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Sample records for advanced fiber optic

  1. Advanced Optical Fiber Communication Systems

    DTIC Science & Technology

    1992-08-01

    Optical Network with Physical Star Topology," Advanced Fiber Communications Technologies , Leonid G. Kazovsky... advances in the performance and capabilities of optical fiber communication systems. While some of these technologies are interrelated (for example...multi gigabit per second hybrid circuit/packet switched lightwave network ," Proc. SPIE Advanced Fiber Communications Technologies , Boston 󈨟, Sept.

  2. Fiber optics for advanced aircraft

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert J.

    1988-01-01

    The increased use of composites makes the digital control more susceptible to electromagnetic effects. In order to provide the protection to the digital control additional shielding will be required as well as protective circuitry for the electronics. This results in increased weight and reduced reliability. The advantages that fiber optic technology provides for advanced aircraft applications is recognized. The use of optical signals to carry information between the aircraft and the control module provides immunity from contamination by electromagnetic sources as well as other important benefits such as reduced weight and volume resulting from the elimination of the shielding and the replacement of metal conductors with low weight glass fibers. In 1975 NASA began work to develop passive optical sensors for use with fiber optics in aircraft control systems. The problem now is to choose the best optical sensor concepts and evaluate them for use. In 1985 NASA and DOD entered into a joint program, Fiber Optic Control System Integration (FOCSI), to look at optical technology specifically for use in advanced aircraft systems. The results of this program are discussed. The conclusion of the study indicated that the use of fiber optic technology in advanced aircraft systems is feasible and desirable. The study pointed to a lack of available sensors from vendors capable of operating in the adverse environments of advanced aircraft.

  3. Fiber optics for advanced aircraft

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert J.

    1989-01-01

    The increased use of composites makes the digital control more susceptible to electromagnetic effects. In order to provide the protection to the digital control additional shielding will be required as well as protective circuitry for the electronics. This results in increased weight and reduced reliability. The advantages that fiber optic technology provides for advanced aircraft applications is recognized. The use of optical signals to carry information between the aircraft and the control module provides immunity from contamination by electromagnetic sources as well as other important benefits such as reduced weight and volume resulting from the elimination of the shielding and the replacement of metal conductors with low weight glass fibers. In 1975 NASA began work to develop passive optical sensors for use with fiber optics in aircraft control systems. The problem now is to choose the best optical sensor concepts and evaluate them for use. In 1985 NASA and DOD entered into a joint program, Fiber Optic Control System Integration (FOCSI), to look at optical technology specifically for use in advanced aircraft systems. The results of this program are discussed. The conclusion of the study indicated that the use of fiber optic technology in advanced aircraft systems is feasible and desirable. The study pointed to a lack of available sensors from vendors capable of operating in the adverse environments of advanced aircraft.

  4. Recent advancement in optical fiber sensing for aerospace composite structures

    NASA Astrophysics Data System (ADS)

    Minakuchi, Shu; Takeda, Nobuo

    2013-12-01

    Optical fiber sensors have attracted considerable attention in health monitoring of aerospace composite structures. This paper briefly reviews our recent advancement mainly in Brillouin-based distributed sensing. Damage detection, life cycle monitoring and shape reconstruction systems applicable to large-scale composite structures are presented, and new technical concepts, "smart crack arrester" and "hierarchical sensing system", are described as well, highlighting the great potential of optical fiber sensors for the structural health monitoring (SHM) field.

  5. Advances in sapphire optical fiber sensors

    NASA Technical Reports Server (NTRS)

    Wang, Anbo; Wang, George Z.; Gollapudi, Sridhar; May, Russell G.; Murphy, Kent A.; Claus, Richard O.

    1993-01-01

    We describe the development and testing of two sapphire fiber sensor designs intended for use in high temperature environments. The first is a birefringence-balanced polarimetric sapphire fiber sensor. In this sensor, two single crystal sapphire rods, acting as the birefringence sensing element, are connected to each other in such a way that the slow axis of the first rod is aligned along with the fast axis of the second rod, and the fast axis of the first rod is along the slow axis of the second rod. This sensor has been demonstrated for measurement of temperature up to 1500 C. The second is a sapphire-fiber-based intrinsic interferometric sensor. In this sensor, a length of uncoated, unclad, structural-graded multimode sapphire fiber is fusion spliced to a singlemode silica fiber to form a Fabry-Perot cavity. The reflections from the silica-to-sapphire fiber splice and the free endface of the sapphire fiber give rise to the interfering fringe output. This sensor has been demonstrated for the measurement of temperature above 1510 C, and a resolution of 0.1 C has been obtained.

  6. Catheters: instrumental advancements in biomedical applications of optical fibers.

    PubMed

    de Lima, Carlos J; Moreira, Leonardo M; Lyon, Juliana P; Villaverde, Antonio B; Pacheco, Marcos T T

    2009-07-01

    This review is focused on the advancements in biomedical engineering regarding the elaboration of new prototypes of optical fiber catheters to be applied in spectroscopic analysis, such as Raman and fluorescence spectroscopy. Our group has contributed to the development of new prototypes with interesting properties, such as side-viewing signal excitation and collection, distal tip with bending control, and Raman scattering minimization from the optical fiber. In addition, several groups have contributed to other new catheter-improving properties of this spectroscopic device. However, a relatively small number of studies has been published in the literature, due to industrial interest in this interdisciplinary and multidisciplinary area. To our knowledge, no review that has focused on the applications of catheters to several modes of spectroscopy has been published. In this work we revised this topic, analyzing the advancements and limitations of the recent biomedical catheters.

  7. Advances in optical fiber sensors for vehicle detection

    NASA Astrophysics Data System (ADS)

    Meller, Scott A.; de Vries, Marten J.; Arya, Vivek; Claus, Richard O.; Zabaronick, Noel

    1998-01-01

    THe primary objective for this project is the design of optical fiber-based sensor instrumentation for specific ITS applications. Specifically, this paper discusses research on optical fiber sensors that can be used for traffic monitoring and vehicle classification. This paper also discusses developments on the application of optical fiber sensor that can be used for monitoring visibility. This research is directly beneficial to the implementation of driver advisory and safety systems, traffic control system, and other ITS applications. This paper summarizes research performed on optical fiber sensors used for measuring traffic flow on highways and discusses progress on optical fiber sensors used for monitoring visibility.

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

    NASA Technical Reports Server (NTRS)

    1986-01-01

    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.

  9. Applications of advanced optical fiber sensors at UESTC

    NASA Astrophysics Data System (ADS)

    Rao, Yun-Jiang

    2012-02-01

    Based on many years research, a number of novel fiber-optic sensors and systems are developed by the Fiber Optics Group at University of Electronic Science & Technology of China (UESTC). This paper presents a review of the applications of these sensors and systems developed in recent years, including: (1) Micro fiber-optic Fabry-Perot interferometric sensors for high temperature strain measurement applications; (2) Fiber Bragg grating (FBG) sensors for safety monitoring applications in transportations industry; (3) Long-distance Brillouin optical time-domain analyzer (BOTDA) for high performance temperature/strain measurement; (4) Fiber-optic fences based on FBG and phasesensitive optical time-domain reflectometer (Φ-OTDR) for intrusion monitoring applications.

  10. Advances in fiber optic sensors for in-vivo monitoring

    NASA Astrophysics Data System (ADS)

    Baldini, Francesco; Mignani, Anna G.

    1995-09-01

    Biomedical fiber-optic sensors are attractive for the measurement of both physical and chemical parameters as well as for spectral measurements directly performed on the patient. An overview of fiber-optic sensors for in vivo monitoring is given, with particular attention to the advantages that these sensors are able to offer in different fields of application such as cardiovascular and intensive care, angiology, gastroenterology, ophthalmology, oncology, neurology, dermatology, and dentistry.

  11. Fiber optic (flight quality) sensors for advanced aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Poppel, Gary L.

    1994-01-01

    Development of flight prototype, fiber-optic sensing system components for measuring nine sensed parameters (three temperatures, two speeds, three positions, and one flame) on an F404-400 aircraft engine is described. Details of each sensor's design, functionality, and environmental testing, and the electro-optics architecture for sensor signal conditioning are presented. Eight different optical sensing techniques were utilized. Design, assembly, and environmental testing of an engine-mounted, electro-optics chassis unit (EOU), providing MIL-C-1553 data output, are related. Interconnection cables and connectors between the EOU and the sensors are identified. Results of sensor/cable/circuitry integrated testing, and installation and ground testing of the sensor system on an engine in October 1993 and April 1994 are given, including comparisons with the engine control system's electrical sensors. Lessons learned about the design, fabrication, testing, and integration of the sensor system components are included.

  12. Fiber Optic Surface Plasmon Resonance-Based Biosensor Technique: Fabrication, Advancement, and Application.

    PubMed

    Liang, Gaoling; Luo, Zewei; Liu, Kunping; Wang, Yimin; Dai, Jianxiong; Duan, Yixiang

    2016-05-03

    Fiber optic-based biosensors with surface plasmon resonance (SPR) technology are advanced label-free optical biosensing methods. They have brought tremendous progress in the sensing of various chemical and biological species. This review summarizes four sensing configurations (prism, grating, waveguide, and fiber optic) with two ways, attenuated total reflection (ATR) and diffraction, to excite the surface plasmons. Meanwhile, the designs of different probes (U-bent, tapered, and other probes) are also described. Finally, four major types of biosensors, immunosensor, DNA biosensor, enzyme biosensor, and living cell biosensor, are discussed in detail for their sensing principles and applications. Future prospects of fiber optic-based SPR sensor technology are discussed.

  13. Coherent Terahertz Wireless Signal Transmission Using Advanced Optical Fiber Communication Technology

    NASA Astrophysics Data System (ADS)

    Kanno, Atsushi; Kuri, Toshiaki; Morohashi, Isao; Hosako, Iwao; Kawanishi, Tetsuya; Yoshida, Yuki; Kitayama, Ken-ichi

    2015-02-01

    Coherent terahertz signal transmission with multilevel modulation and demodulation is demonstrated using an optical sub-harmonic IQ mixer (SHIQM), which consists of optical components in advanced optical fiber communication technologies. An optical-frequency-comb-employed signal generator is capable of vector modulation as well as frequency tunability. Digital signal processing (DSP) adopted from the recently developed optical digital coherent communication can easily demodulate multi-level modulated terahertz signals by using electrical heterodyning for intermediate-frequency (IF) down conversion. This technique is applicable for mobile backhauling in the next-generation mobile communication technology directly connected to an optical fiber network as a high-speed wireless transmission link.

  14. US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 3: Advanced networks and economics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This 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.

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

    SciTech Connect

    Hashemian, H.M.

    1996-03-01

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

  16. The fiber optic system for the advanced topographic laser altimeter system instrument (ATLAS)

    NASA Astrophysics Data System (ADS)

    Ott, Melanie N.; Thomes, W. Joe; Onuma, Eleanya; Switzer, Robert; Chuska, Richard; Blair, Diana; Frese, Erich; Matyseck, Marc

    2016-09-01

    The Advanced Topographic Laser Altimeter System (ATLAS) Instrument has been in integration and testing over the past 18 months in preparation for the Ice, Cloud and Land Elevation Satellite - 2 (ICESat-2) Mission, scheduled to launch in 2017. ICESat-2 is the follow on to ICESat which launched in 2003 and operated until 2009. ATLAS will measure the elevation of ice sheets, glaciers and sea ice or the "cryosphere" (as well as terrain) to provide data for assessing the earth's global climate changes. Where ICESat's instrument, the Geo-Science Laser Altimeter (GLAS) used a single beam measured with a 70 m spot on the ground and a distance between spots of 170 m, ATLAS will measure a spot size of 10 m with a spacing of 70 cm using six beams to measure terrain height changes as small as 4 mm.[1] The ATLAS pulsed transmission system consists of two lasers operating at 532 nm with transmitter optics for beam steering, a diffractive optical element that splits the signal into 6 separate beams, receivers for start pulse detection and a wavelength tracking system. The optical receiver telescope system consists of optics that focus all six beams into optical fibers that feed a filter system that transmits the signal via fiber assemblies to the detectors. Also included on the instrument is a system that calibrates the alignment of the transmitted pulses to the receiver optics for precise signal capture. The larger electro optical subsystems for transmission, calibration, and signal receive, stay aligned and transmitting sufficiently due to the optical fiber system that links them together. The robust design of the fiber optic system, consisting of a variety of multi fiber arrays and simplex assemblies with multiple fiber core sizes and types, will enable the system to maintain consistent critical alignments for the entire life of the mission. Some of the development approaches used to meet the challenging optical system requirements for ATLAS are discussed here.

  17. The fiber optic system for the Advanced Topographic Laser Altimeter System (ATLAS) instrument.

    PubMed

    Ott, Melanie N; Thomes, Joe; Onuma, Eleanya; Switzer, Robert; Chuska, Richard; Blair, Diana; Frese, Erich; Matyseck, Marc

    2016-08-28

    The Advanced Topographic Laser Altimeter System (ATLAS) Instrument has been in integration and testing over the past 18 months in preparation for the Ice, Cloud and Land Elevation Satellite - 2 (ICESat-2) Mission, scheduled to launch in 2017. ICESat-2 is the follow on to ICESat which launched in 2003 and operated until 2009. ATLAS will measure the elevation of ice sheets, glaciers and sea ice or the "cryosphere" (as well as terrain) to provide data for assessing the earth's global climate changes. Where ICESat's instrument, the Geo-Science Laser Altimeter (GLAS) used a single beam measured with a 70 m spot on the ground and a distance between spots of 170 m, ATLAS will measure a spot size of 10 m with a spacing of 70 cm using six beams to measure terrain height changes as small as 4 mm.[1] The ATLAS pulsed transmission system consists of two lasers operating at 532 nm with transmitter optics for beam steering, a diffractive optical element that splits the signal into 6 separate beams, receivers for start pulse detection and a wavelength tracking system. The optical receiver telescope system consists of optics that focus all six beams into optical fibers that feed a filter system that transmits the signal via fiber assemblies to the detectors. Also included on the instrument is a system that calibrates the alignment of the transmitted pulses to the receiver optics for precise signal capture. The larger electro optical subsystems for transmission, calibration, and signal receive, stay aligned and transmitting sufficiently due to the optical fiber system that links them together. The robust design of the fiber optic system, consisting of a variety of multi fiber arrays and simplex assemblies with multiple fiber core sizes and types, will enable the system to maintain consistent critical alignments for the entire life of the mission. Some of the development approaches used to meet the challenging optical system requirements for ATLAS are discussed here.

  18. Fiber-optic technologies for advanced thermo-therapy applied ex vivo to liver tumors

    NASA Astrophysics Data System (ADS)

    Tosi, D.; Perrone, G.; Vallan, A.; Braglia, A.; Liu, Y.; Macchi, E. G.; Braschi, G.; Gallati, M.; Cigada, A.; Poeggel, S.; Duraibabu, D. B.; Leen, G.; Lewis, E.

    2015-07-01

    Thermal ablation, using radiofrequency, microwave, and laser sources, is a common treatment for hepatic tumors. Sensors allow monitoring, at the point of treatment, the evolution of thermal ablation procedures. We present optical fiber sensors that allow advanced capabilities for recording the biophysical phenomena occurring in the tissue in real time. Distributed or quasi-distributed thermal sensors allow recording temperature with spatial resolution ranging from 0.1 mm to 5 mm. In addition, a thermally insensitive pressure sensor allows recording pressure rise, supporting advanced treatment of encapsulated tumors. Our investigation is focused on two case studies: (1) radiofrequency ablation of hepatic tissue, performed on a phantom with a stem-shaped applicator; (2) laser ablation of a liver phantom, performed with a fiber laser. The main measurement results are discussed, comparing the technologies used for the investigation, and drawing the potential for using optical fiber sensors for "smart"-ablation.

  19. Integrated optics for fiber optic sensors

    NASA Technical Reports Server (NTRS)

    Minford, W. J.; Depaula, R. P.

    1991-01-01

    Recent progress achieved in the field of fiber-optic sensor applications is discussed with emphasis placed on LiNbO3-based integrated optics (IO). Particular consideration is given to advanced electromagnetic-field sensors, an integrated laser vibrometer system, and a fiber-optic gyroscope system. It is shown that the multifunction IO chips have enabled high perforamance fiber-optic sensors (e.g., fiber-optic gyros), provided advanced and unique signal processing capabilities and advanced architectures, and have a potential of making fiber-optic sensors at low cost.

  20. Potential for integrated optical circuits in advanced aircraft with fiber optic control and monitoring systems

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert

    1991-01-01

    The current Fiber Optic Control System Integration (FOCSI) program is reviewed and the potential role of IOCs in FOCSI applications is described. The program is intended for building, environmentally testing, and demonstrating operation in piggyback flight tests (no active control with optical sensors) of a representative sensor system for propulsion and flight control. The optical sensor systems are to be designed to fit alongside the bill-of-materials sensors for comparison. The sensors are to be connected to electrooptic architecture cards which will contain the optical sources and detectors to recover and process the modulated optical signals. The FOCSI program is to collect data on the behavior of passive optical sensor systems in a flight environment and provide valuable information on installation amd maintenance problems for this technology, as well as component survivability (light sources, connectors, optical fibers, etc.).

  1. Advanced spectral fiber optic sensor systems and their application in energy facility monitoring

    NASA Astrophysics Data System (ADS)

    Willsch, Reinhardt; Ecke, Wolfgang; Bosselmann, Thomas; Willsch, Michael; Lindner, Eric; Bartelt, Hartmut

    2011-06-01

    Various spectral-encoded fiber optic sensor concepts and advanced system solutions for application in energy facility monitoring have been investigated. The technological maturity, high performance and reliability of multiplexed fiber Bragg grating (FBG) sensor arrays and networks for the measurement of temperature, dynamic strain, air flow, and magnetic field distributions in electric power generators increasing their efficiency will be demonstrated by selected examples of field testing under harsh environmental conditions. For high-temperature combustion monitoring in gas turbines, beside silica FBGs with enhanced temperature stability also sapphire FBGs and Fabry-Perot sensors have been tested and evaluated as well as fiber-based black-body thermal radiation sensors. Finally, the potential of FBG sensors for application in cryo-energetic facilities such as super-conductive high-power motors and experimental nuclear fusion reactors will be discussed.

  2. Fiber optics for controls

    NASA Technical Reports Server (NTRS)

    Seng, Gary T.

    1987-01-01

    The challenge of those involved in control-system hardware development is to accommodate an ever-increasing complexity in aircraft control, while limiting the size and weight of the components and improving system reliability. A technology that displays promise towards this end is the area of fiber optics for controls. The primary advantages of employing optical fibers, passive optical sensors, and optically controlled actuators are weight and volume reduction, immunity from electromagnetic effects, superior bandwidth capabilities, and freedom from short circuits and sparking contacts. Since 1975, NASA Lewis has performed in-house, contract, and grant research in fiber optic sensors, high-temperature electro-optic switches, and fly-by-light control-system architecture. Passive optical sensor development is an essential yet challenging area of work and has therefore received much attention during this period. A major effort to develop fly-by-light control-system technology, known as the Fiber-Optic Control System Integration (FOCSI) program, was initiated in 1985 as a cooperative effort between NASA and DOD. Phase 1 of FOCSI, completed in 1986, was aimed at the design of a fiber-optic integrated propulsion/flight control system. Phase 2, yet to be initiated, will provide subcomponent and system development, and a system engine test. In addition to a summary of the benefits of fiber optics, the FOCSI program, sensor advances, and future directions in the NASA Lewis program will be discussed.

  3. Fiber optic coupled optical sensor

    DOEpatents

    Fleming, Kevin J.

    2001-01-01

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

  4. Fiber Optic Microphone

    NASA Technical Reports Server (NTRS)

    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.

  5. Fiber optic monitoring device

    DOEpatents

    Samborsky, James K.

    1993-01-01

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

  6. Fiber optics for controls

    NASA Technical Reports Server (NTRS)

    Seng, Gary T.

    1990-01-01

    The design, development, and testing of a fiber optic integrated propulsion/flight control system for an advanced supersonic dash aircraft (flies at supersonic speeds for short periods of time) is the goal of the joint NASA/DOD Fiber Optic Control System Integration (FOCSI) program. Phase 1 provided a comparison of electronic and optical control systems, identified the status of current optical sensor technology, defined the aircraft sensor/actuator environment, proposed architectures for fully optical control systems, and provided schedules for development. Overall, it was determined that there are sufficient continued efforts to develop such a system. It was also determined that it is feasible to build a fiber optic control system for the development of a data base for this technology, but that further work is necessary in sensors, actuators, and components to develop an optimum design, fully fiber optic integrated control system compatible with advanced aircraft environments. Phase 2 is to design, construct, and ground test a fly by light control system. Its first task is to provide a detailed design of the electro-optic architecture.

  7. Advanced Optical Fiber Development for kW Fiber Lasers with Sub-GHz Linewidth

    DTIC Science & Technology

    2016-01-12

    better atmosphere transmissions and eye -safe characteristics. This capability is also critical for the hollow-core fiber developments in our current...power potentials, better atmosphere transmissions and eye -safe characteristics. This capability is also critical for the hollow-core fiber

  8. US long distance fiber optic networks: Technology, evolution and advanced concepts. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Over the past two decades, fiber optics has emerged as a highly practical and cost-efficient communications technology. Its competitiveness vis-a-vis other transmission media, especially satellite, has become a critical question. This report studies the likely evolution and application of fiber optic networks in the United States to the end of the century. The outlook for the technology of fiber systems is assessed and forecast, scenarios of the evolution of fiber optic network development are constructed, and costs to provide service are determined and examined parametrically as a function of network size and traffic carried. Volume 1 consists of the Executive Summary. Volume 2 focuses on fiber optic technology and long distance fiber optic networks. Volume 3 develops a traffic and financial model of a nationwide long distance transmission network. Among the study's most important conclusions are: revenue requirements per circuit for LATA-to-LATA fiber optic links are less than one cent per call minute; multiplex equipment, which is likely to be required in any competing system, is the largest contributor to circuit costs; the potential capacity of fiber optic cable is very large and as yet undefined; and fiber optic transmission combined with other network optimization schemes can lead to even lower costs than those identified in this study.

  9. Multiplexed Optical Fiber Sensors for Coal Fired Advanced Fossil Energy Systems

    SciTech Connect

    Wang, Anbo; Pickrell, Gary

    2012-03-31

    This report summarizes technical progress on the program Multiplexed Optical Fiber Sensors for Coal Fired Advanced Fossil Energy Systems funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed jointly by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering and the Department of Materials Science and Engineering at Virginia Tech. This three-year project started on October 1, 2008. In the project, a fiber optical sensing system based on intrinsic Fabry-Perot Interferometer (IFPI) was developed for strain and temperature measurements for Ultra Supercritical boiler condition assessment. Investigations were focused on sensor design, fabrication, attachment techniques and novel materials for high temperature and strain measurements. At the start of the project, the technical requirements for the sensing technology were determined together with our industrial partner Alstom Power. As is demonstrated in Chapter 4, all the technical requirements are successfully met. The success of the technology extended beyond laboratory test; its capability was further validated through the field test at DOE NETL, in which the sensors yielded distributed temperature mapping of a testing coupon installed in the turbine test rig. The measurement results agreed well with prior results generated with thermocouples. In this project, significant improvements were made to the IFPI sensor technology by splicing condition optimization, transmission loss reduction, sensor signal demodulation and sensor system design.

  10. Fiber optic connector

    DOEpatents

    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.

  11. Fiber optic temperature sensor

    NASA Technical Reports Server (NTRS)

    Sawatari, Takeo (Inventor); Gaubis, Philip A. (Inventor)

    2000-01-01

    A fiber optic temperature sensor uses a light source which transmits light through an optical fiber to a sensor head at the opposite end of the optical fiber from the light source. The sensor head has a housing coupled to the end of the optical fiber. A metallic reflective surface is coupled to the housing adjacent the end of the optical fiber to form a gap having a predetermined length between the reflective surface and the optical fiber. A detection system is also coupled to the optical fiber which determines the temperature at the sensor head from an interference pattern of light which is reflected from the reflective surface.

  12. Fiber optic temperature sensor

    NASA Technical Reports Server (NTRS)

    Sawatari, Takeo (Inventor); Gaubis, Philip A. (Inventor); Mattes, Brenton L. (Inventor); Charnetski, Clark J. (Inventor)

    1999-01-01

    A fiber optic temperature sensor uses a light source which transmits light through an optical fiber to a sensor head at the opposite end of the optical fiber from the light source. The sensor head has a housing coupled to the end of the optical fiber. A metallic reflective surface is coupled to the housing adjacent the end of the optical fiber to form a gap having a predetermined length between the reflective surface and the optical fiber. A detection system is also coupled to the optical fiber which determines the temperature at the sensor head from an interference pattern of light which is reflected from the reflective surface.

  13. Fiber optic connector

    DOEpatents

    Rajic, S.; Muhs, J.D.

    1996-10-22

    A fiber optic connector and method for connecting composite materials within which optical fibers are imbedded are disclosed. 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. 3 figs.

  14. An ultrafast optics undergraduate advanced laboratory with a mode-locked fiber laser

    NASA Astrophysics Data System (ADS)

    Schaffer, Andrew; Fredrick, Connor; Hoyt, Chad; Jones, Jason

    2015-05-01

    We describe an ultrafast optics undergraduate advanced laboratory comprising a mode-locked erbium fiber laser, auto-correlation measurements, and an external, free-space parallel grating dispersion compensation apparatus. The simple design of the stretched pulse laser uses nonlinear polarization rotation mode-locking to produce pulses at a repetition rate of 55 MHz and average power of 5.5 mW. Interferometric and intensity auto-correlation measurements are made using a Michelson interferometer that takes advantage of the two-photon nonlinear response of a common silicon photodiode for the second order correlation between 1550 nm laser pulses. After a pre-amplifier and compression, pulse widths as narrow as 108 fs are measured at 17 mW average power. A detailed parts list includes previously owned and common components used by the telecommunications industry, which may decrease the cost of the lab to within reach of many undergraduate and graduate departments. We also describe progress toward a relatively low-cost optical frequency comb advanced laboratory. NSF EIR #1208930.

  15. Development of fiber optic sensors for advanced aircraft testing and control

    NASA Astrophysics Data System (ADS)

    Meller, Scott A.; Jones, Mark E.; Wavering, Thomas A.; Kozikowski, Carrie L.; Murphy, Kent A.

    1999-02-01

    Optical fiber sensors, because of the small size, low weight, extremely high information carrying capability, immunity to electromagnetic interference, and large operational temperature range, provide numerous advantages over conventional electrically based sensors. This paper presents preliminary results from optical fiber sensor design for monitoring acceleration on aircraft. Flight testing of the final accelerometer design will be conducted on the F-18 Systems Research Aircraft at NASA Dryden Flight Research Center in Edwards, CA.

  16. Advanced Engineering Fibers.

    ERIC Educational Resources Information Center

    Edie, Dan D.; Dunham, Michael G.

    1987-01-01

    Describes Clemson University's Advanced Engineered Fibers Laboratory, which was established to provide national leadership and expertise in developing the processing equipment and advance fibers necessary for the chemical, fiber, and textile industries to enter the composite materials market. Discusses some of the laboratory's activities in…

  17. Fiber optic control system integration

    NASA Technical Reports Server (NTRS)

    Poppel, G. L.; Glasheen, W. M.; Russell, J. C.

    1987-01-01

    A total fiber optic, integrated propulsion/flight control system concept for advanced fighter aircraft is presented. Fiber optic technology pertaining to this system is identified and evaluated for application readiness. A fiber optic sensor vendor survey was completed, and the results are reported. The advantages of centralized/direct architecture are reviewed, and the concept of the protocol branch is explained. Preliminary protocol branch selections are made based on the F-18/F404 application. Concepts for new optical tools are described. Development plans for the optical technology and the described system are included.

  18. Fiber optic monitoring device

    DOEpatents

    Samborsky, J.K.

    1993-10-05

    A device for the purpose of monitoring light transmissions in optical fibers comprises a fiber optic tap that optically diverts a fraction of a transmitted optical signal without disrupting the integrity of the signal. The diverted signal is carried, preferably by the fiber optic tap, to a lens or lens system that disperses the light over a solid angle that facilitates viewing. The dispersed light indicates whether or not the monitored optical fiber or system of optical fibers is currently transmitting optical information. 4 figures.

  19. Advanced Interrogation of Fiber-Optic Bragg Grating and Fabry-Perot Sensors with KLT Analysis

    PubMed Central

    Tosi, Daniele

    2015-01-01

    The Karhunen-Loeve Transform (KLT) is applied to accurate detection of optical fiber sensors in the spectral domain. By processing an optical spectrum, although coarsely sampled, through the KLT, and subsequently processing the obtained eigenvalues, it is possible to decode a plurality of optical sensor results. The KLT returns higher accuracy than other demodulation techniques, despite coarse sampling, and exhibits higher resilience to noise. Three case studies of KLT-based processing are presented, representing most of the current challenges in optical fiber sensing: (1) demodulation of individual sensors, such as Fiber Bragg Gratings (FBGs) and Fabry-Perot Interferometers (FPIs); (2) demodulation of dual (FBG/FPI) sensors; (3) application of reverse KLT to isolate different sensors operating on the same spectrum. A simulative outline is provided to demonstrate the KLT operation and estimate performance; a brief experimental section is also provided to validate accurate FBG and FPI decoding. PMID:26528975

  20. Advanced Interrogation of Fiber-Optic Bragg Grating and Fabry-Perot Sensors with KLT Analysis.

    PubMed

    Tosi, Daniele

    2015-10-29

    The Karhunen-Loeve Transform (KLT) is applied to accurate detection of optical fiber sensors in the spectral domain. By processing an optical spectrum, although coarsely sampled, through the KLT, and subsequently processing the obtained eigenvalues, it is possible to decode a plurality of optical sensor results. The KLT returns higher accuracy than other demodulation techniques, despite coarse sampling, and exhibits higher resilience to noise. Three case studies of KLT-based processing are presented, representing most of the current challenges in optical fiber sensing: (1) demodulation of individual sensors, such as Fiber Bragg Gratings (FBGs) and Fabry-Perot Interferometers (FPIs); (2) demodulation of dual (FBG/FPI) sensors; (3) application of reverse KLT to isolate different sensors operating on the same spectrum. A simulative outline is provided to demonstrate the KLT operation and estimate performance; a brief experimental section is also provided to validate accurate FBG and FPI decoding.

  1. Infrared Fiber Optic Sensors

    NASA Technical Reports Server (NTRS)

    1997-01-01

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

  2. Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems

    SciTech Connect

    Pickrell, Gary; Scott, Brian

    2014-06-30

    This report covers the technical progress on the program “Novel Modified Optical Fibers for High Temperature In-Situ Miniaturized Gas Sensors in Advanced Fossil Energy Systems”, funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Materials Science & Engineering and Electrical & Computer Engineering Departments at Virginia Tech, and summarizes technical progress from July 1st, 2005 –June 30th, 2014. The objective of this program was to develop novel fiber materials for high temperature gas sensors based on evanescent wave absorption in optical fibers. This project focused on two primary areas: the study of a sapphire photonic crystal fiber (SPCF) for operation at high temperature and long wavelengths, and a porous glass based fiber optic sensor for gas detection. The sapphire component of the project focused on the development of a sapphire photonic crystal fiber, modeling of the new structures, fabrication of the optimal structure, development of a long wavelength interrogation system, testing of the optical properties, and gas and temperature testing of the final sensor. The fabrication of the 6 rod SPCF gap bundle (diameter of 70μm) with a hollow core was successfully constructed with lead-in and lead-out 50μm diameter fiber along with transmission and gas detection testing. Testing of the sapphire photonic crystal fiber sensor capabilities with the developed long wavelength optical system showed the ability to detect CO2 at or below 1000ppm at temperatures up to 1000°C. Work on the porous glass sensor focused on the development of a porous clad solid core optical fiber, a hollow core waveguide, gas detection capabilities at room and high temperature, simultaneous gas species detection, suitable joining technologies for the lead-in and lead-out fibers and the porous sensor, sensor system sensitivity improvement, signal processing improvement, relationship between pore structure and fiber

  3. Fiber Optics Instrumentation Development

    NASA Technical Reports Server (NTRS)

    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.

  4. Fiber Optics Technology.

    ERIC Educational Resources Information Center

    Burns, William E.

    1986-01-01

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

  5. Fiber optic sensors

    NASA Technical Reports Server (NTRS)

    Hesse, J.; Sohler, W.

    1984-01-01

    A survey of the developments in the field of fiber optics sensor technology is presented along with a discussion of the advantages of optical measuring instruments as compared with electronic sensors. The two primary types of fiber optics sensors, specifically those with multiwave fibers and those with monowave fibers, are described. Examples of each major sensor type are presented and discussed. Multiwave detectors include external and internal fiber optics sensors. Among the monowave detectors are Mach-Zender interferometers, Michelson interferometers, Sagnac interferometers (optical gyroscopes), waveguide resonators, and polarimeter sensors. Integrated optical sensors and their application in spectroscopy are briefly discussed.

  6. Advanced Fiber-optic Monitoring System for Space-flight Applications

    NASA Technical Reports Server (NTRS)

    Hull, M. S.; VanTassell, R. L.; Pennington, C. D.; Roman, M.

    2005-01-01

    Researchers at Luna Innovations Inc. and the National Aeronautic and Space Administration s Marshall Space Flight Center (NASA MSFC) have developed an integrated fiber-optic sensor system for real-time monitoring of chemical contaminants and whole-cell bacterial pathogens in water. The system integrates interferometric and evanescent-wave optical fiber-based sensing methodologies with atomic force microscopy (AFM) and long-period grating (LPG) technology to provide versatile measurement capability for both micro- and nano-scale analytes. Sensors can be multiplexed in an array format and embedded in a totally self-contained laboratory card for use with an automated microfluidics platform.

  7. Two Fiber Optical Fiber Thermometry

    NASA Technical Reports Server (NTRS)

    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.

  8. Omnidirectional fiber optic tiltmeter

    DOEpatents

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

    1983-06-30

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

  9. Recent advances in fiber optics components for high speed data transmission

    NASA Astrophysics Data System (ADS)

    Leskovar, B.

    1991-04-01

    The concept of guided lightwave communication along optical fibers has stimulated a major new technology over the past two decades. This technology profoundly impacts communication and instrumentation systems as well as computer interconnections and systems architecture. In this paper, the state of the art of optical transmitters, low loss fiber waveguides, receivers, and associated electronics components are reviewed and summarized for optical data transmission systems operating between 100 Mbit/s and 2.5 Gbit/s. Emphasis is placed on high speed data transmission subassemblies, such as time division multiplexers and demultiplexers, clock and data recovery circuits, as well as optical transmitters and receivers. In addition, the performance of candidate components of the wide band digital transmission systems intended for deployment in large detection systems for particle physics is discussed.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  11. Influence of Embedded Optical Fibers on Compressive Strength of Advanced Composites

    DTIC Science & Technology

    1993-12-01

    3501-6 (graphite/epoxy) laminate embedded with several variations of optical fiber size, number, and orientation within the structure. Results showed...Test Fixture ..................................................................... 22 2.7 Classical Laminated Plate Theory... Laminate Euler Buckling Stress ................................ 91 Appendix B: Calculations for Classical Laminated Plate Theory

  12. Fiber optic vibration sensor

    DOEpatents

    Dooley, J.B.; Muhs, J.D.; Tobin, K.W.

    1995-01-10

    A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity. 2 figures.

  13. Fiber optic vibration sensor

    DOEpatents

    Dooley, Joseph B.; Muhs, Jeffrey D.; Tobin, Kenneth W.

    1995-01-01

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

  14. Small Business Innovations (Fiber Optics)

    NASA Technical Reports Server (NTRS)

    1991-01-01

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

  15. Distributed Brillouin fiber optic strain monitoring applications in advanced composite materials

    NASA Astrophysics Data System (ADS)

    Bastianini, Filippo; Cargnelutti, Mario; Di Tommaso, Angelo; Toffanin, Massimo

    2003-08-01

    Composite materials based on glass, carbon and aramid fibers have many advantages such as fast application, lightweight and corrosion resistance, and are widely diffused for manufacturing of tanks, pipings and for restoration, upgrade and seismic retrofit of structures and historical heritage. As several questions regarding long term durability of composite strengthenings remains still unsolved, monitoring of strain and temperature is strongly recommended, respectively to assess proper load transfer and no glass phase transition of the polymeric matrix. In this research work strain and temperature distributed sensing trough Brillouin scattering in single-mode optical fibers was used in different tests in order to understand the influence of different fiber coatings and embedding techniques. Pressure tests were performed on a GFRP piping with inhomogeneous strengthening layout and Brillouin strain data were compared with conventional strain gages. A smart CFRP material has been also developed and evaluated in a seismic retrofit application on an historical building dated 1500 that was seriously damaged in the earthquake of 1997. The developed embedding technique has been demonstrated successful to obtain fiber-optic smart composites with low optical losses, and the data comparison between Brillouin and resistive strain gauges confirms Brillouin technique is very effective for composite monitoring.

  16. Fiber optic micro accelerometer

    DOEpatents

    Swierkowski, Steve P.

    2005-07-26

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

  17. The Fiber Optic Connection.

    ERIC Educational Resources Information Center

    Reese, Susan

    2003-01-01

    Describes the fiber optics programs at the Career and Technical Center in Berlin, Pennsylvania and the Charles S. Monroe Technology Center in Loudoun County, Virginia. Discusses the involvement of the Fiber Optic Association with education, research and development, manufacturing, sales, distribution, installation, and maintenance of fiber optic…

  18. Remote optical fiber dosimetry

    NASA Astrophysics Data System (ADS)

    Huston, A. L.; Justus, B. L.; Falkenstein, P. L.; Miller, R. W.; Ning, H.; Altemus, R.

    2001-09-01

    Optical fibers offer a unique capability for remote monitoring of radiation in difficult-to-access and/or hazardous locations. Optical fiber sensors can be located in radiation hazardous areas and optically interrogated from a safe distance. A variety of remote optical fiber radiation dosimetry methods have been developed. All of the methods take advantage of some form of radiation-induced change in the optical properties of materials such as: radiation-induced darkening due to defect formation in glasses, luminescence from native defects or radiation-induced defects, or population of metastable charge trapping centers. Optical attenuation techniques are used to measure radiation-induced darkening in fibers. Luminescence techniques include the direct measurement of scintillation or optical excitation of radiation-induced luminescent defects. Optical fiber radiation dosimeters have also been constructed using charge trapping materials that exhibit thermoluminescence or optically stimulated luminescence (OSL).

  19. Study of Extra-Solar Planets with the Advanced Fiber Optic Echelle

    NASA Technical Reports Server (NTRS)

    Noyes, Robert W.; Boyce, Joseph M. (Technical Monitor)

    2002-01-01

    This is the final report of NASA Grant NAG5-7505, for 'Study of Extra-solar Planets with the Advanced Fiber Optic Echelle'. This program was funded in response to our proposal submitted under NASA NRA 97-OSS-06, with a total period of performance from June 1, 1998 through Feb 28 2002. Principal Investigator is Robert W. Noyes; co-Investigators are Sylvain G. Korzennik (SAO), Peter Niserison (SAO), and Timothy M. Brown (High Altitude Observatory). Since the start of this program we have carried out more than 30 observing runs, typically of 5 to 7 days duration. We obtained a total of around 2000 usable observations of about 150 stars, where a typical observation consists of 3 exposures of 10 minutes each. Using this data base we detected thc two additional planetary companions to the star Upsilon Andromedae. This detection was made independently of, and essentially simultaneously with, a similar detection by the Berkeley group (Marcy et al): the fact that two data sets were completely independent and gave essentially the same orbital parameters for this three-planet system gave a strong confirmation of this important result. We also extended our previous detection of the planet orbiting Rho Coronae Borealis to get a better determination of its orbital eccentricity: e=0.13 +/- 0.05. We detected a new planet in orbit around the star HD 89744, with orbital period 256 days, semi-major axis 0.88 AU, eccentricity 0.70, and minimum mass m sini = 7.2 m(sub Jup). This discovery is significant because of the very high orbital eccentricity, arid also because HD 89744 has both high metallicity [Fe/H] and at the same time a low [C/Fe] abundance ratio.

  20. Overview of advanced fiber optic sensor equipment for energy production applications

    NASA Astrophysics Data System (ADS)

    Berthold, John W.; Lopushansky, Richard L.

    2004-12-01

    Over the last several years, fiber optic sensor technology has matured to the point that it is now ready for use in industrial applications. Fiber optic sensors have the potential for significant cost savings to the customer, primarily because installation is straightforward and maintenance is minimal. Substantial improvements in the performance of process control systems are a major benefit that has now been demonstrated and is now understood by many in the energy and petrochemical industries. This paper describes the basic principles and components that make up an industrial fiber optic sensing system, the results of an extensive characterization program performed on Fabry-Perot sensors configured to measure various parameters, the multiplexing approach for a multi-sensor system, data communications options, and potential applications of the technology within the industry. The results of a beta test program performed on a thirty-two channel temperature measurement system are reported also. The test program was conducted in an operating catalyst tube reactor to measure changes in the reactor temperature profile versus time.

  1. Fiber optic laser rod

    DOEpatents

    Erickson, G.F.

    1988-04-13

    A laser rod is formed from a plurality of optical fibers, each forming an individual laser. Synchronization of the individual fiber lasers is obtained by evanescent wave coupling between adjacent optical fiber cores. The fiber cores are dye-doped and spaced at a distance appropriate for evanescent wave coupling at the wavelength of the selected dye. An interstitial material having an index of refraction lower than that of the fiber core provides the optical isolation for effective lasing action while maintaining the cores at the appropriate coupling distance. 2 figs.

  2. Fiber Optic Feed

    DTIC Science & Technology

    1990-11-06

    Naval Research Laboratory IIK Washington, DC,20375 5000 NRL Memorandum Report 6741 0 N Fiber Optic Feed DENZIL STILWELL, MARK PARENT AND LEw GOLDBERG...SUBTITLE S. FUNDING NUMBERS Fiber Optic Feed 53-0611-A0 6. AUTHOR(S) P. D. Stilwell, M. G. Parent, L. Goldberg 7. PERFORMING ORGANIZATION NAME(S) AND...DISTRIBUTION CODE Approved for public release; distribution unlimited. 13. ABSTRACT (Maximum 200 words) This report details a Fiber Optic Feeding

  3. Application of Fiber Optic Instrumentation

    NASA Technical Reports Server (NTRS)

    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.

  4. Multimode optical fiber

    SciTech Connect

    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).

  5. Fiber optic hydrophone

    DOEpatents

    Kuzmenko, P.J.; Davis, D.T.

    1994-05-10

    A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer is disclosed. 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 optical 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. 2 figures.

  6. Fiber optic hydrophone

    DOEpatents

    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.

  7. Woven fiber optics.

    PubMed

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

    1975-02-01

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

  8. Python fiber optic seal

    SciTech Connect

    Ystesund, K.; Bartberger, J.; Brusseau, C.; Fleming, P.; Insch, K.; Tolk, K.

    1993-08-01

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

  9. Characterization of embedded fiber optic sensors in advanced composite materials for structural health monitoring

    NASA Astrophysics Data System (ADS)

    Richards, W. L.; Lee, Dong Gun; Piazza, Anthony; Stewart, Anna K.; Carman, Gregory P.

    2004-07-01

    This paper presents comprehensive studies on sensor performance of an embedded Extrinsic Fabry Perot Interferometer (EFPI) fiber optic strain sensor in an aerospace grade composite system to support fiber optic smart structures (FOSS) development for Structural Health Monitoring (SHM) System. A major portion of this study is focused on establishing the accuracy of the embedded EFPI sensors in a graphite epoxy composite material system at different stress levels under quasi-static loading conditions. The NASA Dryden calibrated EFPI's were used for accurate measurements. Two collocated surface-mounted strain gages and a calibrated surface-mounted EFPI sensor are used to validate the calibrated embedded EFPI sensor. Experimental results suggest that once calibrated, the embedded and surface-mounted EFPI sensors provide robust, reliable and accurate measurement for values up to ~5,400 μɛ higher than sensor's durability limit ~3,000 μɛ at 106 cycles. This validation provides evidence that the sensing information emanating from FOSS can be used to monitor accurate health information.

  10. Optical fiber evanescent wave adsorption sensors for high-temperature gas sensing in advanced coal-fired power plants

    SciTech Connect

    Buric, M.; Ohodnicky, P.; Duy, J.

    2012-01-01

    Modern advanced energy systems such as coal-fired power plants, gasifiers, or similar infrastructure present some of the most challenging harsh environments for sensors. The power industry would benefit from new, ultra-high temperature devices capable of surviving in hot and corrosive environments for embedded sensing at the highest value locations. For these applications, we are currently exploring optical fiber evanescent wave absorption spectroscopy (EWAS) based sensors consisting of high temperature core materials integrated with novel high temperature gas sensitive cladding materials. Mathematical simulations can be used to assist in sensor development efforts, and we describe a simulation code that assumes a single thick cladding layer with gas sensitive optical constants. Recent work has demonstrated that Au nanoparticle-incorporated metal oxides show a potentially useful response for high temperature optical gas sensing applications through the sensitivity of the localized surface plasmon resonance absorption peak to ambient atmospheric conditions. Hence, the simulation code has been applied to understand how such a response can be exploited in an optical fiber based EWAS sensor configuration. We demonstrate that interrogation can be used to optimize the sensing response in such materials.

  11. Infrared fiber optic materials

    NASA Technical Reports Server (NTRS)

    Feigelson, Robert S.

    1987-01-01

    The development of IR fiber optics for use in astronomical and other space applications is summarized. Candidate materials were sought for use in the 1 to 200 micron and the 200 to 1000 micron wavelength range. Synthesis and optical characterization were carried out on several of these materials in bulk form. And the fabrication of a few materials in single crystal fiber optic form were studied.

  12. Fiber optic moisture sensor

    DOEpatents

    Kirkham, R.R.

    1984-08-03

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

  13. Optical pulse generation using fiber lasers and integrated optics

    SciTech Connect

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

    1995-03-27

    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.

  14. Optical fiber metamagnetics.

    PubMed

    Wang, Xi; Venugopal, Gayatri; Zeng, Jinwei; Chen, Yinnan; Lee, Dong Ho; Litchinitser, Natalia M; Cartwright, Alexander N

    2011-10-10

    To date, magnetic and negative-index metamaterials at optical frequencies were realized on bulk substrates in the form of thin films with thicknesses on the order of, or less than, optical wavelengths. In this work, we design and experimentally demonstrate, for the first time, fiber-coupled magnetic metamaterials integrated on the transverse cross-section of an optical fiber. Such fiber-metamaterials integration may provide fundamentally new solutions for photonic-on-a-chip systems for sensing, subwavelength imaging, image processing, and biomedical applications.

  15. Fiber Optics: No Illusion.

    ERIC Educational Resources Information Center

    American School and University, 1983

    1983-01-01

    A campus computer center at Hofstra University (New York) that holds 70 terminals for student use was first a gymnasium, then a language laboratory. Strands of fiber optics are used for the necessary wiring. (MLF)

  16. Simulating Optical Fibers.

    ERIC Educational Resources Information Center

    Edgar, Dale

    1988-01-01

    Described is a demonstration of Snell's law using a laser beam and an optical fiber. Provided are the set-up method of the demonstration apparatus and some practical suggestions including "index matching" technique using vaseline. (YP)

  17. Fiber optics: A research paper

    NASA Technical Reports Server (NTRS)

    Drone, Melinda M.

    1987-01-01

    Some basic aspects concerning fiber optics are examined. Some history leading up to the development of optical fibers which are now used in the transmission of data in many areas of the world is discussed. Basic theory of the operation of fiber optics is discussed along with methods for improving performance of the optical fiber through much research and design. Splices and connectors are compared and short haul and long haul fiber optic networks are discussed. Fiber optics plays many roles in the commercial world. The use of fiber optics for communication applications is emphasized.

  18. Fiber optics: A research paper

    NASA Astrophysics Data System (ADS)

    Drone, Melinda M.

    1987-08-01

    Some basic aspects concerning fiber optics are examined. Some history leading up to the development of optical fibers which are now used in the transmission of data in many areas of the world is discussed. Basic theory of the operation of fiber optics is discussed along with methods for improving performance of the optical fiber through much research and design. Splices and connectors are compared and short haul and long haul fiber optic networks are discussed. Fiber optics plays many roles in the commercial world. The use of fiber optics for communication applications is emphasized.

  19. Fiber optic hydrogen sensor

    DOEpatents

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

    1991-01-01

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

  20. Fiber optic hydrogen sensor

    DOEpatents

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

    1992-10-06

    An apparatus and method are described for detecting a chemical substance by exposing an optic fiber having a core and a cladding to the chemical substance so that the chemical substance can be adsorbed onto the surface of the cladding. The optic fiber is coiled inside a container having a pair of valves for controlling the entrance and exit of the substance. Light from a light source is received by one end of the optic fiber, preferably external to the container, and carried by the core of the fiber. Adsorbed substance changes the transmissivity of the fiber as measured by a spectrophotometer at the other end, also preferably external to the container. Hydrogen is detected by the absorption of infrared light carried by an optic fiber with a silica cladding. Since the adsorption is reversible, a sensor according to the present invention can be used repeatedly. Multiple positions in a process system can be monitored using a single container that can be connected to each location to be monitored so that a sample can be obtained for measurement, or, alternatively, containers can be placed near each position and the optic fibers carrying the partially-absorbed light can be multiplexed for rapid sequential reading by a single spectrophotometer. 4 figs.

  1. Fiber optic hydrogen sensor

    DOEpatents

    Buchanan, Bruce R.; Prather, William S.

    1992-01-01

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

  2. Fiber optics welder

    DOEpatents

    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.

  3. Fiber optic detector

    NASA Astrophysics Data System (ADS)

    Partin, Judy K.; Ward, Thomas E.; Grey, Alan E.

    1990-04-01

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

  4. Fiber optic detector

    SciTech Connect

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

    1990-12-31

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

  5. Optical fiber phase discriminator.

    PubMed

    Danielson, B L

    1978-11-15

    Phase discriminators are devices widely used at rf and microwave frequencies to convert phase, or frequency, changes to amplitude changes. They find widespread use in generating audio feedback signals for frequency stabilization of oscillators and in angle demodulation applications. This paper demonstrates that similar devices, with similar functions, can be constructed in the visible region using optical fibers as delay-line elements. The operating principles of an optical-fiber delay-line phase discriminator are discussed. The sensitivity is shown to be proportional to the fiber propagation-delay time. A device working at 0.6328 microm is described and compared with predictions.

  6. Splicing plastic optical fibers

    NASA Astrophysics Data System (ADS)

    Carson, Susan D.; Salazar, Roberto A.

    1991-12-01

    Polymethylmethacrylate (PMMA) plastic optical fiber (500 micrometers diameter, fluoropolymer cladding) has been spliced using a fused silica sleeve and a variety of solvent/PMMA solutions as adhesives. Mechanical splicing using index matching fluid has also been investigated. To ensure good bonding and minimize scattering, fiber ends are polished prior to application of adhesive. Using an LED ((lambda) max approximately 640 nm), losses are routinely less than 1.0 dB/splice, and some adhesive formulations have exhibited losses as low as 0.2 dB/splice. Five-meter fibers with as many as ten splices/fiber have been monitored over a period of several months. No fiber has exhibited an increase in optical loss with time.

  7. Silicon fiber optic sensors

    DOEpatents

    Pocha, Michael D.; Swierkowski, Steve P.; Wood, Billy E.

    2007-10-02

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

  8. Advanced optical instruments technology

    NASA Technical Reports Server (NTRS)

    Shao, Mike; Chrisp, Michael; Cheng, Li-Jen; Eng, Sverre; Glavich, Thomas; Goad, Larry; Jones, Bill; Kaarat, Philip; Nein, Max; Robinson, William

    1992-01-01

    The science objectives for proposed NASA missions for the next decades push the state of the art in sensitivity and spatial resolution over a wide range of wavelengths, including the x-ray to the submillimeter. While some of the proposed missions are larger and more sensitive versions of familiar concepts, such as the next generation space telescope, others use concepts, common on the Earth, but new to space, such as optical interferometry, in order to provide spatial resolutions impossible with other concepts. However, despite their architecture, the performance of all of the proposed missions depends critically on the back-end instruments that process the collected energy to produce scientifically interesting outputs. The Advanced Optical Instruments Technology panel was chartered with defining technology development plans that would best improve optical instrument performance for future astrophysics missions. At this workshop the optical instrument was defined as the set of optical components that reimage the light from the telescope onto the detectors to provide information about the spatial, spectral, and polarization properties of the light. This definition was used to distinguish the optical instrument technology issues from those associated with the telescope, which were covered by a separate panel. The panel identified several areas for optical component technology development: diffraction gratings; tunable filters; interferometric beam combiners; optical materials; and fiber optics. The panel also determined that stray light suppression instruments, such as coronagraphs and nulling interferometers, were in need of general development to support future astrophysics needs.

  9. Optical fiber switch

    DOEpatents

    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.

  10. Electrospun Amplified Fiber Optics

    PubMed Central

    2015-01-01

    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. PMID:25710188

  11. Electrospun amplified fiber optics.

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  13. Advanced radio over fiber network technologies.

    PubMed

    Novak, Dalma; Waterhouse, Rod

    2013-09-23

    The evolution of wireless communication networks supporting emerging broadband services and applications offers new opportunities for realizing integrated optical and wireless network infrastructures. We report on some of our recent activities investigating advanced technologies for next generation converged optical wireless networks. Developments in Active Antenna Systems, mobile fronthaul architectures, and 60 GHz fiber distributed wireless networks are described. We also discuss the potential for analog radio over fiber distribution links as a viable solution for meeting the capacity requirements of new network architectures.

  14. Optical fiber stripper positioning apparatus

    DOEpatents

    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.

  15. Infrared Fiber Optics.

    DTIC Science & Technology

    1979-12-01

    This unit is thca placed in a larger plastic tube which mates with the fiber connectors. Commercial AMP connectors are used that allow the fiber cable...AD-A082 450 HUSHES RESEARCH LABS MALIBU CA pie 20/6 INFRARED FIBER OPTICS.(U) DEC 79 J A HARRINSTON, R TURK, M HENDERSON F1962-R78-C-0109...Laboratories AE.WR r z7 3011 Malibu Canyon Road t 2 Hanscom AFB MA 01731 E I NUBROPAS I5s. OECLASSIFI ATION/DOWNGRADING SN/ A SCHEDULE 16. DISTRI13UTION

  16. Fiber Optic Control System integration for advanced aircraft. Electro-optic and sensor fabrication, integration, and environmental testing for flight control systems

    NASA Technical Reports Server (NTRS)

    Seal, Daniel W.; Weaver, Thomas L.; Kessler, Bradley L.; Bedoya, Carlos A.; Mattes, Robert E.

    1994-01-01

    This report describes the design, development, and testing of passive fiber optic sensors and a multiplexing electro-optic architecture (EOA) for installation and flight test on a NASA-owned F-18 aircraft. This hardware was developed under the Fiber Optic Control Systems for Advanced Aircraft program, part of a multiyear NASA initiative to design, develop, and demonstrate through flight test 'fly-by-light' systems for application to advanced aircraft flight and propulsion control. This development included the design and production of 10 passive optical sensors and associated multiplexed EOA hardware based on wavelength division multiplexed (WDM) technology. A variety of sensor types (rotary position, linear position, temperature, and pressure) incorporating a broad range of sensor technologies (WDM analog, WDM digital, analog microbend, and fluorescent time rate of decay) were obtained from different manufacturers and functionally integrated with an independently designed EOA. The sensors were built for installation in a variety of aircraft locations, placing the sensors in a variety of harsh environments. The sensors and EOA were designed and built to have the resulting devices be as close as practical to a production system. The integrated system was delivered to NASA for flight testing on a NASA-owned F-18 aircraft. Development and integration testing of the system provided valuable information as to which sensor types were simplest to design and build for a military aircraft environment and which types were simplest to operate with a multiplexed EOA. Not all sensor types met the full range of performance and environmental requirements. EOA development problems provided information on directions to pursue in future fly-by-light flight control development programs. Lessons learned in the development of the EOA and sensor hardware are summarized.

  17. Fiber Optic Control System integration for advanced aircraft. Electro-optic and sensor fabrication, integration, and environmental testing for flight control systems

    NASA Astrophysics Data System (ADS)

    Seal, Daniel W.; Weaver, Thomas L.; Kessler, Bradley L.; Bedoya, Carlos A.; Mattes, Robert E.

    1994-11-01

    This report describes the design, development, and testing of passive fiber optic sensors and a multiplexing electro-optic architecture (EOA) for installation and flight test on a NASA-owned F-18 aircraft. This hardware was developed under the Fiber Optic Control Systems for Advanced Aircraft program, part of a multiyear NASA initiative to design, develop, and demonstrate through flight test 'fly-by-light' systems for application to advanced aircraft flight and propulsion control. This development included the design and production of 10 passive optical sensors and associated multiplexed EOA hardware based on wavelength division multiplexed (WDM) technology. A variety of sensor types (rotary position, linear position, temperature, and pressure) incorporating a broad range of sensor technologies (WDM analog, WDM digital, analog microbend, and fluorescent time rate of decay) were obtained from different manufacturers and functionally integrated with an independently designed EOA. The sensors were built for installation in a variety of aircraft locations, placing the sensors in a variety of harsh environments. The sensors and EOA were designed and built to have the resulting devices be as close as practical to a production system. The integrated system was delivered to NASA for flight testing on a NASA-owned F-18 aircraft. Development and integration testing of the system provided valuable information as to which sensor types were simplest to design and build for a military aircraft environment and which types were simplest to operate with a multiplexed EOA. Not all sensor types met the full range of performance and environmental requirements. EOA development problems provided information on directions to pursue in future fly-by-light flight control development programs. Lessons learned in the development of the EOA and sensor hardware are summarized.

  18. Precision Fiber Optic Sensor Market Forecast

    NASA Astrophysics Data System (ADS)

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

    1986-01-01

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

  19. Fiber optic fluid detector

    DOEpatents

    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.

  20. Fiber optic fluid detector

    DOEpatents

    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.

  1. Enhanced radiation resistant fiber optics

    DOEpatents

    Lyons, Peter B.; Looney, Larry D.

    1993-01-01

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

  2. Enhanced radiation resistant fiber optics

    DOEpatents

    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.

  3. Fiber-Optic Sensing Technology

    SciTech Connect

    Milnes, M.; Baylor, L.C.; Bave, S.

    1996-10-24

    This article offers a basic review of fiber-optic sensing technology, or more specifically, fiber-optic sensing technology as applied to the qualitative or quantitative identification of a chemical sample, and how it works,

  4. Optical sensors based on plastic fibers.

    PubMed

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

    2012-01-01

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

  5. Reduced Gravity Zblan Optical Fiber

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  6. Optical Fiber Protection

    NASA Technical Reports Server (NTRS)

    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

  7. Fiber optic temperature sensor

    NASA Technical Reports Server (NTRS)

    Quick, William H. (Inventor); August, Rudolf R. (Inventor); James, Kenneth A. (Inventor); Strahan, Jr., Virgil H. (Inventor); Nichols, Donald K. (Inventor)

    1980-01-01

    An inexpensive, lightweight fiber optic micro-sensor that is suitable for applications which may require remote temperature sensing. The disclosed temperature sensor includes a phosphor material that, after receiving incident light stimulation, is adapted to emit phosphorescent radiation output signals, the amplitude decay rate and wavelength of which are functions of the sensed temperature.

  8. Improved Optical Fiber Chemical Sensors

    NASA Technical Reports Server (NTRS)

    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.

  9. Buying Fiber-Optic Networks.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2003-01-01

    Describes consortia formed by college and university administrators to buy, manage, and maintain their own fiber-optic networks with the goals of cutting costs of leasing fiber-optic cable and planning for the future. Growth capacity is the real advantage of owning fiber-optic systems. (SLD)

  10. Large core fiber optic cleaver

    DOEpatents

    Halpin, John M.

    1996-01-01

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

  11. Fiber Optics and Library Technology.

    ERIC Educational Resources Information Center

    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)

  12. Large core fiber optic cleaver

    DOEpatents

    Halpin, J.M.

    1996-03-26

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

  13. Aerogel-clad optical fiber

    DOEpatents

    Sprehn, Gregory A.; Hrubesh, Lawrence W.; Poco, John F.; Sandler, Pamela H.

    1997-01-01

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

  14. Aerogel-clad optical fiber

    DOEpatents

    Sprehn, G.A.; Hrubesh, L.W.; Poco, J.F.; Sandler, P.H.

    1997-11-04

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency. 4 figs.

  15. Fiber optic communication in borehole applications

    SciTech Connect

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

    1997-04-01

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

  16. Calibration of Fast Fiber-Optic Beam Loss Monitors for the Advanced Photon Source Storage Ring Superconducting Undulators

    SciTech Connect

    Dooling, J.; Harkay, K.; Ivanyushenkov, Y.; Sajaev, V.; Xiao, A.; Vella, Andrea K.

    2015-01-01

    We report on the calibration and use of fast fiber-optic (FO) beam loss monitors (BLMs) in the Advanced Photon Source storage ring (SR). A superconducting undulator prototype (SCU0) has been operating in SR Sector 6 (“ID6”) since the beginning of CY2013, and another undulator SCU1 (a 1.1-m length undulator that is three times the length of SCU0) is scheduled for installation in Sector 1 (“ID1”) in 2015. The SCU0 main coil often quenches during beam dumps. MARS simulations have shown that relatively small beam loss (<1 nC) can lead to temperature excursions sufficient to cause quenchingwhen the SCU0windings are near critical current. To characterize local beam losses, high-purity fused-silica FO cables were installed in ID6 on the SCU0 chamber transitions and in ID1 where SCU1 will be installed. These BLMs aid in the search for operating modes that protect the SCU structures from beam-loss-induced quenching. In this paper, we describe the BLM calibration process that included deliberate beam dumps at locations of BLMs. We also compare beam dump events where SCU0 did and did not quench.

  17. Optical Fiber Spectroscopy

    NASA Technical Reports Server (NTRS)

    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.

  18. Optical fiber synaptic sensor

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  19. Fiber Optic Velocity Interferometry

    SciTech Connect

    Neyer, Barry T.

    1988-04-01

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

  20. Optical fiber laser

    SciTech Connect

    Hakimi, F.; Po, H.; Snitzer, E.

    1987-07-14

    An optical fiber laser is described comprising: a gain cavity including a single mode optical fiber of given length having a core with a given index of refraction and a cladding surrounding the core and having an index of refraction lower than that of the core. The core comprises a host glass having incorporated a laser gain material with a fluorescence spectrum having at least one broadband region in which there is at least one peak emission line; filter means optically coupled to one end of the gain cavity and reflective to radiation emitted from the gain material over a predetermined wavelength interval about the peak emission line to provide feedback in the gain cavity; an etalon filter section butt coupled to the remaining end of the gain cavity optical fiber, the etalon filter section comprising a pair of filters spaced apart in parallel by a predetermined length of material transparent to any radiation emitted from the gain cavity. The predetermined length of the transparent material is such that the etalon filter section is no longer than the distance over which the wave train energy from the fiber core remains substantially planar so that the etalon filter section is inside the divergent region to enhance feedback in the gain cavity; and means for pumping energy into the gain cavity to raise the interval energy level such that only a small part of the ion population, corresponding to a predetermined bandwidth about the peak emission line, is raised above laser threshold. The laser emits radiation only over narrow lines over a narrow wavelength interval centered about the peak emission line.

  1. Fiber optic geophysical sensors

    DOEpatents

    Homuth, Emil F.

    1991-01-01

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

  2. Shedding Light on Fiber Optics.

    ERIC Educational Resources Information Center

    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)

  3. Honeywell FLASH fiber optic motherboard evaluations

    NASA Astrophysics Data System (ADS)

    Stange, Kent

    1996-10-01

    The use of fiber optic data transmission media can make significant contributions in achieving increasing performance and reduced life cycle cost requirements placed on commercial and military transport aircraft. For complete end-to-end fiber optic transmission, photonics technologies and techniques need to be understood and applied internally to the aircraft line replaceable units as well as externally on the interconnecting aircraft cable plant. During a portion of the Honeywell contribution to Task 2A on the Fly- by-Light Advanced System Hardware program, evaluations were done on a fiber optic transmission media implementation internal to a Primary Flight Control Computer (PFCC). The PFCC internal fiber optic transmission media implementation included a fiber optic backplane, an optical card-edge connector, and an optical source/detector coupler/installation. The performance of these optical media components were evaluated over typical aircraft environmental stresses of temperature, vibration, and humidity. These optical media components represent key technologies to the computer end-to-end fiber optic transmission capability on commercial and military transport aircraft. The evaluations and technical readiness assessments of these technologies will enable better perspectives on productization of fly-by-light systems requiring their utilizations.

  4. Spectrally Analyzed Embedded Infrared Fiber Optic Diagnostic of Advanced Composite Propellant Combustion

    DTIC Science & Technology

    2006-05-31

    observations, XM39. This nitramine composite propellant is 76 per cent RDX with most of the balance made up by the binder cellulose acetate butyrate and the...13 Figure 7 Predicted Model Spectrum for Pure Decomposition Gas at 6 atm with a 0.3 cm Absorption Path Length...program of in situ diagnostics and laboratory experiments has led to more advanced models of the gas phase processes in the dark zone and secondary flame

  5. Fiber optic systems for mobile platforms II

    SciTech Connect

    Lewis, N.E.; Moore, E.L.

    1988-01-01

    This book contains papers presented at the symposium of International Society for Optical Engineering. Topics covered/include: Fiber optic pressure sensor for internal combustion engine; Automotive fiber optic technology: application issues; and Fiber optic guided missile.

  6. Interferometric Fiber Optic Sensors

    PubMed Central

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

    2012-01-01

    Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG) is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair. PMID:22736961

  7. Interferometric fiber optic sensors.

    PubMed

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

    2012-01-01

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

  8. Selenium semiconductor core optical fibers

    SciTech Connect

    Tang, G. W.; Qian, Q. Peng, K. L.; Wen, X.; Zhou, G. X.; Sun, M.; Chen, X. D.; Yang, Z. M.

    2015-02-15

    Phosphate glass-clad optical fibers containing selenium (Se) semiconductor core were fabricated using a molten core method. The cores were found to be amorphous as evidenced by X-ray diffraction and corroborated by Micro-Raman spectrum. Elemental analysis across the core/clad interface suggests that there is some diffusion of about 3 wt % oxygen in the core region. Phosphate glass-clad crystalline selenium core optical fibers were obtained by a postdrawing annealing process. A two-cm-long crystalline selenium semiconductor core optical fibers, electrically contacted to external circuitry through the fiber end facets, exhibit a three times change in conductivity between dark and illuminated states. Such crystalline selenium semiconductor core optical fibers have promising utility in optical switch and photoconductivity of optical fiber array.

  9. Fiber optic TV direct

    NASA Technical Reports Server (NTRS)

    Kassak, John E.

    1991-01-01

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

  10. System for testing optical fibers

    DOEpatents

    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.

  11. System for testing optical fibers

    DOEpatents

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

    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. 2 figs.

  12. Fiber optic geophysical sensors

    DOEpatents

    Homuth, E.F.

    1991-03-19

    A fiber optic geophysical sensor is described in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects. 2 figures.

  13. Optical fiber networks for remote fiber optic sensors.

    PubMed

    Fernandez-Vallejo, Montserrat; Lopez-Amo, Manuel

    2012-01-01

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

  14. Optical Fiber Networks for Remote Fiber Optic Sensors

    PubMed Central

    Fernandez-Vallejo, Montserrat; Lopez-Amo, Manuel

    2012-01-01

    This paper presents an overview of optical fiber sensor networks for remote sensing. Firstly, the state of the art of remote fiber sensor systems has been considered. We have summarized the great evolution of these systems in recent years; this progress confirms that fiber-optic remote sensing is a promising technology with a wide field of practical applications. Afterwards, the most representative remote fiber-optic sensor systems are briefly explained, discussing their schemes, challenges, pros and cons. Finally, a synopsis of the main factors to take into consideration in the design of a remote sensor system is gathered. PMID:22666011

  15. Fiber optic to integrated optical chip coupler

    NASA Technical Reports Server (NTRS)

    Pikulski, Joseph I. (Inventor); Ramer, O. Glenn (Inventor)

    1987-01-01

    Optical fibers are clamped by a block onto a substrate. Thereupon, metal is plated over the fibers to hold them in place upon the substrate. The clamp block is removed and the opening, resulting from the clamp block's presence, is then plated in. The built-up metallic body is a coupling which holds the fibers in position so that the ends can be polished for coupling to an integrated optical chip upon a coupling fixture.

  16. Optical Fibers for Nonlinear Optics.

    DTIC Science & Technology

    1986-10-01

    wavelength, showing structure due to water absorption bands .............................. 21 11 Schematic diagram of the experimental apparatus for phase...Figure 10. (b) Spectrum of PK3 fiber attenuation versus wavelength, showing structure due to water absorption bands. -L -L1 D C- LCL 0 (0 o o wj 0 00zzo...crystal fibers (ADP). 1984 Development of traveling zone method converting polycrystalline extruded fiber to single-crystal fiber (AgCl, AgBr, CuCl

  17. Fabrication of Optical Fiber Devices

    NASA Astrophysics Data System (ADS)

    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.

  18. Optical-Fiber Leak Detector

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Kosten, Susan E.

    1994-01-01

    Proposed optical-fiber sensor detects small changes in pressure in elastomeric O-ring or similar pressure seal, which may indicate deterioration of seal and interpreted as indications of incipient failure. According to concept, length of optical fiber embedded in seal. Light-emitting diode illuminates one end of fiber; photodetector measures intensity of light emerging from other end. Pressure-induced changes in seal bend fiber slightly, altering microbending-induced loss of light from fiber and alter intensity of light at photodetector. Change in intensity approximately proportional to change in pressure.

  19. Experimental optical fiber communications link

    NASA Technical Reports Server (NTRS)

    Lutes, G. F.

    1980-01-01

    An optical fiber communications link 1.5 kilometers in length was installed between the Interim Frequency Standard Test Facility and the Timing and Frequency Systems Research Laboratory at JPL. It is being used to develop optical fiber technology for use in the DSN and particularly for precise time and frequency distribution.

  20. Fiber optic and laser sensors VIII; Proceedings of the Meeting, San Jose, CA, Sept. 17-19, 1990

    NASA Technical Reports Server (NTRS)

    Depaula, Ramon P. (Editor); Udd, Eric (Editor)

    1991-01-01

    This issue presents topics on the advances in fiber-optic sensor technology, fiber-optic gyroscope, fiber-optic position and pressure sensors, fiber-optic magnetic and temperature sensors, and generic fiber-optic sensors. Papers included are on a novel analog phase tracker for interferometric fiber-optic sensor applications, recent development status of fiber-optic sensors in China, the magnetic-field sensitivity of depolarized fiber-optic gyros, a depolarized fiber-optic gyro for future tactical applications, fiber-optic position transducers for aircraft controls, and a metal embedded optical-fiber pressure sensor. Attention is also given to a fiber-optic magnetic field sensor using spectral modulation encoding, a bare-fiber temperature sensor, an interferometric fiber-optic accelerometer, improvement of specular reflection pyrometer, a theoretical analysis of two-mode elliptical-core optical fiber sensors, and a fiber probe for ring pattern.

  1. Fiber optic sensor and method for making

    DOEpatents

    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.

  2. Fiber-optic technology review

    SciTech Connect

    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 ..mu..m and development of wavelengths multiplexers for simultaneous system operation at several wavelengths.

  3. Optical fiber inspection system

    DOEpatents

    Moore, F.W.

    1985-04-05

    A remote optical inspection system including an inspection head. The inspection head has a passageway through which pellets or other objects are passed. A window is provided along the passageway through which light is beamed against the objects being inspected. A plurality of lens assemblies are arranged about the window so that reflected light can be gathered and transferred to a plurality of coherent optical fiber light guides. The light guides transfer the light images to a television or other image transducer which converts the optical images into a representative electronic signal. The electronic signal can then be displayed on a signal viewer such as a television monitor for inspection by a person. A staging means can be used to support the objects for viewing through the window. Routing means can be used to direct inspected objects into appropriate exit passages for accepted or rejected objects. The inspected objects are advantageously fed in a singular manner to the staging means and routing means. The inspection system is advantageously used in an enclosure when toxic or hazardous materials are being inspected. 10 figs.

  4. Optical fiber inspection system

    DOEpatents

    Moore, Francis W.

    1987-01-01

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

  5. Recycling optical fibers for sensing

    NASA Astrophysics Data System (ADS)

    André, Paulo; Domingues, Fátima; Alberto, Nélia; Marques, Carlos; Antunes, Paulo

    2016-04-01

    Optical fiber sensors has become one of the most promising sensing technologies. Within all the optical fiber sensing technologies, the Fabry-Perot interferometer (FPI) micro-cavities are one of the most attractive, due to the size, linearity and higher sensitivity. In this work we present the recent results, achieved by our group, regarding the production of optical sensors, by recycling optical fibers destroyed through the catastrophic fuse effect. This enabled the production of FPI sensors, in a cost effective way, tailored for the monitoring of several physical parameters, such as relative humidity (RH), refractive index (RI) and hydrostatic pressure.

  6. Advanced fiber lasers and related all-fiber devices

    NASA Astrophysics Data System (ADS)

    Srinivasan, Balaji

    2000-11-01

    :ZBLAN. The demonstration of substantial second order nonlinearities (~1 pm/V) at UNM using thermal- assisted poling in normally symmetry forbidden silica glass has inspired worldwide research efforts aimed at achieving similar nonlinearities in fibers. All-fiber electro-optic devices based on such poled fibers are anticipated to enhance the performance of various lasers, including modelocked and tunable fiber lasers. This dissertation presents the first demonstration of stable, electro-optically tunable fiber Bragg gratings (FBGs) with a tuning range of 20 pm (2.5 GHz), which should enable applications such as reconfigurable add/drop filters and actively modelocked all-fiber lasers. Two key steps in the fabrication of the tunable FBGs viz. the fabrication of thermally stable FBGs, and a novel method for in-situ monitoring of fiber polishing are also demonstrated. Finally, this dissertation discusses issues related to the demonstration of all-fiber electro- optically tunable polarization rotators and their possible impact on future advanced fiber lasers.

  7. Optical Sensors Based on Plastic Fibers

    PubMed Central

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

    2012-01-01

    The recent advances of polymer technology allowed the introduction of plastic optical fiber in sensor design. The advantages of optical metrology with plastic optical fiber have attracted the attention of the scientific community, as they allow the development of low-cost or cost competitive systems compared with conventional technologies. In this paper, the current state of the art of plastic optical fiber technology will be reviewed, namely its main characteristics and sensing advantages. Several measurement techniques will be described, with a strong focus on interrogation approaches based on intensity variation in transmission and reflection. The potential applications involving structural health monitoring, medicine, environment and the biological and chemical area are also presented. PMID:23112707

  8. Fiber optic gyros from research to production

    NASA Astrophysics Data System (ADS)

    Pavlath, George A.

    2016-05-01

    Fiber optic gyros are a great success story for a new inertial measurement technology that successfully transitioned from the laboratory in 1975 to production in 1992. This paper will review their research, advanced development, product development, and production transfer. The focus of the paper will be this cycle from Stanford University to Northrop Grumman.

  9. Fiber optic interferometric sensors for aerospace applications

    NASA Technical Reports Server (NTRS)

    Cho, Y. C.

    1994-01-01

    This paper addresses two fiber optic sensor development programs in the Photonics Laboratory, NASA Ames Research Center, one in progress and the other being initiated. The ongoing program involves development of advanced acoustic sensors for wind tunnel applications. The new undertaking involves development of a novel sensor technique for studies of aerodynamic transition from laminar to turbulent flow.

  10. Fiber optic-based biosensor

    NASA Technical Reports Server (NTRS)

    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.

  11. Optical fiber dispersion characterization study

    NASA Technical Reports Server (NTRS)

    Geeslin, A.; Arriad, A.; Riad, S. M.; Padgett, M. E.

    1979-01-01

    The theory, design, and results of optical fiber pulse dispersion measurements are considered. Both the hardware and software required to perform this type of measurement are described. Hardware includes a thermoelectrically cooled injection laser diode source, an 800 GHz gain bandwidth produce avalanche photodiode and an input mode scrambler. Software for a HP 9825 computer includes fast Fourier transform, inverse Fourier transform, and optimal compensation deconvolution. Test set construction details are also included. Test results include data collected on a 1 Km fiber, a 4 Km fiber, a fused spliced, eight 600 meter length fibers concatenated to form 4.8 Km, and up to nine optical connectors.

  12. Optical Fiber Sensing Using Quantum Dots

    PubMed Central

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

    2007-01-01

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

  13. Fiber optic multiplex optical transmission system

    NASA Technical Reports Server (NTRS)

    Bell, C. H. (Inventor)

    1977-01-01

    A multiplex optical transmission system which minimizes external interference while simultaneously receiving and transmitting video, digital data, and audio signals is described. Signals are received into subgroup mixers for blocking into respective frequency ranges. The outputs of these mixers are in turn fed to a master mixer which produces a composite electrical signal. An optical transmitter connected to the master mixer converts the composite signal into an optical signal and transmits it over a fiber optic cable to an optical receiver which receives the signal and converts it back to a composite electrical signal. A de-multiplexer is coupled to the output of the receiver for separating the composite signal back into composite video, digital data, and audio signals. A programmable optic patch board is interposed in the fiber optic cables for selectively connecting the optical signals to various receivers and transmitters.

  14. An inexpensive high-temperature optical fiber thermometer

    NASA Astrophysics Data System (ADS)

    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.

  15. High-sensitivity fiber optic acoustic sensors

    NASA Astrophysics Data System (ADS)

    Lu, Ping; Liu, Deming; Liao, Hao

    2016-11-01

    Due to the overwhelming advantages compared with traditional electronicsensors, fiber-optic acoustic sensors have arisen enormous interest in multiple disciplines. In this paper we present the recent research achievements of our group on fiber-optic acoustic sensors. The main point of our research is high sensitivity interferometric acoustic sensors, including Michelson, Sagnac, and Fabry-Pérot interferometers. In addition, some advanced technologies have been proposed for acoustic or acoustic pressure sensing such as single-mode/multimode fiber coupler, dual FBGs and multi-longitudinal mode fiber laser based acoustic sensors. Moreover, our attention we have also been paid on signal demodulation schemes. The intensity-based quadrature point (Q-point) demodulation, two-wavelength quadrature demodulation and symmetric 3×3 coupler methodare discussed and compared in this paper.

  16. Fiber optics that fly

    NASA Astrophysics Data System (ADS)

    Wilcox, Michael J.; Thelen, Donald C., Jr.

    1996-11-01

    analog integrated circuit using photodiodes and fiber optic waveguides as the nonlinear light sensing devices, current mirrors and opamp circuits for the processing. The outputs of this circuit will go to other artificial neural networks for further processing.

  17. Scintillator fiber optic long counter

    DOEpatents

    McCollum, T.; Spector, G.B.

    1994-03-29

    A flat response position sensitive neutron detector capable of providing neutron spectroscopic data utilizing scintillator fiber optic filaments embedded in a neutron moderating housing having an open end through which neutrons enter to be detected is described. 11 figures.

  18. Fiber Optics: A Bright Future.

    ERIC Educational Resources Information Center

    Rice, James, Jr.

    1980-01-01

    Presents an overview of the impact of fiber optics on telecommunications and its application to information processing and library services, including information retrieval, news services, remote transmission of library services, and library networking. (RAA)

  19. Connector For Embedded Optical Fiber

    NASA Technical Reports Server (NTRS)

    Wilkerson, Charles; Hiles, Steven; Houghton, J. Richard; Holland, Brent W.

    1994-01-01

    Partly embedded fixture is simpler and sturdier than other types of outlets for optical fibers embedded in solid structures. No need to align coupling prism and lenses. Fixture includes base, tube bent at 45 degree angle, and ceramic ferrule.

  20. Scintillator fiber optic long counter

    DOEpatents

    McCollum, Tom; Spector, Garry B.

    1994-01-01

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

  1. System for testing optical fibers

    DOEpatents

    Davies, Terence J.; Franks, Larry A.; Nelson, Melvin A.

    1981-01-01

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

  2. Fiber optic refractive index monitor

    SciTech Connect

    Weiss, Jonathan David

    2002-01-01

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

  3. Fiber optic diffraction grating maker

    DOEpatents

    Deason, V.A.; Ward, M.B.

    1991-05-21

    A compact and portable diffraction grating maker is comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate. 4 figures.

  4. Fiber optic diffraction grating maker

    DOEpatents

    Deason, Vance A.; Ward, Michael B.

    1991-01-01

    A compact and portable diffraction grating maker comprised of a laser beam, optical and fiber optics devices coupling the beam to one or more evanescent beam splitters, and collimating lenses or mirrors directing the split beam at an appropriate photosensitive material. The collimating optics, the output ends of the fiber optic coupler and the photosensitive plate holder are all mounted on an articulated framework so that the angle of intersection of the beams can be altered at will without disturbing the spatial filter, collimation or beam quality, and assuring that the beams will always intersect at the position of the plate.

  5. Light diffusing fiber optic chamber

    DOEpatents

    Maitland, Duncan J.

    2002-01-01

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

  6. Fiber-optic voltage sensor

    NASA Astrophysics Data System (ADS)

    Wood, C. B.

    1990-07-01

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

  7. Embedded fiber-optic sensing for accurate internal monitoring of cell state in advanced battery management systems part 1: Cell embedding method and performance

    NASA Astrophysics Data System (ADS)

    Raghavan, Ajay; Kiesel, Peter; Sommer, Lars Wilko; Schwartz, Julian; Lochbaum, Alexander; Hegyi, Alex; Schuh, Andreas; Arakaki, Kyle; Saha, Bhaskar; Ganguli, Anurag; Kim, Kyung Ho; Kim, ChaeAh; Hah, Hoe Jin; Kim, SeokKoo; Hwang, Gyu-Ok; Chung, Geun-Chang; Choi, Bokkyu; Alamgir, Mohamed

    2017-02-01

    A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic sensors. High-performance large-format pouch cells with embedded fiber-optic sensors were fabricated. The first of this two-part paper focuses on the embedding method details and performance of these cells. The seal integrity, capacity retention, cycle life, compatibility with existing module designs, and mass-volume cost estimates indicate their suitability for xEV and other advanced battery applications. The second part of the paper focuses on the internal strain and temperature signals obtained from these sensors under various conditions and their utility for high-accuracy cell state estimation algorithms.

  8. Fiber optic frequency transfer link

    NASA Technical Reports Server (NTRS)

    Primas, Lori E. (Inventor); Sydnor, Richard L. (Inventor); Lutes, George F. (Inventor)

    1991-01-01

    A reference frequency distribution system is disclosed for transmitting a reference frequency from a reference unit to a remote unit while keeping the reference frequency at the reference unit and the remote unit in phase. A fiber optic cable connects the reference unit to the remote unit. A frequency source at the reference unit produces a reference frequency having an adjustable phase. A fiber optic transmitter at the reference unit modulates a light beam with the reference frequency and transmits the light beam into the fiber optic cable. A 50/50 reflector at the remote unit reflects a first portion of the light beam from the reference unit back into the fiber optic cable to the reference unit. A first fiber optic receiver disposed at the remote unit receives a second portion of the light beam and demodulates the reference frequency to be used at the remote unit. A second fiber optic receiver disposed at the reference unit receives the first portion of the light beam and demodulates a reference frequency component. A phase conjugator is connected to the frequency source for comparing the phase of the reference frequency component to the phase of the reference frequency modulating the light beam being transmitted from the reference unit to maintain a conjugate (anti-symmetric) relationship between the reference frequency component and the reference frequency modulating the light beam where virtually no phase difference exists between the phase of the reference frequency component and the phase of the reference frequency modulating the light beam.

  9. Fiber Ring Optical Gyroscope (FROG)

    NASA Technical Reports Server (NTRS)

    1979-01-01

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

  10. Fiber optic Adaline neural networks

    NASA Astrophysics Data System (ADS)

    Ghosh, Anjan K.; Trepka, Jim; Paparao, Palacharla

    1993-02-01

    Optoelectronic realization of adaptive filters and equalizers using fiber optic tapped delay lines and spatial light modulators has been discussed recently. We describe the design of a single layer fiber optic Adaline neural network which can be used as a bit pattern classifier. In our realization we employ as few electronic devices as possible and use optical computation to utilize the advantages of optics in processing speed, parallelism, and interconnection. The new optical neural network described in this paper is designed for optical processing of guided lightwave signals, not electronic signals. We analyzed the convergence or learning characteristics of the optically implemented Adaline in the presence of errors in the hardware, and we studied methods for improving the convergence rate of the Adaline.

  11. Supercontinuum Generation in Optical Fibers

    NASA Astrophysics Data System (ADS)

    Dudley, J. M.; Taylor, J. R.

    2010-04-01

    1. Introduction and history J. R. Taylor; 2. Supercontinuum generation in microstructure fiber - an historical note J. K. Ranka; 3. Nonlinear fiber optics overview J. C. Travers, M. H. Frosz and J. M. Dudley; 4. Fiber supercontinuum generation overview J. M. Dudley; 5. Silica fibers for supercontinuum generation J. C. Knight and W. Wadsworth; 6. Supercontinuum generation and nonlinearity in soft glass fibers J. H. V. Price and D. J. Richardson; 7. Increasing the blue-shift of a picosecond pumped supercontinuum M. H. Frosz, P. M. Moselund, P. D. Rasmussen, C. L. Thomsen and O. Bang; 8. Continuous wave supercontinuum generation J. C. Travers; 9. Theory of supercontinuum and interactions of solitons with dispersive waves D. V. Skryabin and A. V. Gorbach; 10. Interaction of four-wave mixing and stimulated Raman scattering in optical fibers S. Coen, S. G. Murdoch and F. Vanholsbeeck; 11. Nonlinear optics in emerging waveguides: revised fundamentals and implications S. V. Afshar, M. Turner and T. M. Monro; 12. Supercontinuum generation in dispersion varying fibers G. Genty; 13. Supercontinuum generation in chalcogenide glass waveguides Dong-Il Yeom, M. R. E. Lamont, B. Luther Davies and B. J. Eggleton; 14. Supercontinuum generation for carrier-envelope phase stabilization of mode-locked lasers S. T. Cundiff; 15. Biophotonics applications of supercontinuum generation C. Dunsby and P. M. W. French; 16. Fiber sources of tailored supercontinuum in nonlinear microspectroscopy and imaging A. M. Zheltikov; Index.

  12. Optical fiber instrumentation and applications

    NASA Astrophysics Data System (ADS)

    Claus, Richard O.

    1997-11-01

    Optical fiber-based sensor instrumentation has been used extensively for the measurement of physical observables including strain, temperature and chemical changes in smart materials and smart structures, and have been integrated with MEMS devices to provide multi-measurement capability along the length of a fiber link or network. This plenary paper briefly outlines recent developments in such optical fiber sensor instrumentation. Fiber optic sensors are small in size, immune to electromagnetic interference and can be easily integrated with existing optical fiber hardware and components that have been developed primarily for use in the larger telecommunications market. Such sensors can be easily multiplexed, resulting in networks that can be used for the health monitoring of large structures, or the real-time monitoring of structural parameters required for structural analysis and control. This paper briefly describes and compares three current fiber sensor configurations that use Fabry-Perot interferometry and fiber Bragg gratings (FBG) and long-period grating (LPG) elements to monitor strain, temperature and other parameters. Extensive details concerning additional related work and field test results and applications are discussed in the references.

  13. Optical fiber instrumentation and applications

    NASA Astrophysics Data System (ADS)

    Claus, Richard O.

    1997-11-01

    Optical fiber-based sensor instrumentation has been used extensively for the measurement of physical observables including strain, temperature and chemical changes in smart materials and smart structures, and have been integrated with MEMS devices to provide multi-measurement capability along the length of a fiber link or network. This plenary paper briefly outlines recent developments in such optical fiber sensor instrumentation. Fiber optic sensors are small in size, immune to electromagnetic interference and can be easily integrated with existing optical fiber hardware nd components that have been developed primarily for use in the larger telecommunications market. Such sensors can be easily multiplexed, resulting in networks that can be used for the health monitoring of large structures, or the real-time monitoring of structural parameters required for structural analysis and control. This paper briefly describes and compares three current fiber sensor configurations that use Fabry-Perot interferometry and fiber Bragg gratings and long-period grating elements to monitor strain, temperature and other parameters. Extensive details concerning additional related work and field test results and applications are discussed in the references.

  14. Monolithic fiber optic sensor assembly

    SciTech Connect

    Sanders, Scott

    2015-02-10

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

  15. Oceanic Applications of Fiber Optics

    DTIC Science & Technology

    1991-12-01

    Overview", Procof.IE, Vol. 566, Fiber Engine.ing, Vol. 5. pp. 97-103, July 1986. Optic and Laser Sensors I1, [566-01], 1985. [3) S. Shibata , M . Horiguchi...and Laser Sensors UII, [566-011, 1985. [3] S. Shibata , M . Horiguchi, S. Mitachi, and T. [161 N. Lagakos, "Multimode optical fiber displacement Manabe...Engineering, Vol. 5, pp. 97-103, July 1986. Optic and Laser Sensors HII, [566-01], 1985. [31 S. Shibata , M . Horiguchi, S. Mitachi, and T. [16] N

  16. Fiber optic crossbar switch for automatically patching optical signals

    NASA Technical Reports Server (NTRS)

    Bell, C. H. (Inventor)

    1983-01-01

    A system for automatically optically switching fiber optic data signals between a plurality of input optical fibers and selective ones of a plurality of output fibers is described. The system includes optical detectors which are connected to each of the input fibers for converting the optic data signals appearing at the respective input fibers to an RF signal. A plurality of RF to optical signal converters are arranged in rows and columns. The output of each of the optical detectors are each applied to a respective row of optical signal converted for being converters back to an optical signal when the particular optical signal converter is selectively activated by a dc voltage.

  17. Photochromic glass optical fiber

    NASA Astrophysics Data System (ADS)

    Alvi, Bilal A.; Israr, Amber; Asif, Muhammad; Aamir, Muhammad; Rehan, Muhammad

    2016-02-01

    This paper describes the fabrication and analysis of novel twin cored fiber which contains a transparent and silver halide doped photochromic core in same cladding. The Photochromic core fibers were fabricated in twin cored structure by rode and tube method. The diameter of photochromic core and transparent core is around 15 m. The distance between two cores is 1.5m. The transparent core was used to guide the probe beam and photochromic core was excited by UV source. The interaction of the probe beam with the excited photochromic core showed the photochromic behavior of the fiber.

  18. In situ composite cure monitoring using infrared transmitting optical fibers

    NASA Technical Reports Server (NTRS)

    Young, Philip R.; Druy, Mark A.; Stevenson, W. A.; Compton, David A. C.

    1988-01-01

    The development of infrared-transmitting optical fibers as sensors for monitoring the cure of advanced composite materials is reported. Fourier transform infrared spectra are presented which were remotely sensed during the cure of a high performance polyimide resin and a graphite/polyimide matrix prepreg using an 0.1 mm O.D. x 3 m chalcogenide optical fiber. A discussion of the fiber and sensor element, absorption mechanism and potential applications is presented.

  19. Mode coupling in multimode plastic optical fiber

    NASA Astrophysics Data System (ADS)

    Wang, Jing

    1999-10-01

    . Material dispersion, in addition to waveguide dispersion, are found to have a huge impact on the optical transmission behavior of a fiber waveguide. The theoretical bandwidth values for the SI and GI POF samples are calculated from the measured index profiles and the corresponding DMA results and determined to be 27 MHz per 100m for SI and 0.43 GHz per 100m for GI. Work is underway to further study the origin and nature of index perturbations with advanced microscopy and light scattering measurements. The confocal microscopic images obtained recently have already revealed the trace of density fluctuations in SI POF. (Abstract shortened by UMI.)

  20. Fiber optic gas sensor

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  1. Optical fiber feedback SQUID magnetometer

    SciTech Connect

    Naito, S.; Sampei, Y.; Takahashi, T. )

    1989-04-01

    This paper describes an optical fiber feedback superconducting quantum interference device (SQUID) magnetometer which was developed to improve electromagnetic interference characteristics. The SQUID consists of an RF SQUID probe, an RF amplifier, two multimode fibers, and a SQUID control unit. Phase-locked pulse width modulation (PWM) was used to construct a flux locked loop (FLL) circuit in the SQUID control unit. The operation of the optical fiber feedback SQUID is stable when a common mode voltage of ac 100 V/50 Hz is applied. It has an energy resolution of 1 x 10/sup -28/ J/Hz. This paper also describes the measurement of an auditory evoked field from the human brain in a magnetically shielded room using the fiber feedback SQUID with a gradiometer type pickup coil.

  2. Evaluation of two fiber optic-based solar collection and distribution systems for advanced space life support

    NASA Technical Reports Server (NTRS)

    Jack, D. A.; Nakamura, T.; Sadler, P.; Cuello, J. L.

    2002-01-01

    Growing plants in an enclosed controlled environment is crucial in developing bioregenerative life-support systems (BLSS) for space applications. The major challenge currently facing a BLSS is the extensive use of highly energy-intensive electric light sources, which leads to substantial energy wastes through heat dissipations by these lamps. An alternative lighting strategy is the use of a solar irradiance collection, transmission, and distribution system (SICTDS). Two types of fiber optic-based SICTDS, a Fresnel-lens Himawari and a parabolic-mirror optical waveguide (OW) lighting system, were evaluated. The overall efficiency for the OW SICTDS of 40.5% exceeded by 75% that for the Himawari of 23.2%. The spectral distributions of the light delivered by the Himawari and the OW SICTDS were almost identical and had practically no difference from that of terrestrial solar radiation. The ratios of photosynthetically active radiation (PAR) to total emitted radiation (k) of 0.39 +/- 0.02 for the Himawari and 0.41 +/- 0.04 for the OW SICTDS were statistically indistinguishable, were not significantly different from that of 0.042 +/- 0.01 for terrestrial solar radiation, and were comparable to that of 0.35 for a high-pressure sodium (HPS) lamp. The coefficients of variation (CV) of 0.34 and 0.39 for PPF distributions, both at 50 mm X 50 mm square grid arrays, corresponding to the Himawari and the OW SICTDS, respectively, were comparable with each other but were both significantly greater than the CV of 0.08 corresponding to the HPS lamp. The average fresh weight or dry weight of lettuce grown in the solar chamber with either the Himawari or the OW SICTDS showed no statistical difference from the average fresh weight or dry weight of lettuce grown in the reference chamber with the HPS lamp. The results of this study suggest that an SICTDS could help reduce the electric power demand in a BLSS.

  3. Evaluation of two fiber optic-based solar collection and distribution systems for advanced space life support.

    PubMed

    Jack, D A; Nakamura, T; Sadler, P; Cuello, J L

    2002-01-01

    Growing plants in an enclosed controlled environment is crucial in developing bioregenerative life-support systems (BLSS) for space applications. The major challenge currently facing a BLSS is the extensive use of highly energy-intensive electric light sources, which leads to substantial energy wastes through heat dissipations by these lamps. An alternative lighting strategy is the use of a solar irradiance collection, transmission, and distribution system (SICTDS). Two types of fiber optic-based SICTDS, a Fresnel-lens Himawari and a parabolic-mirror optical waveguide (OW) lighting system, were evaluated. The overall efficiency for the OW SICTDS of 40.5% exceeded by 75% that for the Himawari of 23.2%. The spectral distributions of the light delivered by the Himawari and the OW SICTDS were almost identical and had practically no difference from that of terrestrial solar radiation. The ratios of photosynthetically active radiation (PAR) to total emitted radiation (k) of 0.39 +/- 0.02 for the Himawari and 0.41 +/- 0.04 for the OW SICTDS were statistically indistinguishable, were not significantly different from that of 0.042 +/- 0.01 for terrestrial solar radiation, and were comparable to that of 0.35 for a high-pressure sodium (HPS) lamp. The coefficients of variation (CV) of 0.34 and 0.39 for PPF distributions, both at 50 mm X 50 mm square grid arrays, corresponding to the Himawari and the OW SICTDS, respectively, were comparable with each other but were both significantly greater than the CV of 0.08 corresponding to the HPS lamp. The average fresh weight or dry weight of lettuce grown in the solar chamber with either the Himawari or the OW SICTDS showed no statistical difference from the average fresh weight or dry weight of lettuce grown in the reference chamber with the HPS lamp. The results of this study suggest that an SICTDS could help reduce the electric power demand in a BLSS.

  4. Fiber-Optic Temperature Sensor

    NASA Technical Reports Server (NTRS)

    Maram, Jonathan M.

    1987-01-01

    Proposed sensor measures temperatures over wide range, from cryogenic liquids to burning gases. Made in part of optical fibers, sensor lighter in weight than thermocouple and immune to electromagnetic interference. Device does not respond to temperatures elsewhere than at sensing tip. Thermal expansion and contraction of distance between fiber end and mirror alters interference between light reflected from those two surfaces, thereby giving interferometric indication of temperatures.

  5. Spectrally efficient polymer optical fiber transmission

    NASA Astrophysics Data System (ADS)

    Randel, Sebastian; Bunge, Christian-Alexander

    2011-01-01

    The step-index polymer optical fiber (SI-POF) is an attractive transmission medium for high speed communication links in automotive infotainment networks, in industrial automation, and in home networks. Growing demands for quality of service, e.g., for IPTV distribution in homes and for Ethernet based industrial control networks will necessitate Gigabit speeds in the near future. We present an overview on recent advances in the design of spectrally efficient and robust Gigabit-over-SI-POF transmission systems.

  6. Campus fiber optic enterprise networks

    NASA Astrophysics Data System (ADS)

    Weeks, Richard A.

    1991-02-01

    The proliferation of departmental LANs in campus environments has driven network technology to the point where construction of token ring fiber-optic backbone systems is now a cost-effective alternative. This article will discuss several successful real life case history applications of token ring fiber in a campus setting each with unique distance and load factor requirements. It is hoped that these examples will aid in the understanding planning and implementation of similar installations. It will also attempt to provide important information on the emerging Fiber Distributed Data Interface (FDDI) standard.

  7. Optical fiber-based photocathode

    NASA Astrophysics Data System (ADS)

    Cǎsǎndruc, Albert; Bücker, Robert; Kassier, Günther; Miller, R. J. Dwayne

    2016-08-01

    We present the design of a back-illuminated photocathode for electron diffraction experiments based on an optical fiber, and experimental characterization of emitted electron bunches. Excitation light is guided through the fiber into the experimental vacuum chamber, eliminating typical alignment difficulties between the emitter metal and the optical trigger and position instabilities, as well as providing reliable control of the laser spot size and profile. The in-vacuum fiber end is polished and coated with a 30 nm gold (Au) layer on top of 3 nm of chromium (Cr), which emits electrons by means of single-photon photoemission when femtosecond pulses in the near ultraviolet (257 nm) are fed into the fiber on the air side. The emission area can be adjusted to any value between a few nanometers (using tapered fibers) and the size of a multi-mode fiber core (100 μm or larger). In this proof-of-principle experiment, two different types of fibers were tested, with emission spot diameters of 50 μm and 100 μm, respectively. The normalized thermal electron beam emittance (TE) was measured by means of the aperture scan technique, and a TE of 4.0 π nm was measured for the smaller spot diameter. Straightforward enhancements to the concept allowed to demonstrate operation in an electric field environment of up to 7 MV/m.

  8. Fiber Optics - An Aegis Experience

    NASA Astrophysics Data System (ADS)

    Saige, Vance

    1990-02-01

    The Navy has been involved in the exploitation of fiber optics over the decade for which many of the developmental efforts have represented a significant breakthrough in technology and also for applications. Significant among the Navy initiatives has been the effort of the AEGIS Program Office of the Naval Sea Systems Command located in Washington D.C. This paper presents some of these developmental efforts coming out of initiatives. The efforts lead to the implementation of some demonstrations aboard the AEGIS Cruisers for shipboard evaluation purposes. The program objectives were met and the efforts were considered successful demonstrations of the performance of fiber optics aboard a Navy ship.

  9. Optical-fiber sensors challenge the competition

    NASA Astrophysics Data System (ADS)

    Giallorenzi, T. G.; Bucaro, J. A.; Dandridge, A.; Cole, J. H.

    1986-09-01

    Optical-fiber sensors which are based on intensity modulation of light are examined. The optical-fiber sensors consists of a glass core, a cladding, a light emitting diode or laser, and a photodetector, and are applicable to measuring instruments, medical probes, control systems, and military surveillance and navigation systems. The designs and capabilities of microbend sensors and interferometric fiber sensors are described. The development of fiber temperature sensors and fiber-optic acceleration sensors is considered. Procedures for measuring flow and liquid level with fiber sensors are discussed. The utilization of fiber-optic sensors in hydrophones, gyroscopes, and magnetometers is being studied.

  10. Fiber-optic currents measurements

    NASA Astrophysics Data System (ADS)

    Forman, P. R.; Looney, L. D.; Tabaka, L. J.

    Polarization maintaining pigtailed laser diodes have greatly increased the ease with which fiber-optic sensors for Faraday current measurements on large pulsed experiments can be deployed. 670, 830, and 1300 nm units are readily available. Such diode lasers can easily be mounted in an RF shielded box along with the simple electronics and batteries to power them. Our units measure 16.5 x 8 x 6 cm. and have a single external control; an on off switch. They use two 1.5 volt C cell batteries. By using an LT1073 chip in the electronics, the batteries are an energy source rather than a voltage source. These units can provide 100 mA drive to a LT015MD laser diode so that 1 mW of 830 nm light exits the fiber pigtail for up to 23 hours with no detectable droop in power. For the sensor element, twisted single mode low birefringence fibers are wrapped around the region of interest. The fiber pigtail is fused to the sensor section so changes in alignment are avoided. The light exiting the fiber sensor section is immediately analyzed by a compact, 3 x 3.5 x 5 cm, bulk optical unit which outputs quadrature optical signals into two multimode fibers leading to detectors in a screen room. The system is thus completely free of ground loops and is as immune to noise as the screen room. These sensors have the usual advantages claimed for them and the all dielectric feature was the original reason for their use on our experiments. The ease of deployment however is not usually cited. On our Pegasus 2 experiment, the need arose for a total current measurement at the main header of the capacitor banks. A single turn of optical fiber was easily strung in a 6.4 m diameter circle and attached to laser and analyzer in a few hours.

  11. Fiber-optic currents measurements

    SciTech Connect

    Forman, P.R.; Looney, L.D.; Tabaka, L.J.

    1993-03-01

    Polarization maintaining pigtailed laser diodes have greatly increased the ease with which fiber-optic sensors for Faraday current measurements on large pulsed experiments can be deployed. 670, 830, and 1300 nm units are readily available. Such diode lasers can easily be mounted in an RF shielded box along with the simple electronics and batteries to power them. Our units measure 16.5 {times} 8 {times} 6 cm. and have a single external control; an on off switch. They use two 1.5 volt ``C`` cell batteries. By using an LT1073 chip in the electronics the batteries are an energy source rather than a voltage source. These units can provide 100 mA drive to a LT015MD laser diode so that 1 mW of 830 nm fight exits the fiber pigtail for up to 23 hours with no detectable droop in power. For the sensor element twisted single mode low birefringence fibers are wrapped around the region of interest. The fiber pigtail is fused to the sensor section so changes in alignment are avoided. The light exiting the fiber sensor section is immediately analyzed by a compact, 3 {times} 3.5 {times} 5 cm, bulk optical unit which outputs quadrature optical signals into two multimode fibers leading to detectors in a screen room. The system is thus completely free of ground loops and is as immune to noise as the screen room. These sensors have the usual advantages claimed for them and the all dielectric feature was the original reason for their use on our experiments. The ease of deployment however is not usually cited. On our Pegasus II experiment the need arose for a total current measurement at the main header of the capacitor banks. A single turn of optical fiber was easily strung in a 6.4 m diameter circle and attached to laser and analyzer in a few hours.

  12. Fiber-Optic Differential Displacement Sensor

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping

    1996-01-01

    Dual fiber-optic sensor measures small relative displacements of two proximate objects along common surface. Dual sensor comprises two fiber-optic sensors in differential configuration increasing sensitivity to displacement while decreasing sensitivity to thermal expansion and contraction.

  13. Sealed fiber-optic bundle feedthrough

    DOEpatents

    Tanner, Carol E.

    2002-01-01

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

  14. Embedding Optical Fibers In Cast Metal Parts

    NASA Technical Reports Server (NTRS)

    Gibler, William N.; Atkins, Robert A.; Lee, Chung E.; Taylor, Henry F.

    1995-01-01

    Use of metal strain reliefs eliminates breakage of fibers during casting process. Technique for embedding fused silica optical fibers in cast metal parts devised. Optical fiber embedded in flange, fitting, or wall of vacuum or pressure chamber, to provide hermetically sealed feedthrough for optical transmission of measurement or control signals. Another example, optical-fiber temperature sensor embedded in metal structural component to measure strain or temperature inside component.

  15. High pressure fiber optic sensor system

    DOEpatents

    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.

  16. Applications of fiber optics in physical protection

    SciTech Connect

    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.

  17. Multiple object fiber optic spectroscopy

    NASA Technical Reports Server (NTRS)

    Hill, J. M.; Angel, J. R. P.; Scott, J. S.; Lindley, D.; Hintzen, P.

    1982-01-01

    The Steward Observatory of the University of Arizona employs short optical fiber lengths to bring light from galaxy images at the 2.3 m telescope's focus to a line along a spectrograph slit, thereby obtaining simultaneous spectra of many objects of the field of view. After describing this instrument, attention is given to the development of an improved version through which efficiency gains will be obtained by remotely positioning the fibers under computer control and by correctly matching fiber outputs to the spectrograph optics. A CCD will replace the presently employed image tube and photographic plate detector system, in order to permit sky subtraction, yield increased dynamic range, and provide more accurate wavelength calibration due to the detector's fixed format.

  18. A chip of fiber optical trap

    NASA Astrophysics Data System (ADS)

    Su, Heming; Hu, Huizhu; Zhang, Lei; Ge, Xiaojia; Shen, Yu

    2016-10-01

    A chip of fiber optical trap paves the way to realize the miniaturization and portability of devices based on dual beam optical trap, without loss of stability. We have designed two types of chip of fiber optical trap according to our theoretical simulation. The first one integrates dual beam optical trap with microfluidic chip, called a chip of semi-sealing fiber optical trap. It is generally used in chemical, biological, medical and other high-throughput experiments. The second one is a chip of full-sealing fiber optical trap. It is used to measure precisely the coefficient of viscosity or the Brownian movement of micro-object's in liquid. This paper focuses on the chip of fiber optical trap. We present two types of chips of fiber optical trap and detail their designs, fabrication and validation. The chip of semi-sealing fiber optical trap is integrated with optical fiber and microfluidic chip made of polydimethylsiloxane (PDMS). We have achieved the micro-sized alignment of optical paths and the trapping of micro-sized particles in the chip of semi-sealing fiber optical trap. In addition, it is easy to fabrication and clean. The chip of full-sealing fiber optical trap was based on a cubic micro-cavity made by a rectangular capillary tube and sealed by PDMS. We have achieved micro-sized alignment accuracy, high trapping efficiency and better trapping stability in the chip of full-sealing fiber optical trap as well.

  19. Passive Fiber Optic Gyro Study.

    DTIC Science & Technology

    1979-10-01

    34. FORWORD The report summarizes the principles of operation of the passive fiber optic gyro. It starts with a discussion of the Sagnac effect and...polarization and the angle of the " fast " axis varied nonlinearly and that the two effects are partially independent. Based on tests with a 200 meter length of

  20. Adjustable Optical-Fiber Attenuator

    NASA Technical Reports Server (NTRS)

    Buzzetti, Mike F.

    1994-01-01

    Adjustable fiber-optic attenuator utilizes bending loss to reduce strength of light transmitted along it. Attenuator functions without introducing measurable back-reflection or insertion loss. Relatively insensitive to vibration and changes in temperature. Potential applications include cable television, telephone networks, other signal-distribution networks, and laboratory instrumentation.

  1. Fiber Optics: Deregulate and Deploy.

    ERIC Educational Resources Information Center

    Suwinski, Jan H.

    1993-01-01

    Describes fiber optic technology, explains its use in education and commercial settings, and recommends regulations and legislation that will speed its use to create broadband information networks. Topics discussed include distance learning; interactive video; costs; and the roles of policy makers, lawmakers, public advocacy groups, and consumers.…

  2. Strain sensing using optical fibers

    NASA Technical Reports Server (NTRS)

    Houghton, Richard; Hiles, Steven

    1994-01-01

    The main source of attenuation which will be studied is the optical fiber's sensitivity to bending at radii that are much larger than the radius of the fiber. This type of environmental attenuation causes losses that are a function of the severity of the bend. The average attenuation caused by bending varies exponentially with the bend radius. There are many different fibers, sources, and testing equipment available. This thesis describes tests that were performed to evaluate the variables that effect bending related attenuation and will discuss the consistency of the results. Descriptions and comparisons will be made between single mode and multimode fibers as well as instrumentation comparisons between detection equipment. Detailed analysis of the effects of the whispering gallery mode will be performed along with theorized methods for characterization of these modes.

  3. Career Directions--Fiber Optic Installer

    ERIC Educational Resources Information Center

    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…

  4. Overview of Fiber-Optical Sensors

    NASA Technical Reports Server (NTRS)

    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.

  5. Aircraft fiber optic structural health monitoring

    NASA Astrophysics Data System (ADS)

    Mrad, Nezih

    2012-06-01

    Structural Health Monitoring (SHM) is a sought after concept that is expected to advance military maintenance programs, increase platform operational safety and reduce its life cycle cost. Such concept is further considered to constitute a major building block of any Integrated Health Management (IHM) capability. Since 65% to 80% of military assets' Life Cycle Cost (LCC) is devoted to operations and support (O&S), the aerospace industry and military sectors continue to look for opportunities to exploit SHM systems, capability and tools. Over the past several years, countless SHM concepts and technologies have emerged. Among those, fiber optic based systems were identified of significant potential. This paper introduces the elements of an SHM system and investigates key issues impeding the commercial implementation of fiber optic based SHM capability. In particular, this paper presents an experimental study of short gauge, intrinsic, spectrometric-based in-fiber Bragg grating sensors, for potential use as a component of an SHM system. Fiber optic Bragg grating sensors are evaluated against resistance strain gauges for strain monitoring, sensitivity, accuracy, reliability, and fatigue durability. Strain field disturbance is also investigated by "embedding" the sensors under a photoelastic coating in order to illustrate sensor intrusiveness in an embedded configuration.

  6. Erbium Doped Fiber Optic Gravimeter

    NASA Astrophysics Data System (ADS)

    Pérez-Sánchez, G. G.; Pérez-Torres, J. R.; Flores-Bravo, J. A.; Álvarez-Chávez, J. A.; Martínez-Piñón, F.

    2017-01-01

    Gravimeters are devices that can be used in a wide range of applications, such as mining, seismology, geodesy, archeology, geophysics and many others. These devices have great sensibility, which makes them susceptible to external vibrations like electromagnetic waves. There are several technologies regarding gravimeters that are of use in industrial metrology. Optical fiber is immune to electromagnetic interference, and together with long period gratings can form high sensibility sensors of small size, offering advantages over other systems with different technologies. This paper shows the development of an optical fiber gravimeter doped with Erbium that was characterized optically for loads going from 1 to 10 kg in a bandwidth between 1590nm to 1960nm, displaying a weight linear response against power. Later on this paper, the experimental results show that the previous described behavior can be modeled as characteristic function of the sensor.

  7. Magneto-Optic Field Coupling in Optical Fiber Bragg Gratings

    NASA Technical Reports Server (NTRS)

    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.

  8. Coherent Fiber Optic Links

    DTIC Science & Technology

    1990-12-01

    local oscillator to achieve a receiver penalty of 1dB at a BER of 10- 9. REFERENCES [1] G Jacobsen and I Garrett: "Theory for heterodyne optical ASK...34Costas loop analysis for coherent optical receivers", Electronics Letters, 1986, Vol. 22, pp.394-396. [3] I Garrett and G Jacobsen : "Theoretical...DC block must be inserted and threshold on the BER set adjusted to zero volts. -5.21- Data [nj] POW Coherent Modulationcircuit op~ arn Diectn,, anua Rx

  9. Fiber Optic Sensing: Prototype Results

    NASA Astrophysics Data System (ADS)

    Ortiz Martin, Jesus; Gonzalez Torres, Jose

    2015-09-01

    Airbus DS Crisa has been developing an interrogator of Fiber Bragg Grating sensors [1], aimed at measuring, mainly, temperature and strain by means of fiber optic links. This activity, funded by Airbus DS Crisa, ESA and HBM Fibersensing, finalizes with the manufacturing of a prototype. The present paper describes in detail the main outcomes of the testing activities of this prototype. At the moment of writing the paper all the functional tests have been concluded. The environmental tests, thermal and mechanical, will be conducted with the FOS interrogator forming part of the RTU2015, described in [2].

  10. Thermal lensing in optical fibers.

    PubMed

    Dong, Liang

    2016-08-22

    Average powers from fiber lasers have reached the point that a quantitative understanding of thermal lensing and its impact on transverse mode instability is becoming critical. Although thermal lensing is well known qualitatively, there is a general lack of a simple method for quantitative analysis. In this work, we first conduct a study of thermal lensing in optical fibers based on a perturbation technique. The perturbation technique becomes increasingly inaccurate as thermal lensing gets stronger. It, however, provides a basis for determining a normalization factor to use in a more accurate numerical study. A simple thermal lensing threshold condition is developed. The impact of thermal lensing on transverse mode instability is also studied.

  11. Material dispersion in optical fibers.

    PubMed

    Wemple, S H

    1979-01-01

    A three-parameter description of optical fiber material dispersion is proposed which fits the available data and reveals the key roles played by bond length, lattice structure, chemical valence, average energy gap, and atomic mass. Using broadly applicable trends in electronic and phonon oscillator strengths, simple expressions are deduced for material dispersion including the zero crossover wavelength lambda(c). These results impose severe constraints on fiber design which essentially limit the possibilities for significantly improving on pure silica to sulfates (particularly Li(2)SO(4)) and to BeF(2). The predicted value of lambda(c) for the latter material is 1.05 microm.

  12. Polymer microstructured optical fibers for terahertz wave guiding.

    PubMed

    Ung, Bora; Mazhorova, Anna; Dupuis, Alexandre; Rozé, Mathieu; Skorobogatiy, Maksim

    2011-12-12

    We outline the most recent technological advancements in the design, fabrication and characterization of polymer microstructured optical fibers (MOFs) for applications in the terahertz waveband. Focusing on specific experimental demonstrations, we show that polymer optical fibers provide a very flexible route towards THz wave guiding. Crucial incentives include the large variety of the low-cost and relatively low absorption loss polymers, the facile fiber preform fabrication by molding, drilling, stacking and extrusion, and finally, the simple fabrication through fiber drawing at low forming temperatures.

  13. Fiber Optic Repair and Maintainability (FORM) Program Progresses

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Advanced aircraft will employ fiber-optic interconnection components to transmit information from airframe and propulsion sensors to the flight control computers. Although these optical interconnects have been rigorously tested under laboratory conditions to determine their operating and environmental limits, there is concern as to their repairability and maintainability when placed in actual service. The Fiber Optic Repair and Maintainability (FORM) flight test program will provide data to enable designers to improve these fiber-optic interconnection systems for the next generation of aircraft. FORM is identifying critical problems in installing, maintaining, testing, and repairing fiber-optic interconnection systems in an operational avionics environment. This program is a cooperative Government/industry effort to evaluate optical component acceptability and installation techniques for aircraft.

  14. Generalized fiber Fourier optics.

    PubMed

    Cincotti, Gabriella

    2011-06-15

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

  15. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John

    1999-01-01

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

  16. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1999-04-06

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

  17. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John

    1995-01-01

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

  18. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1995-05-30

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

  19. Glass-clad semiconductor core optical fibers

    NASA Astrophysics Data System (ADS)

    Morris, Stephanie Lynn

    Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine. As research into these fibers has progressed, it has become evident that excessive losses are limiting performance and so greater understanding of the underlying materials science, coupled with advances in fiber processing, is needed. More specifically, the semiconductor core fibers possess three performance-limiting characteristics that need to be addressed: (a) thermal expansion mismatches between crystalline core and glass cladding that lead to cracks, (b) the precipitation of oxide species in the core upon fiber cooling, which results from partial dissolution of the cladding glass by the core melt, and (c) polycrystallinity; all of which lead to scattering and increased transmission losses. This dissertation systematically studies each of these effects and develops both a fundamental scientific understanding of and practical engineering methods for reducing their impact. With respect to the thermal expansion mismatch and, in part, the dissolution of oxides, for the first time to our knowledge, oxide and non-oxide glass compositions are developed for a series of semiconductor cores based on two main design criteria: (1) matching the thermal expansion coefficient between semiconductor core and glass cladding to minimize cracking and (2) matching the viscosity-temperature dependences, such that the cladding glass draws into fiber at a temperature slightly above the melting point of the semiconductor in order to minimize dissolution and improve the fiber draw process. The x[Na 2O:Al2O3] + (100 - 2x)SiO2 glass compositional family was selected due to the ability to tailor the glass properties to match the aforementioned targets through slight variations in composition and adjusting the ratios of bridging and non-bridging oxygen

  20. Optical fibers for high-resolution in vivo microendoscopic fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Oh, Gyungseok; Chung, Euiheon; Yun, Seok H.

    2013-12-01

    Optical fiber-based high-resolution fluorescence imaging techniques have promising applications in clinical practice and preclinical research using animals. Here we review the instrumentation and applications of microendoscopy based on various types of optical fibers. Single-mode fibers and double-clad fibers have been widely used for delivering light from light sources to tissues and collecting light from tissues to photodetectors. Coherent fiber bundles, cylindrical graded-index lenses, and multi-mode fibers have been employed in both beam-scanning and non-scanning microscopy. With continuing advances of optical fiber technologies, further innovations in optical microendoscopy are expected.

  1. LDEF fiber optic exposure experiment

    NASA Technical Reports Server (NTRS)

    Johnston, Alan R.; Bergman, Larry A.; Hartmayer, Ron

    1991-01-01

    Ten fiber optic cable samples of different types were exposed in low Earth orbit for over 5.5 years on the Long Duration Exposure Facility (LDEF). Four of the samples were mounted externally, and the remaining six were internal, under approximately .5 gc/sq m of aluminum. The experiment was recovered in January of 1990, and laboratory evaluation of the effects of the exposure has continued since. An increase in loss, presumed to be from radiation darkening, aging effects on polymer materials used in cabling, unique contamination effects on connector terminations, and micrometeoroid impacts were observed on some of the samples. In addition, the dependence of sample loss was measured as a function of temperature before and after the flight. All cable samples were functional, and the best exhibited no measurable change in performance, indicating that conventional fiber optic cables can perform satisfactorily in spacecraft. Experimental results obtained to date will be presented and discussed.

  2. A compact optical fiber positioner

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    In this paper, a compact optical fiber positioner is proposed, which is especially suitable for small scale and high density optical fiber positioning. Based on the positioning principle of double rotation, positioner's center shaft depends on planetary gear drive principle, meshing with the fixed annular gear central motor gear driving device to rotate, and the eccentric shaft rotated driving by a coaxial eccentric motor, both center and the eccentric shaft are supported by a rolling bearings; center and eccentric shaft are both designed with electrical zero as a reference point, and both of them have position-limiting capability to ensure the safety of fiber positioning; both eccentric and center shaft are designed to eliminating clearance with spring structure, and can eliminate the influence of gear gap; both eccentric and center motor and their driving circuit can be installed in the positioner's body, and a favorable heat sink have designed, the heat bring by positioning operation can be effectively transmit to design a focal plane unit through the aluminum component, on sleeve cooling spiral airway have designed, when positioning, the cooling air flow is inlet into install hole on the focal plate, the cooling air flow can effectively take away the positioning's heat, to eliminate the impact of the focus seeing. By measuring position device's sample results show that: the unit accuracy reached 0.01mm, can meet the needs of fiber positioning.

  3. Advanced Electro-Optic Surety Devices

    SciTech Connect

    Watterson, C.E.

    1997-05-01

    The Advanced Electro-Optic Surety Devices project was initiated in march 1991 to support design laboratory guidance on electro-optic device packaging and evaluation. Sandia National Laboratory requested AlliedSignal Inc., Kansas City Division (KCD), to prepare for future packaging efforts in electro-optic integrated circuits. Los Alamos National Laboratory requested the evaluation of electro-optic waveguide devices for nuclear surety applications. New packaging techniques involving multiple fiber optic alignment and attachment, binary lens array development, silicon V-groove etching, and flip chip bonding were requested. Hermetic sealing of the electro-optic hybrid and submicron alignment of optical components present new challenges to be resolved. A 10-channel electro-optic modulator and laser amplifier were evaluated for potential surety applications.

  4. MX optical fiber communication system

    NASA Astrophysics Data System (ADS)

    Keiser, G.

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

  5. Polyimide-coated embedded optical fiber sensors

    NASA Astrophysics Data System (ADS)

    Nath, Dilip K.; Nelson, Gary W.; Griffin, Stephen E.; Harrington, C. T.; He, Yi-Fei; Reinhart, Lawrence J.; Paine, D. C.; Morse, Theodore F.

    1991-10-01

    The present paper describes the behavior of embedded optical sensor fibers in a high- temperature PEEK (polyether ether ketone) carbon fiber composite. Sheets of this material, 200 micrometers thick, were layered in alternating directions for the carbon fibers. Typically, 16 sheets were used to form 3' X 6' or 3' X 8' panels by placing the optical fibers in the middle of the `prepreg' sheets, which were then heated to the processing temperature, and subjected to a pressure of 300 psi during the cool-down phase. Since the ordinary polymeric coatings of optical fibers cannot survive the 380 degree(s)C to 400 degree(s)C processing temperature of PEEK impregnated fiber composites, all of the optical sensor fibers tested were polyimide coated. The optical, mechanical, and thermal properties are reported and it is concluded that polyimide coated fibers can withstand PEEK processing conditions.

  6. Remote Synchrotron Light Instrumentation Using Optical Fibers

    SciTech Connect

    De Santis, S.; Yin, Y.

    2009-05-04

    By coupling the emitted synchrotron light into an optical fiber, it is possible to transmit the signal at substantial distances from the light port, without the need to use expensive beamlines. This would be especially beneficial in all those cases when the synchrotron is situated in areas not easily access because of their location, or due to high radiation levels. Furthermore, the fiber output can be easily switched, or even shared, between different diagnostic instruments. We present the latest results on the coupling and dispersion measurements performed at the Advanced Light Source in Berkeley. In several cases, coupling synchrotron light into optical fibers can substantially facilitate the use of beam diagnostic instrumentation that measures longitudinal beam properties by detecting synchrotron radiation. It has been discussed in with some detail, how fiberoptics can bring the light at relatively large distances from the accelerator, where a variety of devices can be used to measure beam properties and parameters. Light carried on a fiber can be easily switched between instruments so that each one of them has 100% of the photons available, rather than just a fraction, when simultaneous measurements are not indispensable. From a more general point of view, once synchrotron light is coupled into the fiber, the vast array of techniques and optoelectronic devices, developed by the telecommunication industry becomes available. In this paper we present the results of our experiments at the Advanced Light Source, where we tried to assess the challenges and limitations of the coupling process and determine what level of efficiency one can typically expect to achieve.

  7. Machine Tests Optical Fibers In Flexure

    NASA Technical Reports Server (NTRS)

    Darejeh, Hadi; Thomas, Henry; Delcher, Ray

    1993-01-01

    Machine repeatedly flexes single optical fiber or cable or bundle of optical fibers at low temperature. Liquid nitrogen surrounds specimen as it is bent back and forth by motion of piston. Machine inexpensive to build and operate. Tests under repeatable conditions so candidate fibers, cables, and bundles evaluated for general robustness before subjected to expensive shock and vibration tests.

  8. Overview of NASA research in fiber optics for aircraft controls

    NASA Technical Reports Server (NTRS)

    Seng, Gary T.

    1988-01-01

    The challenge of those involved in aircraft control system hardware development is to accommodate an ever-increasing complexity in aircraft control, while limiting the size and weight of the components and improving system reliability. A technology that displays promise towards this end is fiber optics. The primary advantages of employing optical fibers, passive optical sensors and optically controlled actuators are weight/volume reduction, immunity from electromagnetic effects, high bandwidth capabilities and freedom from short circuits/sparking contacts. Since 1975, NASA Lewis has been performing in-house, contract and grant research in fiber optic sensors, high temperature electro-optic switches and fly-by-light control system architecture. Passive optical sensor development is an essential yet challenging area of work and has therefore received much attention during this period. A major effort to develop fly-by-light control system technology, known as the Fiber Optic Control System Integration (FOCSI) program, was initiated in 1985 as a cooperative effort between NASA and DOD. Phase 1 of FOCSI, completed in 1986, was aimed at the design of a fiber optic integrated propulsion/flight control system. Phase 2 will provide subcomponent and system development and system testing. In addition to a summary of the benefits of fiber optics, the FOCSI program, sensor advances, and future directions in the NASA Lewis program are discussed.

  9. Fiber optic vibration sensor using bifurcated plastic optical fiber

    NASA Astrophysics Data System (ADS)

    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.

  10. Use of optical fibers in spectrophotometry

    NASA Technical Reports Server (NTRS)

    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.

  11. Optical fiber grating tuning device and application

    NASA Astrophysics Data System (ADS)

    Luo, Fei; Yeh, T.

    2008-12-01

    A new design for tuning optical fiber grating is proposed. The fiber grating is placed in the grooves between a pair of slides, in which one end of the fiber is bonded on the bottom slide, and the other end of the fiber is bonded on the top slide, the grating section of the fiber is confined in grooves, so that the fiber grating is remaining straight without buckling during axial compressive force applied to the fiber. An actuator is used for driving slide to apply force on fiber to axially compress or stretch the fiber grating. The wavelength of the fiber grating is tuned according to applied stress on the fiber. The applications of the device include tunable fiber laser, tunable fiber filter etc.

  12. Remotely readable fiber optic compass

    DOEpatents

    Migliori, Albert; Swift, Gregory W.; Garrett, Steven L.

    1986-01-01

    A remotely readable fiber optic compass. A sheet polarizer is affixed to a magnet rotatably mounted in a compass body, such that the polarizer rotates with the magnet. The optical axis of the sheet polarizer is preferably aligned with the north-south axis of the magnet. A single excitation light beam is divided into four identical beams, two of which are passed through the sheet polarizer and through two fixed polarizing sheets which have their optical axes at right angles to one another. The angle of the compass magnet with respect to a fixed axis of the compass body can be determined by measuring the ratio of the intensities of the two light beams. The remaining ambiguity as to which of the four possible quadrants the magnet is pointing to is resolved by the second pair of light beams, which are passed through the sheet polarizer at positions which are transected by two semicircular opaque strips formed on the sheet polarizer. The incoming excitation beam and the four return beams are communicated by means of optical fibers, giving a remotely readable compass which has no electrical parts.

  13. Remotely readable fiber optic compass

    DOEpatents

    Migliori, A.; Swift, G.W.; Garrett, S.L.

    1985-04-30

    A remotely readable fiber optic compass. A sheet polarizer is affixed to a magnet rotatably mounted in a compass body, such that the polarizer rotates with the magnet. The optical axis of the sheet polarizer is preferably aligned with the north-south axis of the magnet. A single excitation light beam is divided into four identical beams, two of which are passed through the sheet polarizer and through two fixed polarizing sheets which have their optical axes at right angles to one another. The angle of the compass magnet with respect to a fixed axis of the compass body can be determined by measuring the ratio of the intensities of the two light beams. The remaining ambiguity as to which of the four possible quadrants the magnet is pointing to is resolved by the second pair of light beams, which are passed through the sheet polarizer at positions which are transected by two semicircular opaque strips formed on the sheet polarizer. The incoming excitation beam and the four return beams are communicated by means of optical fibers, giving a remotely readable compass which has no electrical parts.

  14. Fiber optic microbend phase shifter and modulator

    NASA Astrophysics Data System (ADS)

    Taylor, H. F.

    1985-09-01

    The present invention relates generally to a fiber optic phase shifter and intensity modulator and more particularly to fiber optic phase shifters and modulators that utilize a microbend transducer. The ability to shift the phase of light propagating in a single mode fiber is quite useful in fiber optic sensors and may also be used in fiber-optic communications. A conventional way to shift the phase of light propagating in a single mode fiber is by stretching the fiber. This is done by wrapping and gluing the fiber around a cylinder of piezoelectric material. When a voltage is applied to the material, the cylinder expands thereby stretching the fiber. Long lengths on the order of 10 meters of fiber and large voltages are needed to drive the piezoelectric cylinder. The ability to modulate the intensity of light propagating in a optic fiber is also useful in fiber optic communication and sensing systems. Such modulation can be performed by a device external to the fiber such as an electrooptic modulator formed in a lithium niobate crystal.

  15. Effects of fiber manipulation methods on optical fiber properties

    NASA Astrophysics Data System (ADS)

    Reynolds, Robert O.; Bechter, Andrew; Crass, Jonathan

    2016-07-01

    Optical fibers are routinely used to couple high-resolution spectrographs to modern telescopes, enabling important advantages in areas such as the search for extrasolar planets using spectroscopic radial velocity measurements of candidate stars. Optical fibers partially scramble the input illumination, and this feature enables a fiber feed to provide more uniform illumination to the spectrograph optics, thereby reducing systematic errors in radial velocity measurements. However fibers suffer from focal ratio degradation (FRD), a spreading of the beam at the output of the fiber with respect to that at the fiber input, which results in losses in throughput and resolution. Modal noise, a measurement uncertainty caused by inherent fiber properties and evident as a varying spatial intensity at the fiber exit plane, reduces the signal to noise ratio in the data. Devices such as double scramblers are often used to improve scrambling, and better fiber end preparation can mitigate FRD. Many instruments agitate the fiber during an observation to reduce modal noise, and stretching the fiber during use has been shown to offer a greater reduction in that noise. But effects of agitation and stretching on fiber parameters such as total transmission and focal ratio degradation have not been adequately studied. In this paper we present measurements of transmission loss and focal ratio degradation for both agitated and stretched fibers.

  16. Fiber-Optic Ammonia Sensors

    NASA Technical Reports Server (NTRS)

    Carter, Michael T.

    2003-01-01

    Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity. This work was done by Michael T. Carter

  17. Embedded fiber-optic sensing for accurate internal monitoring of cell state in advanced battery management systems part 2: Internal cell signals and utility for state estimation

    NASA Astrophysics Data System (ADS)

    Ganguli, Anurag; Saha, Bhaskar; Raghavan, Ajay; Kiesel, Peter; Arakaki, Kyle; Schuh, Andreas; Schwartz, Julian; Hegyi, Alex; Sommer, Lars Wilko; Lochbaum, Alexander; Sahu, Saroj; Alamgir, Mohamed

    2017-02-01

    A key challenge hindering the mass adoption of Lithium-ion and other next-gen chemistries in advanced battery applications such as hybrid/electric vehicles (xEVs) has been management of their functional performance for more effective battery utilization and control over their life. Contemporary battery management systems (BMS) reliant on monitoring external parameters such as voltage and current to ensure safe battery operation with the required performance usually result in overdesign and inefficient use of capacity. More informative embedded sensors are desirable for internal cell state monitoring, which could provide accurate state-of-charge (SOC) and state-of-health (SOH) estimates and early failure indicators. Here we present a promising new embedded sensing option developed by our team for cell monitoring, fiber-optic (FO) sensors. High-performance large-format pouch cells with embedded FO sensors were fabricated. This second part of the paper focuses on the internal signals obtained from these FO sensors. The details of the method to isolate intercalation strain and temperature signals are discussed. Data collected under various xEV operational conditions are presented. An algorithm employing dynamic time warping and Kalman filtering was used to estimate state-of-charge with high accuracy from these internal FO signals. Their utility for high-accuracy, predictive state-of-health estimation is also explored.

  18. Optical fiber sensor for allergen detection

    NASA Astrophysics Data System (ADS)

    Bendoula, R.; Wacogne, B.; Giust, R.; Cherioux, F.; Sandoz, P.; Gharbi, T.

    2005-08-01

    The sensor is dedicated to the detection of allergens. We use a biochemical reaction in the vicinity of the core of an optical fiber which modifies the propagation conditions of the optical wave by evanescent coupling. The detection involves a intrinsic optical fiber Fabry-Perot interferometer.

  19. Optical Fibers Would Sense Local Strains

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio O.; Rogowski, Robert S.

    1994-01-01

    Proposed fiber-optic transducers measure local strains. Includes lead-in and lead-out lengths producing no changes in phase shifts, plus short sensing length in which phase shift is sensitive to strain. Phase shifts in single-mode fibers vary with strains. In alternative version, multiple portions of optical fiber sensitive to strains characteristic of specific vibrational mode of object. Same principle also used with two-mode fiber.

  20. Great prospects for fiber optics sensors

    NASA Technical Reports Server (NTRS)

    Hansen, T. E.

    1983-01-01

    Fiber optic sensors provide noise immunity and galvanic insulation at the measurement point. Interest in such sensors is increasing for these reasons. In the United States sales are expected to increase from 12 million dollars in 1981 to 180 million in 1991. Interferometric sensors based on single modus fibers deliver extremely high sensitivity, while sensors based on multi-modus fibers are more easily manufactured. The fiber optic sensors which are available today are based on point measurements. Development of fiber optic sensors in Norway is being carried out at the Central institute and has resulted in the development of medical manometers which are now undergoing clinical testing.

  1. Optical fiber gas sensor development and application

    NASA Astrophysics Data System (ADS)

    Jin, W.; Ho, H. L.

    2008-12-01

    This paper reports recent development and application of optical fiber gas sensors using absorption spectroscopy, including open-path gas sensors using fiber coupled micro-optic cells and photonic bandgap (PBG) fibers. A fiber-optic sensor system capable of detecting dissolved fault gases in oil-insulated equipment in power industry is presented. The gases include methane (CH4), acetylene (C2H2) and ethylene (C2H4). In addition, the development of gas sensor using PBG fiber will be reported.

  2. Properties and reliability of improved large acceptance optical fibers

    NASA Astrophysics Data System (ADS)

    Skutnik, Bolesh J.; Smith, Cheryl; Moran, Kelly; Bakhshpour, Kevin

    2006-02-01

    The high power diode laser systems with their laser diode bars and arrays not only require special fibers to couple directly to the diode emitters, but also require special fibers to couple from the laser to the application sites. These power delivery fibers are much larger than the internal fibers, but must be flexible, and have not only good strength but also good fatigue behavior. This is particularly important for industrial systems using robotic arms or robots to apply the high power laser energy to the treatment site. The optical properties of hard plastic clad silica (HPCS) fibers are well suited for the needs of delivery of high power from diode laser bars and arrays to an application site. New formulations for HPCS fibers have been developed which have demonstrated fibers with good mechanical strength in preliminary tests. A systematic study has been undertaken to determine the strength and fatigue behavior of three 'new' HPCS fibers and to compare them with results for earlier HPCS fibers. Benefits of stronger median dynamic strengths and tighter flaw distributions have been found. Short to medium length time to failure results, indicate that the static fatigue parameters of the new high numerical aperture (NA) optical fibers are at least as good as those for standard NA HPCS fibers, which is an advance from previous results on the older formulation clad fibers.

  3. Fiber Optic Detector For Liquid Chemical Leaks

    NASA Astrophysics Data System (ADS)

    Luukkala, Mauri; Raatikainen, Pekka; Salo, Olli

    1989-10-01

    This paper describes a simple and economical sensor which employs fiber optics to detect the presence of hazardous liquid chemicals, particularly undiluted hydrocarbons. The device is best suited to monitor the interstitial space of double walled underground storage tanks. Because the sensor is plastic and is situated at the end of a passive and insulating optical fiber the sensor can be considered inherently safe. The optical fiber used for this device can be up to several hundred meters long.

  4. Fiber optic multimode displacement sensor

    NASA Astrophysics Data System (ADS)

    Fisher, Karl A.; Jarzynski, Jacek

    1996-04-01

    An underwater Optical Motion Sensor (OMS) based on a design first presented by W. B. Spillman, Schlieren multimode fiber-optic hydrophone, Applied Physics Letters 37(2), 15 July 1980, p. 145-146 is described. The displacement sensor uses the same acoustooptical intensity modulation mechanism as Spillman, however the sensing mechanism is isolated from the ambient fluid environment by a small cylindrical aluminum enclosure (1″ OD×3/4″). The enclosure contains an inertial mass and the fiber collimators. The inertial mass is suspended in the center of the enclosure by three small wires rigidly mounted to the walls. The mass and wires act as a cantilever beam system with a mechanical resonance near 100 Hz. The transduction mechanism consists of two opposed optical gratings aligned and positioned between the fiber collimators. One grating is mounted on the inertial mass while the other is mounted on the lower end cap of the enclosure. Relative motion between the gratings causes a modulation of the light transmitted through the gratings. The modulated beam is focused onto a photodetector and converted to electric current. The frequency response is flat from 200 Hz-9 kHz with a minimum detectable displacement of 0.002 A and the dynamic range is 136 dB. The small size and light weight give the sensor an effective density of 1.08 g/cm3 making it almost neutrally buoyant in water. This in conjunction with the performance characteristics make this sensor suitable for use in acoustical sensing applications.

  5. Advanced Adaptive Optics Technology Development

    SciTech Connect

    Olivier, S

    2001-09-18

    The NSF Center for Adaptive Optics (CfAO) is supporting research on advanced adaptive optics technologies. CfAO research activities include development and characterization of micro-electro-mechanical systems (MEMS) deformable mirror (DM) technology, as well as development and characterization of high-resolution adaptive optics systems using liquid crystal (LC) spatial light modulator (SLM) technology. This paper presents an overview of the CfAO advanced adaptive optics technology development activities including current status and future plans.

  6. Microgel photonics: a breathing cavity onto optical fiber tip

    NASA Astrophysics Data System (ADS)

    Ricciardi, A.; Aliberti, A.; Giaquinto, M.; Micco, A.; Cusano, A.

    2015-09-01

    We experimentally demonstrate a novel multifunctional optical fiber probe resulting from the integration between two rapidly emerging technologies such as Lab-on-Fiber and Microgel Photonics. The device consists of a microgel based cavity formed by metallic slabs supporting plasmonic resonances, directly integrated on the optical fiber tip. By exploiting the multiresponsivity of microgel systems, variations of temperature, PH, ionic strength, as well as molecular binding events, make the cavity to `breath', thus modulating the interference pattern in the reflection spectrum. The microgel layer can be synthetized in such a way to obtain different thicknesses, corresponding to different operating regimes, opening new avenues for the realization of advanced multifunctional nanoprobes.

  7. Fiber-optically sensorized composite wing

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  8. Ultrasound generation from an optical fiber sidewall

    NASA Astrophysics Data System (ADS)

    Zhou, Jingcheng; Wu, Nan; Bi, Siwen; Wang, Xingwei

    2016-04-01

    Ultrasound generation from an optical fiber, based on the photoacoustic principle, could have broad applications, such as ultrasound nondestructive test (NDT) and biomedical ultrasound imaging. There are many advantages of these fiber-optic ultrasonic transducers, such as small size, light weight, ease of use, and immunity to electromagnetic interference. This paper will demonstrate a novel structure which the ultrasound signal is generated on the sidewall of the fiber. Two experimental configurations of the fiber-optic sidewall ultrasonic transducer are discussed. One is that a photoacoustic material is directly coated on the sidewall of the optical fiber. The other one is that the photoacoustic material is directly coated on an aluminum plate and the sidewall fiber is buried in the material. By using this novel sidewall ultrasound generator, we can effectively generate ultrasound signal at multiple, particular locations along one fiber.

  9. Coated fiber tips for optical instrumentation

    NASA Astrophysics Data System (ADS)

    Barton, John B.; Chanda, Sheetal; Locknar, Sarah A.; Carver, Gary E.

    2016-03-01

    Compact optical systems can be fabricated by integrating coatings on fiber tips. Examples include fiber lasers, fiber interferometers, fiber Raman probes, fiber based spectrometers, and anti-reflected endoscopes. These interference filters are applied to exposed tips - either connectorized or cleaved. Coatings can also be immersed within glass by depositing on one tip and connecting to another uncoated tip. This paper addresses a fiber spectrometer for multispectral imaging - useful in several fields including biomedical scanning, flow cytometry, and remote sensing. Our spectrometer integrates serial arrays of reflecting fiber tips, delay lines between these elements, and a single element detector.

  10. Sensitive fiber-optic immunoassay

    NASA Astrophysics Data System (ADS)

    Walczak, Irene M.; Love, Walter F.; Slovacek, Rudolf E.

    1991-07-01

    The principles of evanescent wave theory were applied to an immunological sensor for detecting the cardiac-specific isoenzyme creatine kinase-MB (CK-MB). The detection of the CK-MB isoenzyme is used in conjunction with the total CK measurement in the diagnosis of acute myocardial infarction. The clinical range for CK-MB is from 2-100 ng/ml. Previous work which utilized the fluorophor, Fluorescein isothiocyanate (FITC), was able to discriminate between 0 and 3 ng/ml CK-MB. Use of the fluorophor B-phycoerythrin (BPE) increased the assay sensitivity to 0.1 ng/ml CK-MB. The data was collected for 15 minutes using an optical launch and collection angle of 25 degree(s). This fiber optic based system is homogeneous and requires no subsequent washing, handling, or processing steps after exposure to the sample.

  11. Method for optical and mechanically coupling optical fibers

    DOEpatents

    Toeppen, J.S.

    1996-10-01

    A method and apparatus are disclosed for splicing optical fibers. A fluorescing solder glass frit having a melting point lower than the melting point of first and second optical fibers is prepared. The solder glass frit is then attached to the end of the first optical fiber and/or the end of the second optical fiber. The ends of the optical fibers are aligned and placed in close proximity to each other. The solder glass frit is then heated to a temperature which is lower than the melting temperature of the first and second optical fibers, but which is high enough to melt the solder glass frit. A force is applied to the first and second optical fibers pushing the ends of the fibers towards each other. As the solder glass flit becomes molten, the layer of molten solder glass is compressed into a thin layer between the first and second optical fibers. The thin compressed layer of molten solder glass is allowed to cool such that the first and second optical fibers are bonded to each other by the hardened layer of solder glass. 6 figs.

  12. Fiber-optic Michelson interferometer using an optical power divider.

    PubMed

    Imai, M; Ohashi, T; Ohtsuka, Y

    1980-10-01

    A fiber-optic interferometer consisting of a multimode fiber-optical power divider was constructed in the Michelson arrangement and applied to measure a micrometer-order displacement of the vibrating object based on an optical homodyne technique. Improvement in the sensitivity of the apparatus is discussed from the viewpoint of increasing the minimum detectable beat signal.

  13. Process, product, and waste-stream monitoring with fiber optics

    SciTech Connect

    Milanovich, F.P.; Hirschfeld, T.

    1983-10-10

    Fiber optic technology, motivated by communications and defense applications, has advanced significantly the past ten years. In particular, advances have been made in visible radiation transmission efficiency with concurrent reductions in fiber size, weight, and cost. Researchers at the Lawrence Livermore National Laboratory (LLNL) coupled these advances in fiber optic technology with analytical fluorescence analysis to establish a new technology - remote fiber fluorimetry (RFF). Laser-based RFF offers the potential to measure and monitor from one central and remote laboratory, on-line, and in near real time, trace (ppM) to substantial (g/L) concentrations of selected chemical species in typical process, product, and waste streams. The fluorimeter consists of a fluorescence or Raman spectrometer; unique coupling optics that separates input excitation (laser) radiation from return (fluorescence) radiation; a fiber optic cable; and an optrode - a terminal that interfaces the fiber to the measurement point, which is designed to respond quantitatively to a particular chemical species. At LLNL, research is underway into optrodes that measure pressure, temperature, and pH and those that detect and quantify various actinides, sulfates, inorganic chloride, hydrogen sulfide, aldehydes, and alcohols.

  14. Analysis of bend insensitive liquid core optical fiber for broadband network and fiber-to-the-home applications

    NASA Astrophysics Data System (ADS)

    Palodiya, Vikram; Raghuwanshi, Sanjeev Kumar

    2016-02-01

    In this paper, we analyze the guided properties of liquid core optical fibers for fiber-to-thehome application. Fiber to the Home is advance technology to give unlimited bandwidth and high speed broadband network for communication. Fiber to the Home technology refers to the installation and use of bend insensitive optical fiber cables. The liquid core optical fiber has a simple core and cladding structure. This fiber achieves high relative refractive index difference among the core and cladding is proving to be bending insensitive. The single mode condition and the group velocity dispersion, mode field diameter and the bending loss of single mode fiber are studied theoretically. Compare with traditional silica optical fiber. Liquid core optical fiber has much smaller bending loss of than traditional silica fibers. Liquid core optical fiber shows unique properties, such as more confided guided mode, low bending loss and large non linear parameters in the visible and infrared region. This type of fiber used in fiber -to-the-home applications, Broadband network and also for sensing applications.

  15. Waveguide Studies for Fiber Optics and Optical Signal Processing Applications.

    DTIC Science & Technology

    1980-04-01

    beam expander is shown in Fig. 2 -i. The beam, which is expanded to approximately 100 Wm, can be deflected acousto - optically to make a spectrum analyzer...3 2 . DBR Lasers for Fiber Optics and Optical Signal Processing Sources ......... ................. 4 4. Studies of LiNbO 3...6 Chapter 1. Wave Beam Expansion ....... ............. 9 Chapter 2 . DBR Lasers for Fiber Optics and Optical Signal Processing Sources

  16. Online fiber-optic spectrophotometry

    SciTech Connect

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

    1989-01-01

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

  17. Interferometric optical fiber microcantilever beam biosensor

    NASA Astrophysics Data System (ADS)

    Wavering, Thomas A.; Meller, Scott A.; Evans, Mishell K.; Pennington, Charles; Jones, Mark E.; VanTassell, Roger; Murphy, Kent A.; Velander, William H.; Valdes, E.

    2000-12-01

    With the proliferation of biological weapons, the outbreak of food poisoning occurrences, and the spread of antibiotic resistant strains of pathogenic bacteria, the demand has arisen for portable systems capable of rapid, specific, and quantitative target detection. The ability to detect minute quantities of targets will provide the means to quickly assess a health hazardous situation so that the appropriate response can be orchestrated. Conventional test results generally require hours or even several days to be reported, and there is no change for real-time feedback. An interferometric optical fiber microcantilever beam biosensor has successfully demonstrated real time detection of target molecules. The microcantilever biosensor effectively combines advanced technology from silicon micromachining, optical fiber sensor, and biochemistry to create a novel detection device. This approach utilizes affinity coatings on micromachiend cantilever beams to attract target molecules. The presence of the target molecule causes bending in the cantilever beam, which is monitored using an optical displacement system. Dose-response trials have shown measured responses at nanogram/ml concentrations of target molecules. Sensitivity is expected to extend from the nanogram to the picogram range of total captured mass as the microcantilever sensors are optimized.

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

    PubMed

    Miida, Yusuke; Matsuura, Yuji

    2013-09-23

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

  19. Optics in Microstructured and Photonic Crystal Fibers

    NASA Astrophysics Data System (ADS)

    Knight, J. C.

    2008-10-01

    The development of optical fibers with two-dimensional patterns of air holes running down their length has reinvigorated research in the field of fiber optics. It has greatly—and fundamentally—broadened the range of specialty optical fibers, by demonstrating that optical fibers can be more "special" than previously thought. Fibers with air cores have made it possible to deliver energetic femtosecond-scale optical pulses, transform limited, as solitons, using single-mode fiber. Other fibers with anomalous dispersion at visible wavelengths have spawned a new generation of single-mode optical supercontinuum sources, spanning visible and near-infrared wavelengths and based on compact pump sources. A third example is in the field of fiber lasers, where the use of photonic crystal fiber concepts has led to a new hybrid laser technology, in which the very high numerical aperture available sing air holes have enabled fibers so short they are more naturally held straight than bent. This paper describes some of the basic physics and technology behind these developments, illustrated with some of the impressive demonstrations of the past 18 months.

  20. Designing a fiber-optic beam delivery system

    SciTech Connect

    Hunter, B.V. |; Leong, K.H.; Sanders, P.G.

    1997-03-01

    One of the advantages offered by visible and NIR lasers over CO and CO{sub 2} lasers is that they can be delivered through optical fibers. Fiber-optic beam delivery is ideal when the beam must be delivered along a complex path or processing requires complicated manipulation of the beam delivery optics. Harnessing the power of a high-power laser requires that knowledgeable and prudent choices be made when selecting the laser and its beam delivery system. The purpose of this paper is to discuss a variety of issues important when designing a beam delivery system-data obtained with high power Nd:YAG lasers will be used as illustrative examples. (1) Multimode optical fibers are used for high-power applications. The fiber imposes, to varying degrees, a structure on the beam that is different from the laser output. Fibers degrade the beam quality, although the degree of degradation is dependent on the fiber length, diameter and type. Smaller fibers tend to produce less degradation to beam quality, but the minimum usable fiber size is limited by the quality of the laser beam, focusing optic and the numerical aperture of the fiber. (2) The performance of the beam delivery system is ultimately determined by the quality of the optics. Therefore, well-corrected optics are required to realize the best possible performance. Tests with both homogeneous and GRADIUM{trademark} lenses provide insights into evaluating the benefits offered by improvements in the output optics from gradient-index, aspheric and multi-element lens systems. Additionally, these tests illustrate the origins of variable focused spot size and position with increasing laser power. (3) The physical hardware used in the beam delivery system will have several characteristics which enhance its functionality and ease of use, in addition to facilitating the use of advanced diagnostics and monitoring techniques.

  1. Optical Fiber Grating Hydrogen Sensors: A Review

    PubMed Central

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

    2017-01-01

    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. PMID:28287499

  2. Optical Fiber Grating Hydrogen Sensors: A Review.

    PubMed

    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.

  3. Cavity-enhanced spectroscopy in optical fibers.

    PubMed

    Gupta, Manish; Jiao, Hong; O'Keefe, Anthony

    2002-11-01

    Cavity-enhanced methods have been extended to fiber optics by use of fiber Bragg gratings (FBGs) as reflectors. High-finesse fiber cavities were fabricated from FBGs made in both germanium/boron-co-doped photosensitive fiber and hydrogen-loaded Corning SMF-28 fiber. Optical losses in these cavities were determined from the measured Fabry-Perot transmission spectra and cavity ring-down spectroscopy. For a 10-m-long single-mode fiber cavity, ring-down times in excess of 2 ms were observed at 1563.6 nm, and individual laser pulses were resolved. An evanescent-wave access block was produced within a fiber cavity, and an enhanced sensitivity to optical loss was observed as the external medium's refractive index was altered.

  4. Optical fiber sensors for harsh environments

    DOEpatents

    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.

  5. Fiber Optics: A New World of Possibilities in Light.

    ERIC Educational Resources Information Center

    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)

  6. Electrothermal MEMS fiber scanner for optical endomicroscopy.

    PubMed

    Seo, Yeong-Hyeon; Hwang, Kyungmin; Park, Hyeon-Cheol; Jeong, Ki-Hun

    2016-02-22

    We report a novel MEMS fiber scanner with an electrothermal silicon microactuator and a directly mounted optical fiber. The microactuator comprises double hot arm and cold arm structures with a linking bridge and an optical fiber is aligned along a silicon fiber groove. The unique feature induces separation of resonant scanning frequencies of a single optical fiber in lateral and vertical directions, which realizes Lissajous scanning during the resonant motion. The footprint dimension of microactuator is 1.28 x 7 x 0.44 mm3. The resonant scanning frequencies of a 20 mm long optical fiber are 239.4 Hz and 218.4 Hz in lateral and vertical directions, respectively. The full scanned area indicates 451 μm x 558 μm under a 16 Vpp pulse train. This novel laser scanner can provide many opportunities for laser scanning endomicroscopic applications.

  7. Assessment of fiber optic pressure sensors

    SciTech Connect

    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.

  8. Fiber optic sensors for gas turbine control

    NASA Technical Reports Server (NTRS)

    Shu, Emily Yixie (Inventor); Brown, Dale Marius (Inventor); Petrucco, Louis Jacob (Inventor); Lovett, Jeffery Allan (Inventor); Daum, Wolfgang (Inventor); Dunki-Jacobs, Robert John (Inventor)

    2003-01-01

    An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.

  9. Triboluminescent Fiber-Optic Sensors Measure Stresses

    NASA Technical Reports Server (NTRS)

    Rogowski, Robert S.

    1994-01-01

    Triboluminescence exploited in fiber-optic sensor system for measuring changes in pressures, strains, vibrations, and acoustic emissions, in structural members. Sensors embedded in members for in situ monitoring of condition of structure. System passive in sense no source of radiation required to interrogate optical fiber. Technique has potential for wide range of applications in which detection and measurement of structural stress required.

  10. Fiber optic sensors for gas turbine control

    NASA Technical Reports Server (NTRS)

    Shu, Emily Yixie (Inventor); Petrucco, Louis Jacob (Inventor); Daum, Wolfgang (Inventor)

    2005-01-01

    An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.

  11. Fiber optic sensors for gas turbine control

    NASA Technical Reports Server (NTRS)

    Shu, Emily Yixie (Inventor); Brown, Dale Marius (Inventor); Petrucco, Louis Jacob (Inventor); Lovett, Jeffery Allan (Inventor); Daum, Wolfgang (Inventor); Dunki-Jacobs, Robert John (Inventor)

    1999-01-01

    An apparatus for detecting flashback occurrences in a premixed combustor system having at least one fuel nozzle includes at least one photodetector and at least one fiber optic element coupled between the at least one photodetector and a test region of the combustor system wherein a respective flame of the fuel nozzle is not present under normal operating conditions. A signal processor monitors a signal of the photodetector. The fiber optic element can include at least one optical fiber positioned within a protective tube. The fiber optic element can include two fiber optic elements coupled to the test region. The optical fiber and the protective tube can have lengths sufficient to situate the photodetector outside of an engine compartment. A plurality of fuel nozzles and a plurality of fiber optic elements can be used with the fiber optic elements being coupled to respective fuel nozzles and either to the photodetector or, wherein a plurality of photodetectors are used, to respective ones of the plurality of photodetectors. The signal processor can include a digital signal processor.

  12. Fiber optic applications for laser polarized targets

    SciTech Connect

    Cummings, W.J.; Kowalczyk, R.S.

    1997-10-01

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

  13. Fiber-optic liquid level sensor

    DOEpatents

    Weiss, Jonathan D.

    1991-01-01

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

  14. Fiber-Optic Applications For Launch Vehicles

    NASA Astrophysics Data System (ADS)

    Curran, Mark E.; Clark, Timothy E.

    Conventional data buses, telemetry links, and sensors using wire harnesses as the transmission media suffer from numerous shortcomings, especially when utilized in spacecraft. This paper describes fiber optic networks which could be implemented in launch vehicles in the near-term. Special emphasis will be placed on the increase in reliability which fiber optics affords over conventional cable/wire approaches.

  15. Metal-Coated Optical Fibers for High Temperature Applications

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  16. Eliminating crystals in non-oxide optical fiber preforms and optical fibers

    NASA Technical Reports Server (NTRS)

    LaPointe, Michael R. (Inventor); Tucker, Dennis S. (Inventor)

    2010-01-01

    A method is provided for eliminating crystals in non-oxide optical fiber preforms as well as optical fibers drawn therefrom. The optical-fiber-drawing axis of the preform is aligned with the force of gravity. A magnetic field is applied to the preform as it is heated to at least a melting temperature thereof. The magnetic field is applied in a direction that is parallel to the preform's optical-fiber-drawing axis. The preform is then cooled to a temperature that is less than a glass transition temperature of the preform while the preform is maintained in the magnetic field. When the processed preform is to have an optical fiber drawn therefrom, the preform's optical-fiber-drawing axis is again aligned with the force of gravity and a magnetic field is again applied along the axis as the optical fiber is drawn from the preform.

  17. Fiber optic sensors for corrosion detection

    NASA Technical Reports Server (NTRS)

    Smith, Alphonso C.

    1993-01-01

    The development of fiber optic sensors for the detection of a variety of material parameters has grown tremendously over the past several years. Additionally, the potential for analytical applications of fiber optic sensors have become more widely used. New pH sensors have also been developed using fiber optic techniques to detect fluorescence characteristics from immobilized fluorogenic reagent chemicals. The primary purpose of this research was to investigate the feasibility of using fiber optic sensors to detect the presence of Al(sup 3+) ions made in the process of environmental corrosion of aluminum materials. The Al(sup 3+) ions plus a variety of other type of metal ions can be detected using analytical techniques along with fiber optic sensors.

  18. Power system applications of fiber optics

    NASA Technical Reports Server (NTRS)

    Kirkham, H.; Johnston, A.; Lutes, G.; Daud, T.; Hyland, S.

    1984-01-01

    Power system applications of optical systems, primarily using fiber optics, are reviewed. The first section reviews fibers as components of communication systems. The second section deals with fiber sensors for power systems, reviewing the many ways light sources and fibers can be combined to make measurements. Methods of measuring electric field gradient are discussed. Optical data processing is the subject of the third section, which begins by reviewing some widely different examples and concludes by outlining some potential applications in power systems: fault location in transformers, optical switching for light fired thyristors and fault detection based on the inherent symmetry of most power apparatus. The fourth and final section is concerned with using optical fibers to transmit power to electric equipment in a high voltage situation, potentially replacing expensive high voltage low power transformers. JPL has designed small photodiodes specifically for this purpose, and fabricated and tested several samples. This work is described.

  19. Optical Fiber Sensor Instrumentation for Slagging Coal Gasifiers

    SciTech Connect

    Anbo Wang; Kristie Cooper

    2008-07-19

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

  20. Hermetic fiber optic-to-metal connection technique

    DOEpatents

    Kramer, Daniel P.

    1992-09-01

    A glass-to-glass hermetic sealing technique is disclosed which can be used to splice lengths of glass fibers together. A solid glass preform is inserted into the cavity of a metal component which is then heated to melt the glass. An end of an optical fiber is then advanced into the molten glass and the entire structure cooled to solidify the glass in sealing engagement with the optical fiber end and the metal cavity. The surface of the re-solidified glass may be machined for mating engagement with another component to make a spliced fiber optic connection. The resultant structure has a helium leak rate of less than 1.times.10.sup.-8 cm.sup.3 /sec.

  1. Liquid crystal optical fibers for sensing applications

    NASA Astrophysics Data System (ADS)

    Choudhury, P. K.

    2013-09-01

    Propagation characteristics of optical fibers are greatly dependent on materials, which the guides are comprised of. Varieties of materials have been developed and investigated for their usage in fabricating optical fibers for specific applications. Within the context, a liquid crystal medium is both inhomogeneous and optically anisotropic, and fibers made of such mediums are greatly useful. Also, liquid crystals exhibit strong electro-optic behavior, which allows alternation in their optical properties under the influence of external electric fields. These features make liquid crystal fibers greatly important for optical applications. The present communication is aimed at providing a glimpse of the efficacy of liquid crystals and/or fibers made of liquid crystals, followed by the analytical investigation of wave propagation through such guides. The sustainment of modes is explored in these fibers under varying fiber dimensions, and the novelty is discussed. The case of tapered liquid crystal fibers is also briefly discussed highlighting the usefulness. Control on the dispersion characteristics of such fibers may be imposed by making the guide even more complex; the possibility of devising such options is also touched upon.

  2. Applications of Fiber Optical Sensors in Petroleum Industry

    NASA Astrophysics Data System (ADS)

    Dehghani, Maryam

    2011-12-01

    Fiber optic sensor systems have been in the oilfield for a number of years now, however, they have had many shortcomings, including high price points, which have prevented widespread adoption. We can integrate fiber optic sensors into oil and gas companies products and processes and take advantage both technically and economically of the ever more rapid advances in technology. We can design all sorts of fiber optic sensors that cover various sections of petroleum industry operations. Most of researches have been in this part of technology since that is where most of the applications are. However, the other types of sensors have also developed as well. Most of fiber optical sensors have just one or perhaps a few detectors, but some high resolution imaging systems with large detector element arrays have also developed. Some fiber optical sensors are frequently incorporated as components in larger products. They are also used independently in process control and other types of applications in petroleum industry. This paper describes various aspects of fiber optic sensors and their applications, and addresses their role in petroleum industry.

  3. Industrial applications of fiber optic sensing

    NASA Astrophysics Data System (ADS)

    Desforges, Francois X.; Blocksidge, Robert

    1996-08-01

    Thanks to the growth of the fiber optics telecommunication industry, fiber optic components have become less expensive, more reliable and well known by potential fiber optic sensor users. LEDs, optical fibers, couplers and connectors are now widely distributed and are the building blocks for the fiber optic sensor manufacturer. Additionally, the huge demand in consumer electronics of the past 10 years has provided the manufacturer with cheap and powerful programmable logic components which reduce the development time as well as the cost of the associated instrumentation. This market trend has allowed Photonetics to develop, manufacture and sell fiber optic sensors for the last 10 years. The company contribution in the fields of fiber optic gyros (4 licenses sold world wide), white light interferometry and fiber optic sensor networks is widely recognized. Moreover, its 1992 acquisition of some of the assets of Metricor Inc., greatly reinforced its position and allowed it to pursue new markets. Over the past four years, Photonetics has done an important marketing effort to better understand the need of its customers. The result of this research has fed R&D efforts towards a new generation instrument, the Metricor 2000, better adapted to the expectations of fiber optic sensors users, thanks to its unique features: (1) universality -- the system can accept more than 20 different sensors (T, P, RI, . . .). (2) scalability -- depending on the customer needs, the system can be used with 1 to 64 sensors. (3) performance -- because of its improved design, overall accuracies of 0.01% FS can be reached. (4) versatility -- its modular design enables a fast and easy custom design for specific applications. This paper presents briefly the Metricor 2000 and its family of FO probes. Then, it describes two fiber optic sensing (FOS) applications/markets where FOS have proven to be very useful.

  4. Spontaneous inelastic Rayleigh scattering in optical fibers.

    PubMed

    Okusaga, Olukayode; Cahill, James P; Docherty, Andrew; Menyuk, Curtis R; Zhou, Weimin

    2013-02-15

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

  5. Improved Optical-Fiber Temperature Sensors

    NASA Technical Reports Server (NTRS)

    Rogowski, Robert S.; Egalon, Claudio O.

    1993-01-01

    In optical-fiber temperature sensors of proposed type, phosphorescence and/or fluorescence in temperature-dependent coating layers coupled to photodetectors. Phosphorescent and/or fluorescent behavior(s) of coating material(s) depend on temperature; coating material or mixture of materials selected so one can deduce temperature from known temperature dependence of phosphorescence and/or fluorescence spectrum, and/or characteristic decay of fluorescence. Basic optical configuration same as that of optical-fiber chemical detectors described in "Making Optical-Fiber Chemical Detectors More Sensitive" (LAR-14525).

  6. Fiber optic sensors for smart taxiways

    NASA Astrophysics Data System (ADS)

    Janzen, Douglas D.; Fuerstenau, Norbert; Goetze, Wolfgang

    1995-09-01

    Fiber-optic sensors could offer advantages in the field of airport ground traffic monitoring: immunity to electromagnetic interference, installation without costly and time consuming airfield closures, and low loss, low noise optical connection between sensors and signal processing equipment. This paper describes fiber-optic sensors developed for airport taxiway monitoring and the first steps toward their installation in an experimental surface movement guidance and control system at the Braunschweig airport. Initial results obtained with fiber- optic light barriers and vibration sensors are reported. The feasibility of employing interferometric strain gauges for this application will be discussed based on sensor characteristics obtained through measurements of strain in an aircraft structure in flight.

  7. Microbend fiber-optic temperature sensor

    DOEpatents

    Weiss, J.D.

    1995-05-30

    A temperature sensor is made of optical fiber into which quasi-sinusoidal microbends have been permanently introduced. In particular, the present invention includes a graded-index optical fiber directing steady light through a section of the optical fiber containing a plurality of permanent microbends. The microbend section of the optical fiber is contained in a thermally expansive sheath, attached to a thermally expansive structure, or attached to a bimetallic element undergoing temperature changes and being monitored. The microbend section is secured to the thermally expansive sheath which allows the amplitude of the microbends to decrease with temperature. The resultant increase in the optical fiber`s transmission thus allows temperature to be measured. The plural microbend section of the optical fiber is secured to the thermally expansive structure only at its ends and the microbends themselves are completely unconstrained laterally by any bonding agent to obtain maximum longitudinal temperature sensitivity. Although the permanent microbends reduce the transmission capabilities of fiber optics, the present invention utilizes this phenomenon as a transduction mechanism which is optimized to measure temperature. 5 figs.

  8. Harsh environment fiber optic connectors/testing

    NASA Astrophysics Data System (ADS)

    Parker, Douglas A.

    2014-09-01

    Fiber optic systems are used frequently in military, aerospace and commercial aviation programs. There is a long history of implementing fiber optic data transfer for aircraft control, for harsh environment use in local area networks and more recently for in-flight entertainment systems. The advantages of fiber optics include high data rate capacity, low weight, immunity to EMI/RFI, and security from signal tapping. Technicians must be trained particularly to install and maintain fiber systems, but it is not necessarily more difficult than wire systems. However, the testing of the fiber optic interconnection system must be conducted in a standardized manner to assure proper performance. Testing can be conducted with slight differences in the set-up and procedure that produce significantly different test results. This paper reviews various options of interconnect configurations and discusses how these options can affect the performance, maintenance required and longevity of a fiber optic system, depending on the environment. Proper test methods are discussed. There is a review of the essentials of proper fiber optic testing and impact of changing such test parameters as input launch conditions, wavelength considerations, power meter options and the basic methods of testing. This becomes important right from the start when the supplier test data differs from the user's data check upon receiving the product. It also is important in periodic testing. Properly conducting the fiber optic testing will eliminate confusion and produce meaningful test results for a given harsh environment application.

  9. Experiments on room temperature optical fiber-fiber direct bonding

    NASA Astrophysics Data System (ADS)

    Hao, Jinping; Yan, Ping; Xiao, Qirong; Wang, Yaping; Gong, Mali

    2012-08-01

    High quality permanent connection between optical fibers is a significant issue in optics and communication. Studies on room temperature optical large diameter fiber-fiber direct bonding, which is essentially surface interactions of glass material, are presented here. Bonded fiber pairs are obtained for the first time through the bonding technics illustrated here. Two different kinds of bonding technics are provided-fresh surface (freshly grinded and polished) bonding and hydrophobic surface (activated by H2SO4 and HF) bonding. By means of fresh surface bonding, a bonded fiber pair with light transmitting efficiency of 98.1% and bond strength of 21.2 N is obtained. Besides, in the bonding process, chemical surface treatment of fibers' end surfaces is an important step. Therefore, various ways of surface treatment are analyzed and compared, based on atomic force microscopy force curves of differently disposed surfaces. According to the comparison, fresh surfaces are suggested as the prior choice in room temperature optical fiber-fiber bonding, owing to their larger adhesive force, attractive force, attractive distance, and adhesive range.

  10. In-fiber integrated chemiluminiscence online optical fiber sensor.

    PubMed

    Yang, Xinghua; Yuan, Tingting; Yang, Jun; Dong, Biao; Liu, Yanxin; Zheng, Yao; Yuan, Libo

    2013-09-01

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

  11. Optical fiber sensor having an active core

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

    1993-01-01

    An optical fiber is provided. The fiber is comprised of an active fiber core which produces waves of light upon excitation. A factor ka is identified and increased until a desired improvement in power efficiency is obtained. The variable a is the radius of the active fiber core and k is defined as 2 pi/lambda wherein lambda is the wavelength of the light produced by the active fiber core. In one embodiment, the factor ka is increased until the power efficiency stabilizes. In addition to a bare fiber core embodiment, a two-stage fluorescent fiber is provided wherein an active cladding surrounds a portion of the active fiber core having an improved ka factor. The power efficiency of the embodiment is further improved by increasing a difference between the respective indices of refraction of the active cladding and the active fiber core.

  12. Fiber optic D dimer biosensor

    DOEpatents

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

    1999-08-17

    A fiber optic sensor for D dimer (a fibrinolytic product) can be used in vivo (e.g., in catheter-based procedures) for the diagnosis and treatment of stroke-related conditions in humans. Stroke is the third leading cause of death in the United States. It has been estimated that strokes and stroke-related disorders cost Americans between $15-30 billion annually. Relatively recently, new medical procedures have been developed for the treatment of stroke. These endovascular procedures rely upon the use of microcatheters. These procedures could be facilitated with this sensor for D dimer integrated with a microcatheter for the diagnosis of clot type, and as an indicator of the effectiveness, or end-point of thrombolytic therapy. 4 figs.

  13. Fiber optic D dimer biosensor

    DOEpatents

    Glass, Robert S.; Grant, Sheila A.

    1999-01-01

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

  14. Recent Development in Optical Fiber Biosensors

    PubMed Central

    Bosch, María Espinosa; Sánchez, Antonio Jesús Ruiz; Rojas, Fuensanta Sánchez; Ojeda, Catalina Bosch

    2007-01-01

    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.

  15. Rugged fiber optic probe for raman measurement

    DOEpatents

    O'Rourke, Patrick E.; Toole, Jr., William R.; Nave, Stanley E.

    1998-01-01

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

  16. Optical fiber head for providing lateral viewing

    DOEpatents

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2004-03-01

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

  18. Emerging technology in fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Dyott, Richard B.

    1991-03-01

    Some recent innovations in interferoinetric fiber optic sensors include special fibers new components and sensor systems. Many of the concepts have precedents in microwaves. 1. GENERAL PRINCIPLES The application of optical fibers to sensors is diffuse compared with their application to optical communications which is essentially focused on the single problem of how to get information from A to B. A fiber sensor is viable when it can do something not possible with better than more cheaply than any existing method. The probability of the emergence of a new sensor depends on the length of time that a need for the sensor and the possibility of meeting that need have co-existed regardless of whether the need or the possibility has appeared first. 2. TYPES OF SENSOR Fiber sensors can be divided into: a) Multimode fiber sensors which depend on amplitude effects b) Single mode (single path) fiber sensors which depend on phase effects. Since multimode fiber has existed for many decades the emergence of a new multimode sensor depends mostly on the discovery of a new need for such a sensor. On the other hand single mode/single path (i. e. polarization maintaining) fiber is relatively new and so is still being applied to existing needs. This is particularly so of recent innovations in fibers and components. SPIE Vol. 1396 Applications of Optical Engineering Proceedings of OE/Midwest ''90 / 709

  19. Biodegradable polymer optical fiber (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhang, Chenji; Kalaba, Surge; Shan, Dingying; Xu, Kaitian; Yang, Jian; Liu, Zhiwen

    2016-10-01

    Biocompatible and even biodegradable polymers have unique advantages in various biomedical applications. Recent years, photonic devices fabricated using biocompatible polymers have been widely studied. In this work, we manufactured an optical fiber using biodegradable polymer POC and POMC. This step index optical fiber is flexible and easy to handle. Light was coupled into this polymer fiber by directly using objective. The fiber has a good light guiding property and an approximate loss of 2db/cm. Due to the two layer structure, our fiber is able to support applications inside biological tissue. Apart from remarkable optical performance, our fiber was also found capable of performing imaging. By measuring the impulse response of this multimode polymer fiber and using the linear inversion algorithm, concept proving experiments were completed. Images input into our fiber were able to be retrieved from the intensity distribution of the light at the output end. Experiment result proves the capability of our optical fiber to be used as a fiber endoscopy no needs to remove.

  20. Curved Piezoelectric Actuators for Stretching Optical Fibers

    NASA Technical Reports Server (NTRS)

    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.

  1. The design of scanning fiber optical system

    NASA Astrophysics Data System (ADS)

    Bai, Yangbo; Xiang, Wanghua; Zu, Peng; Li, Xu; Ren, Fang; Shi, Xiaozhou; Xu, Xiaoyan

    2009-11-01

    A novel scanning fiber optical system for multi-channel optical switch has been demonstrated. This scanning fiber system consists of motor, photoelectric encoder, EPOS position controller, Field Programmable Gate Array (FPGA), fiber laser, transmitting energy fiber bundle, reflector, five-dimensional optical adjustable mounts, etc. In this device, the control system is composed of EPOS position controller and FPGA. Furthermore, the photoelectric encoder is directly connected to the central shaft of the motor to read its position information. The reflector is slantways fixed on the other end of the motor central shaft. Also, the fiber bundle is fixed by optical adjustable mounts to achieve slight position adjustment, which is used as launching system of this configuration. In the operation process, the motor in uniform rotation state drives the photoelectric encoder and the reflector at the same angle velocity. The photoelectric encoder reads the incremental signal and absolute position signal of motor, and then sends them to EPOS position controller and FPGA respectively. FPGA sends square wave signal to the fiber laser under the control of EPOS position controller and FPGA. Triggered by the square wave signal, the fiber laser emits a laser pulse to the center point of the reflector. At the same time, the reflector makes the laser pulse transmitting into a certain transmitting energy fiber according to the angle of the reflector at that moment. Therefore, with the motor rotates at uniform speed, the laser pulse is sent to different fibers, by which multi-channel optical switch is completed.

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

    PubMed

    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.

  3. Polarized Spatial Soliton in a Chiral Optical Fiber

    DTIC Science & Technology

    2000-09-29

    Torres-Silva and M. Zamorano Departamento de Electr6nica, Facultad de Ingenieria , Univesidad de Tarapacd Casilla 6 D, Av. 18 de Septiembre 2222, Arica...plasma surface wave," Advances in Complex Electromagnetic Materials. Kruwer Academic Publishers, 38, Netherlands, 249, 1997. M. Agrawal, Nonlinear Fiber Optics. Academic: New York, 1995. Mexicana de Fisica , 46(l),62, 2000.

  4. Advanced Optical Fiber Communications Systems

    DTIC Science & Technology

    1994-08-31

    oscillator saser 0 !4Iiga B f Figure 1-2. Block diagram of the homodyne AM-WIRNA link. 1.3.2 System EvaluationI Table 1-1 contains the definitions of the...1.6). However, as a result of the spectral broadening due to the phase noise, the selection of the IF bandwidth is critical to the system...node’s intermediate frequency (IF) using a portion of the transmitter light for the laser LO. The desired channel (in this case, node 1) is then selected

  5. Nanoimprint of a 3D structure on an optical fiber for light wavefront manipulation.

    PubMed

    Calafiore, Giuseppe; Koshelev, Alexander; Allen, Frances I; Dhuey, Scott; Sassolini, Simone; Wong, Edward; Lum, Paul; Munechika, Keiko; Cabrini, Stefano

    2016-09-16

    Integration of complex photonic structures onto optical fiber facets enables powerful platforms with unprecedented optical functionalities. Conventional nanofabrication technologies, however, do not permit viable integration of complex photonic devices onto optical fibers owing to their low throughput and high cost. In this paper we report the fabrication of a three-dimensional structure achieved by direct nanoimprint lithography on the facet of an optical fiber. Nanoimprint processes and tools were specifically developed to enable a high lithographic accuracy and coaxial alignment of the optical device with respect to the fiber core. To demonstrate the capability of this new approach, a 3D beam splitter has been designed, imprinted and optically characterized. Scanning electron microscopy and optical measurements confirmed the good lithographic capabilities of the proposed approach as well as the desired optical performance of the imprinted structure. The inexpensive solution presented here should enable advancements in areas such as integrated optics and sensing, achieving enhanced portability and versatility of fiber optic components.

  6. Nanoimprint of a 3D structure on an optical fiber for light wavefront manipulation

    NASA Astrophysics Data System (ADS)

    Calafiore, Giuseppe; Koshelev, Alexander; Allen, Frances I.; Dhuey, Scott; Sassolini, Simone; Wong, Edward; Lum, Paul; Munechika, Keiko; Cabrini, Stefano

    2016-09-01

    Integration of complex photonic structures onto optical fiber facets enables powerful platforms with unprecedented optical functionalities. Conventional nanofabrication technologies, however, do not permit viable integration of complex photonic devices onto optical fibers owing to their low throughput and high cost. In this paper we report the fabrication of a three-dimensional structure achieved by direct nanoimprint lithography on the facet of an optical fiber. Nanoimprint processes and tools were specifically developed to enable a high lithographic accuracy and coaxial alignment of the optical device with respect to the fiber core. To demonstrate the capability of this new approach, a 3D beam splitter has been designed, imprinted and optically characterized. Scanning electron microscopy and optical measurements confirmed the good lithographic capabilities of the proposed approach as well as the desired optical performance of the imprinted structure. The inexpensive solution presented here should enable advancements in areas such as integrated optics and sensing, achieving enhanced portability and versatility of fiber optic components.

  7. Thermal strain analysis of optic fiber sensors.

    PubMed

    Her, Shiuh-Chuan; Huang, Chih-Ying

    2013-01-31

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

  8. Microbend fiber-optic temperature sensor

    DOEpatents

    Weiss, Jonathan D.

    1995-01-01

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

  9. Structural diagnostics using optical fiber sensors

    NASA Astrophysics Data System (ADS)

    Surace, Giuseppe; Chiaradia, Agostino

    1997-11-01

    After establishing the basis for assessing the structural implications of introducing a widespread sensor architecture in laminated composite materials in order to precisely identify and locate damage, the paper addresses the problem of structural diagnostics with a discussion of the development of several optical sensors. The research project will first investigate a passive optical fiber impact sensor to be implemented in the matrix of a composite material used in aeronautic and automotive applications. The senor's operating principle is based on the changes in propagation conditions occurring in a fiber subjected to transverse compression: under these circumstances, structural microdistortions produce local energy losses and hence a reduction in the optical power which propagates in the fiber and can be measured at its opposite end. As optical power losses also take place as a result of micro-bending of the optical fiber's longitudinal axis, a preliminary feasibility study will measure power attenuation versus fiber curve radius as the first step in the development of an optical fiber delamination sensor which locates separations between the layers of a composite material, i.e. debonding of sandwich panel core faces. Finally, an active impact sensor will be developed which uses optical fiber's sensitivity to pressure changes to detect the pressure gradient caused by an approaching vehicle or obstacle. The automotive industry will be able to make strategic use of these sensors, for example by installing them on vehicle sides to active the side airbag in the event of impact or collision.

  10. Novel optical fibers for data center applications

    NASA Astrophysics Data System (ADS)

    Li, Ming-Jun

    2016-02-01

    We discuss new optical fibers for high data rate short reach systems in data center applications. We review first recent development in MMF to improve system performance including high bandwidth MMF, bend insensitive MMF and MMF optimized for high bandwidth at longer wavelengths of 1060 nm or 1310 nm. Then we present a new universal fiber that can be used for both multimode transmission at 850 nm and single mode transmission at 1310 nm for data centers. Finally, we present a promising solution for high density parallel optical data links by using space division multiplexing (SDM) over multicore fibers and few mode fibers.

  11. Method for producing angled optical fiber tips in the laboratory

    NASA Astrophysics Data System (ADS)

    Davenport, John J.; Hickey, Michelle; Phillips, Justin P.; Kyriacou, Panicos A.

    2016-02-01

    A simple laboratory method is presented for producing optical fibers with tips polished at various angles. Angled optical fiber tips are used in applications such as optical sensing and remote laser surgery, where they can be used to control the angle of light leaving the fiber or direct it to the side. This allows for greater control and allows areas to be reached that otherwise could not. Optical fibers were produced with tip angles of 45 deg using a Perspex mounting block with an aluminum base plate. The dispersion of light leaving the tip was tested using a blue (470 nm) LED. The angle imposed an angular shift on the light diffracting out of the tip of approximately 30 deg. Additionally, some light reflected from the tip surface to diffract at 90 deg through the side of the fiber. These observations are consistent with theory and those seen by other studies, validating the method. The method was simple to perform and does not require advanced manufacturing tools. The method is suitable for producing small quantities of angle-tipped optical fibers for research applications.

  12. Investigation of Optical Fibers for Nonlinear Optics.

    DTIC Science & Technology

    1985-11-01

    organic photoresists. From 1961 to 1968 he was employed at Korad, working on improving the Verneuil method of crystal growth and also on the development of...1 CCrystallFibers .................... 11C.BORAHE Crystal Fiber Growth ..................... 433. BOGR~p~x~ OF E~y ERSOL...matching value with temperature for 7052 glass fiber embedded in an ADP crystal ......................... 44 9 Horizontal traveling-zone fiber growth

  13. Investigation of Optical Fibers for Nonlinear Optics.

    DTIC Science & Technology

    1983-02-01

    growth was attempted in a Bridgman apparatus and showed limited success, produc- ing encapsulated fibers roughly 2 cm long. The poten- tial of...Method for SC Fiber Growth .................................. 4 C. Vapor-Stabilized Bridgman Method for SC Fibers ....... ..................... 8 D. Melt...7 4 Differential thermal analysis curve for encapsulated KDP ..... .......................... . 9 5 Stabilized Bridgman growth apparatus

  14. Optical fiber cable chemical stripping fixture

    NASA Technical Reports Server (NTRS)

    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.

  15. Fiber optic links for antenna remoting

    NASA Astrophysics Data System (ADS)

    Glomb, Walter L., Jr.

    1992-12-01

    A high linearity, high dynamic range analog fiber optic link is described which allows high fidelity distortion-free communications transmission from 2 to 500 MHz and provides an alternative to conventional coaxial cables used to remote RF receivers from their antennas. All signals within four frequency bands (2-30, 30-90, 90-180, and 180-500 MHz) and within specified voltage ranges are detected and transmitted via fiber optics. This function is performed by a system of four separate analog fiber-optic links, one for each of the four bands. The discussion covers the electro-optic, mechanical, and thermal design of the fiber optic link, the performance model, reliability analysis, and performance tests.

  16. Optical design of a high power fiber optic coupler

    SciTech Connect

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

    1991-06-19

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

  17. Improved mesostructure by incorporating surfactant on thin film to develop an advanced optical fiber pH sensor with a temperature cross sensitivity feature

    NASA Astrophysics Data System (ADS)

    Dhara, Papiya; Singh, Vinod Kumar

    2017-03-01

    A new optical fiber pH sensor based on bromothymol blue (BTB) thin film with temperature cross-sensitivity has been proposed in this paper. The BTB thin film was prepared by depositing a thin layer of a solution containing tetraethyl orthosilicate (TEOS) and a BTB pH indicator in the presence of surfactants, namely cetyltrimethyl ammonium bromide (C19H42BrN, CTAB), by sol–gel technology on an unclad multimode fiber (MMF) surface. The number of layers and the deposition length of the thin film were varied, and the power transmission versus pH variation was studied. The concentration of the surfactant was increased to understand the effect of increasing porosity in the sol–gel matrix to achieve improved pH sensitivity. A straightforward way to utilize the temperature cross-sensitivity feature of the optical fiber pH-sensitive device has been introduced to develop a high sensitivity temperature sensor. A sensitivity of 79.96 nW pH‑1 was obtained by a 20-layer thin-film coated sensor in the pH range of 3–12.

  18. Stimulated thermal Rayleigh scattering in optical fibers.

    PubMed

    Dong, Liang

    2013-02-11

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

  19. Microbend fiber-optic chemical sensor

    DOEpatents

    Weiss, Jonathan D.

    2002-01-01

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

  20. Optical Fiber Sensors for the Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Mignani, A. G.; Falciai, R.; Trono, C.

    Two examples of optical fiber sensors for the protection of the cultural heritage were given. The varnished optical fiber could be used also as temperature sensor. In fact, thanks to the good temperature sensitivity and reversibility of gum mastic, it could be considered as a transducer for the implementation of a temperature sensor to be permanently inlayed in the painting. By embedding the optical fiber in the painting together with the picture varnish for example on a comer, continuous temperature monitoring could be possible, in order to prevent risk conditions that can arise when illuminating the painting with the use of lamps, as happens during television shots.

  1. Intelsat and fiber optics - Challenge and opportunity

    NASA Astrophysics Data System (ADS)

    Hampton, John D.

    Fiber optic technology is both a challenge and an opportunity for Intelsat in developing competitive strategies. Intelsat compares favorably with fiber-optic undersea cables in terms of cost and capacity and can serve a greater variety of service and network requirements. Domestic fiber optic local and long distance networks present opportunities for Intelsat to expand access to its network. Intelsat also has a broad-based strategy designed to: (1) capitalize on Intelsat's strengths; (2) use existing and planned resources more efficiently and in new and innovative ways; (3) introduce new operational and planning initiatives; and (4) emphasize digital service capability and ISDN compatibility.

  2. Characterization of Fiber Optic CMM Probe System

    SciTech Connect

    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.

  3. Fiber optical ranging sensor for proximity fuse

    NASA Astrophysics Data System (ADS)

    Du, Fang; Chi, Zeying; You, Mingjun; Chen, Wenjian

    1996-09-01

    A fiber optical ranging sensor used in laser proximity fuze is described in this paper. In the fuze, pulse laser diode (LD) is used as light source and trigger signal is generated by comparing the reflected light pulses with the reference pulses by a correlator after they were converted into electric signals by PIN photodiodes. Multi-mode fibers and integrated optical devices are used in the system so that the structure can be more compact. Optical fiber delay line is used to offer precise delay time for reference channel.

  4. Sequential-Impulse Generator Uses Fiber-Optics

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1982-01-01

    Light pulse from a ruby or neodymium-glass laser enters miniature optics of repetitive-detonation apparatus. Traveling along a bundle of optical fibers, light strikes laser-sensitive microdetonator and charge explodes. Apparatus then advances next charge in train into position. Possible applications of sequential-impulse generator are in creating shock waves for aerodynamics research and in generating electrical power by magnetohydrodynamics.

  5. Stabilizing Fiber-Optic Transmission Lines

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  6. Lightning vulnerability of fiber-optic cables.

    SciTech Connect

    Martinez, Leonard E.; Caldwell, Michele

    2008-06-01

    One reason to use optical fibers to transmit data is for isolation from unintended electrical energy. Using fiber optics in an application where the fiber cable/system penetrates the aperture of a grounded enclosure serves two purposes: first, it allows for control signals to be transmitted where they are required, and second, the insulating properties of the fiber system help to electrically isolate the fiber terminations on the inside of the grounded enclosure. A fundamental question is whether fiber optic cables can allow electrical energy to pass through a grounded enclosure, with a lightning strike representing an extreme but very important case. A DC test bed capable of producing voltages up to 200 kV was used to characterize electrical properties of a variety of fiber optic cable samples. Leakage current in the samples were measured with a micro-Ammeter. In addition to the leakage current measurements, samples were also tested to DC voltage breakdown. After the fiber optic cables samples were tested with DC methods, they were tested under representative lightning conditions at the Sandia Lightning Simulator (SLS). Simulated lightning currents of 30 kA and 200 kA were selected for this test series. This paper documents measurement methods and test results for DC high voltage and simulated lightning tests performed at the Sandia Lightning Simulator on fiber optic cables. The tests performed at the SLS evaluated whether electrical energy can be conducted inside or along the surface of a fiber optic cable into a grounded enclosure under representative lightning conditions.

  7. Orbital angular momentum in optical fibers

    NASA Astrophysics Data System (ADS)

    Bozinovic, Nenad

    Internet data traffic capacity is rapidly reaching limits imposed by nonlinear effects of single mode fibers currently used in optical communications. Having almost exhausted available degrees of freedom to orthogonally multiplex data in optical fibers, researchers are now exploring the possibility of using the spatial dimension of fibers, via multicore and multimode fibers, to address the forthcoming capacity crunch. While multicore fibers require complex manufacturing, conventional multi-mode fibers suffer from mode coupling, caused by random perturbations in fibers and modal (de)multiplexers. Methods that have been developed to address the problem of mode coupling so far, have been dependent on computationally intensive digital signal processing algorithms using adaptive optics feedback or complex multiple-input multiple-output algorithms. Here we study the possibility of using the orbital angular momentum (OAM), or helicity, of light, as a means of increasing capacity of future optical fiber communication links. We first introduce a class of specialty fibers designed to minimize mode coupling and show their potential for OAM mode generation in fibers using numerical analysis. We then experimentally confirm the existence of OAM states in these fibers using methods based on fiber gratings and spatial light modulators. In order to quantify the purity of created OAM states, we developed two methods based on mode-image analysis, showing purity of OAM states to be 90% after 1km in these fibers. Finally, in order to demonstrate data transmission using OAM states, we developed a 4-mode multiplexing and demultiplexing systems based on free-space optics and spatial light modulators. Using simple coherent detection methods, we successfully transmit data at 400Gbit/s using four OAM modes at a single wavelength, over 1.1 km of fiber. Furthermore, we achieve data transmission at 1.6Tbit/s using 10 wavelengths and two OAM modes. Our study indicates that OAM light can exist

  8. Power-efficient nonreciprocal interferometer and linear-scanning fiber-optic catheter for optical coherence tomography.

    PubMed

    Bouma, B E; Tearney, G J

    1999-04-15

    A nonreciprocal fiber-optic interferometer is demonstrated in an optical coherence tomography (OCT) system. The increased power efficiency of this system provides a 4.1-dB advantage over standard Michelson implementations. In addition, a new linear-scanning fiber-optic catheter is demonstrated that avoids the rotary optical junction that is required in circumferential scanning systems. These advancements have permitted the clinical implementation of OCT imaging in the human gastrointestinal tract.

  9. Fiber optic coherent laser radar 3d vision system

    SciTech Connect

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-12-31

    Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  10. Fiber-optic sensors for aerospace electrical measurements: An update

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1991-01-01

    Fiber-optic sensors are being developed for electrical current, voltage, and power measurements in aerospace applications. These sensors are presently designed to cover ac frequencies from 60 Hz to 20 kHz. The current sensor, based on the Faraday effect in optical fiber, is in advanced development after some initial testing. Concentration is on packaging methods and ways to maintain consistent sensitivity with changes in temperature. The voltage sensor, utilizing the Pockels effect in a crystal, has excelled in temperature tests. This paper reports on the development of these sensors, the results of evaluation, improvements now in progress, and the future direction of the work.

  11. Fiber optic, Faraday rotation current sensor

    SciTech Connect

    Veeser, L.R.; Day, G.W.

    1986-01-01

    At the Second Megagauss Conference in 1979, there were reports of experiments that used the Faraday magneto-optic effect in a glass rod to measure large electric current pulses or magnetic fields. Since then we have seen the development of single-mode optical fibers that can carry polarized light in a closed loop around a current load. A fiber optic Faraday rotation sensor will integrate the flux, instead of sampling it at a discrete point, to get a measurement independent of the current distribution. Early Faraday rotation experiments using optical fibers to measure currents dealt with problems such as fiber birefringence and difficulties in launching light into the tiny fiber cores. We have built on those experiments, working to reduce the effects of shocks and obtaining higher bandwidths, absolute calibration, and computerized recording and data analysis, to develop the Faraday rotation sensors into a routine current diagnostic. For large current pulses we find reduced sensitivity to electromagnetic interference and other backgrounds than for Rogowski loops; often the fiber optic sensors are useful where conductive probes cannot be used at all. In this paper we describe the fiber optic sensors and some practical matters involved in fielding them.

  12. Side-emitting fiber optic position sensor

    SciTech Connect

    Weiss, Jonathan D.

    2008-02-12

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

  13. Optical isolator system for fiber-optic uses

    NASA Technical Reports Server (NTRS)

    Lutes, George

    1988-01-01

    A low loss optical isolator suitable for fiber-optic uses has been assembled from commercial components. The isolator exhibits reverse isolation of greater than 70 dB, with a forward loss of less than 1.3dB. This system provides an effective approach for reducing instabilities encountered in the output signal of semiconductor lasers in certain applications of fiber-optic systems. The paper presents a phenomenological explanation for the superior performance of the isolator system.

  14. Optical isolator system for fiber-optic uses.

    PubMed

    Lutes, G

    1988-04-01

    A low loss optical isolator suitable for fiber-optic uses has been assembled from commercial components. The isolator exhibits reverse isolation of >70 dB, with a forward loss of <1.3 dB. This system provides an effective approach for reducing instabilities encountered in the output signal of semiconductor lasers in certain applications of fiber-optic systems. The paper presents a phenomenological explanation for the superior performance of the isolator system.

  15. Fiber optic electric field sensor technology

    NASA Technical Reports Server (NTRS)

    Jarzynski, J.; De Paula, R. P.

    1987-01-01

    The properties of piezoactive plastics are reviewed as well as the fiber-optic electric field sensors studied so far. A particular configuration consisting of a concentric piezoactive jacket on the glass fiber is discussed in detail and the frequency response of this sensor is projected over a wide range of frequencies. The present design has the practical advantages of leading to a compact lightweight sensor; longer fiber lengths may be used to increase sensitivity. It is predicted that, at low frequencies, a fiber-optic antenna using a 1-km length of fiber would be capable of detecting a minimum electric field of 43 microV/m assuming a minimum phase sensitivity of 10 to the -6th radians for the optical Mach-Zehnder interferometer.

  16. Metal-embedded optical fiber pressure sensor

    NASA Astrophysics Data System (ADS)

    Kidwell, J. J.; Berthold, John W.

    1991-02-01

    The paper reports the results of work to demonstrate the feasibility of embedding a metal-buffered optical fiber inside a thin metal diaphragm to create a pressure-sensitive transducer. A method was developed to embed butt-coupled optical fibers inside brass diaphragms. Butt-coupled fibers with two different end spacings were successfully embedded in the diaphragms. The pressure response of the diaphragms was calibrated by measuring the changes in light transmission through the butt coupling as a function of pressure. In addition to embedded fiber pressure sensors, this method may be useful for other applications. The calibration results indicate the method could be used to make connections between signal processors and optical fibers embedded in composites.

  17. Robust incoherent fiber optic bundle decoder

    NASA Technical Reports Server (NTRS)

    Roberts, Hilary E. (Inventor); DePlachett, Charles P. (Inventor); Deason, Brent E. (Inventor); Pilgrim, Robert A. (Inventor); Sanford, Harold S. (Inventor)

    2003-01-01

    Apparatus and method for calibrating an incoherent fiber optic bundle for use in transmitting visual or infrared coherent images. The apparatus includes a computer, a computer video monitor, an objective lens adjacent to the input end of the bundle, a second lens adjacent the output end of the bundle, and a CCD camera. The camera transmits video data to the monitor to produce an illuminated fiber optic image. The coordinates for the center of each fiber is found through an imaging process and the output fibers coordinates are related to the input fiber coordinates and processed in the computer to produce a mapping lookup-table (LUT) unique to the specific fiber bundle. Remapping of the LUT due to changes in the lens focus, CCD camera, or the addition of an infrared filter is accomplished by a software utility in the computer.

  18. Compact fiber optic immunosensor using tapered fibers and acoustic enhancement

    NASA Astrophysics Data System (ADS)

    Zhou, Chonghua; Pivarnik, Philip E.; Auger, Steven; Rand, Arthur G.; Letcher, Stephen V.

    1997-06-01

    A compact fiber-optic sensing system that features all-fiber optical design and semiconductor-laser excitation has been developed and tested. A 2X2 fiber coupler directs the input light to the SMA connected sensing fiber tip and the fluorescent signal back to a CCD fiber spectrophotometer. In this system, the fluorescent signal is confined in the fiber system so the signal-to-noise ratio is greatly improved and the system can be operate in ambient light conditions. The utilization of a red laser diode has reduced the background signal of non-essential biomolecules. The fluorescent dye used is Cy5, which has an excitation wavelength of 650 nm and a fluorescent center wavelength of 680 nm. To illustrate the biosensor's diagnostic capabilities, a sandwich immunoassay to detect Salmonella is presented. Tapered fiber tips with different shapes and treatments were studied and optimized. An enhancement system employing ultrasonic concentration of target particles has also been developed and applied to the detection of Salmonella. The immunoassay was conducted in a test chamber that also serves as an ultrasonic standing-wave cell and allows microspheres to be concentrated in a column along the fiber probe. The system demonstrates broad promise in future biomedical application.

  19. Theoretical Analysis Of A Sagnac Fiber Optic Interferometer

    NASA Astrophysics Data System (ADS)

    Szustakowski, Mieczyslaw; Jaroszewicz, Leszek R.

    1990-04-01

    The analytical description of a closed optical fiber interferometer system based on Jones calculus is presented. This calculus adapation for the optical fiber elements analysis allows for a uniform description of system built on the basis of a single-mode optical fiber. The analysis of a Sagnac fiber optic interferometer is an example of this method application.

  20. Electromagnetic enviromental effects on shipboard fiber optic installations

    NASA Astrophysics Data System (ADS)

    Bucholz, Roger C.

    1991-02-01

    The inherent immunity of fiber optic materials to electromagnetic environmental effects provides numerous opportunities for wide-spread use of fiber optics aboard ship. Federal budget constraints may reduce the development of new fiber optic systems to address military applications. However there are sufficient similarities between industrial and military sensor needs to warrant use of off-the-shelf fiber optic sensor systems.

  1. Gap soliton propagation in optical fiber gratings

    NASA Astrophysics Data System (ADS)

    Mohideen, U.; Slusher, R. E.; Mizrahi, V.; Erdogan, T.; Kuwata-Gonokami, M.; Lemaire, P. J.; Sipe, J. E.; Martijn de Sterke, C.; Broderick, Neil G. R.

    1995-08-01

    Intense optical pulse propagation in a GeO2 -doped silica glass fiber grating results in nonlinear pulse propagation velocities and increased transmission at wavelengths where the grating reflects light in the linear limit. These nonlinear pulse propagation effects are predicted by numerical simulations of gap soliton propagation. The large linear refractive-index variations used for the fiber gratings in these experiments permit the propagation of gap solitons in short lengths of fiber.

  2. Spaceborne Fiber Optic Data Bus (SFODB)

    NASA Technical Reports Server (NTRS)

    Bretthauer, Joy W.; Chalfant, Chuck H.; Orlando, Fred J.; Rezek, Ed; Sawyer, Marc

    1998-01-01

    The SFODB is a standardized, gigabit per second, highly reliable, fault tolerant fiber optic network. SFODB was designed to the harsh space environments and real-time, on-board data handling applications of high speed, remote sensing spacecraft.

  3. Multipurpose fiber-optic access network

    NASA Astrophysics Data System (ADS)

    Han, Kwan H.; Kim, Hoon; Chung, Yun C.

    2002-10-01

    We propose and demonstrate a multipurpose fiber-optic access network (MFAN). This network uses the same fiber infrastructure for a variety of services including baseband, cable television (CATV), personal communication service (PCS), wireless local loop (WLL), and local multipoint communication service (LMCS). The experimental results show that the proposed network could support the independent operation of these services.

  4. Fiber Optic Communications Technology. A Status Report.

    ERIC Educational Resources Information Center

    Hull, Joseph A.

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

  5. Optical Fibers Would Sense Local Temperatures

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio O.; Rogowski, Robert S.

    1994-01-01

    Proposed fiber-optic transducers measure local temperatures. Includes lead-in and lead-out lengths producing no changes in phase shifts, plus short sensing length in which phase shift sensitive to temperature. Phase shifts in two-mode fibers vary with temperatures.

  6. Design and performance of a fiber optic gyroscope using integrated optics

    NASA Technical Reports Server (NTRS)

    Youmans, B. R.; Bartman, R. K.; Salomon, P. M.; Minford, W. J.; Stone, F. T.

    1990-01-01

    Navigation grade fiber optic rotation sensors (FORS) are being developed as an alternative to spinning mass gyro's for unmanned planetary exploration spacecraft. FORS is attractive because of its many advantages such as long life, low weight, low power, and low cost as compared to its mechanical counterparts. FORS incorporates an advanced integrated optics circuit. The advanced eight-component integrated optics circuit performs all the key signal processing functions and in addition incorporates a unique optical beat detection circuit thereby providing an output in the form of pulses proportional to incremental angular position similar to a ring laser gyro (RLG) but without the inherent lock-in problem RLG's possess.

  7. Advanced experiments with an erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Marques, Paulo V. S.; Marques, Manuel B.; Rosa, Carla C.

    2014-07-01

    This communication describes an optical hands-on fiber laser experiment aimed at advanced college courses. Optical amplifiers and laser sources represent very important optical devices in numerous applications ranging from telecommunications to medicine. The study of advanced photonics experiments is particularly relevant at undergraduate and master level. This paper discusses the implementation of an optical fiber laser made with a cavity built with two tunable Bragg gratings. This scheme allows the students to understand the laser working principles as a function of the laser cavity set-up. One or both of the gratings can be finely tuned in wavelength through applied stress; therefore, the degree of spectral mismatch of the two gratings can be adjusted, effectively changing the cavity feedback. The impact of the cavity conditions on the laser threshold, spectrum and efficiency is analyzed. This experiment assumes that in a previous practice, the students should had already characterized the erbium doped fiber in terms of absorption and fluorescent spectra, and the spectral gain as a function of pump power.

  8. Fiber optics welder having movable aligning mirror

    DOEpatents

    Higgins, Robert W.; Robichaud, Roger E.

    1981-01-01

    A system for welding fiber optic waveguides together. The ends of the two fibers to be joined together are accurately, collinearly aligned in a vertical orientation and subjected to a controlled, diffuse arc to effect welding and thermal conditioning. A front-surfaced mirror mounted at a 45.degree. angle to the optical axis of a stereomicroscope mounted for viewing the junction of the ends provides two orthogonal views of the interface during the alignment operation.

  9. Fiber optic detector for immuno-testing

    DOEpatents

    Partin, Judy K.; Ward, Thomas E.; Grey, Alan E.

    1992-01-01

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

  10. Fiber Optic Tactical Local Network (FOTLAN)

    NASA Technical Reports Server (NTRS)

    Bergman, L. A.; Hartmayer, R.; Wu, W. H.; Cassell, P.; Edgar, G.; Lambert, J.; Mancini, R.; Jeng, J.; Pardo, C.

    1991-01-01

    A 100 Mbit/s FDDI (fiber distributed data interface) network interface unit is described that supports real-time data, voice and video. Its high-speed interrupt-driven hardware architecture efficiently manages stream and packet data transfer to the FDDI network. Other enhancements include modular single-mode laser-diode fiber optic links to maximize node spacing, optic bypass switches for increased fault tolerance, and a hardware performance monitor to gather real-time network diagnostics.

  11. Fresnel drag effect in fiber optic gyroscope

    NASA Technical Reports Server (NTRS)

    Vali, V.; Berg, M. F.; Shorthill, R. W.

    1978-01-01

    Consideration is given to the development of a low-noise fiber-optic ring interferometer gyroscope. A technique for measuring the Fresnel drag coefficient of optical fibers is described, and the accuracy of the technique is considered. An experiment is performed which allows verification of the Einstein velocity addition theorem to the first nonlinear term. An experimental setup for measuring Fresnel drag is described: it consists of a Sagnac interferometer and a Fresnel drag measurement configuration.

  12. Research for Electronic Fiber Optics Technologists

    NASA Technical Reports Server (NTRS)

    Lawrence, Ellis E.

    1999-01-01

    The intent of this project was to provide research experiences for socially and economically disadvantaged students in networking via fiber optics. The objectives of this project were: 1) To provide knowledge and skills needed by students to use the tools and equipment essential to networking NASA's and the university's topologies; 2) To provide the student researchers with needed mathematical skills and concepts to progress in fiber optic technology; 3) To afford the principal investigator an opportunity to become certified in fiber optics; 4) To build a transmitter and receiver circuit that will be linked by fiber-optic cable to demonstrate mastery of concepts; and 5) To conduct research for NASA and the University in the fiber-optic system. The research will attempt to develop applications for THUNDER (Thin-layer Composite Unimorph Ferroelectric Driver and Sensor) and LARC-SI (Langley Research Center- Soluble Polyimide), (inventions at NASA/LaRC) and fiber-optic technology that will be beneficial to NASA, the university and the consumer. This research has the potential of improving the nation's manpower in the area of fiberoptic technology. It will allow students the opportunity to participate in visible research at NASA and in industry.

  13. Optical fiber sensor technique for strain measurement

    DOEpatents

    Butler, Michael A.; Ginley, David S.

    1989-01-01

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

  14. Advances in drilling with fiber lasers

    NASA Astrophysics Data System (ADS)

    Naeem, Mohammed

    2015-07-01

    High brightness quasi- continuous wave (QCW) and continuous wave (CW) fiber lasers are routinely being used for cutting and welding for a range of industrial applications. However, to date very little work has been carried out or has been reported on laser drilling with these laser sources. This work describes laser drilling ((trepan and percussion) of nickel based superalloys (thermal barrier coated and uncoated) with a high power QCW fiber laser. This presentation will highlight some of the most significant aspect of laser drilling, i.e. SmartPierceTM, deep hole drilling and small hole drilling. These advances in processing also demonstrate the potential for fiber laser processing when an advanced interface between laser and an open architecture controller are used.

  15. Optical-Fiber Fluorosensors With Polarized Light Sources

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio O.; Rogowski, Robert S.

    1995-01-01

    Chemiluminescent and/or fluorescent molecules in optical-fiber fluorosensors oriented with light-emitting dipoles along transverse axis. Sensor of proposed type captures greater fraction of chemiluminescence or fluorescence and transmits it to photodetector. Transverse polarization increases sensitivity. Basic principles of optical-fiber fluorosensors described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525), "Improved Optical-Fiber Chemical Sensors" (LAR-14607), and "Improved Optical-Fiber Temperature Sensors" (LAR-14647).

  16. Advanced specialty fiber designs for high power fiber lasers

    NASA Astrophysics Data System (ADS)

    Gu, Guancheng

    The output power of fiber lasers has increased rapidly over the last decade. There are two major limiting factors, namely nonlinear effects and transverse mode instability, prohibiting the power scaling capability of fiber lasers. The nonlinear effects, originating from high optical intensity, primarily limit the peak power scaling. The mode instability, on the other hand, arises from quantum-defect driven heating, causing undesired mode coupling once the power exceeds the threshold and degradation of beam quality. The mode instability has now become the bottleneck for average output power scaling of fiber lasers. Mode area scaling is the most effective way to mitigate nonlinear effects. However, the use of large mode area may increase the tendency to support multiple modes in the core, resulting in lower mode instability threshold. Therefore, it is critical to maintain single mode operation in a large mode area fiber. Sufficient higher order mode suppression can lead to effective single-transverse-mode propagation. In this dissertation, we explore the feasibility of using specialty fiber to construct high power fiber lasers with robust single-mode output. The first type of fiber discussed is the resonantly-enhanced leakage channel fiber. Coherent reflection at the fiber outer boundary can lead to additional confinement especially for highly leaky HOM, leading to lower HOM losses than what are predicted by conventional finite element mothod mode solver considering infinite cladding. In this work, we conducted careful measurements of HOM losses in two leakage channel fibers (LCF) with circular and rounded hexagonal boundary shapes respectively. Impact on HOM losses from coiling, fiber boundary shapes and coating indexes were studied in comparison to simulations. This work demonstrates the limit of the simulation method commonly used in the large-mode-area fiber designs and the need for an improved approach. More importantly, this work also demonstrates that a

  17. Fiber optic wide region temperature sensing system

    NASA Astrophysics Data System (ADS)

    Xu, Xunjian; Nonaka, Koji; Song, Hongbin

    2008-12-01

    A fiber optic wide region temperature sensing system based on optical pulse correlation measurement and SHG differential detection technique is proposed and demonstrated. In order to establish the reliability of this fiber optic temperature sensing system, a long-term wide region outside temperature monitoring experiment with a new designed 20ps time-bias optical pulse correlation unit for wide measurement rang was carried out. The temperature measured by means of a correlation sensor had the same variation as and higher sensitivity and quick measurement response than the digital thermometer. The resolution of the correlation sensor is approximately +/-0.01 oC . This fiber optic temperature sensor can measure even in very tough environment and low and high temperature range. Not only point temperature but also a field area average temperature can monitor by this system.

  18. Investigation of Microstructured Optical Fiber in Eight Fiber Laser

    NASA Astrophysics Data System (ADS)

    Bahloul, Faouzi; Ennejah, Tarek; Attia, Rabah

    2012-06-01

    In passively mode locked fiber laser, case of 8FL (Eight Fiber Laser), the management of length, linear and non linear parameters of the cavity plays a paramount role in the generation of stable ultra short pulses with high peak powers. In this work, we propose an 8FL consisted of MOF (Microstructured Optical Fiber). According to the various properties of the MOF, we studied the variation of the pulses peak power and width. We demonstrated that there are optimal parameters of the MOF for which the peak power is maximal and the width is minimal.

  19. Investigation of Microstructured Optical Fiber in Eight Fiber Laser

    NASA Astrophysics Data System (ADS)

    Bahloul, Faouzi; Ennejah, Tarek; Attia, Rabah

    2011-09-01

    In passively mode locked fiber laser, case of 8FL (Eight Fiber Laser), the management of length, linear and non linear parameters of the cavity plays a paramount role in the generation of stable ultra short pulses with high peak powers. In this work, we propose an 8FL consisted of MOF (Microstructured Optical Fiber). According to the various properties of the MOF, we studied the variation of the pulses peak power and width. We demonstrated that there are optimal parameters of the MOF for which the peak power is maximal and the width is minimal.

  20. Benefits of glass fibers in solar fiber optic lighting systems.

    PubMed

    Volotinen, Tarja T; Lingfors, David H S

    2013-09-20

    The transmission properties and coupling of solar light have been studied for glass core multimode fibers in order to verify their benefits for a solar fiber optic lighting system. The light transportation distance can be extended from 20 m with plastic fibers to over 100 m with the kind of glass fibers studied here. A high luminous flux, full visible spectrum, as well as an outstanding color rendering index (98) and correlated color temperature similar to the direct sun light outside have been obtained. Thus the outstanding quality of solar light transmitted through these fibers would improve the visibility of all kinds of objects compared to fluorescent and other artificial lighting. Annual relative lighting energy savings of 36% in Uppsala, Sweden, and 76% in Dubai were estimated in an office environment. The absolute savings can be doubled by using glass optical fibers, and are estimated to be in the order of 550 kWh/year in Sweden and 1160 kWh/year in Dubai for one system of only 0.159 m(2) total light collecting area. The savings are dependent on the fiber length, the daily usage time of the interior, the type of artificial lighting substituted, the system light output flux, and the available time of sunny weather at the geographic location.

  1. Construction of an Optical Fiber Strain Gauge

    NASA Astrophysics Data System (ADS)

    Sulaiman, Najwa

    This project is focused on the construction of an optical fiber strain gauge that is based on a strain gauge described by Butter and Hocker. Our gauge is designed to generate an interference pattern from the signals carried on two bare single-mode fibers that are fastened to an aluminum cantilever. When the cantilever experiences flexural stress, the interference pattern should change. By observing this change, it is possible to determine the strain experienced by the cantilever. I describe the design and construction of our optical fiber strain gauge as well as the characterization of different parts of the apparatus.

  2. Mobile fiber-optic laser Doppler anemometer.

    PubMed

    Stieglmeier, M; Tropea, C

    1992-07-20

    A laser Doppler anemometer (LDA) has been developed that combines the compactness and low power consumption of laser diodes and avalanche photodiodes with the flexibility and possibility of miniaturization by using fiber-optic probes. The system has been named DFLDA for laser diode fiber LDA and is especially suited for mobile applications, for example, in trains, airplanes, or automobiles. Optimization considerations of fiber-optic probes are put forward and several probe examples are described in detail. Measurement results from three typical applications are given to illustrate the use of the DFLDA. Finally, a number of future configurations of the DFLDA concept are discussed.

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

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

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

    PubMed

    Yang, Xinghua; Liu, Yanxin; Tian, Fengjun; Yuan, Libo; Liu, Zhihai; Luo, Shenzi; Zhao, Enming

    2012-06-01

    A fiber optic integrated modulation-depth-tunable modulator based on a type of hollow optical fiber with suspended core is proposed and investigated. We synthesized magnetic fluid containing superparamagnetic Fe(3)O(4) nanoparticles and encapsulated it in the hollow optical fiber as the cladding layer of the suspended core by fusing the hollow optical fiber with the multimode optical fibers. The light with a wavelength of 632.8 nm is coupled in and out of the modulating element by a tapering technique. Experimental results show that the light attenuation in the system can be greatly influenced by only 2.0×10(-2) μL of the magnetic fluid under different magnetic field strengths. The saturated modulation depth is 43% when the magnetic field strength is 489 Oe. The response time of the system is <120 ms. Significantly, this work presents information for the development of all-fiber modulators, including other integrated electro-optic devices, such as optical switch, optical fiber filter, and magnetic sensors utilizing the special structure of this hollow optical fiber with suspended core and superparamagnetic magnetic fluid.

  5. Flow sensor using optical fiber strain gauges

    NASA Astrophysics Data System (ADS)

    Schmitt, Nicolas F.; Morgan, R.; Scully, Patricia J.; Lewis, Elfed; Chandy, Rekha

    1995-09-01

    A novel technique for the measurement of air flow velocity using an optical fiber sensor is reported. The sensor measures the deformation of a rubber cantilever beam when subjected to the stresses induced by drag forces in the presence of the airflow. Tests performed in a wind tunnel have indicated a sensitivity of 2 (mu) /(m/s). A qualitative model based on fiber mode propagation has been developed which allows the sensor to be characterized in terms of optical losses. A single 1 mm diameter polymer fiber is mounted on the rectangular section rubber cantilever (section 14 mm by 6 mm) and six grooves are etched into the fiber which extend into the core of the fiber. As the beam deviates the surface deforms (stretches or contracts) and the fiber is subjected to strain. As the strain is increased the grooves become wider and the amount of light transmitted through the fiber is reduced due to increased losses. The sensor described has all the advantages of optical fiber sensors including electrical noise immunity and intrinsic safety for use in hazardous environments. However, its simple construction, robustness, versatility for a number of different fluid applications, as well as relatively low cost make it attractive for use in a wide variety of measurement applications e.g. wind velocity measurement where airborne moisture or chemicals are present.

  6. Compensated vibrating optical fiber pressure measuring device

    DOEpatents

    Fasching, George E.; Goff, David R.

    1987-01-01

    A microbending optical fiber is attached under tension to a diaphragm to se a differential pressure applied across the diaphragm which it causes it to deflect. The fiber is attached to the diaphragm so that one portion of the fiber, attached to a central portion of the diaphragm, undergoes a change in tension; proportional to the differential pressure applied to the diaphragm while a second portion attached at the periphery of the diaphragm remains at a reference tension. Both portions of the fiber are caused to vibrate at their natural frequencies. Light transmitted through the fiber is attenuated by both portions of the tensioned sections of the fiber by an amount which increases with the curvature of fiber bending so that the light signal is modulated by both portions of the fiber at separate frequencies. The modulated light signal is transduced into a electrical signal. The separate modulation signals are detected to generate separate signals having frequencies corresponding to the reference and measuring vibrating sections of the continuous fiber, respectively. A signal proportional to the difference between these signals is generated which is indicative of the measured pressure differential across the diaphragm. The reference portion of the fiber is used to compensate the pressure signal for zero and span changes resulting from ambient temperature and humidity effects upon the fiber and the transducer fixture.

  7. Nanosecond laser damage of optical multimode fibers

    NASA Astrophysics Data System (ADS)

    Mann, Guido; Krüger, Jörg

    2016-07-01

    For pulse laser materials processing often optical step index and gradient index multimode fibers with core diameters ranging from 100 to 600 μm are used. The design of a high power fiber transmission system must take into account limitations resulting from both surface and volume damage effects. Especially, breakdown at the fiber end faces and selffocusing in the fiber volume critically influence the fiber performance. At least operation charts are desirable to select the appropriate fiber type for given laser parameters. In industry-relevant studies the influence of fiber core diameter and end face preparation on laser-induced (surface) damage thresholds (LIDT) was investigated for frequently used all-silica fiber types (manufacturer LEONI). Experiments on preform material (initial fiber material) and compact specimens (models of the cladding and coating material) accompanied the tests performed in accordance with the relevant LIDT standards ISO 21254-1 and ISO 21254-2 for 1-on-1 and S-on-1 irradiation conditions, respectively. The relation beam diameter vs. LIDT was investigated for fused silica fibers. Additionally, laser-induced (bulk) damage thresholds of fused silica preform material F300 (manufacturer Heraeus) in dependence on external mechanical stress simulating fiber bending were measured. All experiments were performed with 10-ns laser pulses at 1064 and 532 nm wavelength with a Gaussian beam profile.

  8. Fourier transform optical profilometry using fiber optic Lloyd's mirrors.

    PubMed

    Kart, Türkay; Kösoğlu, Gülşen; Yüksel, Heba; İnci, Mehmet Naci

    2014-12-10

    A fiber optic Lloyd's mirror assembly is used to obtain various optical interference patterns for the detection of 3D rigid body shapes. Two types of fiber optic Lloyd's systems are used in this work. The first consists of a single-mode optical fiber and a highly reflecting flat mirror to produce bright and dark strips. The second is constructed by locating a single-mode optical fiber in a v-groove, which is formed by two orthogonal flat mirrors to allow the generation of square-type interference patterns for the desired applications. The structured light patterns formed by these two fiber Lloyd's techniques are projected onto 3D objects. Fringe patterns are deformed due to the object's surface topography, which are captured by a digital CCD camera and processed with a Fourier transform technique to accomplish 3D surface topography of the object. It is demonstrated that the fiber-optic Lloyd's technique proposed in this work is more compact, more stable, and easier to configure than other existing surface profilometry systems, since it does not include any high-cost optical tools such as aligners, couplers, or 3D stages. The fringe patterns are observed to be more robust against environmental disturbances such as ambient temperature and vibrations.

  9. Fiber optic plantar pressure/shear sensor

    NASA Astrophysics Data System (ADS)

    Soetanto, William; Nguyen, Ngoc T.; Wang, Wei-Chih

    2011-04-01

    A full-scale foot pressure/shear sensor that has been developed to help diagnose the cause of ulcer formation in diabetic patients is presented. The design involves a tactile sensor array using intersecting optical fibers embedded in soft elastomer. The basic configuration incorporates a mesh that is comprised of two sets of parallel optical fiber plane; the planes are configured so the parallel rows of fiber of the top and bottom planes are perpendicular to each other. Threedimensional information is determined by measuring the loss of light from each of the waveguide to map the overall pressure distribution and the shifting of the layers relative to each other. In this paper we will present the latest development on the fiber optic plantar pressure/shear sensor which can measure normal force up from 19.09 kPa to 1000 kPa.

  10. Miniature fiber optic surface plasmon resonance biosensors

    NASA Astrophysics Data System (ADS)

    Slavik, Radan; Brynda, Eduard; Homola, Jiri; Ctyroky, Jiri

    1999-01-01

    A novel design of surface plasmon resonance fiber optic sensor is reported which leads to a compact, highly miniaturized sensing element with excellent sensitivity. The sensing device is based on a side-polished single-mode optical fiber with a thin metal overlayer supporting surface plasmon waves. The strength of interaction between a fiber mode and a surface plasmon wave depends strongly on the refractive index near the sensing surface. Therefore, refractive index changes associated with biospecific interaction between antibodies immobilized on the sensor and antigen molecules can be monitored by measuring light intensity variations. Detection of horse radish peroxidase (HRP) of the concentration of 100 ng/ml has been accomplished using the fiber optic sensor with a matrix of monoclonal antibodies against HRP immobilized on the sensor surface.

  11. Submicron diameter single crystal sapphire optical fiber

    DOE PAGES

    Hill, Cary; Homa, Daniel; Liu, Bo; ...

    2014-10-02

    In this work, a submicron-diameter single crystal sapphire optical fiber was demonstrated via wet acid etching at elevated temperatures. Etch rates on the order 2.3 µm/hr were achievable with a 3:1 molar ratio sulfuric-phosphoric acid solution maintained at a temperature of 343°C. A sapphire fiber with an approximate diameter of 800 nm was successfully fabricated from a commercially available fiber with an original diameter of 50 µm. The simple and controllable etching technique provides a feasible approach to the fabrication of unique waveguide structures via traditional silica masking techniques. The ability to tailor the geometry of sapphire optical fibers ismore » the first step in achieving optical and sensing performance on par with its fused silica counterpart.« less

  12. Submicron diameter single crystal sapphire optical fiber

    SciTech Connect

    Hill, Cary; Homa, Daniel; Liu, Bo; Yu, Zhihao; Wang, Anbo; Pickrell, Gary

    2014-10-02

    In this work, a submicron-diameter single crystal sapphire optical fiber was demonstrated via wet acid etching at elevated temperatures. Etch rates on the order 2.3 µm/hr were achievable with a 3:1 molar ratio sulfuric-phosphoric acid solution maintained at a temperature of 343°C. A sapphire fiber with an approximate diameter of 800 nm was successfully fabricated from a commercially available fiber with an original diameter of 50 µm. The simple and controllable etching technique provides a feasible approach to the fabrication of unique waveguide structures via traditional silica masking techniques. The ability to tailor the geometry of sapphire optical fibers is the first step in achieving optical and sensing performance on par with its fused silica counterpart.

  13. Advanced optics in an interdisciplinary graduate program

    NASA Astrophysics Data System (ADS)

    Nic Chormaic, S.

    2014-07-01

    The Okinawa Institute of Science and Technology Graduate University, established in November 2011, provides a 5- year interdisciplinary PhD program, through English, within Japan. International and Japanese students entering the program undertake coursework and laboratory rotations across a range of topics, including neuroscience, molecular science, physics, chemistry, marine science and mathematics, regardless of previous educational background. To facilitate interdisciplinarity, the university has no departments, ensuring seamless interactions between researchers from all sectors. As part of the PhD program a course in Advanced Optics has been developed to provide PhD students with the practical and theoretical skills to enable them to use optics tools in any research environment. The theoretical aspect of the course introduces students to procedures for complex beam generation (e.g. Laguerre-Gaussian), optical trapping, beam analysis and photon optics, and is supported through a practical program covering introductory interference/diffraction experiments through to more applied fiber optics. It is hoped that, through early exposure to optics handling and measurement techniques, students will be able to develop and utilize optics tools regardless of research field. In addition to the formal course in Advanced Optics, a selection of students also undertakes 13 week laboratory rotations in the Light-Matter Interactions research laboratory, where they work side-by-side with physicists in developing optics tools for laser cooling, photonics or bio-applications. While currently in the first year, conclusive results about the success of such an interdisciplinary PhD training are speculative. However, initial observations indicate a rich cross-fertilization of ideas stemming from the diverse backgrounds of all participants.

  14. Fiber optics wavelength division multiplexing(components)

    NASA Technical Reports Server (NTRS)

    Hendricks, Herbert D.

    1985-01-01

    The long term objectives are to develop optical multiplexers/demultiplexers, different wavelength and modulation stable semiconductor lasers and high data rate transceivers, as well as to test and evaluate fiber optic networks applicable to the Space Station. Progress in each of the above areas is briefly discussed.

  15. Multiplexed fiber-optic transmission system

    NASA Technical Reports Server (NTRS)

    Bell, C. H.

    1977-01-01

    Digital, audio, and video data channels spanning 100 megahertz bandwidth are transmitted via single fiber-optical link. System is flexible by virtue of its plug-in modularity and optical patchboard that allows it to adjust to data and bandwidth changes.

  16. In Situ Fiber-Optic Reflectance Monitor

    NASA Technical Reports Server (NTRS)

    Linton, Roger C.; Gray, Perry A.

    1996-01-01

    In situ fiber-optic reflectance monitor serves as simple means of monitoring changes in reflectance of specimen exposed to simulated outerspace or other environments in vacuum chamber. Eliminates need to remove specimen from vacuum chamber, eliminating optical changes and bleaching such removal causes in coatings.

  17. Advanced optical fuzing technology

    NASA Astrophysics Data System (ADS)

    von der Lippe, Christian M.; Liu, J. Jiang

    2005-09-01

    We are developing a robust and compact photonic proximity sensor for munition applications. Successful implementation of this sensor will provide a new capability for direct fire applications. The photonic component development exploits pioneering work and unique expertise at ARDEC, ARL, and Sandia National Laboratories by combining key optoelectronic technologies to design and demonstrate components for this fuzing application. The technologies employed in the optical fuze design are vertical cavity surface-emitting lasers (VCSELs), the p-i-n or metal-semiconductor-metal (MSM) photodetectors, and miniature lenses optics. This work will culminate in a robust, fully integrated, g-hardened component design suitable for proximity fuzing applications. This compact sensor will replace costly assemblies that are based on discrete lasers, photodetectors, and bulk optics. It will be mass manufacturable and impart huge savings for such applications. The specific application under investigation is for gun-fired munitions. Nevertheless, numerous civilian uses exist for this proximity sensor in automotive, robotics and aerospace applications. This technology is also applicable to robotic ladar and short-range 3-D imaging.

  18. Optical Fiber Communications Cable Connector.

    DTIC Science & Technology

    1981-07-01

    incorp- oration of the TRW Cinch Optalign 4 double elbow " fiber alignment guide concept. Means for connecting either Siecor or ITT six fiber cable were...the guide, and forced toward the top cusp by the double elbow con- figuration. The geometry of the guide is such that normal tolerances of molded or

  19. NITINOL Interconnect Device for Optical Fiber Waveguides

    DTIC Science & Technology

    1981-07-01

    LE EL,~NAVSEA REPORT NO. S27L~kV-NL 4P fNSWNC TR 81-129 1 JULY 1981 0 NITINOL INTERC&INECT DEVICE FOR OPTICAL FIBER WAVEGUIDES FINAL REPORT A...ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER NSWC TR 81-129I 1-19 -A )ci , ’ 4 TI TL E (and Sbtitle) S. TYPE OF REPORT & PERIOD COVERED NITINOL ... NITINOL Optical Fibers 20. ABSTRACT (Continue on reverse side if neceeewy and identify by block number) Two different interconnect devices for optical

  20. Multimode fiber optic wavelength division multiplexing

    NASA Technical Reports Server (NTRS)

    Spencer, J. L.

    1982-01-01

    Optical wavelength division multiplexing (WDM) systems, with signals transmitted on different wavelengths through a single optical fiber, can have increased bandwidth and fault isolation properties over single wavelength optical systems. Two WDM system designs that might be used with multimode fibers are considered and a general description of the components which could be used to implement the system are given. The components described are sources, multiplexers, demultiplexers, and detectors. Emphasis is given to the demultiplexer technique which is the major developmental component in the WDM system.

  1. Fiber optic phase stepping system for interferometry

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1991-01-01

    A closed loop phase control system using an all-fiber optical configuration has been developed for use in phase-stepping interferometry. This system drives the relative phase of two interfering beams through a sequence of pi/2 rad increments so that the initial relative phase of these beams can be determined. This phase-stepping system uses optical fibers to provide spatially uniform phase steps from a flexible, easily aligned optical configuration. In addition, this system uses phase feedback to eliminate phase modulator errors and to compensate for phase drifts caused by environmental disturbances.

  2. Optical fiber sensors for life support applications

    NASA Astrophysics Data System (ADS)

    Lieberman, R. A.; Schmidlin, E. M.; Ferrell, D. J.; Syracuse, S. J.

    1992-07-01

    Preliminary experimental results on systems designed to demonstrate sensor operation in regenerative food production and crew air supply applications are presented. The systems use conventional fibers and sources in conjunction with custom wavelength division multiplexers in their optical signal processing sections and nonstandard porous optical fibers in the optical sensing elements. It is considered to be possible to create practical sensors for life-support system applications, and particularly, in regenerative food production environments, based on based on reversible sensors for oxygen, carbon monoxide, and humidity.

  3. Optical fiber sensors for life support applications

    NASA Technical Reports Server (NTRS)

    Lieberman, R. A.; Schmidlin, E. M.; Ferrell, D. J.; Syracuse, S. J.

    1992-01-01

    Preliminary experimental results on systems designed to demonstrate sensor operation in regenerative food production and crew air supply applications are presented. The systems use conventional fibers and sources in conjunction with custom wavelength division multiplexers in their optical signal processing sections and nonstandard porous optical fibers in the optical sensing elements. It is considered to be possible to create practical sensors for life-support system applications, and particularly, in regenerative food production environments, based on based on reversible sensors for oxygen, carbon monoxide, and humidity.

  4. Design of fiber optic adaline neural networks

    NASA Astrophysics Data System (ADS)

    Ghosh, Anjan K.; Trepka, Jim

    1997-03-01

    Based on possible optoelectronic realization of adaptive filters and equalizers using fiber optic tapped delay lines and spatial light modulators we describe the design of a single-layer fiber optic Adaline neural network that can be used as a bit pattern classifier. In our design, we employ as few electronic devices as possible and use optical computation to utilize the advantages of optics in processing speed, parallelism, and interconnection. The described new optical neural network design is for optical processing of guided light wave signals, not electronic signals. We analyze the convergence or learning characteristics of the optoelectronic Adaline in the presence of errors in the hardware. We show that with such an optoelectronic Adaline it is possible to detect a desired code word/token/header with good accuracy.

  5. Fiber-optic interconnection networks for spacecraft

    NASA Technical Reports Server (NTRS)

    Powers, Robert S.

    1992-01-01

    The overall goal of this effort was to perform the detailed design, development, and construction of a prototype 8x8 all-optical fiber optic crossbar switch using low power liquid crystal shutters capable of operation in a network with suitable fiber optic transmitters and receivers at a data rate of 1 Gb/s. During the earlier Phase 1 feasibility study, it was determined that the all-optical crossbar system had significant advantages compared to electronic crossbars in terms of power consumption, weight, size, and reliability. The result is primarily due to the fact that no optical transmitters and receivers are required for electro-optic conversion within the crossbar switch itself.

  6. Optical fiber Raman amplifier and distributed fiber Raman sensors

    NASA Astrophysics Data System (ADS)

    Zhang, Zaixuan; Jin, Shangzhong; Liu, Honglin; Kim, Insoo S.; Wang, Jianfeng; Wu, Xiaobiao; Guo, Ning; Liu, Tao; Yu, Xiangdong

    2003-06-01

    The backscattering spectrum of optical fiber has been measured by use 1427 nm Raman laser and Q8384 optical spectrum analyzer and Stokes and anti-Stokes ZX band backscattering spectrum has been first observed and discussed, ZX band frequency shift is 1THz, bandwidth 3THz(3dB). Optimum design of S-band negative dispersion DCF discrete fiber Raman amplifier has been researched by OPTIAMP DESIGN 3.3 SOFTWARE (made in Canada Optiwave Corporation) and gain spectrum and gain vs. power of DCF discrete fiber Raman amplifier have been measured, practical including Stokes ZX band backscattering gain effect. Pump on/off small signal gain is 13dB (pump power 700mw; fiber 5.1km) and gain band width is 88nm (1440nm-1528nm). The operation principle, configuration and performance of distributed fiber Raman temperature sensors system has been researched. Amplification of anti-Stokes spontaneity Raman scattering (ARS) effect of fiber and its temperature effect has been first observed and discussed. It has been applied to 30km distributed FRS system.

  7. [INVITED] New advances in polymer fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Nogueira, Rogério; Oliveira, Ricardo; Bilro, Lúcia; Heidarialamdarloo, Jamshid

    2016-04-01

    During the last years, fiber Bragg gratings (FBGs) written in polymer optical fibers (POFs) have been pointed as an interesting alternative to silica FBGs for applications in sensors and in optical access networks. In order to use such components in real applications, the manipulation of POFs, as well as the increase of quality in the production of FBGs has to be achieved. In this article some of the recent advances regarding these two aspects are reported and include recent developments to produce smooth POFs end face with high quality, benefiting the current splicing process and the inscription of high quality FBGs in a few seconds. Furthermore, additional characterizations to strain, temperature, pressure, and humidity are also shown.

  8. Fiber optic strain measurement for machine monitoring

    NASA Astrophysics Data System (ADS)

    Hoffmann, L.; Mueller, M. S.; Koch, A. W.

    2007-06-01

    Monitoring machines during operation is an important issue in measurement engineering. The usual approach to monitoring specific machine components is using strain gauges. Strain gauges, however, may sometimes not be used if conditions are harsh or installation space is limited. Fiber optic sensors seem to be an alternative here, but dynamic health monitoring has been dificult so far. The focus of this field study is to measure vibration characteristics of machine parts during operation using fiber optic sensors with the objective of early damage detection. If that was possible, downtime and maintenance costs could be minimized. Therefore a field test for dynamic fiber optic strain measurement on a roller bearing was carried out. The test setup consisted of the bearing built into a gear test stand and equipped with an array of fiber Bragg grating sensors. Fifteen fiber sensors were interrogated with a sample rate of 1 kHz and the vibration pattern was extracted. The radial load distribution was measured with high spatial resolution and a high degree of compliance with simulation data was found. The findings suggest that fiber optic health monitoring for machine components is feasible and reasonable. Especially with the help of distributed sensing on various components extensive health monitoring on complex technical systems is possible.

  9. Optical and electrical characterizations of multifunctional silver phosphate glass and polymer-based optical fibers.

    PubMed

    Rioux, Maxime; Ledemi, Yannick; Morency, Steeve; de Lima Filho, Elton Soares; Messaddeq, Younès

    2017-03-03

    In recent years, the fabrication of multifunctional fibers has expanded for multiple applications that require the transmission of both light and electricity. Fibers featuring these two properties are usually composed either of a single material that supports the different characteristics or of a combination of different materials. In this work, we fabricated (i) novel single-core step-index optical fibers made of electrically conductive AgI-AgPO3-WO3 glass and (ii) novel multimaterial fibers with different designs made of AgI-AgPO3-WO3 glass and optically transparent polycarbonate and poly (methyl methacrylate) polymers. The multifunctional fibers produced show light transmission over a wide range of wavelengths from 500 to 1000 nm for the single-core fibers and from 400 to 1000 nm for the multimaterial fibers. Furthermore, these fibers showed excellent electrical conductivity with values ranging between 10(-3) and 10(-1) S·cm(-1) at room temperature within the range of AC frequencies from 1 Hz to 1 MHz. Multimodal taper-tipped fibre microprobes were then fabricated and were characterized. This advanced design could provide promising tools for in vivo electrophysiological experiments that require light delivery through an optical core in addition to neuronal activity recording.

  10. Optical and electrical characterizations of multifunctional silver phosphate glass and polymer-based optical fibers

    NASA Astrophysics Data System (ADS)

    Rioux, Maxime; Ledemi, Yannick; Morency, Steeve; de Lima Filho, Elton Soares; Messaddeq, Younès

    2017-03-01

    In recent years, the fabrication of multifunctional fibers has expanded for multiple applications that require the transmission of both light and electricity. Fibers featuring these two properties are usually composed either of a single material that supports the different characteristics or of a combination of different materials. In this work, we fabricated (i) novel single-core step-index optical fibers made of electrically conductive AgI-AgPO3-WO3 glass and (ii) novel multimaterial fibers with different designs made of AgI-AgPO3-WO3 glass and optically transparent polycarbonate and poly (methyl methacrylate) polymers. The multifunctional fibers produced show light transmission over a wide range of wavelengths from 500 to 1000 nm for the single-core fibers and from 400 to 1000 nm for the multimaterial fibers. Furthermore, these fibers showed excellent electrical conductivity with values ranging between 10‑3 and 10‑1 S·cm‑1 at room temperature within the range of AC frequencies from 1 Hz to 1 MHz. Multimodal taper-tipped fibre microprobes were then fabricated and were characterized. This advanced design could provide promising tools for in vivo electrophysiological experiments that require light delivery through an optical core in addition to neuronal activity recording.

  11. Optical and electrical characterizations of multifunctional silver phosphate glass and polymer-based optical fibers

    PubMed Central

    Rioux, Maxime; Ledemi, Yannick; Morency, Steeve; de Lima Filho, Elton Soares; Messaddeq, Younès

    2017-01-01

    In recent years, the fabrication of multifunctional fibers has expanded for multiple applications that require the transmission of both light and electricity. Fibers featuring these two properties are usually composed either of a single material that supports the different characteristics or of a combination of different materials. In this work, we fabricated (i) novel single-core step-index optical fibers made of electrically conductive AgI-AgPO3-WO3 glass and (ii) novel multimaterial fibers with different designs made of AgI-AgPO3-WO3 glass and optically transparent polycarbonate and poly (methyl methacrylate) polymers. The multifunctional fibers produced show light transmission over a wide range of wavelengths from 500 to 1000 nm for the single-core fibers and from 400 to 1000 nm for the multimaterial fibers. Furthermore, these fibers showed excellent electrical conductivity with values ranging between 10−3 and 10−1 S·cm−1 at room temperature within the range of AC frequencies from 1 Hz to 1 MHz. Multimodal taper-tipped fibre microprobes were then fabricated and were characterized. This advanced design could provide promising tools for in vivo electrophysiological experiments that require light delivery through an optical core in addition to neuronal activity recording. PMID:28256608

  12. Compact parallel optical interface built with optical fiber tips

    NASA Astrophysics Data System (ADS)

    Kopp, Christophe; Gilbert, Karen; Bernabe, Stéphane; Albert, Blandine

    2006-09-01

    MultiChip Module approach and the use of micro-optics offer determinant solutions to reach the mechanical compactness required by most applications for high rate data communications transmitters and receivers. Such a miniaturization often leads to develop very challenging assembling processes when fiber coupling is needed. In this paper we present an original fabrication process to build very small parallel optical interface with optical fiber tips. This fabrication process is based on common fiber ribbon mounting into wet etched V shaped holder into silicon and a dicing-polishing step to create small pieces with optical quality considering flatness and roughness. The dicing-polishing principle is well-known in integrated waveguides technology. An example of realization is presented to connect a parallel optical subassembly transmitter with a MPO/MTP connector. The results show that the dicing-polishing step allows to obtain a diced-polished face with a roughness about 5 to 10nm onto the fiber. Such an optical quality is as good as a cleaved fiber when measuring light coupling performances. Thus, such micro-optical components offer a new building block for designers to extract the light from their photonic devices. Moreover, the fabrication process appears to be low cost and compatible with mass production.

  13. Fiber optic sensors for structural health monitoring of air platforms.

    PubMed

    Guo, Honglei; Xiao, Gaozhi; Mrad, Nezih; Yao, Jianping

    2011-01-01

    Aircraft operators are faced with increasing requirements to extend the service life of air platforms beyond their designed life cycles, resulting in heavy maintenance and inspection burdens as well as economic pressure. Structural health monitoring (SHM) based on advanced sensor technology is potentially a cost-effective approach to meet operational requirements, and to reduce maintenance costs. Fiber optic sensor technology is being developed to provide existing and future aircrafts with SHM capability due to its unique superior characteristics. This review paper covers the aerospace SHM requirements and an overview of the fiber optic sensor technologies. In particular, fiber Bragg grating (FBG) sensor technology is evaluated as the most promising tool for load monitoring and damage detection, the two critical SHM aspects of air platforms. At last, recommendations on the implementation and integration of FBG sensors into an SHM system are provided.

  14. Fiber Optic Sensors for Structural Health Monitoring of Air Platforms

    PubMed Central

    Guo, Honglei; Xiao, Gaozhi; Mrad, Nezih; Yao, Jianping

    2011-01-01

    Aircraft operators are faced with increasing requirements to extend the service life of air platforms beyond their designed life cycles, resulting in heavy maintenance and inspection burdens as well as economic pressure. Structural health monitoring (SHM) based on advanced sensor technology is potentially a cost-effective approach to meet operational requirements, and to reduce maintenance costs. Fiber optic sensor technology is being developed to provide existing and future aircrafts with SHM capability due to its unique superior characteristics. This review paper covers the aerospace SHM requirements and an overview of the fiber optic sensor technologies. In particular, fiber Bragg grating (FBG) sensor technology is evaluated as the most promising tool for load monitoring and damage detection, the two critical SHM aspects of air platforms. At last, recommendations on the implementation and integration of FBG sensors into an SHM system are provided. PMID:22163816

  15. Exploiting surface plasmon scattering on optical fibers

    NASA Astrophysics Data System (ADS)

    Klantsataya, Elizaveta; François, Alexandre; Sciacca, Beniamino; Zuber, Agnieszka; Ebendorff-Heidepriem, Heike; Hoffmann, Peter; Monro, Tanya M.

    2016-12-01

    For decades Surface Plasmon Resonance (SPR) has been one of the corner stones of label free biosensing with a wide range of architectures including optical fiber based SPR. Traditionally, the resonance is monitored through reflectivity measurements at a single wavelength as a function of the incident angle in a standard Kretschmann configuration, or transmission of broadband light through an optical fiber. In both cases, SPR is inferred through optical losses. An alternative approach is to use SPR scattering induced by rough metallic coatings, enabling to turn an intrinsically nonradiative process into a radiative one. As a result, the SPR signal corresponding to the resonance can be seen as light at specific wavelengths being re-emitted by the rough metallic coating. Here, we present results we have achieved using SPR scattering as an alternative approach for optical fiber based plasmonic sensors. Although the use of a rough metallic coating induces some inherent limitations, such as a lower resolution, the architectural advantages and simplicity of the approach offer additional opportunities, such as multiplexing and self-referencing, which are not possible otherwise with a single fiber SPR sensor. A way to overcome the lower resolution that involves the use of microstructured optical fibers, as well as a new perspective on a complementary application, such as Metal Enhanced Fluorescence, which greatly benefits from SPR scattering, will be presented.

  16. Single optical fiber probe for optogenetics

    NASA Astrophysics Data System (ADS)

    Falk, Ryan; Habibi, Mohammad; Pashaie, Ramin

    2012-03-01

    With the advent of optogenetics, all optical control and visualization of the activity of specific cell types is possible. We have developed a fiber optic based probe to control/visualize neuronal activity deep in the brain of awake behaving animals. In this design a thin multimode optical fiber serves as the head of the probe to be inserted into the brain. This fiber is used to deliver excitation/stimulation optical pulses and guide a sample of the emission signal back to a detector. The major trade off in the design of such a system is to decrease the size of the fiber and intensity of input light to minimize physical damage and to avoid photobleaching/phototoxicity but to keep the S/N reasonably high. Here the excitation light, and the associated emission signal, are frequency modulated. Then the output of the detector is passed through a time-lens which compresses the distributed energy of the emission signal and maximizes the instantaneous S/N. By measuring the statistics of the noise, the structure of the time lens can be designed to achieve the global optimum of S/N. Theoretically, the temporal resolution of the system is only limited by the time lens diffraction limit. By adding a second detector, we eliminated the effect of input light fluctuations, imperfection of the optical filters, and back-reflection of the excitation light. We have also designed fibers and micro mechanical assemblies for distributed delivery and detection of light.

  17. Safely splicing glass optical fibers

    NASA Technical Reports Server (NTRS)

    Korbelak, K.

    1980-01-01

    Field-repair technique fuses glass fibers in flammable environment. Apparatus consists of v-groove vacuum chucks on manipulators, high-voltage dc power supply and tungsten electrodes, microscope to observe joint alignment and fusion, means of test transmission through joint. Apparatus is enclosed in gas tight bos filled with inert gas during fusion. About 2 feet of fiber end are necessary for splicing.

  18. Research and Development on Ultra-Lightweight Low-Loss Optical Fiber Communication Cable.

    DTIC Science & Technology

    FIBER OPTICS TRANSMISSION LINES, LIGHTWEIGHT), GLASS , FIBERS , ORGANIC COATINGS, POLYURETHANE RESINS, SOLUTIONS(GENERAL), POWDERS, ELECTROSTATICS...EXTRUSION, RUGGEDIZED EQUIPMENT, BROADBAND, OPTICAL COMMUNICATIONS, TACTICAL COMMUNICATIONS, FIBER OPTICS, LOSSES.

  19. Fiber laser coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-03-04

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

  20. Fiber coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan

    2008-08-12

    A spark delivery system for generating a spark using a laser beam is provided, the spark delivery system including a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. In addition, the laser delivery assembly includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. In accordance with embodiments of the present invention, the assembly may be used to create a spark in a combustion engine. In accordance with other embodiments of the present invention, a method of using the spark delivery system is provided. In addition, a method of choosing an appropriate fiber for creating a spark using a laser beam is also presented.

  1. Towards high-quality optical ceramic YAG fibers for high-energy laser (HEL) applications

    NASA Astrophysics Data System (ADS)

    Lee, HeeDong; Keller, Kristin; Sirn, Brian

    2012-06-01

    There is a critical demand for high quality, transparent ceramic YAG fibers for high powered fiber lasers. The production of laser quality ceramic fibers hinges on advanced ceramic processing technology, along with the availability of highly sinterable powder with high phase and chemical purity. These two fundamental technologies have been successfully developed at UES. Nd (1.1 a/o) and Yb (1.0 a/o)-doped yttrium aluminum garnet (YAG) fibers with high optical quality were produced by combining UES's tailored powders with advanced consolidation processes including fiber extrusion and vacuum sintering. The as-sintered and as-annealed fibers, approximately 30 microns in diameter, appeared transparent and successfully transmitted laser beams; further development will allow for the production of doped ceramic YAG fiber lasers for advanced high power and high energy fiber laser systems.

  2. Advanced fiber/matrix material systems

    NASA Technical Reports Server (NTRS)

    Hartness, J. Timothy

    1991-01-01

    Work completed in Phase 1 of the NASA Advanced Composite Technology program is discussed. Two towpreg forms (commingled yarns and fused powder towpregs) are being characterized under the program. These towpregs will be used to evaluate textile fabrication technologies for advanced aircraft composite structures. The unique characteristic of both of these material forms is that both fiber and matrix resin are handled in a single operation such as weaving, braiding, or fiber placement. The evaluation of both commingled and fused powder towpreg is described. Various polymer materials are considered for both subsonic and supersonic applications. Polymers initially being evaluated include thermoplastic polyimides such as Larc-TPI and New-TPI, thermoplastics such as PEEK and PEKEKK as well as some toughened crosslinked polyimides. Preliminary mechanical properties as well as tow handling are evaluated.

  3. Fiber optic sensors IV; Proceedings of the Third European Congress on Optics, The Hague, Netherlands, Mar. 13, 14, 1990

    NASA Technical Reports Server (NTRS)

    Kersten, Ralf T. (Editor)

    1990-01-01

    Recent advances in fiber-optic sensor (FOS) technology are examined in reviews and reports. Sections are devoted to components for FOSs, special fibers for FOSs, interferometry, FOS applications, and sensing principles and influence. Particular attention is given to solder glass sealing technology for FOS packaging, the design of optical-fiber current sensors, pressure and temperature effects on beat length in highly birefringent optical fibers, a pressure FOS based on vibrating-quartz-crystal technology, remote sensing of flammable gases using a fluoride-fiber evanescent probe, a displacement sensor with electronically scanned white-light interferometer, the use of multimode laser diodes in low-coherence coupled-cavity interferometry, electronic speckle interferometry compensated for environmentally induced phase noise, a dual-resolution noncontact vibration and displacement sensor based on a two-wavelength source, and fiber optics in composite materials.

  4. Multimode-Optical-Fiber Imaging Probe

    NASA Technical Reports Server (NTRS)

    Jackson, Deborah

    1999-01-01

    Currently, endoscopic surgery uses single-mode fiber-bundles to obtain in vivo image information inside the orifices of the body. This limits their use to the larger natural orifices and to surgical procedures where there is plenty of room for manipulation. The knee joint, for example, can be easily viewed with a fiber optic viewer, but joints in the finger cannot. However, there are a host of smaller orifices where fiber endoscopy would play an important role if a cost effective fiber probe were developed with small enough dimensions (less than or equal to 250 microns). Examples of beneficiaries of micro-endoscopes are the treatment of the Eustatian tube of the middle ear, the breast ducts, tear ducts, coronary arteries, fallopian tubes, as well as the treatment of salivary duct parotid disease, and the neuro endoscopy of the ventricles and spinal canal. This work describes an approach for recovering images from tightly confined spaces using multimode. The concept draws upon earlier works that concentrated on image recovery after two-way transmission through a multimode fiber as well as work that demonstrated the recovery of images after one-way transmission through a multimode fiber. Both relied on generating a phase conjugated wavefront, which was predistorted with the characteristics of the fiber. The approach described here also relies on generating a phase conjugated wavefront, but utilizes two fibers to capture the image at some intermediate point (accessible by the fibers, but which is otherwise visually inaccessible).

  5. Liquid-filled hollow core microstructured polymer optical fiber.

    PubMed

    Cox, F M; Argyros, A; Large, M C J

    2006-05-01

    Guidance in a liquid core is possible with microstructured optical fibers, opening up many possibilities for chemical and biochemical fiber-optic sensing. In this work we demonstrate how the bandgaps of a hollow core microstructured polymer optical fiber scale with the refractive index of liquid introduced into the holes of the microstructure. Such a fiber is then filled with an aqueous solution of (-)-fructose, and the resulting optical rotation measured. Hence, we show that hollow core microstructured polymer optical fibers can be used for sensing, whilst also fabricating a chiral optical fiber based on material chirality, which has many applications in its own right.

  6. Evaluations of fiber optic sensors for interior applications

    SciTech Connect

    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.

  7. Compensated Fiber-Optic Frequency Distribution Equipment

    DTIC Science & Technology

    2010-11-01

    availability of long- haul components at 1550 nm. If installing a new system with new fiber, it may also make sense to use dispersion-shifted fiber, which...selected the 1550 nm (C-Band) for the optical wavelength. Although this wavelength requires CD correction in long haul systems, it makes good sense for...CD, we place both lasers on the same ITU channel, and adjust their center wavelengths to within a few GHz of each other. Ideally, the two signals

  8. Fiber optically isolated and remotely stabilized data transmission system

    DOEpatents

    Nelson, M.A.

    1992-11-10

    A fiber optically isolated and remotely stabilized data transmission systems described wherein optical data may be transmitted over an optical data fiber from a remote source which includes a data transmitter and a power supply at the remote source. The transmitter may be remotely calibrated and stabilized via an optical control fiber, and the power source may be remotely cycled between duty and standby modes via an optical control fiber. 3 figs.

  9. Alternative Controller for a Fiber-Optic Switch

    NASA Technical Reports Server (NTRS)

    Peters, Robert

    2007-01-01

    A simplified diagram of a relatively inexpensive controller for a DiCon VX (or equivalent) fiber-optic switch -- an electromechanically actuated switch for optically connecting one or two input optical fibers to any of a number of output optical fibers is shown. DiCon VX fiber-optic switches are used primarily in research and development in the telecommunication industry. This controller can control any such switch having up to 32 output channels.

  10. Fiber optically isolated and remotely stabilized data transmission system

    DOEpatents

    Nelson, Melvin A.

    1992-01-01

    A fiber optically isolated and remotely stabilized data transmission system s described wherein optical data may be transmitted over an optical data fiber from a remote source which includes a data transmitter and a power supply at the remote source. The transmitter may be remotely calibrated and stabilized via an optical control fiber, and the power source may be remotely cycled between duty and standby modes via an optical control fiber.

  11. Status of the Fiber Optic Control System Integration (FOCSI) program

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert J.

    1993-01-01

    This report presents a discussion of the progress made in the NASA/NAVY Fiber Optic Control System Integration (FOCSI) program. This program will culminate in open-loop flight tests of passive optical sensors and associated electro-optics on an F-18 aircraft. Currently, the program is in the final stages of hardware fabrication and environmental testing of the passive optical sensors and electro-optics. This program is a foundation for future Fly-by-Light (FBL) programs. The term Fly-by-Light is used to describe the utilization of passive optical sensors and fiber optic data links for monitoring and control of aircraft in which sensor and actuation signals are transmitted optically. The benefits of this technology for advanced aircraft include the following: improved reliability and reduced certification cost due to greater immunity to EME (electromagnetic effects); reduced harness volume and weight; elimination of short circuits and sparking in wiring due to insulation deterioration; lower maintenance costs (fewer components); greater flexibility in data bus protocol and architecture; absence of ground loops; and higher operating temperatures for electrically passive optical sensors.

  12. High-NA HPCS optical fibers for medical diagnosis and treatment

    NASA Astrophysics Data System (ADS)

    Skutnik, Bolesh J.

    2010-02-01

    Hard Plastic Clad Silica (HPCS) optical fibers with pure silica cores have been developed which are robust and have NA(Numerical Aperture)>0.50. Improved clad only HPCS fibers have been produced for both new 'standard' and 'high' NA versions. Based on new cladding formulations, the 'standard' NA fiber has an NA of 0.41, while the new ultrahigh NA fiber has an NA of 0.54. Mechanical strength and preliminary fatigue data are presented along with spectral characterization data. For the first time significant results were obtained for clad only high NA fibers, The fibers are useful for diagnostic and surgical applications. Short to medium length time to failure results, indicate that the static fatigue parameters of the new high numerical aperture (NA) optical fibers are at least as good as those for former standard NA (0.37) HPCS fibers, which is an advance from previous results on the older formulation high NA fibers.

  13. Hot Springs-Garrison Fiber Optic Project

    SciTech Connect

    Not Available

    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.

  14. Quantum cryptography over underground optical fibers

    SciTech Connect

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

    1996-05-01

    Quantum cryptography is an emerging technology in which two parties may simultaneously generated shared, secret cryptographic key material using the transmission of quantum states of light whose security is based on the inviolability of the laws of quantum mechanics. An adversary can neither successfully tap the key transmissions, nor evade detection, owing to Heisenberg`s uncertainty principle. In this paper the authors describe the theory of quantum cryptography, and the most recent results from their experimental system with which they are generating key material over 14-km of underground optical fiber. These results show that optical-fiber based quantum cryptography could allow secure, real-time key generation over ``open`` multi-km node-to-node optical fiber communications links between secure ``islands.``

  15. Immunoassay procedures for fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Ligler, Frances S.

    1988-04-01

    There is an increasing need for the development of an ultrasensitive immunoassay for use with fiber optic sensors. These detection systems can be used for such applications as disease diagnosis, detection of chemical and biological warfare agents or drugs of abuse, pollution control, therapeutic monitoring, and explosive detection. This specific program is designed to produce generic chemistries for use with existing fiber optic-based sensors to detect pathogens of particular threat to Army personnel as determined by USAMRIID. The detection system under development involves the attachment of antibodies to an optical fiber at high density. In addition, the immobilization must be achieved in a way which retains the antibody's ability to bind antigen. The functionality of the antibody will be tested through the binding of a labelled antigen. In the future, this assay could incorporate the antibodies developed by the Army for pathogens of particularly military concern.

  16. Optically tunable chirped fiber Bragg grating.

    PubMed

    Li, Zhen; Chen, Zhe; Hsiao, V K S; Tang, Jie-Yuan; Zhao, Fuli; Jiang, Shao-Ji

    2012-05-07

    This work presents an optically tunable chirped fiber Bragg grating (CFBG). The CFBG is obtained by a side-polished fiber Bragg grating (SPFBG) whose thickness of the residual cladding layer in the polished area (D(RC)) varies with position along the length of the grating, which is coated with a photoresponsive liquid crystal (LC) overlay. The reflection spectrum of the CFBG is tuned by refractive index (RI) modulation, which comes from the phase transition of the overlaid photoresponsive LC under ultraviolet (UV) light irradiation. The broadening in the reflection spectrum and corresponding shift in the central wavelength are observed with UV light irradiation density of 0.64mW/mm. During the phase transition of the photoresponsive LC, the RI increase of the overlaid LC leads to the change of the CFBG reflection spectrum and the change is reversible and repeatable. The optically tunable CFBGs have potential use in optical DWDM system and an all-fiber telecommunication system.

  17. Fiber optic sensing of cyanides in solutions

    SciTech Connect

    Park, S.S.; Mackenzie, J.D.; Li, C.Y.; Guerreiro, P.; Peyghambarian, N.

    1996-12-31

    A novel sol-gel technique was used to immobilize malachite green ions (MG{sup +}) in stable, optically transparent, porous silica gel films. A simple and sensitive method was developed for the detection of cyanides in solutions using spectrophotometry to measure changes caused by cyanide ions (CN{sup {minus}}) in the absorption spectra of the green-colored silica gel films. After reaction with cyanide ions, the absorption spectra of the films changed with a typical decrease in absorbance at 620 nm. On the basis of the absorption spectra of the films, a portable and easy to use fiber optic cyanide film sensor was fabricated. Decolorization undergone by the green-colored gel films, as they were exposed to cyanide ions, was detected through a fiber. Preliminary results indicate concentrations on the order of a few ppm are detected using the fiber optic sensor.

  18. Reference frequency transmission over optical fiber

    NASA Technical Reports Server (NTRS)

    Lutes, G.; Kirk, A.

    1986-01-01

    A 100-MHz reference frequency from a hydrogen maser frequency standard has been transmitted via optical fiber over a 14-km distance with a measured stability of 1.5 X 10 to the-15 power for 1000 seconds averaging time. This capability was demonstrated in a frequency distribution experiment performed in April, 1986. The reference frequency was transmitted over a single-mode fiber-optic link from Deep Space Station (DSS) 13 to DSS 12 and back. The background leading up to the experiment and the significance of stable reference frequency distribution in the Deep Space Network (DSN) is discussed. Also described are the experiment, including the fiber-optic link, the measurement method and equipment, and finally the results of the experiment.

  19. Fiber optic probe for light scattering measurements

    DOEpatents

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

    1993-01-01

    This invention is comprised of a fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman- scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.

  20. Fiber optic probe for light scattering measurements

    DOEpatents

    Nave, Stanley E.; Livingston, Ronald R.; Prather, William S.

    1995-01-01

    A fiber optic probe and a method for using the probe for light scattering analyses of a sample. The probe includes a probe body with an inlet for admitting a sample into an interior sample chamber, a first optical fiber for transmitting light from a source into the chamber, and a second optical fiber for transmitting light to a detector such as a spectrophotometer. The interior surface of the probe carries a coating that substantially prevents non-scattered light from reaching the second fiber. The probe is placed in a region where the presence and concentration of an analyte of interest are to be detected, and a sample is admitted into the chamber. Exciting light is transmitted into the sample chamber by the first fiber, where the light interacts with the sample to produce Raman-scattered light. At least some of the Raman-scattered light is received by the second fiber and transmitted to the detector for analysis. Two Raman spectra are measured, at different pressures. The first spectrum is subtracted from the second to remove background effects, and the resulting sample Raman spectrum is compared to a set of stored library spectra to determine the presence and concentration of the analyte.

  1. Optical fiber sensors for spacecraft applications

    NASA Astrophysics Data System (ADS)

    Friebele, E. J.; Askins, C. G.; Bosse, A. B.; Kersey, A. D.; Patrick, H. J.; Pogue, W. R.; Putnam, M. A.; Simon, W. R.; Tasker, F. A.; Vincent, W. S.; Vohra, S. T.

    1999-12-01

    Optical fiber sensors offer a number of advantages for spacecraft applications. A principal application is strain sensing for structural health monitoring, shape determination, and spacecraft qualification testing. This paper will review the results of recent work at the Naval Research Laboratory where optical fiber strain sensors have been used on spacecraft structures and ground test hardware. The sensors have been both surface mounted to the structure and embedded in fiber-reinforced polymer composites. The issue of potential strength reduction of high-performance composites due to embedded optical fiber sensors and leads has been studied, low-cost fabrication of tubular struts with embedded sensors has been demonstrated, and a novel technique for fiber ingress-egress from composite parts has been developed. Applications of fiber sensors discussed in this paper include distributed dynamic strain monitoring of a honeycomb composite plate and a lightweight reflector during acoustic qualification tests, ultrahigh-sensitivity static strain and temperature measurements for precision structures, and on-line system identification of a lightweight laboratory truss.

  2. Practical circular-polarization-maintaining optical fiber.

    PubMed

    Huang, H C

    1997-09-20

    The author describes a new idea for making circular-polarization-maintaining optical fiber with an existing fabrication technique. The method simply requires one to spin at a constant rate a special preform consisting of only one off-axis stress-applying element in addition to the on-axis core. Measurements taken with such a fiber specimen verify the existence of circular eigenmodes, the ease of joining or splicing two fiber segments, the tolerance to macrobending with a small radius, etc. Good agreement exists between the experimental data and the theoretical analysis. Prospective applications are discussed.

  3. Optical fiber hybridization assay fluorosensor

    NASA Astrophysics Data System (ADS)

    Pilevar, Saeed; Davis, Christopher C.; Hodzic, Vildana; Portugal, Frank

    1999-04-01

    The present work describes an all-fiber hybridization assay sensor that relies on the evanescent field excitation of fluorescence from surface-bound fluorophores. The evanescent field is made accessible through the use of a long adiabatically tapered single-mode fiber probe. A semiconductor laser operating at 785 nm wavelength is used in a pulsed mode to excite fluorescence in the tapered region of a fiber probe using the near-infrared fluorophore IRD 41. We have carried out real-time hybridization tests for IRD 41-labeled oligonucleotide at various probe concentrations binding to complementary oligonucleotide cross-linked to the tapered fiber surface. Short oligonucleotides (20-mer) bound to the fiber surface have been used to detect near-infrared dye labeled complementary sequences at sub-nanomolar levels. Sandwich assays with total RNA were conducted to examine the capability of the biosensor for detecting bacterial cells using rRNA as the target. The results indicate that this fluorosensor is capable of detecting H. pylori in a sandwich assay at picomolar concentrations.

  4. In-line fiber optic interferometric sensors in single-mode fibers.

    PubMed

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

    2012-01-01

    In-line fiber optic interferometers have attracted intensive attention for their potential sensing applications in refractive index, temperature, pressure and strain measurement, etc. Typical in-line fiber-optic interferometers are of two types: Fabry-Perot interferometers and core-cladding-mode interferometers. It's known that the in-line fiber optic interferometers based on single-mode fibers can exhibit compact structures, easy fabrication and low cost. In this paper, we review two kinds of typical in-line fiber optic interferometers formed in single-mode fibers fabricated with different post-processing techniques. Also, some recently reported specific technologies for fabricating such fiber optic interferometers are presented.

  5. High-density fiber optic biosensor arrays

    NASA Astrophysics Data System (ADS)

    Epstein, Jason R.; Walt, David R.

    2002-02-01

    Novel approaches are required to coordinate the immense amounts of information derived from diverse genomes. This concept has influenced the expanded role of high-throughput DNA detection and analysis in the biological sciences. A high-density fiber optic DNA biosensor was developed consisting of oligonucleotide-functionalized, 3.1 mm diameter microspheres deposited into the etched wells on the distal face of a 500 micrometers imaging fiber bundle. Imaging fiber bundles containing thousands of optical fibers, each associated with a unique oligonucleotide probe sequence, were the foundation for an optically connected, individually addressable DNA detection platform. Different oligonucleotide-functionalized microspheres were combined in a stock solution, and randomly dispersed into the etched wells. Microsphere positions were registered from optical dyes incorporated onto the microspheres. The distribution process provided an inherent redundancy that increases the signal-to-noise ratio as the square root of the number of sensors examined. The representative amount of each probe-type in the array was dependent on their initial stock solution concentration, and as other sequences of interest arise, new microsphere elements can be added to arrays without altering the existing detection capabilities. The oligonucleotide probe sequences hybridize to fluorescently-labeled, complementary DNA target solutions. Fiber optic DNA microarray research has included DNA-protein interaction profiles, microbial strain differentiation, non-labeled target interrogation with molecular beacons, and single cell-based assays. This biosensor array is proficient in DNA detection linked to specific disease states, single nucleotide polymorphism (SNP's) discrimination, and gene expression analysis. This array platform permits multiple detection formats, provides smaller feature sizes, and enables sensor design flexibility. High-density fiber optic microarray biosensors provide a fast

  6. Advanced optical condition monitoring. [of rocket engines

    NASA Technical Reports Server (NTRS)

    Cross, G.; Barkhoudarian, S.

    1991-01-01

    The application of Advanced Optical Condition Monitoring to optical leak detection and plume spectrometry is discussed. The development of these selected sensors for propulsion system monitoring is addressed.

  7. Fiber-optic sensors for aerospace electrical measurements - An update

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1991-01-01

    The authors report the progress made on the development of aerospace current and voltage sensors which use fiber-optic and optical sensing heads. These sensors are presently designed to cover ac frequencies from 60 Hz to 20 kHz. The current sensor, based on the Faraday effect in optical fiber, is in advanced development after some initial testing. The emphasis is on packaging methods and ways to maintain consistent sensitivity with changes in temperature. The voltage sensor, utilizing the Pockels effect in a crystal, has excelled in temperature tests. The authors report on the development of these sensors. The authors also relate the technology used in the sensors, the results of evaluation, improvements being made, and the future direction of the work.

  8. Fiber optic coherent laser radar 3D vision system

    SciTech Connect

    Clark, R.B.; Gallman, P.G.; Slotwinski, A.R.; Wagner, K.; Weaver, S.; Xu, Jieping

    1996-12-31

    This CLVS will provide a substantial advance in high speed computer vision performance to support robotic Environmental Management (EM) operations. This 3D system employs a compact fiber optic based scanner and operator at a 128 x 128 pixel frame at one frame per second with a range resolution of 1 mm over its 1.5 meter working range. Using acousto-optic deflectors, the scanner is completely randomly addressable. This can provide live 3D monitoring for situations where it is necessary to update once per second. This can be used for decontamination and decommissioning operations in which robotic systems are altering the scene such as in waste removal, surface scarafacing, or equipment disassembly and removal. The fiber- optic coherent laser radar based system is immune to variations in lighting, color, or surface shading, which have plagued the reliability of existing 3D vision systems, while providing substantially superior range resolution.

  9. Optical fiber sensor development for turbine applications

    NASA Astrophysics Data System (ADS)

    Dunphy, James R.; Meltz, Gerald

    1989-07-01

    A twin-core optical fiber sensor is being developed for application to turbine engine diagnostics. It promises advantages of small, nonintrusive dimensions, inherent immunity to EMI, high temperature durability, and the capability to perform static strain and temperature measurements simultaneously. This paper summarizes the sensor concept, nonrotating risk reduction experiments, and rotating demonstration tests. During these experiments, the optical fiber sensors were attached to modified F100 turbine disks and operated in extreme conditions with temperatures higher than 1200 F, strains approaching 3000 microstrain, and spin rates greater than 7000 rpm.

  10. Application of optical fibers in microfluidic structures

    NASA Astrophysics Data System (ADS)

    Stadnik, Dorota; Brzozka, Zbigniew; Dybko, Artur

    2004-09-01

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

  11. Spaceborne Fiber Optic Data Bus (SFODB)

    NASA Technical Reports Server (NTRS)

    Bretthauer, Joy W.; Chalfant, Chuck H.; Orlando, Fred J.; Parkerson, P.; Rezek, Ed; Sawyer, Marc

    1999-01-01

    Spaceborne Fiber Optic Data Bus (SFODB) is an IEEE 1393 compliant, gigabit per second, fiber optic network specifically designed to support the real-time, on-board data handling requirements of remote sensing spacecraft. The network is fault tolerant highly reliable, and capable of withstanding the rigors of launch and the harsh space environment. SFODB achieves this operational and environmental performance while maintaining the small size, light weight, and low power necessary for spaceborne applications. On December 9, 1998, SFODB was successfully demonstrated at NASA's Goddard Space Flight Center (GSFC).

  12. New glass developments for fiber optics

    NASA Astrophysics Data System (ADS)

    Higby, Paige L.; Holst, Karen; Tabor, Kevin; James, William; Chase, Elizabeth; Pucilowski, Sally; Gober-Mangan, Elizabeth; Klimek, Ronald; Karetta, Frank; Schreder, Bianca

    2014-02-01

    Fiber optic components for lighting and imaging applications have been in use for decades. Recent requirements such as a need for RoHS compliance, attractive market pricing, or particular optical properties, such as numerical aperture (NA) or transmission, have required SCHOTT to develop and implement new glasses for these applications. From Puravis™ lead-free fibers for lighting applications, to new glasses for digital X-ray imaging and sensor applications, the challenges for SCHOTT scientists are considerable. Pertinent properties of these glasses and methods of determination for suitability will be discussed.

  13. Concentric core optical fiber with multiple-mode signal transmission

    DOEpatents

    Muhs, J.D.

    1997-05-06

    A concentric core optical fiber provides for the simultaneous but independent transmission of signals over a single optical fiber. The concentric optical fiber is constructed of a single-mode or multimode inner optical fiber defined by a core and a cladding of a lower index of refraction than the core and an outer optical fiber defined by additional cladding concentrically disposed around the cladding and of an index of refraction lower than the first mentioned cladding whereby the latter functions as the core of the outer optical fiber. By employing such an optical fiber construction with a single-mode inner core or optical fiber, highly sensitive interferometric and stable less sensitive amplitude based sensors can be placed along the same length of a concentric core optical fiber. Also, by employing the concentric core optical fiber secure telecommunications can be achieved via the inner optical fiber since an intrusion of the concentric optical fiber will first cause a variation in the light being transmitted through the outer optical fiber and this variation of light being used to trigger a suitable alarm indicative of the intrusion. 3 figs.

  14. Concentric core optical fiber with multiple-mode signal transmission

    DOEpatents

    Muhs, Jeffrey D.

    1997-01-01

    A concentric core optical fiber provides for the simultaneous but independent transmission of signals over a single optical fiber. The concentric optical fiber is constructed of a single-mode or multimode inner optical fiber defined by a core and a cladding of a lower index of refraction than the core and an outer optical fiber defined by additional cladding concentrically disposed around the cladding and of an index of refraction lower than the first mentioned cladding whereby the latter functions as the core of the outer optical fiber. By employing such an optical fiber construction with a single-mode inner core or optical fiber, highly sensitive interferometric and stable less sensitive amplitude based sensors can be placed along the same length of a concentric core optical fiber. Also, by employing the concentric core optical fiber secure telecommunications can be achieved via the inner optical fiber since an intrusion of the concentric optical fiber will first cause a variation in the light being transmitted through the outer optical fiber and this variation of light being used to trigger a suitable alarm indicative of the intrusion.

  15. Investigation of Optical Fibers for Nonlinear Optics.

    DTIC Science & Technology

    1984-04-17

    Verneuil method of crystal growth and the development of high temperature crystal preparation methods and the related ceramics and instrumentation...report describes the successful fabri- cation of more than a half dozen single crystal fibers using new growth techniques and progress with hybrid...5 2 CuCi single crystal ................................ 8 3 Schematic diagram of the capillary-fed Czochralski apparatus for growth of SC

  16. Power system applications of fiber optic sensors

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  17. Power system applications of fiber optic sensors

    SciTech Connect

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

    1986-06-01

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

  18. Power system applications of fiber optic sensors

    NASA Astrophysics Data System (ADS)

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

    1986-06-01

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

  19. Optical turbulence in fiber lasers.

    PubMed

    Wabnitz, Stefan

    2014-03-15

    We analyze the nonlinear stage of modulation instability in passively mode-locked fiber lasers leading to chaotic or noise-like emission. We present the phase-transition diagram among different regimes of chaotic emission in terms of the key cavity parameters: amplitude or phase turbulence, and spatio-temporal intermittency.

  20. Developments in fiber optics for distribution automation

    NASA Technical Reports Server (NTRS)

    Kirkham, H.; Friend, H.; Jackson, S.; Johnston, A.

    1991-01-01

    An optical fiber based communications system of unusual design is described. The system consists of a network of optical fibers overlaid on the distribution system. It is configured as a large number of interconnected rings, with some spurs. Protocols for access to and control of the network are described. Because of the way they function, the protocols are collectively called AbNET, in commemoration of the microbiologists' abbreviation Ab for antibody. Optical data links that could be optically powered are described. There are two versions, each of which has a good frequency response and minimal filtering requirements. In one, a conventional FM pulse train is used at the transmitter, and a novel form of phase-locked loop is used as demodulator. In the other, the FM transmitter is replaced with a pulse generator arranged so that the period between pulses represents the modulating signal. Transmitter and receiver designs, including temperature compensation methods, are presented. Experimental results are given.

  1. Stitching Techniques Advance Optics Manufacturing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Because NASA depends on the fabrication and testing of large, high-quality aspheric (nonspherical) optics for applications like the James Webb Space Telescope, it sought an improved method for measuring large aspheres. Through Small Business Innovation Research (SBIR) awards from Goddard Space Flight Center, QED Technologies, of Rochester, New York, upgraded and enhanced its stitching technology for aspheres. QED developed the SSI-A, which earned the company an R&D 100 award, and also developed a breakthrough machine tool called the aspheric stitching interferometer. The equipment is applied to advanced optics in telescopes, microscopes, cameras, medical scopes, binoculars, and photolithography."

  2. Ultrathin lensed fiber-optic probe for optical coherence tomography.

    PubMed

    Qiu, Y; Wang, Y; Belfield, K D; Liu, X

    2016-06-01

    We investigated and validated a novel method to develop ultrathin lensed fiber-optic (LFO) probes for optical coherence tomography (OCT) imaging. We made the LFO probe by attaching a segment of no core fiber (NCF) to the distal end of a single mode fiber (SMF) and generating a curved surface at the tip of the NCF using the electric arc of a fusion splicer. The novel fabrication approach enabled us to control the length of the NCF and the radius of the fiber lens independently. By strategically choosing these two parameters, the LFO probe could achieve a broad range of working distance and depth of focus for different OCT applications. A probe with 125μm diameter and lateral resolution up to 10μm was demonstrated. The low-cost, disposable and robust LFO probe is expected to have great potential for interstitial OCT imaging.

  3. Advanced optical manufacturing digital integrated system

    NASA Astrophysics Data System (ADS)

    Tao, Yizheng; Li, Xinglan; Li, Wei; Tang, Dingyong

    2012-10-01

    It is necessarily to adapt development of advanced optical manufacturing technology with modern science technology development. To solved these problems which low of ration, ratio of finished product, repetition, consistent in big size and high precision in advanced optical component manufacturing. Applied business driven and method of Rational Unified Process, this paper has researched advanced optical manufacturing process flow, requirement of Advanced Optical Manufacturing integrated System, and put forward architecture and key technology of it. Designed Optical component core and Manufacturing process driven of Advanced Optical Manufacturing Digital Integrated System. the result displayed effective well, realized dynamic planning Manufacturing process, information integration improved ratio of production manufactory.

  4. Analog Fiber Optic Recirculating Delay Line.

    DTIC Science & Technology

    1987-03-31

    signal is input through a BNC type connector and a corresponding optical analog signal is output via a single mode optical fiber. The transmitter...second functional transmitter subdivision. The stripline fix- ture board provides an impedance matching stripline from a BNC input connector to the RF...drive signal input pin of the laser hybrid. Other socket pins on this circuit board provide for the proper routing of sensor outputs to the

  5. Fiber-optic ground-truth thermometer

    SciTech Connect

    Ekdahl, C.A. Jr.; Forman, P.; Veeser, L.

    1993-07-01

    By making a high accuracy measurement of the optical length of a long fiber optic cable, the authors can determine the absolute temperature averaged over its length and the temperature of a material in contact with it. They describe how to set up such a measurement and use it to determine the average temperature of the surface of the earth over a large enough area to be useful as a ground truth calibration for a satellite imaging system.

  6. Neutron-induced defects in optical fibers

    SciTech Connect

    Rizzolo, S.; Morana, A.; Boukenter, A.; Ouerdane, Y.; Girard, S.; Cannas, M.; Boscaino, R.; Bauer, S.; Perisse, J.; Mace, J-R.; Nacir, B.

    2014-10-21

    We present a study on 0.8 MeV neutron-induced defects up to fluences of 10{sup 17} n/cm{sup 2} in fluorine doped optical fibers by using electron paramagnetic resonance, optical absorption and confocal micro-luminescence techniques. Our results allow to address the microscopic mechanisms leading to the generation of Silica-related point-defects such as E', H(I), POR and NBOH Centers.

  7. Fiber optics in meteorological instrumentation suites

    NASA Astrophysics Data System (ADS)

    Holton, Carvel E.; Parker, Matthew J.

    1999-12-01

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

  8. Detecting eavesdropping activity in fiber optic networks

    NASA Astrophysics Data System (ADS)

    MacDonald, Gregory G.

    The secure transmission of data is critical to governments, military organizations, financial institutions, health care providers and other enterprises. The primary method of securing in-transit data is though data encryption. A number of encryption methods exist but the fundamental approach is to assume an eavesdropper has access to the encrypted message but does not have the computing capability to decrypt the message in a timely fashion. Essentially, the strength of security depends on the complexity of the encryption method and the resources available to the eavesdropper. The development of future technologies, most notably quantum computers and quantum computing, is often cited as a direct threat to traditional encryption schemes. It seems reasonable that additional effort should be placed on prohibiting the eavesdropper from coming into possession of the encrypted message in the first place. One strategy for denying possession of the encrypted message is to secure the physical layer of the communications path. Because the majority of transmitted information is over fiber-optic networks, it seems appropriate to consider ways of enhancing the integrity and security of the fiber-based physical layer. The purpose of this research is to investigate the properties of light, as they are manifested in single mode fiber, as a means of insuring the integrity and security of the physical layer of a fiber-optic based communication link. Specifically, the approach focuses on the behavior of polarization in single mode fiber, as it is shown to be especially sensitive to fiber geometry. Fiber geometry is necessarily modified during the placement of optical taps. The problem of detecting activity associated with the placement of an optical tap is herein approached as a supervised machine learning anomaly identification task. The inputs include raw polarization measurements along with additional features derived from various visualizations of the raw data (the inputs are

  9. Optical Fiber Technology In Medicine

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryazard S.

    1986-01-01

    A digest of applications of optical fibre technology in biology and medicine is presented. We describe the topic from several main (according to our opinion) points of view, namely: place of optical fibre and some kinds of optoelectronic equipment among other optical biomedical apparatus, requirements imposed by biomedical environments on the construction of apparatus, possible areas of applications, main confinements of applications and further development. We present here our arbitrary understanding of directions of development of debated field. The bibliography of this problem is quoted and some works carried in this country are emphasized.

  10. Optical fiber strain sensor with improved linearity range

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

    1995-01-01

    A strain sensor is constructed from a two mode optical fiber. When the optical fiber is surface mounted in a straight line and the object to which the optical fiber is mounted is subjected to strain within a predetermined range, the light intensity of any point at the output of the optical fiber will have a linear relationship to strain, provided the intermodal phase difference is less than 0.17 radians.

  11. Study of fiber optics standardization, reliability, and applications

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The use of fiber optics in space applications is investigated. Manufacturers and users detailed the problems they were having with the use or manufacture of fiber optic components. The general consensus of all the companies/agencies interviewed is that fiber optics is a maturing technology and will definitely have a place in future NASA system designs. The use of fiber optics was found to have two main advantages - weight savings and increased bandwidth.

  12. Fiber optical asssembly for fluorescence spectrometry

    DOEpatents

    Piltch, Martin S.; Gray, Perry Clayton; Rubenstein, Richard

    2015-08-18

    System is provided for detecting the presence of an analyte of interest in a sample, said system comprising an elongated, transparent container for a sample; an excitation source in optical communication with the sample, wherein radiation from the excitation source is directed along the length of the sample, and wherein the radiation induces a signal which is emitted from the sample; and, at least two linear arrays disposed about the sample holder, each linear array comprising a plurality of optical fibers having a first end and a second end, wherein the first ends of the fibers are disposed along the length of the container and in proximity thereto; the second ends of the fibers of each array are bundled together to form a single end port.

  13. Multimode-Optical-Fiber Imaging Probe

    NASA Technical Reports Server (NTRS)

    Jackson, Deborah

    2000-01-01

    Currently, endoscopic surgery uses single-mode fiber-bundles to obtain in vivo image information inside orifices of the body. This limits their use to the larger natural bodily orifices and to surgical procedures where there is plenty of room for manipulation. The knee joint, for example can be easily viewed with a fiber optic viewer, but joints in the finger cannot. However, there are a host of smaller orifices where fiber endoscopy would play an important role if a cost effective fiber probe were developed with small enough dimensions (< 250 microns). Examples of beneficiaries of micro-endoscopes are the treatment of the Eustatian tube of the middle ear, the breast ducts, tear ducts, coronary arteries, fallopian tubes, as well as the treatment of salivary duct parotid disease, and the neuro endoscopy of the ventricles and spinal canal. To solve this problem, this work describes an approach for recovering images from. tightly confined spaces using multimode fibers and analytically demonstrates that the concept is sound. The proof of concept draws upon earlier works that concentrated on image recovery after two-way transmission through a multimode fiber as well as work that demonstrated the recovery of images after one-way transmission through a multimode fiber. Both relied on generating a phase conjugated wavefront which was predistorted with the characteristics of the fiber. The described approach also relies on generating a phase conjugated wavefront, but utilizes two fibers to capture the image at some intermediate point (accessible by the fibers, but which is otherwise visually unaccessible).

  14. Laser peening with fiber optic delivery

    DOEpatents

    Friedman, Herbert W.; Ault, Earl R.; Scheibner, Karl F.

    2004-11-16

    A system for processing a workpiece using a laser. The laser produces at least one laser pulse. A laser processing unit is used to process the workpiece using the at least one laser pulse. A fiber optic cable is used for transmitting the at least one laser pulse from the laser to the laser processing unit.

  15. Apparatus for Teaching Physics: Optical Fiber Communications.

    ERIC Educational Resources Information Center

    Throckmorton, Carl; Dey, Joe

    1988-01-01

    Describes a demonstration of the transmission of data signals from one microcomputer to another using an optical fiber line. Discusses the set-up method and demonstration steps for sending program and graphics. Provides a block diagram of the system and two circuit diagrams. (YP)

  16. Fiber-Optic Lateral-Displacement Sensor

    NASA Technical Reports Server (NTRS)

    Roschak, Edmund J.

    1987-01-01

    Proposed fiber-optic sensor monitors axial position of shaft or bearing in turbomachine. Device senses position of non-magnetic as well as magnetic material and calibrates before assembly in machine. More compact. Concept extends to measure rotational speed of shaft.

  17. Low attenuation optical fiber of deuterated polymer

    SciTech Connect

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

    1985-04-16

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

  18. FIBER OPTIC BIOSENSOR FOR DNA DAMAGE

    EPA Science Inventory

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

  19. Stabilized fiber-optic frequency distribution system

    NASA Technical Reports Server (NTRS)

    Primas, L. E.; Lutes, G. F.; Sydnor, R. L.

    1989-01-01

    A technique for stabilizing reference frequencies transmitted over fiber-optic cable in a frequency distribution system is discussed. The distribution system utilizes fiber-optic cable as the transmission medium to distribute precise reference signals from a frequency standard to remote users. The stability goal of the distribution system is to transmit a 100-MHz signal over a 22-km fiber-optic cable and maintain a stability of 1 part in 10(17) for 1000-second averaging times. Active stabilization of the link is required to reduce phase variations produced by environmental effects, and is achieved by transmitting the reference signal from the frequency standard to the remote unit and then reflecting back to the reference unit over the same optical fiber. By comparing the phase of the transmitted and reflected signals at the reference unit, phase variations of the remote signal can be measured. An error voltage derived from the phase difference between the two signals is used to add correction phase.

  20. Containerless Manufacture of Glass Optical Fibers

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.; Ethridge, E. C.

    1985-01-01

    Contamination and crystallization reduced in proposed process. Solid optical fiber drawn from an acoustically levitated lump of molten glass. New material added in solid form, melted and then moved into main body of molten glass. Single axis acoustic levitation furnances levitate glass melts at temperature up to about 700 degrees C. Processing in unit limited to low-melting temperature glasses.

  1. Luminescence Originating in an Optical Fiber

    DTIC Science & Technology

    1988-10-28

    TIME COVERED /1 14. DATE OF REPORT (Year Month, Oay) S.PAGE COUNT Technical FROM TO_ _ 28 October 1988 12 16. SUPPLEMENTARY NOTATION Applied ... Spectroscopy 17. COSATI CODES18. SUB Eg.TERMS (Continue on reverse if necessary and identify by block number) FIED OUPU Optical Fibers, Luminescence, Sensors

  2. Cascaded Bragg scattering in fiber optics.

    PubMed

    Xu, Y Q; Erkintalo, M; Genty, G; Murdoch, S G

    2013-01-15

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

  3. Human psychophysiological activity monitoring methods using fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Zyczkowski, M.; Uzieblo-Zyczkowska, B.

    2010-10-01

    The paper presents the concept of fiber optic sensor system for human psycho-physical activity detection. A fiber optic sensor that utilizes optical phase interferometry or intensity in modalmetric to monitor a patient's vital signs such as respiration cardiac activity, blood pressure and body's physical movements. The sensor, which is non-invasive, comprises an optical fiber interferometer that includes an optical fiber proximately situated to the patient so that time varying acusto-mechanical signals from the patient are coupled into the optical fiber. The system can be implemented in embodiments ranging form a low cost in-home to a high end product for in hospital use.

  4. Heating and Burning of Optical Fibers and Cables by Light Scattered from Bubble Train Formed by Optical Fiber Fuse

    NASA Astrophysics Data System (ADS)

    Yamada, Makoto; Tomoe, Akisumi; Kinoshita, Takahiro; Koyama, Osanori; Katuyama, Yutaka; Shibuya, Takashi

    We investigate in detail the scattering properties and heating characteristics in various commercially available optical fibers and fiber cables when a bubble train forms in the middle of the fiber as a result of the fiber fuse phenomenon that occurs when a high power signal is launched into the fiber. We found theoretically and experimentally that almost all the optical light is scattered at the top of the bubble train. The scattered light heats UV coated fiber, nylon jacketed silica fiber, fire-retardant jacketed fiber (PVC or FRPE jacketed fiber) and fire-retardant fiber cable (PVC or FRPE fiber cable), to around 100, over 200 and over 600°C, respectively, and finally the fiber burns and is destroyed at a launched optical power of 3W. Furthermore, it is confirmed that the combustion does not spread when we use fire retardant jacketed fibers.

  5. Fiber optic liquid refractive index sensor

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Vanita; Gangwar, Rahul Kumar; Singh, Vinod Kumar

    2015-08-01

    In this present work we report fabrication of fiber optic liquid refractive index (RI) measurement sensor based on Michelson Interferometer method. This sensor was assembled by using graded index multimode (MM) fiber with core diameter 50 µm and the cladding of fiber was removed by simple chemical method. To perform this experiment a 2×2 3dB coupler is used. The fiber ends are then immersed in solvent and solution to provide reference and refractive index measurements, respectively. This method was successfully used to measure refractive index of Sodium Chloride (NaCl)-Water solution at different concentrations. The fringe contrast sensitivity of device is 92.90 dB/RIU measured in the RI range from 1.34 to 1.42 which is better than Mach-Zehnder Interferometer sensor [1] and Fabry perot based sensor [2]. The fabrication of sensor is simple, low cost and highly sensitive.

  6. Pulse Shepherding in Nonlinear Fiber Optics

    NASA Technical Reports Server (NTRS)

    Yeh, C.; Bergman, L.

    1996-01-01

    In a wavelength division multiplexed fiber system, where pulses on different wavelength beams may co-propagate in a single mode fiber, the cross-phase-modulation (CPM) effects caused by the nonlinearity of the optical fiber are unavoidable. In other words, pulses on different wavelength beams can interact with and affect each other through the intensity dependence of the refractive index of the fiber. Although CPM will not cause energy to be exchanged among the beams, the pulse shapes and locations on these beams can be altered significantly. This phenomenon makes possible the manipulation and control of pulses co-propagating on different wavelength beams through the introduction of a shepherd pulse at a separate wavelength. How this can be accomplished is demonstrated in this paper.

  7. Application of fiber optics in spacecraft

    NASA Astrophysics Data System (ADS)

    Johnston, A. R.; Bergman, L. A.

    1980-01-01

    The unique requirements placed on an optical fiber data system in space are briefly reviewed in this paper. These include temperature extremes, particle radiation, and, in some cases, a stringent electrical power budget. An overriding need is for the best possible reliability. Results related to the power consumption of a fiber terminal pair are reported, with the conclusion that a 32-port transmission star bus configuration could be operated error-free at 10 Mbits/s on 1/8 watt per transmitting terminal. The design of a transmitter terminal optimized for low idling power consumption is discussed. Although the electronic elements on a spacecraft are protected, the fiber cable may be subjected to large temperature extremes. Measured effects of temperature on fibers and cables are discussed and related to bus design. Radiation effects are briefly reviewed, with special reference to the long-duration low dose rate environment of a spacecraft.

  8. Wide band fiber-optic communications

    NASA Technical Reports Server (NTRS)

    Bates, Harry E.

    1993-01-01

    A number of optical communication lines are now in use at the Kennedy Space Center (KSC) for the transmission of voice, computer data and video signals. At the present time most of these channels utilize a single carrier wavelength centered near 1300 nm. As a result of previous work the bandwidth capacity of a number of these channels is being increased by transmitting another signal in the 1550 nm region on the same fiber. This is accomplished by means of wavelength division multiplexing (WDM). It is therefore important to understand the bandwidth properties of the installed fiber plant. This work developed new procedures for measuring the bandwidth of fibers in both the 1300nm and 1550nm region. In addition, a preliminary study of fiber links terminating in the Engineering Development Laboratory was completed.

  9. Optical Fiber Delay Line Signal Processing.

    NASA Astrophysics Data System (ADS)

    Newton, Steven Arthur

    The delay line transversal filter is a basic component in analog signal processing systems. Unfortunately, conventional delay line devices, such as those that use surface acoustic waves, are largely limited to operation at frequencies of several hundred megahertz and below. In this work, single-mode optical fiber has been used as a delay medium to make transversal filters that extend this kind of signal processing to frequencies of one gigahertz and above. Single-mode optical fiber is an excellent delay medium because it exhibits extremely low loss and dispersion. By efficiently collecting, weighting, and combining signals extracted from a fiber delay line, single-mode fiber can be used, not only to transmit broadband signals, but to process them as well. The goals of the work have been to study efficient tapping mechanisms, and to construct fiber transversal filters capable of performing some basic signal processing functions. Several different tapped and recirculating delay line prototypes have been fabricated using a variety of tapping techniques, including macrobending and evanescent field coupling. These devices have been used to demonstrate basic signal processing functions, such as code generation, convolution, correlation, and frequency filtering, at frequencies that exceed those possible using conventional delay line technologies. Fiber recirculating delay line loops have also been demonstrated as transient memories for the temporary storage of signals and as a means of time division multiplexing via data rate transformation. These devices are the building blocks that are necessary to make systems capable of performing complex signal processing functions. With the recent development of high speed optical sources and detectors to interface with fiber systems of this kind, the real time processing of signals having bandwidths of tens of gigahertz is envisioned.

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

    PubMed Central

    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

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

    PubMed

    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.

  12. A novel differential optical fiber accelerometer

    NASA Astrophysics Data System (ADS)

    Pi, Shaohua; Zhao, Jiang; Hong, Guangwei; Jia, Bo

    2013-08-01

    The development of sensitive fiber-optic accelerometers is a subject of continuing interest. To acquire high resolution, Michelson phase interferometric techniques are widely adopted. Among the variety structures, the compliant cylinder approach is particularly attractive due to its high sensitivity that is defined as the induced phase shift per applied acceleration. While the two arms of Michelson interferometer should be at the same optical path, it is inconvenient to adjust the two arms' length to equal, also the polarization instability and phase random drift will cause a signal decline. To overcome these limitations, a novel optical fiber accelerometer based on differential interferometric techniques is proposed and investigated. The interferometer is a Sagnac-like white light interferometer, which means the bandwidth of laser spectrum can be as wide as tens nanometers. This interferometer was firstly reported by Levin in 1990s. Lights are divided to two paths before entering the coupler. To induce time difference, one passes through a delay arm and another goes a direct arm. After modulated by the sensing component, they reflect to opposite arm. The sensing part is formed by a seismic mass that is held to only one compliant cylinder, where the single-mode optical fiber is wrapped tightly. When sticking to vibrations, the cylinder compresses or stretches as a spring. The corresponding changes in cylinder circumference lead to strain in the sensing fibers, which is detected as an optical phase shift by the interferometer. The lights from two arms reach the vibration source at different time, sensing a different accelerate speed; produce a different optic path difference. Integrating the dissimilarity of the accelerated speed by time can obtain the total acceleration graph. A shaker's vibration has been tested by the proposed accelerometer referring to a standard piezoelectric accelerometer. A 99.8% linearity of the optical phase shift to the ground acceleration

  13. 46 CFR 111.60-6 - Fiber optic cable.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 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)...

  14. 46 CFR 111.60-6 - Fiber optic cable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 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)...

  15. 21 CFR 872.4620 - Fiber optic dental light.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

  16. 21 CFR 872.4620 - Fiber optic dental light.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 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...

  17. 46 CFR 111.60-6 - Fiber optic cable.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 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)...

  18. 21 CFR 872.4620 - Fiber optic dental light.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  19. 46 CFR 111.60-6 - Fiber optic cable.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 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)...

  20. 46 CFR 111.60-6 - Fiber optic cable.

    Code of Federal Regulations, 2010 CFR

    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)...

  1. 21 CFR 872.4620 - Fiber optic dental light.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  2. 21 CFR 872.4620 - Fiber optic dental light.

    Code of Federal Regulations, 2010 CFR

    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...

  3. Advanced development of the nested fiber filter

    SciTech Connect

    Litt, R.D.; Glover, R.C.; Raghavan, J.K.

    1993-05-01

    Battelle and DOE have been developing the Nested Fiber Filter for high-temperature, high-pressure particulate control as applied to advanced coal-fired power systems. The current program represents a focused effort to develop cleaning techniques for the NFF at pilot plant scale. The filter consists of a 10-inch deep nest of stainless steel fibers collecting particles as dendrites on individual fibers. Tests with a 6-sq ft Nested Fiber Filter (NFF) have demonstrated greater than 99% particulate capture over a limited number of operating hours. Design, development, and testing a 6-sq ft module proceeded in three sequential stages. The NFF test module was integrated with a fluidized bed combustor to provide a realistic particulate laden gas to the NFF. Initial problems with gas and particulate bypassing plus ineffective cleaning by acoustic drivers led to a series of tests on a 1.5 sq ft section of the NFF. The fiber bed was slightly compressed to further prevent voids forming at the side walls during the vibration cleaning cycle. A mechanical vibrator was coupled with the pulse combustor to effectively clean/regenerate the NFF over a limited number of cycles. Testing resumed with the 6-sq ft test module and the above modifications. Two tests totaling 15 hours of operation and 14 repetitive cycles are summarized here and demonstrated the NFF performance. The preliminary engineering and economic evaluation showed the NFF to be cost-competitive with the ceramic cross-flow filter and the granular bed filter. Capital cost for a NFF on a 330 MW PFBC is estimated to be $42.9 million or $130/kW. The total plant cost for a PFBC system including the NFF is estimated to be $1,274/kW. This compares to $1,261/kW for a PFBC plus ceramic cross-flow filter or $1,351/kW for a PFBC plus granular bed filter.

  4. OPTICAL FIBER SENSOR TECHNOLOGIES FOR EFFICIENT AND ECONOMICAL OIL RECOVERY

    SciTech Connect

    Anbo Wang; Kristie L. Cooper; Gary R. Pickrell

    2003-06-01

    Efficient recovery of petroleum reserves from existing oil wells has been proven to be difficult due to the lack of robust instrumentation that can accurately and reliably monitor processes in the downhole environment. Commercially available sensors for measurement of pressure, temperature, and fluid flow exhibit shortened lifetimes in the harsh downhole conditions, which are characterized by high pressures (up to 20 kpsi), temperatures up to 250 C, and exposure to chemically reactive fluids. Development of robust sensors that deliver continuous, real-time data on reservoir performance and petroleum flow pathways will facilitate application of advanced recovery technologies, including horizontal and multilateral wells. This is the final report for the four-year program ''Optical Fiber Sensor Technologies for Efficient and Economical Oil Recovery'', funded by the National Petroleum Technology Office of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech from October 1, 1999 to March 31, 2003. The main objective of this research program was to develop cost-effective, reliable optical fiber sensor instrumentation for real-time monitoring of various key parameters crucial to efficient and economical oil production. During the program, optical fiber sensors were demonstrated for the measurement of temperature, pressure, flow, and acoustic waves, including three successful field tests in the Chevron/Texaco oil fields in Coalinga, California, and at the world-class oil flow simulation facilities in Tulsa, Oklahoma. Research efforts included the design and fabrication of sensor probes, development of signal processing algorithms, construction of test systems, development and testing of strategies for the protection of optical fibers and sensors in the downhole environment, development of remote monitoring capabilities allowing real-time monitoring of the field

  5. Fiber optics spectrochemical emission sensors

    DOEpatents

    Griffin, Jeffrey W.; Olsen, Khris B.

    1992-01-01

    A method of in situ monitoring of a body of a fluid stored in a tank or groundwater or vadose zone gases in a well for the presence of selected chemical species uses a probe insertable into the well or tank via a cable and having electrical apparatus for exciting selected chemical species in the body of fluid. The probe can have a pair of electrodes for initiating a spark or a plasma cell for maintaining a plasma to excite the selected chemical species. The probe also has optical apparatus for receiving optical emissions emitted by the excited species and optically transmitting the emissions via the cable to an analysis location outside the well. The analysis includes detecting a selected wavelength in the emissions indicative of the presence of the selected chemical species. A plurality of probes can be suspended at an end of a respective cable, with the transmitting and analyzing steps for each probe being synchronized sequentially for one set of support equipment and instrumentation to monitor at multiple test points. The optical apparatus is arranged about the light guide axis so that the selected chemical species are excited the fluid in alignment with the light guide axis and optical emissions are received from the excited chemical species along such axis.

  6. Fiber optics spectrochemical emission sensors

    DOEpatents

    Griffin, J.W.; Olsen, K.B.

    1992-02-04

    A method is described of in situ monitoring of a body of a fluid stored in a tank or groundwater or vadose zone gases in a well for the presence of selected chemical species. The method uses a probe insertable into the well or tank via a cable and having an electrical apparatus for exciting selected chemical species in the body of fluid. The probe can have a pair of electrodes for initiating a spark or a plasma cell for maintaining a plasma to excite the selected chemical species. The probe also has an optical apparatus for receiving optical emissions emitted by the excited species and optically transmitting the emissions via the cable to an analysis location outside the well. The analysis includes detecting a selected wavelength in the emissions indicative of the presence of the selected chemical species. A plurality of probes can be suspended at an end of a respective cable, with the transmitting and analyzing steps for each probe being synchronized sequentially for one set of support equipment and instrumentation to monitor at multiple test points. The optical apparatus is arranged about the light guide axis so that the selected chemical species are excited in the fluid in alignment with the light guide axis. Optical emissions are received from the excited chemical species along such axis. 18 figs.

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

    DOEpatents

    Kramer, Daniel P.

    1994-08-09

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

  8. Fiber-optic shock position sensor

    SciTech Connect

    Weiss, J.D.

    1993-03-01

    This report describes work performed for the development of a fiber-optic shock position sensor used to measure the location of a shock front in the neighborhood of a nuclear explosion. Such a measurement would provide a hydrodynamic determination of nuclear yield. The original proposal was prompted by the Defense Nuclear Agency's interest in replacing as many electrical sensors as possible with their optical counterparts for the verification of a treaty limiting the yield of a nuclear device used in underground testing. Immunity to electromagnetic pulse is the reason for the agency's interest; unlike electrical sensors and their associated cabling, fiber-optic systems do not transmit to the outside world noise pulses from the device containing secret information.

  9. Digitally enhanced optical fiber frequency reference.

    PubMed

    McRae, Terry G; Ngo, Silvie; Shaddock, Daniel A; Hsu, Magnus T L; Gray, Malcolm B

    2014-04-01

    We use digitally enhanced heterodyne interferometry to measure the stability of optical fiber laser frequency references. Suppression of laser frequency noise by over four orders of magnitude is achieved using post processing time delay interferometry, allowing us to measure the mechanical stability for frequencies as low as 100 μHz. The performance of the digitally enhanced heterodyne interferometer platform used here is not practically limited by the dynamic range or bandwidth issues that can occur in feedback stabilization systems. This allows longer measurement times, better frequency discrimination, a reduction in spatially uncorrelated noise sources and an increase in interferometer sensitivity. An optical fiber frequency reference with the stability reported here, over a signal band of 20 mHz-1 Hz, has potential for use in demanding environments, such as space-based interferometry missions and optical flywheel applications.

  10. Fiber optic configurations for local area networks

    NASA Technical Reports Server (NTRS)

    Nassehi, M. M.; Tobagi, F. A.; Marhic, M. E.

    1985-01-01

    A number of fiber optic configurations for a new class of demand assignment multiple-access local area networks requiring a physical ordering among stations are proposed. In such networks, the data transmission and linear-ordering functions may be distinguished and be provided by separate data and control subnetworks. The configurations proposed for the data subnetwork are based on the linear, star, and tree topologies. To provide the linear-ordering function, the control subnetwork must always have a linear unidirectional bus structure. Due to the reciprocity and excess loss of optical couplers, the number of stations that can be accommodated on a linear fiber optic bus is severely limited. Two techniques are proposed to overcome this limitation. For each of the data and control subnetwork configurations, the maximum number of stations as a function of the power margin, for both reciprocal and nonreciprocal couplers, is computed.

  11. Optical fiber-based CDMA networks

    NASA Astrophysics Data System (ADS)

    Gameiro, Atilio M. S.

    1996-01-01

    In this communication we consider the use of an optical fiber based fixed infrastructure for code division multiple access (CDMA) mobile networks. In such a scenario, the base stations are linked to the central station through optical fiber using subcarrier multiplexing (SCM) technology. One of the major problems associated with optical SCM is the nonlinearity of the laser diodes (LD). In this communication we model the LD as a memoryless nonlinearity and evaluate the effect of the nonlinearity on the SCM transmission CDMA signals. We find that the behavior departs significantly from what happens in FDMA and depends critically on the nonlinearity of the LD being a compressing or an expanding one. In the former case significant performance degradation may occur whereas for the latter the degradation is usually not dramatic.

  12. Fiber Optic Magnetic Sensor Research.

    DTIC Science & Technology

    1983-02-28

    interferometer It is shown that single-mode fibres mane to the response of the sensor to variations in the tern- offer the possibility of high-speed, high...qualitative study of the response of a fibre of millidegrees Kelvin. was etimated by mean, of a thermo- interferometer to impulse heating has recently been...8217 The interferometer was composed en- tirely of single-mode optical fibre (liT. 5 pm core diameter) dT/dt C 1(I2R - HT) (I) with an optical path

  13. Enabling technologies for fiber optic sensing

    NASA Astrophysics Data System (ADS)

    Ibrahim, Selwan K.; Farnan, Martin; Karabacak, Devrez M.; Singer, Johannes M.

    2016-04-01

    In order for fiber optic sensors to compete with electrical sensors, several critical parameters need to be addressed such as performance, cost, size, reliability, etc. Relying on technologies developed in different industrial sectors helps to achieve this goal in a more efficient and cost effective way. FAZ Technology has developed a tunable laser based optical interrogator based on technologies developed in the telecommunication sector and optical transducer/sensors based on components sourced from the automotive market. Combining Fiber Bragg Grating (FBG) sensing technology with the above, high speed, high precision, reliable quasi distributed optical sensing systems for temperature, pressure, acoustics, acceleration, etc. has been developed. Careful design needs to be considered to filter out any sources of measurement drifts/errors due to different effects e.g. polarization and birefringence, coating imperfections, sensor packaging etc. Also to achieve high speed and high performance optical sensing systems, combining and synchronizing multiple optical interrogators similar to what has been used with computer/processors to deliver super computing power is an attractive solution. This path can be achieved by using photonic integrated circuit (PIC) technology which opens the doors to scaling up and delivering powerful optical sensing systems in an efficient and cost effective way.

  14. Establishing a fiber-optic-based optical neural interface.

    PubMed

    Adamantidis, Antoine R; Zhang, Feng; de Lecea, Luis; Deisseroth, Karl

    2014-08-01

    Selective expression of opsins in genetically defined neurons makes it possible to control a subset of neurons without affecting nearby cells and processes in the intact brain, but light must still be delivered to the target brain structure. Light scattering limits the delivery of light from the surface of the brain. For this reason, we have developed a fiber-optic-based optical neural interface (ONI), which allows optical access to any brain structure in freely moving mammals. The ONI system is constructed by modifying the small animal cannula system from PlasticsOne. The system for bilateral stimulation consists of a bilateral cannula guide that has been stereotactically implanted over the target brain region, a screw cap for securing the optical fiber to the animal's head, a fiber guard modified from the internal cannula adapter, and a bare fiber whose length is customized based on the depth of the target region. For unilateral stimulation, a single-fiber system can be constructed using unilateral cannula parts from PlasticsOne. We describe here the preparation of the bilateral ONI system and its use in optical stimulation of the mouse or rat brain. Delivery of opsin-expressing virus and implantation of the ONI may be conducted in the same surgical session; alternatively, with a transgenic animal no opsin virus is delivered during the surgery. Similar procedures are useful for deep or superficial injections (even for neocortical targets, although in some cases surface light-emitting diodes or cortex-apposed fibers can be used for the most superficial cortical targets).

  15. Optical fiber Bragg gratings for tunnel surveillance

    NASA Astrophysics Data System (ADS)

    Nellen, Philipp M.; Frank, Andreas; Broennimann, Rolf; Sennhauser, Urs J.

    2000-06-01

    We report on application tests of novel sensor elements for long term surveillance of tunnels. The sensors are made of glass fiber reinforced polymers (GFRP) with embedded optical fiber Bragg gratings. The tests were made in a tunnel near Sargans in Switzerland and we will present strain and temperature data of more than one year of operation of the sensor elements. Two sensor types were tested. First, GFRP rockbolts with a diameter of 22 mm were produced. They have a load-bearing function as anchors for tunnel or mine roofs and in addition measure distributed strain fields and temperature with embedded optical fiber Bragg grating arrays. Rockbolts are key elements during construction and operation of tunnels. Data about strain inside the rockbolts can support decision about precautions to be taken and reveal information about the long term movement of the rock. Second, thin and flexible GFRP wires of 3 mm in diameter were found to be robust and versatile sensors not only for tunnel surveillance but for many civil engineering applications where they can be attached or embedded (e.g., in concrete). The fabrication of both sensor types and solutions for the connection of the embedded fiber sensors to a fiber cable will be presented. Moreover, laboratory and tunnel data of functionality and long term stability tests will be discussed and compared.

  16. Transmission of straight and curved multimode optical fibers

    NASA Astrophysics Data System (ADS)

    Melnik, Ivan S.; Kravchenko, Igor; Denisov, Nikolay A.; Dets, Sergiy M.; Rusina, Tatyana V.

    1995-01-01

    Bent multimode optical fibers were studied using a 3D ray tracing program. Effect of fiber bending increased with smaller input aperture beams. Transmission of fibers decreased for the longer proximal straight part of the fiber. Significant focusing effect and output light redistribution were detected if a proximal straight part of the fiber was less than 1 fiber diameter. Transmission of hollow waveguides considerably depended on the inner surface quality. Calculated data were in accordance with experimental measurements of fiber transmission and output light distribution. Ray tracing is a useful approach to simulate different delivery systems using optical fibers and hollow waveguides.

  17. All-Fiber Optical Faraday Mirror Using 56-wt%-Terbium-Doped Fiber

    SciTech Connect

    Sun, L.; Jiang, S.; Marciante, J.R.

    2010-06-22

    An all-fiber optical Faraday mirror that consists of a fiber Faraday rotator and a fiber Bragg grating is demonstrated. The fiber Faraday rotator uses a 21-cm-long section of 56-wt%-terbium-doped silicate fiber. The polarization state of the reflected light is rotated 89 degrees +/- 2 degrees with a 16-dB polarization extinction ratio.

  18. Fiber optic gyro development at Fibernetics

    NASA Astrophysics Data System (ADS)

    Bergh, Ralph A.; Arnesen, Leif; Herdman, Craig

    2016-05-01

    Fiber optic gyroscope based inertial sensors are being used within increasingly severe environments, enabling unmanned systems to sense and navigate in areas where GPS satellite navigation is unavailable or jammed. A need exists for smaller, lighter, lower power inertial sensors for the most demanding land, sea, air, and space applications. Fibernetics is developing a family of inertial sensor systems based on our closed-loop navigation-grade fiber optic gyroscope (FOG). We are making use of the packaging flexibility of the fiber to create a navigation grade inertial measurement unit (IMU) (3 gyroscopes and 3 accelerometers) that has a volume of 102 cubic inches. We are also planning a gyrocompass and an inertial navigation system (INS) having roughly the same size. In this paper we provide an update on our development progress and describe our modulation scheme for the Sagnac interferometers. We also present a novel multiplexed design that efficiently delivers source light to each of the three detectors. In our future development section we discuss our work to improve FOG performance per unit volume, specifically detailing our focus in utilizing a multicore optical fiber.

  19. Renewable Reagent Fiber Optic Based Ammonia Sensor

    NASA Astrophysics Data System (ADS)

    Berman, Richard J.; Burgess, Lloyd W.

    1990-02-01

    Many fiber optic based chemical sensors have been described which rely on a reagent chemistry fixed at the fiber endface to provide analyte specificity. In such systems, problems involving probe-to-probe reproducibility, reagent photolability and reagent leaching are frequently encountered. As a result, calibration and standardization of these sensors becomes difficult or impossible and thus inhibits their application for long term in situ chemical monitoring. Many of these problems can be addressed and several additional advantages gained by continuously renewing the reagent chemistry. To illustrate this concept, a fiber optic ammonia sensor is described in which the reagent is delivered under direct control to a sensing volume of approximately 400 nanoliters located at the probe tip. Using an acid-base indicator (bromothymol blue) as the reagent, the sample ammonia concentrations are related to modulations in light intensity with a lower limit of detection of 10 ppb. The sensor performance was studied with respect to reagent pH, concentration and reagent delivery rate. Compared with previous fiber optic ammonia sensors, the ability to reproducibly renew the reagent has resulted in improvements with respect to response and return times, probe-to-probe reproducibility, probe lifetime and flexibility of use.

  20. Development Of Porous Glass Fiber Optic Sensors

    NASA Astrophysics Data System (ADS)

    Macedo, P. B.; Barkatt, Aa.; Feng, X.; Finger, S. M.; Hojaji, H.; Laberge, N.; Mohr, R.; Penafiel, M.; Saad, E.

    A method for producing rugged, continuous porous glass fiber optic sensors was developed. pH and temperature sensors based on this technology have been successfully produced. The sensor portion of the fiber is made porous by selective leaching of a specially formulated borosilicate glass fiber. This results in a strong, monolithic structure where the sensor portion of the fiber remains integrally attached to the rest of the fiber (which acts as a light pipe), essentially eliminating losses at the sensor-light pipe interface. Pore size in the sensor can be controllably varied by modifying heat treatment conditions, making these sensors suitable for chemical concentration measurements in liquids and gases. Appropriate dyes were chemically bonded by silanization to the large interior surface area of the porous sensors to produce the pH and temperature sensors. Cresol red and phenol red were used for pH and pinacyanol chloride was used for temperature sensing. The sensitivity of these devices can be controlled by varying the concentration of the chemically bonded dye and the length of the porous region. Optical absorbance measurements were made in the visible range. The tip of the sensors was coated with a thin, porous layer of gold to reflect the incident light, resulting in a double pass across the porous sensor. Experimental measurements were made over a pH range of 3 to 8 and a temperature range of 28-70 C. These porous glass fiber optic sensors were found to be rugged and reliable due to their monolithic structure and large interior surface area for attachment of active species. A broad range of sensors based on this technology could be developed by using different active species, such as enzymes and other biochemicals, which could be bonded to the interior surface of the porous glass sensor.