Significantly, this work presents information for the in-fiber integrated optofluidic devices without spatial optical coupling.

Multi-Purpose Anthropomorphic Robotic Hand Design for Extra-Vehicular Activity Manipulation Tasks using Embedded Fiber Optic Sensors, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — IFOS proposes to design and build fiber-optically sensorized robotic fingers that can sense force and, objects using only tactile feedback, similar to the skin on a...

Switch configuration for migration to optical fiber network

Science.gov (United States)

Zobrist, George W.

1993-01-01

The purpose is to investigate the migration of an Ethernet LAN segment to fiber optics. At the present time it is proposed to support a Fiber Distributed Data Interface (FDDI) backbone and to upgrade the VAX cluster to fiber optic interface. Possibly some workstations will have an FDDI interface. The remaining stations on the Ethernet LAN will be segmented. The rationale for migrating from the present Ethernet configuration to a fiber optic backbone is due to the increase in the number of workstations and the movement of applications to a windowing environment, extensive document transfers, and compute intensive applications.

Raman Probe Based on Optically-Poled Double-Core Fiber

DEFF Research Database (Denmark)

Brunetti, Anna Chiara; Margulis, Walter; Rottwitt, Karsten

2012-01-01

A Raman probe based on an optically-poled double-core fiber. In-fiber SHG allows for Raman spectroscopy of DMSO at 532nm when illuminating the fiber with 1064nm light. The fiber structure provides independent excitation and collection paths.......A Raman probe based on an optically-poled double-core fiber. In-fiber SHG allows for Raman spectroscopy of DMSO at 532nm when illuminating the fiber with 1064nm light. The fiber structure provides independent excitation and collection paths....

7 CFR 1755.404 - Fiber optic cable telecommunications plant measurements.

Science.gov (United States)

2010-01-01

... performed on each optical fiber within the cable. (2) Method of measurement. For single mode fibers, the end-to-end attenuation measurements of each optical fiber at 1310 and/or 1550 nanometers in each...-end attenuation of each single mode optical fiber at 1310 and/or 1550 nanometers shall not exceed the...

Miniaturized Optical Tweezers Through Fiber-End Microfabrication

KAUST Repository

Liberale, Carlo; Cojoc, Gheorghe; Rajamanickam, Vijayakumar; Ferrara, Lorenzo; Bragheri, Francesca; Minzioni, Paolo; Perozziello, Gerardo; Candeloro, Patrizio; Cristiani, Ilaria; Di Fabrizio, Enzo M.

2014-01-01

Optical tweezers represent a powerful tool for a variety of applications both in biology and in physics, and their miniaturization and full integration is of great interest so as to reduce size (towards portable systems), and to minimize the required intervention from the operator. Optical fibers represent a natural solution to achieve this goal, and here we review the realization of single-fiber optical tweezers able to create a purely optical three-dimensional trap. © Springer International Publishing Switzerland 2015.

Miniaturized Optical Tweezers Through Fiber-End Microfabrication

KAUST Repository

Liberale, Carlo

2014-07-30

Optical tweezers represent a powerful tool for a variety of applications both in biology and in physics, and their miniaturization and full integration is of great interest so as to reduce size (towards portable systems), and to minimize the required intervention from the operator. Optical fibers represent a natural solution to achieve this goal, and here we review the realization of single-fiber optical tweezers able to create a purely optical three-dimensional trap. © Springer International Publishing Switzerland 2015.

Moiré phase-shifted fiber Bragg gratings in polymer optical fibers

DEFF Research Database (Denmark)

Min, Rui; Marques, Carlos; Bang, Ole

2018-01-01

We demonstrate a simple way to fabricate phase-shifted fiber Bragg grating in polymer optical fibers as a narrowband transmission filter for a variety of applications at telecom wavelengths. The filters have been fabricated by overlapping two uniform fiber Bragg gratings with slightly different...

New development in optical fibers for data center applications

Science.gov (United States)

Sun, Yi; Shubochkin, Roman; Zhu, Benyuan

2015-01-01

VCSEL-multimode optical fiber based links is the most successful optical technology in Data Centers. Laser-optimized multimode optical fibers, OM3 and OM4, have been the primary choice of physical media for 10 G serial, 4 x 10 G parallel, 10 x 10 G parallel, and 4 x 25 G parallel optical solutions in IEEE 802.3 standards. As the transition of high-end servers from 10 Gb/s to 40 Gb/s is driving the aggregation of speeds to 40 Gb/s now, and to 100 Gb/s and 400 Gb/s in near future, industry experts are coming together in IEEE 802.3bs 400 Gb/s study group and preliminary discussion of Terabit transmission for datacom applications has also been commenced. To meet the requirement of speed, capacity, density, power consumption and cost for next generation datacom applications, optical fiber design concepts beyond the standard OM3 and OM4 MMFs have a revived research and developmental interest, for example, wide band multimode optical fiber using multiple dopants for coarse wavelength division multiplexing; multicore multimode optical fiber using plural multimode cores in a single fiber strand to improve spatial density; and perhaps 50 Gb/s per lane and few mode fiber in spatial division multiplexing for ultimate capacity increase in far future. This talk reviews the multitude of fiber optic media being developed in the industry to address the upcoming challenges of datacom growth. We conclude that multimode transmission using low cost VCSEL technology will continue to be a viable solution for datacom applications.

Tunable light source for fiber optic lighting applications

Science.gov (United States)

Narendran, Nadarajah; Bierman, Andrew; Finney, Mark J.; Edwards, Ian K.

1997-09-01

This paper examines the possibility of tuning the lamp spectrum to compensate for color distortions in fiber optic lighting systems. Because most optical fibers have strong absorption in the blue and red wavelength regions, white light entering and propagating down an optical fiber suffers varied amounts of attenuation as a function of wavelength. As a result, the light exiting the optical fiber has a greenish tint that the lighting design community considers undesirable in interior lighting applications. HID lamps are commonly used for the light source in this industry. Certain classes of HID lamps tend to shift in color when their operating position or the input voltage to the lamp is changed. An experimental study is being conducted to characterize the color shift properties of a small HID lamp as a function of tilt and input voltage. The study also examines the possibility of exploiting this color shift to compensate for the color distortions caused by optical fibers. The details of the experiment and the results are presented in this manuscript.

Mach-Zehnder atom interferometer inside an optical fiber

Science.gov (United States)

Xin, Mingjie; Leong, Wuiseng; Chen, Zilong; Lan, Shau-Yu

2017-04-01

Precision measurement with light-pulse grating atom interferometry in free space have been used in the study of fundamental physics and applications in inertial sensing. Recent development of photonic band-gap fibers allows light for traveling in hollow region while preserving its fundamental Gaussian mode. The fibers could provide a very promising platform to transfer cold atoms. Optically guided matter waves inside a hollow-core photonic band-gap fiber can mitigate diffraction limit problem and has the potential to bring research in the field of atomic sensing and precision measurement to the next level of compactness and accuracy. Here, we will show our experimental progress towards an atom interferometer in optical fibers. We designed an atom trapping scheme inside a hollow-core photonic band-gap fiber to create an optical guided matter waves system, and studied the coherence properties of Rubidium atoms in this optical guided system. We also demonstrate a Mach-Zehnder atom interferometer in the optical waveguide. This interferometer is promising for precision measurements and designs of mobile atomic sensors.

Flexible optical fiber sensor based on polyurethane

DEFF Research Database (Denmark)

Kaysir, Md Rejvi; Stefani, Alessio; Lwin, Richard

Polyurethane (PU) based hollow core fibers are investigated as optical sensors. The flexibility of PU fibers makes it suitable for sensing mechanical perturbations. We fabricated a PU fiber using the fiber drawing method, characterized the fiber and experimentally demonstrated a simple way...... to measure deformation, in the form of applied pressure....

Mechanical and Vibration Testing of Carbon Fiber Composite Material with Embedded Piezoelectric Sensors

Science.gov (United States)

Duffy, Kirsten P.; Lerch, Bradley A.; Wilmoth, Nathan G.; Kray, Nicholas; Gemeinhardt, Gregory

2012-01-01

Piezoelectric materials have been proposed as a means of decreasing turbomachinery blade vibration either through a passive damping scheme, or as part of an active vibration control system. For polymer matrix fiber composite (PMFC) blades, the piezoelectric elements could be embedded within the blade material, protecting the brittle piezoceramic material from the airflow and from debris. Before implementation of a piezoelectric element within a PMFC blade, the effect on PMFC mechanical properties needs to be understood. This study attempts to determine how the inclusion of a packaged piezoelectric patch affects the material properties of the PMFC. Composite specimens with embedded piezoelectric patches were tested in four-point bending, short beam shear, and flatwise tension configurations. Results show that the embedded piezoelectric material does decrease the strength of the composite material, especially in flatwise tension, attributable to failure at the interface or within the piezoelectric element itself. In addition, the sensing properties of the post-cured embedded piezoelectric materials were tested, and performed as expected. The piezoelectric materials include a non-flexible patch incorporating solid piezoceramic material, and two flexible patch types incorporating piezoelectric fibers. The piezoceramic material used in these patches was Navy Type-II PZT.

Fast modal decomposition for optical fibers using digital holography.

Science.gov (United States)

Lyu, Meng; Lin, Zhiquan; Li, Guowei; Situ, Guohai

2017-07-26

Eigenmode decomposition of the light field at the output end of optical fibers can provide fundamental insights into the nature of electromagnetic-wave propagation through the fibers. Here we present a fast and complete modal decomposition technique for step-index optical fibers. The proposed technique employs digital holography to measure the light field at the output end of the multimode optical fiber, and utilizes the modal orthonormal property of the basis modes to calculate the modal coefficients of each mode. Optical experiments were carried out to demonstrate the proposed decomposition technique, showing that this approach is fast, accurate and cost-effective.

Short-pulse propagation in fiber optical parametric amplifiers

DEFF Research Database (Denmark)

Cristofori, Valentina

Fiber optical parametric amplifiers (FOPAs) are attractive because they can provide large gain over a broad range of central wavelengths, depending only on the availability of a suitable pump laser. In addition, FOPAs are suitable for the realization of all-optical signal processing functionalities...... transfer can be reduced in saturated F OPAs. In order to characterize propagation impairments such as dispersion and Kerr effect, affecting signals reaching multi-terabit per second per channel, short pulses on the order of 500 fs need to be considered. Therefore, a short pulses fiber laser source...... is implemented to obtain an all-fiber system. The advantages of all fiber-systems are related to their reliability, long-term stability and compactness. Fiber optical parametric chirped pulse amplification is promising for the amplification of such signals thanks to the inherent compatibility of FOPAs with fiber...

Fiber optic utilization at the Nevada Test Site

International Nuclear Information System (INIS)

Lyons, P.B.; Golob, J.E.; Looney, L.D.; Robichaud, R.E.; Nelson, M.A.; Davies, T.J.

1978-11-01

Optical fiber cables have been successfully used for 100-MHz analog data transmission during an underground nuclear test at the Nevada Test Site. Two 700-m Corning Corguide cables were used to provide thirteen single fiber data channels from the vicinity of the underground detonation, 350 meters below ground level, to recording instrumentation, 350 meters from the downhole shaft. No fiber performance degradation was observed during the extensive procedures used to seal the shaft. These procedures included backfilling the shaft with layers of sand and gravel, as well as poured epoxy plugs. Techniques were developed for internal sealing of the Corguide cable to prevent any possible radioactive gas flow through voids within the cable. The effects on optical fibers of intense, pulsed neutron and gamma irradiation were studied. Specialized tools, including a system for location of faults or breaks in the optical fibers, were developed. The success of this first test will allow consideration of fiber optic cables for future nuclear tests as well as for other applications involving extremely rough handling in field environments

Fiber optics principles and practices

CERN Document Server

Al-Azzawi, Abdul

2007-01-01

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

Fiber optics physics and technology

CERN Document Server

Mitschke, Fedor

2016-01-01

This book tells you all you want to know about optical fibers: Their structure, their light-guiding mechanism, their material and manufacture, their use. It began with telephone, then came telefax and email. Today we use search engines, music downloads and internet videos, all of which require shuffling of bits and bytes by the zillions. The key to all this is the conduit: the line which is designed to carry massive amounts of data at breakneck speed. In their data carrying capacity optical fiber lines beat all other technologies (copper cable, microwave beacons, satellite links) hands down, at least in the long haul; wireless devices rely on fibers, too. Several effects tend to degrade the signal as it travels down the fiber: they are spelled out in detail. Nonlinear processes are given due consideration for a twofold reason: On the one hand they are fundamentally different from the more familiar processes in electrical cable. On the other hand, they form the basis of particularly interesting and innovative ...

Fiber-Optic Sensor Facility

Data.gov (United States)

Federal Laboratory Consortium — FUNCTION: Constructs and evaluates fiber-optic sensors for a variety of measurands. These measurands include acoustic, pressure, magnetic, and electric field as well...

Nonlinear fiber optics

CERN Document Server

Agrawal, Govind

2012-01-01

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

Fuel level sensor based on polymer optical fiber Bragg gratings for aircraft applications

DEFF Research Database (Denmark)

Marques, C. A. F.; Pospori, A.; Sáez-Rodríguez, D.

2016-01-01

on capacitive, ultrasonic and electric techniques, however they suffer from intrinsic safety concerns in explosive environments combined with issues relating to reliability and maintainability. In the last few years, optical fiber liquid level sensors (OFLLSs) have been reported to be safe and reliable...... in diaphragms is investigated in detail. The mPOFBGs are embedded in two different types of diaphragms and their performance is investigated with aviation fuel for the first time, in contrast to our previous works, where water was used. Our new system exhibits a high performance when compared with other...

Respiratory monitoring system based on fiber optic macro bending

Science.gov (United States)

Purnamaningsih, Retno Wigajatri; Widyakinanti, Astari; Dhia, Arika; Gumelar, Muhammad Raditya; Widianto, Arif; Randy, Muhammad; Soedibyo, Harry