WorldWideScience

Sample records for optical chemical sensors

  1. Wearable Optical Chemical Sensors

    Science.gov (United States)

    Lobnik, Aleksandra

    Wearable sensors can be used to provide valuable information about the wearer's health and/or monitor the wearer's surroundings, identify safety concerns and detect threats, during the wearer's daily routine within his or her natural environment. The "sensor on a textile", an integrated sensor capable of analyzing data, would enable early many forms of detection. Moreover, a sensor connected with a smart delivery system could simultaneously provide comfort and monitoring (for safety and/or health), non-invasive measurements, no laboratory sampling, continuous monitoring during the daily activity of the person, and possible multi-parameter analysis and monitoring. However, in order for the technology to be accessible, it must remain innocuous and impose a minimal intrusion on the daily activities of the wearer. Therefore, such wearable technologies should be soft, flexible, and washable in order to meet the expectations of normal clothing. Optical chemical sensors (OCSs) could be used as wearable technology since they can be embedded into textile structures by using conventional dyeing, printing processes and coatings, while fiber-optic chemical sensors (FOCSs) as well as nanofiber sensors (NFSs) can be incorporated by weaving, knitting or laminating. The interest in small, robust and sensitive sensors that can be embedded into textile structures is increasing and the research activity on this topic is an important issue.

  2. Fiber Optic Chemical Sensors

    Science.gov (United States)

    1993-10-01

    Studies Press Ltd, Book Chapter, AIS, 1-25, 1983. Saarl, Linda A. and Seltz, Rudolf W., "Immobilized Morin as Fluorescence Sensor for Determination...34Thin Films," Photonics Spectra, AVO, AIS, 113-118, 1988. Hanst, Philip L. and Stephens, Edgar R., "Infrared Analysis of Engine Exhausts: Methyl...79-84, 1988. Watson, Jr., Edgar , "On-line Analysis of Trace Contaminants 145 36 in Process Streams," Amarican Laboratory, AVO, AIS, 97-101, 1988

  3. Integrated optical sensors for the chemical domain

    NARCIS (Netherlands)

    Lambeck, Paul V.

    2006-01-01

    During the last decade there has been a rapidly growing interest in integrated optical (IO) sensors, expecially because many of them principally allow for sensitive, real time, label-free-on-site measurements of the concentration of (bio-)chemical species. This review aims at giving an overview of t

  4. Integrated optical sensors for the chemical domain

    NARCIS (Netherlands)

    Lambeck, Paul

    2006-01-01

    During the last decade there has been a rapidly growing interest in integrated optical (IO) sensors, expecially because many of them principally allow for sensitive, real time, label-free-on-site measurements of the concentration of (bio-)chemical species. This review aims at giving an overview of t

  5. Waveguide-based optical chemical sensor

    Science.gov (United States)

    Grace, Karen M.; Swanson, Basil I.; Honkanen, Seppo

    2007-03-13

    The invention provides an apparatus and method for highly selective and sensitive chemical sensing. Two modes of laser light are transmitted through a waveguide, refracted by a thin film host reagent coating on the waveguide, and analyzed in a phase sensitive detector for changes in effective refractive index. Sensor specificity is based on the particular species selective thin films of host reagents which are attached to the surface of the planar optical waveguide. The thin film of host reagents refracts laser light at different refractive indices according to what species are forming inclusion complexes with the host reagents.

  6. Flexible optical chemical sensor platform for BTX

    OpenAIRE

    Arias Espinoza, Juan Diego; Sazhnikov, Viacheslav; Sabik, Sami; Ionov, Dmitriy; Smits, Edsger; Kalathimekkad, Sandeep; Van Steenberge, Geert; Alfimov, Michail; Posniak, Malgorzata; Schoo, Herman

    2012-01-01

    An in-plane flexible sensor platform for BTX detection was developed using low-cost patterning techniques and foil-based optical components. The platform was produced by a combination of laser patterning, inkjet printing and capillary filling. Key optical components such as lightguides, opticalcladding layers and metallic interconnections were realized on low cost substrates such as paper and PET. The sensing mechanism is based on the change in fluorescence spectra of a reporter dye, supporte...

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

    Directory of Open Access Journals (Sweden)

    Marie Pospíšilová

    2015-09-01

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

  8. Optical chemical and biochemical sensors: new trends (Invited Paper)

    Science.gov (United States)

    Baldini, F.; Giannetti, A.

    2005-06-01

    Chemical and biochemical sensing is under the extensive research all over the world and many chemical and biochemical sensors are finding increasing number of applications in industry, environmental monitoring, medicine, biomedicine and chemical analysis. This is evidenced by each-year-growing number of international scientific conferences, in which advances in the field of the sensors are reported. One of the main reason why only a few sensors reach the international market, notwithstanding the high number of laboratory prototype described in many peer reviewed papers, lies in the fact that a biochemical sensor is a highly interdisciplinary "object" the realization of which requires the team work of scientists coming from different areas such as chemistry, physics, optoelectronics, engineering, biochemistry, and medicine. And this peculiarity is not easily found in the research teams. In the present paper, the fundamental bases of chemical and biochemical optical sensing are summarised and the new trends are described.

  9. Development of an optical redox chemical sensor for nitrite determination

    Directory of Open Access Journals (Sweden)

    Saadat Rastegarzadeh

    2012-01-01

    Full Text Available An optical chemical sensor for the determination of nitrite based on incorporating methyltrioctylammonium chloride as an anionic exchanger on the triacetylcellulose polymer has been reported. The response of the sensor is based on the redox reaction between nitrite in aqueous solution and iodide adsorbed on sensing membrane using anion exchange phenomena. The sensing membrane reversibly responses to nitrite ion over the range of 6.52×10-6 - 8.70×10-5 mol L-1 with a detection limit of 6.05×10-7 mol L-1 (0.03 µg mL-1 and response time of 6 min. The relative standard deviation for eight replicate measurements of 8.70×10-6 and 4.34×10-5 mol L-1 of nitrite was 4.4 and 2.5 %, respectively. The sensor was successfully applied for determination of nitrite in food, saliva and water samples.

  10. Tapered optical fiber sensor for chemical pollutants detection in seawater

    Science.gov (United States)

    Irigoyen, Maite; Sánchez-Martin, Jose Antonio; Bernabeu, Eusebio; Zamora, Alba

    2017-04-01

    Three tapered silica optical fibers, uncoated and coated with metallic (Al or Cu) and dielectric layers (TiO2), are employed to determine the presence of oil and Hazardous and Noxious Substances (HNS from now on) in water, by means of the measurement of their spectral transmittance. With our experimental assembly, the presence of oil and HNS spills can be detected employing the three different kinds of tapers, since the complete range of refractive indices of the pollutants (1.329-1.501) is covered with these tapers. The most suitable spectral range to detect the presence of a chemical pollutant in seawater has been identified and a complete spectral characterization of the three types of optical fiber tapers has been carried out. The results obtained show that, in general terms, these devices working together can be employed for the early detection of oil and HNS spills in seawater in a marine industrial environment. These sensors have many advantages, such as its low cost, its simplicity and versatility (with interesting properties as quick response and repeatability), and especially that they can be self-cleaned with seawater in motion.

  11. Direct-Dispense Polymeric Waveguides Platform for Optical Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Mohamad Hajj-Hassan

    2008-12-01

    Full Text Available We describe an automated robotic technique called direct-dispense to fabricate a polymeric platform that supports optical sensor arrays. Direct-dispense, which is a type of the emerging direct-write microfabrication techniques, uses fugitive organic inks in combination with cross-linkable polymers to create microfluidic channels and other microstructures. Specifically, we describe an application of direct-dispensing to develop optical biochemical sensors by fabricating planar ridge waveguides that support sol-gelderived xerogel-based thin films. The xerogel-based sensor materials act as host media to house luminophore biochemical recognition elements. As a prototype implementation, we demonstrate gaseous oxygen (O2 responsive optical sensors that operate on the basis of monitoring luminescence intensity signals. The optical sensor employs a Light Emitting Diode (LED excitation source and a standard silicon photodiode as the detector. The sensor operates over the full scale (0%-100% of O2 concentrations with a response time of less than 1 second. This work has implications for the development of miniaturized multisensor platforms that can be cost-effectively and reliably mass-produced.

  12. Improved fiber-optic chemical sensor for penicillin

    Energy Technology Data Exchange (ETDEWEB)

    Healy, B.G.; Walt, D.R. [Tufts Univ., Medford, MA (United States)

    1995-12-15

    An optical penicillin biosensor is described, based on the enzyme penicillinase. The sensor is fabricated by selective photodeposition of analyte-sensitive polymer matrices on optical imaging fibers. The penicillin-sensitive matrices are fabricated by immobilizing the enzyme as micrometer-sized particles in a polymer hydrogel with a covalently bound pH indicator. An array of penicillin-sensitive and pH-sensitive matrices are fabricated on the same fiber. This array allows for the simultaneous, independent measurement of pH and penicillin. Independent measurement of the two analytes allows penicillin to be quantitated in the presence of a concurrent pH change. An analysis was conducted of enzyme kinetic parameters in order to model the penicillin response of the sensor at all pH values. This analysis accounts for the varying activity of the immobilized penicillinase at different pH values. The sensor detects penicillin in the range 0.25-10.0 mM in the pH range 6.2-7.5. The sensor was used to quantify penicillin concentration produced during a Penicillium chrysogenum fermentation. 27 refs., 7 figs., 1 tab.

  13. Chemical sensors

    Science.gov (United States)

    Lowell, J.R. Jr.; Edlund, D.J.; Friesen, D.T.; Rayfield, G.W.

    1991-07-02

    Sensors responsive to small changes in the concentration of chemical species are disclosed. The sensors comprise a mechanochemically responsive polymeric film capable of expansion or contraction in response to a change in its chemical environment. They are operatively coupled to a transducer capable of directly converting the expansion or contraction to a measurable electrical response. 9 figures.

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

    Science.gov (United States)

    Ferguson, Jane A.

    2001-06-01

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

  15. Feasibility of a Stack Integrated SOFC Optical Chemical Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Michael A. Carpenter

    2007-09-30

    The DOE-NETL Innovative Concepts (IC) phase II program investigated the feasibility of harsh environment compatible chemical sensors based on monitoring the surface plasmon resonance (SPR) bands of metal nanoparticle doped YSZ nano-cermets, as a function of fuel concentrations, impurities e.g. CO and temperature(500-900 C). In particular, Au nanoparticles (AuNPs) exhibit a strong surface plasmon resonance (SPR) band whose shape and spectral position is not only highly dependent on the refractive index of the host medium but also on chemical reactions at the interface between the metal and the surrounding environment. Studies have been completed on the oxygen and temperature dependence of the SPR band of the AuNPs, CO sensing studies, oxygen/hydrogen titration experiments, ethanol sensing studies and finally NO{sub 2} sensing studies. Reversible changes in the SPR band are observed for all chemical exposure studies with the sensing mechanism being determined by the oxidative or reductive properties of the exposure gases. Reactions which remove charge from the AuNPs was observed to cause a redshift in the SPR band, while charge donation to the AuNPs causes a blue shift in the SPR band. CO, hydrogen and ethanol in air mixtures were all reductive in nature as they reacted with the YSZ bound oxygen anions forming CO{sub 2} or H{sub 2}O thus ultimately inducing charge donation to the AuNPs and a blue shift in the SPR band. While NO{sub 2} and oxygen were oxidative and induced the production of YSZ bound oxygen anions, charge removal from the AuNPs and a redshift in the SPR band.

  16. Temperature-Insensitive Chemical Sensor with Twin Bragg Gratings in an Optical Fibre

    Institute of Scientific and Technical Information of China (English)

    SANG Xin-Zhu; YU Chong-Xiu; YAN Bin-Bin; MA Jian-Xin; MENG Zhao-Fang; Mayteevarunyoo T.; LU Nai-Guang

    2006-01-01

    To reduce temperature sensitivity of the fibre Bragg grating (FBG) chemical sensor, a simple method is proposed by measuring the peak wavelength difference between an etched FBG and an un-etched one in an optical fibre.Thermal characteristics and chemical sensitivity of the sensor are experimentally investigated. The experimental results indicate that the etched FBG and the rest one have almost the same thermal response, and concentration changes of the surrounding chemical solutions can be detected by measuring the peak wavelength difference between them. The sensor has been used to measure the concentrations of propylene glycol solutions and sugar solutions, and it could detect 0.7% and 0.45% concentration changes for them with an optical spectrum analyser in resolution of 10pm.

  17. Integrated optical sensors for 2D spatial chemical mapping (Conference Presentation)

    Science.gov (United States)

    Flores, Raquel; Janeiro, Ricardo; Viegas, Jaime

    2017-02-01

    Sensors based on optical waveguides for chemical sensing have attracted increasing interest over the last two decades, fueled by potential applications in commercial lab-on-a-chip devices for medical and food safety industries. Even though the early studies were oriented for single-point detection, progress in device size reduction and device yield afforded by photonics foundries have opened the opportunity for distributed dynamic chemical sensing at the microscale. This will allow researchers to follow the dynamics of chemical species in field of microbiology, and microchemistry, with a complementary method to current technologies based on microfluorescence and hyperspectral imaging. The study of the chemical dynamics at the surface of photoelectrodes in water splitting cells are a good candidate to benefit from such optochemical sensing devices that includes a photonic integrated circuit (PIC) with multiple sensors for real-time detection and spatial mapping of chemical species. In this project, we present experimental results on a prototype integrated optical system for chemical mapping based on the interaction of cascaded resonant optical devices, spatially covered with chemically sensitive polymers and plasmon-enhanced nanostructured metal/metal-oxide claddings offering chemical selectivity in a pixelated surface. In order to achieve a compact footprint, the prototype is based in a silicon photonics platform. A discussion on the relative merits of a photonic platform based on large bandgap metal oxides and nitrides which have higher chemical resistance than silicon is also presented.

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

    Science.gov (United States)

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

    2004-03-01

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

  19. Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

    Directory of Open Access Journals (Sweden)

    Fuensanta Sánchez Rojas

    2006-10-01

    Full Text Available Optical techniques for chemical analysis are well established and sensors based on thesetechniques are now attracting considerable attention because of their importance in applications suchas environmental monitoring, biomedical sensing, and industrial process control. On the other hand,flow injection analysis (FIA is advisable for the rapid analysis of microliter volume samples and canbe interfaced directly to the chemical process. The FIA has become a widespread automatic analyticalmethod for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, andease of assembling. In this paper, an overview of flow injection determinations by using opticalchemical sensors is provided, and instrumentation, sensor design, and applications are discussed. Thiswork summarizes the most relevant manuscripts from 1980 to date referred to analysis using opticalchemical sensors in FIA.

  20. Towards a new generation of fibre optic chemical sensors based on spider silk threads

    Science.gov (United States)

    Hey Tow, Kenny; Chow, Desmond M.; Vollrath, Fritz; Dicaire, Isabelle; Gheysens, Tom; Thévenaz, Luc

    2017-04-01

    A spider uses up to seven different types of silk, all having specific functions, to build its web. For scientists, native silk - directly extracted from spiders - is a tough, biodegradable and biocompatible thread used mainly for tissue engineering and textile applications. Blessed with outstanding optical properties, this protein strand can also be used as an optical fibre and is, moreover, intrinsically sensitive to chemical compounds. In this communication, a pioneering proof-of-concept experiment using spider silk, in its pristine condition, as a new type of fibre-optic relative humidity sensor will be demonstrated and its potential for future applications discussed.

  1. Surface plasmon resonance based fibre optic chemical sensor for the detection of cocaine

    Science.gov (United States)

    Nguyen, T. Hien; Sun, Tong; Grattan, Kenneth T. V.

    2016-05-01

    A surface plasmon based fibre-optic chemical sensor for the detection of cocaine has been developed using a molecularly imprinted polymer (MIP) film with embedded gold nanoparticles as the recognition element. The MIP was formed on the layer of gold thin film which was deposited on the surface of a fibre core. The sensing was based on swelling of the MIP film induced by analyte binding that shifted the resonance spectrum toward a shorter wavelength. The sensor exhibited a response to cocaine in the concentration range of 0 - 400 μM in aqueous acetonitrile mixtures. Selectivity for cocaine over other drugs has also been demonstrated.

  2. Chemically robust platform for optical solid-state conducting polymer sensor

    Science.gov (United States)

    Holt, A. L.; Bearinger, J. P.; Carter, S. A.

    2006-10-01

    Conjugated polymers are unique materials for use in the development of chemical and biological sensors because of their widely tunable optical and electrical properties that allow them dual functionality as both the sensing element and the signal transducer. Furthermore, as optical photoluminescence based sensors, electroactive polymers are found to exhibit high sensitivity due to the ability of the analyte of interest to quench the photoluminescence of the entire polymer chain. In order to produce a more chemically robust thin film for use as a "solid-state" optical sensor, we succeeded in grafting various poly (3-alkyl-thiophene)s to optically transparent substrates such as glass, quartz, and ITO coated glass. This was accomplished by first grafting a thiophene monomer to the surface then chemically growing the films via oxidative polymerization. XPS studies indicated that each chemical step was accurately understood. The polythiophene growth, unaltered by sonication and tape peeling tests, was uniform across the substrate and could be directed by selective silanization of the substrate. Film thicknesses range from 20 to 200 nm and exhibit varying degrees of surface roughness, depending on the polymerization process. The reaction times and solvents were varied in order to optimize the desired film properties. The absorption and photoluminescence properties of the thin films compared well with literature on spun-cast polythiophene films, as did the electrical conductivities of the doped and undoped material. The photoluminescence intensities of the films are found to be unaffected by paraquat in water but are sensitive to trace amounts of ferric chloride in acetonitrile with measurable Stern Volmer constants.

  3. Fiber Bragg distributed chemical sensor

    NARCIS (Netherlands)

    Boersma, A.; Cheng, L.K.; Jansen, T.H.

    2010-01-01

    A distributed chemical sensor is developed by coating multiple Bragg gratings in a fibre with chemical selective responsive coatings. The optical response of the coated grating is optimised and the recoat process is very reproducible.

  4. Nanostructured Fiber Optic Cantilever Arrays and Hybrid MEMS Sensors for Chemical and Biological Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advancements in nano-/micro-scale sensor fabrication and molecular recognition surfaces offer promising opportunities to develop miniaturized hybrid fiber optic and...

  5. Roadmap on optical sensors

    Science.gov (United States)

    Ferreira, Mário F. S.; Castro-Camus, Enrique; Ottaway, David J.; López-Higuera, José Miguel; Feng, Xian; Jin, Wei; Jeong, Yoonchan; Picqué, Nathalie; Tong, Limin; Reinhard, Björn M.; Pellegrino, Paul M.; Méndez, Alexis; Diem, Max; Vollmer, Frank; Quan, Qimin

    2017-08-01

    conventional, specialty and photonic crystal fibers. Several other sections are dedicated to micro- and nano-engineered sensors, including whispering-gallery mode and plasmonic sensors. The uses of optical sensors in chemical, biological and biomedical areas are described in other sections. Different approaches required to satisfy applications at visible, infrared and THz spectral regions are also discussed. Advances in science and technology required to meet challenges faced in each of these areas are addressed, together with suggestions on how the field could evolve in the near future.

  6. Characterization and application of PBA fiber optic chemical film sensor based on fluorescence multiple quenching

    Institute of Scientific and Technical Information of China (English)

    陈坚; 李伟; 阎超; 袁立懋; 郭炬亮; 周新继

    1997-01-01

    The three types of structure of the pyrenebutyric acid of fiber optic chemical film sensor were stud-ied by fluorescence multiple quenching. They are, for different test samples and purposes, respectively general, three-way and combined. A tri-cup method was designed to demonstrate the multiple quenching of response mechanism, and a relationship formula of mathematical approach was established. The response mechanism was shown to include the dynamic quenching , inner-filter effects and/or resonance energy transfer. To show the response characterization in a series of organic and inorganic quenchers, a new concept of apparent quenching coefficient Kq was advanced. This kind of sensor has been used in continuous and in situ monitoring of the dissolution rate of drug tablets, on line and in situ monitoring of some organic therapeutic drugs in biological fluid and Cr( VI ) in industrial waste water. The measured data were examined and compared with HPLC or HPTLCS. Test results show that the sensors and appa

  7. Thermal and chemical treatment of polymer optical fiber Bragg grating sensors for enhanced mechanical sensitivity

    DEFF Research Database (Denmark)

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

    2017-01-01

    An investigation of the thermal annealing effects on the strain, stress, and force sensitivities of polymer optical fiber Bragg grating sensors is performed. We demonstrate for the first time that the fiber annealing can enhance both stress and force sensitivities of Bragg grating sensors, with t...

  8. Integrated Optical Sensors

    NARCIS (Netherlands)

    Lambeck, Paul; Hoekstra, Hugo

    2003-01-01

    The optical (tele-) communication is the main driving force for the worldwide R&D on integrated optical devices and microsystems. lO-sensors have to compete with many other sensor types both within the optical domain (fiber sensors) and outside that domain, where sensors based on measurand induced c

  9. Integrated Optical Sensors

    NARCIS (Netherlands)

    Lambeck, Paul V.; Hoekstra, Hugo

    2003-01-01

    The optical (tele-) communication is the main driving force for the worldwide R&D on integrated optical devices and microsystems. lO-sensors have to compete with many other sensor types both within the optical domain (fiber sensors) and outside that domain, where sensors based on measurand induced c

  10. Errors in Chemical Sensor Measurements

    Directory of Open Access Journals (Sweden)

    Artur Dybko

    2001-06-01

    Full Text Available Various types of errors during the measurements of ion-selective electrodes, ionsensitive field effect transistors, and fibre optic chemical sensors are described. The errors were divided according to their nature and place of origin into chemical, instrumental and non-chemical. The influence of interfering ions, leakage of the membrane components, liquid junction potential as well as sensor wiring, ambient light and temperature is presented.

  11. Fiber Bragg distributed chemical sensor

    NARCIS (Netherlands)

    Boersma, A.; Saalmink, M.; Lucassen, T.; Wiegersma, S.; Jansen, T.H.; Jansen, R.; Cheng, L.K.

    2011-01-01

    A distributed chemical sensor is developed by coating multiple Bragg gratings in a single glass fiber with chemical responsive coatings. The composition of the coating is tuned to the target chemicals to be measured and the optical response of the coated grating is optimized by changing the coating

  12. Integrated optic chemical sensor for the simultaneous detection and quantification of multiple ions. Final report, March--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, E.

    1995-09-01

    This final report summarizes the work performed by Physical Optics Corporation (POC) on the DOE contract entitled {open_quotes}Integrated Optic Chemical Sensor for the Simultaneous Detection and Quantification of Multiple Metal Ions{close_quotes}. This project successfully demonstrated a multi-element integrated optic chemical sensor (IOCS) system capable of simultaneous detection and quantification of metal ions in a water flow stream. POC`s innovative integrated optic chemical sensor technology uses an array of chemically active optical waveguides integrated in parallel in a single small IOCS chip. The IOCS technique uses commonly available materials and straightforward processing to produce channel waveguides in porous glass, each channel treated with a chemical indicator that responds optically to heavy metal ions in a water flow stream. The porosity of the glass allows metal ions present in the water to diffuse into the glass and interact with the immobilized indicators, producing a measurable optical chance. For the {open_quotes}proof-of-concept{close_quotes} demonstration, POC designed and fabricated two types of IOCS chips. Type I uses an array of four straight channel waveguides, three of which are doped with a metal sensitive indicator, an ionophore. The undoped fourth channel is used as the reference channel. Type II uses a 1 x 4 star coupler structure with three sensing channels and a reference channel. Successful implementation of the IOCS technology is expected to have a broad impact on water quality control as well as in the commercial environmental monitoring market. Because of the self-referenced, multidetection capability of the IOCS technique, POC`s water quality sensors are expected to find markets in environmental monitoring and protection, ground water monitoring, and in-line process control. Specific applications include monitoring of chromium, copper, and iron ions in water discharged by the metal plating industry.

  13. Intrinsic Fiber Optic Chemical Sensors for Subsurface Detection of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Jesus [Intelligent Optical Systems, Inc., Torrance, CA (United States)

    2016-01-01

    Intelligent Optical Systems, Inc. has developed distributed intrinsic fiber optic sensors to directly quantify the concentration of dissolved or gas-phase CO2 for leak detection or plume migration in carbon capture and sequestration (CCS). The capability of the sensor for highly sensitive detection of CO2 in the pressure and temperature range of 15 to 2,000 psi and 25°C to 175°C was demonstrated, as was the capability of operating in highly corrosive and contaminated environments such as those often found in CO2 injection sites. The novel sensor system was for the first time demonstrated deployed in a deep well, detecting multiple CO2 releases, in real time, at varying depths. Early CO2 release detection, by means of a sensor cable integrating multiple sensor segments, was demonstrated, as was the capability of quantifying the leak. The novel fiber optic sensor system exhibits capabilities not achieved by any other monitoring technology. This project represents a breakthrough in monitoring capabilities for CCS applications.

  14. Integrated opto-chemical sensors

    NARCIS (Netherlands)

    Lambeck, Paul V.

    1992-01-01

    Integrated opto-chemical sensors have promising prospects, for example by having the potential to be realized as very sensitive small monolithic smart multisensor systems with a digital signal output. Here the main accent will be laid on the optical principles underlying chemo-optical waveguiding se

  15. Capacitive chemical sensor

    Science.gov (United States)

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  16. MEMS optical sensor

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an all-optical sensor utilizing effective index modulation of a waveguide and detection of a wavelength shift of reflected light and a force sensing system accommodating said optical sensor. One embodiment of the invention relates to a sensor system comprising...... at least one multimode light source, one or more optical sensors comprising a multimode sensor optical waveguide accommodating a distributed Bragg reflector, at least one transmitting optical waveguide for guiding light from said at least one light source to said one or more multimode sensor optical...... waveguides, a detector for measuring light reflected from said Bragg reflector in said one or more multimode sensor optical waveguides, and a data processor adapted for analyzing variations in the Bragg wavelength of at least one higher order mode of the reflected light....

  17. Chemical gas sensor application of open-pore mesoporous thin films based on integrated optical polarimetric interferometry.

    Science.gov (United States)

    Qi, Zhi-Mei; Honma, Itaru; Zhou, Haoshen

    2006-02-15

    Chemical gas sensors that employ integrated optical polarimetric interferometry were fabricated by the sol-gel synthesis of transparent mesoporous thin films of TiO2-P2O5 nanocomposite on tapered layers of TiO2 sputtered on tin-diffused glass waveguides. Atomic force microscopy images of the mesoporous thin film clearly show the open pore mouths on the film surface that favor rapid diffusion and adsorption of gas-phase analytes within the entire film. Adsorption of gas and vapor induces changes (Deltan) in the refractive index of the mesoporous thin film that lead to shifts in the phase difference between the fundamental transverse electric and magnetic modes simultaneously excited in the glass waveguide via single-beam incidence. Upon exposure to NH3 gas at concentrations as low as 100 ppb in dry air at room temperature, the sensor exhibits a reversible change in the phase difference with the response and recovery times of less than 60 and 90 s, respectively. It is unexpected that the sensor is unresponsive to either NO2 or C6H6 vapor, leading to a somewhat selective sensitivity to NH3. Determination of Deltan was carried out with a combination of the experimental results and the theoretical calculations. The sensor design represents a novel, effective, and easily accessible approach to mesoporous thin-film-based integrated optical chemical sensors.

  18. Infrared Fiber Optic Sensors

    Science.gov (United States)

    1997-01-01

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

  19. Sol-gels with fiber-optic chemical sensor potential: Effects of preparation, aging, and long-term storage

    Science.gov (United States)

    Badini, G. E.; Grattan, K. T. V.; Tseung, A. C. C.

    1995-08-01

    The features of sol-gels, incorporating pH-sensitive dyes, designed as potential substrates for fiber-optic chemical sensors, have been investigated in terms of a variety of characteristics resulting from the preparation methods used and following the storage of samples for a period of several years. These materials, organically doped sol-gels, have been used as the heart of a number of prototype chemical sensing instruments, and a key issue in their effective use in instrumentation is their long-term durability and stability. In this work, it has been shown that such aged gel substrates can withstand immersion in water, drying, and reimmersion without fragmenting. Such impregnated gels were shown to still exhibit strong fluorescence, although some changes to the gel structure, determined from microhardness measurements, were observed and reported, reflecting their potential for use in chemically sensitive fiber optic-based instruments.

  20. Optical fiber chemical sensors with sol-gel derived nanomaterials for monitoring high temperature/high pressure reactions in clean energy technologies

    Science.gov (United States)

    Tao, Shiquan

    2010-04-01

    The development of sensor technologies for in situ, real time monitoring the high temperature/high pressure (HTP) chemical processes used in clean energy technologies is a tough challenge, due to the HTP, high dust and corrosive chemical environment of the reaction systems. A silica optical fiber is corrosive resistance, and can work in HTP conditions. This paper presents our effort in developing fiber optic sensors for in situ, real time monitoring the concentration of trace ammonia and hydrogen in high temperature gas samples. Preliminary test results illustrate the feasibility of using fiber optic sensor technologies for monitoring HTP processes for next generation energy industry.

  1. Chemical detection in liquid media with a refractometric sensor based on a multimode optical fibre

    OpenAIRE

    V. Matejec; Jaffrezic-Renault, N.; Abdelghani, A.; S. Hleli; Cherif, K

    2002-01-01

    In this paper the physical basis for the design of an optical fibre sensor suited for aqueous medium and gas phase based on the excitation of an evanescent wave at the core/cladding interface is developed. The detection based on the refractive index changes (between 1.41 and 1.45) of the infinite dielectric medium which can be an electrolyte or a sol-gel polymer deposited on the uncladed part of the fibre. Refractive indices of absorbent and volatile compounds such as fuel and unleaded gas we...

  2. Optical waveguide sensors

    NARCIS (Netherlands)

    Fluitman, J.; Popma, Th.

    1986-01-01

    An overview of the field of optical waveguide sensors is presented. Some emphasis is laid on the development of a single scheme under which the diversity of sensor principles can be arranged. First three types of sensors are distinguished: intrinsic, extrinsic and active. Next, two steps are disting

  3. MEMS optical sensor

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an all-optical sensor utilizing effective index modulation of a waveguide and detection of a wavelength shift of reflected light and a force sensing system accommodating said optical sensor. One embodiment of the invention relates to a sensor system comprising...... waveguides, a detector for measuring light reflected from said Bragg reflector in said one or more multimode sensor optical waveguides, and a data processor adapted for analyzing variations in the Bragg wavelength of at least one higher order mode of the reflected light....

  4. Chemical detection in liquid media with a refractometric sensor based on a multimode optical fibre

    Directory of Open Access Journals (Sweden)

    V. Matejec

    2002-06-01

    Full Text Available In this paper the physical basis for the design of an optical fibre sensor suited for aqueous medium and gas phase based on the excitation of an evanescent wave at the core/cladding interface is developed. The detection based on the refractive index changes (between 1.41 and 1.45 of the infinite dielectric medium which can be an electrolyte or a sol-gel polymer deposited on the uncladed part of the fibre. Refractive indices of absorbent and volatile compounds such as fuel and unleaded gas were determined. Using a xerogel sensing layer as optical cladding, toluene detection in water was performed. The observed sensitivity is linear and the detection limit is 1% (in volume toluene in water.

  5. Fabrication of optical chemical ammonia sensors using anodized alumina supports and sol-gel method.

    Science.gov (United States)

    Markovics, Akos; Kovács, Barna

    2013-05-15

    In this comparative study, the fabrication and the sensing properties of various reflectometric optical ammonia gas sensors are described. In the first set of experiments the role of the support material was investigated on four different sensor membranes. Two of them were prepared by the adsorption of bromocresol green indicator on anodized aluminum plates. The applied anodizing voltages were 12 V and 24 V, which resulted in different dynamic ranges and response times for gaseous ammonia. The sol-gel method was used for the preparation of the other batch of sensors. These layers were coated on anodized aluminum plates (24 V) and on standard microscope cover glasses. In spite of the identical sensing chemistry, slightly different response times were measured merely because of the aluminum surface porosity. Gas molecules can remain entrapped in the pores, which results in delayed recovery time. On the other hand, the porous oxide film provides excellent adhesion, making the anodized aluminum an attractive support for the sol-gel layer.

  6. Fiber optic geophysical sensors

    Science.gov (United States)

    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.

  7. An optical chemical sensor for thorium (IV) determination based on thorin.

    Science.gov (United States)

    Rastegarzadeh, S; Pourreza, N; Saeedi, I

    2010-01-15

    A selective method for the determination of thorium (IV) using an optical sensor is described. The sensing membrane is prepared by immobilization of thorin-methyltrioctylammonium ion pair on triacetylcellulose polymer. The sensor produced a linear response for thorium (IV) concentration in the range of 6.46 x 10(-6) to 9.91 x 10(-5)mol L(-1) with detection limit of 1.85 x 10(-6)mol L(-1). The regeneration of optode was accomplished completely at a short time (less than 20s) with 0.1 mol L(-1) of oxalate ion solution. The relative standard deviation for ten replicate measurements of 2.15 x 10(-5) and 8.62 x 10(-5)mol L(-1) of thorium was 2.71 and 1.65%, respectively. The optode membrane exhibits good selectivity for thorium (IV) over several other ionic species and are comparable to those obtained in case of spectrophotometric determination of thorium using thorin in solution. A good agreement with the ICP-MS and spiked method was achieved when the proposed optode was applied to the determination of thorium (IV) in dust and water samples.

  8. Submicrometer fiber-optic chemical sensors: Measuring pH inside single cells. Progress report, October 1990--August 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kopelman, R.

    1993-12-01

    Starting from scratch, we went in two and a half years to 0.04 micron optical microscopy resolution. We have demonstrated the application of near-field scanning optical microscopy to DNA samples and opened the new fields of near-field scanning spectroscopy and submicron opto- chemical sensors. All of these developments have been important steps towards in-situ DNA imaging and characterization on the nanoscale. Our first goal was to make NSOM (near-field scanning optical microscopy) a working enterprise, capable of ``zooming-in`` towards a sample and imaging with a resolution exceeding that of traditional microscopy by a factor of ten. This has been achieved. Not only do we have a resolution of about 40 nm but we can image a 1 {times} 1 micron object in less than 10 seconds. Furthermore, the NSOM is a practical instrument. The tips survive for days or weeks of scanning and new methods of force feedback will soon protect the most fragile samples. Reproducible images of metal gratings, gold particles, dye balls (for calibration) and of several DNA samples have been made, proving the practicality of our approach. We also give highly resolved Force/NSOM images of human blood cells. Our second goal has been to form molecular optics (e.g., exciton donor) tips with a resolution of 2--10 nm for molecular excitation microscopy (MEM). We have produced such tips, and scanned with them, but only with a resolution comparable to that of our standard NSOM tips. However, we have demonstrated their potential for high resolution imaging capabilities: (1) An energy transfer (tip to sample) based feedback capability. (2) A Kasha (external heavy atom) effect based feedback. In addition, a novel and practical opto-chemical sensor that is a billion times smaller than the best ones available has been developed as well. Finally, we have also performed spatially resolved fluorescence spectroscopy.

  9. Preparation,inentification and application of pyrenebutyric acid-silica and diphenylanthracene-silica reagent on fiber-optic chemical sensor

    Institute of Scientific and Technical Information of China (English)

    LI Xin-xia; CHEN Jian

    2003-01-01

    @@ 1 Introduction Two new fiber-optic chemical sensor based on multiple fluorescence quenching is described. The reagent phases of the sensors are stable in organic solvent. The first reagent phase was constructed by covalent bonding pyrenebutyric acid (PBA) to the surface of glass (PBA-SiO2). It was identified by IR spectrum, fluorescence spectra and TGA analysis. And it can determine Rutin in ethanol.

  10. Wearable Optical Sensors

    KAUST Repository

    Ballard, Zachary S.

    2017-07-12

    The market for wearable sensors is predicted to grow to $5.5 billion by 2025, impacting global health in unprecedented ways. Optics and photonics will play a key role in the future of these wearable technologies, enabling highly sensitive measurements of otherwise invisible information and parameters about our health and surrounding environment. Through the implementation of optical wearable technologies, such as heart rate, blood pressure, and glucose monitors, among others, individuals are becoming more empowered to generate a wealth of rich, multifaceted physiological and environmental data, making personalized medicine a reality. Furthermore, these technologies can also be implemented in hospitals, clinics, point-of-care offices, assisted living facilities or even in patients’ homes for real-time, remote patient monitoring, creating more expeditious as well as resource-efficient systems. Several key optical technologies make such sensors possible, including e.g., optical fiber textiles, colorimetric, plasmonic, and fluorometric sensors, as well as Organic Light Emitting Diode (OLED) and Organic Photo-Diode (OPD) technologies. These emerging technologies and platforms show great promise as basic sensing elements in future wearable devices and will be reviewed in this chapter along-side currently existing fully integrated wearable optical sensors.

  11. Fibre-optic sensors in health care

    Science.gov (United States)

    Grazia Mignani, Anna; Baldini, Francesco

    1997-05-01

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

  12. High-Temperature Optical Sensor

    Science.gov (United States)

    Adamovsky, Grigory; Juergens, Jeffrey R.; Varga, Donald J.; Floyd, Bertram M.

    2010-01-01

    A high-temperature optical sensor (see Figure 1) has been developed that can operate at temperatures up to 1,000 C. The sensor development process consists of two parts: packaging of a fiber Bragg grating into a housing that allows a more sturdy thermally stable device, and a technological process to which the device is subjected to in order to meet environmental requirements of several hundred C. This technology uses a newly discovered phenomenon of the formation of thermally stable secondary Bragg gratings in communication-grade fibers at high temperatures to construct robust, optical, high-temperature sensors. Testing and performance evaluation (see Figure 2) of packaged sensors demonstrated operability of the devices at 1,000 C for several hundred hours, and during numerous thermal cycling from 400 to 800 C with different heating rates. The technology significantly extends applicability of optical sensors to high-temperature environments including ground testing of engines, flight propulsion control, thermal protection monitoring of launch vehicles, etc. It may also find applications in such non-aerospace arenas as monitoring of nuclear reactors, furnaces, chemical processes, and other hightemperature environments where other measurement techniques are either unreliable, dangerous, undesirable, or unavailable.

  13. Optical sensor EIB/KNX gateway

    OpenAIRE

    Fernández Valdivielso, Carlos; Matías Maestro, Ignacio R.; Arregui-San-Martín, Francisco Javier; Jiménez Buendía, Manuel; Vera Repullo, José Alfonso; Roca Dorda, Joaquín

    2002-01-01

    Nowadays, there are some special building like for example power or chemical plants, where convetional electronic sensors cannot be used as they are exposed to explosive enviroments or due to the presence of either electromagnetic interferences, or chemical or mechanical disturbances. Because of that, those sensors cannot operate and monitor correctly the target parameters. In these cases, the use of optical fiber sensors is a valid alternative due to their passive nature, inmunity to electr...

  14. Miniature Chemical Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Andrew C. R. Pipino

    2004-12-13

    A new chemical detection technology has been realized that addresses DOE environmental management needs. The new technology is based on a variant of the sensitive optical absorption technique, cavity ring-down spectroscopy (CRDS). Termed evanescent-wave cavity ring-down spectroscopy (EW-CRDS), the technology employs a miniature solid-state optical resonator having an extremely high Q-factor as the sensing element, where the high-Q is achieved by using ultra-low-attenuation optical materials, ultra-smooth surfaces, and ultra-high reflectivity coatings, as well as low-diffraction-loss designs. At least one total-internal reflection (TIR) mirror is integral to the resonator permitting the concomitant evanescent wave to probe the ambient environment. Several prototypes have been designed, fabricated, characterized, and applied to chemical detection. Moreover, extensions of the sensing concept have been explored to enhance selectivity, sensitivity, and range of application. Operating primarily in the visible and near IR regions, the technology inherently enables remote detection by optical fiber. Producing 11 archival publications, 5 patents, 19 invited talks, 4 conference proceedings, a CRADA, and a patent-license agreement, the project has realized a new chemical detection technology providing >100 times more sensitivity than comparable technologies, while also providing practical advantages.

  15. Fiber Optic-Fluorescence Sensors for Remote Detection of Chemical Species in Seawater

    Science.gov (United States)

    1989-09-01

    from the viewing volume by diffusive/convective mass transport processes and replaced by uncomplexed indicator from the reservoir. Because the flow...Morin as Fluorescence sensor for Determination of Aluminum(III) ." Anal. Chem., 1983, 55, 667-670. (10) Urbano , E., H. Offenbacher, and O.S. Wolfbeis

  16. Optical fiber synaptic sensor

    Science.gov (United States)

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

    2011-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Shiquan Tao

    2006-12-31

    The chemistry of sol-gel derived silica and refractive metal oxide has been systematically studied. Sol-gel processes have been developed for preparing porous silica and semiconductor metal oxide materials. Micelle/reversed micelle techniques have been developed for preparing nanometer sized semiconductor metal oxides and noble metal particles. Techniques for doping metal ions, metal oxides and nanosized metal particles into porous sol-gel material have also been developed. Optical properties of sol-gel derived materials in ambient and high temperature gases have been studied by using fiber optic spectroscopic techniques, such as fiber optic ultraviolet/visible absorption spectrometry, fiber optic near infrared absorption spectrometry and fiber optic fluorescence spectrometry. Fiber optic spectrometric techniques have been developed for investigating the optical properties of these sol-gel derived materials prepared as porous optical fibers or as coatings on the surface of silica optical fibers. Optical and electron microscopic techniques have been used to observe the microstructure, such as pore size, pore shape, sensing agent distribution, of sol-gel derived material, as well as the size and morphology of nanometer metal particle doped in sol-gel derived porous silica, the nature of coating of sol-gel derived materials on silica optical fiber surface. In addition, the chemical reactions of metal ion, nanostructured semiconductor metal oxides and nanometer sized metal particles with gas components at room temperature and high temperatures have also been investigated with fiber optic spectrometric methods. Three classes of fiber optic sensors have been developed based on the thorough investigation of sol-gel chemistry and sol-gel derived materials. The first group of fiber optic sensors uses porous silica optical fibers doped with metal ions or metal oxide as transducers for sensing trace NH{sub 3} and H{sub 2}S in high temperature gas samples. The second group of

  18. Assessment of diffusion parameters of new passive samplers using optical chemical sensor for on-site measuring formaldehyde in indoor air: experimental and numerical studies.

    Science.gov (United States)

    Vignau-Laulhere, Jane; Mocho, Pierre; Plaisance, Hervé; Raulin, Katarzyna; Desauziers, Valérie

    2016-03-01

    New passive samplers using a sensor consisting of a sol-gel matrix entrapping Fluoral-P as sampling media were developed for the determination of formaldehyde in indoor air. The reaction between Fluoral-P and formaldehyde produces a colored compound which is quantified on-site by means of a simple optical reading module. The advantages of this sensor are selectivity, low cost, ppb level limit of detection, and on-site direct measurement. In the development process, it is necessary to determine the sampling rate, a key parameter that cannot be directly assessed in the case of diffusive samplers using optical chemical sensor. In this study, a methodology combining experimental tests and numerical modeling is proposed and applied at five different radial diffusive samplers equipped with the same optical chemical sensor to assess the sampled material flows and sampling rates. These radial diffusive samplers differ in the internal volume of the sampler (18.97 and 6.14 cm(3)), the position of sensor inside the sampler (in front and offset of 1.2 cm above the membrane) and the width of the diffusion slot (1.4 and 5.9 mm). The influences of these three parameters (internal volume, position of sensor inside the sampler, and width of the diffusion slot) were assessed and discussed with regard to the formaldehyde sampling rate and water uptake by sensor (potential interference of measure). Numerical simulations based on Fick's laws are in agreement with the experimental results and provide to estimate the effective diffusion coefficient of formaldehyde through the membrane (3.50 × 10(-6) m(2) s(-1)). Conversion factors between the sensor response, sampled formaldehyde mass and sampling rate were also assessed.

  19. Detection of biological molecules using boronate-based chemical amplification and optical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Antwerp, W.P. van; Mastrototaro, J.J.; Lane, S.M.; Satcher, J.H. Jr.; Darrow, C.B.; Peyser, T.A.; Harder, J.

    1999-12-14

    Methods are provided for the determination of the concentration of biological levels of polyhydroxylated compounds, particularly glucose. The methods utilize an amplification system that is an analyte transducer immobilized in a polymeric matrix, where the system is implantable and biocompatible. Upon interrogation by an optical system, the amplification system produces a signal capable of detection external to the skin of the patient. Quantitation of the analyte of interest is achieved by measurement of the emitted signal.

  20. Gold island fiber optic sensor

    Science.gov (United States)

    Meriaudeau, Fabrice; Wig, A. G.; Passian, A.; Downey, Todd R.; Buncick, Milan; Ferrell, Trinidad L.

    1999-12-01

    A fiber optic chemical sensor based on gold-island surface plasmon excitation is presented. The sensing part of the fiber is the end of the fiber onto which a thin layer of gold has been deposited to form a particulate surface. Annealing the gold reshapes the particles and produces an optical absorbance near 535 nm with the fiber in air. The optical absorption resonance of the gold particles is shifted if the fiber is immersed in a medium other than air. These resonance shifts are examined by transmission spectroscopy through the fiber. Experimental results for the sensitivity and dynamic range in the measurement of liquid solutions are in agreement with a basic theoretical model which characterizes the surface plasmon using nonretarded electrodynamics.

  1. Development Of Porous Glass Fiber Optic Sensors

    Science.gov (United States)

    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.

  2. Porous glasses for optical sensors

    Science.gov (United States)

    Dorosz, Dominik; Procyk, Bernadeta

    2006-03-01

    Microporous glasses from the Na II0-B II0 3-Si0 II system can be obtained by appropriate thermal and chemical treatment. During the thermal treatment the separation of the borate phase from the silicon skeleton has been occurred. The borates are in the form small drops joined to each other. In the course of chemical treatment the borates become leached in water, water solutions of acids or basis and the glass becomes porous. Microporous glasses may find application in many branches of science and engineering. The applications depend on the internal arrangement, size and shape of pores. These parameters may be in a wide range modified by a change of the chemical composition. The received porous glass was used as an element in optical fibre NO II sensor. The specific coloration reaction between organic reagents and NO II in the pores was occurred. It is possible to detection of 10-50 ppm NO II level.

  3. Fiber optic hydrogen sensor

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-05-01

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

  4. Imprinted photonic crystal chemical sensors

    NARCIS (Netherlands)

    Boersma, A.; Burghoorn, M.M.A.; Saalmink, M.

    2011-01-01

    In this paper we present the use of Photonic Crystals as chemical sensors. These 2D nanostructured sensors were prepared by nano-imprint lithography during which a nanostructure is transferred from a nickel template into a responsive polymer, that is be specifically tuned to interact with the chemic

  5. Fiber-Optic Sensor Facility

    Data.gov (United States)

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

  6. Interferometric Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    Hae Young Choi

    2012-02-01

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

  7. Interferometric fiber optic sensors.

    Science.gov (United States)

    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. Optical technologies for space sensor

    Science.gov (United States)

    Wang, Hu; Liu, Jie; Xue, Yaoke; Liu, Yang; Liu, Meiying; Wang, Lingguang; Yang, Shaodong; Lin, Shangmin; Chen, Su; Luo, Jianjun

    2015-10-01

    Space sensors are used in navigation sensor fields. The sun, the earth, the moon and other planets are used as frame of reference to obtain stellar position coordinates, and then to control the attitude of an aircraft. Being the "eyes" of the space sensors, Optical sensor system makes images of the infinite far stars and other celestial bodies. It directly affects measurement accuracy of the space sensor, indirectly affecting the data updating rate. Star sensor technology is the pilot for Space sensors. At present more and more attention is paid on all-day star sensor technology. By day and night measurements of the stars, the aircraft's attitude in the inertial coordinate system can be provided. Facing the requirements of ultra-high-precision, large field of view, wide spectral range, long life and high reliability, multi-functional optical system, we integration, integration optical sensors will be future space technology trends. In the meantime, optical technologies for space-sensitive research leads to the development of ultra-precision optical processing, optical and precision test machine alignment technology. It also promotes the development of long-life optical materials and applications. We have achieved such absolute distortion better than ±1um, Space life of at least 15years of space-sensitive optical system.

  9. Nanomaterials and Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Sukumar BASU

    2011-11-01

    Full Text Available Nanomaterials and nanosensors are two most important iconic words of the modern science & Technology. Though nano technology is relatively a new area of research & development it will soon be included in the most modern electronic circuitry used for advanced computing systems. Since it will provide the potential link between the nanotechnology and the macroscopic world the development is primarily directed towards exploitation of nanotechnology to computer chip miniaturization and vast storage capacity. However, for implementation in the consumer products the present high cost of production must be overcome. There are different ways to make nanosensors e.g. top-down lithography, bottom-up assembly, and self molecular assembly. Consequently, nanomaterials & nanosensors have to be made compatible with the consumer technologies. The progress in detecting and sensing different chemical species with increased accuracy may transform the human society from uncertainty and inaccuracy to more precise and definite world of information. For example, extremely low concentrations of air pollutants or toxic materials in air & water around us can be accurately and economically detected in no time to save the human beings from the serious illnesses. Also, the medical sensors will help in diagnoses of the diseases, their treatment and in predicting the future profile of the individual so that the health insurance companies may exploit the opportunity to grant or to deny the health coverage. Other social issues like privacy invasion and security may be best monitored by the widespread use of the surveillance devices using nanosensors.

  10. Plasma-enhanced chemical vapor deposited silicon oxynitride films for optical waveguide bridges for use in mechanical sensors

    DEFF Research Database (Denmark)

    Storgaard-Larsen, Torben; Leistiko, Otto

    1997-01-01

    In this paper the influence of RF power, ammonia flow, annealing temperature, and annealing time on the optical and mechanical properties of plasma-enhanced chemically vapor deposited silicon oxynitride films, is presented. A low refractive index (1.47 to 1.48) film having tensile stress has been...

  11. Graphene Chemical Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The sensor uses graphene based devices to sense the surface potential of a graphene channel exposed to an analyte. When analyte molecules adsorb onto the...

  12. Graphene Chemical Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The sensor uses graphene based devices to sense the surface potential of a graphene channel exposed to an analyte. When analyte molecules adsorb onto the...

  13. Fiber Optic Geophysics Sensor Array

    Science.gov (United States)

    Grochowski, Lucjan

    1989-01-01

    The distributed optical sensor arrays are analysed in view of specific needs of 3-D seismic explorations methods. There are compared advantages and disadventages of arrays supported by the sensors which are modulated in intensity and phase. In these systems all-fiber optic structures and their compabilities with digital geophysic formats are discussed. It was shown that the arrays based on TDM systems with the intensity modulated sensors are economically and technically the best matched for geophysic systems supported by a large number of the sensors.

  14. Optical Landing Hazard Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Visidyne proposes to investigate an active optical 3D imaging LADAR as the sensor for an automated Landing Hazard Avoidance system for spacecraft landing on the Moon...

  15. Fiber Optic Magnetic Sensor Research.

    Science.gov (United States)

    1983-02-28

    Michelson inter- ferometric fiber optical point temperature sensor (Appendix B). The sensor has potential applicntion to non-invnsive and high...3roeniheaingUsing similar techniques, to for monolithic circuits. Lange couplers have been fabricated on alumina substrates. The: re- Fig 3 illustrates

  16. Optical fibre cantilever sensor for biological application

    Science.gov (United States)

    Li, J.; Zhou, Y. X.; Patterson, G.; Shu, W. M.; Maier, R. R. J.; Fowler, R.; Hand, D. P.; MacPherson, W. N.

    2014-05-01

    Micro-cantilever sensors have shown great promise in a wide range of application are as including chemical and biological sensing. However, many of these devices are based upon a sensor `chip' that requires careful alignment between the cantilever and the read-out system, which can be challenging. Furthermore, optical interrogation typically involves a bulky free-space system. Optical fibre addressed cantilevers have been reported previously in the literature and in this paper we propose techniques to design and fabricate polymer micro-cantilevers for attachment onto the end of standard single mode fibres using laser machining. Low-cost optical sources and a fibre coupled spectrometer are employed to monitor the cantilever deflection and therefore observe biological binding between a species of interest and an activated cantilever. Proof-of-concept experiments show that the sensor is capable of detecting pathogen concentration with down to a level of 105cfu/ml.

  17. Fiber optic liquid refractive index sensor

    Science.gov (United States)

    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.

  18. Optical networks for wideband sensor array

    Science.gov (United States)

    Sheng, Lin Horng

    2011-12-01

    This thesis presents the realization of novel systems for optical sensing networks with an array of long-period grating (LPG) sensors. As a launching point of the thesis, the motivation to implement optical sensing network in precisely catering LPG sensors is presented. It highlights the flexibility of the sensing network to act as the foundation in order to boost the application of the various LPG sensor design in biological and chemical sensing. After the thorough study on the various optical sensing networks, sub-carrier multiplexing (SCM) and optical time division multiplexing (OTDM) schemes are adopted in conjunction with tunable laser source (TLS) to facilitate simultaneous interrogation of the LPG sensors array. In fact, these systems are distinct to have the capability to accommodate wideband optical sensors. Specifically, the LPG sensors which is in 20nm bandwidth are identified to operate in these systems. The working principles of the systems are comprehensively elucidated in this thesis. It highlights the mathematical approach to quantify the experimental setup of the optical sensing network. Additionally, the system components of the designs are identified and methodically characterized so that the components well operate in the designed environment. A mockup has been setup to demonstrate the application in sensing of various liquid indices and analyse the response of the LPG sensors in order to evaluate the performance of the systems. Eventually, the resemblance of the demultiplexed spectral response to the pristine spectral response are quantified to have excellent agreement. Finally, the promising result consistency of the systems is verified through repeatability test.

  19. Adaptive optical zoom sensor.

    Energy Technology Data Exchange (ETDEWEB)

    Sweatt, William C.; Bagwell, Brett E.; Wick, David Victor

    2005-11-01

    In order to optically vary the magnification of an imaging system, continuous mechanical zoom lenses require multiple optical elements and use fine mechanical motion to precisely adjust the separations between individual or groups of lenses. By incorporating active elements into the optical design, we have designed and demonstrated imaging systems that are capable of variable optical magnification with no macroscopic moving parts. Changing the effective focal length and magnification of an imaging system can be accomplished by adeptly positioning two or more active optics in the optical design and appropriately adjusting the optical power of those elements. In this application, the active optics (e.g. liquid crystal spatial light modulators or deformable mirrors) serve as variable focal-length lenses. Unfortunately, the range over which currently available devices can operate (i.e. their dynamic range) is relatively small. Therefore, the key to this concept is to create large changes in the effective focal length of the system with very small changes in the focal lengths of individual elements by leveraging the optical power of conventional optical elements surrounding the active optics. By appropriately designing the optical system, these variable focal-length lenses can provide the flexibility necessary to change the overall system focal length, and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses.

  20. Micro-fabricated all optical pressure sensors

    DEFF Research Database (Denmark)

    Havreland, Andreas Spandet; Petersen, Søren Dahl; Østergaard, Christian

    2017-01-01

    Optical pressure sensors can operate in certain harsh application areas where the electrical pressure sensors cannot. However, the sensitivity is often not as good for the optical sensors. This work presents an all optical pressure sensor, which is fabricated by micro fabrication techniques, wher...

  1. All-optical pressure sensor

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to an all-optical pressure sensor comprising a waveguide accommodating a distributed Bragg reflector. Pressure sensing can then be provided by utilizing effective index modulation of the waveguide and detection of a wavelength shift of light reflected from the Bragg...... reflector. Sound sensing may also be provided thereby having an all-optical microphone. One embodiment of the invention relates to an optical pressure sensor comprising at least one outer membrane and a waveguide, the waveguide comprising at least one core for confining and guiding light,at least one...... distributed Bragg reflector located in said at least one core, and at least one inner deflecting element forming at least a part of the core,wherein the pressure sensor is configured such that the geometry and/or dimension of the at least one core is changed when the at least one outer membrane is submitted...

  2. Fiber optic sensor and method for making

    Science.gov (United States)

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

    2010-05-18

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

  3. Fiber-Optic Temperature Sensor

    Science.gov (United States)

    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.

  4. Wearable optical sensor

    OpenAIRE

    Pereira, Maurício Neves Rodrigues da Silva

    2008-01-01

    Neste trabalho foi desenvolvido um sensor para medição do ângulo de flexão do cotovelo de um indivíduo. Este sensor é uma ajuda na aferição da recuperação de uma pessoa que sofreu um acidente cardiovascular e que tenha perdido mobilidade no conjunto ombro-braço. Embora o sensor por si só não desempenhe uma função vital na recuperação de um paciente com as características referidas, espera-se que se torne uma ajuda na motivação da pessoa bem como uma maneira de quantificar o ...

  5. Optical Fiber Grating based Sensors

    DEFF Research Database (Denmark)

    Michelsen, Susanne

    2003-01-01

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

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

    Science.gov (United States)

    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.

  7. Sensores ópticos com detecção no infravermelho próximo e médio Near and mid infrared optical sensors

    Directory of Open Access Journals (Sweden)

    Kássio M. G. Lima

    2009-01-01

    Full Text Available Optical chemical sensors with detection in the near and mid infrared region are reviewed. Fundamental concepts of infrared spectroscopy and optical chemical sensors are briefly described, before presenting some aspects on optical chemical sensors, such as synthesis of NIR and IR reagents, preparation of new materials as well as application in determinations of species of biological, industrial and environmental importance.

  8. In-situ, Real-Time Monitoring of Mechanical and Chemical Structure Changes in a V2O5 Battery Electrode Using a MEMS Optical Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. [University of Maryland; Gerasopoulos, K. [University of Maryland; Gnerlich, Markus [University of Maryland; Talin, A. Alec [Sandia National Laboratories; Ghodssi, Reza [University of Maryland

    2014-06-01

    This work presents the first demonstration of a MEMS optical sensor for in-situ, real-time monitoring of both mechanical and chemical structure evolutions in a V2O5 lithium-ion battery (LIB) cathode during battery operation. A reflective membrane forms one side of a Fabry-Perot (FP) interferometer, while the other side is coated with V2O5 and exposed to electrolyte in a half-cell LIB. Using one microscope and two laser sources, both the induced membrane deflection and the corresponding Raman intensity changes are observed during lithium cycling. Results are in good agreement with the expected mechanical behavior and disorder change of the V2O5 layers, highlighting the significant potential of MEMS as enabling tools for advanced scientific investigations.

  9. Advanced millimeter wave chemical sensor.

    Energy Technology Data Exchange (ETDEWEB)

    Gopalsami, N.

    1999-03-24

    This paper discusses the development of an advanced millimeter-wave (mm-wave) chemical sensor and its applications for environmental monitoring and arms control treaty verification. The purpose of this work is to investigate the use of fingerprint-type molecular rotational signatures in the mm-wave spectrum to sense airborne chemicals. The mm-wave spectrum to sense airborne chemicals. The mm-wave sensor, operating in the frequency range of 220-300 GHz, can work under all weather conditions and in smoky and dusty environments. The basic configuration of the mm-wave sensor is a monostatic swept-frequency radar consisting of a mm-wave sweeper, a hot-electron-bolometer or Schottky barrier detector, and a trihedral reflector. The chemical plume to be detected is situated between the transmitter/detector and the reflector. Millimeter-wave absorption spectra of chemicals in the plume are determined by measuring the swept-frequency radar return signals with and without the plume in the beam path. The problem of pressure broadening, which hampered open-path spectroscopy in the past, has been mitigated in this work by designing a fast sweeping source over a broad frequency range. The heart of the system is a Russian backward-wave oscillator (BWO) tube that can be tuned over 220-350 GHz. Using the Russian BWO tube, a mm-wave radar system was built and field-tested at the DOE Nevada Test Site at a standoff distance of 60 m. The mm-wave system detected chemical plumes very well; the detection sensitivity for polar molecules like methyl chloride was down to a concentration of 12 ppm.

  10. Distributed optical fiber surface plasmon resonance sensors

    Institute of Scientific and Technical Information of China (English)

    Zhenxin Cao; Lenan Wu; Dayong Li

    2006-01-01

    @@ The relationships of the resonant wavelength of optical fiber surface plasmon resonance (SPR) sensors to the modulation layer refractive index, thickness and the refractive index of the bulk medium are obtained by using theoretical calculation model of optical fiber SPR sensors under certain conditions, which indicates that resonant wavelength of the sensors is approximately linear with modulation layer thickness. Based on the linear relationship, multiple SPR sensors with different resonant wavelengths can be fabricated in a single optical fiber named as distributed optical fiber surface plasmon resonance sensors (DOFSPRSs).Experimental results are presented, showing that it is practical to fabricate more than one SPR sensors in a single optical fiber.

  11. Structural health monitoring with fiber optic sensors

    Institute of Scientific and Technical Information of China (English)

    F.ANSARI

    2009-01-01

    Optical fiber sensors have been successfully implemented in aeronautics, mechanical systems, and medical applications. Civil structures pose further challenges in monitoring mainly due to their large dimensions, diversity and heterogeneity of materials involved, and hostile construction environment. This article provides a summary of basic principles pertaining to practical health monitoring of civil engineering structures with optical fiber sensors. The issues discussed include basic sensor principles, strain transfer mechanism, sensor packaging, sensor placement in construction environment, and reliability and survivability of the sensors.

  12. High pressure fiber optic sensor system

    Science.gov (United States)

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

    2013-11-26

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

  13. Optical rotation sensors

    Science.gov (United States)

    Rotge, J. R.; Simmons, B. J.; Kroncke, G. T.; Stech, D. J.

    1986-05-01

    Research efforts were concentrated on passive ring laser rotation sensor technology. Initial efforts were performed on supportive projects, e.g., laser stabilization, followed by a 0.62 sq m passive resonant ring laser gyro (PRRLG), leading to the development of a 60 sq m system mounted on the pneumatically supported isolation test platform (Iso-Pad) at FJSRL. Numerous sub-system tasks and a feasibility 0.62 sq m PRRLG were completed, supporting projections of very high resolution performance by a large 60 sq m PRRLG. The expected performance of the large PRRLG, on the order of 10 to the minus 10th power ERU (earth rate units), would provide an accurate error model applicable to Air Force operational ring laser gyros, a new source of geophysical data, e.g., earth wobble and variations in earth rotation, a proven design concept applicable to Air Force sensor needs as reference to MX instruments tests, and relativity experiments. This report documents the many accomplishments leading to, and the status of the large PRRLG at the date of the PRRLG stop order, November 1985.

  14. Overview of Fiber-Optical Sensors

    Science.gov (United States)

    Depaula, Ramon P.; Moore, Emery L.

    1987-01-01

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

  15. Submersible optical sensors exposed to chemically dispersed crude oil: wave tank simulations for improved oil spill monitoring.

    Science.gov (United States)

    Conmy, Robyn N; Coble, Paula G; Farr, James; Wood, A Michelle; Lee, Kenneth; Pegau, W Scott; Walsh, Ian D; Koch, Corey R; Abercrombie, Mary I; Miles, M Scott; Lewis, Marlon R; Ryan, Scott A; Robinson, Brian J; King, Thomas L; Kelble, Christopher R; Lacoste, Jordanna

    2014-01-01

    In situ fluorometers were deployed during the Deepwater Horizon (DWH) Gulf of Mexico oil spill to track the subsea oil plume. Uncertainties regarding instrument specifications and capabilities necessitated performance testing of sensors exposed to simulated, dispersed oil plumes. Dynamic ranges of the Chelsea Technologies Group AQUAtracka, Turner Designs Cyclops, Satlantic SUNA and WET Labs, Inc. ECO, exposed to fresh and artificially weathered crude oil, were determined. Sensors were standardized against known oil volumes and total petroleum hydrocarbons and benzene-toluene-ethylbenzene-xylene measurements-both collected during spills, providing oil estimates during wave tank dilution experiments. All sensors estimated oil concentrations down to 300 ppb oil, refuting previous reports. Sensor performance results assist interpretation of DWH oil spill data and formulating future protocols.

  16. Optical viscosity sensor

    Science.gov (United States)

    Chang, Cheng-Ling; Peyroux, Juliette; Perez, Alex; Tsui, Chi-Leung; Wang, Wei-Chih

    2009-03-01

    Viscosity measurement by bend loss of fiber is presented. The sensing principle makes use of the damping characteristic of a vibrating optical fiber probe with fix-free end configuration. By measuring the displacement of the fiber probe, the viscosity can be determined by matching the probe's displacement with the displacement built in the database obtained by either experimental method or Finite element calculation. Experimental results are presented by measuring the sucrose and glycerol solutions of different concentrations with a viscosity varying from 1 to 15 cP. Stokes' flow assumption is utilized to attenuate the mass density effect and simplify the viscosity measurement.

  17. Optical Sensors Based on Plastic Fibers

    Science.gov (United States)

    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

  18. Optical Sensors Based on Plastic Fibers

    Directory of Open Access Journals (Sweden)

    Rogério Nogueira

    2012-09-01

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

  19. Porous Silicon Structures as Optical Gas Sensors

    Directory of Open Access Journals (Sweden)

    Igor A. Levitsky

    2015-08-01

    Full Text Available We present a short review of recent progress in the field of optical gas sensors based on porous silicon (PSi and PSi composites, which are separate from PSi optochemical and biological sensors for a liquid medium. Different periodical and nonperiodical PSi photonic structures (bares, modified by functional groups or infiltrated with sensory polymers are described for gas sensing with an emphasis on the device specificity, sensitivity and stability to the environment. Special attention is paid to multiparametric sensing and sensor array platforms as effective trends for the improvement of analyte classification and quantification. Mechanisms of gas physical and chemical sorption inside PSi mesopores and pores of PSi functional composites are discussed.

  20. Enzyme-Based Fiber Optic Sensors

    Science.gov (United States)

    Kulp, Thomas J.; Camins, Irene; Angel, Stanley M.

    1988-06-01

    Fiber optic chemical sensors capable of detecting glucose and penicillin were developed. Each consists of a polymer membrane that is covalently attached to the tip of a glass optical fiber. The membrane contains the enzyme and a pH-sensitive fluorescent dye (fluorescein). A signal is produced when the enzyme catalyzes the conversion of the analyte (glucose or penicillin) into a product (gluconic or penicilloic acid, respectively) that lowers the microenvironmental pH of the membrane and, consequently, lowers the fluorescence intensity of the dye. Each sensor is capable of responding to analyte concentrations in the range of ~0.1 to 100 mM. The penicillin optrode response time is 40 to 60 s while that for glucose is ~5 to 12 min.

  1. Threshold temperature optical fibre sensors

    Science.gov (United States)

    Stasiewicz, K. A.; Musial, J. E.

    2016-12-01

    This paper presents a new approach to manufacture a threshold temperature sensor based on a biconical optical fibre taper. The presented sensor employs the influence of variable state of concentration of some isotropic materials like wax or paraffin. Application of the above- mentioned materials is an attempt to prove that there is a possibility to obtain a low-cost, repeatable and smart sensor working as an in-line element. Optical fibre taper was obtained from a standard single mode fibre (SMF28®) by using a low pressure gas burner technique. The diameter of the manufactured tapers was 6.0 ± 0.5 μm with the length of elongation equal to 30.50 ± 0.16 mm. The applied technology allowed to produce tapers with the losses of 0.183 ± 0.015 dB. Application of materials with different temperature transition points made it possible to obtain the threshold work at the temperatures connected directly with their conversion temperature. External materials at the temperatures above their melting points do not influence the propagation losses. For each of them two types of the protection area and position of the optical fibre taper were applied.

  2. Ubiquitous Sensor Network for Chemical Sensors

    Institute of Scientific and Technical Information of China (English)

    Wan-Young Chung; Risto Myllylae

    2006-01-01

    Wireless sensor networks have been identified as one of the most important technologies for the 21st century. Recent advances in micro sensor fabrication technology and wireless communication technology enable the practical deployment of large-scale, low-power, inexpensive sensor networks. Such an approach offers an advantage over traditional sensing methods in many ways: large-scale, dense deployment not only extends spatial coverage and achieves higher resolution, but also increases the system's fault-tolerance and robustness. Moreover, the ad-hoc nature of wireless sensor networks makes them even more attractive for military and other risk-associated applications, such as environmental observation and habitat monitoring.

  3. Great prospects for fiber optics sensors

    Science.gov (United States)

    Hansen, T. E.

    1983-10-01

    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.

  4. Fiber optic sensors for smart taxiways

    Science.gov (United States)

    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.

  5. Fibre Optic Sensors for Selected Wastewater Characteristics

    Directory of Open Access Journals (Sweden)

    Sulaiman W. Harun

    2013-07-01

    Full Text Available Demand for online and real-time measurements techniques to meet environmental regulation and treatment compliance are increasing. However the conventional techniques, which involve scheduled sampling and chemical analysis can be expensive and time consuming. Therefore cheaper and faster alternatives to monitor wastewater characteristics are required as alternatives to conventional methods. This paper reviews existing conventional techniques and optical and fibre optic sensors to determine selected wastewater characteristics which are colour, Chemical Oxygen Demand (COD and Biological Oxygen Demand (BOD. The review confirms that with appropriate configuration, calibration and fibre features the parameters can be determined with accuracy comparable to conventional method. With more research in this area, the potential for using FOS for online and real-time measurement of more wastewater parameters for various types of industrial effluent are promising.

  6. Fibre optic sensors for selected wastewater characteristics.

    Science.gov (United States)

    Chong, Su Sin; Aziz, A R Abdul; Harun, Sulaiman W

    2013-07-05

    Demand for online and real-time measurements techniques to meet environmental regulation and treatment compliance are increasing. However the conventional techniques, which involve scheduled sampling and chemical analysis can be expensive and time consuming. Therefore cheaper and faster alternatives to monitor wastewater characteristics are required as alternatives to conventional methods. This paper reviews existing conventional techniques and optical and fibre optic sensors to determine selected wastewater characteristics which are colour, Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD). The review confirms that with appropriate configuration, calibration and fibre features the parameters can be determined with accuracy comparable to conventional method. With more research in this area, the potential for using FOS for online and real-time measurement of more wastewater parameters for various types of industrial effluent are promising.

  7. Volatile organic compound optical fiber sensors: a review

    OpenAIRE

    Arregui, Francisco J.; Candido Bariain; Matias, Ignacio R; Cesar Elosua

    2006-01-01

    Volatile organic compound (VOC) detection is a topic of growing interest with applications in diverse fields, ranging from environmental uses to the food or chemical industries. Optical fiber VOC sensors offering new and interesting properties which overcame some of the inconveniences found on traditional gas sensors appeared over two decades ago. Thanks to its minimum invasive nature and the advantages that optical fiber offers such as light weight, passive nature, low attenuation and the...

  8. Fiber Optic Pressure Sensor Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array for measuring air flow pressure at multiple points on the skin of aircrafts for Flight Load Test...

  9. Fiber Optic Pressure Sensor Array Project

    Data.gov (United States)

    National Aeronautics and Space Administration — VIP Sensors proposes to develop a Fiber Optic Pressure Sensor Array System for measuring air flow pressure at multiple points on the skin of aircrafts for Flight...

  10. Semiconductor Quantum Dots in Chemical Sensors and Biosensors

    Directory of Open Access Journals (Sweden)

    Nikos Chaniotakis

    2009-09-01

    Full Text Available Quantum dots are nanometre-scale semiconductor crystals with unique optical properties that are advantageous for the development of novel chemical sensors and biosensors. The surface chemistry of luminescent quantum dots has encouraged the development of multiple probes based on linked recognition molecules such as peptides, nucleic acids or small-molecule ligands. This review overviews the design of sensitive and selective nanoprobes, ranging from the type of target molecules to the optical transduction scheme. Representative examples of quantum dot-based optical sensors from this fast-moving field have been selected and are discussed towards the most promising directions for future research.

  11. Multilayer fiber optic chemical sensors employing organically modified SiO2 and mixed TiO2/SiO2 sol gel membranes

    Science.gov (United States)

    Nivens, Delana A.; Schiza, Maria V.; Angel, S. M.

    1997-05-01

    Fiber-optic sensors have been developed that incorporate multi-layer organically modified silica sol-gel membranes. pH sensors use a single layer hydrophilic organo-silica sol-gel membrane with a covalently attached pH sensitive dye, hydroxypyrene trisulfonic acid. The hydrophilic coating is made by copolymerizing silanol-terminated polydimethylsiloxane and tetraethylorthosilicate with 3-aminopropyltriethoxysilane. Unlike previous methods, which use acid as a catalyst, we have found that a base catalyst produces optically transparent gels. The sol-gel coated sensors are simple to make and require drying and aging times of as little as one day. Sensors made using these gels exhibit very good long-term stability, fast response times and no dye leaching. pCO2 sensors were fabricated using the same pH sensitive sol-gel layer overcoated with a hydrophobic high organic content sol- gel membrane. The response of the pH and pCO2 sensors is very fast due to the high porosity of the sol-gel membranes. Although in-situ sensors have been described for a number of organic and inorganic species, many volatile organochloride compounds (VOCs), such as perchloroethylene (PCE) and trichloroethylene (TCE), have been difficult to measure using current fiber-optic sensor transduction schemes. One of the optical sensors described here is a multilayer (3-4) sol-gel system that incorporates a TiO2/SiO2 membrane to degrade VOCs into smaller, detectable products. Upon exposure to UV light, TiO2, a semiconductor with a bandgap of 3.2 eV, produces highly reactive electron-hole pairs that are capable of photodegrading most organic compounds. The VOCs mentioned above are sensitive to degradative oxidation on TiO2 surfaces. During photodegradation of VOCs a number of products are formed including H+, HCl, CO2 and a number of smaller hydrocarbons. These products are produced in the TiO2 membrane and on TiO2 surfaces and the products diffuse into the nearby indicator membrane where they are

  12. Guard Cell and Tropomyosin Inspired Chemical Sensor

    Directory of Open Access Journals (Sweden)

    Jacquelyn K.S. Nagel

    2013-10-01

    Full Text Available Sensors are an integral part of many engineered products and systems. Biological inspiration has the potential to improve current sensor designs as well as inspire innovative ones. This paper presents the design of an innovative, biologically-inspired chemical sensor that performs “up-front” processing through mechanical means. Inspiration from the physiology (function of the guard cell coupled with the morphology (form and physiology of tropomyosin resulted in two concept variants for the chemical sensor. Applications of the sensor design include environmental monitoring of harmful gases, and a non-invasive approach to detect illnesses including diabetes, liver disease, and cancer on the breath.

  13. Nanotube-Based Chemical and Biomolecular Sensors

    Institute of Scientific and Technical Information of China (English)

    J.Koh; B.Kim; S.Hong; H.Lim; H.C.Choi

    2008-01-01

    We present a brief review about recent results regarding carbon nanotube (CNT)-based chemical and biomolecular sensors. For the fabrication of CNT-based sensors, devices containing CNT channels between two metal electrodes are first fabricated usually via chemical vapor deposition (CVD) process or "surface programmed assembly" method. Then, the CNT surfaces are often functionalized to enhance the selectivity of the sensors. Using this process, highly-sensitive CNT-based sensors can be fabricated for the selective detection of various chemical and biological molecules such as hydrogen, ammonia, carbon monoxide, chlorine gas, DNA, glucose, alcohol, and proteins.

  14. Optical seismic sensor systems and methods

    Science.gov (United States)

    Beal, A. Craig; Cummings, Malcolm E.; Zavriyev, Anton; Christensen, Caleb A.; Lee, Keun

    2015-12-08

    Disclosed is an optical seismic sensor system for measuring seismic events in a geological formation, including a surface unit for generating and processing an optical signal, and a sensor device optically connected to the surface unit for receiving the optical signal over an optical conduit. The sensor device includes at least one sensor head for sensing a seismic disturbance from at least one direction during a deployment of the sensor device within a borehole of the geological formation. The sensor head includes a frame and a reference mass attached to the frame via at least one flexure, such that movement of the reference mass relative to the frame is constrained to a single predetermined path.

  15. Assessment of fiber optic pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-04-01

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

  16. Fiber optic sensors current status and future possibilities

    CERN Document Server

    Ikezawa, Satoshi; Corres, Jesus

    2017-01-01

    This book describes important recent developments in fiber optic sensor technology and examines established and emerging applications in a broad range of fields and markets, including power engineering, chemical engineering, bioengineering, biomedical engineering, and environmental monitoring. Particular attention is devoted to niche applications where fiber optic sensors are or soon will be able to compete with conventional approaches. Beyond novel methods for the sensing of traditional parameters such as strain, temperature, and pressure, a variety of new ideas and concepts are proposed and explored. The significance of the advent of extended infrared sensors is discussed, and individual chapters focus on sensing at THz frequencies and optical sensing based on photonic crystal structures. Another important topic is the resonances generated when using thin films in conjunction with optical fibers, and the enormous potential of sensors based on lossy mode resonances, surface plasmon resonances, and long-range...

  17. Integrated Differential Optical Shadow Sensor for Modular Gravitational Reference Sensor

    CERN Document Server

    Zoellner, Andreas; Sun, Ke-Xun

    2013-01-01

    The Laser Interferometer Space Antenna (LISA) is a proposed space mission for the detection of gravitational waves. It consists of three drag-free satellites flying in a triangular constellation. A gravitational reference sensor is used in conjunction with a laser interferometer to measure the distance between test masses inside the three satellites. Other future space mission such as DECIGO and BBO also require a gravitational reference sensor. The Modular Gravitational Reference Sensor (MGRS) is being designed for these purposes and consists of two different optical sensors and a UV LED charge management system. The Differential Optical Shadow Sensor (DOSS) is one of the optical sensors and measures the position of a spherical test mass with respect to the surrounding satellite. This measurement is used for the drag-free feedback control loop. This paper describes the most recent, third generation of the experimental setup for the DOSS that uses a fiber coupled super luminescent LED, an integrated mounting ...

  18. Reversible NO2 Optical Fiber Chemical Sensor Based on LuPc2 Using Simultaneous Transmission of UV and Visible Light.

    Science.gov (United States)

    Bueno, Antonio; Lahem, Driss; Caucheteur, Christophe; Debliquy, Marc

    2015-04-27

    In this paper, an NO2 optical fiber sensor is presented for pollution monitoring in road traffic applications. This sensor exploits the simultaneous transmission of visible light, as a measurement signal, and UV light, for the recovery of the NO2 sensitive materials. The sensor is based on a multimode fiber tip coated with a thin film of lutetium bisphthalocyanine (LuPc2). The simultaneous injection of UV light through the fiber is an improvement on the previously developed NO2 sensors and allows the simplification of the sensor head, rendering the external UV illumination of the film unnecessary. Coatings of different thicknesses were deposited on the optical fiber tips and the best performance was obtained for a 15 nm deposited thickness, with a sensitivity of 5.02 mV/ppm and a resolution of 0.2 ppb in the range 0-5 ppm. The response and recovery times are not dependent on thickness, meaning that NO2 does not diffuse completely in the films.

  19. Passive in-situ chemical sensor

    Science.gov (United States)

    Morrell, Jonathan S.; Ripley, Edward B.

    2012-02-14

    A chemical sensor for assessing a chemical of interest. In typical embodiments the chemical sensor includes a first thermocouple and second thermocouple. A reactive component is typically disposed proximal to the second thermal couple, and is selected to react with the chemical of interest and generate a temperature variation that may be detected by a comparison of a temperature sensed by the second thermocouple compared with a concurrent temperature detected by the first thermocouple. Further disclosed is a method for assessing a chemical of interest and a method for identifying a reaction temperature for a chemical of interest in a system.

  20. Waveguide Zeeman interferometry for thin-film chemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Grace, K.M.; Shrouf, K.; Johnston, R.G.; Yang, X.; Swanson, B. [Los Alamos National Lab., NM (United States); Honkanen, S.; Ayras, P.; Peyghambarian, N. [Optical Sciences Center, Univ. of Arizona, Tucson, AZ (United States); Katila, P.; Leppihalme, M. [VTT Electronics (Finland)

    1997-10-01

    A chemical sensor is demonstrated which is based on Si{sub 3}N{sub 4} optical waveguides coated with species-selective thin films and using Zeeman interferometry as the detection technique. Relative phase change between TE and TM modes is measured. Real time and reversible response to toluene is shown with ppm level sensitivity.

  1. Miniaturised optical sensors for industrial applications

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Hanson, Steen Grüner

    2010-01-01

    When addressing optical sensors for use in e.g. industry, compactness, robustness and performance are essentials. Adhering to these demands, we have developed a suit of compact optical sensors for the specific purposes of measuring angular velocity and linear translations of rigid objects...

  2. Digitally encoded all-optical sensor multiplexing

    Science.gov (United States)

    Pervez, Anjum

    1992-01-01

    A digital, all-optical temperature sensor design concept based on optical sampling and digital encoding is presented. The proposed sensor generates 2M binary digital codewords of length M bits. The codewords are generated serially and, therefore, only a single output fiber line is required. A multiplexing scheme, which minimizes the power requirement per sensor array and facilitates a cost-effective digit regeneration for remote monitoring over long distance, is presented. The sensor arrays are used as building blocks to configure large scale sensor networks based on LAN topologies.

  3. Semiconductor Quantum Dots in Chemical Sensors and Biosensors

    OpenAIRE

    Nikos Chaniotakis; Frasco, Manuela F.

    2009-01-01

    Quantum dots are nanometre-scale semiconductor crystals with unique optical properties that are advantageous for the development of novel chemical sensors and biosensors. The surface chemistry of luminescent quantum dots has encouraged the development of multiple probes based on linked recognition molecules such as peptides, nucleic acids or small-molecule ligands. This review overviews the design of sensitive and selective nanoprobes, ranging from the type of target molecules to the optical ...

  4. Chemical sensors based on molecularly modified metallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Haick, Hossam [Department of Chemical Engineering and Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, Haifa 32000 (Israel)

    2007-12-07

    This paper presents a concise, although admittedly non-exhaustive, didactic review of some of the main concepts and approaches related to the use of molecularly modified metal nanoparticles in or as chemical sensors. This paper attempts to pull together different views and terminologies used in sensors based on molecularly modified metal nanoparticles, including those established upon electrochemical, optical, surface Plasmon resonance, piezoelectric and electrical transduction approaches. Finally, this paper discusses briefly the main advantages and disadvantages of each of the presented class of sensors. (review article)

  5. Photothermal determination of optical coefficients using an optical fibre sensor

    CERN Document Server

    Laufer, J

    2000-01-01

    configuration is more sensitive to the thermal coefficients than the optical coefficients of the target. Pulsed photothermal radiometry was found to have higher sensitivity to the optical coefficients than has the optical fibre sensor in its present form. However, modifications to the configuration of the sensor can produce a performance matching that of pulsed photothermal radiometry. This thesis is concerned with the development of an optical fibre sensor for the photothermal determination of the optical coefficients of tissue. The detection of differences in tissue optical properties might be used for the diagnosis of cancers and other tissue pathologies. The sensor consists of a thin transparent polymer film mounted at the distal end of an optical fibre. The film acts as a Fabry-Perot interferometer. The absorption of short, low energy laser pulses transmitted through the film and into the tissue generates thermal as well as acoustic transients, which propagate into/the film and modulate its thickness. Th...

  6. Capillarity-based preparation system for optical colorimetric sensor arrays

    Science.gov (United States)

    Luo, Xiao-gang; Yi, Xin; Bu, Xiang-nan; Hou, Chang-jun; Huo, Dan-qun; Yang, Mei; Fa, Huan-bao; Lei, Jin-can

    2017-03-01

    In recent years, optical colorimetric sensor arrays have demonstrated beneficial features, including rapid response, high selectivity, and high specificity; as a result, it has been extensively applied in food inspection and chemical studies, among other fields. There are instruments in the current market available for the preparation of an optical colorimetric sensor array, but it lacks the corresponding research of the preparation mechanism. Therefore, in connection with the main features of this kind of sensor array such as consistency, based on the preparation method of contact spotting, combined with a capillary fluid model, Washburn equation, Laplace equation, etc., this paper develops a diffusion model of an optical colorimetric sensor array during its preparation and sets up an optical colorimetric sensor array preparation system based on this diffusion model. Finally, this paper compares and evaluates the sensor arrays prepared by the system and prepared manually in three aspects such as the quality of array point, response of array, and response result, and the results show that the performance index of the sensor array prepared by a system under this diffusion model is better than that of the sensor array of manual spotting, which meets the needs of the experiment.

  7. Capillarity-based preparation system for optical colorimetric sensor arrays.

    Science.gov (United States)

    Luo, Xiao-Gang; Yi, Xin; Bu, Xiang-Nan; Hou, Chang-Jun; Huo, Dan-Qun; Yang, Mei; Fa, Huan-Bao; Lei, Jin-Can

    2017-03-01

    In recent years, optical colorimetric sensor arrays have demonstrated beneficial features, including rapid response, high selectivity, and high specificity; as a result, it has been extensively applied in food inspection and chemical studies, among other fields. There are instruments in the current market available for the preparation of an optical colorimetric sensor array, but it lacks the corresponding research of the preparation mechanism. Therefore, in connection with the main features of this kind of sensor array such as consistency, based on the preparation method of contact spotting, combined with a capillary fluid model, Washburn equation, Laplace equation, etc., this paper develops a diffusion model of an optical colorimetric sensor array during its preparation and sets up an optical colorimetric sensor array preparation system based on this diffusion model. Finally, this paper compares and evaluates the sensor arrays prepared by the system and prepared manually in three aspects such as the quality of array point, response of array, and response result, and the results show that the performance index of the sensor array prepared by a system under this diffusion model is better than that of the sensor array of manual spotting, which meets the needs of the experiment.

  8. Autonomous chemical and biological miniature wireless-sensor

    Science.gov (United States)

    Goldberg, Bar-Giora

    2005-05-01

    would take place within the miniature, low cost distributed sensor platforms. This concept however presents a significant challenge due to a combination and convergence of required new technologies, as mentioned above. Passive biological and chemical sensors with very high sensitivity and which require no assaying are in development using a technique to optically and chemically encode silicon wafers with tailored nanostructures. The silicon wafer is patterned with nano-structures designed to change colors ad patterns when exposed to the target analytes (TICs, TIMs, VOC). A small video camera detects the color and pattern changes on the sensor. To determine if an alarm condition is present, an on board DSP processor, using specialized image processing algorithms and statistical analysis, determines if color gradient changes occurred on the sensor array. These sensors can detect several agents simultaneously. This system is currently under development by Avaak, with funding from DARPA through an SBIR grant.

  9. Polymers for Chemical Sensors Using Hydrosilylation Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Kaganove, Steven N.; Nelson, David A.

    2001-06-28

    Sorbent and functionalized polymers play a key role in a diverse set of fields, including chemical sensors, separation membranes, solid phase extraction techniques, and chromatography. Sorbent polymers are critical to a number of sensor array or "electronic nose" systems. The responses of the sensors in the array give rise to patterns that can be used to distinguish one compound from another, provided that a sufficiently diverse set of sensing materials is present in the array. Figure 1 illustrates the concept of several sensors, each with a different sensor coating, giving rise to variable responses to an analyte that appear as a pattern in bar graph format. Using hydrosilylation as the bond-forming reaction, we have developed a versatile and efficient approach to developing sorbent polymers with diverse interactive properties for sensor applications. Both the chemical and physical properties of these polymers are predictable and tunable by design.

  10. Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

    Science.gov (United States)

    Hunter, Gary W.

    2005-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, and fire detection. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors; 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity; 3) The development of high temperature semiconductors, especially silicon carbide. This presentation discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  11. Coordinated sensor cueing for chemical plume detection

    Science.gov (United States)

    Abraham, Nathan J.; Jensenius, Andrea M.; Watkins, Adam S.; Hawthorne, R. Chad; Stepnitz, Brian J.

    2011-05-01

    This paper describes an organic data fusion and sensor cueing approach for Chemical, Biological, Radiological, and Nuclear (CBRN) sensors. The Joint Warning and Reporting Network (JWARN) uses a hardware component referred to as the JWARN Component Interface Device (JCID). The Edgewood Chemical and Biological Center has developed a small footprint and open architecture solution for the JCID capability called JCID-on-a-Chip (JoaC). The JoaC program aims to reduce the cost and complexity of the JCID by shrinking the necessary functionality down to a small single board computer. This effort focused on development of a fusion and cueing algorithm organic to the JoaC hardware. By embedding this capability in the JoaC, sensors have the ability to receive and process cues from other sensors without the use of a complex and costly centralized infrastructure. Additionally, the JoaC software is hardware agnostic, as evidenced by its drop-in inclusion in two different system-on-a-chip platforms including Windows CE and LINUX environments. In this effort, a partnership between JPM-CA, JHU/APL, and the Edgewood Chemical and Biological Center (ECBC), the authors implemented and demonstrated a new algorithm for cooperative detection and localization of a chemical agent plume. This experiment used a pair of mobile Joint Services Lightweight Standoff Chemical Agent Detector (JSLSCAD) units which were controlled by fusion and cueing algorithms hosted on a JoaC. The algorithms embedded in the JoaC enabled the two sensor systems to perform cross cueing and cooperatively form a higher fidelity estimate of chemical releases by combining sensor readings. Additionally, each JSLSCAD had the ability to focus its search on smaller regions than those required by a single sensor system by using the cross cue information from the other sensor.

  12. Miniaturised optical sensors for industrial applications

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Hanson, Steen Grüner

    2010-01-01

    When addressing optical sensors for use in e.g. industry, compactness, robustness and performance are essentials. Adhering to these demands, we have developed a suit of compact optical sensors for the specific purposes of measuring angular velocity and linear translations of rigid objects....... The technology is based on compact and low-cost laser sources such as Vertical Cavity Surface Emitting Lasers (VCSELs). The methods characterise the object motion by speckle translation in the near field (imaging) or far field (optical Fourier transform) by optical spatial filtering velocimetry. The volume...

  13. Fiber optic sensors for environmental applications: A brief review

    Energy Technology Data Exchange (ETDEWEB)

    Rossabi, J.

    1992-04-01

    Understanding the flow a groundwater quality. This understanding is achieved by measurement of the appropriate chemical and physical subsurface parameters. The ideal measurement would accurately assess a parameter without affecting the parameter or its environment. Fiber optic spectroscopy offers some of the most promising techniques for accurate, non-invasive measurements of environmental parameters. Fiber optic sensors for subsurface applications are currently being developed by several Department of Energy laboratories. Some of these sensors have been successfully deployed in the field and are attaining the goals of accurate, noninvasive, real time measurements in the subsurface.

  14. Surface Plasmon Resonance Sensors Based on Polymer Optical Fiber

    Institute of Scientific and Technical Information of China (English)

    Rong-Sheng Zheng; Yong-Hua Lu; Zhi-Guo Xie; Jun Tao; Kai-Qun Lin; Hai Ming

    2008-01-01

    Surface Plasmon Resonance (SPR) is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering (SERS) probe.Long-period fiber gratings are fabricated on single mode polymer optical fiber (POF) with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.

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

    Science.gov (United States)

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

    2015-07-01

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

  16. Fiber-optic sensor applications in civil and geotechnical engineering

    Science.gov (United States)

    Habel, Wolfgang R.; Krebber, Katerina

    2011-09-01

    Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state (pH value) of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission (AE) sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating (FBG) sensors attached to anchor steels (micro piles) to measure the strain distribution in loaded soil anchors. Polymer optical fibers (POF) can be — because of their high elasticity and high ultimate strain — well integrated into textiles to monitor their deformation behaviour. Such "intelligent" textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures (dikes, dams, and embankments) as well as in masonry structures during and after earthquakes.

  17. Optical sensors for harsh environment applications

    Science.gov (United States)

    Sharma, R.; Maity, S.; Bekal, A.; Vartak, S.; Sridharan, A. K.; Mitra, C.

    2015-05-01

    The development of a harsh environment ammonia slip sensor based on tunable diode laser absorption spectroscopy is presented. A hybrid optical sensor design, through combination of wavelength modulation spectroscopy (WMS) and alignment control, is proposed as an approach towards reliable in-situ measurements in misalignment prone harsh environments. 1531.59 nm, 1553.4 nm and 1555.56 nm are suggested as possible absorption lines for trace ammonia measurement (system are presented in detail. Effect of misalignment related measurement degradation is investigated and significant improvement in measurement fidelity is demonstrated through the use of the hybrid optical sensor design.

  18. Graphene Chemical Sensor for Heliophysics Applications

    Science.gov (United States)

    Sultana, Mahmooda; Herrero, Fred; Khazanov, George

    2013-01-01

    Graphene is a single layer of carbon atoms that offer a unique set of advantages as a chemical sensor due to a number of its inherent properties. Graphene has been explored as a gas sensor for a variety of gases, and molecular sensitivity has been demonstrated by measuring the change in electrical properties due to the adsorption of target species. In this paper, we discuss the development of an array of chemical sensors based on graphene and its relevance to plasma physics due to its sensitivity to radical species such as oxonium, hydron and the corresponding neutrals. We briefly discuss the great impact such sensors will have on a number of heliophysics applications such as ground-based manifestations of space weather.

  19. Graphene chemical sensors for heliophysics applications

    Science.gov (United States)

    Sultana, Mahmooda; Herrero, Fred; Khazanov, George

    2013-10-01

    Graphene is a single layer of carbon atoms that offer a unique set of advantages as a chemical sensor due to a number of its inherent properties. Graphene has been explored as a gas sensor for a variety of gases, and molecular sensitivity has been demonstrated by measuring the change in electrical properties due to the adsorption of target species (Schedin, F.; Geim, A.K.; Morozov, S.V.; Hill, E.W.; Blake, P.; Katsnelson, M.I.; Novoselov, K.S. Nat. Mater 2007, 6, 652-655. doi:10.1038/nmat1967). In this paper, we discuss the development of an array of chemical sensors based on graphene and its relevance to plasma physics due to its sensitivity to radical species such as O+, H+ and the corresponding neutrals. We briefly discuss the great impact such sensors will have on a number of heliophysics applications such as ground-based manifestations of space weather.

  20. Dynamic temperature measurements with embedded optical sensors.

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

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

  1. Micromachined chemical sensor with integrated microelectronics

    Science.gov (United States)

    Smith, J.; Sniegowski, J.; Koehler, D.; Ricco, T.; Martin, S.; McWhorter, P.

    With today's continued emphasis on environmental safety and health issues, a resurgence of interest has developed in the area of chemical sensors. These sensors would typically be used to monitor contamination hazards such as underground storage tanks or to assess previous contamination at waste disposal sites. Human exposure to chemical hazards can also be monitored. Additionally, these sensors can be used as part of a manufacturing process control loop. One type of sensor suitable for gas phase monitoring of chemicals is the quartz resonator or quartz crystal microbalance (QCM) sensor. In this type of sensor, a thickness shear mode (TSM) quartz resonator is coated with a film that interacts with the chemical species of interest. Changes in the mass and elasticity of this film are reflected as changes in the resonant properties of the device. Therefore, the presence of the species of interest can be detected by monitoring the frequency of an oscillator based on the resonance of the quartz. These QCM sensors compete with surface acoustic wave (SAW) devices as a means for monitoring gas phase species. SAW devices are typically more sensitive to small amounts of a species, but the instrumentation associated with a SAW device is an order of magnitude more expensive than the instrumentation associated with a TSM wave resonator since the SAW devices operate in the 100's of MHz frequency regime while quartz resonators operate in the 5-25 MHz regime. We are working to improve the sensitivity of the QCM sensor by increasing the frequency of the device to 25 MHz (compared to the typical 5 MHz crystal) and by increasing the frequency stability of the system to an ultimate goal of 0.1 Hz. The 25 MHz QCM has already been achieved, and once the stability goal is achieved, the QCM will have the same sensitivity as a SAW device.

  2. SAW Sensors for Chemical Vapors and Gases.

    Science.gov (United States)

    Devkota, Jagannath; Ohodnicki, Paul R; Greve, David W

    2017-04-08

    Surface acoustic wave (SAW) technology provides a sensitive platform for sensing chemicals in gaseous and fluidic states with the inherent advantages of passive and wireless operation. In this review, we provide a general overview on the fundamental aspects and some major advances of Rayleigh wave-based SAW sensors in sensing chemicals in a gaseous phase. In particular, we review the progress in general understanding of the SAW chemical sensing mechanism, optimization of the sensor characteristics, and the development of the sensors operational at different conditions. Based on previous publications, we suggest some appropriate sensing approaches for particular applications and identify new opportunities and needs for additional research in this area moving into the future.

  3. Carbon nanotubes as optical biomedical sensors.

    Science.gov (United States)

    Kruss, Sebastian; Hilmer, Andrew J; Zhang, Jingqing; Reuel, Nigel F; Mu, Bin; Strano, Michael S

    2013-12-01

    Biosensors are important tools in biomedical research. Moreover, they are becoming an essential part of modern healthcare. In the future, biosensor development will become even more crucial due to the demand for personalized-medicine, point-of care devices and cheaper diagnostic tools. Substantial advances in sensor technology are often fueled by the advent of new materials. Therefore, nanomaterials have motivated a large body of research and such materials have been implemented into biosensor devices. Among these new materials carbon nanotubes (CNTs) are especially promising building blocks for biosensors due to their unique electronic and optical properties. Carbon nanotubes are rolled-up cylinders of carbon monolayers (graphene). They can be chemically modified in such a way that biologically relevant molecules can be detected with high sensitivity and selectivity. In this review article we will discuss how carbon nanotubes can be used to create biosensors. We review the latest advancements of optical carbon nanotube based biosensors with a special focus on near-infrared (NIR)-fluorescence, Raman-scattering and fluorescence quenching.

  4. Proliferation detection using a remote resonance Raman chemical sensor

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A.J.; Chen, C.L.; Dougherty, D.R.

    1993-08-01

    The authors discussed the potential of the resonance Raman chemical sensor as a remote sensor that can be used for gases, liquids or solids. This spectroscopy has the fundamental advantage that it is based on optical fingerprints that are insensitive to environmental perturbations or excitation frequency. By taking advantage of resonance enhancement, the inelastic scattering cross-section can increase anywhere from 4 to 6 orders of magnitude which translates into increased sensing range or lower detection limits. It was also shown that differential cross-sections as small as 10{sup {minus}27} cm{sup 2}/sr do not preclude the use of this technique as being an important component in one`s remote-sensing arsenal. The results obtained in the early 1970s on various pollutants and the more recent work on atmospheric water cast a favorable light on the prospects for the successful development of a resonance Raman remote sensor. Currently, of the 20 CW agent-related {open_quotes}signature{close_quotes} chemicals that the authors have investigated, 18 show enhancements ranging from 3 to 6 orders of magnitude. The absolute magnitudes of the measured resonance enhanced Raman cross-sections for these 18 chemicals suggest that detection and identification of trace quantities of the {open_quotes}signature{close_quotes} chemicals, through a remote resonance Raman chemical sensor, could be achieved.

  5. Chemical sensors technology development planning workshop

    Energy Technology Data Exchange (ETDEWEB)

    Bastiaans, G.J.; Haas, W.J. Jr.; Junk, G.A. [eds.

    1993-03-01

    The workshop participants were asked to: (1) Assess the current capabilities of chemical sensor technologies for addressing US Department of Energy (DOE) Environmental Restoration and Waste Management (EM) needs; (2) Estimate potential near term (one to two years) and intermediate term (three to five years) capabilities for addressing those needs; and (3) Generate a ranked list of specific recommendations on what research and development (R&D) should be funded to provide the necessary capabilities. The needs were described in terms of two pervasive EM problems, the in situ determination of chlorinated volatile organic compounds (VOCs), and selected metals in various matrices at DOE sites. The R&D recommendations were to be ranked according to the estimated likelihood that the product technology will be ready for application within the time frame it is needed and the estimated return on investment. The principal conclusions and recommendations of the workshop are as follows: Chemical sensors capable of in situ determinations can significantly reduce analytical costs; Chemical sensors have been developed for certain VOCs in gases and water but none are currently capable of in situ determination of VOCs in soils; The DOE need for in situ determination of metals in soils cannot be addressed with existing chemical sensors and the prospects for their availability in three to five years are uncertain; Adaptation, if necessary, and field application of laboratory analytical instruments and those few chemical sensors that are already in field testing is the best approach for the near term; The chemical sensor technology development plan should include balanced support for near- and intermediate-term efforts.

  6. Optical Fibre Pressure Sensors in Medical Applications

    Directory of Open Access Journals (Sweden)

    Sven Poeggel

    2015-07-01

    Full Text Available This article is focused on reviewing the current state-of-the-art of optical fibre pressure sensors for medical applications. Optical fibres have inherent advantages due to their small size, immunity to electromagnetic interferences and their suitability for remote monitoring and multiplexing. The small dimensions of optical fibre-based pressure sensors, together with being lightweight and flexible, mean that they are minimally invasive for many medical applications and, thus, particularly suited to in vivo measurement. This means that the sensor can be placed directly inside a patient, e.g., for urodynamic and cardiovascular assessment. This paper presents an overview of the recent developments in optical fibre-based pressure measurements with particular reference to these application areas.

  7. Nanostructured conjugated polymers in chemical sensors: synthesis, properties and applications.

    Science.gov (United States)

    Correa, D S; Medeiros, E S; Oliveira, J E; Paterno, L G; Mattoso, Luiz C

    2014-09-01

    Conjugated polymers are organic materials endowed with a π-electron conjugation along the polymer backbone that present appealing electrical and optical properties for technological applications. By using conjugated polymeric materials in the nanoscale, such properties can be further enhanced. In addition, the use of nanostructured materials makes possible miniaturize devices at the micro/nano scale. The applications of conjugated nanostructured polymers include sensors, actuators, flexible displays, discrete electronic devices, and smart fabric, to name a few. In particular, the use of conjugated polymers in chemical and biological sensors is made feasible owning to their sensitivity to the physicochemical conditions of its surrounding environment, such as chemical composition, pH, dielectric constant, humidity or even temperature. Subtle changes in these conditions bring about variations on the electrical (resistivity and capacitance), optical (absorptivity, luminescence, etc.), and mechanical properties of the conjugated polymer, which can be precisely measured by different experimental methods and ultimately associated with a specific analyte and its concentration. The present review article highlights the main features of conjugated polymers that make them suitable for chemical sensors. An especial emphasis is given to nanostructured sensors systems, which present high sensitivity and selectivity, and find application in beverage and food quality control, pharmaceutical industries, medical diagnosis, environmental monitoring, and homeland security, and other applications as discussed throughout this review.

  8. Optical Imaging Sensors and Systems for Homeland Security Applications

    CERN Document Server

    Javidi, Bahram

    2006-01-01

    Optical and photonic systems and devices have significant potential for homeland security. Optical Imaging Sensors and Systems for Homeland Security Applications presents original and significant technical contributions from leaders of industry, government, and academia in the field of optical and photonic sensors, systems and devices for detection, identification, prevention, sensing, security, verification and anti-counterfeiting. The chapters have recent and technically significant results, ample illustrations, figures, and key references. This book is intended for engineers and scientists in the relevant fields, graduate students, industry managers, university professors, government managers, and policy makers. Advanced Sciences and Technologies for Security Applications focuses on research monographs in the areas of -Recognition and identification (including optical imaging, biometrics, authentication, verification, and smart surveillance systems) -Biological and chemical threat detection (including bios...

  9. Uncoated microcantilevers as chemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Thundat, Thomas G. (Knoxville, TN)

    2001-01-01

    A method and device are provided for chemical sensing using cantilevers that do not use chemically deposited, chemically specific layers. This novel device utilizes the adsorption-induced variation in the surfaces states on a cantilever. The methodology involves exciting charge carriers into or out of the surface states with photons having increasing discrete levels of energy. The excitation energy is provided as discrete levels of photon energy by scanning the wavelength of an exciting source that is illuminating the cantilever surface. When the charge carriers are excited into or out of the surface states, the cantilever bending changes due to changes in surface stress. The amount of cantilever bending with respect to an identical cantilever as a function of excitation energy is used to determine the energy levels associated with adsorbates.

  10. Hybrid Piezoelectric/Fiber-Optic Sensor Sheets

    Science.gov (United States)

    Lin, Mark; Qing, Xinlin

    2004-01-01

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

  11. Optical network of silicon micromachined sensors

    Science.gov (United States)

    Wilson, Mark L.; Burns, David W.; Zook, J. David

    1996-03-01

    The Honeywell Technology Center, in collaboration with the University of Wisconsin and the Mobil Corporation, and under funding from this ARPA sponsored program, are developing a new type of `hybrid' micromachined silicon/fiber optic sensor that utilizes the best attributes of each technology. Fiber optics provide a noise free method to read out the sensor without electrical power required at the measurement point. Micromachined silicon sensor techniques provide a method to design many different types of sensors such as temperature, pressure, acceleration, or magnetic field strength and report the sensor data using FDM methods. Our polysilicon resonant microbeam structures have a built in Fabry-Perot interferometer that offers significant advantages over other configurations described in the literature. Because the interferometer is an integral part of the structure, the placement of the fiber becomes non- critical, and packaging issues become considerably simpler. The interferometer spacing are determined by the thin-film fabrication processes and therefore can be extremely well controlled. The main advantage, however, is the integral vacuum cavity that ensures high Q values. Testing results have demonstrated relaxed alignment tolerances in packaging these devices, with an excellent Signal to Noise Ratio. Networks of 16 or more sensors are currently being developed. STORM (Strain Transduction by Optomechanical Resonant Microbeams) sensors can also provide functionality and self calibration information which can be used to improve the overall system reliability. Details of the sensor and network design, as well as test results, are presented.

  12. Wide-Area Chemical Sensor

    Science.gov (United States)

    2014-11-01

    2014www.ll.mit.edu The detection and localization of gas releases such as methane from leaking natural gas pipelines or nitrogen oxides from failing electrical...reference gas cells, such as methane buffered by nitro- gen, and a low-concentration gas cell that contains the target species to calibrate the...self-referencing technique employed by WACS is particularly suited to detecting chemical agents composed of primarily small molecules— methane , various

  13. All-Optical Graphene Oxide Humidity Sensors

    Directory of Open Access Journals (Sweden)

    Weng Hong Lim

    2014-12-01

    Full Text Available The optical characteristics of graphene oxide (GO were explored to design and fabricate a GO-based optical humidity sensor. GO film was coated onto a SU8 polymer channel waveguide using the drop-casting technique. The proposed sensor shows a high TE-mode absorption at 1550 nm. Due to the dependence of the dielectric properties of the GO film on water content, this high TE-mode absorption decreases when the ambient relative humidity increases. The proposed sensor shows a rapid response (<1 s to periodically interrupted humid air flow. The transmission of the proposed sensor shows a linear response of 0.553 dB/% RH in the range of 60% to 100% RH.

  14. High-sensitivity fiber optic acoustic sensors

    Science.gov (United States)

    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.

  15. Electrostatic thin film chemical and biological sensor

    Science.gov (United States)

    Prelas, Mark A.; Ghosh, Tushar K.; Tompson, Jr., Robert V.; Viswanath, Dabir; Loyalka, Sudarshan K.

    2010-01-19

    A chemical and biological agent sensor includes an electrostatic thin film supported by a substrate. The film includes an electrostatic charged surface to attract predetermined biological and chemical agents of interest. A charge collector associated with said electrostatic thin film collects charge associated with surface defects in the electrostatic film induced by the predetermined biological and chemical agents of interest. A preferred sensing system includes a charge based deep level transient spectroscopy system to read out charges from the film and match responses to data sets regarding the agents of interest. A method for sensing biological and chemical agents includes providing a thin sensing film having a predetermined electrostatic charge. The film is exposed to an environment suspected of containing the biological and chemical agents. Quantum surface effects on the film are measured. Biological and/or chemical agents can be detected, identified and quantified based on the measured quantum surface effects.

  16. Thermal strain analysis of optic fiber sensors.

    Science.gov (United States)

    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.

  17. Photonic crystal fiber based chloride chemical sensors for corrosion monitoring

    Science.gov (United States)

    Wei, Heming; Tao, Chuanyi; Krishnaswamy, Sridhar

    2016-04-01

    Corrosion of steel is one of the most important durability issues in reinforced concrete (RC) structures because aggressive ions such as chloride ions permeate concrete and corrode steel, consequently accelerating the destruction of structures, especially in marine environments. There are many practical methods for corrosion monitoring in RC structures, mostly focusing on electrochemical-based sensors for monitoring the chloride ion which is thought as one of the most important factors resulting in steel corrosion. In this work, we report a fiber-optic chloride chemical sensor based on long period gratings inscribed in a photonic crystal fiber (PCF) with a chloride sensitive thin film. Numerical simulation is performed to determine the characteristics and resonance spectral response versus the refractive indices of the analyte solution flowing through into the holes in the PCF. The effective refractive index of the cladding mode of the LPGs changes with variations of the analyte solution concentration, resulting in a shift of the resonance wavelength, hence providing the sensor signal. This fiber-optic chemical sensor has a fast response, is easy to prepare and is not susceptible to electromagnetic environment, and can therefore be of use for structural health monitoring of RC structures subjected to such aggressive environments.

  18. Fiber Optic Sensors For Detection of Toxic and Biological Threats

    Directory of Open Access Journals (Sweden)

    Jianming Yuan

    2007-12-01

    Full Text Available Protection of public and military personnel from chemical and biological warfareagents is an urgent and growing national security need. Along with this idea, we havedeveloped a novel class of fiber optic chemical sensors, for detection of toxic and biologicalmaterials. The design of these fiber optic sensors is based on a cladding modificationapproach. The original passive cladding of the fiber, in a small section, was removed and thefiber core was coated with a chemical sensitive material. Any change in the opticalproperties of the modified cladding material, due to the presence of a specific chemicalvapor, changes the transmission properties of the fiber and result in modal powerredistribution in multimode fibers. Both total intensity and modal power distribution (MPDmeasurements were used to detect the output power change through the sensing fibers. TheMPD technique measures the power changes in the far field pattern, i.e. spatial intensitymodulation in two dimensions. Conducting polymers, such as polyaniline and polypyrrole,have been reported to undergo a reversible change in conductivity upon exposure tochemical vapors. It is found that the conductivity change is accompanied by optical propertychange in the material. Therefore, polyaniline and polypyrrole were selected as the modifiedcladding material for the detection of hydrochloride (HCl, ammonia (NH3, hydrazine(H4N2, and dimethyl-methl-phosphonate (DMMP {a nerve agent, sarin stimulant},respectively. Several sensors were prepared and successfully tested. The results showeddramatic improvement in the sensor sensitivity, when the MPD method was applied. In thispaper, an overview on the developed class of fiber optic sensors is presented and supportedwith successful achieved results.

  19. Optical Landing Hazard Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Visidyne's Phase I effort has established through modeling and analysis that a unique concept for an active optical 3-D Imager (or Imaging LADAR) has high potential...

  20. Miniaturised Optical Fibre Sensor for Dew Detection Inside Organ Pipes

    OpenAIRE

    Francesco Baldini; Riccardo Falciai; Andrea Azelio Mencaglia; Folco Senesi; Dario Camuffo; Antonio della Valle; Carl Johan Bergsten

    2008-01-01

    A new optical sensor for the continuous monitoring of the dew formation inside organ pipes was designed. This aspect is particularly critical for the conservation of organs in unheated churches since the dew formation or the condensation on the pipe surfaces can contribute to many kinds of physical and chemical disruptive mechanisms. The working principle is based on the change in the reflectivity which is observed on the surface of the fibre tip, when a water layer is formed on its distal en...

  1. Miniaturized optical sensors based on lens arrays

    DEFF Research Database (Denmark)

    Hanson, Steen Grüner; Jakobsen, M.L.; Larsen, H.E.

    2005-01-01

    A suite of optical sensors based on the use of lenticular arrays for probing mechanical deflections will be displayed. The optical systems are well suited for miniaturization, and utilize speckles as the information-carriers. This implementation allows for acquiring directional information of the...... of the displacement. Systems for probing lateral displacements and in-plane vibrations (1-D and 2-D) are displayed, as will systems for probing angular velocity and torsional vibrations of rotating objects....

  2. Conducting polymers in electronic chemical sensors.

    Science.gov (United States)

    Janata, Jiri; Josowicz, Mira

    2003-01-01

    Conducting organic polymers have found two main kinds of application in electronics so far: as materials for construction of various devices and as selective layers in chemical sensors. In either case, interaction with ambient gases is critical. It may compromise the performance of a device based on conducting polymers, whereas it is beneficial in a sensor. Conductivity has been the primary property of interest. Work function--related to conductivity, but in principle a different property--has received only scant attention. Our aim here is to discuss the usability of conducting polymers in both types of electronic applications in light of these two parameters.

  3. Modeling Microscopic Chemical Sensors in Capillaries

    CERN Document Server

    Hogg, Tad

    2008-01-01

    Nanotechnology-based microscopic robots could provide accurate in vivo measurement of chemicals in the bloodstream for detailed biological research and as an aid to medical treatment. Quantitative performance estimates of such devices require models of how chemicals in the blood diffuse to the devices. This paper models microscopic robots and red blood cells (erythrocytes) in capillaries using realistic distorted cell shapes. The models evaluate two sensing scenarios: robots moving with the cells past a chemical source on the vessel wall, and robots attached to the wall for longer-term chemical monitoring. Using axial symmetric geometry with realistic flow speeds and diffusion coefficients, we compare detection performance with a simpler model that does not include the cells. The average chemical absorption is quantitatively similar in both models, indicating the simpler model is an adequate design guide to sensor performance in capillaries. However, determining the variation in forces and absorption as cells...

  4. Engineering materials for mid-infrared optical sensor applications

    Directory of Open Access Journals (Sweden)

    Richardson K. A

    2013-11-01

    Full Text Available Planar optical structures based on functionalized chalcogenide glasses provide a superb device platform for chemical and biological sensing applications. Chalcogenide glasses have demonstrated promise as materials for infrared sensing as they exhibit transparency over a large range of infrared wavelengths and tunable optical properties through doping and/or compositional tailoring. Waveguides, resonators and other components processed on-chip (silicon, Si can be realized such that the strong enhancement in the electromagnetic field confined within a high index contrast resonator, leads to highly sensitive photon-matter interactions in a small footprint. In this paper we discuss the development of highly sensitive chalcogenide glass based microdisk resonator sensors that measure resonant peak shifts caused by refractive index change upon exposure to a chemical analyte. The specificity of the microdisk resonator sensors is enhanced by applying specialized polymer films and nanofoams that respond in a predictable fashion when exposed to a chemical analyte of interest. Discussed are key material science challenges needed to enable highly sensitive and specific sensors based on such complex multi-material assemblies and the fabrication issues that ultimately define resulting optical performance.

  5. Monolithic integrated optic fiber Bragg grating sensor interrogator

    Science.gov (United States)

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

    2010-04-01

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

  6. Measuring method for optical fibre sensors

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Fluitman, J.H.J.

    1984-01-01

    A new measuring method for the signal amplitude in intensity modulating fibre optic sensors is described. A reference signal is generated in the time domain. The method is insensitive for the sensitivity fluctuations of the light transmitter and the light receiver. The method is experimentally

  7. Integrated Optical Asymmetric Coupler Pressure Sensor

    Science.gov (United States)

    Kiyat, Isa; Kocabas, Coskun; Aydinli, Atilla

    2004-05-01

    Analysis of a novel pressure sensor based on a silicon-on-insulator (SOI) asymmetric vertical coupler is presented. The integrated optical component is a coupler composed of a single mode (SM) low index waveguide and a thin silicon slab. High sensitivities of about 0.14 rad.kPa-1 should be achieved.

  8. Measuring method for optical fibre sensors

    NARCIS (Netherlands)

    Lammerink, T.S.J.; Fluitman, J.H.J.

    1984-01-01

    A new measuring method for the signal amplitude in intensity modulating fibre optic sensors is described. A reference signal is generated in the time domain. The method is insensitive for the sensitivity fluctuations of the light transmitter and the light receiver. The method is experimentally teste

  9. The development of fibre optic microbend sensors

    NARCIS (Netherlands)

    Horsthuis, W.H.G.; Fluitman, J.H.J.

    1983-01-01

    Investigations concerning the development of a fibre optic pressure sensor are reported. The phenomenon of light power attenuation in a periodically deformed graded index fibre has been studied theoretically. It appears that available theories are not suited to describe this attenuation process in t

  10. Compact optical MEMS accelerometers and temperature sensors

    Science.gov (United States)

    Timotijevic, Branislav; Petremand, Yves; Bayat, Dara; Luetzelschwab, Markus; Aebi, Laurent; Tormen, Maurizio

    2017-02-01

    Continuous and accurate monitoring of acceleration and temperature inside large turbo- and hydro-generators is of crucial importance to prevent extremely expensive system damages and false positives. Development of optical, metalfree sensors for such systems has gained a lot of attention due to the fact that they are resistant to typically very strong electromagnetic fields and that they are non-conductive. We present miniature temperature and accelerometer optical sensors using a common silicon MEMS platform. A linear response with a deviation as small as 1% between set and measured accelerations has been obtained in an acceleration range 0-40g. Preliminary tests for temperature sensors indicate a linear response with sensitivity better than 1°C in a range of 20°C to 150°C.

  11. Biomimetic chemical sensors using bioengineered olfactory and taste cells

    OpenAIRE

    Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

    2014-01-01

    Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing ...

  12. Graphene-Based Chemical Vapor Sensors for Electronic Nose Applications

    Science.gov (United States)

    Nallon, Eric C.

    An electronic nose (e-nose) is a biologically inspired device designed to mimic the operation of the olfactory system. The e-nose utilizes a chemical sensor array consisting of broadly responsive vapor sensors, whose combined response produces a unique pattern for a given compound or mixture. The sensor array is inspired by the biological function of the receptor neurons found in the human olfactory system, which are inherently cross-reactive and respond to many different compounds. The use of an e-nose is an attractive approach to predict unknown odors and is used in many fields for quantitative and qualitative analysis. If properly designed, an e-nose has the potential to adapt to new odors it was not originally designed for through laboratory training and algorithm updates. This would eliminate the lengthy and costly R&D costs associated with materiel and product development. Although e-nose technology has been around for over two decades, much research is still being undertaken in order to find new and more diverse types of sensors. Graphene is a single-layer, 2D material comprised of carbon atoms arranged in a hexagonal lattice, with extraordinary electrical, mechanical, thermal and optical properties due to its 2D, sp2-bonded structure. Graphene has much potential as a chemical sensing material due to its 2D structure, which provides a surface entirely exposed to its surrounding environment. In this configuration, every carbon atom in graphene is a surface atom, providing the greatest possible surface area per unit volume, so that electron transport is highly sensitive to adsorbed molecular species. Graphene has gained much attention since its discovery in 2004, but has not been realized in many commercial electronics. It has the potential to be a revolutionary material for use in chemical sensors due to its excellent conductivity, large surface area, low noise, and versatile surface for functionalization. In this work, graphene is incorporated into a

  13. OPUS: an optically parallel ultrasound sensor

    Science.gov (United States)

    Kallman, Jeffrey S.; Ashby, A. E.; Ciarlo, Dino R.; Thomas, Graham H.

    2000-03-01

    Transmission ultrasound is not in widespread use, partially because of the time and expense of acquiring the data. We are addressing this problem with an optically parallel ultrasound sensor. The core of the sensor is a thin silicon nitride membrane patterned with gold to create 'acoustic pixels' over a large area. Each acoustic pixel vibrates at the frequency of the acoustic excitation. The thin membrane, supported by short walls over an optical substrate, with one side immersed in the ultrasound medium and the supported side exposed to air, flexes when an ultrasound pressure wave encounters it. This flexing causes the air gap between the optical substrate and the membrane to change. The change in the air gap modulates the reflection of an optical beam by frustrated total internal reflection. By strobing the optical beam, the deflection of the membrane can be detected and measured at any point through the acoustic period. Acquiring a sequence of images allow us to extract the relative pressure phase and amplitude. Proof of principle experiments have shown that we can build this sensor, and we are currently using a small aperture version to examine simple test objects.

  14. Fibre optic sensor with disturbance localization in one optical fibre

    Science.gov (United States)

    Zyczkowski, M.; Ciurapinski, W.

    2007-05-01

    Ordinary perimeter security systems consist of many individual sensors with detection range 200-300 meters. These limitations are connected with physical phenomena that are used in microwave and infrared barriers as well as in ground and fence cable sensors. On the contrary, fiber optic perimeter sensors can be applied in the range of many kilometers and zone length 200-300 meters is degradation of their possibilities. This paper presents investigation results of a new generation of the fiber optic perimeter sensor in a two Sagnac and Sagna'c interferometers configuration. This system can detect a potential intruder and determine its position along a protected zone. We propose a method that makes use of the inherent properties of both interferometers. After demodulation of signals from both interferometers, obtained amplitude characteristic of the Sagnac interferometer depends on position of a disturbance along the both interferometer. So, quotient of both demodulated characteristics is proportional to the position of the disturbance. Arrangement of a laboratory model of the sensor and its signal processing scheme is presented. During research of a laboratory model, it was possible to detect the position of the disturbance with resolution of about 50m along a 10-km long sensor.

  15. NOVEL SPECTRUM ABSORPTION OPTICAL FIBER METHANE SENSOR

    Institute of Scientific and Technical Information of China (English)

    Wang Shutao; Che Rensheng

    2005-01-01

    Based on spectrum principle and analyzing the infrared absorption spectrum of methane, a kind of optical fiber methane gas sensor and its system are developed. DFBLD(Distributed feedback laser diode) in 1 300 nm waveband is used as illuminant and phase-detecting technology is used to carry out harmonic wave detecting the concentration of methane. The sensitivity can arrive at 10-5.Experiments results show that the performance targets of the sensor such as sensitivity can basically satisfy the requests of methane detection.

  16. Absolute Measurement Fiber-optic Sensors in Large Structural Monitoring

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The security of civil engineering is an important task due to the economic, social and environmental significance. Compared with conventional sensors, the optical fiber sensors have their unique characteristics.Being durable, stable and insensitive to external perturbations,they are particular interesting for the long-term monitoring of civil structures.Focus is on absolute measurement optical fiber sensors, which are emerging from the monitoring large structural, including SOFO system, F-P optical fiber sensors, and fiber Bragg grating sensors. The principle, characteristic and application of these three kinds of optical fiber sensors are described together with their future prospects.

  17. Optical Fibre Sensors Using Graphene-Based Materials: A Review

    Science.gov (United States)

    Hernaez, Miguel; Zamarreño, Carlos R.; Melendi-Espina, Sonia; Bird, Liam R.; Mayes, Andrew G.; Arregui, Francisco J.

    2017-01-01

    Graphene and its derivatives have become the most explored materials since Novoselov and Geim (Nobel Prize winners for Physics in 2010) achieved its isolation in 2004. The exceptional properties of graphene have attracted the attention of the scientific community from different research fields, generating high impact not only in scientific journals, but also in general-interest newspapers. Optical fibre sensing is one of the many fields that can benefit from the use of these new materials, combining the amazing morphological, chemical, optical and electrical features of graphene with the advantages that optical fibre offers over other sensing strategies. In this document, a review of the current state of the art for optical fibre sensors based on graphene materials is presented. PMID:28098825

  18. Optical Fibre Sensors Using Graphene-Based Materials: A Review

    Directory of Open Access Journals (Sweden)

    Miguel Hernaez

    2017-01-01

    Full Text Available Graphene and its derivatives have become the most explored materials since Novoselov and Geim (Nobel Prize winners for Physics in 2010 achieved its isolation in 2004. The exceptional properties of graphene have attracted the attention of the scientific community from different research fields, generating high impact not only in scientific journals, but also in general-interest newspapers. Optical fibre sensing is one of the many fields that can benefit from the use of these new materials, combining the amazing morphological, chemical, optical and electrical features of graphene with the advantages that optical fibre offers over other sensing strategies. In this document, a review of the current state of the art for optical fibre sensors based on graphene materials is presented.

  19. Optical sensors of bulk refractive index using optical fiber resonators

    Science.gov (United States)

    Eryürek, M.; Karadag, Y.; Ghafoor, M.; Bavili, N.; Cicek, K.; Kiraz, A.

    2017-05-01

    Optical fiber resonator (OFR) sensor is presented for bulk liquid refractive index (RI) sensing. The sensing mechanism relies on the spectral shifts of whispering gallery modes (WGMs) of OFRs which are excited using a tapered fiber. OFR liquid RI sensor is fully characterized using water solutions of ethanol and ethylene glycol (EG). A good agreement is achieved between the analytical calculations and experimental results for both TE and TM polarizations. The detection limit for bulk RI is calculated to be between 2.7 - 4.7 × 10-5 refractive index unit (RIU). The OFR sensor provides a robust, easy-to-fabricate and sensitive liquid refractive index sensor which can be employed in lab-on-a-chip applications.

  20. Single-Crystal Sapphire Optical Fiber Sensor Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Pickrell, Gary [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States); Scott, Brian [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States); Wang, Anbo [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States); Yu, Zhihao [Virginia Polytechnic Inst. & State Univ., Blacksburg, VA (United States)

    2013-12-31

    facility in Terre Haute, Indiana. Due to business conditions at industrial partner and several logistical problems, this field test was not successful. An alternative high-temperature sensing system using sapphire wafer-based extrinsic Fabry-Perot interferometry was then developed as a significant improvement over the BPDI solution. From June 2006 to June 2008, three consecutive field tests were performed with the new sapphire wafer sensors at the TECO coal gasifier in Tampa, Florida. One of the sensors survived in the industrial coal gasifier for 7 months, over which time the existing thermocouples were replaced twice. The outcome of these TECO field tests suggests that the sapphire wafer sensor has very good potential to be commercialized. However packaging and sensor protection issues need additional development. During Phase III, several major improvements in the design and fabrication process of the sensor have been achieved through experiments and theoretical analysis. Studies on the property of the key components in the sensor head, including the sapphire fiber and sapphire wafer, were also conducted, for a better understanding of the sensor behavior. A final design based on all knowledge and experience has been developed, free of any issues encountered during the entire research. Sensors with this design performed well as expected in lab long-term tests, and were deployed in the sensing probe of the final coal-gasifier field test. Sensor packaging and protection was improved through materials engineering through testing of packaging designs in two blank probe packaging tests at Eastman Chemical in Kingsport, TN. Performance analysis of the blank probe packaging resulted in improve package designs culminating in a 3rd generation probe packaging utilized for the full field test of the sapphire optical sensor and materials designed sensor packaging.

  1. 海洋环境监测中的光纤化学/生物传感技术%Study on the Fiber Optic Chemical Sensors and Biosensors Applied to Monitoring for Environmental Contaminants in Seawater

    Institute of Scientific and Technical Information of China (English)

    庄峙厦; 李伟; 陈曦; 孙大海; 王小如

    2001-01-01

    Rapid and continuous detection of environmental contaminants in effluents and waterways is important for protecting natural environments and public health, and for managing waster treatment systems. Some novel circulatory system for on-line monitoring of dissolved oxygen, pH, humidity and pollutants that make use of fiber-optic chemical sensors and biosensors are presented. Some useful approach have been employing chemical and bioluminescent reporter systems that involve whole molecular probes and bioluminescent microbes which provide rapid and visible responses to dissolved oxygen, pH, humidity and the presence of harmful chemicals, including heavy metal ions and petrochemical industry waters. Coupling such chemical and biological detection systems with fiber-optic chemical sensors and biosensors for environmental monitoring combines rapid response times, low costs and improved reproducibility.%通过光纤溶解氧、pH、湿度等化学传感探头及发光菌水质毒性监测生物传感探头的研制,开发出了一类能用于环境监测的新型传感器.其创新之处在于传感探头的设计与包装,以及数种可逆性、选择性、稳定性、使用寿命、响应时间、灵敏度等响应特性具佳的化学及生物传感膜的配方和制作技术.利用这些技术,通过对光纤探头的设计与包装,可以实现在现场及实验室模拟条件下对样品的选择性检测.研制的传感器能广泛应用于海洋污染调查、内河水质评价、水产养殖、工矿企业水气排污自检等诸多方面.

  2. New fiber optic sensor: application to refractive index sensing

    Science.gov (United States)

    Meriaudeau, Fabrice; Wig, A. G.; Passian, A.; Ferrell, Trinidad L.

    2000-08-01

    Optical fibers are more and more used as chemical sensors. This is, mainly due to their low cost, and their high efficiency to work in harsh and remote environments. Many devices are based on thin film plasmon excitation where a metal coating is evaporated onto the core of an etched optical fiber. In this paper, a new sensor configuration is presented. Instead of exciting surface plasmon waves on a thin film, surface plasma waves are excited on metal islands. The fiber is coated with 3 layers of gold. Each layer is annealed before the next layer is evaporated onto it. this is done to avoid any light leakage, fact which was found on a prior version with only one gold coating. Different sets of fibers were tested and sensitive and reproducible results for liquid with refraction indices varying from 1.3 to 1.7 were obtained.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. Bioinspired optical sensors for unmanned aerial systems

    Science.gov (United States)

    Chahl, Javaan; Rosser, Kent; Mizutani, Akiko

    2011-04-01

    Insects are dependant on the spatial, spectral and temporal distributions of light in the environment for flight control and navigation. This paper reports on flight trials of implementations of insect inspired behaviors on unmanned aerial vehicles. Optical flow methods for maintaining a constant height above ground and a constant course have been demonstrated to provide navigation capabilities that are impossible using conventional avionics sensors. Precision control of height above ground and ground course were achieved over long distances. Other vision based techniques demonstrated include a biomimetic stabilization sensor that uses the ultraviolet and green bands of the spectrum, and a sky polarization compass. Both of these sensors were tested over long trajectories in different directions, in each case showing performance similar to low cost inertial heading and attitude systems. The behaviors demonstrate some of the core functionality found in the lower levels of the sensorimotor system of flying insects and shows promise for more integrated solutions in the future.

  5. Design of optics for compact star sensors

    Science.gov (United States)

    Xu, Minyi; Shi, Rongbao; Shen, Weimin

    2016-10-01

    In order to adapt to small size and low cost space platform such as mini-satellites, this paper studies the design of optics for compact star sensor. At first, the relationship between limiting magnitude and optical system specifications which includes field of view and entrance pupil diameter is analyzed, based on its Pyramid identification algorithm and signal-to-noise ratio requirement. The specifications corresponding to different limiting magnitude can be obtained after the detector is selected, and both of the complexity of optical lens and the size of baffle can be estimated. Then the range of the limiting magnitude can be determined for the miniaturization of the optical system. Taking STAR1000 CMOS detector as an example, the compact design of the optical system can be realized when the limiting magnitude is in the interval of 4.9Mv 5.5Mv. At last, the lens and baffle of a CMOS compact star sensor is optimally designed, of which length and weight is respectively 124 millimeters and 300 grams.

  6. An Optical Pressure Sensor Based on MEMS

    Institute of Scientific and Technical Information of China (English)

    Tong Zhang; Sheng Qiang; Frank Lewis; Yalin Wu; Xiaozhu Chi

    2006-01-01

    An optical fiber pressure sensor has been developed for the measurement in human body. The sensing element is possessed of a membrane structure, which is fabricated by micromachining. The fabrication process includes anisotropic wet etching on the silicon wafer. For the transmitting source and signal light, a multimode optical fiber 50/125 μm (core/clad) in diameter was used. The intensity of the light reflected back into the fiber varies with the membrane deflection, which is a function of pressure. The deflection of the membrane by applied pressure can be mathematically described.

  7. Phase sensor for solar adaptive-optics

    CERN Document Server

    Kellerer, Aglae

    2011-01-01

    Wavefront sensing in solar adaptive-optics is currently done with correlating Shack-Hartmann sensors, although the spatial- and temporal-resolutions of the phase measurements are then limited by the extremely fast computing required to correlate the sensor signals at the frequencies of daytime atmospheric-fluctuations. To avoid this limitation, a new wavefront-sensing technique is presented, that makes use of the solar brightness and is applicable to extended sources. The wavefront is sent through a modified Mach-Zehnder interferometer. A small, central part of the wavefront is used as reference and is made to interfere with the rest of the wavefront. The contrast of two simultaneously measured interference-patterns provides a direct estimate of the wavefront phase, no additional computation being required. The proposed optical layout shows precise initial alignment to be the critical point in implementing the new wavefront-sensing scheme.

  8. Optical Slot-Waveguide Based Biochemical Sensors

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2009-06-01

    Full Text Available Slot-waveguides allow light to be guided and strongly confined inside a nanometer-scale region of low refractive index. Thus stronger light-analyte interaction can be obtained as compared to that achievable by a conventional waveguide, in which the propagating beam is confined to the high-refractive-index core of the waveguide. In addition, slot-waveguides can be fabricated by employing CMOS compatible materials and technology, enabling miniaturization, integration with electronic, photonic and fluidic components in a chip, and mass production. These advantages have made the use of slot-waveguides for highly sensitive biochemical optical integrated sensors an emerging field. In this paper, recent achievements in slot-waveguide based biochemical sensing will be reviewed. These include slot-waveguide ring resonator based refractometric label-free biosensors, label-based optical sensing, and nano-opto-mechanical sensors.

  9. Temperature Sensors Based on WGM Optical Resonators

    Science.gov (United States)

    Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute; Itchenko, Vladimir; Matsko, Andrey; Strekalov, Dmitry

    2008-01-01

    A proposed technique for measuring temperature would exploit differences between the temperature dependences of the frequencies of two different electromagnetic modes of a whispering gallery-mode (WGM) optical resonator. An apparatus based on this technique was originally intended to be part of a control system for stabilizing a laser frequency in the face of temperature fluctuations. When suitably calibrated, apparatuses based on this technique could also serve as precise temperature sensors for purposes other than stabilization of lasers. A sensor according to the proposal would include (1) a transparent WGM dielectric resonator having at least two different sets of modes characterized by different thermo-optical constants and (2) optoelectronic instrumentation for measuring the difference between the temperature-dependent shifts of the resonance frequencies of the two sets of modes.

  10. Computer Modeling for Optical Waveguide Sensors.

    Science.gov (United States)

    1987-12-15

    COSATI CODES 18 SUBJECT TERMS (Continue on reverse it necessary and cleritify by DIock numnerl FIEL GRUP SB-GOUP Optical waveguide sensors Computer...reflection. The resultant probe beam transmission may be plotted as a function of changes in the refractive index of the surrounding fluid medium. BASIC...all angles of incidence about the critical angle ecr. It should be noted that N in equation (3) is a function of e, since = sin - l sin 8 , see

  11. Fibre optic sensors for mine hazard detection

    Energy Technology Data Exchange (ETDEWEB)

    Liu, T; Wang, C; Wei, Y; Zhao, Y; Shang, Y; Wang, Z [Laser Institute of Shandong Academy of Science (China); Huo, D [Shandong Micro-Sensor Photonics Limited, 19 Keyuan Road, Jinan, Shandong province, 250014 (China); Ning, Y, E-mail: tongyuliu@hotmail.co [Intelligent Sensor Systems Limited, Rockley Manor, Rockley, Wiltshire (United Kingdom)

    2009-07-01

    We report the development of a comprehensive safety monitoring solution for coal mines. A number of fibre optic sensors have been developed and deployed for safety monitoring of mine roof integrity and hazardous gases. The FOS-based mine hazard detection system offers unique advantages of intrinsic safety, multi-location and multi-parameter monitoring. They can be potentially used to build expert systems for mine hazard early detection and prevention.

  12. Optical microfiber coil resonator refractometric sensor.

    Science.gov (United States)

    Xu, Fei; Horak, Peter; Brambilla, Gilberto

    2007-06-11

    We present a novel refractometric sensor based on a coated all-coupling optical-fiber-nanowire microcoil resonator which is robust, compact, and comprises an intrinsic fluidic channel. We calculate the device sensitivity and find its dependence on the nanowire diameter and coating thickness. A sensitivity as high as 700 nm/RIU and a refractive index resolution as low as 10(-10) are predicted.

  13. Fiber-optically sensorized composite wing

    Science.gov (United States)

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

    2014-04-01

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

  14. Optical Cutting Interruption Sensor for Fiber Lasers

    Directory of Open Access Journals (Sweden)

    Benedikt Adelmann

    2015-09-01

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

  15. Biomimetic optical sensor for aerospace applications

    Science.gov (United States)

    Frost, Susan A.; Gorospe, George E.; Wright, Cameron H. G.; Barrett, Steven F.

    2015-05-01

    We report on a fiber optic sensor based on the physiological aspects of the eye and vision-related neural layers of the common housefly (Musca domestica) that has been developed and built for aerospace applications. The intent of the research is to reproduce select features from the fly's vision system that are desirable in image processing, including high functionality in low-light and low-contrast environments, sensitivity to motion, compact size, lightweight, and low power and computation requirements. The fly uses a combination of overlapping photoreceptor responses that are well approximated by Gaussian distributions and neural superposition to detect image features, such as object motion, to a much higher degree than just the photoreceptor density would imply. The Gaussian overlap in the biomimetic sensor comes from the front-end optical design, and the neural superposition is accomplished by subsequently combining the signals using analog electronics. The fly eye sensor is being developed to perform real-time tracking of a target on a flexible aircraft wing experiencing bending and torsion loads during flight. We report on results of laboratory experiments using the fly eye sensor to sense a target moving across its field of view.

  16. A fiber-optic powered wireless sensor module made on elastomeric substrate for wearable sensors.

    Science.gov (United States)

    Lien, V; Lin, H; Chuang, J; Sailor, M; Lo, Y

    2004-01-01

    We demonstrate an integrated sensor module that combines a photonic nano-porous sensor and a bias-free optical powered RF transducer. The sensor signal is encoded in the RF frequency ready for transmission. The entire sensor module does not include battery and is constructed with the flexible and biocompatible elastomeric polymer, PDMS. This technology holds promise for wearable sensors.

  17. Study of fiber optic sugar sensor

    Indian Academy of Sciences (India)

    A Jayanth Kumar; N M Gowri; R Venkateswara Raju; G Nirmala; B S Bellubbi; T Radha Krishna

    2006-08-01

    Over the last two decades, the fiber optic technology has passed through many analytical stages. Some commercially available fiber optic sensors, though in a small way, are being used for automation in mechanical and industrial environments. They are also used for instrumentation and controls. In the present work, an intensity-modulated intrinsic fiber optic sugar sensor is presented. This type of sensor, with slight modification, can be used for on-line determination of the concentration of sugar content in sugarcane juice in sugar industry. In the present set-up, a plastic fiber made of polymethylmethacrylate is used. A portion of the cladding (1 cm, 2 cm, 3 cm) at the mid-point along the length of the fiber is removed. This portion is immersed in sugar solution of known concentration and refractive index. At one end of the fiber an 850 nm source is used and at the other end a power meter is connected. By varying the concentration of sugar solution, the output power is noted. These studies are made due to the change in refractive index of the fluid. The device was found to be very sensitive which is free from EMI and shock hazards, stable and repeatable and they can be remotely interfaced with a computer to give on-line measurements and thus become useful for application in sugar industries.

  18. Carbon-Nanotube-Based Chemical Gas Sensor

    Science.gov (United States)

    Kaul, Arunpama B.

    2010-01-01

    Conventional thermal conductivity gauges (e.g. Pirani gauges) lend themselves to applications such as leak detectors, or in gas chromatographs for identifying various gas species. However, these conventional gauges are physically large, operate at high power, and have a slow response time. A single-walled carbon-nanotube (SWNT)-based chemical sensing gauge relies on differences in thermal conductance of the respective gases surrounding the CNT as it is voltage-biased, as a means for chemical identification. Such a sensor provides benefits of significantly reduced size and compactness, fast response time, low-power operation, and inexpensive manufacturing since it can be batch-fabricated using Si integrated-circuit (IC) process technology.

  19. Solubility properties of siloxane polymers for chemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Grate, J.W. [Pacific Northwest Lab., Richland, WA (United States); Abraham, M.H. [University College, London (United Kingdom)

    1995-05-01

    This paper discusses the factors governing the sorption of vapors by organic polymers. The principles have been applied in the past for designing and selecting polymers for acoustic wave sensors; however they apply equally well to sorption of vapors by polymers used on optical chemical sensors. A set of solvation parameters (a table is presented for various organic vapors) have been developed that describe the particular solubility properties of individual solute molecules; they are used in linear solvation energy relationships (LSER) that model the sorption process. LSER coefficients are tabulated for five polysiloxanes; so are individual interaction terms for each of the 5 polymers. Dispersion interactions play a major role in determining overall partition coefficients; the log L{sup 16} (gas-liquid partition coefficient of solute on hexadecane) value of vapors are important in determining overall sorption. For the detection of basic vapors such as organophosphates, a hydrogen-bond acidic polymers will be most effective at sorbing them. Currently, fiber optic sensors are being developed where the cladding serves as a sorbent layer to collect and concentrate analyte vapors, which will be detected and identified spectroscopically. These solubility models will be used to design the polymers for the cladding for particular vapors.

  20. Optical sensors and their applications for probing biological systems

    DEFF Research Database (Denmark)

    Palanco, Marta Espina

    and mammalian cells. First, we performed Surface Enhanced Raman Spectroscopy (SERS) studies on intact plant materials via using silver plasmonic nanostructures. Our studies showed strong Raman signals which resemble to the presence of typical constituents such as carbohydrates, proteins and lipids of different......There is a great interest in exploring and developing new optical sensitive methodologies for probing complex biological systems. In this project we developed non-invasive and sensitive biosensor strategies for studying physiologically relevant chemical and physical properties of plant...... biological sample to provide a SERS-template where silver nanoparticles can grow, thus providing a new insight into SERS-based sensors for chemically sensing in-situ plant constituents. Optical manipulation techniques have been used to investigate mechanical properties of soft membrane cells, i.e. mammalian...

  1. Corrosion induced strain monitoring through fibre optic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Grattan, S K T [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Belfast, BT9 5AG (United Kingdom); Basheer, P A M [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Belfast, BT9 5AG (United Kingdom); Taylor, S E [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, David Keir Building, Belfast, BT9 5AG (United Kingdom); Zhao, W [School of Engineering and Mathematical Sciences, City University, Northampton Square, London, EC1V 0HB (United Kingdom); Sun, T [School of Engineering and Mathematical Sciences, City University, Northampton Square, London, EC1V 0HB (United Kingdom); Grattan, K T V [School of Engineering and Mathematical Sciences, City University, Northampton Square, London, EC1V 0HB (United Kingdom)

    2007-10-15

    The use of strain sensors is commonplace within civil engineering. Fibre optic strain sensors offer a number of advantages over the current electrical resistance type gauges. In this paper the use of fibre optic strain sensors and electrical resistance gauges to monitor the production of corrosion by-products has been investigated and reported.

  2. Optical stimulator for vision-based sensors

    DEFF Research Database (Denmark)

    Rössler, Dirk; Pedersen, David Arge Klevang; Benn, Mathias

    2014-01-01

    We have developed an optical stimulator system for vision-based sensors. The stimulator is an efficient tool for stimulating a camera during on-ground testing with scenes representative of spacecraft flights. Such scenes include starry sky, planetary objects, and other spacecraft. The optical...... precision and long-term stability. The system can be continuously used over several days. By facilitating a full camera including optics in the loop, the stimulator enables the more realistic simulation of flight maneuvers based on navigation cameras than pure computer simulations or camera stimulations...... stimulator is used as a test bench to simulate high-precision navigation by different types of camera systems that are used onboard spacecraft, planetary rovers, and for spacecraft rendezvous and proximity maneuvers. Careful hardware design and preoperational calibration of the stimulator result in high...

  3. Multiplexed detection of biological agents using optical microchip sensors

    Science.gov (United States)

    Bhatta, D.; McDonnell, M. B.; Perkins, E.

    2010-10-01

    A multi-channel optical microchip sensor system suitable for real-time, label-free detection of a wide range of biological agents is presented. SpectroSensTM chips containing multiple high-precision planar Bragg gratings are exploited as lowcost, robust refractive index sensors. Sensitivity to biological agents is conferred by functionalising individual sensing regions with different antibodies selected against numerous targets of interest. Antigen binding to the surfaceimmobilised antibodies results in localised changes in refractive index; upon laser-induced interrogation of the sensing region via optical fibres, these antibody-antigen interactions manifest as increases in wavelength of light reflected from the sensor chip. Real-time detection of multiple biological agents including bacterial cells/spores, viruses and toxins has been demonstrated. Further improvements to sensor performance including physical and chemical methods are also investigated. This multi-analyte capability highlights the potential use of this sensing technology in applications ranging from bio-hazard detection for defence purposes to point-of-care clinical diagnostics.

  4. Nanoscale chemical sensor based on organic thin-film transistors

    Science.gov (United States)

    Wang, Liang; Fine, Daniel; Dodabalapur, Ananth

    2004-12-01

    Nanoscale organic thin-film transistors were fabricated to investigate their chemical sensing properties. The use of a four-terminal geometry ensures that the sensor active area is truly nanoscale, and eliminates undesirable spreading currents. The sensor response was markedly different in nanoscale sensors compared to large-area sensors for the same analyte-semiconductor combination. The chemical sensing mechanisms in both microscale and nanoscale transistors are briefly discussed.

  5. Fiber optic sensors for military, industrial and commercial applications

    Science.gov (United States)

    James, K. A.; Quick, W. H.; Strahan, V. H.

    1978-01-01

    Four examples of specific fiber optic sensor system designs, each of which demonstrates a different optical modulation format, are described. The birefrigent temperature transducer illustrates direct digital signal modulation. The temperature/pressure dependent semiconductor filter illustrates high-pass optical wavelength signal encoding. The coupled polarized-mode transducer shows how a solid-state sensor can produce narrow-bandpass optical wavelength signal encoding. The luminescent temperature sensor illustrates a way to construct a solid state sensor in order to produce pulse width modulation of an optical signal.

  6. Fiber Optic Pressure Sensor using Multimode Interference

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-01

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

  7. Development of GaN-based micro chemical sensor nodes

    Science.gov (United States)

    Son, Kyung-ah; Prokopuk, Nicholas; George, Thomas; Moon, Jeong S.

    2005-01-01

    Sensors based on III-N technology are gaining significant interest due to their potential for monolithic integration of RF transceivers and light sources and the capability of high temperature operations. We are developing a GaN-based micro chemical sensor node for remote detection of chemical toxins, and present electrical responses of AlGaN/GaN HEMT (High Electron Mobility Transistor) sensors to chemical toxins as well as other common gases.

  8. Microcontrollers and optical sensors for education in optics and photonics

    Science.gov (United States)

    Dressler, Paul; Wielage, Heinz; Haiss, Ulrich; Vauderwange, Oliver; Wozniak, P.; Curticapean, Dan

    2014-09-01

    The digital revolution is going full steam ahead, with a constantly growing number of new devices providing a steady increase in complexity and power. Most of the success is based on one important invention: the microprocessor/microcontroller. In this paper the authors present how to integrate microcontrollers and optical sensors in the curricula of media engineering by combining subjects of media technology, optics, information technology and media design. Hereby the aim is not to teach these topics separate from each other, but to bring them together in interdisciplinary lectures, projects and applications. Microcontrollers can be applied in various ways to teach content from the fields of optics and photonics. They can be used to control LEDs, displays, light detectors and infrared sensors, which makes it possible to build measuring instruments like e.g. a lux meter, a light barrier or an optical distance meter. The learning goals are to stimulate the student's interest in the multiplicity of subjects related to this course and to support a deeper understanding of the close connections between them. The teaching method that the authors describe in their paper turned out to be very successful, as the participants are motivated to bring in their own ideas for projects, they spend more time than requested and as many students return to the courses as tutors. It is an example for effectual knowledge transfer and exchange of ideas among students.

  9. Progress of Mimetic Enzymes and Their Applications in Chemical Sensors.

    Science.gov (United States)

    Yang, Bin; Li, Jianping; Deng, Huan; Zhang, Lianming

    2016-11-01

    The need to develop innovative and reformative approaches to synthesize chemical sensors has increased in recent years because of demands for selectivity, stability, and reproducibility. Mimetic enzymes provide an efficient and convenient method for chemical sensors. This review summarizes the application of mimetic enzymes in chemical sensors. Mimetic enzymes can be classified into five categories: hydrolases, oxidoreductases, transferases, isomerases, and induced enzymes. Potential and recent applications of mimetic enzymes in chemical sensors are reviewed in detail, and the outlook of profound development has been illustrated.

  10. Human psychophysiological activity monitoring methods using fiber optic sensors

    Science.gov (United States)

    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.

  11. Development of a Robust Optical Glucose Sensor

    Science.gov (United States)

    Cote, Gerard Laurence

    1990-01-01

    The long term objective of this research was the development of a noninvasive, optically-based, polarimetric sensor to monitor in vivo glucose concentrations. The goal of diabetes therapy is to approximate the 24-hour blood glucose profile of a normal individual. There have been major advances in the development of reliable, versatile, and accurate pumps for the delivery of insulin to diabetic patients and in the development of control algorithms for closed-loop insulin delivery, however, there remain major obstacles to the development of clinically useful, continuous glucose sensors. The development of an accurate noninvasive glucose sensor would have significant application in the diagnosis and management of diabetes mellitis both in conjunction with, and independent of, the glucose pump controller applications. The linear polarization vector of light routes when it interacts with an optically active material such as glucose. The amount of rotation of polarization is directly proportional to the glucose concentration and to the path length. The ability to quantitate blood glucose levels for the limited available path length in our primary sensing site, namely, the anterior chamber of the eye, therefore depends on the signal-to-noise ratio of the polarization detector. Our primary research focused on the development and testing of a prototype optical polarimetry system using D + glucose solution in a test cell, as well as using an enucleated human eye to assess the sensitivity of the system to measure physiologic glucose levels for the approximate one centimeter path length present in the anterior chamber of the eye. Our research has led to the development of a true phase technique in which helium neon laser light was coupled through a rotating linear polarizer along with two stationary linear polarizers and two detectors to produce reference and signal outputs whose amplitudes varied sinusoidally and whose phase was proportional to the rotation of light caused by

  12. Micro Coriolis mass flow sensor for chemical micropropulsion systems

    NARCIS (Netherlands)

    Wiegerink, Remco J.; Lammerink, Theodorus S.J.; Groenesteijn, Jarno; Dijkstra, Pieter J.; Lötters, Joost Conrad

    2012-01-01

    We have designed a micromachined micro Coriolis flow sensor for the measurement of hydrazine (N2H4, High Purity Grade) propellant flow in micro chemical propulsion systems. The sensor measures mass flow up to 10 mg/s for a single thruster or up to 40 mg/s for four thrusters. The sensor will first be

  13. Fiber Optic Temperature Sensors for Thermal Protection Systems Project

    Data.gov (United States)

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

  14. A Fibre Optic Sensor Of Physiological Parameters

    Science.gov (United States)

    Legendre, J. P.; Forester, G. V.

    1986-11-01

    This paper presents an ultraminiature fibre optic probe capable of physiological monitoring in situ. The system has been described previously where a fibre optic reflectometer was configured as a temperature sensor and as a refractometer. For the present experiments a bare fibre tip was used as sensing element. We show that we have been able to monitor cyclic physiological parameters such as heart and respiratory rates in various animal preparations. The probe has been used to obtain signals from the oesophagus, the lower gastro-intestinal tract, the abdominal cavity and from blood vessels (arteries and veins). The probe has also measured phasic activity coincident with mechanical activity of isolated heart muscle. The small physical size of the sensor (125 µm diameter), its flexibility and the fact that it is biologically inert are all very important characteristics for medical and biological considerations. Most recently, the probe has been used to monitor cardiac and respiratory rates while obtaining NMR spectra assessing metabolic activity. This was possible only because the probe is magnetically transparent.

  15. Fiber optic pressure sensors for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-04-01

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

  16. Miniaturised Optical Fibre Sensor for Dew Detection Inside Organ Pipes

    Directory of Open Access Journals (Sweden)

    Francesco Baldini

    2008-01-01

    Full Text Available A new optical sensor for the continuous monitoring of the dew formation inside organ pipes was designed. This aspect is particularly critical for the conservation of organs in unheated churches since the dew formation or the condensation on the pipe surfaces can contribute to many kinds of physical and chemical disruptive mechanisms. The working principle is based on the change in the reflectivity which is observed on the surface of the fibre tip, when a water layer is formed on its distal end. Intensity changes of the order of 35% were measured, following the formation of the water layer on the distal end of a 400/430 μm optical fibre. Long-term tests carried out placing the fibre tip inside the base of an in-house-made metallic foot of an organ pipe located in an external environment revealed the consistency of the proposed system.

  17. Optical fiber sensor for low dose gamma irradiation monitoring

    Science.gov (United States)

    de Andrés, Ana I.; Esteban, Ã.`scar; Embid, Miguel

    2016-05-01

    An optical fiber gamma ray detector is presented in this work. It is based on a Terbium doped Gadolinium Oxysulfide (Gd2O2S:Tb) scintillating powder which cover a chemically etched polymer fiber tip. This etching improves the fluorescence gathering by the optical fiber. The final diameter has been selected to fulfill the trade-off between light gathering and mechanical strength. Powder has been encapsulated inside a microtube where the fiber tip is immersed. The sensor has been irradiated with different air Kerma doses up to 2 Gy/h with a 137Cs source, and the spectral distribution of the fluorescence intensity has been recorded in a commercial grade CCD spectrometer. The obtained signal-to-noise ratio is good enough even for low doses, which has allowed to reduce the integration time in the spectrometer. The presented results show the feasibility for using low cost equipment to detect/measure ionizing radiation as gamma rays are.

  18. Design Of Piezoelectric Microcantilever Chemical Sensors In COMSOL Multiphysics Area

    OpenAIRE

    Maziar Norouzi; Alireza Kashaninia

    2009-01-01

    This paper offers an analytical modeling ofthin-filmed, multi-layer piezoelectric microcantileversthat are used as MEMS sensors. These sensors arechemical kind and use piezoelectric microcantilever.These types of microcantilevers are covered withvariety of unique probe coating. The sensor has highsensitivity with external voltage measured in mV anduses PSD1 system to indentify chemical ingredients ofmaterials. The identification of the chemical ingredientof materials is based on change in ang...

  19. Magnetically remote-controlled optical sensor spheres for monitoring oxygen or pH.

    Science.gov (United States)

    Mistlberger, Günter; Koren, Klaus; Borisov, Sergey M; Klimant, Ingo

    2010-03-01

    Magnetic sensor macrospheres (MagSeMacs), i.e., stainless steel spheres coated with optical chemical sensors, are presented as an alternative to existing optical sensor patches and fiber-optical dip-probes. Such spheres can either be reversibly attached to the tip of an optical fiber (dip-probe) or trapped inside a vessel for read-out through the side wall. Moving the magnetic separator at the exterior enables measurements at varying positions with a single sensor. Moreover, the sensor's replacement is rapid and contactless. We measured dissolved oxygen or pH in stirred liquids, rotating flasks, and 24-well plates with a SensorDish-reader device for parallel cell culture monitoring. In these applications, MagSeMacs proved to be advantageous over conventional sensor patches and magnetic optical sensor particles because of their magnetism, spherical shape, reflectance, and size. These properties resulted in strong but reversible fixation, magnetic remote-controllability, short response times, high signal intensities, and simplified handling.

  20. Optical MEMS for chemical analysis and biomedicine

    CERN Document Server

    Jiang, Hongrui

    2016-01-01

    This book describes the current state of optical MEMS in chemical and biomedical analysis and brings together current trends and highlights topics representing the most exciting progress in recent years in the field.

  1. Fiber optic vibration sensor using bifurcated plastic optical fiber

    Science.gov (United States)

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

    2016-11-01

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

  2. Low-cost fiber optic weigh-in-motion sensor

    Science.gov (United States)

    Safaai-Jazi, A.; Ardekani, S. A.; Mehdikhani, M.

    1990-11-01

    A design for a fiber optic weigh in motion (WIM) sensor is proposed. A prototype of the proposed sensor is designed, manufactured, and tested in the laboratory for different load frequency combinations using a material testing system (MTS) machine. Statistical analysis of data are performed to assess the response of the sensor under varying load frequencies for comparison.

  3. Wave front sensor based on holographic optical elements

    Science.gov (United States)

    Kovalev, M. S.; Krasin, G. K.; Malinina, P. I.; Odinokov, S. B.; Sagatelyan, H. R.

    2016-08-01

    A wavefront sensor (WFS) based on holographic optical elements, namely computer generated Fourier holograms is proposed as a perspective alternative to the Shack-Hartmann sensor. A possibility of single and multimode sensor and the dependence of their characteristics were investigated.

  4. Analytical analysis of sensitivity of optical waveguide sensor

    African Journals Online (AJOL)

    user

    International Journal of Engineering, Science and Technology. Vol. ... optical sensors have attracted considerable attention, especially in the application of biochemical species ... Section 2 provides the principle and basic theory of optical sensors and the modal ... The electric and magnetic fields of a mode can be written as.

  5. Fiber-optic interferometric acoustic sensors for wind tunnel applications

    Science.gov (United States)

    Cho, Y. C.

    1993-01-01

    Progress in developing fiber-optic interferometric sensors for aeroacoustic measurements in wind tunnels, performed under the NASA program, is reported. Preliminary results show that the fiber-optic interferometer sensor array is a powerful instrument for solving complex acoustic measurement problems in wind tunnels, which cannot be resolved with the conventional transducer technique.

  6. Fiber-optic interferometric acoustic sensors for wind tunnel applications

    Science.gov (United States)

    Cho, Y. C.

    1993-01-01

    Progress in developing fiber-optic interferometric sensors for aeroacoustic measurements in wind tunnels, performed under the NASA program, is reported. Preliminary results show that the fiber-optic interferometer sensor array is a powerful instrument for solving complex acoustic measurement problems in wind tunnels, which cannot be resolved with the conventional transducer technique.

  7. Initial research of dual wavelength fibre optic perimeter sensor

    Science.gov (United States)

    Zyczkowski, M.; Kondrat, M.; Ciurapinski, W.

    2005-10-01

    The dual wavelength fibre optic perimeter sensor bases on input signals measurements in an arrangement of fibre optic Michelson and Sagnac interferometers with a 3 × 3 coupler and two semiconductor lasers. For 3 km long sensor we obtained 20-50m resolution of determination of disturbance point.

  8. Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology

    Science.gov (United States)

    Chullen, Cinda

    2015-01-01

    Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology" project will investigate newly developed optic gas sensors delivered from a Small Business Innovative Research (SBIR) Phase II effort. A ventilation test rig will be designed and fabricated to test the sensors while integrated with a Suited Manikin Test Apparatus (SMTA). Once the sensors are integrated, a series of test points will be completed to verify that the sensors can withstand Advanced Suit Portable Life Support System (PLSS) environments and associated human metabolic profiles for changes in pressure and levels of Oxygen (ppO2), carbon dioxide (ppCO2), and humidity (ppH2O).

  9. Implementation and characterization of a fibre-optic colour sensor

    Science.gov (United States)

    Bajić, Jovan S.; Stupar, Dragan Z.; Dakić, Bojan M.; Manojlović, Lazo M.; Slankamenac, Miloš P.; Živanov, Miloš B.

    2014-09-01

    In this paper the implementation of a fibre-optic sensor for colour detection based on reflective colour sensing is proposed. The sensor consists of three plastic optical fibres emitting red, green and blue components and one optical fibre collecting light reflected from the object. Red, green and blue LEDs are excited at different frequencies. In this way detection of the reflected signal is achieved with only one photodetector and three bandpass filters. Bandpass filters are implemented as digital IIR (infinite impulse response) filters on the microcontroller. Results obtained from the proposed sensor are compared with commercial available colour sensors and the results are satisfactory. Analyses of the sensor performance both in RGB and HSV colour space are done. The proposed solution shows that in specific applications by using the HSV model the sensor can be used both as a colour and distance sensor.

  10. SINGLE-CRYSTAL SAPPHIRE OPTICAL FIBER SENSOR INSTRUMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    A. Wang; G. Pickrell; R. May

    2002-09-10

    Accurate measurement of temperature is essential for the safe and efficient operation and control of a wide range of industrial processes. Appropriate techniques and instrumentation are needed depending on the temperature measurement requirements in different industrial processes and working environments. Harsh environments are common in many industrial applications. These harsh environments may involve extreme physical conditions, such as high-temperature, high-pressure, corrosive agents, toxicity, strong electromagnetic interference, and high-energy radiation exposure. Due to these severe environmental conditions, conventional temperature sensors are often difficult to apply. This situation has opened a new but challenging opportunity for the sensor society to provide robust, high-performance, and cost-effective temperature sensors capable of operating in those harsh environments. The focus of this research program has been to develop a temperature measurement system for temperature measurements in the primary and secondary stages of slagging gasifiers. For this application the temperature measurement system must be able to withstand the extremely harsh environment posed by the high temperatures and corrosive agents present in these systems. Real-time, accurate and reliable monitoring of temperature for the coal gasification process is important to realize the full economic potential of these gasification systems. Long life and stability of operation in the high temperature environment is essential for the temperature measurement system to ensure the continuous running of the coal gasification system over the long term. In this high temperature and chemically corrosive environment, rather limited high temperature measurement techniques such as high temperature thermocouples and optical/acoustic pyrometers are available, each with their own limitations. In this research program, five different temperature sensing schemes based on the single crystal sapphire

  11. Sensitivity of optical mass sensor enhanced by optomechanical coupling

    Energy Technology Data Exchange (ETDEWEB)

    He, Yong, E-mail: hey@cczu.edu.cn [School of Mathematics and Physics, Changzhou University, Changzhou 213164 (China)

    2015-03-23

    Optical mass sensors based on cavity optomechanics employ radiation pressure force to drive mechanical resonator whose mechanical susceptibility can be described by nonlinear optical transmission spectrum. In this paper, we present an optical mass sensor based on a two-cavity optomechanical system where the mechanical damping rate can be decreased by adjusting a pump power so that the mass sensitivity which depends on the mechanical quality factor has been enhanced greatly. Compared with that of an optical mass sensor based on single-cavity optomechanics, the mass sensitivity of the optical mass sensor is improved by three orders of magnitude. This is an approach to enhance the mass sensitivity by means of optomechanical coupling, which is suitable for all mass sensor based on cavity optomechanics. Finally, we illustrate the accurate measurement for the mass of a few chromosomes, which can be achieved based on the current experimental conditions.

  12. Evaluations of fiber optic sensors for interior applications

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-02-01

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

  13. Single mode variable-sensitivity fiber optic sensors

    Science.gov (United States)

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

    1992-01-01

    We review spatially-weighted optical fiber sensors that filter specific vibration modes from one dimensional beams placed in clamped-free and clamped-clamped configurations. The sensitivity of the sensor is varied along the length of the fiber by tapering circular-core, dual-mode optical fibers. Selective vibration mode suppression on the order of 10 dB was obtained. We describe experimental results and propose future extensions to single mode sensor applications.

  14. Improved Fiber-Optic-Coupled Pressure And Vibration Sensors

    Science.gov (United States)

    Zuckerwar, Allan J.; Cuomo, Frank W.

    1994-01-01

    Improved fiber-optic coupler enables use of single optical fiber to carry light to and from sensor head. Eliminates problem of alignment of multiple fibers in sensor head and simplifies calibration by making performance both more predictable and more stable. Sensitivities increased, sizes reduced. Provides increased margin for design of compact sensor heads not required to contain amplifier circuits and withstand high operating temperatures.

  15. EDITORIAL: Optical Fibre Sensors 18 (OFS-18)

    Science.gov (United States)

    Jones, Julian D. C.; Tatam, Ralph P.

    2007-10-01

    The International Conference on Optical Fibre Sensors (OFS-18) was held in October 2006 in Cancún, Mexico, under the general chairmanship of Dr Alexis Mendez (MCH Engineering LLC, USA) and Dr Fernando Mendoza (Centro de Investigaciones en Optica, Mexico). 'OFS', as it has become known, is firmly established as the leading international conference for the optical fibre sensor community. Since its inception, in London in 1983, and under the leadership of an international steering committee independent of any learned society or professional institution, it has been held approximately every eighteen months. The venue nominally rotates from Europe, to the Americas, and thence to Asia and the Pacific. OFS-18 demonstrated the continuing vigour of the community, with some 250 papers presented, plus two workshops, with attendance as international as ever. In recent years, it has become a tradition to publish a post-conference special issue in the journal Measurement Science and Technology, and these special issues offer a representative sample of the current status of the field. In the nearly 25 years since OFS began, many of the early ideas and laboratory-based proof-of-principle experiments have led to highly developed instrumentation systems, and to successful commercial products. Perhaps the most mature of all of these technologies is the optical fibre gyroscope, with the fibre hydrophone a close second—originally developed for defence applications for which it is now established, but with increasing relevance to the oil and gas industry; electromagnetic sensors based on the Faraday and electro-optic effects are of growing significance in the power generation and distribution industry; whilst in-fibre grating-based sensors occupy an expanding niche in structural monitoring, especially in civil engineering. It is therefore appropriate that the first day of OFS was devoted to workshops on structural health monitoring, and to commemorate the 30th anniversary of the

  16. A Passive Optical Fiber Current Sensor Based on YIG

    Institute of Scientific and Technical Information of China (English)

    Jing Shao; Wen Liu; Cui-Qing Liu; Duan Xu

    2008-01-01

    A research on passive optical fiber current sensor based on magneto-optical crystal and a new design of light path of the sensor head are presented. Both methods of dual-channel optical detection of the polarization state of the output light and signal processing are proposed. Signal processing can obtain the linear output of the current measurement of the wire more conveniently. Theoretical analysis on the magneto-optical fiber current sensor is given, followed by experiments. After that, further analysis is made according to the results, which leads to clarifying the exiting problems and their placements.

  17. Multi-resolution optical 3D sensor

    Science.gov (United States)

    Kühmstedt, Peter; Heinze, Matthias; Schmidt, Ingo; Breitbarth, Martin; Notni, Gunther

    2007-06-01

    A new multi resolution self calibrating optical 3D measurement system using fringe projection technique named "kolibri FLEX multi" will be presented. It can be utilised to acquire the all around shape of small to medium objects, simultaneously. The basic measurement principle is the phasogrammetric approach /1,2,3/ in combination with the method of virtual landmarks for the merging of the 3D single views. The system consists in minimum of two fringe projection sensors. The sensors are mounted on a rotation stage illuminating the object from different directions. The measurement fields of the sensors can be chosen different, here as an example 40mm and 180mm in diameter. In the measurement the object can be scanned at the same time with these two resolutions. Using the method of virtual landmarks both point clouds are calculated within the same world coordinate system resulting in a common 3D-point cloud. The final point cloud includes the overview of the object with low point density (wide field) and a region with high point density (focussed view) at the same time. The advantage of the new method is the possibility to measure with different resolutions at the same object region without any mechanical changes in the system or data post processing. Typical parameters of the system are: the measurement time is 2min for 12 images and the measurement accuracy is below 3μm up to 10 μm. The flexibility makes the measurement system useful for a wide range of applications such as quality control, rapid prototyping, design and CAD/CAM which will be shown in the paper.

  18. An optical reflected device using a molecularly imprinted polymer film sensor

    Energy Technology Data Exchange (ETDEWEB)

    Wu Nan; Feng Liang; Tan Yiyong [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Hu Jiming, E-mail: jmhu@whu.edu.cn [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2009-10-19

    A novel and highly selective optical sensor with molecularly imprinted polymer (MIP) film was fabricated and investigated. The optical sensor head employing a medium finesse molecularly imprinted polymer film has been fabricated and characterised. A blank polymer and formaldehyde imprinted polymer were using methacrylic acid as the functional monomer and the ethylene glycol dimethacrylate as a crosslinker. The transduction mechanism is discussed based on the changes of optical intensity of molecularly imprinted polymer film acting as an optical reflected sensor. Template molecules, which diffused into MIP, could cause film density, and refractive index change, and then induce measurable optical reflective intensity shifts. Based on the reflective intensity shifts, an optical reflection detection of formaldehyde was achieved by illuminating MIP with a laser beam. For the same MIP, the reflective intensity shift was proportional to the amount of template molecule. This optical sensor, based on an artificial recognition system, demonstrates long-time stability and resistance to harsh chemical environments. As the research moves forward gradually, we establish the possibilities of quantitative analysis primly, setting the groundwork to the synthesis of the molecular imprinted optical fiber sensor. The techniques show good reproducibility and sensitivity and will be of significant interest to the MIPcommunity.

  19. Operation principle of a novel curvature plastic fiber optic sensor

    Institute of Scientific and Technical Information of China (English)

    Fu Yili; Liu Renqiang; Wang Shuguo

    2005-01-01

    The operation principle of a new type of intensity modulate macrobend curvature optical fiber senor was presented based on surface light scattering theory. Sensor's static and dynamic performance was investigated. This type of sensor can distinguish between positive and negative bending directions. When curvature radius is larger than 50mm, the sensor will keep good linearity. Two-dimensional shape measurement experiments using curvature sensors have been implemented.

  20. Optics-less Sensors for Localization of Radiation Sources

    OpenAIRE

    Caulfield, H. J.; Yaroslavsky, L. P.; Goerzen, Ch.; Umansky, S.

    2008-01-01

    A new family of radiation sensors is introduced which do not require any optics. The sensors consist of arrays of elementary sub-sensors with natural cosine-law or similar angular sensitivity supplemented with a signal processing unit that computes optimal statistical estimations of source parameters. We show, both theoretically and by computer simulation, that such sensors are capable of accurate localization and intensity estimation of a given number of radiation sources and of imaging of a...

  1. Optical and Nonlinear Optical Response of Light Sensor Thin Films

    Directory of Open Access Journals (Sweden)

    S. Z. Weisz

    2005-04-01

    Full Text Available For potential ultrafast optical sensor application, both VO2 thin films andnanocomposite crystal-Si enriched SiO2 thin films grown on fused quartz substrates weresuccessfully prepared using pulsed laser deposition (PLD and RF co-sputteringtechniques. In photoluminescence (PL measurement c-Si/SiO2 film containsnanoparticles of crystal Si exhibits strong red emission with the band maximum rangingfrom 580 to 750 nm. With ultrashort pulsed laser excitation all films show extremelyintense and ultrafast nonlinear optical (NLO response. The recorded holography fromall these thin films in a degenerate-four-wave-mixing configuration shows extremelylarge third-order response. For VO2 thin films, an optically induced semiconductor-tometalphase transition (PT immediately occurred upon laser excitation. it accompanied.It turns out that the fast excited state dynamics was responsible to the induced PT. For c-Si/SiO2 film, its NLO response comes from the contribution of charge carriers created bylaser excitation in conduction band of the c-Si nanoparticles. It was verified byintroducing Eu3+ which is often used as a probe sensing the environment variations. Itturns out that the entire excited state dynamical process associated with the creation,movement and trapping of the charge carriers has a characteristic 500 ps duration.

  2. Evaluating Zeolite-Modified Sensors: towards a faster set of chemical sensors

    Science.gov (United States)

    Berna, A. Z.; Vergara, A.; Trincavelli, M.; Huerta, R.; Afonja, A.; Parkin, I. P.; Binions, R.; Trowell, S.

    2011-09-01

    The responses of zeolite-modified sensors, prepared by screen printing layers of chromium titanium oxide (CTO), were compared to unmodified tin oxide sensors using amplitude and transient responses. For transient responses we used a family of features, derived from the exponential moving average (EMA), to characterize chemo-resistive responses. All sensors were tested simultaneously against 20 individual volatile compounds from four chemical groups. The responses of the two types of sensors showed some independence. The zeolite-modified CTO sensors discriminated compounds better using either amplitude response or EMA features and CTO-modified sensors also responded three times faster.

  3. Optical sensor for rapid microbial detection

    Science.gov (United States)

    Al-Adhami, Mustafa; Tilahun, Dagmawi; Rao, Govind; Kostov, Yordan

    2016-05-01

    In biotechnology, the ability to instantly detect contaminants is key to running a reliable bioprocess. Bioprocesses are prone to be contaminated by cells that are abundant in our environment; detection and quantification of these cells would aid in the preservation of the bioprocess product. This paper discusses the design and development of a portable kinetics fluorometer which acts as a single-excitation, single-emission photometer that continuously measures fluorescence intensity of an indicator dye, and plots it. Resazurin is used as an indicator dye since the viable contaminant cells reduce Resazurin toResorufin, the latter being strongly fluorescent. A photodiode detects fluorescence change by generating current proportional to the intensity of the light that reached it, and a trans-impedance differential op-amp ensures amplification of the photodiodes' signal. A microfluidic chip was designed specifically for the device. It acts as a fully enclosed cuvette, which enhances the Resazurin reduction rate. E. coli in LB media, along with Resazurin were injected into the microfluidic chip. The optical sensor detected the presence of E. coli in the media based on the fluorescence change that occurred in the indicator dye in concentrations as low as 10 CFU/ml. A method was devised to detect and determine an approximate amount of contamination with this device. This paper discusses application of this method to detect and estimate sample contamination. This device provides fast, accurate, and inexpensive means to optically detect the presence of viable cells.

  4. Estimation of optical chemical shift in nuclear spin optical rotation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fang [Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Yao, Guo-hua [Key Laboratory of Ion Beam Bio-engineering, Institute of Technical Biology and Agriculture Engineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); He, Tian-jing [Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Chen, Dong-ming, E-mail: dmchen@ustc.edu.cn [Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Liu, Fan-chen, E-mail: fcliu@ustc.edu.cn [Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-05-19

    Highlights: • Analytical theory of nuclear spin optical rotation (NSOR) is further developed. • Derive formula of NSOR ratio R between different nuclei in a same molecule. • Calculated results of R agree with the experiments. • Analyze influence factors on R and chemical distinction by NSOR. - Abstract: A recently proposed optical chemical shift in nuclear spin optical rotation (NSOR) is studied by theoretical comparison of NSOR magnitude between chemically non-equivalent or different element nuclei in the same molecule. Theoretical expressions of the ratio R between their NSOR magnitudes are derived by using a known semi-empirical formula of NSOR. Taking methanol, tri-ethyl-phosphite and 2-methyl-benzothiazole as examples, the ratios R are calculated and the results approximately agree with the experiments. Based on those, the important influence factors on R and chemical distinction by NSOR are discussed.

  5. A fiber optic hybrid multifunctional AC voltage sensor

    Energy Technology Data Exchange (ETDEWEB)

    Sokolovsky, A.; Zadvornov, S. [IRE, Moscow (Russian Federation); Ryabko, M. [UFD, Moscow (Russian Federation)

    2008-07-01

    Hybrid sensors have the advantages of both electronic and optical technologies. Their sensing element is based on conventional transducers and the optical fiber is used as a transmission media for the optical signal encoded with information between the local module and the remote module. The power supply for the remote module is usually provided by a built-in photoelectric converter illuminated by the optical radiation going through the same or another optical fiber. Electro-optic hybrid sensors have been widely used because of the electrical isolation provided by optical fiber. In the conventional fiber optic voltage sensor, piezoelectric or electro-optic transducers are implemented. Processing and conditioning measurement information is a complex task in these sensors. Moreover, the considerable drawback of most of these systems is that only one parameter, usually voltage value, is measured. This paper presented a novel fiber optic hybrid sensor for alternating current voltage measurements. This instrument provides the simultaneous measurement of four parameters, notably voltage value, frequency, phase angle and the external temperature. The paper described the measurement technology of the instrument including the remote module and optical powering as well as the unique modulation algorithm. The results and conclusions were also presented. 7 refs., 4 figs.

  6. Embedded Optical Sensors for Thermal Barrier Coatings

    Energy Technology Data Exchange (ETDEWEB)

    David R. Clarke

    2005-11-09

    In the second year of this program on developing embedded optical sensors for thermal barrier coatings, our research has focused three topics: (1) Eu{sup 3+} doping for temperature sensing, (2) the effect of long-term, high-temperature aging on the characteristics of the luminescence from the Eu{sup 3+} ions of 8YSZ materials, (3) construction of a fiber-optic based luminescence detector system. It has been demonstrated that the variation in luminescence lifetime with temperature is identical for electron-beam evaporated Eu-doped YSZ coatings as for bulk ceramics of the same composition. Experiments indicate that the luminescence lifetime method of measuring temperatures is sensitive up to 1150 C for both Eu-doped YSZ coatings and Eu-doped Gd{sub 2}Zr{sub 2}O{sub 7}. Furthermore, the technique is sensitive up to 1250 C for the composition Eu{sub 2}Zr{sub 2}O{sub 7}. The luminescence spectra Eu-doped YSZ are insensitive to long-term aging at high-temperatures, even to 195 hours at 1425 C, except for a small frequency shift that is probably too small in measure except with instruments of the highest spectral resolution. The temperature of 1425 C is much higher than present engines attain or even planned in the foreseeable future. Nevertheless, experiments are on-going to explore longer term exposures. A fiber-optic based luminescence system has been constructed in which the hottest section of fiber operates to at least 1250 C.

  7. Ultra-High Temperature Sensors Based on Optical Property

    Energy Technology Data Exchange (ETDEWEB)

    Nabeel Riza

    2008-09-30

    In this program, Nuonics, Inc. has studied the fundamentals of a new Silicon Carbide (SiC) materials-based optical sensor technology suited for extreme environments of coal-fired engines in power production. The program explored how SiC could be used for sensing temperature, pressure, and potential gas species in a gas turbine environment. The program successfully demonstrated the optical designs, signal processing and experimental data for enabling both temperature and pressure sensing using SiC materials. The program via its sub-contractors also explored gas species sensing using SiC, in this case, no clear commercially deployable method was proven. Extensive temperature and pressure measurement data using the proposed SiC sensors was acquired to 1000 deg-C and 40 atms, respectively. Importantly, a first time packaged all-SiC probe design was successfully operated in a Siemens industrial turbine rig facility with the probe surviving the harsh chemical, pressure, and temperature environment during 28 days of test operations. The probe also survived a 1600 deg-C thermal shock test using an industrial flame.

  8. Ultra-High Temperature Sensors Based on Optical Property

    Energy Technology Data Exchange (ETDEWEB)

    Nabeel Riza

    2008-09-30

    In this program, Nuonics, Inc. has studied the fundamentals of a new Silicon Carbide (SiC) materials-based optical sensor technology suited for extreme environments of coal-fired engines in power production. The program explored how SiC could be used for sensing temperature, pressure, and potential gas species in a gas turbine environment. The program successfully demonstrated the optical designs, signal processing and experimental data for enabling both temperature and pressure sensing using SiC materials. The program via its sub-contractors also explored gas species sensing using SiC, in this case, no clear commercially deployable method was proven. Extensive temperature and pressure measurement data using the proposed SiC sensors was acquired to 1000 deg-C and 40 atms, respectively. Importantly, a first time packaged all-SiC probe design was successfully operated in a Siemens industrial turbine rig facility with the probe surviving the harsh chemical, pressure, and temperature environment during 28 days of test operations. The probe also survived a 1600 deg-C thermal shock test using an industrial flame.

  9. A Differential Reflective Intensity Optical Fiber Angular Displacement Sensor.

    Science.gov (United States)

    Jia, Binghui; He, Lei; Yan, Guodong; Feng, Yong

    2016-09-16

    In this paper, a novel differential reflective intensity optical fiber angular displacement sensor was proposed. This sensor can directly measure the angular and axial linear displacement of a flat surface. The structure of the sensor probe is simple and its basic principle was first analyzed according to the intensity modulation mechanisms. Secondly, in order to trim the dark output voltage to zero, the photoelectric conversion circuit was developed to adjust the signals. Then, the sensor model including the photoelectric conversion circuit has been established, and the influence of design parameters on the sensor output characteristic has been simulated. Finally, the design parameters of the sensor structure were obtained based on the simulation results; and an experimental test system was built for the sensor calibration. Experimental results show that the linear angular range and the sensitivity of the sensor were 74.4 and 0.051 V/°, respectively. Its change rules confirm the operating principle of the sensor well.

  10. A Differential Reflective Intensity Optical Fiber Angular Displacement Sensor

    Science.gov (United States)

    Jia, Binghui; He, Lei; Yan, Guodong; Feng, Yong

    2016-01-01

    In this paper, a novel differential reflective intensity optical fiber angular displacement sensor was proposed. This sensor can directly measure the angular and axial linear displacement of a flat surface. The structure of the sensor probe is simple and its basic principle was first analyzed according to the intensity modulation mechanisms. Secondly, in order to trim the dark output voltage to zero, the photoelectric conversion circuit was developed to adjust the signals. Then, the sensor model including the photoelectric conversion circuit has been established, and the influence of design parameters on the sensor output characteristic has been simulated. Finally, the design parameters of the sensor structure were obtained based on the simulation results; and an experimental test system was built for the sensor calibration. Experimental results show that the linear angular range and the sensitivity of the sensor were 74.4 and 0.051 V/°, respectively. Its change rules confirm the operating principle of the sensor well. PMID:27649199

  11. Networking of optical fiber sensors for extreme environments

    Science.gov (United States)

    Peters, Kara

    2016-04-01

    One of the major benefits of optical fiber sensors for applications to structural health monitoring and other structural measurements is their inherent multiplexing capabilities, meaning that a large number of sensing locations can be achieved with a single optical fiber. It has been well demonstrated that point wise sensors can be multiplexed to form sensor networks or optical fibers integrated with distributed sensing techniques. The spacing between sensing locations can also be tuned to match different length scales of interest. This article presents an overview of directions to adapt optical fiber sensor networking techniques into new applications where limitations such as available power or requirements for high data acquisition speeds are a driving factor. In particular, the trade-off between high fidelity sensor information vs. rapid signal processing or data acquisition is discussed.

  12. Optical Fiber Sensors Based on Nanoparticle-Embedded Coatings

    Directory of Open Access Journals (Sweden)

    Aitor Urrutia

    2015-01-01

    Full Text Available The use of nanoparticles (NPs in scientific applications has attracted the attention of many researchers in the last few years. The use of NPs can help researchers to tune the physical characteristics of the sensing coating (thickness, roughness, specific area, refractive index, etc. leading to enhanced sensors with response time or sensitivity better than traditional sensing coatings. Additionally, NPs also offer other special properties that depend on their nanometric size, and this is also a source of new sensing applications. This review focuses on the current status of research in the use of NPs within coatings in optical fiber sensing. Most used sensing principles in fiber optics are briefly described and classified into several groups: absorbance-based sensors, interferometric sensors, fluorescence-based sensors, fiber grating sensors, and resonance-based sensors, among others. For each sensor group, specific examples of the utilization of NP-embedded coatings in their sensing structure are reported.

  13. Optical voltage sensors: principle, problem and research proposal

    Science.gov (United States)

    Li, Changsheng

    2016-10-01

    Sensing principles and main problems to be solved for optical voltage sensors are briefly reviewed. Optical effects used for voltage sensing usually include electro-optic Pockels and Kerr effects, electro-gyration effect, elasto-optical effect, and electroluminescent effects, etc. In principle, typical optical voltage sensor is based on electro-optic Pockels crystals and closed-loop signal detection scheme. Main problems to be solved for optical voltage sensors include: how to remove influence of unwanted multiple optical effects on voltage sensing performance; how to select or develop a proper voltage sensing material and element; how to keep optical phase bias to be stable under temperature fluctuation and vibration; how to achieve dc voltage sensing, etc. In order to suppress the influence of unwanted optical effects and light beam coupling-related loss on voltage sensing signals, we may pay more attention to all-fiber and waveguide voltage sensors. Voltage sensors based on electroluminescent effects are also promising in some application fields due to their compact configuration, low cost and potential long-term reliability.

  14. Nanotechnologv Enabled Biological and Chemical Sensors

    Science.gov (United States)

    Koehne, Jessica; Meyyappan, M.

    2011-01-01

    Nanotechnology is an enabling technology that will impact almost all economic sectors: one of the most important and with great potential is the health/medical sector. - Nanomaterials for drug delivery - Early warning sensors - Implantable devices - Artificial parts with improved characteristics Carbon nanotubes and nanofibers show promise for use in sensor development, electrodes and other biomedical applications.

  15. Hydrogel/fiber optic sensor for distributed measurement of humidity and pH value

    Science.gov (United States)

    MacLean, Alistair; Michie, W. Craig; Pierce, S. Gareth; Thursby, Graham; Culshaw, Brian; Moran, Chris; Graham, Neil B.

    1998-07-01

    The combination of chemically sensitive, swellable polymer materials with novel optical fiber cable designs to transduce the swelling activity into microbend loss enables a simple yet powerful sensor to be produced. Interrogating such cables with standard optical time domain reflectoctrometry (OTDR) instruments allows particular chemicals of interest to be detected and located along a cable which may extend to several kilometers. We report here on a sensor cable which uses a water swellable material, a hydrogel, to detect positions of water ingress, relative humidity level or pH value. In direct water ingress tests, wet sensor lengths as small as 5 cm in several hundreds of meters have been detected using conventional OTDRs. Following a review of the sensor design, we present the results of an investigation of the mechanical interaction between the hydrogel polymer and the optical fiber within the sensor. The behavior of the sensor is then characterized within environments of different relative humidity levels from 70 percent to 100 percent at temperatures ranging from 0 to 60 degrees C. The sensor was initially designed for applications within civil engineering but can be applied to a much broader range of measurement requirements, for example soil moisture measurement. We will report details on experimental observations on concrete cure within reinforcing tendon ducts and soil humidity measurements within different soil types.

  16. Optimize Etching Based Single Mode Fiber Optic Temperature Sensor

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2014-02-01

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

  17. Non-specific sensor arrays for chemical detection

    Science.gov (United States)

    Johnson, Kevin; Minor, Christian

    2015-05-01

    Non-specific chemical sensor arrays have been the subject of considerable research efforts over the past thirty years with the idea that, by analogy to vertebrate olfaction, they are potentially capable of rendering complex chemical assessments with relatively modest logistical footprints. However, the actual implementation of such devices in challenging "real world" scenarios has arguably continued to fall short of these expectations. This work examines the inherent limitations of such devices for complex chemical sensing scenarios, placing them on a continuum between simple univariate sensors and complex multivariate analytical instrumentation and analyzing their utility in general-purpose chemical detection and accurate chemical sensing in the presence of unknown "unknowns." Results with simulated and acquired data sets are presented with discussion of the implications in development of chemical sensor arrays suitable for complex scenarios.

  18. CCD polarization imaging sensor with aluminum nanowire optical filters.

    Science.gov (United States)

    Gruev, Viktor; Perkins, Rob; York, Timothy

    2010-08-30

    We report an imaging sensor capable of recording the optical properties of partially polarized light by monolithically integrating aluminum nanowire optical filters with a CCD imaging array. The imaging sensor, composed of 1000 by 1000 imaging elements with 7.4 μm pixel pitch, is covered with an array of pixel-pitch matched nanowire optical filters with four different orientations offset by 45°. The polarization imaging sensor has a signal-to-noise ratio of 45 dB and captures intensity, angle and degree of linear polarization in the visible spectrum at 40 frames per second with 300 mW of power consumption.

  19. Zirconia-based solid state chemical gas sensors

    CERN Document Server

    Zhuiykov, S

    2000-01-01

    This paper presents an overview of chemical gas sensors, based on solid state technology, that are sensitive to environmental gases, such as O sub 2 , SO sub x , NO sub x , CO sub 2 and hydrocarbons. The paper is focussed on performance of electrochemical gas sensors that are based on zirconia as a solid electrolyte. The paper considers sensor structures and selection of electrode materials. Impact of interfaces on sensor performance is discussed. This paper also provides a brief overview of electrochemical properties of zirconia and their effect on sensor performance. Impact of auxiliary materials on sensors performance characteristics, such as sensitivity, selectivity, response time and recovery time, is also discussed. Dual gas sensors that can be applied for simultaneous monitoring of the concentration of both oxygen and other gas phase components, are briefly considered

  20. Plasmonics Based Harsh Environment Compatible Chemical Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Michael Carpenter

    2012-01-15

    Au-YSZ, Au-TiO{sub 2} and Au-CeO{sub 2} nanocomposite films have been investigated as a potential sensing element for high-temperature plasmonic sensing of H{sub 2}, CO, and NO{sub 2} in an oxygen containing environment. The Au-YSZ and Au-TiO{sub 2} films were deposited using PVD methods, while the CeO{sub 2} thin film was deposited by molecular beam epitaxy (MBE) and Au was implanted into the as-grown film at an elevated temperature followed by high temperature annealing to form well-defined Au nanoclusters. Each of the films were characterized by x-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). For the gas sensing experiments, separate exposures to varying concentrations of H{sub 2}, CO, and NO{sub 2} were performed at a temperature of 500°C in oxygen backgrounds of 5.0, 10, and ~21% O{sub 2}. Changes in the localized surface plasmon resonance (LSPR) absorption peak were monitored during gas exposures and are believed to be the result of oxidation-reduction processes that fill or create oxygen vacancies in the respective metal oxides. This process affects the LSPR peak position either by charge exchange with the Au nanoparticles or by changes in the dielectric constant surrounding the particles. Hyperspectral multivariate analysis was used to gauge the inherent selectivity of the film between the separate analytes. From principal component analysis (PCA), unique and identifiable responses were seen for each of the analytes. Linear discriminant analysis (LDA) was also used on the Au-CeO{sub 2} results and showed separation between analytes as well as trends in gas concentration. Results indicate that each of the films are is selective towards O{sub 2}, H{sub 2}, CO, and NO{sub 2} in separate exposures. However, when the films were analyzed in a sensor array based experiment, ie simultaneous exposures to the target gases, PCA analysis of the combined response showed an even greater selective character towards the target gases. Combined

  1. Integrated optical sensors utilizing slow-light propagation in grated-waveguide cavities

    NARCIS (Netherlands)

    Pham, Van So

    2012-01-01

    Owing to the small size of integrated optical (IO) devices many basic functions can be integrated on one single IO chip. IO sensors are suitable candidates for accurate detection of small changes of physical or chemical parameters. The integration offers advantages such as enabling a high density of

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

    Directory of Open Access Journals (Sweden)

    Dr. Bushra. R. Mhdi

    2013-07-01

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

  3. Biomimetic chemical sensors using bioengineered olfactory and taste cells

    Science.gov (United States)

    Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

    2014-01-01

    Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well. PMID:25482234

  4. Development of Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

    Science.gov (United States)

    Hunter, G. W.; Neudeck, P. G.; Fralick, G.; Thomas, V.; Liu, C. C.; Wu, W. H.; Ward, B.; Makel, D.

    2002-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, fire detection, and environmental monitoring. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. However, due to issues of selectivity and cross-sensitivity, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. This paper discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, hydrazine, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  5. Simple fiber optic sensor for applications in security systems

    Science.gov (United States)

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

    2014-10-01

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

  6. Experimental results of fiber optic contrast-sensitive dislocation sensor

    Science.gov (United States)

    Zyczkowski, M.; Szustakowski, M.; Palka, N.

    2005-05-01

    The dislocation sensor based on the contrast phenomenon in an unbalanced fiber optic Michelson interferometer with a 3 x 3 coupler and a semiconductor multimode laser. Periodic contrast oscillations, which depend on a laser spectrum, occur if a measuring arm of the interferometer is elongated. A conception of the elongation sensor that based on linearization of contrast oscillations is shown. Next, a setup of the sensor and signal processing scheme of the sensor is presented. During measurements, for 1-m long sensor we obtained 5-mm measuring range with +/-28-μm uncertainty. Explanation of these differences and conclusion to further research are formulated.

  7. The research of optical windows used in aircraft sensor systems

    Institute of Scientific and Technical Information of China (English)

    Zhou Feng; Li Yan; Tang Tian-Jin

    2012-01-01

    The optical windows used in aircrafts protect their imaging sensors from environmental effects.Considering the imaging performance,flat surfaces are traditionally used in the design of optical windows.For aircrafts operating at high speeds,the optical windows should be relatively aerodynamic,but a flat optical window may introduce unacceptably high drag to the airframes.The linear scanning infrared sensors used in aircrafts with,respectively,a fiat window,a spherical window and a toric window in front of the aircraft sensors are designed and compared.Simulation results show that the optical design using a toric surface has the integrated advantages of field of regard,aerodynamic drag,narcissus effect,and imaging performance,so the optical window with a toric surface is demonstrated to be suited for this application.

  8. Fiber Optic Strain Sensor for Planetary Gear Diagnostics

    Science.gov (United States)

    Kiddy, Jason S.; Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason

    2011-01-01

    This paper presents a new sensing approach for helicopter damage detection in the planetary stage of a helicopter transmission based on a fiber optic strain sensor array. Complete helicopter transmission damage detection has proven itself a difficult task due to the complex geometry of the planetary reduction stage. The crowded and complex nature of the gearbox interior does not allow for attachment of sensors within the rotating frame. Hence, traditional vibration-based diagnostics are instead based on measurements from externally mounted sensors, typically accelerometers, fixed to the gearbox exterior. However, this type of sensor is susceptible to a number of external disturbances that can corrupt the data, leading to false positives or missed detection of potentially catastrophic faults. Fiber optic strain sensors represent an appealing alternative to the accelerometer. Their small size and multiplexibility allows for potentially greater sensing resolution and accuracy, as well as redundancy, when employed as an array of sensors. The work presented in this paper is focused on the detection of gear damage in the planetary stage of a helicopter transmission using a fiber optic strain sensor band. The sensor band includes an array of 13 strain sensors, and is mounted on the ring gear of a Bell Helicopter OH-58C transmission. Data collected from the sensor array is compared to accelerometer data, and the damage detection results are presented

  9. Piezoresistive Chemical Sensors Based on Functionalized Hydrogels

    Directory of Open Access Journals (Sweden)

    Margarita Guenther

    2014-06-01

    Full Text Available Thin films of analyte-specific hydrogels were combined with microfabricated piezoresistive pressure transducers to obtain chemomechanical sensors that can serve as selective biochemical sensors for a continuous monitoring of metabolites. The gel swelling pressure has been monitored in simulated physiological solutions by means of the output signal of piezoresistive sensors. The interference by fructose, human serum albumin, pH, and ionic concentration on glucose sensing was studied. With the help of a database containing the calibration curves of the hydrogel-based sensors at different values of pH and ionic strength, the corrected values of pH and glucose concentration were determined using a novel calibration algorithm.

  10. Physical and chemical sensing using monolithic semiconductor optical transducers

    Science.gov (United States)

    Zappe, Hans P.; Hofstetter, Daniel; Maisenhoelder, Bernd; Moser, Michael; Riel, Peter; Kunz, Rino E.

    1997-09-01

    We present two monolithically integrated optical sensor systems based on semiconductor photonic integrated circuits. These compact, robust and highly functional transducers perform all necessary optical and electro-optical functions on-chip; extension to multi-sensor arrays is easily envisaged. A monolithic Michelson interferometer for high-resolution displacement measurement and a monolithic Mach-Zehnder interferometer for refractometry are discussed.

  11. Broadband ultrasonic sensor array via optical frequency domain reflectometry

    Science.gov (United States)

    Gabai, Haniel; Steinberg, Idan; Eyal, Avishay

    2015-03-01

    We introduce a new approach for multiplexing fiber-based ultrasound sensors using Optical Frequency Domain Reflectometry (OFDR). In the present demonstration of the method, each sensor was a short section of Polyimide-coated single-mode fiber. One end of the sensing fiber was pigtailed to a mirror and the other end was connected, via a fiber optic delay line, to a 1X4 fiber coupler. The multiplexing was enabled by using a different delay to each sensor. Ultrasonic excitation was performed by a 1MHz transducer which transmitted 4μs tone-bursts above the sensor array. The ultrasound waves generated optical phase variations in the fibers which were detected using the OFDR method. The ultrasound field at the sensors was successfully reconstructed without any noticeable cross-talk.

  12. Optical Fiber Grating Sensor for Force Measurement of Anchor Cable

    Institute of Scientific and Technical Information of China (English)

    JIANG Desheng; FU Jinghua; LIU Shengchun; SUI Lingfeng; FU Rong

    2006-01-01

    The development of the sensor suitable for measuring large load stress to the anchor cable becomes an important task in bridge construction and maintenance. Therefore, a new type of optical fiber sensor was developed in the laboratory - optical fiber grating sensor for force measurement of anchor cable (OFBFMAC). No similar report about this kind of sensor has been found up to now in China and other countries. This sensor is proved to be an effective way of monitoring in processes of anchor cable installation, cable cutting, cable force regulation, etc, with the accurate and repeatable measuring results. Its successful application in the tie bar cable force safety monitoring for Wuhan Qingchuan bridge is a new exploration of optical fiber grating sensing technology in bridge tie bar monitoring system.

  13. Optical fiber cable chemical stripping fixture

    Science.gov (United States)

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

    1995-01-01

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

  14. Bragg grating chemical sensor with hydrogel as sensitive element

    Institute of Scientific and Technical Information of China (English)

    Xiaomei Liu(刘小梅); Shilie Zheng(郑史烈); Xianmin Zhang(章献民); Jun Cong(丛军); Kangsheng Chen(陈抗生); Jian Xu(徐坚)

    2004-01-01

    A novel fiber Bragg grating (FBG) based chemical sensor using hydrogel, a swellable polymer, as sensitive element is demonstrated. The sensing mechanism relies on the shift of Bragg wavelength due to the stress resulted from volume change of sensitive swellable hydrogel responding to the change of external environment. A polyacrylamide hydrogel fiber grating chemical sensor is made, and the experiments on its sensitivity to the salinity are performed. The sensitivity is low due to the less stress from the shrinking or swelling of hydrogels. Reducing the cross diameter of the grating through etching with hydrofluoric acid can greatly improve the sensitivity of the sensor.

  15. Highly sensitive fiber grating chemical sensors: An effective alternative to atomic absorption spectroscopy

    Science.gov (United States)

    Laxmeshwar, Lata. S.; Jadhav, Mangesh S.; Akki, Jyoti. F.; Raikar, Prasad; Kumar, Jitendra; prakash, Om; Raikar, U. S.

    2017-06-01

    Accuracy in quantitative determination of trace elements like Zinc, present in drinking water in ppm level, is a big challenge and optical fiber gratings as chemical sensors may provide a promising solution to overcome the same. This paper presents design of two simple chemical sensors based on the principle of shift in characteristic wavelength of gratings with change in their effective refractive index, to measure the concentration of Zinc in drinking water using etched short period grating (FBG) and Long period grating (LPG) respectively. Three samples of drinking water from different places have been examined for presence of Zinc. Further, the results obtained by our sensors have also been verified with the results obtained by a standard method, Atomic absorption spectroscopy (AAS). The whole experiment has been performed by fixing the fibers in a horizontal position with the sensor regions at the center of the fibers, making it less prone to disturbance and breaking. The sensitivity of LPG sensor is about 205 times that of the FBG sensor. A few advantages of Fiber grating sensors, besides their regular features, over AAS have also been discussed, that make our sensors potential alternatives for existing techniques in determination of trace elements in drinking water.

  16. Optical fiber strain sensor with improved linearity range

    Science.gov (United States)

    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.

  17. Optical arc sensor using energy harvesting power source

    Science.gov (United States)

    Choi, Kyoo Nam; Rho, Hee Hyuk

    2016-06-01

    Wireless sensors without external power supply gained considerable attention due to convenience both in installation and operation. Optical arc detecting sensor equipping with self sustaining power supply using energy harvesting method was investigated. Continuous energy harvesting method was attempted using thermoelectric generator to supply standby power in micro ampere scale and operating power in mA scale. Peltier module with heat-sink was used for high efficiency electricity generator. Optical arc detecting sensor with hybrid filter showed insensitivity to fluorescent and incandescent lamps under simulated distribution panel condition. Signal processing using integrating function showed selective arc discharge detection capability to different arc energy levels, with a resolution below 17J energy difference, unaffected by bursting arc waveform. The sensor showed possibility for application to arc discharge detecting sensor in power distribution panel. Also experiment with proposed continuous energy harvesting method using thermoelectric power showed possibility as a self sustainable power source of remote sensor.

  18. Integrated optical waveguide sensor for lighting impulse electric field measurement

    Science.gov (United States)

    Zhang, Jiahong; Chen, Fushen; Sun, Bao; Chen, Kaixin

    2014-09-01

    A Lithium niobate (LiNbO3) based integrated optical E-field sensor with an optical waveguide Mach-Zehnder interferometer (MZI) and a tapered antenna has been designed and fabricated for the measurement of the pulsed electric field. The minimum detectable E-field of the sensor was 10 kV/m. The sensor showed a good linear characteristic while the input E-fields varied from 10 kV/m to 370 kV/m. Furthermore, the maximum detectable E-field of the sensor, which could be calculated from the sensor input/output characteristic, was approximately equal to 1000 kV/m. All these results suggest that such sensor can be used for the measurement of the lighting impulse electric field.

  19. Optical fiber based slide tactile sensor for underwater robots

    Institute of Scientific and Technical Information of China (English)

    TAN Ding-zhong; WANG Qi-ming; SONG Rui-han; YAO Xin; GU Yi-hua

    2008-01-01

    In the underwater environment,many visual sensors don't work,and many sensors which work well for robots working in space or on land can not be used underwater.Therefore,an optical fiber slide tactile sensor was designed based on the inner modulation mechanism of optical fibers.The principles and structure of the sensor are explained in detail.Its static and dynamic characteristics were analyzed theoretically and then simulated.A dynamic characteristic model was built and the simulation made using the GA based neural network.In order to improve sensor response,the recognition model of the sensor was designed based on the'inverse solution'principle of neural networks,increasing the control precision and the sensitivity of the manipulator.

  20. Optical arc sensor using energy harvesting power source

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyoo Nam, E-mail: knchoi@inu.ac.kr; Rho, Hee Hyuk, E-mail: rdoubleh0902@inu.ac.kr [Dept. of Information and Telecommunication Engineering Incheon National University Incheon 22012 (Korea, Republic of)

    2016-06-03

    Wireless sensors without external power supply gained considerable attention due to convenience both in installation and operation. Optical arc detecting sensor equipping with self sustaining power supply using energy harvesting method was investigated. Continuous energy harvesting method was attempted using thermoelectric generator to supply standby power in micro ampere scale and operating power in mA scale. Peltier module with heat-sink was used for high efficiency electricity generator. Optical arc detecting sensor with hybrid filter showed insensitivity to fluorescent and incandescent lamps under simulated distribution panel condition. Signal processing using integrating function showed selective arc discharge detection capability to different arc energy levels, with a resolution below 17 J energy difference, unaffected by bursting arc waveform. The sensor showed possibility for application to arc discharge detecting sensor in power distribution panel. Also experiment with proposed continuous energy harvesting method using thermoelectric power showed possibility as a self sustainable power source of remote sensor.

  1. High Performance Fiber-Optic Sensor for Environmental Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research (LGR) proposes to develop a low-cost, compact, lightweight, rugged and easy-to-use environmental monitoring optical fiber sensor device based on...

  2. In-Space Distributed Fiber Optic Hydrogen Leak Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Broadband Photonics Inc. proposes development of a patent-pending distributed fiber optic sensor for in-space hydrogen leak detection. Reliable and fast detection of...

  3. Fiber Optic Continuous Liquid Sensor for Cryogenic Propellant Gauging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Broadband Photonics Incorporated proposes to develop a patent-pending fiber optic continuous liquid sensor for low-thrust level settled mass gauging with measurement...

  4. Compact All Solid State Oceanic Inherent Optical Property Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This work concerns the development of a prototype of a Volume Scattering Function (VSF) sensor for measurement of this inherent optical property(IOP) of seawater....

  5. An embedded optical nanowire loop resonator refractometric sensor.

    Science.gov (United States)

    Xu, Fei; Pruneri, Valerio; Finazzi, Vittoria; Brambilla, Gilberto

    2008-01-21

    A novel refractometric sensor based on an embedded optical nanowire loop resonator is presented. The device sensitivity has been studied in two typical configurations and its dependence on the nanowire diameter and coating thickness determined.

  6. Characterization of optical strain sensors based on silicon waveguides

    NARCIS (Netherlands)

    Westerveld, W.J.; Pozo Torres, J.M.; Muilwijk, P.M.; Leinders, S.M.; Harmsma, P.J.; Tabak, E.; Dool, T.C. van den; Dongen, K.W.A. van; Yousefi, M.; Urbach, H.P.

    2013-01-01

    Strain gauges are widely employed in microelectromechanical systems (MEMS) for sensing of, for example, deformation, acceleration, pressure, or sound [1]. Such gauges are typically based on electronic piezoresistivity. We propose integrated optical sensors which have particular benefits: insensitivi

  7. An Optical Fiber Displacement Sensor Using RF Interrogation Technique.

    Science.gov (United States)

    Kim, Hyeon-Ho; Choi, Sang-Jin; Jeon, Keum Soo; Pan, Jae-Kyung

    2016-02-24

    We propose a novel non-contact optical fiber displacement sensor. It uses a radio frequency (RF) interrogation technique which is based on bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). The displacement is measured from the free spectral range (FSR) which is determined by the dip frequencies of the modulated MZ-EOM transfer function. In experiments, the proposed sensor showed a sensitivity of 456 kHz/mm or 1.043 kHz/V in a measurement range of 7 mm. The displacement resolution of the proposed sensor depends on the linewidth and the power of the optical source. Resolution better than 0.05 μm would be achieved if an optical source which has a linewidth narrower than 1.5 nm and a received power larger than -36 dBm is used. Also, the multiplexing characteristic of the proposed sensor was experimentally validated.

  8. In-Space Distributed Fiber Optic Hydrogen Leak Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Broadband Photonics Inc. proposes development of a patent-pending distributed fiber optic sensor for in-space hydrogen leak detection. Reliable and fast detection of...

  9. Optical hydrogen sensors based on metal-hydrides

    Science.gov (United States)

    Slaman, M.; Westerwaal, R.; Schreuders, H.; Dam, B.

    2012-06-01

    For many hydrogen related applications it is preferred to use optical hydrogen sensors above electrical systems. Optical sensors reduce the risk of ignition by spark formation and are less sensitive to electrical interference. Currently palladium and palladium alloys are used for most hydrogen sensors since they are well known for their hydrogen dissociation and absorption properties at relatively low temperatures. The disadvantages of palladium in sensors are the low optical response upon hydrogen loading, the cross sensitivity for oxygen and carbon, the limited detection range and the formation of micro-cracks after some hydrogen absorption/desorption cycles. In contrast to Pd, we find that the use of magnesium or rear earth bases metal-hydrides in optical hydrogen sensors allow tuning of the detection levels over a broad pressure range, while maintaining a high optical response. We demonstrate a stable detection layer for detecting hydrogen below 10% of the lower explosion limit in an oxygen rich environment. This detection layer is deposited at the bare end of a glass fiber as a micro-mirror and is covered with a thin layer of palladium. The palladium layer promotes the hydrogen uptake at room temperature and acts as a hydrogen selective membrane. To protect the sensor for a long time in air a final layer of a hydrophobic fluorine based coating is applied. Such a sensor can be used for example as safety detector in automotive applications. We find that this type of fiber optic hydrogen sensor is also suitable for hydrogen detection in liquids. As example we demonstrate a sensor for detecting a broad range of concentrations in transformer oil. Such a sensor can signal a warning when sparks inside a high voltage power transformer decompose the transformer oil over a long period.

  10. Forty-Four Pass Fibre Optic Loop for Improving the Sensitivity of Surface Plasmon Resonance Sensors

    CERN Document Server

    Su, Chin B

    2007-01-01

    A forty-four pass fibre optic surface plasmon resonance sensor that enhances detection sensitivity according to the number of passes is demonstrated for the first time. The technique employs a fibre optic recirculation loop that passes the detection spot forty- four times, thus enhancing sensitivity by a factor of forty-four. Presently, the total number of passes is limited by the onset of lasing action of the recirculation loop. This technique offers a significant sensitivity improvement for various types of plasmon resonance sensors that may be used in chemical and biomolecule detections.

  11. Selected area chemical vapor deposition of thin films for conductometric microelectronic chemical sensors

    Science.gov (United States)

    Majoo, Sanjeev

    Recent advances in microelectronics and silicon processing have been exploited to fabricate miniaturized chemical sensors. Although the capability of chemical sensing technology has grown steadily, it has been outpaced by the increasing demands for more reliable, inexpensive, and selective sensors. The diversity of applications requires the deployment of different sensing materials that have rich interfacial chemistry. However, several promising sensor materials are often incompatible with silicon micromachining and their deposition requires complicated masking steps. The new approach described here is to first micromachine a generic, instrumented, conductometric, microelectronic sensor platform that is fully functional except for the front-end sensing element. This generic platform contains a thin dielectric membrane, an integrated boron-doped silicon heater, and conductance electrodes. The membrane has low thermal mass and excellent thermal isolation. A proprietary selected-area chemical vapor deposition (SACVD) process in a cold-wall reactor at low pressures was then used to achieve maskless, self-lithographic deposition of thin films. The temperature-programmable integrated microheater initiates localized thermal decomposition/reaction of suitable CVD precursors confined to a small heated area (500 mum in diameter), and this creates the active sensing element. Platinum and titania (TiOsb2) films were deposited from pyrolysis of organometallic precursors, tetrakistrifluorophosphine platinum Pt(PFsb3)sb4 and titanium tetraisopropoxide Ti(OCH(CHsb3)sb2rbrack sb4, respectively. Deposition of gold metal films from chlorotriethylphosphine gold (Csb2Hsb5)sb3PAuCl precursor was also attempted but without success. The conductance electrodes permit in situ monitoring of film growth. The as-deposited films were characterized in situ by conductance measurements and optical microscopy and ex situ by electron microscopy and spectroscopy methods. Devices equipped with

  12. Noninvasive blood pressure measurement scheme based on optical fiber sensor

    Science.gov (United States)

    Liu, Xianxuan; Yuan, Xueguang; Zhang, Yangan

    2016-10-01

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

  13. New Optical Sensor Suite for Ultrahigh Temperature Fossil Fuel Application

    Energy Technology Data Exchange (ETDEWEB)

    John Coggin; Tom Flynn; Jonas Ivasauskas; Daniel Kominsky; Carrie Kozikowski; Russell May; Michael Miller; Tony Peng; Gary Pickrell; Raymond Rumpf; Kelly Stinson-Bagby; Dan Thorsen; Rena Wilson

    2007-12-31

    Accomplishments of a program to develop and demonstrate photonic sensor technology for the instrumentation of advanced powerplants and solid oxide fuel cells are described. The goal of this project is the research and development of advanced, robust photonic sensors based on improved sapphire optical waveguides, and the identification and demonstration of applications of the new sensors in advanced fossil fuel power plants, where the new technology will contribute to improvements in process control and monitoring.

  14. Zeonex Microstructured Polymer Optical Fibre Bragg Grating Sensor

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Fasano, Andrea; Markos, Christos

    2016-01-01

    We fabricated an endlessly single mode and humidity insensitive Zeonex microstructured polymer optical fibre (mPOF) for fibre Bragg grating (FBG) temperature and strain sensors. We inscribed and characterise FBGs in Zeonex mPOF for the first time.......We fabricated an endlessly single mode and humidity insensitive Zeonex microstructured polymer optical fibre (mPOF) for fibre Bragg grating (FBG) temperature and strain sensors. We inscribed and characterise FBGs in Zeonex mPOF for the first time....

  15. Modal Frequency Detection in Composite Beams Using Fiber Optic Sensors

    Science.gov (United States)

    2011-07-28

    interference have been developed. These include the Fabry-Perot interferometer , the Mach-Zehner interferometer , and the Michelson interferometer [8]. The...widely studied. A Fabry-Perot interferometer as a fiber optic sensor was first introduced in 1982 [10]. In a later study intrinsic Fabry-Perot...Yoshino, Kiyoshi Kurosawa, Katsuji Itoh, and Teruzi Ose, " Fiber -Optic Fabry-Perot Interferometer and its Sensor Applications," IEEE Journal of Quantum

  16. Review Of Fiber-Optic Electric-Field Sensors

    Science.gov (United States)

    De Paula, Ramon P.; Jarzynski, Jacek

    1989-01-01

    Tutorial paper reviews state of art in fiber-optic sensors of alternating electric fields. Because such sensors are made entirely of dielectric materials, they are relatively transparent to incident electric fields; they do not distort fields significantly. Paper presents equations that express relationships among stress, strain, and electric field in piezoactive plastic and equations for phase shift in terms of photoelastic coefficients and strains in optical fiber.

  17. Network Integration of Distributed Optical Fiber Temperature Sensor

    Institute of Scientific and Technical Information of China (English)

    Gui-Yan Li; Hong-Lin Liu; Zai-Xuan Zhang

    2008-01-01

    The integration of distributed optical fiber temperature sensor with supervisory control and data acquisition (SCADA) system is proposed and implemented. In the implementation of the integration, both the compatibility with traditional system and the characteristics of distributed optical fiber temperature sensor is considered before Modbus TCP/IP protocol is chosen. The protocol is implemented with open source component Indy. The Modbus TCP/IP protocol used in the system is proved to be fast and robust.

  18. Utilization of biosensors and chemical sensors for space applications

    Science.gov (United States)

    Bonting, S. L.

    1992-01-01

    There will be a need for a wide array of chemical sensors for biomedical experimentation and for the monitoring of water and air recycling processes on Space Station Freedom. The infrequent logistics flights of the Space Shuttle will necessitate onboard analysis. The advantages of biosensors and chemical sensors over conventional analysis onboard spacecraft are manifold. They require less crew time, space, and power. Sample treatment is not needed. Real time or near-real time monitoring is possible, in some cases on a continuous basis. Sensor signals in digitized form can be transmitted to the ground. Types and requirements for chemical sensors to be used in biomedical experimentation and monitoring of water recycling during long-term space missions are discussed.

  19. Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

    Directory of Open Access Journals (Sweden)

    Dora M. Paolucci

    2011-03-01

    Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

  20. A new remote optical wetness sensor and its applications

    NARCIS (Netherlands)

    Heusinkveld, B.G.; Berkowicz, S.M.; Jacobs, A.F.G.; Hillen, W.C.A.M.; Holtslag, A.A.M.

    2008-01-01

    An optical wetness sensor (OWS) was developed for continuous surface wetness measurements. The sensor is an all-weather instrument that does not interfere with the surface wetting and drying process and is unaffected by solar radiation. It is equipped with its own light source with which it can scan

  1. Realization and characterization of fiber optic reflective sensor

    Science.gov (United States)

    Guzowski, B.; Łakomski, M.; Słapek, B.

    2016-11-01

    In almost all of non-invasive techniques, fiber optic sensors may be the most promising ones because of their inherent advantages such as very small size and hard environment tolerance. Proximity sensors based on optical fiber are highly required especially in the impact area of electromagnetic fields. In this paper three different types of fiber optic reflective sensors are presented. In all three types of the sensor four multimode optical fibers (MMF) illuminate the movable surface. The difference is in the number of collecting the reflected light MMF. In the first one, 12 MMF collect the light, in the second one 20 MMF, while in the third one the number of MMF collecting reflected light is 32. Moreover, all three types of fiber optic reflective sensors were realized in two configurations. In the first one, the cleaved MMF were used to collect reflected light, while in the second configuration - the ball-lensed optical fibers were chosen. In this paper an analysis of each type of realized sensor is presented. In the last part of this paper the obtained results and the detailed discussion are given.

  2. Chemical Sensors Based on Piezoresistive Cantilever Array

    Institute of Scientific and Technical Information of China (English)

    于晓梅; 张大成; 王丛舜; 杜先锋; 王小宝; 阮勇

    2003-01-01

    U-shaped and rectangle piezoresistive cantilever arrays have been designed with the analysing results of stress,noise and sensitivity of the cantilevers. Based on silicon micromachining technology, the piezoresistive cantilevers were fabricated by using polysilicon as the piezoresistive materials. With the measurement results of noise and sensitivity, the Hooge factor is calculated to be 3 × 10-3, the gauge factor is 27, and the minimum detectable deflection of piezoresistive cantilevers are calculated to be 1.0nm for rectangle cantilever and 0.5 nm for the Ushaped cantilever at a 6 V bias voltage and a 1000 Hz measurement bandwidth. Using polymer-coated cantilevers as individual sensors, their responses to water vapour and ammonia were tested by measuring their output voltage signals. The measured results show that the sensor sensitivity to ammonia can reach a few ppm and the sensor responses are quick.

  3. Fiber optic and laser sensors V; Proceedings of the Meeting, San Diego, CA, Aug. 17-19, 1987

    Science.gov (United States)

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

    1988-01-01

    The papers contained in this volume focus on recent developments in fiber optic and laser sensors. Topics discussed include electric and magnetic field sensors, fiber optic pressure sensors, fiber optic gyros, fiber optic sensors for aerospace applications, fiber sensor multiplexing, temperature sensors, and specialized fiber optic sensors. Papers are presented on remote fiber optic sensors for angular orientation; fiber optic rotation sensor for space missions; adaptation of an electro-optic monitoring system to aerospace structures; optical fiber sensor for dust concentration measurements; and communication-sensing system using a single optical fiber.

  4. A new class of optical sensors: a random laser based device

    Science.gov (United States)

    Ignesti, Emilio; Tommasi, Federico; Fini, Lorenzo; Martelli, Fabrizio; Azzali, Niccolò; Cavalieri, Stefano

    2016-10-01

    In a random laser the optical feedback is provided by scattering rather than by an optical cavity. Then, since its emission characteristics are very susceptible to the scattering details, it is a natural candidate for making active sensors to use as a diagnostic tool for disordered media like biological samples. However, the methods reported up to now, requiring the injection of toxic substances in the sample, have the drawback of altering the physical-chemical composition of the medium and are not suitable for in-vivo measurements. Here we present a random laser based sensor that overcomes these problems by keeping gain and diffusion separated. We provide an experimental characterisation of the sensor by using a reference diffusive liquid phantom and we show that, compared to a passive method, this sensor takes advantage of the gain and spectral properties of the random laser principle.

  5. A new class of optical sensors: a random laser based device.

    Science.gov (United States)

    Ignesti, Emilio; Tommasi, Federico; Fini, Lorenzo; Martelli, Fabrizio; Azzali, Niccolò; Cavalieri, Stefano

    2016-10-11

    In a random laser the optical feedback is provided by scattering rather than by an optical cavity. Then, since its emission characteristics are very susceptible to the scattering details, it is a natural candidate for making active sensors to use as a diagnostic tool for disordered media like biological samples. However, the methods reported up to now, requiring the injection of toxic substances in the sample, have the drawback of altering the physical-chemical composition of the medium and are not suitable for in-vivo measurements. Here we present a random laser based sensor that overcomes these problems by keeping gain and diffusion separated. We provide an experimental characterisation of the sensor by using a reference diffusive liquid phantom and we show that, compared to a passive method, this sensor takes advantage of the gain and spectral properties of the random laser principle.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  7. Transparent and flexible force sensor array based on optical waveguide.

    Science.gov (United States)

    Kim, Youngsung; Park, Suntak; Park, Seung Koo; Yun, Sungryul; Kyung, Ki-Uk; Sun, Kyung

    2012-06-18

    This paper suggests a force sensor array measuring contact force based on intensity change of light transmitted throughout optical waveguide. For transparency and flexibility of the sensor, two soft prepolymers with different refractive index have been developed. The optical waveguide consists of two cladding layers and a core layer. The top cladding layer is designed to allow light scattering at the specific area in response to finger contact. The force sensor shows a distinct tendency that output intensity decreases with input force and measurement range is from 0 to -13.2 dB.

  8. Plastic optical fibre sensor for quality control in food industry

    Science.gov (United States)

    Novo, C.; Bilro, L.; Ferreira, R.; Alberto, N.; Antunes, P.; Leitão, C.; Nogueira, R.; Pinto, J. L.

    2013-05-01

    The present work addresses the need for new devices felt in the context of quality control, especially in the food industry. Due to the spectral dependence of the attenuation coefficient, a novel dual-parameter sensor for colour and refractive index was developed and tested. The sensor employs plastic optical fibres to measure the transmitted optical power in three measurement cells each with a different incident wavelength. The performance of the sensor was tested using several dyes at different concentrations and aqueous solutions of glycerine and ethanol. Results show that this technique allows the monitoring of refractive index and colour without cross-sensitivity.

  9. Optical Pressure-Temperature Sensor for a Combustion Chamber

    Science.gov (United States)

    Wiley, John; Korman, Valentin; Gregory, Don

    2008-01-01

    A compact sensor for measuring temperature and pressure in a combusti on chamber has been proposed. The proposed sensor would include two optically birefringent, transmissive crystalline wedges: one of sapph ire (Al2O3) and one of magnesium oxide (MgO), the optical properties of both of which vary with temperature and pressure. The wedges wou ld be separated by a vapor-deposited thin-film transducer, which wou ld be primarily temperaturesensitive (in contradistinction to pressur e- sensitive) when attached to a crystalline substrate. The sensor w ould be housed in a rugged probe to survive the extreme temperatures and pressures in a combustion chamber.

  10. Evaluation of chemical sensors for in situ ground-water monitoring at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, E.M.; Hostetler, D.D.

    1989-03-01

    This report documents a preliminary review and evaluation of instrument systems and sensors that may be used to detect ground-water contaminants in situ at the Hanford Site. Three topics are covered in this report: (1) identification of a group of priority contaminants at Hanford that could be monitored in situ, (2) a review of current instrument systems and sensors for environmental monitoring, and (3) an evaluation of instrument systems that could be used to monitor Hanford contaminants. Thirteen priority contaminants were identified in Hanford ground water, including carbon tetrachloride and six related chlorinated hydrocarbons, cyanide, methyl ethyl ketone, chromium (VI), fluoride, nitrate, and uranium. Based on transduction principles, chemical sensors were divided into four classes, ten specific types of instrument systems were considered: fluorescence spectroscopy, surface-enhanced Raman spectroscopy (SERS), spark excitation-fiber optic spectrochemical emission sensor (FOSES), chemical optrodes, stripping voltammetry, catalytic surface-modified ion electrode immunoassay sensors, resistance/capacitance, quartz piezobalance and surface acoustic wave devices. Because the flow of heat is difficult to control, there are currently no environmental chemical sensors based on thermal transduction. The ability of these ten instrument systems to detect the thirteen priority contaminants at the Hanford Site at the required sensitivity was evaluated. In addition, all ten instrument systems were qualitatively evaluated for general selectivity, response time, reliability, and field operability. 45 refs., 23 figs., 7 tabs.

  11. A Miniaturized Optical Sensor with Integrated Gas Cell

    NARCIS (Netherlands)

    Ayerden, N.P.; Ghaderi, M.; De Graaf, G.; Wolffenbuttel, R.F.

    2015-01-01

    The design, fabrication and characterization of a highly integrated optical gas sensor is presented. The gas cell takes up most of the space in a microspectrometer and is the only component that has so far not been miniaturized. Using the tapered resonator cavity of a linear variable optical filter

  12. Future electro-optical sensors and processing in urban operations

    NARCIS (Netherlands)

    Grönwall, C.; Schwering, P.B.; Rantakokko, J.; Benoist, K.W.; Kemp, R.A.W.; Steinvall, O.; Letalick, D.; Björkert, S.

    2013-01-01

    In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of

  13. Distributed Fiber-Optic Sensors for Vibration Detection.

    Science.gov (United States)

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

    2016-07-26

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

  14. Shack-Hartmann sensor improvement using optical binning

    CERN Document Server

    Basden, Alastair; Guzman, Dani; Morris, Tim; Myers, Richard; Saunter, Chris

    2007-01-01

    We present a design improvement for a recently proposed type of Shack-Hartmann wavefront sensor that uses a cylindrical (lenticular) lenslet array. The improved sensor design uses optical binning and requires significantly fewer detector pixels than the corresponding conventional or cylindrical Shack-Hartmann sensor, and so detector readout noise causes less signal degradation. Additionally, detector readout time is significantly reduced, which reduces the latency for closed loop systems, and data processing requirements. We provide simple analytical noise considerations and Monte-Carlo simulations, and show that the optically binned Shack-Hartmann sensor can offer better performance than the conventional counterpart in most practical situations, and our design is particularly suited for use with astronomical adaptive optics systems.

  15. A novel optical sensor for mirror edge sensing

    Science.gov (United States)

    Buckley, D. A. H.; Buous, S.; Gajjar, H.; Menzies, J. W.; Schindler, F.; Sändig, K.; Lév"que, S.

    2010-07-01

    The Southern African Large Telescope (SALT) recently (2008) abandoned attempts at using capacitive mirror edge sensors, mainly due to poor performance at a relative humidity above ~60%, a not infrequent occurrence. Different technologies are now being explored for alternative sensors on SALT. In this paper we describe the design and development of a novel prototype optical edge sensor, based on the application of the interferential scanning principle, as used in optical encoders. These prototype sensors were subsequently tested at SAAO and ESO, for potential application on SALT and E-ELT. Environmental tests, conducted in climatic control chambers, looked at temperature and relative humidity sensitivity, long term stability and sensor noise. The temperature sensitivity for height and gap were, respectively, 10nm/°C and 44nm/°C, while for relative humidity they were 4nm/10% and 50nm/10%, respectively. These either met, or were close to, the SALT specification. While there were significant lags in response, this was due to the sensor's relatively large mass (~200 gm per sensor half), which was not optimized. This is likely to improve, should a revised design be developed in future. Impressively the sensor noise was <0.015 nm RMS, over three orders of magnitude better than the specification. Our conclusions are that optical edge sensing is a viable technique for use on segmented mirror telescopes.

  16. Intrinsic Fabry-Perot optical fiber sensors and their multiplexing

    Science.gov (United States)

    Wang, Anbo

    2007-12-11

    An intrinsic Fabry-Perot optical sensor includes a thin film sandwiched between two fiber ends. When light is launched into the fiber, two reflections are generated at the two fiber/thin film interfaces due to a difference in refractive indices between the fibers and the film, giving rise to the sensor output. In another embodiment, a portion of the cladding of a fiber is removed, creating two parallel surfaces. Part of the evanescent fields of light propagating in the fiber is reflected at each of the surfaces, giving rise to the sensor output. In a third embodiment, the refractive index of a small portion of a fiber is changed through exposure to a laser beam or other radiation. Interference between reflections at the ends of the small portion give rise to the sensor output. Multiple sensors along a single fiber are multiplexed using an optical time domain reflectometry method.

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

    Directory of Open Access Journals (Sweden)

    Jianping Yao

    2011-03-01

    Full Text Available 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.

  18. Design and Deployment of Low-Cost Plastic Optical Fiber Sensors for Gas Monitoring

    Directory of Open Access Journals (Sweden)

    Sabrina Grassini

    2014-12-01

    Full Text Available This paper describes an approach to develop and deploy low-cost plastic optical fiber sensors suitable for measuring low concentrations of pollutants in the atmosphere. The sensors are designed by depositing onto the exposed core of a plastic fiber thin films of sensitive compounds via either plasma sputtering or via plasma-enhanced chemical vapor deposition (PECVD. The interaction between the deposited layer and the gas alters the fiber’s capability to transmit the light, so that the sensor can simply be realized with a few centimeters of fiber, an LED and a photodiode. Sensors arranged in this way exhibit several advantages in comparison to electrochemical and optical conventional sensors; in particular, they have an extremely low cost and can be easily designed to have an integral, i.e., cumulative, response. The paper describes the sensor design, the preparation procedure and two examples of sensor prototypes that exploit a cumulative response. One sensor is designed for monitoring indoor atmospheres for cultural heritage applications and the other for detecting the presence of particular gas species inside the RPC (resistive plate chamber muon detector of the Compact Muon Solenoid (CMS experiment at CERN in Geneva.

  19. Comparison of active microwave and optical sensors

    NARCIS (Netherlands)

    Schwering, P.B.W.; Theil, A.

    2002-01-01

    This paper describes a number of projects at TNO-FEL in the field of sensor fusion of radar and electrooptical sensors. These fusion approaches consider land, air, and maritime scenarios for surveillance and autonomous detection tasks. Fusion benefits are present when uncorrelated and complementary

  20. Carbon Nanotube-Based Chemical Sensors.

    Science.gov (United States)

    Meyyappan, M

    2016-04-27

    The need to sense gases and vapors arises in numerous scenarios in industrial, environmental, security and medical applications. Traditionally, this activity has utilized bulky instruments to obtain both qualitative and quantitative information on the constituents of the gas mixture. It is ideal to use sensors for this purpose since they are smaller in size and less expensive; however, their performance in the field must match that of established analytical instruments in order to gain acceptance. In this regard, nanomaterials as sensing media offer advantages in sensitivity, preparation of chip-based sensors and construction of electronic nose for selective detection of analytes of interest. This article provides a review of the use of carbon nanotubes in gas and vapor sensing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Double-Tubing Encapsulated Fiber Optic Temperature Sensor

    Science.gov (United States)

    Xu, Juncheng; Pickrell, Gary; Huang, Zhengyu; Qi, Bing; Zhang, Po; Duan, Yuhong; Wang, Anbo

    2003-09-01

    Increasing the efficiency of oil production operations requires improved sensors to supply critical information such as mixed-phase fluid flow, pressure and temperature measurements within the down-hole oil environment. In order to provide robust and reliable fiber optic temperature sensors capable of operating in the harsh down-hole oil environment, where temperatures might exceed 250 °C and pressures might reach 20,000 psi (140 Mpa), a novel type of fiber optic temperature sensor has been developed. This temperature sensor functions as an EFPI (extrinsic Fabry-Perot interferometric) sensor. One unique contribution of this work is that the glass tubing used is a borosilicate glass with a relatively high coefficient of thermal expansion (CTE) and long gauge length, allowing a much higher sensitivity to be achieved, without hysteresis. The sensor structure utilizes a dual tubing design (tubing within a tubing) to allow pressure isolation. An LED light beam is used as the signal interrogation source to remotely interrogate the sensor which may be located tens of thousands of meters away, connected by an optical fiber. A white-light interferometer measurement system is utilized to process the returned interference signal and to precisely determine the length of the Fabry-Perot interferometric cavity. Another unique feature of this work is that the sensor has been packaged with a specially developed hermetic protection process to prevent water penetration and to improve the mechanical integrity of the sensor. This protection process has allowed the successful hydraulic deployment of fiber optic sensors through 3 mm ID stainless steel tubing into a functioning oil well. Data on the resolution, repeatability and pressure sensitivity are presented.

  2. Experimental Investigation of Integrated Optical Intensive Impulse Electric Field Sensors

    Institute of Scientific and Technical Information of China (English)

    SUN Bao; CHEN Fu-Shen

    2009-01-01

    We design and fabricate an integrated optical electric field sensor with segmented electrode for intensive im-pulse electric field measurement. The integrated optical sensor is based on a Mach-Zehnder interferometer with segmented electrodes. The output/input character of the sensing system is analysed and measured. The max-imal detectable electric field range (-75 kV/m to 245 kV/m) is obtained by analysing the results. As a result, the integrated optics electric field sensing system is suitable for transient intensive electric field measurement investigation.

  3. Distributed optical fiber dynamic magnetic field sensor based on magnetostriction.

    Science.gov (United States)

    Masoudi, Ali; Newson, Trevor P

    2014-05-01

    A distributed optical fiber sensor is introduced which is capable of quantifying multiple magnetic fields along a 1 km sensing fiber with a spatial resolution of 1 m. The operation of the proposed sensor is based on measuring the magnetorestrictive induced strain of a nickel wire attached to an optical fiber. The strain coupled to the optical fiber was detected by measuring the strain-induced phase variation between the backscattered Rayleigh light from two segments of the sensing fiber. A magnetic field intensity resolution of 0.3 G over a bandwidth of 50-5000 Hz was demonstrated.

  4. Solution-gated graphene transistors for chemical and biological sensors.

    Science.gov (United States)

    Yan, Feng; Zhang, Meng; Li, Jinhua

    2014-03-01

    Graphene has attracted much attention in biomedical applications for its fascinating properties. Because of the well-known 2D structure, every atom of graphene is exposed to the environment, so the electronic properties of graphene are very sensitive to charged analytes (ions, DNA, cells, etc.) or an electric field around it, which renders graphene an ideal material for high-performance sensors. Solution-gated graphene transistors (SGGTs) can operate in electrolytes and are thus excellent candidates for chemical and biological sensors, which have been extensively studied in the recent 5 years. Here, the device physics, the sensing mechanisms, and the performance of the recently developed SGGT-based chemical and biological sensors, including pH, ion, cell, bacterial, DNA, protein, glucose sensors, etc., are introduced. Their advantages and shortcomings, in comparison with some conventional techniques, are discussed. Conclusions and challenges for the future development of the field are addressed in the end.

  5. Polymer Optical Fiber Sensor and the Prediction of Sensor Response Utilizing Artificial Neural Networks

    Science.gov (United States)

    Haroglu, Derya

    The global market researches showed that there is a growing trend in the field of polymer optical fiber (POF) and POF sensors. Telecommunications, medicine, defense, aerospace, and automotive are the application areas of fiber optic sensors, where the automotive industry is the most promising application area for innovations in the field of POF sensors. The POF sensors in automobiles are particularly for detection of seat occupancy, and intelligent pedestrian protection systems. This dissertation investigates graded index perfluorinated polymer optical fiber as an intensity modulated intrinsic sensor for application in automotive seat occupancy sensing. Since a fiber optic sensor has a high bandwidth, is small in size, is lightweight, and is immune to electromagnetic interference (EMI) it offers higher performance than that of its electrical based counterparts such as strain gauge, elastomeric bladder, and resistive sensor systems. This makes the fiber optic sensor a potential suitable material for seat occupancy sensing. A textile-based fiber optic sensor was designed to be located in the area beneath the typical seated human's thighs. The pressure interval under which the proposed POF sensor design could perform well was found to be between 0.18 and 0.21 N/cm2, where perfluorinated (PF) graded index (GI) POF (62.5/750 mum) was used as the POF material. In addition, the effect of the automotive seat covering including face material (fabric) and foam backing to the sensor's performance was analyzed. The face fabric structure and the thickness of foam backing were not found to be significant factors to change the sensor results. A research study, survey, was conducted of which purpose was to better understand market demands in terms of sensor performance characteristics for automotive seat weight sensors, as a part of the Quality Function Deployment (QFD) House of Quality analysis. The companies joined the survey agreed on the first 5 most important sensor

  6. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Zhenzhong Guo

    2016-10-01

    Full Text Available The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclusion and future expectations are described herein.

  7. Molecularly Imprinted Polymer/Metal Organic Framework Based Chemical Sensors

    OpenAIRE

    Zhenzhong Guo; Anca Florea; Mengjuan Jiang; Yong Mei; Weiying Zhang; Aidong Zhang; Robert Săndulescu; Nicole Jaffrezic-Renault

    2016-01-01

    The present review describes recent advances in the concept of molecular imprinting using metal organic frameworks (MOF) for development of chemical sensors. Two main strategies regarding the fabrication, performance and applications of recent sensors based on molecularly imprinted polymers associated with MOF are presented: molecularly imprinted MOF films and molecularly imprinted core-shell nanoparticles using MOF as core. The associated transduction modes are also discussed. A brief conclu...

  8. Synchronous phase detection for optical fiber interferometric sensors.

    Science.gov (United States)

    Bush, I J; Phillips, R L

    1983-08-01

    A system has been developed to accurately detect phase signals produced in optical interferometric sensors. The system employs optical heterodyning and synchronously detects optical phase by feeding back an error signal to a phase modulator in the reference leg of the interferometer. This system is seen to have properties similar to a phase-locked loop. The system is mathematically analyzed and a simple second-order model developed which accurately predicts the system response.

  9. Chemical sensor with oscillating cantilevered probe

    Science.gov (United States)

    Adams, Jesse D

    2013-02-05

    The invention provides a method of detecting a chemical species with an oscillating cantilevered probe. A cantilevered beam is driven into oscillation with a drive mechanism coupled to the cantilevered beam. A free end of the oscillating cantilevered beam is tapped against a mechanical stop coupled to a base end of the cantilevered beam. An amplitude of the oscillating cantilevered beam is measured with a sense mechanism coupled to the cantilevered beam. A treated portion of the cantilevered beam is exposed to the chemical species, wherein the cantilevered beam bends when exposed to the chemical species. A second amplitude of the oscillating cantilevered beam is measured, and the chemical species is determined based on the measured amplitudes.

  10. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  11. New Nanomaterials and Luminescent Optical Sensors for Detection of Hydrogen Peroxide

    Directory of Open Access Journals (Sweden)

    Natalia A. Burmistrova

    2015-10-01

    Full Text Available Accurate methods that can continuously detect low concentrations of hydrogen peroxide (H2O2 have a huge application potential in biological, pharmaceutical, clinical and environmental analysis. Luminescent probes and nanomaterials are used for fabrication of sensors for H2O2 that can be applied for these purposes. In contrast to previous reviews focusing on the chemical design of molecular probes for H2O2, this mini-review highlights the latest luminescent nanoparticular materials and new luminescent optical sensors for H2O2 in terms of the nanomaterial composition and luminescent receptor used in the sensors. The nanomaterial section is subdivided into schemes based on gold nanoparticles, polymeric nanoparticles with embedded enzymes, probes showing aggregation-induced emission enhancement, quantum dots, lanthanide-based nanoparticles and carbon based nanomaterials, respectively. Moreover, the sensors are ordered according to the type of luminescent receptor used within the sensor membranes. Among them are lanthanide complexes, metal-ligand complexes, oxidic nanoparticles and organic dyes. Further, the optical sensors are confined to those that are capable to monitor the concentration of H2O2 in a sample over time or are reusable. Optical sensors responding to gaseous H2O2 are not covered. All nanomaterials and sensors are characterized with respect to the analytical reaction towards H2O2, limit of detection (LOD, analytical range, electrolyte, pH and response time/incubation time. Applications to real samples are given. Finally, we assess the suitability of the nanomaterials to be used in membrane-based sensors and discuss future trends and perspectives of these sensors in biomedical research.

  12. The Application of Metal Oxide Nanomaterials for Chemical Sensor Development

    Science.gov (United States)

    Xu, Jennifer C.; Hunter, Gary W.; Evans, Laura J.; VanderWal, Randy L.; Berger, Gordon M.

    2007-01-01

    NASA Glenn Research Center (GRC) has been developing miniature chemical sensors for a variety of applications including fire detection, emissions monitoring, fuel leak detection, and environmental monitoring. Smart Lick and Stick sensor technology which integrates a sensor array, electronics, telemetry, and power into one microsystem are being developed. These microsystems require low power consumption for long-term aerospace applications. One approach to decreasing power consumption is the use of nanotechnology. Nanocrystalline tin oxide (SnO2) carbon monoxide (CO) sensors developed previously by this group have been successfully used for fire detection and emissions monitoring. This presentation will briefly review the overall NASA GRC chemical sensor program and discuss our further effort in nanotechnology applications. New carbon dioxide (CO2) sensing material using doped nanocrystalline SnO2 will be discussed. Nanocrystalline SnO2 coated solid electrolyte CO2 sensors and SnO2 nanorod and nanofiber hydrogen (H2) sensors operated at reduced or room temperatures will also be discussed.

  13. Direct Push Chemical Sensors for DNAPL

    Science.gov (United States)

    2007-01-01

    SPOC ) ........................................... 39 2.2.2.1.4 Emission detection system...Decay from all 4 PAHs Figure 11. Temporal fluorescence examples Of course the fluorescence decay profile observed in sediments is not made up of...fluorescence to the surface for measurement. Both fibers are SMA terminated at the surface. 39 2.2.2.1.3 Shock-protected optical compartment ( SPOC

  14. Free space optical sensor network for fixed infrastructure sensing

    Science.gov (United States)

    Agrawal, Navik; Milner, Stuart D.; Davis, Christopher C.

    2009-08-01

    Free space optical (FSO) links for indoor sensor networks can provide data rates that can range from bits/s to hundreds of Mb/s. In addition, they offer physical security, and in contrast with omnidirectional RF networks, they avoid interference with other electronic systems. These features are advantageous for communication over short distances in fixed infrastructure sensor networks. In this paper the system architecture for a fixed infrastructure FSO sensor network is presented. The system includes a network of small, low power (mW), sensor systems, or "motes," that transmit data optically to a central "cluster head," which controls the network traffic of all the motes and can aggregate the sensor information. The cluster head is designed with multiple vertical cavity surface emitting lasers oriented in different directions and controlled to diverge at 12º in order to provide signal coverage over a wide field of view. Both the cluster head and motes form a local area network. Our system design focuses on low-power wireless motes that can maintain successful communication over distances up to a few meters without having to use stringent optical alignment techniques, and our network design focuses on controlling mote sleep cycles for energy efficiency. This paper presents the design as well as the experimental link and optical communications performance of a prototype FSO-based sensor network.

  15. NEW OPTICAL SENSOR SUITE FOR ULTRAHIGH TEMPERATURE FOSSIL FUEL APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Russell G. May; Tony Peng; Tom Flynn

    2004-12-01

    Accomplishments during the Phase I of a program to develop and demonstrate technology for the instrumentation of advanced powerplants are described. Engineers from Prime Research, LC and Babcock and Wilcox Research Center collaborated to generate a list of potential applications for robust photonic sensors in existing and future boiler plants. From that list, three applications were identified as primary candidates for initial development and demonstration of high-temperature sensors in an ultrasupercritical power plant. A matrix of potential fiber optic sensor approaches was derived, and a data set of specifications for high-temperature optical fiber was produced. Several fiber optic sensor configurations, including interferometric (extrinsic and intrinsic Fabry-Perot interferometer), gratings (fiber Bragg gratings and long period gratings), and microbend sensors, were evaluated in the laboratory. In addition, progress was made in the development of materials and methods to apply high-temperature optical claddings to sapphire fibers, in order to improve their optical waveguiding properties so that they can be used in the design and fabrication of high-temperature sensors. Through refinements in the processing steps, the quality of the interface between core and cladding of the fibers was improved, which is expected to reduce scattering and attenuation in the fibers. Numerical aperture measurements of both clad and unclad sapphire fibers were obtained and used to estimate the reduction in mode volume afforded by the cladding. High-temperature sensors based on sapphire fibers were also investigated. The fabrication of an intrinsic Fabry-Perot cavity within sapphire fibers was attempted by the bulk diffusion of magnesium oxide into short localized segments of longer sapphire fibers. Fourier analysis of the fringes that resulted when the treated fiber was interrogated by a swept laser spectrometer suggested that an intrinsic cavity had been formed in the fiber. Also

  16. SMART composite high pressure vessels with integrated optical fiber sensors

    Science.gov (United States)

    Blazejewski, Wojciech; Czulak, Andrzej; Gasior, Pawel; Kaleta, Jerzy; Mech, Rafal

    2010-04-01

    In this paper application of integrated Optical Fiber Sensors for strain state monitoring of composite high pressure vessels is presented. The composite tanks find broad application in areas such as: automotive industry, aeronautics, rescue services, etc. In automotive application they are mainly used for gaseous fuels storage (like CNG or compressed Hydrogen). In comparison with standard steel vessels, composite ones have many advantages (i.e. high mechanical strength, significant weight reduction, etc). In the present work a novel technique of vessel manufacturing, according to this construction, was applied. It is called braiding technique, and can be used as an alternative to the winding method. During braiding process, between GFRC layers, two types of optical fiber sensors were installed: point sensors in the form of FBGs as well as interferometric sensors with long measuring arms (SOFO®). Integrated optical fiber sensors create the nervous system of the pressure vessel and are used for its structural health monitoring. OFS register deformation areas and detect construction damages in their early stage (ensure a high safety level for users). Applied sensor system also ensured a possibility of strain state monitoring even during the vessel manufacturing process. However the main application of OFS based monitoring system is to detect defects in the composite structure. An idea of such a SMART vessel with integrated sensor system as well as an algorithm of defect detection was presented.

  17. Label-Free Optical Biochemical Sensors via Liquid-Cladding-Induced Modulation of Waveguide Modes.

    Science.gov (United States)

    Tran, Nhu Hoa Thi; Kim, Jisoo; Phan, Thang Bach; Khym, Sungwon; Ju, Heongkyu

    2017-09-07

    We demonstrated modulation of the waveguide mode mismatch via liquid cladding of the controllable refractive index for label-free quantitative detection of concentration of chemical or biological substances. A multimode optical fiber with its core exposed was used as the sensor head with the suitable chemical modification of its surface. Injected analyte liquid itself formed the liquid cladding for the waveguide. We found that modulation of the concentration of analyte injected enables a degree of the waveguide mode mismatch to be controlled, resulting in sensitive change in optical power transmission, which was utilized for its real-time quantitative assay. We applied the device to quantitating concentration of glycerol and bovine serum albumin (BSA) solutions. We obtained experimentally the limit of detection (LOD) of glycerol concentration, 0.001% (volume ratio), corresponding to the resolvable index resolution of ∼1.02 × 10(-6) RIU (refractive index unit). The presented sensors also exhibited reasonably good reproducibility. In BSA detection, the sensor device response was sensitive to change in the refractive indices not only of liquid bulk but also of layers just above the sensing surface with higher sensitivity, providing the LOD experimentally as ∼3.7 ng/mL (mass coverage of ∼30 pg/mm(2)). A theoretical model was also presented to invoke both mode mismatch modulation and evanescent field absorption for understanding of the transmission change, offering a theoretical background for designing the sensor head structure for a given analyte. Interestingly, the device sensing length played little role in the important sensor characteristics such as sensitivity, unlike most of the waveguide-based sensors. This unraveled the possibility of realizing a highly simple structured label-free sensor for point-of-care testing in a real-time manner via an optical waveguide with liquid cladding. This required neither metal nor dielectric coating but still produced

  18. Miniaturised wireless smart tag for optical chemical analysis applications.

    Science.gov (United States)

    Steinberg, Matthew D; Kassal, Petar; Tkalčec, Biserka; Murković Steinberg, Ivana

    2014-01-01

    A novel miniaturised photometer has been developed as an ultra-portable and mobile analytical chemical instrument. The low-cost photometer presents a paradigm shift in mobile chemical sensor instrumentation because it is built around a contactless smart card format. The photometer tag is based on the radio-frequency identification (RFID) smart card system, which provides short-range wireless data and power transfer between the photometer and a proximal reader, and which allows the reader to also energise the photometer by near field electromagnetic induction. RFID is set to become a key enabling technology of the Internet-of-Things (IoT), hence devices such as the photometer described here will enable numerous mobile, wearable and vanguard chemical sensing applications in the emerging connected world. In the work presented here, we demonstrate the characterisation of a low-power RFID wireless sensor tag with an LED/photodiode-based photometric input. The performance of the wireless photometer has been tested through two different model analytical applications. The first is photometry in solution, where colour intensity as a function of dye concentration was measured. The second is an ion-selective optode system in which potassium ion concentrations were determined by using previously well characterised bulk optode membranes. The analytical performance of the wireless photometer smart tag is clearly demonstrated by these optical absorption-based analytical experiments, with excellent data agreement to a reference laboratory instrument.

  19. Glidersonde, a Meteorological Optical Profiling Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The "Glidersonde"is a UAV-deployed environmental sensor suite that is air-deployed and glides into denied or hazardous areas including volcanoes or nuclear...

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

    Energy Technology Data Exchange (ETDEWEB)

    Kristie Cooper; Gary Pickrell; Anbo Wang

    2003-04-01

    This report summarizes technical progress over the fourth year of the ''Optical Fiber Sensor Technologies for Efficient and Economical Oil Recovery'' program, funded by the Federal Energy Technology Center 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. During the reporting period, research efforts under the program were focused on the development and evaluation of the fiber optic flow sensor system, and field testing in Tulsa, OK and the second field test of the pressure and temperature sensors in Coalinga, CA. The feasibility of a self-compensating fiber optic flow sensor based on a cantilever beam and interferometer for real-time flow rate measurements in the fluid filled pipes of oil field was clearly demonstrated. In addition, field testing of the pressure and temperature sensors deployed downhole continued. These accomplishments are summarized here: (1) Theoretical analysis and simulations were performed to ensure performance of the design. (2) The sensor fabrication and packaging techniques were investigated and improved. (3) Prototype flow sensors were fabricated based on the fabrication experience of hundreds of test sensors. (4) A lab-scale flow testing system was constructed and used for sensor evaluation. (5) Field-testing was performed in both the indoor and outdoor flow testing facility at the University of Tulsa, OK. (6) Testing of a multimode white light pressure and temperature sensor system continued at the oil site of Chevron/Texaco Company (Coalinga CA).

  1. Optically Defined Modal Sensors Incorporating Spiropyran-Doped Liquid Crystals with Piezoelectric Sensors

    Directory of Open Access Journals (Sweden)

    Hui-Lung Kuo

    2011-01-01

    Full Text Available We integrated a piezoelectric sensing layer lamina containing liquid crystals (LC and spiropyran (SP in a LC/SP mixture to create an optically reconfigurable modal sensor for a cantilever beam. The impedance of this LC/SP lamina was decreased by UV irradiation which constituted the underlying mechanism to modulate the voltage externally applied to the piezoelectric actuating layer. Illuminating a specific pattern onto the LC/SP lamina provided us with a way to spatially modulate the piezoelectric vibration signal. We showed that if an UV illuminated pattern matches the strain distribution of a specific mode, a piezoelectric modal sensor can be created. Since UV illumination can be changed in situ in real-time, our results confirm for the first time since the inception of smart sensors, that an optically tailored modal sensor can be created. Some potential applications of this type of sensor include energy harvesting devices, bio-chips, vibration sensing and actuating devices.

  2. Silicon nanowire field-effect chemical sensor

    NARCIS (Netherlands)

    Chen, Songyue

    2011-01-01

    This thesis describes the work that has been done on the project “Design and optimization of silicon nanowire for chemical sensing”, including Si-NW fabrication, electrical/electrochemical modeling, the application as ISFET, and the build-up of Si- NW/LOC system for automatic sample delivery. A nove

  3. Wearable Sensors for Chemical & Biological Detection

    Energy Technology Data Exchange (ETDEWEB)

    Ozanich, Richard M.

    2017-08-31

    One of PNNL’s strengths is the ability to conduct comprehensive technology foraging and objective assessments of various technology areas. The following examples highlight leading research by others in the area of chemical and biological (chem/bio) detection that could be further developed into a robust, highly integrated wearables to aid preparedness, response and recovery.

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

    Science.gov (United States)

    Lindner, Douglas K.; Reichard, Karl M.

    1991-01-01

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

  5. Multi-sensor control for precise assembly of optical components

    Institute of Scientific and Technical Information of China (English)

    Ma Li; Rong Weibin; Sun Lining

    2014-01-01

    In order to perform an optical assembly accurately, a multi-sensor control strategy is developed which includes an attitude measurement system, a vision system, a loss measurement system and a force sensor. A 3-DOF attitude measuring method using linear variable differential transformers (LVDT) is designed to adjust the relation of position and attitude between the spher-ical mirror and the resonator. A micro vision feedback system is set up to extract the light beam and the diaphragm, which can achieve the coarse positioning of the spherical mirror in the optical assembly process. A rapid self-correlation method is presented to analyze the spectrum signal for the fine positioning. In order to prevent the damage of the optical components and realize sealing of the resonator, a hybrid force-position control is constructed to control the contact force of the optical components. The experimental results show that the proposed multi-sensor control strategy succeeds in accomplishing the precise assembly of the optical components, which consists of parallel adjustment, macro coarse adjustment, macro approach, micro fine adjustment, micro approach and optical contact. Therefore, the results validate the multi-sensor control strategy.

  6. Multi-sensor control for precise assembly of optical components

    Directory of Open Access Journals (Sweden)

    Ma Li

    2014-06-01

    Full Text Available In order to perform an optical assembly accurately, a multi-sensor control strategy is developed which includes an attitude measurement system, a vision system, a loss measurement system and a force sensor. A 3-DOF attitude measuring method using linear variable differential transformers (LVDT is designed to adjust the relation of position and attitude between the spherical mirror and the resonator. A micro vision feedback system is set up to extract the light beam and the diaphragm, which can achieve the coarse positioning of the spherical mirror in the optical assembly process. A rapid self-correlation method is presented to analyze the spectrum signal for the fine positioning. In order to prevent the damage of the optical components and realize sealing of the resonator, a hybrid force-position control is constructed to control the contact force of the optical components. The experimental results show that the proposed multi-sensor control strategy succeeds in accomplishing the precise assembly of the optical components, which consists of parallel adjustment, macro coarse adjustment, macro approach, micro fine adjustment, micro approach and optical contact. Therefore, the results validate the multi-sensor control strategy.

  7. Magnetically guiding and orienting integrated chemical sensors

    Energy Technology Data Exchange (ETDEWEB)

    Anker, Jeffrey N., E-mail: janker@clemson.edu [Department of Chemistry and Center for Optical Materials Research and Engineering Technology (COMSET), Clemson University, Clemson, SC 29634 (United States); Lee, Yong-Eun Koo; Kopelman, Raoul [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States)

    2014-08-01

    Fluorescent microsensors for detecting pH and oxygen were positioned and oriented using magnetic tweezers. These multifunctional integrated microsensors were fabricated by physically linking together nano-components including magnetic nanoparticles, fluorescent nanoparticles, and metal hemisphere-shells. Two such microsensors are magnetic roll-shaped polystyrene particles with 120 nm fluorescent oxygen-sensing ormosil nanospheres that are physically pressed (“breaded”) into the roll surface, and 4–5 µm fluorescent microspheres that are capped with a 50 nm thick metal hemispherical shell. The magnetic tweezers consisted of an iron wire that was magnetized in an external magnetic field. Rotating this external field oriented and rotated the microsensors. - Highlights: • Multifunctional microsensors were fabricated by physically linking together nano-components. • Magnetic oxygen microsensors were fabricated with ratiometric fluorescence peaks. • Single sensors were rotated and translated using magnetic tweezers.

  8. Optical Fiber Sensor Technologies for Efficient and Economical Oil Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, a.; Pickrell, G.; Xiao, H.; May, r.

    2003-02-27

    The overall goal of this project was to develop reliable cost effective sensors for application in the down-hole environment. The physical parameters measured by these sensors were temperature, pressure, flow and acoustic signals. Sensor head configurations for each of the physical measurands were optimized to increase the sensitivity to the particular measurand of interest while decreasing the cross-sensitivity to the other physical measurands and to environmental influences. In addition, the optical signal demodulation electronics was designed to be insensitive to environmental influences while maintaining the required resolution, precision and accuracy of the parameter being sensed. The influence of potentially detrimental agents such as water in the down-hole environment was investigated as well as methods to protect both the optical fiber and the sensor from these detrimental effects.

  9. Two-interferometers fiber optic sensor for disturbance localization

    Science.gov (United States)

    Zyczkowski, Marek; Ciurapinski, Wieslaw; Kondrat, Marcin

    2005-09-01

    Initial researches of Two-interferometers Fibre Optic Sensor for Disturbance Localization will be presented. The sensor is typically susceptible to environmentally induced mechanical perturbation at low frequencies. The presented sensor consists of two interferometers: Sagnac and Michelson. The Sagnac transfer function is proportional to the product of two factors: firstly the rate of change, dφ/dt, of the optical signal, induced at a point by external disturbance, and secondly the distance between the disturbance point and the Sagnac coil centre. The second interferometer transfer function gives an output proportional to φ. So, if we determine a pulsation ω of the mechanical disturbance from both interferometers output signals, we will be able to localize point where the mechanical disturbance takes place along the fibre by means of simple division of these transfer function. A laboratory arrangement of the sensor and the results of numerical signal processing are also shown.

  10. Remote optical sensor system for E-field measurements

    Science.gov (United States)

    Heinzelmann, Robert; Stoehr, Andreas; Alder, Thomas; Kalinowski, D.; Schmidt, Manuel; Gross, Matthias; Jaeger, Dieter

    1998-12-01

    The concept of a remote optical sensor system for frequency selective electric field measurements will be presented. The system will be applicable to field measurement problems up to frequencies in the microwave regime. Additionally, it will provide minimum interference with the measured field, due to the optical fiber coupled sensor head. The electrooptic key components within the head of this sensor system are an array of photovoltaic cells and an electroabsorption waveguide modulator. Based on experimental results these components will be discussed and evaluated for the application within the sensor system. Furthermore, a novel fiber modulator coupling technique employing the monolithic integration of the device with InP V-grooves will be presented.

  11. Ultra-Trace Chemical Sensing with Long-Wave Infrared Cavity-Enhanced Spectroscopic Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Taubman, Matthew S.; Myers, Tanya L.; Cannon, Bret D.; Williams, Richard M.; Schultz, John F.

    2003-02-20

    The infrared sensors task of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project (Task B of Project PL211) is focused on the science and technology of remote and in-situ spectroscopic chemical sensors for detecting proliferation and coun-tering terrorism. Missions to be addressed by remote chemical sensor development in-clude detecting proliferation of nuclear or chemical weapons, and providing warning of terrorist use of chemical weapons. Missions to be addressed by in-situ chemical sensor development include countering terrorism by screening luggage, personnel, and shipping containers for explosives, firearms, narcotics, chemical weapons, or chemical weapons residues, and mapping contaminated areas. The science and technology is also relevant to chemical weapons defense, air operations support, monitoring emissions from chemi-cal weapons destruction or industrial activities, law enforcement, medical diagnostics, and other applications. Sensors for most of these missions will require extreme chemical sensitivity and selectiv-ity because the signature chemicals of importance are expected to be present in low con-centrations or have low vapor pressures, and the ambient air is likely to contain pollutants or other chemicals with interfering spectra. Cavity-enhanced chemical sensors (CES) that draw air samples into optical cavities for laser-based interrogation of their chemical content promise real-time, in-situ chemical detection with extreme sensitivity to specified target molecules and superb immunity to spectral interference and other sources of noise. PNNL is developing CES based on quantum cascade (QC) lasers that operate in the mid-wave infrared (MWIR - 3 to 5 microns) and long-wave infrared (LWIR - 8 to 14 mi-crons), and CES based on telecommunications lasers operating in the short-wave infrared (SWIR - 1 to 2 microns). All three spectral regions are promising because smaller mo-lecular absorption cross sections in the SWIR

  12. Rugged Optical Atmospheric Humidity Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Trace species measurement on unmanned atmospheric research craft suitable for interplanetary travel is a demanding application for optical sensing techniques. Yet...

  13. Optical fiber sensors for IoT and smart devices

    CERN Document Server

    Domingues, Maria de Fátima F

    2017-01-01

    This brief provides a review of the evolution of optical fiber sensing solutions and related applications. Unique production methods are presented and discussed, highlighting their evolution and analyzing their complexity. Under this scope, this brief presents the existing silica optical fiber sensors and polymer optical fiber sensors solutions, comparing its field of action (sensitivity, accuracy), complexity of manufacture and economic cost. Special attention is given to low-cost production methods. This brief evaluates the different existing techniques, assessing the accuracy and suitability of these sensors for possible Internet of Things (IoT) integration in different considered scenarios. Critical analytical techniques, also covered in this brief, are expected to play a key role in the world of IoT and the smart city of tomorrow.

  14. Damage monitoring and impact detection using optical fiber vibration sensors

    Science.gov (United States)

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

    2002-06-01

    Intensity-based optical fiber vibrations sensors (OFVSs) are used in damage monitoring of fiber-reinforced plastics, in vibration sensing, and location of impacts. OFVSs were constructed by placing two cleaved fiber ends in a capillary tube. This sensor is able to monitor structural vibrations. For vibration sensing, the optical fiber sensor was mounted on the carbon fiber reinforced composite beam, and its response was investigated for free and forced vibration. For locating impact points, four OFVSs were placed at chosen positions and the different arrival times of impact-generated vibration signals were recorded. The impact location can be determined from these time delays. Indentation and tensile tests were performed with the measurement of the optical signal and acoustic emission (AE). The OFVSs accurately detected both free and forced vibration signals. Accurate locations of impact were determined on an acrylate plate. It was found that damage information, comparable in quality to AE data, could be obtained from the OFVS signals.

  15. Smart optical distance sensor for automatic welding detection

    Science.gov (United States)

    Kahl, Michael; Rinner, Stefan; Ettemeyer, Andreas

    2015-05-01

    In this paper, we describe a simple and cost-effective method and measuring device for automatic detection of welding. The sensor is to be used in automatic darkening filters (ADF) of welding helmets protecting the operator from intensive hazardous UV radiation. For reasons discussed in detail below, conventional sensor principles used in ADF are being out-dated. Here, we critically revise some alternatives and propose an approach comprising an optical distance sensor. Its underlying principle is triangulation with two pin-hole cameras. The absence of optical components such as lenses results in very low cost. At first, feasibility is tested with optical simulations. Additionally, we present measurement results that prove the practicability of our proposal.

  16. Carbon laminates with RE doped optical fibre sensors

    Science.gov (United States)

    Miluski, Piotr; Kochanowicz, Marcin; Żmojda, Jacek; Silva, AbíLio P.; Reis, Paulo N. B.; Dorosz, Dominik

    2016-11-01

    A new type of luminescent optical fibre sensor for structural health monitoring of composite laminates (CFRP) is proposed. The Nd3+ doped multi-core doubleclad fibre incorporated in composite structure was used as a distributed temperature sensor. The change of luminescence intensity (Nd3+ ions) at the wavelength of 880 nm (4F3/2 → 4I9/2) and 1060 nm (4F3/2 → 4I11/2) was used for internal temperature monitoring. The special construction of optical fibre was used as it assures an efficient pumping mechanism and, at same time, it increases the measuring sensitivity. The linear response with relative sensitivity 0.015 K-1 was obtained for temperature range from 30 up to 75ºC. The manufacturing process of CFRP with embedded optical fibre sensor is also discussed.

  17. Chemical sensor network for pH monitoring

    Directory of Open Access Journals (Sweden)

    Claudia Manjarrés

    2016-02-01

    Full Text Available Monitoring of water sources is a major concern worldwide. Wireless sensor networks (WSN may be used for this monitoring. However, current systems employ mainly physical sensors for variables such as temperature, pressure, humidity and light. Wireless chemical sensors networks (WCSNs for environmental monitoring are scarce due to the lack of autonomy of conventional sensors. This paper presents results of a WCSN for monitoring pH based on ion selective field effect transistors (ISFETs. Sensing nodes employ a human interface required for in situ calibration of chemical sensors. Unlike most studies, our work evaluates the network employing chemical measurements and wireless network metrics. Results show zero packet losses by using a time division multiple access (TDMA protocol. The network allows wireless communication within 300 m including attenuation from buildings and trees. Therefore, the system presented in this paper is suitable for long range applications with unobstructed line of sight. pH measurements present a standard deviation below 1%, showing high repeatability. When compared to a commercial pH meter, difference in measurements is below 5%. As a consequence, accuracy is adequate for the application. Measurements also presented high stability during 3 h of continuous measurement.

  18. Fiber Optic Temperature Sensor Based on Multimode Interference Effects

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Soto, J G; Antonio-Lopez, J E; Sanchez-Mondragon, J J [Photonics and Optical Physics Laboratory, Optics Department, INAOE Apdo. Postal 51 and 216, Tonantzintla, Puebla 72000 (Mexico); May-Arrioja, D A, E-mail: darrioja@uat.edu.mx

    2011-01-01

    A novel fiber optic temperature sensor based on multimode interference was designed, fabricated and tested. The sensor is very simple and inexpensive since we only need to splice a section of multimode fiber between two single mode fibers. Using this device a sensing range of 25 deg. C to 375 deg. C is demonstrated. We should also highlight that due to the pass-band filter response of MMI devices, multiplexing is rather simple by just changing the length of the multimode section.

  19. Optical Sensors and Methods for Underwater 3D Reconstruction

    Directory of Open Access Journals (Sweden)

    Miquel Massot-Campos

    2015-12-01

    Full Text Available This paper presents a survey on optical sensors and methods for 3D reconstruction in underwater environments. The techniques to obtain range data have been listed and explained, together with the different sensor hardware that makes them possible. The literature has been reviewed, and a classification has been proposed for the existing solutions. New developments, commercial solutions and previous reviews in this topic have also been gathered and considered.

  20. Optical fiber sensor for membrane submicrometer vibration measurement.

    Science.gov (United States)

    Prokopczuk, Krzysztof; Rozwadowski, Krzysztof; Aleksandra Starzyńska, M D; Domański, Andrzej W

    2014-09-10

    This paper presents an optical fiber sensor for membrane submicrometer vibration measurement. The sensor is designed ultimately for low-cost medical audiometric applications such as determining the mobility of the tympanic membrane stimulated by the tone. The sensing method is minimally invasive, and the sensing head does not contact the surface of the membrane. Measurements were performed on tympanic membrane phantoms. Deflections of a few nanometers were measured, and vibration maps of phantoms were taken.

  1. Review of fiber-optic pressure sensors for biomedical and biomechanical applications

    Science.gov (United States)

    Roriz, Paulo; Frazão, Orlando; Lobo-Ribeiro, António B.; Santos, José L.; Simões, José A.

    2013-05-01

    As optical fibers revolutionize the way data is carried in telecommunications, the same is happening in the world of sensing. Fiber-optic sensors (FOS) rely on the principle of changing the properties of light that propagate in the fiber due to the effect of a specific physical or chemical parameter. We demonstrate the potentialities of this sensing concept to assess pressure in biomedical and biomechanical applications. FOSs are introduced after an overview of conventional sensors that are being used in the field. Pointing out their limitations, particularly as minimally invasive sensors, is also the starting point to argue FOSs are an alternative or a substitution technology. Even so, this technology will be more or less effective depending on the efforts to present more affordable turnkey solutions and peer-reviewed papers reporting in vivo experiments and clinical trials.

  2. Optic Fiber-Based Dynamic Pressure Sensor

    Institute of Scientific and Technical Information of China (English)

    Jiu-Lin Gan; Hai-Wen Cai; Jian-Xin Geng; Zheng-Qing Pan; Rong-Hui Qu; Zu-Jie Fang

    2008-01-01

    Weigh-in-Motion(WIM) technique is the process of measuring the dynamic tire forces of a moving vehicle and estimating the corresponding tire loads of the static vehicle. Compared with the static weigh station, WIM station is an efficient and cost effective choice that will minimize unneccessary stops and delay for truckers. The way to turn birefringence of single-mode fiber into a prime quality for a powerful and reliable sensor is shown. Preliminary results for the development of a weigh-in-motion (WIM) technique based on sagnac-loop sensor are presented. After a brief description of the sensor and its principle of operation, the theoretical model is developed. Then, a full characterization made in static conditions is presented.

  3. EMBEDDED OPTICAL SENSORS FOR THERMAL BARRIER COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    David R. Clarke

    2004-12-16

    In this first year of the program we have focused on the selection of rare-earth dopants for luminescent sensing in thermal barrier coating materials, the effect of dopant concentration on several of the luminescence characteristics and initial fabrication of one type of embedded sensor, the ''red-line'' sensor. We have initially focused on erbium as the lanthanide dopant for luminescence doping of yttria-stabilized zirconia and europium as the lanthanide for luminescence doping of gadolinium zirconate. The latter exhibits a temperature-dependent luminescence lifetime up to at least 1100 C. A buried layer, ''red-line'' sensor in an electron-beam deposited yttria-stabilized zirconia coating with erbium has been demonstrated and exhibits a temperature-dependent luminescence lifetime up to at least 400 C.

  4. MEMS device for mass market gas and chemical sensors

    Science.gov (United States)

    Kinkade, Brian R.; Daly, James T.; Johnson, Edward A.

    2000-08-01

    Gas and chemical sensors are used in many applications. Industrial health and safety monitors allow companies to meet OSHA requirements by detecting harmful levels of toxic or combustible gases. Vehicle emissions are tested during annual inspections. Blood alcohol breathalizers are used by law enforcement. Refrigerant leak detection ensures that the Earth's ozone layer is not being compromised. Industrial combustion emissions are also monitored to minimize pollution. Heating and ventilation systems watch for high levels of carbon dioxide (CO2) to trigger an increase in fresh air exchange. Carbon monoxide detectors are used in homes to prevent poisoning from poor combustion ventilation. Anesthesia gases are monitored during a patients operation. The current economic reality is that two groups of gas sensor technologies are competing in two distinct existing market segments - affordable (less reliable) chemical reaction sensors for consumer markets and reliable (expensive) infrared (IR) spectroscopic sensors for industrial, laboratory, and medical instrumentation markets. Presently high volume mass-market applications are limited to CO detectros and on-board automotive emissions sensors. Due to reliability problems with electrochemical sensor-based CO detectors there is a hesitancy to apply these sensors in other high volume applications. Applications such as: natural gas leak detection, non-invasive blood glucose monitoring, home indoor air quality, personal/portable air quality monitors, home fire/burnt cooking detector, and home food spoilage detectors need a sensor that is a small, efficient, accurate, sensitive, reliable, and inexpensive. Connecting an array of these next generation gas sensors to wireless networks that are starting to proliferate today creates many other applications. Asthmatics could preview the air quality of their destinations as they venture out into the day. HVAC systems could determine if fresh air intake was actually better than the air

  5. Design Of Piezoelectric Microcantilever Chemical Sensors In COMSOL Multiphysics Area

    Directory of Open Access Journals (Sweden)

    Maziar Norouzi

    2009-05-01

    Full Text Available This paper offers an analytical modeling ofthin-filmed, multi-layer piezoelectric microcantileversthat are used as MEMS sensors. These sensors arechemical kind and use piezoelectric microcantilever.These types of microcantilevers are covered withvariety of unique probe coating. The sensor has highsensitivity with external voltage measured in mV anduses PSD1 system to indentify chemical ingredients ofmaterials. The identification of the chemical ingredientof materials is based on change in angle of microcantilever in the liquid or gas environment. Thedeflection of microcantilever results in varying voltagethat can be used to analyze materials. Analyticalsimulation using Cosmol software and theoreticalcomputations using equations will be offered in orderto determine the parameters for optimal design setting.The analytical simulation includes design of mems andCosmol software model development. The analyticalmodel of the cantilever will be analyzed and theprocess of its construction will be discussed.

  6. New multiplexing structures for fiber optic sensors

    OpenAIRE

    Leandro González, Daniel

    2017-01-01

    El campo de la fibra óptica ha sufrido una rápida evolución durante las últimas décadas debido a sus buenas prestaciones en aplicaciones de telecomunicaciones. Aprovechando este avance científico y técnico en componentes fotónicos, los sensores de fibra óptica han emergido como una solución flexible para solventar algunas de las principales limitaciones sufridas por los sensores convencionales. Por ejemplo, la fibra óptica es químicamente inerte y electromagnéticamente pasiva. ...

  7. Nonlinear optical field sensors in extreme electromagnetic and acoustic environments

    Science.gov (United States)

    Garzarella, Anthony; Wu, Dong Ho

    2014-03-01

    Sensors based on electro-optic (EO) and magneto-optic (MO) crystals measure external electric and magnetic fields through changes in birefringence which the fields induce on the nonlinear crystals. Due to their small size and all-dielectric structure, EO and MO sensors are ideal in environments involving very large electromagnetic powers. Conventional antennas and metallic probes not only present safety hazards, due to their metallic structure and the presence of large currents, but they can also perturb the very fields they intend to measure. In the case of railguns, the large electromagnetic signals are also accompanied by tremendous acoustic noise, which presents a noise background that the sensors must overcome. In this presentation, we describe extensive data obtained from fiber optic EO and MO sensors used in the railgun of the Naval Research Laboratory. Along with the field measurements obtained, we will describe the interactions between the acoustic noise and the nonlinear crystals (most notably, photoelastic effects), the noise equivalent fields they produce, and methods they could be suppressed through the optical and geometrical configurations of the sensor so that the signal to noise ratio can be maximized.

  8. Chemical Sensors Based on Molecularly Imprinted Sol-Gel Materials

    Directory of Open Access Journals (Sweden)

    Franz L. Dickert

    2010-03-01

    Full Text Available The sol-gel technique is earning the worldwide attention of researchers in the field of material science, due to its versatility in synthesizing inorganic ceramic materials at mild conditions. High purity, homogeneity, controlled porosity, stable temperature and nanoscale structuring are the most remarkable features offered by this method for generating highly sensitive and selective matrices to incorporate analyte molecules. The crafting of sol-gel sensors through molecular imprinting has put great influence on the development of innovative chemical sensors, which can be seen from the growing number of publications in this field. The review provides a brief overview of sol-gel sensor applications, and discusses the contribution of molecular imprinting in exploring the new world of sensors.

  9. Supramolecular Derivation of Graphene Nanomaterials for Chemical Sensors

    DEFF Research Database (Denmark)

    Olsen, Gunnar

    With properties such as high surface area, high conductivity, and low production cost with easy up-scaling, graphene-like materials provide a promising support for many applications, one of which is for chemical sensors. By functionalization with molecular receptors such as supramolecular moietie...

  10. Durable chemical sensors based on field-effect transistors

    NARCIS (Netherlands)

    Reinhoudt, D.N.

    1995-01-01

    The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a sodium-se

  11. Optical and Electronic NOx Sensors for Applications in Mechatronics

    Directory of Open Access Journals (Sweden)

    Scott D. Wolter

    2009-05-01

    Full Text Available Current production and emerging NOx sensors based on optical and nanomaterials technologies are reviewed. In view of their potential applications in mechatronics, we compared the performance of: i Quantum cascade lasers (QCL based photoacoustic (PA systems; ii gold nanoparticles as catalytically active materials in field-effect transistor (FET sensors, and iii functionalized III-V semiconductor based devices. QCL-based PA sensors for NOx show a detection limit in the sub part-per-million range and are characterized by high selectivity and compact set-up. Electrochemically synthesized gold-nanoparticle FET sensors are able to monitor NOx in a concentration range from 50 to 200 parts per million and are suitable for miniaturization. Porphyrin-functionalized III-V semiconductor materials can be used for the fabrication of a reliable NOx sensor platform characterized by high conductivity, corrosion resistance, and strong surface state coupling.

  12. Optical and Electronic NOx Sensors for Applications in Mechatronics

    Science.gov (United States)

    Di Franco, Cinzia; Elia, Angela; Spagnolo, Vincenzo; Scamarcio, Gaetano; Lugarà, Pietro Mario; Ieva, Eliana; Cioffi, Nicola; Torsi, Luisa; Bruno, Giovanni; Losurdo, Maria; Garcia, Michael A.; Wolter, Scott D.; Brown, April; Ricco, Mario

    2009-01-01

    Current production and emerging NOx sensors based on optical and nanomaterials technologies are reviewed. In view of their potential applications in mechatronics, we compared the performance of: i) Quantum cascade lasers (QCL) based photoacoustic (PA) systems; ii) gold nanoparticles as catalytically active materials in field-effect transistor (FET) sensors, and iii) functionalized III-V semiconductor based devices. QCL-based PA sensors for NOx show a detection limit in the sub part-per-million range and are characterized by high selectivity and compact set-up. Electrochemically synthesized gold-nanoparticle FET sensors are able to monitor NOx in a concentration range from 50 to 200 parts per million and are suitable for miniaturization. Porphyrin-functionalized III-V semiconductor materials can be used for the fabrication of a reliable NOx sensor platform characterized by high conductivity, corrosion resistance, and strong surface state coupling. PMID:22412315

  13. Two-interferometer fiber optic sensor with disturbance localization

    Science.gov (United States)

    Kondrat, M.; Szustakowski, M.; Ciurapinski, W.; Zyczkowski, M.

    2006-09-01

    We present investigation results of a new generation of the fiber optic perimeter sensor in a Sagnac and Michelson interferometers configuration. This sensor can detect a potential intruder and determine its position along a protected zone. We propose a localization method that makes use of the inherent properties of both interferometers. After demodulation of signals from both interferometers, the obtained amplitude characteristic of the Sagnac interferometer depends on position of a disturbance along the interferometer, while amplitude characteristic of the Michelson interferometer do not depend on this position. So, quotient of both demodulated characteristics makes it possible to localize the disturbance. Arrangement of a laboratory model of the sensor and its signal processing scheme is also presented. During research of the laboratory model of the sensor, it was possible to detect the position of the disturbance with resolution of about 40m along the 6-km long sensor.

  14. Optical fiber sensors fabricated by the focused ion beam technique

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Wang, Fei; Bang, Ole

    2012-01-01

    crystal fiber (PCF). Using this technique we fabricate a highly compact fiber-optic Fabry-Pérot (FP) refractive index sensor near the tip of fiber taper, and a highly sensitive in-line temperature sensor in PCF. We also demonstrate the potential of using FIB to selectively fill functional fluid......Focused ion beam (FIB) is a highly versatile technique which helps to enable next generation of lab-on-fiber sensor technologies. In this paper, we demonstrate the use application of FIB to precisely mill the fiber taper and end facet of both conventional single mode fiber (SMF) and photonic...

  15. Templated Chemically Deposited Semiconductor Optical Fiber Materials

    Science.gov (United States)

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

    2013-07-01

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

  16. TOPICAL REVIEW: Biological and chemical sensors for cancer diagnosis

    Science.gov (United States)

    Simon, Elfriede

    2010-11-01

    The great challenge for sensor systems to be accepted as a relevant diagnostic and therapeutic tool for cancer detection is the ability to determine the presence of relevant biomarkers or biomarker patterns comparably to or even better than the traditional analytical systems. Biosensor and chemical sensor technologies are already used for several clinical applications such as blood glucose or blood gas measurements. However, up to now not many sensors have been developed for cancer-related tests because only a few of the biomarkers have shown clinical relevance and the performance of the sensor systems is not always satisfactory. New genomic and proteomic tools are used to detect new molecular signatures and identify which combinations of biomarkers may detect best the presence or risk of cancer or monitor cancer therapies. These molecular signatures include genetic and epigenetic signatures, changes in gene expressions, protein biomarker profiles and other metabolite profile changes. They provide new changes in using different sensor technologies for cancer detection especially when complex biomarker patterns have to be analyzed. To address requirements for this complex analysis, there have been recent efforts to develop sensor arrays and new solutions (e.g. lab on a chip) in which sampling, preparation, high-throughput analysis and reporting are integrated. The ability of parallelization, miniaturization and the degree of automation are the focus of new developments and will be supported by nanotechnology approaches. This review recaps some scientific considerations about cancer diagnosis and cancer-related biomarkers, relevant biosensor and chemical sensor technologies, their application as cancer sensors and consideration about future challenges.

  17. Fiber optic micro sensor for the measurement of tendon forces

    Directory of Open Access Journals (Sweden)

    Behrmann Gregory P

    2012-10-01

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

  18. Fibre optic surface plasmon resonance sensor system designed for smartphones.

    Science.gov (United States)

    Bremer, Kort; Roth, Bernhard

    2015-06-29

    A fibre optic surface plasmon resonance (SPR) sensor system for smartphones is reported, for the first time. The sensor was fabricated by using an easy-to-implement silver coating technique and by polishing both ends of a 400 µm optical fibre to obtain 45° end-faces. For excitation and interrogation of the SPR sensor system the flash-light and camera at the back side of the smartphone were employed, respectively. Consequently, no external electrical components are required for the operation of the sensor system developed. In a first application example a refractive index sensor was realised. The performance of the SPR sensor system was demonstrated by using different volume concentrations of glycerol solution. A sensitivity of 5.96·10(-4) refractive index units (RIU)/pixel was obtained for a refractive index (RI) range from 1.33 to 1.36. In future implementations the reported sensor system could be integrated in a cover of a smartphone or used as a low-cost, portable point-of-care diagnostic platform. Consequently it offers the potential of monitoring a large variety of environmental or point-of-care parameters in combination with smartphones.

  19. WGM-Resonator/Tapered-Waveguide White-Light Sensor Optics

    Science.gov (United States)

    Stekalov, Dmitry; Maleki, Lute; Matsko, Andrey; Savchenkov, Anatoliy; Iltchenko, Vladimir

    2007-01-01

    Theoretical and experimental investigations have demonstrated the feasibility of compact white-light sensor optics consisting of unitary combinations of (1) low-profile whispering-gallery-mode (WGM) resonators and (2) tapered rod optical waveguides. These sensors are highly wavelength-dispersive and are expected to be especially useful in biochemical applications for measuring absorption spectra of liquids. These sensor optics exploit the properties of a special class of non-diffracting light beams that are denoted Bessel beams because their amplitudes are proportional to Bessel functions of the radii from their central axes. High-order Bessel beams can have large values of angular momentum. In a sensor optic of this type, a low-profile WGM resonator that supports modes having large angular momenta is used to generate high-order Bessel beams. As used here, "low-profile" signifies that the WGM resonator is an integral part of the rod optical waveguide but has a radius slightly different from that of the adjacent part(s).

  20. Acoustic emission monitoring using a multimode optical fiber sensor

    Science.gov (United States)

    Vandenplas, Steve; Papy, Jean-Michel; Wevers, Martine; Van Huffel, Sabine

    2004-07-01

    Permanent damage in various materials and constructions often causes high-energy high-frequency acoustic waves. To detect those so called `acoustic emission (AE) events', in most cases ultrasonic transducers are embedded in the structure or attached to its surface. However, for many applications where event localization is less important, an embedded low-cost multimode optical fiber sensor configured for event counting may be a better alternative due to its corrosion resistance, immunity to electromagnetic interference and light-weight. The sensing part of this intensity-modulated sensor consists of a multimode optical fiber. The sensing principle now relies on refractive index variations, microbending and mode-mode interferences by the action of the acoustic pressure wave. A photodiode is used to monitor the intensity of the optical signal and transient signal detection techniques (filtering, frame-to-frame analysis, recursive noise estimation, power detector estimator) on the photodiode output are applied to detect the events. In this work, the acoustic emission monitoring capabilities of the multimode optical fiber sensor are demonstrated with the fiber sensor embedded in the liner of a Power Data Transmission (PDT) coil to detect damage (delamination, matrix cracking and fiber breaking) while bending the coil. With the Hankel Total Least Square (HTLS) technique, it is shown that both the acoustic emission signal and optical signal can be modeled with a sum of exponentially damped complex sinusoids with common poles.

  1. Recent Developments in Micro-Structured Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    Yanping Xu

    2017-01-01

    Full Text Available Recent developments in fiber-optic sensing have involved booming research in the design and manufacturing of novel micro-structured optical fiber devices. From the conventional tapered fiber architectures to the novel micro-machined devices by advanced laser systems, thousands of micro-structured fiber-optic sensors have been proposed and fabricated for applications in measuring temperature, strain, refractive index (RI, electric current, displacement, bending, acceleration, force, rotation, acoustic, and magnetic field. The renowned and unparalleled merits of sensors-based micro-machined optical fibers including small footprint, light weight, immunity to electromagnetic interferences, durability to harsh environment, capability of remote control, and flexibility of directly embedding into the structured system have placed them in highly demand for practical use in diverse industries. With the rapid advancement in micro-technology, micro-structured fiber sensors have benefitted from the trends of possessing high performance, versatilities and spatial miniaturization. Here, we comprehensively review the recent progress in the micro-structured fiber-optic sensors with a variety of architectures regarding their fabrications, waveguide properties and sensing applications.

  2. Towards biochips using microstructured optical fiber sensors

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Hoiby, Poul Erik; Jensen, Jesper Bo

    2006-01-01

    In this paper we present the first incorporation of a microstructured optical fiber (MOF) into biochip applications. A 16-mm-long piece of MOF is incorporated into an optic-fluidic coupler chip, which is fabricated in PMMA polymer using a CO2 laser. The developed chip configuration allows...... the continuous control of liquid flow through the MOF and simultaneous optical characterization. While integrated in the chip, the MOF is functionalized towards the capture of a specific single-stranded DNA string by immobilizing a sensing layer on the microstructured internal surfaces of the fiber. The sensing...

  3. Optical fiber sensors for damage analysis in aerospace materials

    Science.gov (United States)

    Schindler, Paul; May, Russell; Claus, Richard

    1995-01-01

    Under this grant, fiber optic sensors were investigated for use in the nondestructive evaluation of aging aircraft. Specifically, optical fiber sensors for detection and location of impacts on a surface, and for detection of corrosion in metals were developed. The use of neural networks was investigated for determining impact location by processing the output of a network of fiberoptic strain sensors distributed on a surface. This approach employs triangulation to determine location by comparing the arrival times at several sensors, of the acoustic signal generated by the impact. For this study, a neural network simulator running on a personal computer was used to train a network using a back-propagation algorithm. Fiber optic extrinsic Fabry-Perot interferometer (EFPI) strain sensors are attached to or embedded in the surface, so that stress waves emanating from an impact can be detected. The ability of the network to determine impact location by time-or-arrival of acoustic signals was assessed by comparing network outputs with actual experimental results using impacts on a panel instrumented with optical fiber sensors. Using the neural network to process the sensor outputs, the impact location can be inferred to centimeter range accuracy directly from the arrival time data. In addition, the network can be trained to determine impact location, regardless of material anisotropy. Results demonstrate that a back-propagation network identifies impact location for an anisotropic graphite/bismaleimide plate with the same accuracy as that for an isotropic aluminum plate. Two different approaches were investigated for the development of fiber optic sensors for corrosion detection in metals, both utilizing optical fiber sensors with metal coatings. In the first approach, an extrinsic Fabry-Perot interferometric fiber optic strain sensor was placed under tensile stress, and while in the resulting strained position, a thick coating of metal was applied. Due to an increase in

  4. Polydimethylsiloxane fibers for optical fiber sensor of displacement

    Science.gov (United States)

    Martincek, Ivan; Pudis, Dusan; Gaso, Peter

    2013-09-01

    The paper describes the preparation of polydimethylsiloxane (PDMS) fiber integrated on the conventional optical fibers and their use for optical fiber displacement sensor. PDMS fiber was made of silicone elastomer Sylgard 184 (Dow Corning) by drawing from partially cured silicone. Optical fiber displacement sensor using PDMS fiber is based on the measurement of the local minimum of optical signal in visible spectral range generated by intermodal interference of circularly symmetric modes. Position of the local minimum in spectral range varies by stretching the PDMS fiber of 230 μm in the wavelength range from 688 to 477 nm. In the stretched PDMS fiber is possible to determine the longitudinal displacement with an accuracy of approximately 1 micrometer.

  5. Sensitization of an optical fiber methane sensor with graphene

    Science.gov (United States)

    Zhang, J. Y.; Ding, E. J.; Xu, S. C.; Li, Z. H.; Wang, X. X.; Song, F.

    2017-09-01

    We analyze the mechanism by which tin oxide can be utilized for the optical sensing of methane gas via surface adsorption and electromagnetic theory. Single-mode optical fibers with core diameters of 9 μm and cladding diameters of 12 μm were used. A 15 mm-long segment of each optical fiber was polished to the core via wheel side-polishing; the exposed fiber core areas were coated with graphene-doped tin oxide such that a novel graphene-based optical fiber methane sensor was fabricated. The experimental results show that the sensor exhibits excellent linear fitting and reproducibility, making it useful for the detection of low concentrations of methane.

  6. Fiber Optic Sensor Components and Systems for Smart Materials and Structures

    Science.gov (United States)

    Lyons, R.

    1999-01-01

    The general objective of the funded research effort has been the development of discrete and distributed fiber sensors and fiber optic centered opto-electronic networks for the intelligent monitoring of phenomena in various aerospace structures related to NASA Marshall specific applications. In particular, we have proposed and have been developing technologies that we believe to be readily transferrable and which involve new fabrication techniques. The associated sensors developed can be incorporated into the matrix or on the surfaces of structures for the purpose of sensing stress, strain, temperature-both low and high, pressure field variations, phase changes, and the presence of various chemical constituents.

  7. Miniature dissolved oxygen and turbulence optical sensor for river and coastal environmental applications

    Science.gov (United States)

    Carapezza, Edward M.; Lombardi, Gabrial; Butman, Jerry; Babb, Ivar

    2009-09-01

    This paper describes an innovative miniature optical sensor for predicting dissolved oxygen concentrations and measuring turbulence in river and littoral water columns. The dissolved oxygen and turbulence sensor consists of a single-frequency laser transmitter and a photodetector on which the scattered light from the turbulent water at the base of a dam or spillway is coherently mixed with a sample of the transmitted beam. This miniature sensor could be used both upstream and downsteam of dams and weirs to predict the amount of dissolved oxygen and turbulence in these waters. It could also be used on mobile platforms, such as unmanned underwater vehicles (UUV's), to monitor the edges of biological or chemical plumes or for wake follow platforms, schools of fish or marine mammals or on stationary unattended underwater sensors to monitor natural aeration and turbulence in littoral and riverine waters. Arrays of fixed unattended sensors could be used to detect the wake of transiting submerged vehicles, scuba divers, marine mammals or large schools of fish. A mobile platform equipped with a miniature sensor could to be cued to the general location and depth of an underwater target and then the platform could use this small aperture sensor to acquire and follow the wake. This dissolved oxygen and turbulence sensor system could be miniaturized and packaged into a very small volume; approximately the size of a wristwatch.

  8. Odour Detection Methods: Olfactometry and Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Sara Lovascio

    2011-05-01

    Full Text Available The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc. and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality; this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective “analytical instrument” for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses are then described, focusing on their better performances for environmental analysis. Odour emission monitoring

  9. Mathematical Model of Fiber Optic Temperature Sensor Based on Optic Absorption and Experiment Testing

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.

  10. Embedding of fibre optic sensors within flexible host

    OpenAIRE

    Ferraris, Eleonora; Van Gijseghem, Tim; Yan, Chunxiao; Van Hoe, Bram; Van Steenberge, Geert; Van Daele, Peter; Dubruel, Peter; Reynaerts, Dominiek

    2009-01-01

    This work deals with the establishment of a UV polymerisation procedure combined with moulding technology towards the development of a mass production technology for the fabrication of flexible polymers with optical fibres embedded. The concept is to provide an artificial sensing skin based on fibre optic sensors which can be applied to irregular or moveable surfaces for distributed pressure applications, as for instance in structural monitoring or rehabilitation. The selected polymers for su...

  11. Detection of trace elements in DI water and comparison of several water solutions by using EF-FLRD chemical sensors

    Science.gov (United States)

    Kaya, M.; Wang, C.

    2017-02-01

    Detection of trace elements in DI water and comparison of several types of water respons such as DI water, tap water, and ocean water were studied by using EF-FLRD chemical sensors. Solutions of Mg, Fe, P, and Cd elements with a concentration of 1000 µg/ml (1 mg/ml) which corresponds to 1000 ppm by weight were tested. DI water, tap water, and real ocean water were utilized as medium to observe refractive index difference of solutions. The EF sensing technique which is based on the EF scattering effect was employed for the detection of trace chemicals and recording of solution responses. Due to the refractive index differences between solutions, optical loss of the sensor was different when the sensor head was immersed into solutions of approximately 10 ml each. The differences of the refractive indices are presented by recording ringdown times when the sensor head was immersed into the solutions. Fast response (˜1s), high sensitive, and reproducible EF-FLRD chemical sensors were fabricated and tested in laboratory conditions. High sensitivity of the sensors due to being capability of detecting smaller differences between measurands without any additional components or treatment makes the EF-FLRD sensors more attractive. Enhanced sensitivity of the EF-FLRD chemical sensors as a result of the multi-pass nature of the FLRD technique has potential application in detecting of trace elements in monitoring of water quality.

  12. Carbon Nanotube Based Chemical Sensors for Space and Terrestrial Applications

    Science.gov (United States)

    Li, Jing; Lu, Yijiang

    2009-01-01

    A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs), on a pair of interdigitated electrodes (IDE) processed with a silicon-based microfabrication and micromachining technique. The IDE fingers were fabricated using photolithography and thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to nitrogen dioxide, acetone, benzene, nitrotoluene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing of carbon nanotubes in our sensor platform can be understood by intra- and inter-tube electron modulation in terms of charge transfer mechanisms. As a result of the charge transfer, the conductance of p-type or hole-richer SWNTs in air will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost. Additionally, a wireless capability of such a sensor chip can be used for networked mobile and fixed-site detection and warning systems for military bases, facilities and battlefield areas.

  13. Data Optical Networking Architecture Using Wavelength-Division Multiplexing Method for Optical Sensors

    Science.gov (United States)

    Nguyen, Hung D.

    2008-01-01

    Recently there has been a growth in the number of fiber optical sensors used for health monitoring in the hostile environment of commercial aircraft. Health monitoring to detect the onset of failure in structural systems from such causes as corrosion, stress corrosion cracking, and fatigue is a critical factor in safety as well in aircraft maintenance costs. This report presents an assessment of an analysis model of optical data networking architectures used for monitoring data signals among these optical sensors. Our model is focused on the design concept of the wavelength-division multiplexing (WDM) method since most of the optical sensors deployed in the aircraft for health monitoring typically operate in a wide spectrum of optical wavelengths from 710 to 1550 nm.

  14. Microfabricated Chemical Sensors for Aerospace Fire Detection Applications

    Science.gov (United States)

    Hunter, Gary W.; Neudeck, Philip G.; Fralick, Gustave; Thomas, Valarie; Makel, D.; Liu, C. C.; Ward, B.; Wu, Q. H.

    2001-01-01

    The detection of fires on-board commercial aircraft is extremely important for safety reasons. Although dependable fire detection equipment presently exists within the cabin, detection of fire within the cargo hold has been less reliable and susceptible to false alarms. A second, independent method of fire detection to complement the conventional smoke detection techniques, such as the measurement of chemical species indicative of a fire, will help reduce false alarms and improve aircraft safety. Although many chemical species are indicative of a fire, two species of particular interest are CO and CO2. This paper discusses microfabricated chemical sensor development tailored to meet the needs of fire safety applications. This development is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. The individual sensor being developed and their level of maturity will be presented.

  15. Wavefront sensors for adaptive optical systems

    Science.gov (United States)

    Lukin, V. P.; Botygina, N. N.; Emaleev, O. N.; Konyaev, P. A.

    2010-10-01

    A high precision Shack-Hartmann wavefront (WF) sensor has been developed on the basis of a low-aperture off-axis diffraction lens array. The device is capable of measuring WF slopes at array sub-apertures of size 640x640 μm with an error not exceeding 4.80 arcsec (0.15 pixel), which corresponds to the standard deviation equal to 0.017λ at the reconstructed WF with wavelength λ . Also the modification of this sensor for adaptive system of solar telescope using extended scenes as tracking objects, such as sunspot, pores, solar granulation and limb, is presented. The software package developed for the proposed WF sensors includes three algorithms of local WF slopes estimation (modified centroids, normalized cross-correlation and fast Fourier-demodulation), as well as three methods of WF reconstruction (modal Zernike polynomials expansion, deformable mirror response functions expansion and phase unwrapping), that can be selected during operation with accordance to the application.

  16. Recent Improvement of Medical Optical Fibre Pressure and Temperature Sensors

    Directory of Open Access Journals (Sweden)

    Sven Poeggel

    2015-07-01

    Full Text Available This investigation describes a detailed analysis of the fabrication and testing of optical fibre pressure and temperature sensors (OFPTS. The optical sensor of this research is based on an extrinsic Fabry–Perot interferometer (EFPI with integrated fibre Bragg grating (FBG for simultaneous pressure and temperature measurements. The sensor is fabricated exclusively in glass and with a small diameter of 0.2 mm, making it suitable for volume-restricted bio-medical applications. Diaphragm shrinking techniques based on polishing, hydrofluoric (HF acid and femtosecond (FS laser micro-machining are described and analysed. The presented sensors were examined carefully and demonstrated a pressure sensitivity in the range of \\(s_p\\ = 2–10 \\(\\frac{\\text{nm}}{\\text{kPa}}\\ and a resolution of better than \\(\\Delta P\\ = 10 Pa protect (0.1 cm H\\(_2\\O. A static pressure test in 38 cmH\\(_2\\O shows no drift of the sensor in a six-day period. Additionally, a dynamic pressure analysis demonstrated that the OFPTS never exceeded a drift of more than 130 Pa (1.3 cm H\\(_2\\O in a 12-h measurement, carried out in a cardiovascular simulator. The temperature sensitivity is given by \\(k=10.7\\ \\(\\frac{\\text{pm}}{\\text{K}}\\, which results in a temperature resolution of better than \\(\\Delta T\\ = 0.1 K. Since the temperature sensing element is placed close to the pressure sensing element, the pressure sensor is insensitive to temperature changes.

  17. A New, Adaptable, Optical High-Resolution 3-Axis Sensor

    Directory of Open Access Journals (Sweden)

    Niels Buchhold

    2017-01-01

    Full Text Available This article presents a new optical, multi-functional, high-resolution 3-axis sensor which serves to navigate and can, for example, replace standard joysticks in medical devices such as electric wheelchairs, surgical robots or medical diagnosis devices. A light source, e.g., a laser diode, is affixed to a movable axis and projects a random geometric shape on an image sensor (CMOS or CCD. The downstream microcontroller’s software identifies the geometric shape’s center, distortion and size, and then calculates x, y, and z coordinates, which can be processed in attached devices. Depending on the image sensor in use (e.g., 6.41 megapixels, the 3-axis sensor features a resolution of 1544 digits from right to left and 1038 digits up and down. Through interpolation, these values rise by a factor of 100. A unique feature is the exact reproducibility (deflection to coordinates and its precise ability to return to its neutral position. Moreover, optical signal processing provides a high level of protection against electromagnetic and radio frequency interference. The sensor is adaptive and adjustable to fit a user’s range of motion (stroke and force. This recommendation aims to optimize sensor systems such as joysticks in medical devices in terms of safety, ease of use, and adaptability.

  18. A New, Adaptable, Optical High-Resolution 3-Axis Sensor.

    Science.gov (United States)

    Buchhold, Niels; Baumgartner, Christian

    2017-01-27

    This article presents a new optical, multi-functional, high-resolution 3-axis sensor which serves to navigate and can, for example, replace standard joysticks in medical devices such as electric wheelchairs, surgical robots or medical diagnosis devices. A light source, e.g., a laser diode, is affixed to a movable axis and projects a random geometric shape on an image sensor (CMOS or CCD). The downstream microcontroller's software identifies the geometric shape's center, distortion and size, and then calculates x, y, and z coordinates, which can be processed in attached devices. Depending on the image sensor in use (e.g., 6.41 megapixels), the 3-axis sensor features a resolution of 1544 digits from right to left and 1038 digits up and down. Through interpolation, these values rise by a factor of 100. A unique feature is the exact reproducibility (deflection to coordinates) and its precise ability to return to its neutral position. Moreover, optical signal processing provides a high level of protection against electromagnetic and radio frequency interference. The sensor is adaptive and adjustable to fit a user's range of motion (stroke and force). This recommendation aims to optimize sensor systems such as joysticks in medical devices in terms of safety, ease of use, and adaptability.

  19. A New, Adaptable, Optical High-Resolution 3-Axis Sensor

    Science.gov (United States)

    Buchhold, Niels; Baumgartner, Christian

    2017-01-01

    This article presents a new optical, multi-functional, high-resolution 3-axis sensor which serves to navigate and can, for example, replace standard joysticks in medical devices such as electric wheelchairs, surgical robots or medical diagnosis devices. A light source, e.g., a laser diode, is affixed to a movable axis and projects a random geometric shape on an image sensor (CMOS or CCD). The downstream microcontroller’s software identifies the geometric shape’s center, distortion and size, and then calculates x, y, and z coordinates, which can be processed in attached devices. Depending on the image sensor in use (e.g., 6.41 megapixels), the 3-axis sensor features a resolution of 1544 digits from right to left and 1038 digits up and down. Through interpolation, these values rise by a factor of 100. A unique feature is the exact reproducibility (deflection to coordinates) and its precise ability to return to its neutral position. Moreover, optical signal processing provides a high level of protection against electromagnetic and radio frequency interference. The sensor is adaptive and adjustable to fit a user’s range of motion (stroke and force). This recommendation aims to optimize sensor systems such as joysticks in medical devices in terms of safety, ease of use, and adaptability. PMID:28134824

  20. Lightning Current Measurement with Fiber-Optic Sensor

    Science.gov (United States)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George N.; Mata, Carlos T.; Mata, Angel G.; Snyder, Gary P.

    2014-01-01

    A fiber-optic current sensor is successfully developed with many potential applications for electric current measurement. Originally developed for in-flight lightning measurement, the sensor utilizes Faraday Effect in an optical fiber. The Faraday Effect causes linear light polarization in a fiber to rotate when the fiber is exposed to a magnetic field. The polarization change is detected using a reflective polarimetric scheme. Forming fiber loops and applying Ampere's law, measuring the total light rotation results in the determination of the total current enclosed. The sensor is conformable to complex structure geometry. It is also non-conductive and immune to electromagnetic interference, saturation or hysteresis. Installation is non-intrusive, and the sensor can be safely routed through flammable areas. Two similar sensor systems are described in this paper. The first system operates at 1310nm laser wavelength and is capable of measuring approximately 300 A - 300 kA, a 60 dB range. Laboratory validation results of aircraft lighting direct and in-direct effect current amplitudes are reported for this sensor. The second system operates at 1550nm wavelength and can measure about 400 A - 400 kA. Triggered-lightning measurement data are presented for this system. Good results are achieved in all cases.

  1. Relative-Motion Sensors and Actuators for Two Optical Tables

    Science.gov (United States)

    Gursel, Yekta; McKenney, Elizabeth

    2004-01-01

    Optoelectronic sensors and magnetic actuators have been developed as parts of a system for controlling the relative position and attitude of two massive optical tables that float on separate standard air suspensions that attenuate ground vibrations. In the specific application for which these sensors and actuators were developed, one of the optical tables holds an optical system that mimics distant stars, while the other optical table holds a test article that simulates a spaceborne stellar interferometer that would be used to observe the stars. The control system is designed to suppress relative motion of the tables or, on demand, to impose controlled relative motion between the tables. The control system includes a sensor system that detects relative motion of the tables in six independent degrees of freedom and a drive system that can apply force to the star-simulator table in the six degrees of freedom. The sensor system includes (1) a set of laser heterodyne gauges and (2) a set of four diode lasers on the star-simulator table, each aimed at one of four quadrant photodiodes at nominal corresponding positions on the test-article table. The heterodyne gauges are used to measure relative displacements along the x axis.

  2. YBCO Coated Conductor with an Integrated Optical Fiber Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Sathyamurthy, Srivatsan [American Superconductor Corporation, Devens, MA (United States); Rupich, Marty [American Superconductor Corporation, Devens, MA (United States); Schwartz, Justin [North Carolina State Univ., Raleigh, NC (United States)

    2016-03-31

    The primary objectives of the Phase I Project was to develop a proof-of-principle for a concept of integrating an optical fiber sensor into the laminated 2G wire, there by producing a functionalized 2G wire with self-monitoring capabilities

  3. Optical fibre temperature sensor in the cryogenic range

    NARCIS (Netherlands)

    Bertrand, S.; Jalocha, A.; Tribillon, G.; Bouazaoui, M.; Rouhet, J.

    1996-01-01

    The realization of an optical fibre sensor applied to cryogenic temperature measurement in harsh environments is presented. The measurement principle is based on the analysis of the decay-time of the fluorescence emitted by special doped crystals, the excited state lifetimes of which are greatly dep

  4. Demonstration of a refractometric sensor based on optical microfiber resonator

    OpenAIRE

    2008-01-01

    We experimentally demonstrated a refractometric sensor based on a coated optical microfiber coil resonator. It is robust, compact, and comprises an intrinsic fluidic channel. A sensitivity of about 40 nm/RIU (refractive index unit) has been measured, in agreement with predictions.

  5. Characterization of Integrated Optical Strain Sensors Based on Silicon Waveguides

    NARCIS (Netherlands)

    Westerveld, W.J.; Leinders, S.M.; Muilwijk, P.M.; Pozo, J.

    2013-01-01

    Microscale strain gauges are widely used in micro electro-mechanical systems (MEMS) to measure strains such as those induced by force, acceleration, pressure or sound. We propose all-optical strain sensors based on micro-ring resonators to be integrated with MEMS. We characterized the strain-induced

  6. Fiber optical magnetic field sensor for power generator monitoring

    Science.gov (United States)

    Willsch, Michael; Bosselmann, Thomas; Villnow, Michael

    2014-05-01

    Inside of large electrical engines such as power generators and large drives, extreme electric and magnetic fields can occur which cannot be measured electrically. Novel fiber optical magnetic field sensors are being used to characterize the fields and recognize inner faults of large power generators.

  7. Development of a rechargeable optical hydrogen peroxide sensor - sensor design and biological application

    DEFF Research Database (Denmark)

    Koren, Klaus; Østrup Jensen, Peter; Kühl, Michael

    2016-01-01

    . Quantifying H2O2 within biological samples is challenging and often not possible. Here we present a quasi-reversible fiber-optic sensor capable of measuring H2O2 concentrations ranging from 1-100 μM within different biological samples. Based on a Prussian blue/white redox cycle and a simple sensor recharging...... and readout strategy, H2O2 can be measured with high spatial (∼500 μm) and temporal (∼30 s) resolution. The sensor has a broad applicability both in complex environmental and biomedical systems, as demonstrated by (i) H2O2 concentration profile measurements in natural photosynthetic biofilms under light...

  8. Optical sensor based on a single CdS nanobelt.

    Science.gov (United States)

    Li, Lei; Yang, Shuming; Han, Feng; Wang, Liangjun; Zhang, Xiaotong; Jiang, Zhuangde; Pan, Anlian

    2014-04-23

    In this paper, an optical sensor based on a cadmium sulfide (CdS) nanobelt has been developed. The CdS nanobelt was synthesized by the vapor phase transportation (VPT) method. X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) results revealed that the nanobelt had a hexagonal wurtzite structure of CdS and presented good crystal quality. A single nanobelt Schottky contact optical sensor was fabricated by the electron beam lithography (EBL) technique, and the device current-voltage results showed back-to-back Schottky diode characteristics. The photosensitivity, dark current and the decay time of the sensor were 4 × 10⁴, 31 ms and 0.2 pA, respectively. The high photosensitivity and the short decay time were because of the exponential dependence of photocurrent on the number of the surface charges and the configuration of the back to back Schottky junctions.

  9. Optical Fiber Sensors for Aircraft Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Iker García

    2015-06-01

    Full Text Available Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors. Several practical applications for structures and engines we have been working on are reported in this article. Fiber Bragg gratings have been analyzed in detail, because they have proved to constitute the most promising technology in this field, and two different alternatives for strain measurements are also described. With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

  10. Optical Fiber Sensors for Aircraft Structural Health Monitoring.

    Science.gov (United States)

    García, Iker; Zubia, Joseba; Durana, Gaizka; Aldabaldetreku, Gotzon; Illarramendi, María Asunción; Villatoro, Joel

    2015-06-30

    Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors. Several practical applications for structures and engines we have been working on are reported in this article. Fiber Bragg gratings have been analyzed in detail, because they have proved to constitute the most promising technology in this field, and two different alternatives for strain measurements are also described. With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

  11. NEW OPTICAL SENSOR SUITE FOR ULTRAHIGH TEMPERATURE FOSSIL FUEL APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Russell G. May; Tony Peng; Tom Flynn

    2004-04-01

    Accomplishments during the first six months of a program to develop and demonstrate technology for the instrumentation of advanced powerplants are described. Engineers from Prime Research, LC and Babcock and Wilcox Research Center collaborated to generate a list of potential applications for robust photonic sensors in existing and future boiler plants. From that list, three applications were identified as primary candidates for initial development and demonstration of high-temperature sensors in an ultrasupercritical power plant. In addition, progress was made in the development of materials and methods to apply high-temperature optical claddings to sapphire fibers, in order to improve their optical waveguiding properties so that they can be used in the design and fabrication of high-temperature sensors. Through refinements in the processing steps, the quality of the interface between core and cladding of the fibers was improved, which is expected to reduce scattering and attenuation in the fibers.

  12. Optical Sensor Based on a Single CdS Nanobelt

    Directory of Open Access Journals (Sweden)

    Lei Li

    2014-04-01

    Full Text Available In this paper, an optical sensor based on a cadmium sulfide (CdS nanobelt has been developed. The CdS nanobelt was synthesized by the vapor phase transportation (VPT method. X-Ray Diffraction (XRD and Transmission Electron Microscopy (TEM results revealed that the nanobelt had a hexagonal wurtzite structure of CdS and presented good crystal quality. A single nanobelt Schottky contact optical sensor was fabricated by the electron beam lithography (EBL technique, and the device current-voltage results showed back-to-back Schottky diode characteristics. The photosensitivity, dark current and the decay time of the sensor were 4 × 104, 31 ms and 0.2 pA, respectively. The high photosensitivity and the short decay time were because of the exponential dependence of photocurrent on the number of the surface charges and the configuration of the back to back Schottky junctions.

  13. Utilization of Faraday Mirror in Fiber Optic Current Sensors

    Directory of Open Access Journals (Sweden)

    P. Fiala

    2008-12-01

    Full Text Available Fiber optic sensors dispose of some advantages in the field of electrical current and magnetic field measurement, like large bandwidth, linearity, light transmission possibilities. Unfortunately, they suffer from some parasitic phenomena. The crucial issue is the presence of induced and latent linear birefringence, which is imposed by the fiber manufacture imperfections as well as mechanical stress by fiber bending. In order to the linear birefringence compensation a promising method was chosen for pulsed current sensor design. The method employs orthogonal polarization conjugation by the back direction propagation of the light wave in the fiber. The Jones calculus analysis presents its propriety. An experimental fiber optic current sensor has been designed and realized. The advantage of the proposed method was proved considering to the sensitivity improvement.

  14. Optical fiber sensors measurement system and special fibers improvement

    Science.gov (United States)

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

    2017-06-01

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

  15. Fiber-optic surface plasmon resonant sensor with low-index anti-oxidation coating

    Institute of Scientific and Technical Information of China (English)

    Yong Chen; Rongsheng Zheng; Yonghua Lu; Pei Wang; Hai Ming

    2011-01-01

    A multimode fiber-optic surface plasmon resonance (SPR) sensor with a MgF2 film as a modulated layer is studied. The fiber-optic SPR sensor is investigated theoretically, specifically the influence of the dielectric protecting layer, using a four-layer model. The sensor is then fabricated with the optimal parameters suggested by the theoretical simulation. The sensor has a high sensitivity in the analyte refractive index (RI) range of 1.33-1.40. The best sensitivity of 4464 nm/RIU is achieved in the experiment. The use of dielectric film (MgF2) can not only modulate the resonance wavelength of the sensor, but also protect the silver film from oxidation.%A multimode fiber-optic surface plasmon resonance (SPR) sensor with a MgF2 film as a modulated layer is studied.The fiber-optic SPR sensor is investigated theoretically,specifically the influence of the dielectric protecting layer,using a four-layer model.The sensor is then fabricated with the optimal parameters suggested by the theoretical simulation.The sensor has a high sensitivity in the analyte refractive index (RI) range of 1.33-1.40.The best sensitivity of 4 464 nm/RIU is achieved in the experiment.The use of dielectric film (MgF2) can not only modulate the resonance wavelength of the sensor,but also protect the silver film from oxidation.Surface plasmon resonance (SPR) is a kind of coherent oscillation between the free electrons at a metal/dielectric interface and the optical wave.The hybridized excitation,called surface plasmon polariton (SPP),is the electromagnetic excitation that propagates along the interface as a longitudinal wave.At a given wavelength and angle that satisfy the wave-vector matching condition,the incident light will be intensively absorbed.Due to its high sensitivity to the refractive index (RI) of the adjacent material,the SPR phenomenon was firstly applied to gas detection in 1983[1].The SPR sensing technology has been widely used in the detection of biological and chemical analytes

  16. Structural Health Monitoring of Composite Structures Using Fiber Optic Sensors

    Science.gov (United States)

    Whitaker, Anthony

    Structural health monitoring is the process of detecting damage to a structure, where damage can be characterized as changes to material/mechanical properties including but not limited to plastically deforming the material or the modification of connections. Fiber optic cables with fiber Bragg gratings have emerged as a reliable method of locally measuring strains within a structure. During the manufacturing of composite structures, the fiber optic cables can be embedded between lamina plies, allowing the ability to measure strain at discrete locations within the structure as opposed to electrical strain gauges, which must typically be applied to the surface only. The fiber optic sensors may be used to see if the local strain at the sensor location is beyond desired limits, or the array response may be mined to determine additional information about the loading applied to the structure. The work presented in this thesis is to present novel and potential applications of FBG sensors being used to assess the health of the structure. The first application is the dual application of the FBG sensor as a method to determine the strain around a bolt connection as well as the preload of the fastener using a single fiber optic sensor. The composite material around the bolted connections experience stress concentrations and are often the location of damage to the structure from operational cyclic loading over the lifetime of the structure. The degradation can occur more quickly if the fastener is insufficiently tight to transfer load properly. The second application is the ability to locate the impact location of a projectile with damaging and non-damaging energy. By locating and quantifying the damage, the sensor array provides the basis for a structural health monitoring system that has the potential to determine if the damage is extensive enough to replace, or if the part can be salvaged and retrofitted.

  17. Adhesive bond failure monitoring with triboluminescent optical fiber sensor

    Science.gov (United States)

    Shohag, Md Abu S.; Hammel, Emily C.; Olawale, David O.; Okoli, Okenwa O.

    2016-04-01

    One of the most severe damage modes in modern wind turbines is the failure of the adhesive joints in the trailing edge of the large composite blades. The geometrical shape of the blade and current manufacturing techniques make the trailing edge of the wind turbine blade more sensitive to damage. Failure to timely detect this damage type may result in catastrophic failures, expensive system downtime, and high repair costs. A novel sensing system called the In-situ Triboluminescent Optical Fiber (ITOF) sensor has been proposed for monitoring the initiation and propagation of disbonds in composite adhesive joints. The ITOF sensor combines the triboluminescent property of ZnS:Mn with the many desirable features of optical fiber to provide in-situ and distributed damage sensing in large composite structures like the wind blades. Unlike other sensor systems, the ITOF sensor does not require a power source at the sensing location or for transmitting damage-induced signals to the hub of the wind turbine. Composite parts will be fabricated and the ITOF integrated within the bondline to provide in-situ and real time damage sensing. Samples of the fabricated composite parts with integrated ITOF will be subjected to tensile and flexural loads, and the response from the integrated sensors will be monitored and analyzed to characterize the performance of the ITOF sensor as a debonding damage monitoring system. In addition, C-scan and optical microscopy will be employed to gain greater insights into the damage propagation behavior and the signals received from the ITOF sensors.

  18. pH-responsive fluorescence chemical sensor constituted by conjugated polymers containing pyridine rings.

    Science.gov (United States)

    Adachi, Naoya; Kaneko, Yuki; Sekiguchi, Kazuki; Sugiyama, Hiroki; Sugeno, Masafumi

    2015-12-01

    Poly(p-pyridinium phenylene ethynylene)s (PPyPE) functionalized with alternating donor-acceptor repeat units were synthesized by a Pd-catalyzed Sonogashira coupling reaction between diethynyl monomer and di-iodopyridine for use as a pH-responsive fluorescence chemical sensor. The synthesized PPyPE, containing pyridine units, was characterized by FT-IR, (1)H and (13)C NMR, UV-visible and fluorescence spectroscopies. We investigated the relationship between changes of optical properties and protonation/deprotonation of PPyPE containing pyridine units in solution. Addition of HCl decreased and red-shifted the fluorescence intensity of the conjugated polymers that contained pyridine rings; fluorescence intensity of the polymers increased upon addition of NaOH solution. The synthesized PPyPE was found to be an effective and reusable chemical sensor for pH sensing.

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

    Science.gov (United States)

    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.

  20. Microstructured optical fiber refractive index sensor

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  1. Microstructured optical fiber refractive index sensor

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  2. Towards biochips using microstructured optical fiber sensors.

    Science.gov (United States)

    Rindorf, Lars; Høiby, Poul Erik; Jensen, Jesper Bo; Pedersen, Lars Hagsholm; Bang, Ole; Geschke, Oliver

    2006-08-01

    In this paper we present the first incorporation of a microstructured optical fiber (MOF) into biochip applications. A 16-mm-long piece of MOF is incorporated into an optic-fluidic coupler chip, which is fabricated in PMMA polymer using a CO(2) laser. The developed chip configuration allows the continuous control of liquid flow through the MOF and simultaneous optical characterization. While integrated in the chip, the MOF is functionalized towards the capture of a specific single-stranded DNA string by immobilizing a sensing layer on the microstructured internal surfaces of the fiber. The sensing layer contains the DNA string complementary to the target DNA sequence and thus operates through the highly selective DNA hybridization process. Optical detection of the captured DNA was carried out using the evanescent-wave-sensing principle. Owing to the small size of the chip, the presented technique allows for analysis of sample volumes down to 300 nL and the fabrication of miniaturized portable devices.

  3. Optical Fiber Pressure Sensor with Reference channel①

    Institute of Scientific and Technical Information of China (English)

    YUZhijing; TIANWei

    1997-01-01

    The principle of optical fiber pressure sensing probe with common diaphragm and the method for stabilizing the laser diodes are described in this paper at first.Then we discussed the improvement in characteristics of the system by means of taking the techniques of reference light channel and ratio measurement.

  4. Optical cloud detection from a disposable airborne sensor

    Science.gov (United States)

    Nicoll, Keri; Harrison, R. Giles; Brus, David

    2016-04-01

    In-situ measurement of cloud droplet microphysical properties is most commonly made from manned aircraft platforms due to the size and weight of the instrumentation, which is both costly and typically limited to sampling only a few clouds. This work describes the development of a small, lightweight (DMT Cloud and Aerosol Spectrometer (CAS) which measures cloud droplets in the size range from 0.5 to 50 microns. Both sensors were installed at the hill top observatory of Sammaltunturi during a field campaign in October and November 2015, which experienced long periods of immersion inside cloud. Preliminary analysis shows very good agreement between the CAPS and the disposable cloud sensor for cloud droplets >5micron effective diameter. Such data and calibration of the sensor will be discussed here, as will simultaneous balloon launches of the optical cloud sensor through the same cloud layers.

  5. Toluene optical fibre sensor based on air microcavity in PDMS

    Science.gov (United States)

    Kacik, Daniel; Martincek, Ivan

    2017-03-01

    We prepared and demonstrated a compact, simple-to-fabricate, air microcavity in polydimethylsiloxane (PDMS) placed at the end of a single-mode optical fibre. This microcavity creates a Fabry-Perot interferometer sensor able to measure concentrations of toluene vapour in air. Operation of the sensor is provided by diffusion of the toluene vapour to the PDMS, and the consequent extension of length d of the air microcavity in PDMS. The sensor response for the presence of vapours is fast and occurs within a few seconds. By using the prepared sensor toluene vapour concentration in air can be measured in the range from about 0.833 g.m-3 to saturation, with better sensitivity than 0.15 nm/g.m-3 up to maximal sensitivity 1.4 nm/g.m-3 at around concentration 100 g.m-3 in time 5 s.

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

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

  8. 1st International Conference on Fiber-Optic Rotation Sensors

    CERN Document Server

    Arditty, Hervé

    1982-01-01

    Currently there is considerable interest in the application of optical meth­ ods for the measurement of absolute rotation. Active approaches, so-called ring laser gyros, have been under serious development for at least 15 years. More recently, passive approaches using ring resonators or multi turn fiber interferometers have also demonstrated much pro~ise. The only previous conference devoted exclusively to optical rotation sensors, held in 1978 in San Diego, California, was organized by the Society of Photo-optical Instru­ mentation Engineers(S.P.I.E.J. Although the main emphasis at that conference was on ring laser gyros, a number of papers were also included that described the early development of fiber gyroscopes. Since then the field of fiber optic rotation sensors has grown so rapidly that a conference devoted primarily to this subject was needed. The First International Conference on Fiber-Optic Rotation Sensors was held at the Massachusetts Institute of Technology, Cambridge, Massachusetts, Nove~­ b...

  9. Miniature fiber optic sensor based on fluorescence energy transfer

    Science.gov (United States)

    Meadows, David L.; Schultz, Jerome S.

    1992-04-01

    Optical fiber biosensors based on fluorescence assays have several distinct advantages when measuring biological analytes such as metabolites, cofactors, toxins, etc. Not only are optical signals immune to electronic interferences, but the polychromatic nature of most fluorochemical assays provides more potentially useful data about the system being studied. One of the most common difficulties normally encountered with optical biosensors is the inability to routinely recalibrate the optical and electronic components of the system throughout the life of the sensor. With this in mind, we present an optical fiber assay system for glucose based on a homogeneous singlet/singlet energy transfer assay along with the electronic instrumentation built to support the sensor system. In the sensor probe, glucose concentrations are indirectly measured from the level of fluorescence quenching caused by the homogeneous competition assay between TRITC labeled concanavalin A (receptor) and FITC labeled Dextran (ligand). The FITC signal is used to indicate glucose concentrations and the TRITC signal is used for internal calibration. Data is also presented on a protein derivatization procedure that was used to prevent aggregation of the receptor protein in solution. Also, a molecular model is described for the singlet/singlet energy transfer interactions that can occur in a model system composed of a monovalent ligand (FITC labeled papain) and a monovalent receptor (TRITC labeled concanavalin A).

  10. Insect-Inspired Optical-Flow Navigation Sensors

    Science.gov (United States)

    Thakoor, Sarita; Morookian, John M.; Chahl, Javan; Soccol, Dean; Hines, Butler; Zornetzer, Steven

    2005-01-01

    Integrated circuits that exploit optical flow to sense motions of computer mice on or near surfaces ( optical mouse chips ) are used as navigation sensors in a class of small flying robots now undergoing development for potential use in such applications as exploration, search, and surveillance. The basic principles of these robots were described briefly in Insect-Inspired Flight Control for Small Flying Robots (NPO-30545), NASA Tech Briefs, Vol. 29, No. 1 (January 2005), page 61. To recapitulate from the cited prior article: The concept of optical flow can be defined, loosely, as the use of texture in images as a source of motion cues. The flight-control and navigation systems of these robots are inspired largely by the designs and functions of the vision systems and brains of insects, which have been demonstrated to utilize optical flow (as detected by their eyes and brains) resulting from their own motions in the environment. Optical flow has been shown to be very effective as a means of avoiding obstacles and controlling speeds and altitudes in robotic navigation. Prior systems used in experiments on navigating by means of optical flow have involved the use of panoramic optics, high-resolution image sensors, and programmable imagedata- processing computers.

  11. Development of Metal Oxide Nanostructure-based Optical Sensors for Fossil Fuel Derived Gases Measurement at High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kevin P. [Univ. of Pittsburgh, PA (United States)

    2015-02-13

    This final technical report details research works performed supported by a Department of Energy grant (DE-FE0003859), which was awarded under the University Coal Research Program administrated by National Energy Technology Laboratory. This research program studied high temperature fiber sensor for harsh environment applications. It developed two fiber optical sensor platform technology including regenerative fiber Bragg grating sensors and distributed fiber optical sensing based on Rayleigh backscattering optical frequency domain reflectometry. Through the studies of chemical and thermal regenerative techniques for fiber Bragg grating (FBG) fabrication, high-temperature stable FBG sensors were successfully developed and fabricated in air-hole microstructured fibers, high-attenuation fibers, rare-earth doped fibers, and standard telecommunication fibers. By optimizing the laser processing and thermal annealing procedures, fiber grating sensors with stable performance up to 1100°C have been developed. Using these temperature-stable FBG gratings as sensor platform, fiber optical flow, temperature, pressure, and chemical sensors have been developed to operate at high temperatures up to 800°C. Through the integration of on-fiber functional coating, the use of application-specific air-hole microstructural fiber, and application of active fiber sensing scheme, distributed fiber sensor for temperature, pressure, flow, liquid level, and chemical sensing have been demonstrated with high spatial resolution (1-cm or better) with wide temperature ranges. These include the demonstration of 1) liquid level sensing from 77K to the room temperature, pressure/temperature sensing from the room temperature to 800C and from the 15psi to 2000 psi, and hydrogen concentration measurement from 0.2% to 10% with temperature ranges from the room temperature to 700°C. Optical sensors developed by this program has broken several technical records including flow sensors with the highest

  12. Development of Metal Oxide Nanostructure-based Optical Sensors for Fossil Fuel Derived Gases Measurement at High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kevin

    2014-08-31

    This final technical report details research works performed supported by a Department of Energy grant (DE-FE0003859), which was awarded under the University Coal Research Program administrated by National Energy Technology Laboratory. This research program studied high temperature fiber sensor for harsh environment applications. It developed two fiber optical sensor platform technology including regenerative fiber Bragg grating sensors and distributed fiber optical sensing based on Rayleigh backscattering optical frequency domain reflectometry. Through the studies of chemical and thermal regenerative techniques for fiber Bragg grating (FBG) fabrication, high-temperature stable FBG sensors were successfully developed and fabricated in air-hole microstructured fibers, high-attenuation fibers, rare-earth doped fibers, and standard telecommunication fibers. By optimizing the laser processing and thermal annealing procedures, fiber grating sensors with stable performance up to 1100oC have been developed. Using these temperature-stable FBG gratings as sensor platform, fiber optical flow, temperature, pressure, and chemical sensors have been developed to operate at high temperatures up to 800oC. Through the integration of on-fiber functional coating, the use of application-specific air-hole microstructural fiber, and application of active fiber sensing scheme, distributed fiber sensor for temperature, pressure, flow, liquid level, and chemical sensing have been demonstrated with high spatial resolution (1-cm or better) with wide temperature ranges. These include the demonstration of 1) liquid level sensing from 77K to the room temperature, pressure/temperature sensing from the room temperature to 800C and from the 15psi to 2000 psi, and hydrogen concentration measurement from 0.2% to 10% with temperature ranges from the room temperature to 700C. Optical sensors developed by this program has broken several technical records including flow sensors with the highest

  13. Fiber-Optic Vibration Sensor Based on Multimode Fiber

    Directory of Open Access Journals (Sweden)

    I. Lujo

    2008-06-01

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

  14. Optical sensor for measuring humidity, strain and temperature

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to an optical sensor (100) adapted to measure at least three physical parameters, said optical sensor comprising a polymer-based optical waveguide structure comprising a first Bragg grating structure (101) being adapted to provide information about a first, a second...... and a third physical parameter, a second Bragg grating structure (102) being adapted to provide information about the second and the third physical parameter only, and a third Bragg grating structure (103) being adapted to provide information about the third physical parameter only. The invention further...... relates to a method for measuring the first, the second and the third physical parameter. Preferably, the first, the second and the third physical parameter, are humidity, strain and temperature, respectively....

  15. Optical fiber temperature sensor based on wavelength-dependent detection

    Institute of Scientific and Technical Information of China (English)

    Zhigang Li(李志刚); Zhenhui Du(杜振辉); Baoguang Wang(王宝光); Chengzhi Jiang(蒋诚志)

    2004-01-01

    Semiconductor fiber temperature sensors have been used widely in many fields, but most of them pick up temperature by measuring the optical intensity of certain fixed narrow-band in absorption spectrum.Furthermore, they are sensitive to the loss of optical intensity and the fluctuation of light source power.The novel temperature measurement system proposed in this paper is based on the semiconductor absorption theory and the spectral analysis of method. To measure temperature, the sensor model detects not the certain narrow-band spectrum but the most spectra of the optical absorption edge. Therefore the measurement accuracy and the stability can be improved greatly. Experimental results are in agreement with theoretical analysis results perfectly.

  16. Fiber optic stress-independent helical torsion sensor.

    Science.gov (United States)

    Fernandes, Luís A; Grenier, Jason R; Aitchison, J Stewart; Herman, Peter R

    2015-02-15

    Femtosecond laser-fabricated waveguides have been formed into helical paths throughout the cladding of single-mode optical fibers to demonstrate a strain-independent fiber torsion sensor. A comparison between a Bragg grating sensor and a Mach-Zehnder based on helical waveguides (HWs) showed a much weaker twist sensitivity of 1.5 pm/(rad/m) for the grating in contrast with a value of 261 pm/(rad/m) for the interferometer. The HW geometry provided an unambiguous determination of the rotational direction of the twist while facilitating a convenient and efficient means for optical coupling into the single-mode core of the fiber. The flexible three-dimensional writing by the femtosecond laser fabrication method enabled the direct inscription of compact and robust optical cladding devices without the need for combining or splicing multiple-fiber segments.

  17. Detection of Aeromonas hydrophila Using Fiber Optic Microchannel Sensor

    Directory of Open Access Journals (Sweden)

    Samla Gauri

    2017-01-01

    Full Text Available This research focuses on the detection of Aeromonas hydrophila using fiber optic microchannel biosensor. Microchannel was fabricated by photolithography method. The fiber optic was chosen as signal transmitting medium and light absorption characteristic of different microorganisms was investigated for possible detection. Experimental results showed that Aeromonas hydrophila can be detected at the region of UV-Vis spectra between 352 nm and 354 nm which was comparable to measurement provided by UV spectrophotometer and also theoretical calculation by Beer-Lambert Absorption Law. The entire detection can be done in less than 10 minutes using a total volume of 3 μL only. This result promises good potential of this fiber optic microchannel sensor as a reliable, portable, and disposable sensor.

  18. Pyridine Vapors Detection by an Optical Fibre Sensor

    Directory of Open Access Journals (Sweden)

    Alberto Fernandez-Gutiérrez

    2008-02-01

    Full Text Available An optical fibre sensor has been implemented towards pyridine vapors detection;to achieve this, a novel vapochromic material has been used, which, in solid state, suffers achange in colour from blue to pink-white in presence of pyridine vapours. This complex isadded to a solution of PVC (Poly Vinyl Chloride, TBP (Tributylphosphate andtetrahydrofuran (THF, forming a plasticized matrix; by dip coating technique, the sensingmaterial is fixed onto a cleaved ended optical fibre. The fabrication process was optimizedin terms of number of dips and dipping speed, evaluating the final devices by dynamicrange. Employing a reflection set up, the absorbance spectra and changes in the reflectedoptical power of the sensors were registered to determine their response. A linear relationbetween optical power versus vapor concentration was obtained, with a detection limit of 1ppm (v/v.

  19. Optical sensor instrumentation using absorption- and fluorescence-based capillary waveguide optrodes

    Science.gov (United States)

    Weigl, Bernhard H.; Draxler, Sonja; Kieslinger, Dietmar; Lehmann, H.; Trettnak, Wolfgang; Wolfbeis, Otto S.; Lippitsch, Max E.

    1995-09-01

    An analytical instrument comprising absorption- and fluorescence-based capillary waveguide optrodes (CWOs) is described. Glass capillaries with a chemically sensitive coating on the inner surface are used for optical chemical sensing in gaseous and liquid samples. In case of absorption-based CWOs, light from a LED is coupled into and out of the capillary under a defined angle via a rigid waveguide and an immersion coupler. The coated glass capillary forms an inhomogeneous waveguide, in which the light is guided in both the glass and the coating. The portion of the light which is absorbed in the chemically sensitive coating is proportional to a chemcial concentration or activity. This principle is demonstrated with a pCO2-sensitive inner coating. Typical relative light intensity signal changes with this type of optical interrogation are 98%, with an active capillary length of 10 mm. For fluorescence- based CWOs, the excitation light from an LED is coupled diffusely into the glass capillary and the optical sensor layer. A major portion of the excited fluorescence light is then collected within the coated capillary, and guided to the photodiode, which is located on the distal end of the capillary waveguide. Hereby, the excitation light is separated very efficiently from the fluorescent light. As an example, a CWO for pO2 is described. By applying this optical geometry, it was possible to utilize fluorescence decay time of the sensor layer as the transducer signal even when using solid state components (LEDs and photodiodes).

  20. 75 FR 34988 - Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems Technology...

    Science.gov (United States)

    2010-06-21

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

  1. 78 FR 17187 - Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems Technology...

    Science.gov (United States)

    2013-03-20

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

  2. 77 FR 73456 - Notice of Intent To Grant Exclusive Patent License; Fiber Optic Sensor Systems Technology...

    Science.gov (United States)

    2012-12-10

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

  3. Optical coherent detection Brillouin distributed optical fiber sensor based on orthogonal polarization diversity reception

    Institute of Scientific and Technical Information of China (English)

    Muping Song; Bin Zhao; Xianmin Zhang

    2005-01-01

    In Brillouin distributed optical fiber sensor, using optical coherent detection to detect Brillouin scattering optical signal is a good method, but there exists the polarization correlated detection problem. A novel detecting scheme is presented and demonstrated experimentally, which adopts orthogonal polarization diversity reception to resolve the polarization correlated detection problem. A laser is used as pump and reference light sources, a microwave electric-optical modulator (EOM) is adopted to produce frequency shift reference light, a polarization controller is used to control the polarization of the reference light which is changed into two orthogonal polarization for two adjacent acquisition periods. The Brillouin scattering light is coherently detected with the reference light, and the Brillouin scattering optical signal is taken out based on Brillouin frequency shift. After electronic processing, better Brillouin distributed sensing signal is obtained. A 25-km Brillouin distributed optical fiber sensor is achieved.

  4. A small sensor with matched optical antenna

    Energy Technology Data Exchange (ETDEWEB)

    Shepelev, A.V. [Russian Academy of Sciences, Moscow (Russian Federation). Central Design Bureau for Unique Instrumentation

    1994-12-31

    Each device for radiation registration in the radio range contains an antenna. Mainly it is the antenna dimension that determines the sensitivity of the device. Can an antenna for the registration of more short wave radiation be constructed? The main feature of antenna action is the conversion of the incident radiation mode into the mode passing through the antenna. At this moment the radiation brightness (which is equivalent to a number of photons per mode) can increase. In accordance with the geometric optics (Shtraubel theorem) the length and mirror systems cannot raise the radiation brightness in principle and cannot be treated as an antenna. Recently it was established that definite optical processes and systems give a possibility of increasing the full radiation brightness. The device for effective registration of short wave radiation is worked out on the basis of these processes.

  5. Recovering Signals from Optical Fiber Interferometric Sensors

    Science.gov (United States)

    1991-06-01

    explained in numerous books on operational amplifiers (for example, see Sedra and Smith [Ref. 171) and so will not be further discussed here, except to say...618. 1 October 1982. 17. Sedra , A. S.. and Smith .- K. C.. Microelectronic CrciimHolt. Rinehart and Winston, 1982. 18. Abramowitz, M. and- Stegun. I.A...Interfcromctcrse, Applied Optics. Volume 21. Number 4. 689-693. 1982. 46. Smith , L. and Sheingold, D.H.. "Noise and Operational Amplifier Circuits’, Analog

  6. Nanostructure Engineered Chemical Sensors for Hazardous Gas and Vapor Detection

    Science.gov (United States)

    Li, Jing; Lu, Yijiang

    2005-01-01

    A nanosensor technology has been developed using nanostructures, such as single walled carbon nanotubes (SWNTs) and metal oxides nanowires or nanobelts, on a pair of interdigitated electrodes (IDE) processed with a silicon based microfabrication and micromachining technique. The IDE fingers were fabricated using thin film metallization techniques. Both in-situ growth of nanostructure materials and casting of the nanostructure dispersions were used to make chemical sensing devices. These sensors have been exposed to hazardous gases and vapors, such as acetone, benzene, chlorine, and ammonia in the concentration range of ppm to ppb at room temperature. The electronic molecular sensing in our sensor platform can be understood by electron modulation between the nanostructure engineered device and gas molecules. As a result of the electron modulation, the conductance of nanodevice will change. Due to the large surface area, low surface energy barrier and high thermal and mechanical stability, nanostructured chemical sensors potentially can offer higher sensitivity, lower power consumption and better robustness than the state-of-the-art systems, which make them more attractive for defense and space applications. Combined with MEMS technology, light weight and compact size sensors can be made in wafer scale with low cost.

  7. Wireless Chemical Sensor and Sensing Method for Use Therewith

    Science.gov (United States)

    Woodard, Stanley E. (Inventor); Oglesby, Donald M. (Inventor); Taylor, Bryant D. (Inventor)

    2016-01-01

    A wireless chemical sensor includes an electrical conductor and a material separated therefrom by an electric insulator. The electrical conductor is an unconnected open-circuit shaped for storage of an electric field and a magnetic field. In the presence of a time-varying magnetic field, the first electrical conductor resonates to generate harmonic electric and magnetic field responses. The material is positioned at a location lying within at least one of the electric and magnetic field responses so-generated. The material changes in electrical conductivity in the presence of a chemical-of-interest.

  8. Optical Sensors based on Raman Effects

    DEFF Research Database (Denmark)

    Jernshøj, Kit Drescher

    Formålet med denne afhandling er at give en systematisk og uddybende videnskabelig diskussion af molekylær Raman spredning, som kan danne grundlag for udviklingen af molekylespecifikke optiske sensorer til on-site, ikke-destruktiv måling. Afhandlingen falder i tre dele, to teoriafsnit, hvor første...... data fra denne type eksperimenter betyde et øget informationsindhold til anvendelse i den multivariate analyse. Diskussionen er bygget op omkring tre forskellige typer klassifikationsproblemer, hvor der i den første type sker en perturbering, som resulterer i enten en nedgang i symmetri eller en...... energiopsplitning for den ene molekylære specie ud af to tilstede i en opløsning. I det andet type klassifikationsproblem bygger det øgede informationsindhold på en forskydning af den elektroniske absorption og endelig i det tredje klassifikationsproblem er det en molekylær aggregering, der finder sted. I...

  9. Programmable logic controller optical fibre sensor interface module

    Science.gov (United States)

    Allwood, Gary; Wild, Graham; Hinckley, Steven

    2011-12-01

    Most automated industrial processes use Distributed Control Systems (DCSs) or Programmable Logic Controllers (PLCs) for automated control. PLCs tend to be more common as they have much of the functionality of DCSs, although they are generally cheaper to install and maintain. PLCs in conjunction with a human machine interface form the basis of Supervisory Control And Data Acquisition (SCADA) systems, combined with communication infrastructure and Remote Terminal Units (RTUs). RTU's basically convert different sensor measurands in to digital data that is sent back to the PLC or supervisory system. Optical fibre sensors are becoming more common in industrial processes because of their many advantageous properties. Being small, lightweight, highly sensitive, and immune to electromagnetic interference, means they are an ideal solution for a variety of diverse sensing applications. Here, we have developed a PLC Optical Fibre Sensor Interface Module (OFSIM), in which an optical fibre is connected directly to the OFSIM located next to the PLC. The embedded fibre Bragg grating sensors, are highly sensitive and can detect a number of different measurands such as temperature, pressure and strain without the need for a power supply.

  10. Fiber-Optic Sensor for Aircraft Lightning Current Measurement

    Science.gov (United States)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George G.; Mata, Carlos T.; Mata, Angel G.; Snyder, Gary P.

    2012-01-01

    An electric current sensor based on Faraday rotation effect in optical fiber was developed for measuring aircraft lightning current. Compared to traditional sensors, the design has many advantages including the ability to measure total current and to conform to structure geometries. The sensor is also small, light weight, non-conducting, safe from interference, and free of hysteresis and saturation. Potential applications include characterization of lightning current waveforms, parameters and paths, and providing environmental data for aircraft certifications. In an optical fiber as the sensing medium, light polarization rotates when exposed to a magnetic field in the direction of light propagation. By forming closed fiber loops around a conductor and applying Ampere s law, measuring the total light rotation yields the enclosed current. A reflective polarimetric scheme is used, where polarization change is measured after the polarized light travels round-trip through the sensing fiber. The sensor system was evaluated measuring rocket-triggered lightning over the 2011 summer. Early results compared very well against a reference current shunt resistor, demonstrating the sensor s accuracy and feasibility in a lightning environment. While later comparisons show gradually increasing amplitude deviations for an undetermined cause, the overall waveforms still compared very well.

  11. Fiber-optic Fabry-Pérot strain sensor based on graded-index multimode fiber

    Institute of Scientific and Technical Information of China (English)

    Tian Zhao; Yuan Gong; Yunjiang Rao; Yu Wu; Zengling Ran; Huijuan Wu

    2011-01-01

    By using a graded-index multimode fiber (GI-MMF) with a relatively flat index profile and high refractive index of the fiber core, a microextrinsic fiber-optic Fabry-Pérot interferometric (MEFPI) strain sensor is fabricated through chemical etching and fusion splicing. Higher reflectance of the microcavity is obtained due to the less-curved inner wall in the center of the fiber core after etching and higher index contrast between the GI-MMF core and air. The maximum reflection of the sensor is enhanced 12 dB than that obtained by etching of the Er- or B-doped fibers. High fringe contrast of 22 dB is obtained. The strain and temperature responses of the MEFPI sensors are investigated in this experiment. Good linearity and high sensitivity axe achieved, with wavelength-strain and wavelength-temperature sensitivities of 7.82 pm/μεand 5.01 pm/℃, respectively.%@@ By using a graded-index multimode fiber (GI-MMF) with a relatively flat index profile and high refractive index of the fiber core, a microextrinsic fiber-optic Fabry-Pérot interferometric (MEFPI) strain sensor is fabricated through chemical etching and fusion splicing.Higher reflectance of the microcavity is obtained due to the less-curved inner wall in the center of the fiber core after etching and higher index contrast between the GI-MMF core and air.

  12. New Optical Sensor Suite for Ultrahigh Temperature Fossil Fuel Applications

    Energy Technology Data Exchange (ETDEWEB)

    Russell G. May; Tony Peng; Gary Pickrell

    2005-10-31

    Development of practical, high-temperature optical claddings for improved waveguiding in sapphire fibers continued during the reporting period. A set of designed experiments using the Taguchi method was undertaken to efficiently determine the optimal set of processing variables to yield clad fibers with good optical and mechanical properties. Eighteen samples of sapphire fibers were prepared with spinel claddings, each with a unique set of variables. Statistical analyses of the results were then used to predict the set of factors that would result in a spinel cladding with the optimal geometrical, mechanical, and optical properties. To confirm the predictions of the Taguchi analysis, sapphire fibers were clad with the magnesium aluminate spinel coating using the predicted optimal set of factors. In general, the clad fibers demonstrated high quality, exceeding the best results obtained during the Phase I effort. Tests of the high-temperature stability of the clad fibers were also conducted. The results indicated that the clad fibers were stable at temperatures up to 1300 C for the duration of the three day test. At the higher temperatures, some changes in the geometry of the fibers were observed. The design, fabrication, and testing of a sapphire sensor for measurement of temperature was undertaken. The specific sensor configuration uses a polished sapphire wafer as the temperature-sensitive element. The wafer is attached to a sapphire fiber (clad or unclad), and interrogated as a Fabry-Perot sensor. Methods for assembling the sensor were investigated. A prototype sensor was fabricated and tested at room temperature and elevated temperatures. Results were difficult to interpret, due to the presence of modal noise which was found to result from the use of a spectrometer that was not designed for use with multimode fibers. A spectrometer optimized for use of multimode fiber has been obtained, and further evaluation of the sapphire temperature sensor is continuing.

  13. Wavefront sensors and algorithms for adaptive optical systems

    Science.gov (United States)

    Lukin, V. P.; Botygina, N. N.; Emaleev, O. N.; Konyaev, P. A.

    2010-07-01

    The results of recent works related to techniques and algorithms for wave-front (WF) measurement using Shack-Hartmann sensors show their high efficiency in solution of very different problems of applied optics. The goal of this paper was to develop a sensitive Shack-Hartmann sensor with high precision WF measurement capability on the base of modern technology of optical elements making and new efficient methods and computational algorithms of WF reconstruction. The Shack-Hartmann sensors sensitive to small WF aberrations are used for adaptive optical systems, compensating the wave distortions caused by atmospheric turbulence. A high precision Shack-Hartmann WF sensor has been developed on the basis of a low-aperture off-axis diffraction lens array. The device is capable of measuring WF slopes at array sub-apertures of size 640×640 μm with an error not exceeding 4.80 arcsec (0.15 pixel), which corresponds to the standard deviation equal to 0.017λ at the reconstructed WF with wavelength λ . Also the modification of this sensor for adaptive system of solar telescope using extended scenes as tracking objects, such as sunspot, pores, solar granulation and limb, is presented. The software package developed for the proposed WF sensors includes three algorithms of local WF slopes estimation (modified centroids, normalized cross-correlation and fast Fourierdemodulation), as well as three methods of WF reconstruction (modal Zernike polynomials expansion, deformable mirror response functions expansion and phase unwrapping), that can be selected during operation with accordance to the application.

  14. Future electro-optical sensors and processing in urban operations

    Science.gov (United States)

    Grönwall, Christina; Schwering, Piet B.; Rantakokko, Jouni; Benoist, Koen W.; Kemp, Rob A. W.; Steinvall, Ove; Letalick, Dietmar; Björkert, Stefan

    2013-10-01

    In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of local, distributed and centralized processing are proposed. In this way one can match processing functionality to the required power, and available communication systems data rates, to obtain the desired reaction times. In the study, three priority scenarios were defined. For these scenarios, present-day and future sensors and signal processing technologies were studied. The priority scenarios were camp protection, patrol and house search. A method for analyzing information quality in single and multi-sensor systems has been applied. A method for estimating reaction times for transmission of data through the chain of command has been proposed and used. These methods are documented and can be used to modify scenarios, or be applied to other scenarios. Present day data processing is organized mainly locally. Very limited exchange of information with other platforms is present; this is performed mainly at a high information level. Main issues that arose from the analysis of present-day systems and methodology are the slow reaction time due to the limited field of view of present-day sensors and the lack of robust automated processing. Efficient handover schemes between wide and narrow field of view sensors may however reduce the delay times. The main effort in the study was in forecasting the signal processing of EO-sensors in the next ten to twenty years. Distributed processing is proposed between hand-held and vehicle based sensors. This can be accompanied by cloud processing on board several vehicles. Additionally, to perform sensor fusion on sensor data originating from different platforms, and making full use of UAV imagery, a combination of distributed and

  15. Fabrication of fiber-optic localized surface plasmon resonance sensor and its application to detect antibody-antigen reaction of interferon-gamma

    Science.gov (United States)

    Jeong, Hyeon-Ho; Erdene, Norov; Lee, Seung-Ki; Jeong, Dae-Hong; Park, Jae-Hyoung

    2011-12-01

    A fiber-optic localized surface plasmon (FO LSPR) sensor was fabricated by gold nanoparticles (Au NPs) immobilized on the end-face of an optical fiber. When Au NPs were formed on the end-face of an optical fiber by chemical reaction, Au NPs aggregation occurred and the Au NPs were immobilized in various forms such as monomers, dimers, trimers, etc. The component ratio of the Au NPs on the end-face of the fabricated FO LSPR sensor was slightly changed whenever the sensors were fabricated in the same condition. Including this phenomenon, the FO LSPR sensor was fabricated with high sensitivity by controlling the density of Au NPs. Also, the fabricated sensors were measured for the resonance intensity for the different optical systems and analyzed for the effect on sensitivity. Finally, for application as a biosensor, the sensor was used for detecting the antibody-antigen reaction of interferon-gamma.

  16. Microbend fiber optic sensor for perioperative pediatric vital signs monitoring

    Science.gov (United States)

    Chen, Zhihao; Hee, Hwan Ing; Ng, Soon Huat; Teo, Ju Teng; Yang, Xiufeng; Wang, Dier

    2017-02-01

    We have demonstrated a highly sensitive microbend fiber optic sensor for perioperative pediatric vital signs monitoring that is free from direct contact with skin, cableless, electromagnetic interference free and low cost. The feasibility of our device was studied on infants undergoing surgery and 10 participants ranging from one month to 12 months were enrolled. The sensor was placed under a barrier sheet on the operating table. All patients received standard intraoperative monitoring. The results showed good agreement in heart rate and respiratory rate between our device and the standard physiological monitoring when signals are clean.

  17. Ground strain measuring system using optical fiber sensors

    Science.gov (United States)

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

    2001-08-01

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

  18. Optical Fiber High Temperature Sensor Instrumentation for Energy Intensive Industries

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-14

    This report summarizes technical progress during the program “Optical Fiber High Temperature Sensor Instrumentation for Energy Intensive Industries”, performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The objective of this program was to use technology recently invented at Virginia Tech to develop and demonstrate the application of self-calibrating optical fiber temperature and pressure sensors to several key energy-intensive industries where conventional, commercially available sensors exhibit greatly abbreviated lifetimes due primarily to environmental degradation. A number of significant technologies were developed under this program, including • a laser bonded silica high temperature fiber sensor with a high temperature capability up to 700°C and a frequency response up to 150 kHz, • the world’s smallest fiber Fabry-Perot high temperature pressure sensor (125 x 20 μm) with 700°C capability, • UV-induced intrinsic Fabry-Perot interferometric sensors for distributed measurement, • a single crystal sapphire fiber-based sensor with a temperature capability up to 1600°C. These technologies have been well demonstrated and laboratory tested. Our work plan included conducting major field tests of these technologies at EPRI, Corning, Pratt & Whitney, and Global Energy; field validation of the technology is critical to ensuring its usefulness to U.S. industries. Unfortunately, due to budget cuts, DOE was unable to follow through with its funding commitment to support Energy Efficiency Science Initiative projects and this final phase was eliminated.

  19. Optical design of rotationally symmetric triangulation sensors with low-cost detectors based on reflective optics

    Science.gov (United States)

    Ott, Peter

    2003-05-01

    Classical triangulation sensors exhibit an orientation depend signal if the scattering properties of the work-piece are not symmetrical like at curved surface locations. This problem is avoided by rotational symmetric triangulation sensors. Due to this attractive property in a lot of applications such a sensor was introduced very recently on the market. This sensor is based on refractive optics and a special PSD detector, both custom made resulting in high costs. Additionally, the existing optical design approach does not offer an optical layout to start with, thus a good amount of trial and error is required and non-optimal solutions are probable. Therefore, there is great interest for a clear optical design strategy that results in layouts that are suitable also to use low cost commercial available detectors, such as CCD or CMOS image detectors. In this paper such a design procedure is presented for optical designs that use reflecting optical surfaces. Several solutions are depicted and discussed. The designs are not only attractive from the optical point of view and from detector considerations, but also from opto-mechanical design issues. For example designs with only one opto-mechanical part are possible. The resulting optical designs consist of aspherical surfaces which are obtained directly by using only some new relations of first order optics for off-axis objects. The designs are validated by exact ray tracing. These ray tracing results show already very good performance. Nevertheless, it was possible to further optimize the optical designs very efficiently using ray tracing software, thus yielding improved optical properties.

  20. Fourier optics analysis of grating sensors with tilt errors.

    Science.gov (United States)

    Ferhanoglu, Onur; Toy, M Fatih; Urey, Hakan

    2011-06-15

    Dynamic diffraction gratings can be microfabricated with precision and offer extremely sensitive displacement measurements and light intensity modulation. The effect of pure translation of the moving part of the grating on diffracted order intensities is well known. This study focuses on the parameters that limit the intensity and the contrast of the interference. The effects of grating duty cycle, mirror reflectivities, sensor tilt and detector size are investigated using Fourier optics theory and Gaussian beam optics. Analytical findings reveal that fringe visibility becomes <0.3 when the optical path variation exceeds half the wavelength within the grating interferometer. The fringe visibility can be compensated by monitoring the interfering portion of the diffracted order light only through detector size reduction in the expense of optical power. Experiments were conducted with a grating interferometer that resulted in an eightfold increase in fringe visibility with reduced detector size, which is in agreement with theory. Findings show that diffraction grating readout principle is not limited to translating sensors but also can be used for sensors with tilt or other deflection modes.

  1. Optical-frequency-comb based ultrasound sensor

    Science.gov (United States)

    Minamikawa, Takeo; Ogura, Takashi; Masuoka, Takashi; Hase, Eiji; Nakajima, Yoshiaki; Yamaoka, Yoshihisa; Minoshima, Kaoru; Yasui, Takeshi

    2017-03-01

    Photo-acoustic imaging is a promising modality for deep tissue imaging with high spatial resolution in the field of biology and medicine. High penetration depth and spatial resolution of the photo-acoustic imaging is achieved by means of the advantages of optical and ultrasound imaging, i.e. tightly focused beam confines ultrasound-generated region within micrometer scale and the ultrasound can propagate through tissues without significant energy loss. To enhance the detection sensitivity and penetration depth of the photo-acoustic imaging, highly sensitive ultrasound detector is greatly desired. In this study, we proposed a novel ultrasound detector employing optical frequency comb (OFC) cavity. Ultrasound generated by the excitation of tightly focused laser beam onto a sample was sensed with a part of an OFC cavity, being encoded into OFC. The spectrally encoded OFC was converted to radio-frequency by the frequency link nature of OFC. The ultrasound-encoded radio-frequency can therefore be directly measured with a high-speed photodetector. We constructed an OFC cavity for ultrasound sensing with a ring-cavity erbium-doped fiber laser. We provided a proof-of-principle demonstration of the detection of ultrasound that was generated by a transducer operating at 10 MHz. Our proposed approach will serve as a unique and powerful tool for detecting ultrasounds for photo-acoustic imaging in the future.

  2. Microstructured and Photonic Bandgap Fibers for Applications in the Resonant Bio- and Chemical Sensors

    Directory of Open Access Journals (Sweden)

    Maksim Skorobogatiy

    2009-01-01

    Full Text Available We review application of microstructured and photonic bandgap fibers for designing resonant optical sensors of changes in the value of analyte refractive index. This research subject has recently invoked much attention due to development of novel fiber types, as well as due to development of techniques for the activation of fiber microstructure with functional materials. Particularly, we consider two sensors types. The first sensor type employs hollow core photonic bandgap fibers where core guided mode is confined in the analyte filled core through resonant effect in the surrounding periodic reflector. The second sensor type employs metalized microstructured or photonic bandgap waveguides and fibers, where core guided mode is phase matched with a plasmon propagating at the fiber/analyte interface. In resonant sensors one typically employs fibers with strongly nonuniform spectral transmission characteristics that are sensitive to changes in the real part of the analyte refractive index. Moreover, if narrow absorption lines are present in the analyte transmission spectrum, due to Kramers-Kronig relation this will also result in strong variation in the real part of the refractive index in the vicinity of an absorption line. Therefore, resonant sensors allow detection of minute changes both in the real part of the analyte refractive index (10−6–10−4 RIU, as well as in the imaginary part of the analyte refractive index in the vicinity of absorption lines. In the following we detail various resonant sensor implementations, modes of operation, as well as analysis of sensitivities for some of the common transduction mechanisms for bio- and chemical sensing applications. Sensor designs considered in this review span spectral operation regions from the visible to terahertz.

  3. Fiber optic and laser sensors VII; Proceedings of the Meeting, Boston, MA, Sept. 5-7, 1989

    Science.gov (United States)

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

    1990-01-01

    Various papers on fiber optic and laser sensors are presented. Individual topics addressed include: fiber optic photoelastic pressure sensor for high-temperature gases, fiber optic gyroscope using an eight-component LiNbO3 integrated optic circuit, design and performance of a fiber optic gyroscope using integrated optics, digital angular position sensor using wavelength division multiplexing, simple repeatable fiber optic intensity sensor for temperature measurement, compensation for effects of ambient temperature on rare-earth-doped fiber optic thermometer.

  4. A robust and reliable optical trace oxygen sensor

    Science.gov (United States)

    McDowell, G. R.; Holmes-Smith, A. S.; Uttamlal, M.; Mitchell, C.; Shannon, P. H.

    2017-05-01

    In applications of nitrogen (N2) generation, industrial gas manufacturing and food packaging there is a need to ensure oxygen (O2) is absent from the environment, even at the lowest concentration levels. Therefore, there has been an increased growth in the development of trace O2 parts per million (ppm) sensors over the past decade to detect and quantify the concentration of molecular O2 in the environment whether it be dissolved or gaseous O2. The majority of commercially available trace O2 sensors are based on electrochemical, zirconia and paramagnetic technologies. Here, the development of a luminescence-based optical trace O2 sensor is presented. Luminescence-based sensing is now regarded as one of the best techniques for the detection and quantification of O2. This is due to the high detection sensitivity, no O2 is consumed and there are a vast array of luminescent indicators and sensing platforms (polymers) that can be selected to suit the desired application. The sensor will be shown to operate from -30 °C to +60 °C in the 0-1000 ppm and/or 0-1200 μbar partial pressure of oxygen (ppO2) range and is equipped with temperature and pressure compensation. The luminescence non-depleting principle, sensor specifications and miniaturized nature offers an attractive alternative to other sensing technologies and advantages over other luminescence-based O2 ppm sensors.

  5. A fibre-optic oxygen sensor for monitoring human breathing.

    Science.gov (United States)

    Chen, Rongsheng; Formenti, Federico; Obeid, Andy; Hahn, Clive E W; Farmery, Andrew D

    2013-09-01

    The development and construction of a tapered-tip fibre-optic fluorescence based oxygen sensor is described. The sensor is suitable for fast and real-time monitoring of human breathing. The sensitivity and response time of the oxygen sensor were evaluated in vitro with a gas pressure chamber system, where oxygen partial pressure was rapidly changed between 5 and 15 kPa, and then in vivo in five healthy adult participants who synchronized their breathing to a metronome set at 10, 20, 30, 40, 50, and 60 breaths min(-1). A Datex Ultima medical gas analyser was used to monitor breathing rate as a comparator. The sensor's response time in vitro was less than 150 ms, which allows accurate continuous measurement of inspired and expired oxygen pressure. Measurements of breathing rate by means of our oxygen sensor and of the Datex Ultima were in strong agreement. The results demonstrate that the device can reliably resolve breathing rates up to 60 breaths min(-1), and that it is a suitable cost-effective alternative for monitoring breathing rates and end-tidal oxygen partial pressure in the clinical setting. The rapid response time of the sensor may allow its use for monitoring rapid breathing rates as occur in children and the newborn.

  6. Optical sensors for process control and emissions monitoring in industry

    Energy Technology Data Exchange (ETDEWEB)

    S. W. Alendorf; D. K. Ottensen; D. W. Hahn; T. J. Kulp; U. B. Goers

    1999-01-01

    Sandia National Laboratories has a number of ongoing projects developing optical sensors for industrial environments. Laser-based sensors can be attractive for relatively harsh environments where extractive sampling is difficult, inaccurate, or impractical. Tools developed primarily for laboratory research can often be adapted for the real world and applied to problems far from their original uses. Spectroscopic techniques, appropriately selected, have the potential to impact the bottom line of a number of industries and industrial processes. In this paper the authors discuss three such applications: a laser-based instrument for process control in steelmaking, a laser-induced breakdown method for hazardous metal detection in process streams, and a laser-based imaging sensor for evaluating surface cleanliness. Each has the potential to provide critical, process-related information in a real-time, continuous manner. These sensor techniques encompass process control applications and emissions monitoring for pollution prevention. They also span the range from a field-tested pre-commercial prototype to laboratory instrumentation. Finally, these sensors employ a wide range of sophistication in both the laser source and associated analytical spectroscopy. In the ultimate applications, however, many attributes of the sensors are in common, such as the need for robust operation and hardening for harsh industrial environments.

  7. Optical Sensors based on Raman Effects

    DEFF Research Database (Denmark)

    Jernshøj, Kit Drescher

    Formålet med denne afhandling er at give en systematisk og uddybende videnskabelig diskussion af molekylær Raman spredning, som kan danne grundlag for udviklingen af molekylespecifikke optiske sensorer til on-site, ikke-destruktiv måling. Afhandlingen falder i tre dele, to teoriafsnit, hvor første...... del omhandler den tilgangelige molekylære information ved overfladeforstærket resonans Raman spredning (SERRS), samt hvordan adgangen til denne information kan optimeres. Anden del omhandler, hvordan det molekylære informationsindhold kan forøges ved at kombinere polariserede Raman og resonans Raman...... målinger på frie molekyler med multivariat analyse. I tredje og sidste del, som er et eksperimentelt afsnit, præsenteres og diskuteres overfladeforstærkede Raman målinger (SERS) på tre udvalgte pesticider. Afhandlingen indledes med en diskussion af teorien bag SERRS med speciel fokus på den molekylære...

  8. In Situ Sensors for the Chemical Industry- Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Tate, J D; Knittel, Trevor

    2006-06-30

    minimized their applicability in the chemical industry. In order to take advantage of the promise of this technology a number of technology advances were required, within price limits for market acceptance. This project significantly advanced the state of TDL technology for application in chemical industry applications. With these advances a commercially available product now exists that has already achieved market success and is installed in critical applications. The ability to make fast, sensitive and accurate measurements inside the chemical processes is now delivering improved process control, energy efficiency and emissions control within the U.S. Chemical Industry. Despite the success we enjoyed for the laser-based sensors, there were significant technical barriers for the solid-state sensors. With exception of a generic close-coupled extractive housing and electronics interface, there were significant issues with all of the solid-state sensor devices we sought to develop and test. Ultimately, these issues were roadblocks that prevented further development and testing. The fundamental limitations of available sensor materials that we identified, formulated and tested were overwhelming. This situation forced our team to cancel these portions of the project and focus our resources on laser-based sensor techniques. The barriers of material compatibility, sensitivity, speed of response, chemical interferences, etc. are surmountable in the field of solid-state sensors. Inability to address any single one of these attributes will prevent wide-implementation into this market. This situation is plainly evident by the lack of such devices in the online analyzer market (for petrochemicals).

  9. Humidity insensitive step-index polymer optical fibre Bragg grating sensors

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Fasano, Andrea; Stefani, Alessio;

    2015-01-01

    We have fabricated and characterised a humidity insensitive step index(SI) polymer optical fibre(POF) Bragg grating sensors. The fibre was made based on the injection molding technique, which is an efficient method for fast, flexible and cost effective preparation of the fibre preform. The fabric......We have fabricated and characterised a humidity insensitive step index(SI) polymer optical fibre(POF) Bragg grating sensors. The fibre was made based on the injection molding technique, which is an efficient method for fast, flexible and cost effective preparation of the fibre preform....... The fabricated SIPOF has a core made from TOPAS with a glass transition temperature of 134 degrees C and a cladding from ZEONEX with a glass transition temperature of 138 degrees C. The main advantages of the proposed SIPOF are the low water absorption and good chemical resistance compared to the conventional...

  10. Optical fiber sensor having an active core

    Science.gov (United States)

    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.

  11. Multi-channel monolithic integrated optic fiber Bragg grating sensor interrogator

    Science.gov (United States)

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

    2011-09-01

    Fiber Bragg grating (FBG) is a mature sensing technology for the measurement of strain, vibration, acoustics, acceleration, pressure, temperature, moisture, and corrosion. It has gained rapid acceptance in civil, aerospace, chemical and petrochemical, medicine, aviation and automotive industries. The most prominent advantages of FBG are: small size and light weight, distributed array of FBG transducers on a single fiber, and immunity to radio frequency interference. However, a major disadvantage of FBG technology is that conventional state-of-the-art FBG interrogation system is typically bulky, heavy, and costly bench top instruments that are typically assembled from off-the-shelf fiber optic and optical components integrated with a signal electronics board into an instrument console. Based on the industrial need for a compact FBG interrogation system, this paper describes recent progress towards the development of miniature fiber Bragg grating sensor interrogator (FBG-Transceiver™) system based on multi-channel monolithic integrated optic sensor microchip technology. The integrated optic microchip technology enables monolithic integration of all functionalities, both passive and active, of conventional bench top FBG sensor interrogator system, packaged in a miniaturized, low power operation, 2 cm×5 cm small form factor (SFF) package suitable for long-term structural health monitoring in applications where size, weight, and power are critical for operation.

  12. Chemometrics review for chemical sensor development, task 7 report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-05-01

    This report, the seventh in a series on the evaluation of several chemical sensors for use in the U.S. Department of Energy`s (DOE`s) site characterization and monitoring programs, concentrates on the potential use of chemometrics techniques in analysis of sensor data. Chemometrics is the chemical discipline that uses mathematical, statistical, and other methods that employ formal logic to: design or select optimal measurement procedures and experiments and provide maximum relevant chemical information by analyzing chemical data. The report emphasizes the latter aspect. In a formal sense, two distinct phases are in chemometrics applications to analytical chemistry problems: (1) the exploratory data analysis phase and (2) the calibration and prediction phase. For use in real-world problems, it is wise to add a third aspect - the independent validation and verification phase. In practical applications, such as the ERWM work, and in order of decreasing difficulties, the most difficult tasks in chemometrics are: establishing the necessary infrastructure (to manage sampling records, data handling, and data storage and related aspects), exploring data analysis, and solving calibration problems, especially for nonlinear models. Chemometrics techniques are different for what are called zeroth-, first-, and second-order systems, and the details depend on the form of the assumed functional relationship between the measured response and the concentrations of components in mixtures. In general, linear relationships can be handled relatively easily, but nonlinear relationships can be difficult.

  13. Fiber optical Bragg grating sensors embedded in CFRP wires

    Science.gov (United States)

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

    1999-05-01

    Based on the example application of Emmenbridge, a newly built steel-concrete-composite bridge in Switzerland with 47 m long built-in carbon fiber reinforced polymer (CFRP) prestressing cables, we will present and analyze the process chain leading to a reliable surveillance of modern civil engineering structures with embedded fiber optical Bragg gratings. This consists first in the embedding of optical fibers and in-fiber Bragg gratings in long CFRP wires in an industrial environment, including fiber optical monitoring of the curing process. Then, various qualifying tests were done: annealing experiments for determining optical lifetime of the Bragg gratings used, dynamic and static tensile tests for estimating their mechanical lifetime under operation, push-out experiments to check adhesion of fiber/coating/matrix interfaces, and performance tests to determine strain and temperature sensitivity of the embedded Bragg gratings. Finally, the prestressing cables were equipped with the CFRP sensor wires and built into the bridge.

  14. Rockslide deformation monitoring with fiber optic strain sensors

    Directory of Open Access Journals (Sweden)

    J. R. Moore

    2010-02-01

    Full Text Available With micro-strain resolution and the capability to sample at rates of 100 Hz and higher, fiber optic (FO strain sensors offer exciting new possibilities for in-situ landslide monitoring. Here we describe a new FO monitoring system based on long-gauge fiber Bragg grating sensors installed at the Randa Rockslide Laboratory in southern Switzerland. The new FO monitoring system can detect sub-micrometer scale deformations in both triggered-dynamic and continuous measurements. Two types of sensors have been installed: (1 fully embedded borehole sensors and (2 surface extensometers. Dynamic measurements are triggered by sensor deformation and recorded at 100 Hz, while continuous data are logged every 5 min. Deformation time series for all sensors show displacements consistent with previous monitoring. Accelerated shortening following installation of the borehole sensors is likely related to long-term shrinkage of the grout. A number of transient signals have been observed, which in some cases were large enough to trigger rapid sampling. The combination of short- and long-term observation offers new insight into the deformation process. Accelerated surface crack opening in spring is shown to have a diurnal trend, which we attribute to the effect of snowmelt seeping into the crack void space and freezing at night to generate pressure on the crack walls. Controlled-source tests investigated the sensor response to dynamic inputs, which compared an independent measure of ground motion against the strain measured across a surface crack. Low frequency signals were comparable but the FO record suffered from aliasing, where undersampling of higher frequency signals generated spectral peaks not related to ground motion.

  15. Optical sensor array platform based on polymer electronic devices

    Science.gov (United States)

    Koetse, Marc M.; Rensing, Peter A.; Sharpe, Ruben B. A.; van Heck, Gert T.; Allard, Bart A. M.; Meulendijks, Nicole N. M. M.; Kruijt, Peter G. M.; Tijdink, Marcel W. W. J.; De Zwart, René M.; Houben, René J.; Enting, Erik; van Veen, Sjaak J. J. F.; Schoo, Herman F. M.

    2007-10-01

    Monitoring of personal wellbeing and optimizing human performance are areas where sensors have only begun to be used. One of the reasons for this is the specific demands that these application areas put on the underlying technology and system properties. In many cases these sensors will be integrated in clothing, be worn on the skin, or may even be placed inside the body. This implies that flexibility and wearability of the systems is essential for their success. Devices based on polymer semiconductors allow for these demands since they can be fabricated with thin film technology. The use of thin film device technology allows for the fabrication of very thin sensors (e.g. integrated in food product packaging), flexible or bendable sensors in wearables, large area/distributed sensors, and intrinsically low-cost applications in disposable products. With thin film device technology a high level of integration can be achieved with parts that analyze signals, process and store data, and interact over a network. Integration of all these functions will inherently lead to better cost/performance ratios, especially if printing and other standard polymer technology such as high precision moulding is applied for the fabrication. In this paper we present an optical transmission sensor array based on polymer semiconductor devices made by thin film technology. The organic devices, light emitting diodes, photodiodes and selective medium chip, are integrated with classic electronic components. Together they form a versatile sensor platform that allows for the quantitative measurement of 100 channels and communicates wireless with a computer. The emphasis is given to the sensor principle, the design, fabrication technology and integration of the thin film devices.

  16. Soil chemical sensor and precision agricultural chemical delivery system and method

    Energy Technology Data Exchange (ETDEWEB)

    Colburn, J.W. Jr.

    1991-07-23

    A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil. The appropriate concentration is then found and the servo-controlled delivery system applies the appropriate amount of fertilizer or agricultural chemicals substantially in the location from which the soil measurement was taken. 5 figures.

  17. Initial Photophysical Characterization of the Proteorhodopsin Optical Proton Sensor (PROPS

    Directory of Open Access Journals (Sweden)

    Jay eNadeau

    2015-09-01

    Full Text Available Fluorescence is not frequently used as a tool for investigating the photocycles of rhodopsins, largely because of the low quantum yield of the retinal chromophore. However, a new class of genetically encoded voltage sensors is based upon rhodopsins and their fluorescence. The first such sensor reported in the literature was the proteorhodopsin optical proton sensor (PROPS, which is capable of indicating membrane voltage changes in bacteria by means of changes in fluorescence. However, the properties of this fluorescence, such as its lifetime decay components and its origin in the protein photocycle, remain unknown. This paper reports steady-state and nanoscale time-resolved emission of this protein expressed in two strains of Escherichia coli, before and after membrane depolarization. The voltage-dependence of a particularly long lifetime component is established. Additional work to improve quantum yields and improve the general utility of PROPS is suggested.

  18. Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors

    Directory of Open Access Journals (Sweden)

    Kamalakanta Behera

    2015-12-01

    Full Text Available Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability, ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO2 gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO2 sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review.

  19. Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors.

    Science.gov (United States)

    Behera, Kamalakanta; Pandey, Shubha; Kadyan, Anu; Pandey, Siddharth

    2015-12-04

    Due to their unusual physicochemical properties (e.g., high thermal stability, low volatility, high intrinsic conductivity, wide electrochemical windows and good solvating ability), ionic liquids have shown immense application potential in many research areas. Applications of ionic liquid in developing various sensors, especially for the sensing of biomolecules, such as nucleic acids, proteins and enzymes, gas sensing and sensing of various important ions, among other chemosensing platforms, are currently being explored by researchers worldwide. The use of ionic liquids for the detection of carbon dioxide (CO₂) gas is currently a major topic of research due to the associated importance of this gas with daily human life. This review focuses on the application of ionic liquids in optical and electrochemical CO₂ sensors. The design, mechanism, sensitivity and detection limit of each type of sensor are highlighted in this review.

  20. Advanced optical position sensors for magnetically suspended wind tunnel models

    Science.gov (United States)

    Lafleur, S.

    1985-01-01

    A major concern to aerodynamicists has been the corruption of wind tunnel test data by model support structures, such as stings or struts. A technique for magnetically suspending wind tunnel models was considered by Tournier and Laurenceau (1957) in order to overcome this problem. This technique is now implemented with the aid of a Large Magnetic Suspension and Balance System (LMSBS) and advanced position sensors for measuring model attitude and position within the test section. Two different optical position sensors are discussed, taking into account a device based on the use of linear CCD arrays, and a device utilizing area CID cameras. Current techniques in image processing have been employed to develop target tracking algorithms capable of subpixel resolution for the sensors. The algorithms are discussed in detail, and some preliminary test results are reported.

  1. DFB laser based electrical dynamic interrogation for optical fiber sensors

    Science.gov (United States)

    Carvalho, J. P.; Frazão, O.; Baptista, J. M.; Santos, J. L.; Barbero, A. P.

    2012-04-01

    An electrical dynamic interrogation technique previously reported by the authors for long-period grating sensors is now progressed by relying its operation exclusively on the modulation of a DFB Laser. The analysis of the detected first and second harmonic generated by the electrical modulation of the DFB Laser allows generating an optical signal proportional to the LPG spectral shift and resilient to optical power fluctuations along the system. This concept permits attenuating the effect of the 1/f noise of the photodetection, amplification and processing electronics on the sensing head resolution. This technique is employed in a multiplexing sensing scheme that measures refractive index variations.

  2. Optical fiber sensor for tracking line-focus solar collectors.

    Science.gov (United States)

    Wiczer, J J

    1982-08-01

    Currently there is a need to provide an alignment monitor feedback signal to the tracking mechanism of line-focus trough-type concentrating solar collectors. We report here on the novel use of an optical fiber as a distributed integrating sensor to generate such a signal. Experiments have shown that 3.0 m of optical fiber exposed to concentrated sunlight equal to ~40 suns in intensity will generate 1 microA of signal current in a silicon photodiode. These data were measured in an experimental line-focus solar collector using solar flux conditions common to this type of collector.

  3. An Optical Fiber Sensor for Electrification Measurement in Power Transformers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Static electrification and partial discharges caused by oil flow in power transformers lead to many accidents. In this paper, an optical fiber sensor which can be directly mounted inside high-voltage electric devices for electrification measurement in power transformers is introduced. Unlike the existing normal electrification measurement methods which only be used in static oil, the new one takes optical fiber as its probe and measures the electrification in flowing oil by detecting luminous flux, and is available for on-line monitoring.

  4. Integrated optical read-out for polymeric cantilever-based sensors

    DEFF Research Database (Denmark)

    Tenje, Maria

    2007-01-01

    This thesis presents a novel read-out method developed for cantilever-based sensors. Cantilevers are thin beams clamped at one end and during the last 10 years they have emerged as an interesting new type of bio/chemical sensor. The specific recognition of a chemical manifests itself as a bending...... Young’s modulus instead of the conventional materials Si and Si3N4. Here, a novel read-out method is presented where optical waveguides are used to integrate the light into the cantilever. It is an all-polymer device where both the cantilever and the waveguides are fabricated in the negative resist SU-8....... Waveguides are structured on either side of the cantilever that is free-hanging in a microfluidic channel. Light is guided into the system and is either transmitted through the cantilever or reflected off the cantilever front-end, depending on the mode of operation. This work shows that waveguides, only...

  5. Adaptive optical design in surface plasma resonance sensor

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; ZHONG Jin-gang

    2006-01-01

    A double-prism adaptive optical design in surface plasma resonance (SPR) sensor is proposed,which consists of two identical isosceles right-triangular prisms. One prism is used as a component of Kretschmann configuration,and the other is for regulation of the optical path. When double-prism structure is angle-scanned by an immovable incident ray,the output ray will be always parallel with the incident ray and just has a small displacement with the shift of output point.The output ray can be focused on a fixed photodetector by a convex lens.Thus it can be avoided that a prism and a photodetector rotate by θ and 2θ respectively in conventional angular scanning SPR sensor.This new design reduces the number of the movable components,makes the structure simple and compact,and makes the manipulation convenient.

  6. Automatic Laser Glare Suppression in Electro-Optical Sensors

    Directory of Open Access Journals (Sweden)

    Gunnar Ritt

    2015-01-01

    Full Text Available Progress in laser technology has led to very compact but nevertheless powerful laser sources. In the visible and near infrared spectral region, lasers of any wavelength can be purchased. Continuous wave laser sources pose an especially serious threat to the human eye and electro-optical sensors due to their high proliferation and easy availability. The manifold of available wavelengths cannot be covered by conventional safety measures like absorption or interference filters. We present a protection concept for electro-optical sensors to suppress dazzling in the visible spectral region. The key element of the concept is the use of a digital micromirror device (DMD in combination with wavelength multiplexing. This approach allows selective spectral filtering in defined regions of interest in the scene. The system offers the possibility of automatic attenuation of dazzling laser radiation.

  7. An Optical Fibre-Based Sensor for Respiratory Monitoring

    Directory of Open Access Journals (Sweden)

    Marek Krehel

    2014-07-01

    Full Text Available In this paper, a textile-based respiratory sensing system is presented. Highly flexible polymeric optical fibres (POFs that react to applied pressure were integrated into a carrier fabric to form a wearable sensing system. After the evaluation of different optical fibres, different setups were compared. To demonstrate the feasibility of such a wearable sensor, the setup featuring the best performance was placed on the human torso, and thus it was possible to measure the respiratory rate. Furthermore, we show that such a wearable system enables to keep track of the way of breathing (diaphragmatic, upper costal and mixed when the sensor is placed at different positions of the torso. A comparison of the results with the output of some commercial respiratory measurements devices confirmed the utility of such a monitoring device.

  8. Optical Electronic Bragg Reflection Sensor System with Hydrodynamic Flow Applications

    Science.gov (United States)

    Lyons, D. R.

    2003-01-01

    This project, as described in the following report, involved design and fabrication of fiber optic sensors for the detection and measurement of dynamic fluid density variations. These devices are created using UV (ultraviolet) ablation and generally modified transverse holographic fiber grating techniques. The resulting phase gratings created on or immediately underneath the flat portion of D-shaped optical waveguides are characterized as evanescent field sensing devices. The primary applications include the sensor portion of a real-time localized or distributed measurement system for hydrodynamic flow, fluid density measurements, and phase change phenomena. Several design modifications were implemented in an attempt to accomplish the tasks specified in our original proposal. In addition, we have established key collaborative relationships with numerous people and institutions.

  9. Development of an optical fiber sensor for angular displacement measurements.

    Science.gov (United States)

    Jung, Gu-In; Kim, Ji-Sun; Lee, Tae-Hee; Choi, Ju-Hyeon; Oh, Han-Byeol; Kim, A-Hee; Eom, Gwang-Moon; Lee, Jeong-Hwan; Chung, Soon-Cheol; Park, Jong-Rak; Lee, Young-Jae; Park, Hee-Jung; Jun, Jae-Hoon

    2014-01-01

    For diagnostic and therapeutic purposes, the joint angle measurement of a patient after an accident or a surgical operation is significant for monitoring and evaluating the recovering process. This paper proposed an optical fiber sensor for the measurement of angular displacement. The effect of beveled fiber angle on the detected light signal was investigated to find an appropriate mathematical model. Beveled fiber tips redirected the light over a range of angles away from the fiber axis. Inverse polynomial models were applied to directly obtain and display the joint angle change in real time with the Lab-VIEW program. The actual joint angle correlated well with the calculated LabVIEW output angle over the test range. The proposed optical sensor is simple, cost effective, small in size, and can evaluate the joint angle in real time. This method is expected to be useful in the field of rehabilitation and sport science.

  10. Smart aircraft composite structures with embedded small-diameter optical fiber sensors

    Science.gov (United States)

    Takeda, Nobuo; Minakuchi, Shu

    2012-02-01

    This talk describes the embedded optical fiber sensor systems for smart aircraft composite structures. First, a summary of the current Japanese national project on structural integrity diagnosis of aircraft composite structures is described with special emphasis on the use of embedded small-diameter optical fiber sensors including FBG sensors. Then, some examples of life-cycle monitoring of aircraft composite structures are presented using embedded small-diameter optical fiber sensors for low-cost and reliable manufacturing merits.

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

    Energy Technology Data Exchange (ETDEWEB)

    A. Wang; H. Xiao; R. May

    1999-10-29

    Efficient and complete recovery of petroleum reserves from existing oil wells has proven difficult due to a lack of robust instrumentation that can 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 multi-lateral wells. The main objective of the research program is to develop cost-effective, reliable fiber sensor instrumentation for real-time monitoring and /or control of various key parameters crucial to efficient and economical oil production. This report presents the detailed research work and technical progress from October 1, 1998 to September 30, 1999. The research performed over the first year of the program has followed the schedule as proposed, and solid research progress has been made in specification of the technical requirements, design and fabrication of the SCIIB sensor probes, development of the sensor systems, development of DSP-based signal processing techniques, and construction of the test systems. These technical achievements will significantly help to advance continued research on sensor tests and evaluation during the second year of the program.

  12. Optical fiber sensor based on surface plasmon resonance for rapid detection of avian influenza virus subtype H6: Initial studies.

    Science.gov (United States)

    Zhao, Xihong; Tsao, Yu-Chia; Lee, Fu-Jung; Tsai, Woo-Hu; Wang, Ching-Ho; Chuang, Tsung-Liang; Wu, Mu-Shiang; Lin, Chii-Wann

    2016-07-01

    A side-polished fiber optic surface plasmon resonance (SPR) sensor was fabricated to expose the core surface and then deposited with a 40 nm thin gold film for the near surface sensing of effective refractive index changes with surface concentration or thickness of captured avian influenza virus subtype H6. The detection surface of the SPR optical fiber sensor was prepared through the plasma modification method for binding a self-assembled monolayer of isopropanol chemically on the gold surface of the optical fiber. Subsequently, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide was activated to enable EB2-B3 monoclonal antibodies to capture A/chicken/Taiwan/2838V/00 (H6N1) through a flow injection system. The detection limit of the fabricated optical fiber sensor for A/chicken/Taiwan/2838V/00 was 5.14 × 10(5) EID50/0.1 mL, and the response time was 10 min on average. Moreover, the fiber optic sensor has the advantages of a compact size and low cost, thus rendering it suitable for online and remote sensing. The results indicated that the optical fiber sensor can be used for epidemiological surveillance and diagnosing of avian influenza subtype H6 rapidly.

  13. Hazard monitoring in mines using fibre optic sensors

    Science.gov (United States)

    Liu, T.; Wang, C.; Wei, Y.; Zhao, Y.; Huo, D.; Shang, Y.; Wang, Z.; Ning, Y.

    2009-10-01

    We report the development of a comprehensive safety monitoring solution for coal mines. A number of fibre optic sensors have been developed and deployed for safety monitoring of mine roof integrity and hazardous gases. The FOS-based mine hazard detection system offers unique advantages of intrinsic safety, multi-location and multi-parameter monitoring. They can be potentially used to build expert systems for mine hazard early detection and prevention.

  14. Research of optical rainfall sensor based on CCD linear array

    Institute of Scientific and Technical Information of China (English)

    YANG; Bifeng; LIU; Yuyan; LU; Ying; WU; Shangqian

    2015-01-01

    Rainfall monitoring is one of the most important meteorological observation elements for the disaster weather. The maintenance of current tipping bucket rain gauge and weighing type rain gauge is a critical issue. The optical rainfall sensor based on CCD linear array is mainly studied in this paper. Because of the maintenance-free time and good adaptability,it can be widely used in the automatic rainfall monitoring in severe environment and have a good perspective in using.

  15. Optical Oxygen Sensors for Applications in Microfluidic Cell Culture

    Directory of Open Access Journals (Sweden)

    Samantha M. Grist

    2010-10-01

    Full Text Available The presence and concentration of oxygen in biological systems has a large impact on the behavior and viability of many types of cells, including the differentiation of stem cells or the growth of tumor cells. As a result, the integration of oxygen sensors within cell culture environments presents a powerful tool for quantifying the effects of oxygen concentrations on cell behavior, cell viability, and drug effectiveness. Because microfluidic cell culture environments are a promising alternative to traditional cell culture platforms, there is recent interest in integrating oxygen-sensing mechanisms with microfluidics for cell culture applications. Optical, luminescence-based oxygen sensors, in particular, show great promise in their ability to be integrated with microfluidics and cell culture systems. These sensors can be highly sensitive and do not consume oxygen or generate toxic byproducts in their sensing process. This paper presents a review of previously proposed optical oxygen sensor types, materials and formats most applicable to microfluidic cell culture, and analyzes their suitability for this and other in vitro applications.

  16. Interferometric and localized surface plasmon based fiber optic sensor

    Science.gov (United States)

    Muri, Harald Ian D. I.; Bano, Andon; Hjelme, Dag Roar

    2017-02-01

    We demonstrate a novel single point, multi-parameter, fiber optic sensor concept based on a combination of interferometric and plasmonic sensor modalities on an optical fiber end face. The sensor consists of a micro-Fabry-Perot interferometer in the form of a hemispherical stimuli-responsive hydrogel with immobilized gold nanoparticles. We present results of proof-of-concept experiments demonstrating local surface plasmon resonance (LSPR) sensing of refractive index (RI) in the visible range and interferometric measurements of volumetric changes of the pH stimuli-responsive hydrogel in near infrared range. The response of LSPR to RI (Δλr/ΔRI 877nm/RI) and the free spectral range (FSR) to pH (ΔpH/ΔFSR = 0.09624/nm) were measured with LSPR relatively constant for hydrogel swelling degree and FSR relatively constant for RI. We expect this novel sensor concept to be of great value for biosensors for medical applications.

  17. High-temperature sapphire optical sensor fiber coatings

    Science.gov (United States)

    Desu, Seshu B.; Claus, Richard O.; Raheem, Ruby; Murphy, Kent A.

    1990-10-01

    the filter. These modes may be attributed to a number of material degradation mechanisms, such as thermal shock, oxidation corrosion of the material, mechanical loads, or phase changes in the filter material. Development of high temperature optical fiber (sapphire) sensors embedded in the CXF filters would be very valuable for both monitoring the integrity of the filter during its use and understanding the mechanisms of degradation such that durable filter development will be facilitated. Since the filter operating environment is very harsh, the high temperature sapphire optical fibers need to be protected and for some sensing techniques the fiber must also be coated with low refractive index film (cladding). The objective of the present study is to identify materials and develop process technologies for the application of claddings and protective coatings that are stable and compatible with sapphire fibers at both high temperatures and pressures.

  18. Optically Powered Temperature Sensor with Optical Fiber Ling①

    Institute of Scientific and Technical Information of China (English)

    YUZhijing; WANGYutian

    1997-01-01

    The principle of a new optical fiber temperature transducer is presented,and ingenious design scheme of this transducer is given.Because taking the special modulation and ratio measurement,this new transducer has provided with high characteristics:experimental transmitting distance is 500m;measurement error,in the measured temperature range of 0-250℃,,is less than ±0.5℃;power consumption of the probe is less than 300μW.Finally,some points of the experiment are given.

  19. Distributed acoustic fibre optic sensors for condition monitoring of pipelines

    Science.gov (United States)

    Hussels, Maria-Teresa; Chruscicki, Sebastian; Habib, Abdelkarim; Krebber, Katerina

    2016-05-01

    Industrial piping systems are particularly relevant to public safety and the continuous availability of infrastructure. However, condition monitoring systems based on many discrete sensors are generally not well-suited for widespread piping systems due to considerable installation effort, while use of distributed fibre-optic sensors would reduce this effort to a minimum. Specifically distributed acoustic sensing (DAS) is employed for detection of third-party threats and leaks in oil and gas pipelines in recent years and can in principle also be applied to industrial plants. Further possible detection routes amenable by DAS that could identify damage prior to emission of medium are subject of a current project at BAM, which aims at qualifying distributed fibre optic methods such as DAS as a means for spatially continuous monitoring of industrial piping systems. Here, first tests on a short pipe are presented, where optical fibres were applied directly to the surface. An artificial signal was used to define suitable parameters of the measurement system and compare different ways of applying the sensor.

  20. Curvature optical fiber sensor by using bend enhanced method

    Institute of Scientific and Technical Information of China (English)

    Jianrong ZHANG; Hairong LIU; Xinkun WU

    2009-01-01

    Deflection curvature measurement can offer a number of advantages compared with the well-established strain measurement alternative. It is able to measure thin structure; fiber has no resistance with force, which leads to a high precision. There are many kinds of curvature gauges with different operation principles. A low-cost curvature optical fiber sensor using bend enhanced method to improve its curvature measurement sensitivity was devel-oped in recent years. This sensor can distinguish between convex bending and concave bending and has a good linearity in measuring large curvature deformation. Whisper gallery ray theory and Monte Carlo simulation are new achievements by computer experiment. The operation mechanism of this curvature optical fiber sensor is presented based on light scattering theory. The attenuation is ascribed to the transmission mode changing by the curvature of the fiber, which affects the attenuation of the surface scattering. The mathematical model of relationship among light loss, bending curvature, surface roughness, and parameters of the fiber's configuration is also presented. We design different kinds of shapes of sensitive zones; each zone has different parameters. Through detecting their output optical attenuations in different curvatures and fitting the results by exponential decaying functions, the proposed model is demonstrated by experimental results. Also, we compare the experi-mental results with the theoretical analysis and discuss the sensitivity dependence on bending direction.