Alcohol sensor based on u-bent hetero-structured fiber optic

Science.gov (United States)

Patrialova, Sefi N.; Hatta, Agus M.; Sekartedjo, Sekartedjo

2016-11-01

A sensor based on a fiber optic hetero-structure to determine the concentration of alcohol has been proposed. The structure of the sensing probe in this research is a singlemode-multimode-singlemode (SMS) which bent into Ushaped and soon called as SMS u-bent. The SMS structure was chosen to get a higher sensitivity. This research utilizes the principle of multimode interference and evanescent field by modifying the cladding with various alcohol concentration. Testing of the sensor's performance has been done by measuring the sensor's power output response to the length of the SMS fiber optic, bending diameter, and alcohol concentration. Based on the experiment result, the ubent SMS fiber optic with 50 mm bending diameter and 63 mm MMF lenght has the highest sensitivity, 3.87 dB/% and the minimum resolution, 0.26 x 10-3 %.

Chemical Sensors Based on Optical Ring Resonators

Science.gov (United States)

Homer, Margie; Manfreda, Allison; Mansour, Kamjou; Lin, Ying; Ksendzov, Alexander

2005-01-01

Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong evanescent-wave coupling between the outer polymer layer and the electromagnetic field propagating along the waveguide core. By virtue of this coupling, the chemically induced change in index of refraction of the polymer causes a measurable shift in the resonance peaks of the ring. In a prototype that has been used to demonstrate the feasibility of this sensor concept, the ring resonator is a dielectric optical waveguide laid out along a closed path resembling a racetrack (see Figure 1). The prototype was fabricated on a silicon substrate by use of standard techniques of thermal oxidation, chemical vapor deposition, photolithography, etching, and spin coating. The prototype resonator waveguide features an inner cladding of SiO2, a core of SixNy, and a chemical-sensing outer cladding of ethyl cellulose. In addition to the ring Chemical sensors based on optical ring resonators are undergoing development. A ring resonator according to this concept is a closed-circuit dielectric optical waveguide. The outermost layer of this waveguide, analogous to the optical cladding layer on an optical fiber, is a made of a polymer that (1) has an index of refraction lower than that of the waveguide core and (2) absorbs chemicals from the surrounding air. The index of refraction of the polymer changes with the concentration of absorbed chemical( s). The resonator is designed to operate with relatively strong

Integrated optical readout for miniaturization of cantilever-based sensor system

DEFF Research Database (Denmark)

Nordström, Maria; Zauner, Dan; Calleja, Montserrat

2007-01-01

The authors present the fabrication and characterization of an integrated optical readout scheme based on single-mode waveguides for cantilever-based sensors. The cantilever bending is read out by monitoring changes in the optical intensity of light transmitted through the cantilever that also acts...

Optical Fibre Temperature Sensor Based On A Blackbody Radiation

Science.gov (United States)

Hypszer, Ryszard; Plucinski, Jerzy; Wierzba, Henryk J.

1990-01-01

The principle of operation of the fibre optical temperature sensor based on a blackbody radiation and its construction model is given in the paper. A quartz rod of 0.6 mm diameter and 20 cm length with a blackbody cavity at the one end was used to construct the sensor. The cavity was made by vacuum evaporation of a chromium layer and a silicone monooxide layer was used as a protection. Infrared radiation is transmitted by the fibre optic to the detection circuit. This sensor enables temperature measurement from 400 to 1200°C. The range of measurement is determined by the detection sensitivity and by rod softening. The resolution is of the order of 10-2°C. The sensor calibration was done by using PtRh1O-Pt thermocouple.

Structural health monitoring system of soccer arena based on optical sensors

Science.gov (United States)

Shishkin, Victor V.; Churin, Alexey E.; Kharenko, Denis S.; Zheleznova, Maria A.; Shelemba, Ivan S.

2014-05-01

A structural health monitoring system based on optical sensors has been developed and installed on the indoor soccer arena "Zarya" in Novosibirsk. The system integrates 119 fiber optic sensors: 85 strain, 32 temperature and 2 displacement sensors. In addition, total station is used for measuring displacement in 45 control points. All of the constituents of the supporting structure are subjects for monitoring: long-span frames with under floor ties, connections, purlins and foundation.

Graphene Oxide in Lossy Mode Resonance-Based Optical Fiber Sensors for Ethanol Detection

Directory of Open Access Journals (Sweden)

Miguel Hernaez

2017-12-01

Full Text Available The influence of graphene oxide (GO over the features of an optical fiber ethanol sensor based on lossy mode resonances (LMR has been studied in this work. Four different sensors were built with this aim, each comprising a multimode optical fiber core fragment coated with a SnO2 thin film. Layer by layer (LbL coatings made of 1, 2 and 4 bilayers of polyethyleneimine (PEI and graphene oxide were deposited onto three of these devices and their behavior as aqueous ethanol sensors was characterized and compared with the sensor without GO. The sensors with GO showed much better performance with a maximum sensitivity enhancement of 176% with respect to the sensor without GO. To our knowledge, this is the first time that GO has been used to make an optical fiber sensor based on LMR.

Graphene Oxide in Lossy Mode Resonance-Based Optical Fiber Sensors for Ethanol Detection.

Science.gov (United States)

Hernaez, Miguel; Mayes, Andrew G; Melendi-Espina, Sonia

2017-12-27

The influence of graphene oxide (GO) over the features of an optical fiber ethanol sensor based on lossy mode resonances (LMR) has been studied in this work. Four different sensors were built with this aim, each comprising a multimode optical fiber core fragment coated with a SnO₂ thin film. Layer by layer (LbL) coatings made of 1, 2 and 4 bilayers of polyethyleneimine (PEI) and graphene oxide were deposited onto three of these devices and their behavior as aqueous ethanol sensors was characterized and compared with the sensor without GO. The sensors with GO showed much better performance with a maximum sensitivity enhancement of 176% with respect to the sensor without GO. To our knowledge, this is the first time that GO has been used to make an optical fiber sensor based on LMR.

Characteristic Analysis Light Intensity Sensor Based On Plastic Optical Fiber At Various Configuration

Science.gov (United States)

Arifin, A.; Lusiana; Yunus, Muhammad; Dewang, Syamsir

2018-03-01

This research discusses the light intensity sensor based on plastic optical fiber. This light intensity sensor is made of plastic optical fiber consisting of two types, namely which is cladding and without cladding. Plastic optical fiber used multi-mode step-index type made of polymethyl metacrylate (PMMA). The infrared LED emits light into the optical fiber of the plastic and is subsequently received by the phototransistor to be converted to an electric voltage. The sensor configuration is made with three models: straight configuration, U configuration and gamma configuration with cladding and without cladding. The measured light source uses a 30 Watt high power LED with a light intensity of 0 to 10 Klux. The measured light intensity will affect the propagation of light inside the optical fiber sensor. The greater the intensity of the measured light, the greater the output voltage that is read on the computer. The results showed that the best optical fiber sensor characteristics were obtained in U configuration. Sensors with U-configuration without cladding had the best sensitivity and resolution values of 0.0307 volts/Klux and 0.0326 Klux. The advantages of this measuring light intensity based on the plastic optical fiber instrument are simple, easy-to-make operational systems, low cost, high sensitivity and resolution.

Flexible optical fiber sensor based on polyurethane

DEFF Research Database (Denmark)

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

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

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.

A Novel Optical Sensor Platform Designed for Wireless Sensor Networks

International Nuclear Information System (INIS)

Yang, Shuo; Zhou, Bochao; Sun, Tong; Grattan, Kenneth T V

2013-01-01

This paper presents a novel design of an optical sensor platform, enabling effective integration of a number of optical fibre ('wired') sensors with wireless sensor networks (WSNs). In this work, a fibre Bragg grating-based temperature sensor with low power consumption is specially designed as a sensing module and integrated successfully into a WSN, making full use of the advantages arising from both the advanced optical sensor designs and the powerful network functionalities resident in WSNs. The platform is expected to make an important impact on many applications, where either the conventional optical sensor designs or WSNs alone cannot meet the requirements.

Development of Laser LEDs Based a Programmable Optical Sensor for Detection of Environmental Pollutants

Directory of Open Access Journals (Sweden)

Amit K. Sharma

2009-01-01

Full Text Available The laser LED based optical sensor and its multifunctional operation for detection of environmental pollutants are described. The work will provide the instructions to design of circuitry for optical sensor instrument with a program based on a microcontroller (8902051-24PI, and to allow this program to communicate via RS-232 with computer. An algorithm is outlined by which the sensor instrument can use three laser LEDs (blue, Green and red to quantify the composition of pollutant. The operation of measurement through optical sensor has been applied to the study of detection and rate of reaction of pollutant i.e. methyl parathion and the produced informative data were also correlated with UV-vis spectrophotometry for the validation of results. The purpose of designed optical sensor is that the sophisticated analytical techniques show costly impact, time taking process, high consumable solvents and not suit for field application purpose which focuses the merits of the optical sensor.

Electrochemical and optical sugar sensors based on phenylboronic acid and its derivatives

Energy Technology Data Exchange (ETDEWEB)

Egawa, Yuya; Seki, Toshinobu [Faculty of Pharmaceutical Sciences, Josai University, Keyakidai, Sakado, Saitama 350-0295 (Japan); Takahashi, Shigehiro [Graduate School of Pharmaceutical Sciecnes, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Anzai, Jun-ichi, E-mail: junanzai@mail.pharm.tohoku.ac.jp [Graduate School of Pharmaceutical Sciecnes, Tohoku University, Aramaki, Aoba-ku, Sendai 980-8578 (Japan)

2011-10-10

Recent progress in electrochemical and optical sugar sensors based on phenylboronic acid (PBA) and its derivatives as recognition components is reviewed. PBAs are known to bind diol compounds including sugars to form cyclic boronate esters that are negatively charged as a result of the addition of OH{sup -} ions from solution. Based on the formation of PBA charged species, sugars and their derivatives can be detected by means of electrochemical and optical techniques. For the development of PBA-based electrochemical sensing systems or sensors, PBA is modified with a redox-active marker, because PBA itself is electrochemically inactive, and ferrocene derivatives are often employed for this purpose. Ferrocene-modified PBAs have been used as redox-active additives in solution for the electrochemical detection of sugars and derivatives. PBA-modified electrodes have also been constructed as reagentless electrochemical sensors, where PBAs are immobilized on the surface of metal and carbon electrodes through mainly two routes: as a self-assembled monolayer film and as a polymer thin film. PBA-modified electrodes can be successfully used to detect sugars and derivatives through potentiometric and voltammetric responses. In addition, PBA-modified electrodes can be used for the immobilization of glycoenzymes on an electrode surface by the formation of boronate esters with carbohydrate chains in the glycoenzymes, thus resulting in enzyme biosensors. For the development of PBA-based optical sensors, a variety of chromophores and fluorophores have been coupled with PBA. Azobenzene dyes have been most frequently used for the preparation of colorimetric sugar sensors, in which the absorption wavelength and intensity of the dye are dependent on the type and concentration of added sugars. The sensitivity of the sensors is significantly improved based on multi-component systems in which alizalin red S, pyrocatechol violet, starch-iodine complex, and cyclodextrin are employed as

Electrochemical and optical sugar sensors based on phenylboronic acid and its derivatives

International Nuclear Information System (INIS)

Egawa, Yuya; Seki, Toshinobu; Takahashi, Shigehiro; Anzai, Jun-ichi

2011-01-01

Recent progress in electrochemical and optical sugar sensors based on phenylboronic acid (PBA) and its derivatives as recognition components is reviewed. PBAs are known to bind diol compounds including sugars to form cyclic boronate esters that are negatively charged as a result of the addition of OH - ions from solution. Based on the formation of PBA charged species, sugars and their derivatives can be detected by means of electrochemical and optical techniques. For the development of PBA-based electrochemical sensing systems or sensors, PBA is modified with a redox-active marker, because PBA itself is electrochemically inactive, and ferrocene derivatives are often employed for this purpose. Ferrocene-modified PBAs have been used as redox-active additives in solution for the electrochemical detection of sugars and derivatives. PBA-modified electrodes have also been constructed as reagentless electrochemical sensors, where PBAs are immobilized on the surface of metal and carbon electrodes through mainly two routes: as a self-assembled monolayer film and as a polymer thin film. PBA-modified electrodes can be successfully used to detect sugars and derivatives through potentiometric and voltammetric responses. In addition, PBA-modified electrodes can be used for the immobilization of glycoenzymes on an electrode surface by the formation of boronate esters with carbohydrate chains in the glycoenzymes, thus resulting in enzyme biosensors. For the development of PBA-based optical sensors, a variety of chromophores and fluorophores have been coupled with PBA. Azobenzene dyes have been most frequently used for the preparation of colorimetric sugar sensors, in which the absorption wavelength and intensity of the dye are dependent on the type and concentration of added sugars. The sensitivity of the sensors is significantly improved based on multi-component systems in which alizalin red S, pyrocatechol violet, starch-iodine complex, and cyclodextrin are employed as

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....

Ambient light-based optical biosensing platform with smartphone-embedded illumination sensor.

Science.gov (United States)

Park, Yoo Min; Han, Yong Duk; Chun, Hyeong Jin; Yoon, Hyun C

2017-07-15

We present a hand-held optical biosensing system utilizing a smartphone-embedded illumination sensor that is integrated with immunoblotting assay method. The smartphone-embedded illumination sensor is regarded as an alternative optical receiver that can replaces the conventional optical analysis apparatus because the illumination sensor can respond to the ambient light in a wide range of wavelengths, including visible and infrared. To demonstrate the biosensing applicability of our system employing the enzyme-mediated immunoblotting and accompanying light interference, various types of ambient light conditions including outdoor sunlight and indoor fluorescent were tested. For the immunoblotting assay, the biosensing channel generating insoluble precipitates as an end product of the enzymatic reaction is fabricated and mounted on the illumination sensor of the smartphone. The intensity of penetrating light arrives on the illumination sensor is inversely proportional to the amount of precipitates produced in the channel, and these changes are immediately analyzed and quantified via smartphone software. In this study, urinary C-terminal telopeptide fragment of type II collagen (uCTX-II), a biomarker of osteoarthritis diagnosis, was tested as a model analyte. The developed smartphone-based sensing system efficiently measured uCTX-II in the 0-5ng/mL concentration range with a high sensitivity and accuracy under various light conditions. These assay results show that the illumination sensor-based optical biosensor is suitable for point-of-care testing (POCT). Copyright © 2016 Elsevier B.V. All rights reserved.

A Polymer Optical Fiber Temperature Sensor Based on Material Features.

Science.gov (United States)

Leal-Junior, Arnaldo; Frizera-Netoc, Anselmo; Marques, Carlos; Pontes, Maria José

2018-01-19

This paper presents a polymer optical fiber (POF)-based temperature sensor. The operation principle of the sensor is the variation in the POF mechanical properties with the temperature variation. Such mechanical property variation leads to a variation in the POF output power when a constant stress is applied to the fiber due to the stress-optical effect. The fiber mechanical properties are characterized through a dynamic mechanical analysis, and the output power variation with different temperatures is measured. The stress is applied to the fiber by means of a 180° curvature, and supports are positioned on the fiber to inhibit the variation in its curvature with the temperature variation. Results show that the sensor proposed has a sensitivity of 1.04 × 10 -3 °C -1 , a linearity of 0.994, and a root mean squared error of 1.48 °C, which indicates a relative error of below 2%, which is lower than the ones obtained for intensity-variation-based temperature sensors. Furthermore, the sensor is able to operate at temperatures up to 110 °C, which is higher than the ones obtained for similar POF sensors in the literature.

Annealing effects on strain and stress sensitivity of polymer optical fibre based sensors

DEFF Research Database (Denmark)

Pospori, A.; Marques, C. A. F.; Zubel, M. G.

2016-01-01

The annealing effects on strain and stress sensitivity of polymer optical fibre Bragg grating sensors after their photoinscription are investigated. PMMA optical fibre based Bragg grating sensors are first photo-inscribed and then they were placed into hot water for annealing. Strain, stress...... fibre tends to increase the strain, stress and force sensitivity of the photo-inscribed sensor....

Detection of Cadmium Ion by Evanescent Wave Based Chitosan Coated Optical Fiber Sensor

International Nuclear Information System (INIS)

Yulianti, I; Edy, S S; Saputra, B A; Aji, M P; Susanto; Kurdi, O

2017-01-01

Evanescent wave based-optical fiber sensor to detect cadmium ion is proposed. Chitosan was used by using the dip-coating method. The sensor was fabricated in U-bent shape. U-bent optical sensor at aconcentration of 2ppm and 5ppm had asensitivity of 0.2067 dBm/ppm and -0.7995 dBm/ppm, respectively. At a level of 2ppm - 5ppm, the optical sensor has a linear response with asensitivity of -0.283 dBm/ppm. The sensor takes 9.5 minutes to reach steady stateat aconcentration of 1 ppm. Atalevel of 2ppm - 5ppm, the sensor takes 5 minutes to 10.45 minutes to reach steady state. (paper)

Robust optical sensors for safety critical automotive applications

Science.gov (United States)

De Locht, Cliff; De Knibber, Sven; Maddalena, Sam

2008-02-01

Optical sensors for the automotive industry need to be robust, high performing and low cost. This paper focuses on the impact of automotive requirements on optical sensor design and packaging. Main strategies to lower optical sensor entry barriers in the automotive market include: Perform sensor calibration and tuning by the sensor manufacturer, sensor test modes on chip to guarantee functional integrity at operation, and package technology is key. As a conclusion, optical sensor applications are growing in automotive. Optical sensor robustness matured to the level of safety critical applications like Electrical Power Assisted Steering (EPAS) and Drive-by-Wire by optical linear arrays based systems and Automated Cruise Control (ACC), Lane Change Assist and Driver Classification/Smart Airbag Deployment by camera imagers based systems.

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.

Engineering surface plasmon based fiber-optic sensors

International Nuclear Information System (INIS)

Dhawan, Anuj; Muth, John F.

2008-01-01

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

Engineering surface plasmon based fiber-optic sensors

Energy Technology Data Exchange (ETDEWEB)

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

2008-04-15

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

Improved Optical Fiber Chemical Sensors

Science.gov (United States)

Egalon, Claudio O.; Rogowski, Robert S.

1994-01-01

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

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.

Optical-Based Artificial Palpation Sensors for Lesion Characterization

Directory of Open Access Journals (Sweden)

Hee-Jun Park

2013-08-01

Full Text Available Palpation techniques are widely used in medical procedures to detect the presence of lumps or tumors in the soft breast tissues. Since these procedures are very subjective and depend on the skills of the physician, it is imperative to perform detailed a scientific study in order to develop more efficient medical sensors to measure and generate palpation parameters. In this research, we propose an optical-based, artificial palpation sensor for lesion characterization. This has been developed using a multilayer polydimethylsiloxane optical waveguide. Light was generated at the critical angle to reflect totally within the flexible and transparent waveguide. When a waveguide was compressed by an external force, its contact area would deform and cause the light to scatter. The scattered light was captured by a high-resolution camera and saved as an image format. To test the performance of the proposed system, we used a realistic tissue phantom with embedded hard inclusions. The experimental results show that the proposed sensor can detect inclusions and provide the relative value of size, depth, and Young’s modulus of an inclusion.

Single Mode Optical Fiber based Refractive Index Sensor using Etched Cladding

OpenAIRE

Kumar, Ajay; Gupta, Geeta; Mallik, Arun; Bhatnagar, Anuj

2011-01-01

The use of optical fiber for sensor applications is a topic of current interest. We report the fabrication of etched single mode optical fiber based refractive index sensor. Experiments are performed to determine the etch rate of fiber in buffered hydrofluoric acid, which can be high or low depending upon the temperature at which etching is carried out. Controlled wet etching of fiber cladding is performed using these measurements and etched fiber region is tested for refractive index sensing...

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

Science.gov (United States)

Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

2015-01-01

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

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

Science.gov (United States)

Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

2015-09-30

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

Transformer Temperature Measurment Using Optical Fiber Based Microbend Sensor

Directory of Open Access Journals (Sweden)

Deepika YADAV

2007-10-01

Full Text Available Breakdown of transformers proves to be very expensive and inconvenient because it takes a lot of time for their replacement. During breakdown the industry also incurs heavy losses because of stoppage in production line. A system for monitoring the temperature of transformers is required. Existing sensors cannot be used for monitoring the temperature of transformers because they are sensitive to electrical signals and can cause sparking which can trigger fire since there is oil in transformers cooling coils. Optical fibers are electrically inert so this system will prove to be ideal for this application. Results of investigations carried out by simulating a configuration of Optical Fiber Temperature Sensor for transformers based on microbending using Matlab as a simulation tool to evaluate the effectiveness of this sensor have been communicated through this manuscript. The results are in the form of graphs of intensity modulation vs. the temperature.

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.

Planar location of the simulative acoustic source based on fiber optic sensor array

Science.gov (United States)

Liang, Yi-Jun; Liu, Jun-feng; Zhang, Qiao-ping; Mu, Lin-lin

2010-06-01

A fiber optic sensor array which is structured by four Sagnac fiber optic sensors is proposed to detect and locate a simulative source of acoustic emission (AE). The sensing loops of Sagnac interferometer (SI) are regarded as point sensors as their small size. Based on the derived output light intensity expression of SI, the optimum work condition of the Sagnac fiber optic sensor is discussed through the simulation of MATLAB. Four sensors are respectively placed on a steel plate to structure the sensor array and the location algorithms are expatiated. When an impact is generated by an artificial AE source at any position of the plate, the AE signal will be detected by four sensors at different times. With the help of a single chip microcomputer (SCM) which can calculate the position of the AE source and display it on LED, we have implemented an intelligent detection and location.

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

Directory of Open Access Journals (Sweden)

J. Gabriel Ortega-Mendoza

2014-10-01

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

Optical Fiber-Tip Sensors Based on In-Situ µ-Printed Polymer Suspended-Microbeams.

Science.gov (United States)

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

2018-06-05

Miniature optical fiber-tip sensors based on directly µ-printed polymer suspended-microbeams are presented. With an in-house optical 3D μ-printing technology, SU-8 suspended-microbeams are fabricated in situ to form Fabry⁻Pérot (FP) micro-interferometers on the end face of standard single-mode optical fiber. Optical reflection spectra of the fabricated FP micro-interferometers are measured and fast Fourier transform is applied to analyze the cavity of micro-interferometers. The applications of the optical fiber-tip sensors for refractive index (RI) sensing and pressure sensing, which showed 917.3 nm/RIU to RI change and 4.29 nm/MPa to pressure change, respectively, are demonstrated in the experiments. The sensors and their optical µ-printing method unveil a new strategy to integrate complicated microcomponents on optical fibers toward 'lab-on-fiber' devices and applications.

Optical sensor in planar configuration based on multimode interference

Science.gov (United States)

Blahut, Marek

2017-08-01

In the paper a numerical analysis of optical sensors based on multimode interference in planar one-dimensional step-index configuration is presented. The structure consists in single-mode input and output waveguides and multimode waveguide which guide only few modes. Material parameters discussed refer to a SU8 polymer waveguide on SiO2 substrate. The optical system described will be designed to the analysis of biological substances.

Kalman filter-based EM-optical sensor fusion for needle deflection estimation.

Science.gov (United States)

Jiang, Baichuan; Gao, Wenpeng; Kacher, Daniel; Nevo, Erez; Fetics, Barry; Lee, Thomas C; Jayender, Jagadeesan

2018-04-01

In many clinical procedures such as cryoablation that involves needle insertion, accurate placement of the needle's tip at the desired target is the major issue for optimizing the treatment and minimizing damage to the neighboring anatomy. However, due to the interaction force between the needle and tissue, considerable error in intraoperative tracking of the needle tip can be observed as needle deflects. In this paper, measurements data from an optical sensor at the needle base and a magnetic resonance (MR) gradient field-driven electromagnetic (EM) sensor placed 10 cm from the needle tip are used within a model-integrated Kalman filter-based sensor fusion scheme. Bending model-based estimations and EM-based direct estimation are used as the measurement vectors in the Kalman filter, thus establishing an online estimation approach. Static tip bending experiments show that the fusion method can reduce the mean error of the tip position estimation from 29.23 mm of the optical sensor-based approach to 3.15 mm of the fusion-based approach and from 39.96 to 6.90 mm, at the MRI isocenter and the MRI entrance, respectively. This work established a novel sensor fusion scheme that incorporates model information, which enables real-time tracking of needle deflection with MRI compatibility, in a free-hand operating setup.

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.

Highly Sensitive Temperature Sensors Based on Fiber-Optic PWM and Capacitance Variation Using Thermochromic Sensing Membrane

Directory of Open Access Journals (Sweden)

Md. Rajibur Rahaman Khan

2016-07-01

Full Text Available In this paper, we propose a temperature/thermal sensor that contains a Rhodamine-B sensing membrane. We applied two different sensing methods, namely, fiber-optic pulse width modulation (PWM and an interdigitated capacitor (IDC-based temperature sensor to measure the temperature from 5 °C to 100 °C. To the best of our knowledge, the fiber-optic PWM-based temperature sensor is reported for the first time in this study. The proposed fiber-optic PWM temperature sensor has good sensing ability; its sensitivity is ~3.733 mV/°C. The designed temperature-sensing system offers stable sensing responses over a wide dynamic range, good reproducibility properties with a relative standard deviation (RSD of ~0.021, and the capacity for a linear sensing response with a correlation coefficient of R2 ≈ 0.992 over a wide sensing range. In our study, we also developed an IDC temperature sensor that is based on the capacitance variation principle as the IDC sensing element is heated. We compared the performance of the proposed temperature-sensing systems with different fiber-optic temperature sensors (which are based on the fiber-optic wavelength shift method, the long grating fiber-optic Sagnac loop, and probe type fiber-optics in terms of sensitivity, dynamic range, and linearity. We observed that the proposed sensing systems have better sensing performance than the above-mentioned sensing system.

Sol gel based fiber optic sensor for blook pH measurement

International Nuclear Information System (INIS)

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

1996-01-01

This paper describes a fiber-optic pH sensor based upon sol-gel encapsulation of a self-referencing dye, seminaphthorhodamine-1 carboxylate (SNARF-1C). The simple sol-gel fabrication procedure and low coating leachability are ideal for encapsulation and immobilization of dye molecules onto the end of an optical fiber. A miniature bench-top fluorimeter system was developed for use with the optical fiber to obtain pH measurements. Linear and reproducible responses were obtained in human blood in the pH range 6.8 to 8.0, which encompasses the clinically-relevant range. Therefore, this sensor can be considered for in vivo use

Novel Fiber-Optic Ring Acoustic Emission Sensor.

Science.gov (United States)

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

2018-01-13

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

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.

Fiber optic sensor based on reflectivity configurations to detect heart rate

Science.gov (United States)

Yunianto, M.; Marzuki, A.; Riyatun, R.; Lestari, D.

2016-11-01

Research of optical fiber-based heart rate detection sensor has been conducted using the reflection configurationon the thorax motion modified. Optical fiber used in this research was Plastic Optical Fiber (POF) with a diameter of 0.5. Optical fiber system is made with two pieces of fiber, the first fiber is to serve as a transmitter transmitting light from the source to the reflector membrane, the second fiber serves as a receiver. One of the endsfrom the two fibersis pressed and positioned perpendicular of reflector membrane which is placed on the surface of the chest. The sensor works on the principle of intensity changes captured by the receiver fiber when the reflector membrane gets the vibe from the heart. The light source used is in the form of Light Emitting Diode (LED) and Light Dependent Resistor (LDR) as a light sensor. Variations are performed on the reflector membrane diameter. The light intensity received by the detector increases along with the increasing width of the reflector membrane diameter. The results show that this sensor can detect the harmonic peak at a frequency of 1.5 Hz; 7.5 Hz; 10.5 Hz; and 22.5 Hz in a healthy human heart with an average value of Beat Per Minute (BPM) by 78 times, a prototype sensor that is made can work and function properly.

Quasidistributed temperature sensor based on dense wavelength-division multiplexing optical fiber delay

Science.gov (United States)

Su, Jun; Yang, Ning; Fan, Zhiqiang; Qiu, Qi

2017-10-01

We report on a fiber-optic delay-based quasidistributed temperature sensor with high precision. The device works by detecting the delay induced by the temperature instead of the spectrum. To analyze the working principle of this sensor, the thermal dependence of the fiber-optic delay was theoretically investigated and the delay-temperature coefficient was measured to be 42.2 ps/km°C. In this sensor, quasidistributed measurement of temperature could be easily realized by dense wavelength-division multiplexing and wavelength addressing. We built and tested a prototype quasidistributed temperature sensor with eight testing points equally distributed along a 32.61-km-long fiber. The experimental results demonstrate an average error of economic temperature measurements.

Novel Fiber-Optic Ring Acoustic Emission Sensor

Directory of Open Access Journals (Sweden)

Peng Wei

2018-01-01

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

Optical fiber relative humidity sensor based on a FBG with a di-ureasil coating.

Science.gov (United States)

Correia, Sandra F H; Antunes, Paulo; Pecoraro, Edison; Lima, Patrícia P; Varum, Humberto; Carlos, Luis D; Ferreira, Rute A S; André, Paulo S

2012-01-01

In this work we proposed a relative humidity (RH) sensor based on a Bragg grating written in an optical fiber, associated with a coating of organo-silica hybrid material prepared by the sol-gel method. The organo-silica-based coating has a strong adhesion to the optical fiber and its expansion is reversibly affected by the change in the RH values (15.0-95.0%) of the surrounding environment, allowing an increased sensitivity (22.2 pm/%RH) and durability due to the presence of a siliceous-based inorganic component. The developed sensor was tested in a real structure health monitoring essay, in which the RH inside two concrete blocks with different porosity values was measured over 1 year. The results demonstrated the potential of the proposed optical sensor in the monitoring of civil engineering structures.

Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review.

Science.gov (United States)

Ding, Zhenyang; Wang, Chenhuan; Liu, Kun; Jiang, Junfeng; Yang, Di; Pan, Guanyi; Pu, Zelin; Liu, Tiegen

2018-04-03

Distributed optical fiber sensors (DOFS) offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR) has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on.

UV Radiation Detection Using Optical Sensor Based on Eu3+ Doped PMMA

Directory of Open Access Journals (Sweden)

Miluski Piotr

2016-12-01

Full Text Available Progress in UV treatment applications requires new compact and sensor constructions. In the paper a hybrid (organic-inorganic rare-earth-based polymeric UV sensor construction is proposed. The efficient luminescence of poly(methyl methacrylate (PMMA matrix doped by europium was used for testing the optical sensor (optrode construction. The europium complex assures effective luminescence in the visible range with well determined multi-peak spectrum emission enabling construction of the optrode. The fabricated UV optical fibre sensor was used for determination of Nd:YAG laser intensity measurements at the third harmonic (355 nm in the radiation power range 5.0-34.0 mW. The multi-peak luminescence spectrum was used for optimization of the measurement formula. The composition of luminescent peak intensity enables to increase the slope of sensitivity up to −2.8 mW-1. The obtained results and advantages of the optical fibre construction enable to apply it in numerous UV detection systems.

Highly versatile fiber-based optical Fabry-Pérot gas sensor.

Science.gov (United States)

Liu, Jing; Sun, Yuze; Fan, Xudong

2009-02-16

We develop a versatile, compact, and sensitive fiber-based optical Fabry-Pérot (FP) gas sensor. The sensor probe is composed of a silver layer and a vapor-sensitive polymer layer that are sequentially deposited on the cleaved fiber endface, thus forming an FP cavity. The interference spectrum resulting from the reflected light at the silver-polymer and polymer-air interfaces changes when the polymer is exposed to gas analytes. This structure enables using any polymer regardless of the polymer refractive index (RI), which significantly enhances the sensor versatility. In experiments, we use polyethylene glycol (PEG) 400 (RI=1.465-1.469) and Norland Optical Adhesive (NOA) 81 (RI=1.53-1.56) as the gas sensing polymer and show drastically different sensor response to hexanol, methanol, and acetone. The estimated sensitivity for methanol vapor is 3.5 pm/ppm and 0.1 pm/ppm for PEG 400 and NOA 81, respectively, with a detection limit on the order of 1-10 ppm. Gas sensing for the analytes delivered in both continuous flow mode and pulsed mode is demonstrated.

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

Czech Academy of Sciences Publication Activity Database

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

2015-01-01

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

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

Science.gov (United States)

Wang, Huaping; Jiang, Lizhong; Xiang, Ping

2018-05-01

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

Recent Developments in Fiber Optics Humidity Sensors.

Science.gov (United States)

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

2017-04-19

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

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

DEFF Research Database (Denmark)

Zhang, Liang; Lu, Ping; Chen, Li

2012-01-01

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

BER Analysis of Coherent Free-Space Optical Communication Systems with a Focal-Plane-Based Wavefront Sensor

Science.gov (United States)

Cao, Jingtai; Zhao, Xiaohui; Liu, Wei; Gu, Haijun

2018-03-01

A wavefront sensor is one of most important units for an adaptive optics system. Based on our previous works, in this paper, we discuss the bit-error-rate (BER) performance of coherent free space optical communication systems with a focal-plane-based wavefront sensor. Firstly, the theory of a focal-plane-based wavefront sensor is given. Then the relationship between the BER and the mixing efficiency with a homodyne receiver is discussed on the basis of binary-phase-shift-keying (BPSK) modulation. Finally, the numerical simulation results are shown that the BER will be decreased obviously after aberrations correction with the focal-plane-based wavefront sensor. In addition, the BER will decrease along with increasing number of photons received within a single bit. These analysis results will provide a reference for the design of the coherent Free space optical communication (FSOC) system.

Intrusion recognition for optic fiber vibration sensor based on the selective attention mechanism

Science.gov (United States)

Xu, Haiyan; Xie, Yingjuan; Li, Min; Zhang, Zhuo; Zhang, Xuewu

2017-11-01

Distributed fiber-optic vibration sensors receive extensive investigation and play a significant role in the sensor panorama. A fiber optic perimeter detection system based on all-fiber interferometric sensor is proposed, through the back-end analysis, processing and intelligent identification, which can distinguish effects of different intrusion activities. In this paper, an intrusion recognition based on the auditory selective attention mechanism is proposed. Firstly, considering the time-frequency of vibration, the spectrogram is calculated. Secondly, imitating the selective attention mechanism, the color, direction and brightness map of the spectrogram is computed. Based on these maps, the feature matrix is formed after normalization. The system could recognize the intrusion activities occurred along the perimeter sensors. Experiment results show that the proposed method for the perimeter is able to differentiate intrusion signals from ambient noises. What's more, the recognition rate of the system is improved while deduced the false alarm rate, the approach is proved by large practical experiment and project.

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.

Optical Fibre Pressure Sensors in Medical Applications.

Science.gov (United States)

Poeggel, Sven; Tosi, Daniele; Duraibabu, DineshBabu; Leen, Gabriel; McGrath, Deirdre; Lewis, Elfed

2015-07-15

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.

Optical Fibre Pressure Sensors in Medical Applications

Science.gov (United States)

Poeggel, Sven; Tosi, Daniele; Duraibabu, DineshBabu; Leen, Gabriel; McGrath, Deirdre; Lewis, Elfed

2015-01-01

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. PMID:26184228

Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review

Directory of Open Access Journals (Sweden)

Zhenyang Ding

2018-04-01

Full Text Available Distributed optical fiber sensors (DOFS offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on.

Distributed Optical Fiber Sensors Based on Optical Frequency Domain Reflectometry: A review

Science.gov (United States)

Wang, Chenhuan; Liu, Kun; Jiang, Junfeng; Yang, Di; Pan, Guanyi; Pu, Zelin; Liu, Tiegen

2018-01-01

Distributed optical fiber sensors (DOFS) offer unprecedented features, the most unique one of which is the ability of monitoring variations of the physical and chemical parameters with spatial continuity along the fiber. Among all these distributed sensing techniques, optical frequency domain reflectometry (OFDR) has been given tremendous attention because of its high spatial resolution and large dynamic range. In addition, DOFS based on OFDR have been used to sense many parameters. In this review, we will survey the key technologies for improving sensing range, spatial resolution and sensing performance in DOFS based on OFDR. We also introduce the sensing mechanisms and the applications of DOFS based on OFDR including strain, stress, vibration, temperature, 3D shape, flow, refractive index, magnetic field, radiation, gas and so on. PMID:29614024

Towards a Uniform Metrological Assessment of Grating-Based Optical Fiber Sensors: From Refractometers to Biosensors.

Science.gov (United States)

Chiavaioli, Francesco; Gouveia, Carlos A J; Jorge, Pedro A S; Baldini, Francesco

2017-06-21

A metrological assessment of grating-based optical fiber sensors is proposed with the aim of providing an objective evaluation of the performance of this sensor category. Attention was focused on the most common parameters, used to describe the performance of both optical refractometers and biosensors, which encompassed sensitivity, with a distinction between volume or bulk sensitivity and surface sensitivity, resolution, response time, limit of detection, specificity (or selectivity), reusability (or regenerability) and some other parameters of generic interest, such as measurement uncertainty, accuracy, precision, stability, drift, repeatability and reproducibility. Clearly, the concepts discussed here can also be applied to any resonance-based sensor, thus providing the basis for an easier and direct performance comparison of a great number of sensors published in the literature up to now. In addition, common mistakes present in the literature made for the evaluation of sensor performance are highlighted, and lastly a uniform performance assessment is discussed and provided. Finally, some design strategies will be proposed to develop a grating-based optical fiber sensing scheme with improved performance.

Metal-Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform.

Science.gov (United States)

Kim, Ki-Joong; Lu, Ping; Culp, Jeffrey T; Ohodnicki, Paul R

2018-02-23

Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal-organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability of MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO 2 gas relative to other small gases (H 2 , N 2 , O 2 , and CO) with rapid (optical fiber platform which results in an amplification of inherent optical absorption present within the MOF-based sensing layer with increasing values of effective refractive index associated with adsorption of gases.

Design of a base station for MEMS CCR localization in an optical sensor network.

Science.gov (United States)

Park, Chan Gook; Jeon, Hyun Cheol; Kim, Hyoun Jin; Kim, Jae Yoon

2014-05-08

This paper introduces a design and implementation of a base station, capable of positioning sensor nodes using an optical scheme. The base station consists of a pulse laser module, optical detectors and beam splitter, which are mounted on a rotation-stage, and a Time to Digital Converter (TDC). The optical pulse signal transmitted to the sensor node with a Corner Cube Retro-reflector (CCR) is reflected to the base station, and the Time of Flight (ToF) data can be obtained from the two detectors. With the angle and flight time data, the position of the sensor node can be calculated. The performance of the system is evaluated by using a commercial CCR. The sensor nodes are placed at different angles from the base station and scanned using the laser. We analyze the node position error caused by the rotation and propose error compensation methods, namely the outlier sample exception and decreasing the confidence factor steadily using the recursive least square (RLS) methods. Based on the commercial CCR results, the MEMS CCR is also tested to demonstrate the compatibility between the base station and the proposed methods. The result shows that the localization performance of the system can be enhanced with the proposed compensation method using the MEMS CCR.

Design of a Base Station for MEMS CCR Localization in an Optical Sensor Network

Directory of Open Access Journals (Sweden)

Chan Gook Park

2014-05-01

Full Text Available This paper introduces a design and implementation of a base station, capable of positioning sensor nodes using an optical scheme. The base station consists of a pulse laser module, optical detectors and beam splitter, which are mounted on a rotation-stage, and a Time to Digital Converter (TDC. The optical pulse signal transmitted to the sensor node with a Corner Cube Retro-reflector (CCR is reflected to the base station, and the Time of Flight (ToF data can be obtained from the two detectors. With the angle and flight time data, the position of the sensor node can be calculated. The performance of the system is evaluated by using a commercial CCR. The sensor nodes are placed at different angles from the base station and scanned using the laser. We analyze the node position error caused by the rotation and propose error compensation methods, namely the outlier sample exception and decreasing the confidence factor steadily using the recursive least square (RLS methods. Based on the commercial CCR results, the MEMS CCR is also tested to demonstrate the compatibility between the base station and the proposed methods. The result shows that the localization performance of the system can be enhanced with the proposed compensation method using the MEMS CCR.

Polymer Optical Fiber Compound Parabolic Concentrator fiber tip based glucose sensor: In-Vitro Testing

DEFF Research Database (Denmark)

Hassan, Hafeez Ul; Janting, Jakob; Aasmul, Soren

2016-01-01

We present in-vitro sensing of glucose using a newly developed efficient optical fiber glucose sensor based on a Compound Parabolic Concentrator (CPC) tipped polymer optical fiber (POF). A batch of 9 CPC tipped POF sensors with a 35 mm fiber length is shown to have an enhanced fluorescence pickup...... efficiency with an average increment factor of 1.7 as compared to standard POF sensors with a plane cut fiber tip. Invitro measurements for two glucose concentrations (40 and 400 mg/dL) confirm that the CPC tipped sensors efficiently can detect both glucose concentrations. it sets the footnote at the bottom...

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.

Embedded fiber optic ultrasonic sensors and generators

Science.gov (United States)

Dorighi, John F.; Krishnaswamy, Sridhar; Achenbach, Jan D.

1995-04-01

Ultrasonic sensors and generators based on fiber-optic systems are described. It is shown that intrinsic fiber optic Fabry-Perot ultrasound sensors that are embedded in a structure can be stabilized by actively tuning the laser frequency. The need for this method of stabilization is demonstrated by detecting piezoelectric transducer-generated ultrasonic pulses in the presence of low frequency dynamic strains that are intentionally induced to cause sensor drift. The actively stabilized embedded fiber optic Fabry-Perot sensor is also shown to have sufficient sensitivity to detect ultrasound that is generated in the interior of a structure by means of a high-power optical fiber that pipes energy from a pulsed laser to an embedded generator of ultrasound.

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...

Introduction to optical fiber sensors

International Nuclear Information System (INIS)

Moukdad, S.

1991-01-01

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

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

DEFF Research Database (Denmark)

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

2012-01-01

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

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

Energy Technology Data Exchange (ETDEWEB)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi [Soonchunhyang Univ., Asan (Korea, Republic of)

2016-10-15

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research.

A Study on the Response Characteristics of a Fiber-Optic Radiation Sensor Model Based on Cerenkov Principle

International Nuclear Information System (INIS)

Han, Hwa Jeong; Kim, Beom Kyu; Park, Byung Gi

2016-01-01

In recent year, various fiber-optic radiation sensors using Cerenkov principle have been developed without employing any scintillators for measuring high-energy photon, electron, etc. The main advantages of the optical fibers are the remote transmission of the light signal and immunity to pressure and electromagnetic waves. Therefore, the sensors utilizing the optical fibers can be used in hazardous radiation environments, such as the high-level radiation areas of a nuclear facility. The study to be simulated a fiber-optic radiation sensor based on Cerenkov principle and to be analyzed the response characteristics of the sensor. For the aforementioned study, the GEANT simulation toolkit was used. It is able to take into all the optical properties of fibers and is found to be appropriate to realistically describe the response of fiber-optic radiation sensor. In the recently, the fiber-optic radiation sensor have been developed in nuclear industry. Because sensor can detect gamma ray in harsh nuclear environments. In this study, we analyzed response characteristics of the fiber-optic radiation sensor. We have simulated the Monte Carlo model, for detecting the Cerenkov radiation using the fiber-optic radiation sensor. And the y-axis distribution of Cerenkov photons was obtained using output file. Simulation is performed with reference to the method of the previous research, and then the simulation results exhibited a good agreement with the previous research

Composite cavity based fiber optic Fabry–Perot strain sensors demodulated by an unbalanced fiber optic Michelson interferometer with an electrical scanning mirror

International Nuclear Information System (INIS)

Zhang, Jianzhong; Yang, Jun; Sun, Weimin; Yuan, Libo; Jin, Wencai; Peng, G D

2008-01-01

A composite cavity based fiber optic Fabry–Perot strain sensor system, interrogated by a white light source and demodulated by an unbalanced fiber optic Michelson interferometer with an electrical scanning mirror, is proposed and demonstrated. Comparing with the traditional extrinsic fiber optic Fabry–Perot strain sensor, the potential multiplexing capability and the dynamic measurement range are improved simultaneously. At the same time, the measurement stability of the electrical scanning mirror system is improved by the self-referenced signal of the sensor structure

Fiber optic sensor based on Mach-Zehnder interferometer for securing entrance areas of buildings

Science.gov (United States)

Nedoma, Jan; Fajkus, Marcel; Martinek, Radek; Mec, Pavel; Novak, Martin; Bednarek, Lukas; Vasinek, Vladimir

2017-10-01

Authors of this article focused on the utilization of fiber optic sensors based on interferometric measurements for securing entrance areas of buildings such as windows and doors. We described the implementation of the fiber-optic interferometer (type Mach-Zehnder) into the window frame or door, sensor sensitivity, analysis of the background noise and methods of signal evaluation. The advantage of presented solution is the use of standard telecommunication fiber standard G.652.D, high sensitivity, immunity of sensor to electromagnetic interference (EMI) and passivity of the sensor regarding power supply. Authors implemented the Graphical User Interface (GUI) which offers the possibility of remote monitoring presented sensing solution.

Fiber optic pressure sensors for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

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

1995-04-01

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

Fiber optic pressure sensors for nuclear power plants

International Nuclear Information System (INIS)

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

1995-01-01

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

Micro-controller based air pressure monitoring instrumentation system using optical fibers as sensor

Science.gov (United States)

Hazarika, D.; Pegu, D. S.

2013-03-01

This paper describes a micro-controller based instrumentation system to monitor air pressure using optical fiber sensors. The principle of macrobending is used to develop the sensor system. The instrumentation system consists of a laser source, a beam splitter, two multi mode optical fibers, two Light Dependent Resistance (LDR) based timer circuits and a AT89S8252 micro-controller. The beam splitter is used to divide the laser beam into two parts and then these two beams are launched into two multi mode fibers. One of the multi mode fibers is used as the sensor fiber and the other one is used as the reference fiber. The use of the reference fiber is to eliminate the environmental effects while measuring the air pressure magnitude. The laser beams from the sensor and reference fibers are applied to two identical LDR based timer circuits. The LDR based timer circuits are interfaced to a micro-controller through its counter pins. The micro-controller samples the frequencies of the timer circuits using its counter-0 and counter-1 and the counter values are then processed to provide the measure of air pressure magnitude.

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

Optical fiber sensors: Systems and applications. Volume 2

Science.gov (United States)

Culshaw, Brian; Dakin, John

State-of-the-art fiber-optic (FO) sensors and their applications are described in chapters contributed by leading experts. Consideration is given to interferometers, FO gyros, intensity- and wavelength-based sensors and optical actuators, Si in FO sensors, point-sensor multiplexing principles, and distributed FO sensor systems. Also examined are chemical, biochemical, and medical sensors; physical and chemical sensors for process control; FO-sensor applications in the marine and aerospace industries; FO-sensor monitoring systems for security and safety, structural integrity, NDE, and the electric-power industry; and the market situation for FO-sensor technology. Diagrams, drawings, graphs, and photographs are provided.

A novel pH optical sensor using methyl orange based on triacetylcellulose membranes as support.

Science.gov (United States)

Hosseini, Mohammad; Heydari, Rouhollah; Alimoradi, Mohammad

2014-07-15

A novel pH optical sensor based on triacetylcellulose membrane as solid support was developed by using immobilization of methyl orange indicator. The prepared optical sensor was fixed into a flow cell for on-line pH monitoring. Variables affecting sensor performance, such as pH of dye bonding to triacetylcellulose membrane and dye concentration have been fully evaluated and optimized. The calibration curve showed good behavior and precision (RSDpH range of 4.0-12.0. No significant variation was observed on sensor response with increasing the ionic strength in the range of 0.0-0.5M of sodium chloride. Determination of pH by using the proposed optical sensor is on-line, quick, inexpensive, selective and sensitive in the pH range of 4.0-12.0. Copyright © 2014 Elsevier B.V. All rights reserved.

Optical fiber sensors embedded in flexible polymer foils

Science.gov (United States)

van Hoe, Bram; van Steenberge, Geert; Bosman, Erwin; Missinne, Jeroen; Geernaert, Thomas; Berghmans, Francis; Webb, David; van Daele, Peter

2010-04-01

In traditional electrical sensing applications, multiplexing and interconnecting the different sensing elements is a major challenge. Recently, many optical alternatives have been investigated including optical fiber sensors of which the sensing elements consist of fiber Bragg gratings. Different sensing points can be integrated in one optical fiber solving the interconnection problem and avoiding any electromagnetical interference (EMI). Many new sensing applications also require flexible or stretchable sensing foils which can be attached to or wrapped around irregularly shaped objects such as robot fingers and car bumpers or which can even be applied in biomedical applications where a sensor is fixed on a human body. The use of these optical sensors however always implies the use of a light-source, detectors and electronic circuitry to be coupled and integrated with these sensors. The coupling of these fibers with these light sources and detectors is a critical packaging problem and as it is well-known the costs for packaging, especially with optoelectronic components and fiber alignment issues are huge. The end goal of this embedded sensor is to create a flexible optical sensor integrated with (opto)electronic modules and control circuitry. To obtain this flexibility, one can embed the optical sensors and the driving optoelectronics in a stretchable polymer host material. In this article different embedding techniques for optical fiber sensors are described and characterized. Initial tests based on standard manufacturing processes such as molding and laser structuring are reported as well as a more advanced embedding technique based on soft lithography processing.

A Preliminary Test for Skin Gas Assessment Using a Porphyrin Based Evanescent Wave Optical Fiber Sensor

Directory of Open Access Journals (Sweden)

Roman SELYANCHYN

2011-02-01

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

Novel spectral fiber optic sensor based on surface plasmon resonance

Czech Academy of Sciences Publication Activity Database

Slavík, Radan; Homola, Jiří; Čtyroký, Jiří; Brynda, Eduard

B74, 1/3 (2001), s. 106-111 ISSN 0925-4005. [European Conference on Optical Chemical Sensors and Biosensors EUROPT(R)ODE /5./. Lyon-Villeurbanne, 16.04.2000-19.04.2000] R&D Projects: GA ČR GA102/99/M057; GA ČR GA102/99/0549; GA ČR GA102/00/1536 Institutional research plan: CEZ:AV0Z2067918 Keywords : fibre optic sensors * surface plasmons Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 1.440, year: 2001

A Temperature Sensor Based on a Polymer Optical Fiber Macro-Bend

Directory of Open Access Journals (Sweden)

Joseba Zubia Zaballa

2013-09-01

Full Text Available The design and development of a plastic optical fiber (POF macrobend temperature sensor is presented. The sensor has a linear response versus temperature at a fixed bend radius, with a sensitivity of . The sensor system used a dummy fiber-optic sensor for reference purposes having a resolution below 0.3 °C. A comprehensive experimental analysis was carried out to provide insight into the effect of different surrounding media on practical macro-bend POF sensor implementation. Experimental results are successfully compared with bend loss calculations.

Design of fiber optic based respiratory sensor for newborn incubator application

Science.gov (United States)

Dhia, Arika; Devara, Kresna; Abuzairi, Tomy; Poespawati, N. R.; Purnamaningsih, Retno W.

2018-02-01

This paper reports the design of respiratory sensor using fiber optic for newborn incubator application. The sensor works based on light intensity losses difference obtained due to thorax movement during respiration. The output of the sensor launched to support electronic circuits to be processed in Arduino Uno microcontroler such that the real-time respiratory rate (breath per minute) can be presented on LCD. Experiment results using thorax expansion of newborn simulator show that the system is able to measure respiratory rate from 10 up to 130 breaths per minute with 0.595% error and 0.2% hysteresis error.

[An optical-fiber-sensor-based spectrophotometer for soil non-metallic nutrient determination].

Science.gov (United States)

He, Dong-xian; Hu, Juan-xiu; Lu, Shao-kun; He, Hou-yong

2012-01-01

In order to achieve rapid, convenient and efficient soil nutrient determination in soil testing and fertilizer recommendation, a portable optical-fiber-sensor-based spectrophotometer including immersed fiber sensor, flat field holographic concave grating, and diode array detector was developed for soil non-metallic nutrient determination. According to national standard of ultraviolet and visible spectrophotometer with JJG 178-2007, the wavelength accuracy and repeatability, baseline stability, transmittance accuracy and repeatability measured by the prototype instrument were satisfied with the national standard of III level; minimum spectral bandwidth, noise and excursion, and stray light were satisfied with the national standard of IV level. Significant linear relationships with slope of closing to 1 were found between the soil available nutrient contents including soil nitrate nitrogen, ammonia nitrogen, available phosphorus, available sulfur, available boron, and organic matter measured by the prototype instrument compared with that measured by two commercial single-beam-based and dual-beam-based spectrophotometers. No significant differences were revealed from the above comparison data. Therefore, the optical-fiber-sensor-based spectrophotometer can be used for rapid soil non-metallic nutrient determination with a high accuracy.

Biochemical component identification by plasmonic improved whispering gallery mode optical resonance based sensor

Science.gov (United States)

Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

2014-05-01

Experimental data on detection and identification of variety of biochemical agents, such as proteins, microelements, antibiotic of different generation etc. in both single and multi component solutions under varied in wide range concentration analyzed on the light scattering parameters of whispering gallery mode optical resonance based sensor are represented. Multiplexing on parameters and components has been realized using developed fluidic sensor cell with fixed in adhesive layer dielectric microspheres and data processing. Biochemical component identification has been performed by developed network analysis techniques. Developed approach is demonstrated to be applicable both for single agent and for multi component biochemical analysis. Novel technique based on optical resonance on microring structures, plasmon resonance and identification tools has been developed. To improve a sensitivity of microring structures microspheres fixed by adhesive had been treated previously by gold nanoparticle solution. Another technique used thin film gold layers deposited on the substrate below adhesive. Both biomolecule and nanoparticle injections caused considerable changes of optical resonance spectra. Plasmonic gold layers under optimized thickness also improve parameters of optical resonance spectra. Biochemical component identification has been also performed by developed network analysis techniques both for single and for multi component solution. So advantages of plasmon enhancing optical microcavity resonance with multiparameter identification tools is used for development of a new platform for ultra sensitive label-free biomedical sensor.

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique.

Science.gov (United States)

Khan, Md Rajibur Rahaman; Kang, Shin-Won

2016-11-09

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal's pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R² is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry-Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors.

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

Science.gov (United States)

Khan, Md. Rajibur Rahaman; Kang, Shin-Won

2016-01-01

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal’s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R2 is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry–Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors. PMID:27834865

Photocured thiol-ene based optical fluorescence sensor for determination of gold(III)

Energy Technology Data Exchange (ETDEWEB)

Çubuk, Soner, E-mail: sonercubuk@marmara.edu.tr; Kahraman, Memet Vezir; Yetimoğlu, Ece Kök; Kenan, Sibel

2014-02-17

Graphical abstract: -- Highlights: •Photopolymerized fluorescence sensor for Au(III) analysis has been developed. •Preparation of polymeric sensor is simple and quick. •Fluorescence sensor used for analysis of Au(III) in real samples. -- Abstract: This study describes the preparation and the characterization of a new thiol-ene based polymeric fluorescence sensor by photo initiated polymerization of trimethylolpropane tris(3-mercaptopropionate), 2-hydroxyethylacrylate, and 2,4,6-triallyloxy-1,3,5-triazine which are used as monomers and also a photo initiator (2,2-dimethoxy-2-phenylacetophenone) for its usage as optical sensor for gold ions. The thiol-ene based polymeric membrane sensor was characterized by using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). The response characteristics of the sensors including dynamic range, pH effect, response time, and the effect of foreign ions were investigated. Fluorescence spectra showed that the excitation/emission maxima of the membrane were at 379/425 nm, respectively.

Photocured thiol-ene based optical fluorescence sensor for determination of gold(III)

International Nuclear Information System (INIS)

Çubuk, Soner; Kahraman, Memet Vezir; Yetimoğlu, Ece Kök; Kenan, Sibel

2014-01-01

Graphical abstract: -- Highlights: •Photopolymerized fluorescence sensor for Au(III) analysis has been developed. •Preparation of polymeric sensor is simple and quick. •Fluorescence sensor used for analysis of Au(III) in real samples. -- Abstract: This study describes the preparation and the characterization of a new thiol-ene based polymeric fluorescence sensor by photo initiated polymerization of trimethylolpropane tris(3-mercaptopropionate), 2-hydroxyethylacrylate, and 2,4,6-triallyloxy-1,3,5-triazine which are used as monomers and also a photo initiator (2,2-dimethoxy-2-phenylacetophenone) for its usage as optical sensor for gold ions. The thiol-ene based polymeric membrane sensor was characterized by using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). The response characteristics of the sensors including dynamic range, pH effect, response time, and the effect of foreign ions were investigated. Fluorescence spectra showed that the excitation/emission maxima of the membrane were at 379/425 nm, respectively

Optical acetylcholine sensor based on free base porphyrin as a chromoionophore.

Science.gov (United States)

Mroczkiewicz, Monika; Pietrzak, Mariusz; Górski, Łukasz; Malinowska, Elżbieta

2011-09-21

In this work, the possibility of application of free base porphyrin as a lipophilic pH chromoionophore for the preparation of optical cation-selective sensors was investigated. The properties of polymeric membranes, containing porphyrins of different structures, namely tetraphenylporphyrin (TPP) and octaethylporphyrin (OEP), were compared. Changes in equilibrium between protonated and deprotonated form of porphyrin, resulting from variations in ACh concentration, were evaluated. The influence of various factors (kind and quantity of anionic additive and porphyrin in the membrane phase, pH of sample solution) on initial equilibrium was studied. The best membrane composition was chosen as: TPP 3 wt.%, KTFPB 175 mol.% relative to ionophore, PVC:o-NPOE (1 : 4) and measuring buffer solution: 0.05 M MES, pH 4.5. Selectivity, response stability, reversibility and repeatability tests were carried out for chosen sensor. Developed sensor allowed for the determination of a model analyte, acetylcholine, at the concentration range of 10(-5) to 10(-2) M, both in stationary and flow-injection system. Sensor response was reversible and repeatable in the mentioned concentration range.

Optical and Microcantilever-Based Sensors for Real-Time In Situ Characterization of High-Level Waste

International Nuclear Information System (INIS)

Braun, Gilbert M.; Bryan, Samuel

2002-01-01

Fundamental research is being conducted to develop sensors for strontium that can be used in real-time to characterize high-level waste (HLW) process streams. Two fundamentally different approaches are being pursued, which have in common the dependence on highly selective molecular recognition agents. In one approach, an array of chemically selective sensors with sensitive fluorescent probes to signal the presence of the constituent of interest are coupled to fiber optics for remote analytical applications. The second approach employs sensitive microcantilever sensors that have been demonstrated to have unprecedented sensitivity in solution for Cs+ and CrO4 -. Selectivity in microcantilever-based sensors is achieved by modifying the surface of a gold-coated cantilever with a monolayer coating of an alkanethiol derivative of the molecular recognition agent. The approaches are complementary since fiber optic sensors can be deployed in the highly alkaline environment of HLW, bu t a method of immobilizing a fluorescent molecular recognition agents in a polymer film or bead on the surface of the optical fiber has yet to be demonstrated. The microcantilever-based sensors function by converting molecular complexation into surface stress, and they have been demonstrated to have the requisite sensitivity. However, we will investigate method of protecting Si or SiN microcantilever sensors in the highly alkaline environment of HLW while maintaining high selectivity. One objective of this project is to develop Sr(II) molecular recognition agents with rapidly established equilibria needed for real-time analysis, and initial research will focus on calixarene-crown ethers as a platform. Sensors for alkali metal ions, hydroxide, and temperature will be part of the array of sensor elements that will be demonstrated in this program for both the cantilever and fiber optic sensor approaches

UV-sensitive optical sensors based on ITO-gallium phosphide heterojunctions

Energy Technology Data Exchange (ETDEWEB)

Malik, Oleksandr; Hidalga-Wade, F. Javier de la; Zuniga-Islas, Carlos; Abundis Patino, Jesus H. [National Institute for Astrophysics, Optics, and Electronics (INAOE), Puebla (Mexico)

2010-04-15

Design and characteristics of wide-band UV sensors based on ITO/GaP heterostructures are discussed. Such sensors have perfect electrical parameters and high UV-visible sensitivity in comparison with surface-barrier structures using a semi-transparent thin metal film as an electrode. Many applications require UV sensors with an effective rejection of visible radiation and a wide temperature operating interval. For this aim, the theoretical modelling of extreme selective optical sensors with a double Ag/ITO thin film on the GaP surface, in which the thin silver film serves as a narrow bandpass filter at 320 nm, has been conducted. With this modelling the optimal thickness combination for the silver and ITO films was found for the maximum rejection of the sensitivity to visible radiation (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Refractive index sensor based on optical fiber end face using pulse reference-based compensation technique

Science.gov (United States)

Bian, Qiang; Song, Zhangqi; Zhang, Xueliang; Yu, Yang; Chen, Yuzhong

2018-03-01

We proposed a refractive index sensor based on optical fiber end face using pulse reference-based compensation technique. With good compensation effect of this compensation technique, the power fluctuation of light source, the change of optic components transmission loss and coupler splitting ratio can be compensated, which largely reduces the background noise. The refractive index resolutions can achieve 3.8 × 10-6 RIU and1.6 × 10-6 RIU in different refractive index regions.

A family of fiber-optic based pressure sensors for intracochlear measurements

Science.gov (United States)

Olson, Elizabeth S.; Nakajima, Hideko H.

2015-02-01

Fiber-optic pressure sensors have been developed for measurements of intracochlear pressure. The present family of transducers includes an 81 μm diameter sensor employing a SLED light source and single-mode optic fiber, and LED/multi-mode sensors with 126 and 202 μm diameter. The 126 μm diameter pressure sensor also has been constructed with an electrode adhered to its side, for coincident pressure and voltage measurements. These sensors have been used for quantifying cochlear mechanical impedances, informing our understanding of conductive hearing loss and its remediation, and probing the operation of the cochlear amplifier.

A Temperature Sensor Based on a Polymer Optical Fiber Macro-Bend

Science.gov (United States)

Moraleda, Alberto Tapetado; García, Carmen Vázquez; Zaballa, Joseba Zubia; Arrue, Jon

2013-01-01

The design and development of a plastic optical fiber (POF) macrobend temperature sensor is presented. The sensor has a linear response versus temperature at a fixed bend radius, with a sensitivity of 1.92·10−3 (°C)−1. The sensor system used a dummy fiber-optic sensor for reference purposes having a resolution below 0.3 °C. A comprehensive experimental analysis was carried out to provide insight into the effect of different surrounding media on practical macro-bend POF sensor implementation. Experimental results are successfully compared with bend loss calculations. PMID:24077323

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.

Mathematical Model of the One-stage Magneto-optical Sensor Based on Faraday Effect

Science.gov (United States)

Babaev, O. G.; Paranin, V. D.; Sinitsin, L. I.

2018-01-01

The aim of this work is to refine a model of magneto-optical sensors based on Faraday’s longitudinal magneto-optical effect. The tasks of the study include computer modeling and analysis of the transfer characteristic of a single-stage magneto-optical sensor for various polarization of the input beam and non-ideal optical components. The proposed mathematical model and software make it possible to take into account the non-ideal characteristics of film polaroids observed in operation in the near infrared region and at increased temperatures. On the basis of the results of the model analysis it was found that the dependence of normalized transmission T(γ2) has periodic nature. Choosing the angle (γ 2-γ 1) makes it possible to shift the initial operation point and change the sensitivity dT/dγ 2. The influence of the input beam polarization increases with the increase of polaroid parameter deviation from ideal and shows itself as reduction of modulation depth and angular shift of the sensor conversion response.

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...

A fibre optic oxygen sensor for monitoring of human breathing

Science.gov (United States)

Chen, Rongsheng; Farmery, Andrew D.; Chen, Rui; Hahn, Clive E. W.

2011-11-01

A reliable and cost effective fibre optic oxygen sensor for monitoring of human breathing has been developed using a normal 200μm silica core/silica cladding optical fibre and a polymer sensing matrix. The fibre optic oxygen sensor is based on the fluorescence quenching of a fluorophore by oxygen. The sensing matrix, containing immobilized Pt(II) complexes, was coated at the end of the silica core/silica cladding optical fibre. The sensitivity and time response of the sensor were evaluated using the method of luminescence lifetime measurement. The polymer substrate influence on the time response of the sensor was improved by using a fibre taper design, and the response time of the optimized sensor was less than 200ms. This silica fibre based optic oxygen sensor is suitable for monitoring of patient breathing in intensive care unit in terms of safety and low cost.

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.

Design and development of an optical fiber sensor for hydrogen detection

International Nuclear Information System (INIS)

Perrotton, Cedric

2012-01-01

Hydrogen detection is an environmental priority. Numerous hydrogen sensors have been developed, but none of them meet the industry requirements. Optical fiber sensors, electrically isolated, are excellent candidates for operating in explosive environments. Our goal is to develop an intrinsic optical fiber sensor based on Surface Plasmon Resonance. In this thesis, we study two optical fiber hydrogen sensors. The first sensor, based on amplitude modulation, consists of a thin Pd layer deposited on the multimode fiber core, after removing the optical cladding. The second design, based on wavelength modulation, consists of replacing the single Pd layer by a Au/SiO 2 /Pd multilayer stack. We demonstrate in this thesis that plasmonic sensors may be a solution to develop fast and reliable fiber hydrogen sensors. Finally, we study Mg alloys as hydrogen sensitive material in order to improve the detection range of hydrogen sensors. (author)

Improved laser-based triangulation sensor with enhanced range and resolution through adaptive optics-based active beam control.

Science.gov (United States)

Reza, Syed Azer; Khwaja, Tariq Shamim; Mazhar, Mohsin Ali; Niazi, Haris Khan; Nawab, Rahma

2017-07-20

Various existing target ranging techniques are limited in terms of the dynamic range of operation and measurement resolution. These limitations arise as a result of a particular measurement methodology, the finite processing capability of the hardware components deployed within the sensor module, and the medium through which the target is viewed. Generally, improving the sensor range adversely affects its resolution and vice versa. Often, a distance sensor is designed for an optimal range/resolution setting depending on its intended application. Optical triangulation is broadly classified as a spatial-signal-processing-based ranging technique and measures target distance from the location of the reflected spot on a position sensitive detector (PSD). In most triangulation sensors that use lasers as a light source, beam divergence-which severely affects sensor measurement range-is often ignored in calculations. In this paper, we first discuss in detail the limitations to ranging imposed by beam divergence, which, in effect, sets the sensor dynamic range. Next, we show how the resolution of laser-based triangulation sensors is limited by the interpixel pitch of a finite-sized PSD. In this paper, through the use of tunable focus lenses (TFLs), we propose a novel design of a triangulation-based optical rangefinder that improves both the sensor resolution and its dynamic range through adaptive electronic control of beam propagation parameters. We present the theory and operation of the proposed sensor and clearly demonstrate a range and resolution improvement with the use of TFLs. Experimental results in support of our claims are shown to be in strong agreement with theory.

Optical cascaded Fabry-Perot interferometer hydrogen sensor based on vernier effect

Science.gov (United States)

Li, Yina; Zhao, Chunliu; Xu, Ben; Wang, Dongning; Yang, Minghong

2018-05-01

An optical cascaded Fabry-Perot interferometer hydrogen sensor based on vernier effect has been proposed and achieved. The proposed sensor, which total length is ∼594 μm, is composed of a segment of large mode area fiber (LMAF) and a segment of hollow-core fiber (HCF). The proposed sensor is coated with the Pt-loaded WO3/SiO2 powder which will result in the increase of local temperature of the sensor head when exposed to hydrogen atmosphere. Thus the hydrogen sensor can be achieved by monitoring the change of resonant envelope wavelength. The hydrogen sensitivity is -1.04 nm/% within the range of 0 % -2.4 % which is greatly improved because of the vernier effect. The response time is ∼80 s. Due to its compact configuration, the proposed sensor provides a feasible and miniature structure to achieve detection of hydrogen.

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.

All-optical graphene oxide humidity sensors.

Science.gov (United States)

Lim, Weng Hong; Yap, Yuen Kiat; Chong, Wu Yi; Ahmad, Harith

2014-12-17

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.

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

Gold nanoparticle-based optical microfluidic sensors for analysis of environmental pollutants

DEFF Research Database (Denmark)

Lafleur, Josiane P.; Senkbeil, Silja; Jensen, Thomas G.

2012-01-01

Conventional methods of environmental analysis can be significantly improved by the development of portable microscale technologies for direct in-field sensing at remote locations. This report demonstrates the vast potential of gold nanoparticle-based microfluidic sensors for the rapid, in......-field, detection of two important classes of environmental contaminants – heavy metals and pesticides. Using gold nanoparticle-based microfluidic sensors linked to a simple digital camera as the detector, detection limits as low as 0.6 μg L−1 and 16 μg L−1 could be obtained for the heavy metal mercury...... and the dithiocarbamate pesticide ziram, respectively. These results demonstrate that the attractive optical properties of gold nanoparticle probes combine synergistically with the inherent qualities of microfluidic platforms to offer simple, portable and sensitive sensors for environmental contaminants....

Toward a multipoint optical fibre sensor system for use in process water systems based on artificial neural network pattern recognition

International Nuclear Information System (INIS)

King, D; Lyons, W B; Flanagan, C; Lewis, E

2005-01-01

An optical fibre sensor capable of detecting various concentrations of ethanol in water supplies is reported. The sensor is based on a U-bend sensor configuration and is incorporated into a 170-metre length of silica cladding silica core optical fibre. The sensor is interrogated using Optical Time Domain Reflectometry (OTDR) and it is proposed to apply artificial neural network (ANN) pattern recognition techniques to the resulting OTDR signals to accurately classify the sensor test conditions. It is also proposed that additional U-bend configuration sensors will be added to the fibre measurement length, in order to implement a multipoint optical fibre sensor system

Assessment of fiber optic pressure sensors

International Nuclear Information System (INIS)

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

1995-04-01

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

Optical Sensors for Detection of Amino Acids.

Science.gov (United States)

Pettiwala, Aafrin M; Singh, Prabhat K

2017-11-06

Amino acids are crucially involved in a myriad of biological processes. Any aberrant changes in physiological level of amino acids often manifest in common metabolic disorders, serious neurological conditions and cardiovascular diseases. Thus, devising methods for detection of trace amounts of amino acids becomes highly elemental to their efficient clinical diagnosis. Recently, the domain of developing optical sensors for detection of amino acids has witnessed significant activity which is the focus of the current review article. We undertook a detailed search of the peer-reviewed literature that primarily deals with optical sensors for amino acids and focuses on the use of different type of materials as a sensing platform. Ninety-five papers have been included in the review, majority of which deals with optical sensors. We attempt to systematically classify these contributions based on applications of various chemical and biological scaffolds such as polymers, supramolecular assemblies, nanoparticles, DNA, heparin etc. for the sensing of amino acids. This review identifies that supramolecular assemblies and nanomaterial continue to be commonly used materials to devise sensors for amino acids followed by surfactant assemblies. The broad implications of amino acids in human health and diagnosis have stirred a lot of interest to develop optimized optical detection systems for amino acids in recent years, using different materials based on chemical and biological scaffolds. We have also attempted to highlight the merits and demerits of some of the noteworthy sensor systems to instigate further efforts for constructing amino acids sensor based on unconventional concepts. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Overview of Fiber-Optical Sensors

Science.gov (United States)

Depaula, Ramon P.; Moore, Emery L.

1987-01-01

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

Optical Characterization of Lorentz Force Based CMOS-MEMS Magnetic Field Sensor.

Science.gov (United States)

Dennis, John Ojur; Ahmad, Farooq; Khir, M Haris Bin Md; Bin Hamid, Nor Hisham

2015-07-27

Magnetic field sensors are becoming an essential part of everyday life due to the improvements in their sensitivities and resolutions, while at the same time they have become compact, smaller in size and economical. In the work presented herein a Lorentz force based CMOS-MEMS magnetic field sensor is designed, fabricated and optically characterized. The sensor is fabricated by using CMOS thin layers and dry post micromachining is used to release the device structure and finally the sensor chip is packaged in DIP. The sensor consists of a shuttle which is designed to resonate in the lateral direction (first mode of resonance). In the presence of an external magnetic field, the Lorentz force actuates the shuttle in the lateral direction and the amplitude of resonance is measured using an optical method. The differential change in the amplitude of the resonating shuttle shows the strength of the external magnetic field. The resonance frequency of the shuttle is determined to be 8164 Hz experimentally and from the resonance curve, the quality factor and damping ratio are obtained. In an open environment, the quality factor and damping ratio are found to be 51.34 and 0.00973 respectively. The sensitivity of the sensor is determined in static mode to be 0.034 µm/mT when a current of 10 mA passes through the shuttle, while it is found to be higher at resonance with a value of 1.35 µm/mT at 8 mA current. Finally, the resolution of the sensor is found to be 370.37 µT.

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, where...... the sensitivity can be tuned in the fabrication process. The developed sensor design, simplifies the fabrication process leading to a lower fabrication cost, which can make the all optical pressure sensors more competitive towards their electrical counterpart. The sensor has shown promising results and a linear...... pressure response has been measured with a sensitivity of 0.6nm/bar....

Spatial Frequency Multiplexing of Fiber-Optic Interferometric Refractive Index Sensors Based on Graded-Index Multimode Fibers

Science.gov (United States)

Liu, Li; Gong, Yuan; Wu, Yu; Zhao, Tian; Wu, Hui-Juan; Rao, Yun-Jiang

2012-01-01

Fiber-optic interferometric sensors based on graded-index multimode fibers have very high refractive-index sensitivity, as we previously demonstrated. In this paper, spatial-frequency multiplexing of this type of fiber-optic refractive index sensors is investigated. It is estimated that multiplexing of more than 10 such sensors is possible. In the multiplexing scheme, one of the sensors is used to investigate the refractive index and temperature responses. The fast Fourier transform (FFT) of the combined reflective spectra is analyzed. The intensity of the FFT spectra is linearly related with the refractive index and is not sensitive to the temperature.

An Optical Wavefront Sensor Based on a Double Layer Microlens Array

Directory of Open Access Journals (Sweden)

Hsiang-Chun Wei

2011-10-01

Full Text Available In order to determine light aberrations, Shack-Hartmann optical wavefront sensors make use of microlens arrays (MLA to divide the incident light into small parts and focus them onto image planes. In this paper, we present the design and fabrication of long focal length MLA with various shapes and arrangements based on a double layer structure for optical wavefront sensing applications. A longer focal length MLA could provide high sensitivity in determining the average slope across each microlens under a given wavefront, and spatial resolution of a wavefront sensor is increased by numbers of microlenses across a detector. In order to extend focal length, we used polydimethysiloxane (PDMS above MLA on a glass substrate. Because of small refractive index difference between PDMS and MLA interface (UV-resin, the incident light is less refracted and focused in further distance. Other specific focal lengths could also be realized by modifying the refractive index difference without changing the MLA size. Thus, the wavefront sensor could be improved with better sensitivity and higher spatial resolution.

Planar optical waveguide sensor of ammonia

Science.gov (United States)

Sarkisov, Sergey S.; Curley, Michael J.; Boykin, Courtney; Diggs, Darnell E.; Grote, James G.; Hopkins, Frank K.

2004-12-01

We describe a novel sensor of ammonia based on a planar optical waveguide made of a thin film of polymer polyimide doped with indicator dye bromocresol purple. The film of dye-doped polyimide demonstrated reversible increase of absorption with a peak near 600 nm in response to presence of ammonia in ambient air. Coupling of input and output optic fibers with the waveguide was done by means of coupling prisms or coupling grooves. The latter configuration has the advantage of low cost, less sensitivity to temperature variation, and the possibility of coupling from both sides of the waveguide. Special experimental setup was built to test the sensor. It included test gas chamber with sealed optic fiber feed-throughs, gas filling line, laser source, photodetector, and signal processing hardware and software. The sensor was capable of detecting 100 ppm of ammonia in air within 8 seconds. Further increase of sensitivity can be achieved by adding more dye dopant to the polymer, increase of the length of the waveguide, and suppression of noise. Overexposure of the sensor to more than 5000 ppm of ammonia led to the saturation of the polymer film and, as a result, significant decrease of sensitivity and increase of the response time. The sensor can be used as low cost component of a distributed optical network of chemical sensors for monitoring presence of hazardous industrial pollutants in air.

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.

Fiber-Optic Surface Temperature Sensor Based on Modal Interference

Directory of Open Access Journals (Sweden)

Frédéric Musin

2016-07-01

Full Text Available Spatially-integrated surface temperature sensing is highly useful when it comes to controlling processes, detecting hazardous conditions or monitoring the health and safety of equipment and people. Fiber-optic sensing based on modal interference has shown great sensitivity to temperature variation, by means of cost-effective image-processing of few-mode interference patterns. New developments in the field of sensor configuration, as described in this paper, include an innovative cooling and heating phase discrimination functionality and more precise measurements, based entirely on the image processing of interference patterns. The proposed technique was applied to the measurement of the integrated surface temperature of a hollow cylinder and compared with a conventional measurement system, consisting of an infrared camera and precision temperature probe. As a result, the optical technique is in line with the reference system. Compared with conventional surface temperature probes, the optical technique has the following advantages: low heat capacity temperature measurement errors, easier spatial deployment, and replacement of multiple angle infrared camera shooting and the continuous monitoring of surfaces that are not visually accessible.

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.

Cost-Effective Brillouin Optical Time-Domain Analysis Sensor Using a Single Optical Source and Passive Optical Filtering

Directory of Open Access Journals (Sweden)

H. Iribas

2016-01-01

Full Text Available We present a simplified configuration for distributed Brillouin optical time-domain analysis sensors that aims to reduce the cost of the sensor by reducing the number of components required for the generation of the two optical waves involved in the sensing process. The technique is based on obtaining the pump and probe waves by passive optical filtering of the spectral components generated in a single optical source that is driven by a pulsed RF signal. The optical source is a compact laser with integrated electroabsorption modulator and the optical filters are based on fiber Bragg gratings. Proof-of-concept experiments demonstrate 1 m spatial resolution over a 20 km sensing fiber with a 0.9 MHz precision in the measurement of the Brillouin frequency shift, a performance similar to that of much more complex setups. Furthermore, we discuss the factors limiting the sensor performance, which are basically related to residual spectral components in the filtering process.

Monitoring of Moisture in Transformer Oil Using Optical Fiber as Sensor

OpenAIRE

S. Laskar; S. Bordoloi

2013-01-01

This paper describes an optical fiber sensor and temperature sensor-based instrumentation system to measure the moisture content in transformer oil. The sensor system consists of (i) Diode Laser Source, (ii) a bare and bent multimode fiber as sensor probe, (iii) an LDR as detector, (iv) LM35-based temperature sensor, and (v) microcontroller system having a trained ANN for processing and calibration. The bare and bent optical fiber sensor and the temperature sensor LM35 are used to provide the...

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.

Lightweight Fiber Optic Gas Sensor for Monitoring Regenerative Food Production

Science.gov (United States)

Schmidlin, Edward; Goswami, Kisholoy

1995-01-01

In this final report, Physical Optics Corporation (POC) describes its development of sensors for oxygen, carbon dioxide, and relative humidity. POC has constructed a phase fluorometer that can detect oxygen over the full concentration range from 0 percent to 100 percent. Phase-based measurements offer distinct advantages, such as immunity to source fluctuation, photobleaching, and leaching. All optics, optoelectronics, power supply, and the printed circuit board are included in a single box; the only external connections to the fluorometer are the optical fiber sensor and a power cord. The indicator-based carbon dioxide sensor is also suitable for short-term and discrete measurements over the concentration range from 0 percent to 100 percent. The optical fiber-based humidity sensor contains a porous core for direct interaction of the light beam with water vapor within fiber pores; the detection range for the humidity sensor is 10 percent to 100 percent, and response time is under five minutes. POC is currently pursuing the commercialization of these oxygen and carbon dioxide sensors for environmental applications.

Fibre optical measuring network based on quasi-distributed amplitude sensors for detecting deformation loads

International Nuclear Information System (INIS)

Kul'chin, Yurii N; Kolchinskiy, V A; Kamenev, O T; Petrov, Yu S

2013-01-01

A new design of a sensitive element for a fibre optical sensor of deformation loads is proposed. A distributed fibre optical measuring network, aimed at determining both the load application point and the load mass, has been developed based on these elements. It is shown that neural network methods of data processing make it possible to combine quasi-distributed amplitude sensors of different types into a unified network. The results of the experimental study of a breadboard of a fibre optical measuring network are reported, which demonstrate successful reconstruction of the trajectory of a moving object (load) with a spatial resolution of 8 cm, as well as the load mass in the range of 1 – 10 kg with a sensitivity of 0.043 kg -1 . (laser optics 2012)

Optical fibre sensor for the measurement of ozone

International Nuclear Information System (INIS)

O'Keeffe, S; Dooly, G; Fitzpatrick, C; Lewis, E

2005-01-01

The use of optical fibres for the measurement of ozone based on the optical absorption of both UV light at 254nm and visible light at 600nm is investigated and tested. Calculations based on the Beer-Lambert Law are also presented to demonstrate the high resolution of the UV based sensor in determining the concentration of ozone in the range of 0 mg/litre to 1mg/litre and the ability of the visible based sensor to measure high concentrations over a wide range

A new fiber optic sensor for inner surface roughness measurement

Science.gov (United States)

Xu, Xiaomei; Liu, Shoubin; Hu, Hong

2009-11-01

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

Highly sensitive fiber-optic oxygen sensor based on palladium tetrakis (4-carboxyphenyl)porphyrin doped in ormosil

International Nuclear Information System (INIS)

Chu, Cheng-Shane; Chuang, Chih-Yung

2014-01-01

A simple, low-cost technique for fabrication of highly sensitive fiber-optic oxygen sensor is described. An organically modified silicate (ORMOSIL) as a matrix for the fabrication of oxygen sensing film was produced. The technique is based on coating the end of a plastic optical fiber with ormosil composite xerogel film sequestered with luminophore palladium (II) meso-tetra(4-carboxyphenyl)porphyrin (PdTCPP) prepared by a sol–gel process. The composite xerogel studied is tetraethylorthosilane (TEOS)/n-octyltriethoxysilane (Octyl-triEOS). Result shows that, expect for PdTCPP-doped TEOS/Octyl-triEOS composite xerogel show the high sensitivity and linear Stern–Volmer relationship which indicate the homogenous environment of the luminophore. The sensitivity of the optical oxygen sensor is quantified in terms of the ratio I N2 /I O2 , where I N2 and I O2 represent the detected fluorescence intensities in pure nitrogen and pure oxygen environments, respectively. The experimental result reveals that the PdTCPP-doped TEOS/Octyl-triEOS oxygen sensor has sensitivity of 153. - Highlights: • A simple, low-cost technique for fabrication of highly sensitive fiber-optic oxygen sensor is described. • ORMOSIL was produced to serve as a matrix for the fabrication of oxygen sensing film. • The fiber-optic oxygen sensor has sensitivity of I N2 /I 100O2 =153. • The stable and reproducible signals were obtained with the fiber-optic oxygen sensor

Optical fiber pressure sensor based on fiber Bragg grating

Science.gov (United States)

Song, Dongcao

In oil field, it is important to measure the high pressure and temperature for down-hole oil exploration and well-logging, the available traditional electronic sensor is challenged due to the harsh, flammable environment. Recently, applications based on fiber Bragg grating (FBG) sensor in the oil industry have become a popular research because of its distinguishing advantages such as electrically passive operation, immunity to electromagnetic interference, high resolution, insensitivity to optical power fluctuation etc. This thesis is divided into two main sections. In the first section, the design of high pressure sensor based on FBG is described. Several sensing elements based on FBG for high pressure measurements have been proposed, for example bulk-modulus or free elastic modulus. But the structure of bulk-modulus and free elastic modulus is relatively complex and not easy to fabricate. In addition, the pressure sensitivity is not high and the repeatability of the structure has not been investigated. In this thesis, a novel host material of carbon fiber laminated composite (CFLC) for high pressure sensing is proposed. The mechanical characteristics including principal moduli in three directions and the shape repeatability are investigated. Because of it's Young's modulus in one direction and anisotropic characteristics, the pressure sensor made by CFLC has excellent sensitivity. This said structure can be used in very high pressure measurement due to carbon fiber composite's excellent shape repetition even under high pressure. The experimental results show high pressure sensitivity of 0.101nm/MPa and high pressure measurement up to 70MPa. A pressure sensor based on CFLC and FBG with temperature compensation has been designed. In the second section, the design of low pressure sensor based on FBG is demonstrated. Due to the trade off between measurement range and sensitivity, a sensor for lower pressure range needs more sensitivity. A novel material of carbon

FDTD-based optical simulations methodology for CMOS image sensors pixels architecture and process optimization

Science.gov (United States)

Hirigoyen, Flavien; Crocherie, Axel; Vaillant, Jérôme M.; Cazaux, Yvon

2008-02-01

This paper presents a new FDTD-based optical simulation model dedicated to describe the optical performances of CMOS image sensors taking into account diffraction effects. Following market trend and industrialization constraints, CMOS image sensors must be easily embedded into even smaller packages, which are now equipped with auto-focus and short-term coming zoom system. Due to miniaturization, the ray-tracing models used to evaluate pixels optical performances are not accurate anymore to describe the light propagation inside the sensor, because of diffraction effects. Thus we adopt a more fundamental description to take into account these diffraction effects: we chose to use Maxwell-Boltzmann based modeling to compute the propagation of light, and to use a software with an FDTD-based (Finite Difference Time Domain) engine to solve this propagation. We present in this article the complete methodology of this modeling: on one hand incoherent plane waves are propagated to approximate a product-use diffuse-like source, on the other hand we use periodic conditions to limit the size of the simulated model and both memory and computation time. After having presented the correlation of the model with measurements we will illustrate its use in the case of the optimization of a 1.75μm pixel.

CMOS image sensor-based implantable glucose sensor using glucose-responsive fluorescent hydrogel.

Science.gov (United States)

Tokuda, Takashi; Takahashi, Masayuki; Uejima, Kazuhiro; Masuda, Keita; Kawamura, Toshikazu; Ohta, Yasumi; Motoyama, Mayumi; Noda, Toshihiko; Sasagawa, Kiyotaka; Okitsu, Teru; Takeuchi, Shoji; Ohta, Jun

2014-11-01

A CMOS image sensor-based implantable glucose sensor based on an optical-sensing scheme is proposed and experimentally verified. A glucose-responsive fluorescent hydrogel is used as the mediator in the measurement scheme. The wired implantable glucose sensor was realized by integrating a CMOS image sensor, hydrogel, UV light emitting diodes, and an optical filter on a flexible polyimide substrate. Feasibility of the glucose sensor was verified by both in vitro and in vivo experiments.

Integrated optics nano-opto-fluidic sensor based on whispering gallery modes for picoliter volume refractometry

NARCIS (Netherlands)

Gilardi, G.; Beccherelli, R.

2013-01-01

We propose and numerically investigate an integrated optics refractometric nano-opto-fluidic sensor based on whispering gallery modes in sapphire microspheres. A measurand fluid is injected in a micromachined reservoir defined in between the microsphere and an optical waveguide. The wavelength shift

Damage and failure detection of composites using optical fiber vibration sensor

International Nuclear Information System (INIS)

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

2001-01-01

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

Fabrication and evaluation of hybrid silica/polymer optical fiber sensors for large strain measurement

Science.gov (United States)

Huang, Haiying

2007-04-01

Silica-based optical fiber sensors are widely used in structural health monitoring systems for strain and deflection measurement. One drawback of silica-based optical fiber sensors is their low strain toughness. In general, silica-based optical fiber sensors can only reliably measure strains up to 2%. Recently, polymer optical fiber sensors have been employed to measure large strain and deflection. Due to their high optical losses, the length of the polymer optical fibers is limited to 100 meters. In this paper, we present a novel economical technique to fabricate hybrid silica/polymer optical fiber strain sensors for large strain measurement. First, stress analysis of a surface-mounted optical fiber sensor is performed to understand the load distribution between the host structure and the optical fiber in relation to their mechanical properties. Next, the procedure of fabricating a polymer sensing element between two optical fibers is explained. The experimental set-up and the components used in the fabrication process are described in details. Mechanical testing results of the fabricated silica/polymer optical fiber strain sensor are presented.

Signal transmission in a human body medium-based body sensor network using a Mach-Zehnder electro-optical sensor.

Science.gov (United States)

Song, Yong; Hao, Qun; Zhang, Kai; Wang, Jingwen; Jin, Xuefeng; Sun, He

2012-11-30

The signal transmission technology based on the human body medium offers significant advantages in Body Sensor Networks (BSNs) used for healthcare and the other related fields. In previous works we have proposed a novel signal transmission method based on the human body medium using a Mach-Zehnder electro-optical (EO) sensor. In this paper, we present a signal transmission system based on the proposed method, which consists of a transmitter, a Mach-Zehnder EO sensor and a corresponding receiving circuit. Meanwhile, in order to verify the frequency response properties and determine the suitable parameters of the developed system, in-vivo measurements have been implemented under conditions of different carrier frequencies, baseband frequencies and signal transmission paths. Results indicate that the proposed system will help to achieve reliable and high speed signal transmission of BSN based on the human body medium.

Integrated-optic current sensors with a multimode interference waveguide device.

Science.gov (United States)

Kim, Sung-Moon; Chu, Woo-Sung; Kim, Sang-Guk; Oh, Min-Cheol

2016-04-04

Optical current sensors based on polarization-rotated reflection interferometry are demonstrated using polymeric integrated optics and various functional optical waveguide devices. Interferometric sensors normally require bias feedback control for maintaining the operating point, which increases the cost. In order to resolve this constraint of feedback control, a multimode interference (MMI) waveguide device is integrated onto the current-sensor optical chip in this work. From the multiple outputs of the MMI, a 90° phase-shifted transfer function is obtained. Using passive quadrature demodulation, we demonstrate that the sensor could maintain the output signal regardless of the drift in the operating bias-point.

Fiber Optic Displacement Sensor for Measuring Cholesterol Concentration

Directory of Open Access Journals (Sweden)

Moh. Budiyanto

2017-11-01

Full Text Available A simple design of a cholesterol concentration detection is proposed and demonstrated using a fiber optic displacement sensor based on an intensity modulation technique. The proposed sensor uses a bundled plastic optical fiber (POF as a probe in conjunction with a flat mirror as a target. It is obtained that the peak voltage reduces with increasing cholesterol concentration. The sensor is capable of measuring the cholesterol concentration ranging from 0 to 300 ppm in a distilled water with a measured sensitivity of 0.01 mV/ppm, a linearity of more than 99.62 % and a resolution of 3.9188 ppm. The proposed sensor also shows a high degree of stability and good repeatability. The simplicity of design, accuracy, flexible dynamic range, and the low cost of fabrication are favorable attributes of the sensor and beneficial for real- field applications. Fiber optic sensors

Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution

Directory of Open Access Journals (Sweden)

Chia-Chin Chiang

2013-01-01

Full Text Available An optical fiber solution-concentration sensor based on whispering gallery mode (WGM is proposed in this paper. The WGM solution-concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and an R2 linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution-concentration sensing.

A fiber-optic sensor based on no-core fiber and Faraday rotator mirror structure

Science.gov (United States)

Lu, Heng; Wang, Xu; Zhang, Songling; Wang, Fang; Liu, Yufang

2018-05-01

An optical fiber sensor based on the single-mode/no-core/single-mode (SNS) core-offset technology along with a Faraday rotator mirror structure has been proposed and experimentally demonstrated. A transverse optical field distribution of self-imaging has been simulated and experimental parameters have been selected under theoretical guidance. Results of the experiments demonstrate that the temperature sensitivity of the sensor is 0.0551 nm/°C for temperatures between 25 and 80 °C, and the correlation coefficient is 0.99582. The concentration sensitivity of the device for sucrose and glucose solutions was found to be as high as 12.5416 and 6.02248 nm/(g/ml), respectively. Curves demonstrating a linear fit between wavelength shift and solution concentration for three different heavy metal solutions have also been derived on the basis of experimental results. The proposed fiber-optic sensor design provides valuable guidance for the measurement of concentration and temperature.

Fiber-optic seismic sensor

International Nuclear Information System (INIS)

Finch, G. W.; Udd, E.

1985-01-01

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

Measurement of Temperature and Relative Humidity with Polymer Optical Fiber Sensors Based on the Induced Stress-Optic Effect

Science.gov (United States)

Pontes, Maria José

2018-01-01

This paper presents a system capable of measuring temperature and relative humidity with polymer optical fiber (POF) sensors. The sensors are based on variations of the Young’s and shear moduli of the POF with variations in temperature and relative humidity. The system comprises two POFs, each with a predefined torsion stress that resulted in a variation in the fiber refractive index due to the stress-optic effect. Because there is a correlation between stress and material properties, the variation in temperature and humidity causes a variation in the fiber’s stress, which leads to variations in the fiber refractive index. Only two photodiodes comprise the sensor interrogation, resulting in a simple and low-cost system capable of measuring humidity in the range of 5–97% and temperature in the range of 21–46 °C. The root mean squared errors (RMSEs) between the proposed sensors and the reference were 1.12 °C and 1.36% for the measurements of temperature and relative humidity, respectively. In addition, fiber etching resulted in a sensor with a 2 s response time for a relative humidity variation of 10%, which is one of the lowest recorded response times for intrinsic POF humidity sensors. PMID:29558387

An Embeddable Strain Sensor with 30 Nano-Strain Resolution Based on Optical Interferometry

Directory of Open Access Journals (Sweden)

Chen Zhu

2018-04-01

Full Text Available A cost-effective, robust and embeddable optical interferometric strain sensor with nanoscale strain resolution is presented in this paper. The sensor consists of an optical fiber, a quartz rod with one end coated with a thin gold layer, and two metal shells employed to transfer the strain and orient and protect the optical fiber and the quartz rod. The optical fiber endface, combining with the gold-coated surface, forms an extrinsic Fabry–Perot interferometer. The sensor was firstly calibrated, and the result showed that our prototype sensor could provide a measurement resolution of 30 nano-strain (nε and a sensitivity of 10.01 µε/µm over a range of 1000 µε. After calibration of the sensor, the shrinkage strain of a cubic brick of mortar in real time during the drying process was monitored. The strain sensor was compared with a commercial linear variable displacement transducer, and the comparison results in four weeks demonstrated that our sensor had much higher measurement resolution and gained more detailed and useful information. Due to the advantages of the extremely simple, robust and cost-effective configuration, it is believed that the sensor is significantly beneficial to practical applications, especially for structural health monitoring.

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

Science.gov (United States)

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

2014-08-01

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

A novel fiber-optic temperature sensor based on high temperature-dependent optical properties of ZnO film on sapphire fiber-ending

International Nuclear Information System (INIS)

Cai Pinggen; Zhen Dong; Xu Xiaojun; Liu Yulin; Chen Naibo; Wei Gaorao; Sui Chenghua

2010-01-01

We report the growth of high-quality thin films of ZnO via an electron-beam evaporation technique. Studies of the transmittance spectra have revealed a sharp optical absorption edge and a significant redshift. After annealing at 673 K, the ZnO films again demonstrated a sharp absorption edge in a manner similar to the as-deposited samples. This illustrates the excellent thermal stability of the thin films and, as such, demonstrates their potential as fiber-optic temperature sensors. Utilizing the influence of optical absorption spectra at different temperatures, a novel fiber-optic temperature sensor based on this material has been designed and tested. This technique could offer a simple, robust and cost-effective method to be used in high temperature sensing applications.

Optical Flow in a Smart Sensor Based on Hybrid Analog-Digital Architecture

Directory of Open Access Journals (Sweden)

Pablo Guzmán

2010-03-01

Full Text Available The purpose of this study is to develop a motion sensor (delivering optical flow estimations using a platform that includes the sensor itself, focal plane processing resources, and co-processing resources on a general purpose embedded processor. All this is implemented on a single device as a SoC (System-on-a-Chip. Optical flow is the 2-D projection into the camera plane of the 3-D motion information presented at the world scenario. This motion representation is widespread well-known and applied in the science community to solve a wide variety of problems. Most applications based on motion estimation require work in real-time; hence, this restriction must be taken into account. In this paper, we show an efficient approach to estimate the motion velocity vectors with an architecture based on a focal plane processor combined on-chip with a 32 bits NIOS II processor. Our approach relies on the simplification of the original optical flow model and its efficient implementation in a platform that combines an analog (focal-plane and digital (NIOS II processor. The system is fully functional and is organized in different stages where the early processing (focal plane stage is mainly focus to pre-process the input image stream to reduce the computational cost in the post-processing (NIOS II stage. We present the employed co-design techniques and analyze this novel architecture. We evaluate the system’s performance and accuracy with respect to the different proposed approaches described in the literature. We also discuss the advantages of the proposed approach as well as the degree of efficiency which can be obtained from the focal plane processing capabilities of the system. The final outcome is a low cost smart sensor for optical flow computation with real-time performance and reduced power consumption that can be used for very diverse application domains.

Optical Flow in a Smart Sensor Based on Hybrid Analog-Digital Architecture

Science.gov (United States)

Guzmán, Pablo; Díaz, Javier; Agís, Rodrigo; Ros, Eduardo

2010-01-01

The purpose of this study is to develop a motion sensor (delivering optical flow estimations) using a platform that includes the sensor itself, focal plane processing resources, and co-processing resources on a general purpose embedded processor. All this is implemented on a single device as a SoC (System-on-a-Chip). Optical flow is the 2-D projection into the camera plane of the 3-D motion information presented at the world scenario. This motion representation is widespread well-known and applied in the science community to solve a wide variety of problems. Most applications based on motion estimation require work in real-time; hence, this restriction must be taken into account. In this paper, we show an efficient approach to estimate the motion velocity vectors with an architecture based on a focal plane processor combined on-chip with a 32 bits NIOS II processor. Our approach relies on the simplification of the original optical flow model and its efficient implementation in a platform that combines an analog (focal-plane) and digital (NIOS II) processor. The system is fully functional and is organized in different stages where the early processing (focal plane) stage is mainly focus to pre-process the input image stream to reduce the computational cost in the post-processing (NIOS II) stage. We present the employed co-design techniques and analyze this novel architecture. We evaluate the system’s performance and accuracy with respect to the different proposed approaches described in the literature. We also discuss the advantages of the proposed approach as well as the degree of efficiency which can be obtained from the focal plane processing capabilities of the system. The final outcome is a low cost smart sensor for optical flow computation with real-time performance and reduced power consumption that can be used for very diverse application domains. PMID:22319283

Compound parabolic concentrator optical fiber tip for FRET-based fluorescent sensors

DEFF Research Database (Denmark)

Hassan, Hafeez Ul; Nielsen, Kristian; Aasmul, Soren

2015-01-01

The Compound Parabolic Concentrator (CPC) optical fiber tip shape has been proposed for intensity based fluorescent sensors working on the principle of FRET (Förster Resonance Energy Transfer). A simple numerical Zemax model has been used to optimize the CPC tip geometry for a step-index multimode...... polymer optical fiber for an excitation and emission wavelength of 550 nm and 650nm, respectively. The model suggests an increase of a factor of 1.6 to 4 in the collected fluorescent power for an ideal CPC tip, as compared to the plane-cut fiber tip for fiber lengths between 5 and 45mm...

Temperature measurement and damage detection in concrete beams exposed to fire using PPP-BOTDA based fiber optic sensors

Science.gov (United States)

Bao, Yi; Hoehler, Matthew S.; Smith, Christopher M.; Bundy, Matthew; Chen, Genda

2017-10-01

In this study, Brillouin scattering-based distributed fiber optic sensor is implemented to measure temperature distributions and detect cracks in concrete structures subjected to fire for the first time. A telecommunication-grade optical fiber is characterized as a high temperature sensor with pulse pre-pump Brillouin optical time domain analysis (PPP-BODTA), and implemented to measure spatially-distributed temperatures in reinforced concrete beams in fire. Four beams were tested to failure in a natural gas fueled compartment fire, each instrumented with one fused silica, single-mode optical fiber as a distributed sensor and four thermocouples. Prior to concrete cracking, the distributed temperature was validated at locations of the thermocouples by a relative difference of less than 9%. The cracks in concrete can be identified as sharp peaks in the temperature distribution since the cracks are locally filled with hot air. Concrete cracking did not affect the sensitivity of the distributed sensor but concrete spalling broke the optical fiber loop required for PPP-BOTDA measurements.

Surface plasmon resonance based optical fiber riboflavin sensor by using molecularly imprinted gel

Science.gov (United States)

Verma, Roli; Gupta, Banshi D.

2013-05-01

We report the fabrication and characterization of surface plasmon resonance (SPR) based optical fiber riboflavin/vitamin B2 sensor using combination of colloidal crystal templating and molecularly imprinted gel. The sensor works on spectral interrogation method. The operating range of the sensor lies from 0 μg/ml to 320 μg/ml, the suitable amount of intakes of riboflavin recommended for different age group. The SPR spectra show blue shift with increasing concentration of riboflavin, which is due to the interaction of riboflavin molecule over specific binding sites caused by molecular imprinting. The present sensor has many advantageous features such as fast response, small probe size, low cost and can be used for remote/online monitoring.

Intense transient electric field sensor based on the electro-optic effect of LiNbO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Yang, Qing, E-mail: yangqing@cqu.edu.cn; Sun, Shangpeng; Han, Rui; Sima, Wenxia; Liu, Tong [State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Shapingba District, Chongqing, 400044 (China)

2015-10-15

Intense transient electric field measurements are widely applied in various research areas. An optical intense E-field sensor for time-domain measurements, based on the electro-optic effect of lithium niobate, has been studied in detail. Principles and key issues in the design of the sensor are presented. The sensor is insulated, small in size (65 mm × 15 mm × 15 mm), and suitable for high-intensity (<801 kV/m) electric field measurements over a wide frequency band (10 Hz–10 MHz). The input/output characteristics of the sensor were obtained and the sensor calibrated. Finally, an application using this sensor in testing laboratory lightning impulses and in measuring transient electric fields during switch-on of a disconnector confirmed that the sensor is expected to find widespread use in transient intense electric field measurement applications.

Plasmonic Optical Fiber Sensor Based on Double Step Growth of Gold Nano-Islands.

Science.gov (United States)

de Almeida, José M M M; Vasconcelos, Helena; Jorge, Pedro A S; Coelho, Luis

2018-04-20

It is presented the fabrication and characterization of optical fiber sensors for refractive index measurement based on localized surface plasmon resonance (LSPR) with gold nano-islands obtained by single and by repeated thermal dewetting of gold thin films. Thin films of gold deposited on silica (SiO₂) substrates and produced by different experimental conditions were analyzed by Scanning Electron Microscope/Dispersive X-ray Spectroscopy (SEM/EDS) and optical means, allowing identifying and characterizing the formation of nano-islands. The wavelength shift sensitivity to the surrounding refractive index of sensors produced by single and by repeated dewetting is compared. While for the single step dewetting, a wavelength shift sensitivity of ~60 nm/RIU was calculated, for the repeated dewetting, a value of ~186 nm/RIU was obtained, an increase of more than three times. It is expected that through changing the fabrication parameters and using other fiber sensor geometries, higher sensitivities may be achieved, allowing, in addition, for the possibility of tuning the plasmonic frequency.

Plasmonic Optical Fiber Sensor Based on Double Step Growth of Gold Nano-Islands

Science.gov (United States)

Vasconcelos, Helena

2018-01-01

It is presented the fabrication and characterization of optical fiber sensors for refractive index measurement based on localized surface plasmon resonance (LSPR) with gold nano-islands obtained by single and by repeated thermal dewetting of gold thin films. Thin films of gold deposited on silica (SiO2) substrates and produced by different experimental conditions were analyzed by Scanning Electron Microscope/Dispersive X-ray Spectroscopy (SEM/EDS) and optical means, allowing identifying and characterizing the formation of nano-islands. The wavelength shift sensitivity to the surrounding refractive index of sensors produced by single and by repeated dewetting is compared. While for the single step dewetting, a wavelength shift sensitivity of ~60 nm/RIU was calculated, for the repeated dewetting, a value of ~186 nm/RIU was obtained, an increase of more than three times. It is expected that through changing the fabrication parameters and using other fiber sensor geometries, higher sensitivities may be achieved, allowing, in addition, for the possibility of tuning the plasmonic frequency. PMID:29677108

Aviation Fuel Gauging Sensor Utilizing Multiple Diaphragm Sensors Incorporating Polymer Optical Fiber Bragg Gratings

DEFF Research Database (Denmark)

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

2016-01-01

A high-performance fuel gauging sensor is described that uses five diaphragm-based pressure sensors, which are monitored using a linear array of polymer optical fiber Bragg gratings. The sensors were initially characterized using water, revealing a sensitivity of 98 pm/cm for four of the sensors...... of sensors manufactured with a polyurethane-based diaphragm showed no measurable deterioration over a three month period immersed in fuel. These sensors exhibited a sensitivity of 39 pm/cm, which is less than the silicone rubber devices due to the stiffer nature of the polyurethane material used....

Design and realization of temperature measurement system based on optical fiber temperature sensor for wireless power transfer

Science.gov (United States)

Chen, Xi; Zeng, Shuang; Liu, Xiulan; Jin, Yuan; Li, Xianglong; Wang, Xiaochen

2018-02-01

The electric vehicles (EV) have become accepted by increasing numbers of people for the environmental-friendly advantages. A novel way to charge the electric vehicles is through wireless power transfer (WPT). The wireless power transfer is a high power transfer system. The high currents flowing through the transmitter and receiver coils increasing temperature affects the safety of person and charging equipment. As a result, temperature measurement for wireless power transfer is needed. In this paper, a temperature measurement system based on optical fiber temperature sensors for electric vehicle wireless power transfer is proposed. Initially, the thermal characteristics of the wireless power transfer system are studied and the advantages of optical fiber sensors are analyzed. Then the temperature measurement system based on optical fiber temperature sensor is designed. The system consists of optical subsystem, data acquisition subsystem and data processing subsystem. Finally, the system is tested and the experiment result shows that the system can realize 1°C precision and can acquire real-time temperature distribution of the coils, which can meet the requirement of the temperature measuring for wireless power transfer.

Optical fibre luminescence sensor for real-time LDR brachytherapy dosimetry

Science.gov (United States)

Woulfe, P.; O'Keeffe, S.; Sullivan, F. J.

2018-02-01

An optical fibre sensor for monitoring low dose radiation is presented. The sensor is based on a scintillation material embedded within the optical fibre core, which emits visible light when exposed to low level ionising radiation. The incident level of ionising radiation can be determined by analysing the optical emission. An optical fibre sensor is developed, based on radioluminescence whereby radiation sensitive scintillation material, terbium doped gadolinium oxysulphide (Gd2O2S:Tb), is embedded in a cavity of 700μm of a 1mm plastic optical fibre. The sensor is designed for in-vivo monitoring of the radiation dose during radio-active seed implantation for low dose rate (LDR) brachytherapy, in prostate cancer treatment, providing radiation oncologists with real-time information of the radiation dose to the target area and/or nearby organs at risk (OARs). The radiation from the brachytherapy seeds causes emission of visible light from the scintillation material through the process of radioluminescence, which penetrates the fibre, propagating along the optical fibre for remote detection using a multi-pixel photon counter. The sensor demonstrates a high sensitivity to 0.397mCi of Iodine125, the radioactive source most commonly used in brachytherapy for treating prostate cancer.

Multifunctional optical sensor

NARCIS (Netherlands)

2010-01-01

The invention relates to a multifunctional optical sensor, having at least 2 areas which independently react to different input parameters, the sensor comprising a substrate and a polymeric layer comprising polymerized liquid crystal monomers having an ordered morphology, wherein the color, the

Novel Highly Sensitive Protein Sensors Based on Tapered Optical Fibres Modified with Au-Based Nanocoatings

Directory of Open Access Journals (Sweden)

Aitor Urrutia

2016-01-01

Full Text Available Novel protein sensors based on tapered optical fibres modified with Au coatings deposited using two different procedures are proposed. Au-based coatings are deposited onto a nonadiabatic tapered optical fibre using (i a novel facile method composed of layer-by-layer deposition consisting of polycation (poly(allylamine hydrochloride, PAH and negatively charged SiO2 nanoparticles (NPs followed by the deposition of the charged Au NPs and (ii the sputtering technique. The Au NPs and Au thin film surfaces are then modified with biotin in order to bind streptavidin (SV molecules and detect them. The sensing principle is based on the sensitivity of the transmission spectrum of the device to changes in the refractive index of the coatings induced by the SV binding to the biotin. Both sensors showed high sensitivity to SV, with the lowest measured concentration levels below 2.5 nM. The calculated binding constant for the biotin-SV pair was 2.2×10-11 M−1 when a tapered fibre modified with the LbL method was used, with a limit of detection (LoD of 271 pM. The sensor formed using sputtering had a binding constant of 1.01×10-10 M−1 with a LoD of 806 pM. These new structures and their simple fabrication technique could be used to develop other biosensors.

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

Science.gov (United States)

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

2018-05-01

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

Silicon-Nitride-based Integrated Optofluidic Biochemical Sensors using a Coupled-Resonator Optical Waveguide

Directory of Open Access Journals (Sweden)

Jiawei eWANG

2015-04-01

Full Text Available Silicon nitride (SiN is a promising material platform for integrating photonic components and microfluidic channels on a chip for label-free, optical biochemical sensing applications in the visible to near-infrared wavelengths. The chip-scale SiN-based optofluidic sensors can be compact due to a relatively high refractive index contrast between SiN and the fluidic medium, and low-cost due to the complementary metal-oxide-semiconductor (CMOS-compatible fabrication process. Here, we demonstrate SiN-based integrated optofluidic biochemical sensors using a coupled-resonator optical waveguide (CROW in the visible wavelengths. The working principle is based on imaging in the far field the out-of-plane elastic-light-scattering patterns of the CROW sensor at a fixed probe wavelength. We correlate the imaged pattern with reference patterns at the CROW eigenstates. Our sensing algorithm maps the correlation coefficients of the imaged pattern with a library of calibrated correlation coefficients to extract a minute change in the cladding refractive index. Given a calibrated CROW, our sensing mechanism in the spatial domain only requires a fixed-wavelength laser in the visible wavelengths as a light source, with the probe wavelength located within the CROW transmission band, and a silicon digital charge-coupled device (CCD / CMOS camera for recording the light scattering patterns. This is in sharp contrast with the conventional optical microcavity-based sensing methods that impose a strict requirement of spectral alignment with a high-quality cavity resonance using a wavelength-tunable laser. Our experimental results using a SiN CROW sensor with eight coupled microrings in the 680nm wavelength reveal a cladding refractive index change of ~1.3 × 10^-4 refractive index unit (RIU, with an average sensitivity of ~281 ± 271 RIU-1 and a noise-equivalent detection limit (NEDL of 1.8 ×10^-8 RIU ~ 1.0 ×10^-4 RIU across the CROW bandwidth of ~1 nm.

Optical Sensor of Thermal Gas Flow Based on Fiber Bragg Grating

Directory of Open Access Journals (Sweden)

Xu Jiang

2017-02-01

Full Text Available This paper aims at solving the problem of explosion proof in measurement of thermal gas flow using electronic sensor by presenting a new type of flow sensor by optical fiber heating. A measuring unit based on fiber Bragg grating (FBG for fluid temperature and a unit for heat dissipation are designed to replace the traditional electronic sensors. The light in C band from the amplified spontaneous emission (ASE light source is split, with one part used to heat the absorbing coating and the other part used in the signal processing unit. In the heating unit, an absorbing coating is introduced to replace the traditional resistance heating module to minimize the risk of explosion. The measurement results demonstrate a fine consistency between the flow and temperature difference in simulation. The method to enhance the measurement resolution of flow is also discussed.

Passive (self-powered) fiber-optic sensors

International Nuclear Information System (INIS)

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

1992-01-01

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

Toward Optical Sensors: Review and Applications

International Nuclear Information System (INIS)

Sabri, Naseer; Aljunid, S A; Ahmad, R B; Salim, M S; Kamaruddin, R

2013-01-01

Recent advances in fiber optics (FOs) and the numerous advantages of light over electronic systems have boosted the utility and demand for optical sensors in various military, industry and social fields. Environmental and atmospheric monitoring, earth and space sciences, industrial chemical processing and biotechnology, law enforcement, digital imaging, scanning, and printing are exemplars of them. The ubiquity of photonic technologies could drive down prices which reduced the cost of optical fibers and lasers. Fiber optic sensors (FOSs) offer a wide spectrum of advantages over traditional sensing systems, such as small size and longer lifetime. Immunity to electromagnetic interference, amenability to multiplexing, and high sensitivity make FOs the sensor technology of choice in several fields, including the healthcare and aerospace sectors. FOSs show reliable and rigid sensing tasks over conventional electrical and electronic sensors. This paper presents an executive review of optical fiber sensors and the most beneficial applications.

Toward Optical Sensors: Review and Applications

Science.gov (United States)

Sabri, Naseer; Aljunid, S. A.; Salim, M. S.; Ahmad, R. B.; Kamaruddin, R.

2013-04-01

Recent advances in fiber optics (FOs) and the numerous advantages of light over electronic systems have boosted the utility and demand for optical sensors in various military, industry and social fields. Environmental and atmospheric monitoring, earth and space sciences, industrial chemical processing and biotechnology, law enforcement, digital imaging, scanning, and printing are exemplars of them. The ubiquity of photonic technologies could drive down prices which reduced the cost of optical fibers and lasers. Fiber optic sensors (FOSs) offer a wide spectrum of advantages over traditional sensing systems, such as small size and longer lifetime. Immunity to electromagnetic interference, amenability to multiplexing, and high sensitivity make FOs the sensor technology of choice in several fields, including the healthcare and aerospace sectors. FOSs show reliable and rigid sensing tasks over conventional electrical and electronic sensors. This paper presents an executive review of optical fiber sensors and the most beneficial applications.

Distributed Long-Gauge Optical Fiber Sensors Based Self-Sensing FRP Bar for Concrete Structure

OpenAIRE

Tang, Yongsheng; Wu, Zhishen

2016-01-01

Brillouin scattering-based distributed optical fiber (OF) sensing technique presents advantages for concrete structure monitoring. However, the existence of spatial resolution greatly decreases strain measurement accuracy especially around cracks. Meanwhile, the brittle feature of OF also hinders its further application. In this paper, the distributed OF sensor was firstly proposed as long-gauge sensor to improve strain measurement accuracy. Then, a new type of self-sensing fiber reinforced p...

A review of fiber-optic corrosion sensor in civil engineering

Science.gov (United States)

Luo, Dong; Li, Junnan; Li, Yuanyuan

2018-05-01

Fiber-optical corrosion sensor (FOCS) is the research hotspot of corrosion monitoring sensor in recent years. It has the advantages of lightness, simplicity, anti-electromagnetic interference and distributed measurement, so it has an attractive application prospect. In this paper, the mechanism of metal corrosion is introduced. Several common methods for detecting optical fiber corrosion sensors are presented, and the latest progress of optical fiber corrosion sensors in recent years is described. We need to design a set of sensor devices that can directly monitor the corrosion of reinforcing steel bars directly, and propose a method of time dependent reliability assessment based on monitoring data, so as to form a complete research path.

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

Science.gov (United States)

Glomb, W. L., Jr.

1990-01-01

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

Machine learning enhanced optical distance sensor

Science.gov (United States)

Amin, M. Junaid; Riza, N. A.

2018-01-01

Presented for the first time is a machine learning enhanced optical distance sensor. The distance sensor is based on our previously demonstrated distance measurement technique that uses an Electronically Controlled Variable Focus Lens (ECVFL) with a laser source to illuminate a target plane with a controlled optical beam spot. This spot with varying spot sizes is viewed by an off-axis camera and the spot size data is processed to compute the distance. In particular, proposed and demonstrated in this paper is the use of a regularized polynomial regression based supervised machine learning algorithm to enhance the accuracy of the operational sensor. The algorithm uses the acquired features and corresponding labels that are the actual target distance values to train a machine learning model. The optimized training model is trained over a 1000 mm (or 1 m) experimental target distance range. Using the machine learning algorithm produces a training set and testing set distance measurement errors of learning. Applications for the proposed sensor include industrial scenario distance sensing where target material specific training models can be generated to realize low <1% measurement error distance measurements.

Optical fibre temperature sensor technology and potential application in absorbed dose calorimetry

International Nuclear Information System (INIS)

Allen, P.D.; Hargrave, N.J.

1992-09-01

Optical fibre based sensors are proposed as a potential alternative to the thermistors traditionally used as temperature sensors in absorbed dose calorimetry. The development of optical fibre temperature sensor technology over the last ten years is reviewed. The potential resolution of various optical techniques is assessed with particular reference to the requirements of absorbed dose calorimetry. Attention is drawn to other issues which would require investigation before the development of practical optical fibre sensors for this purpose could occur. 192 refs., 5 tabs., 4 figs

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.

Sensitive Leptospira DNA detection using tapered optical fiber sensor.

Science.gov (United States)

Zainuddin, Nurul H; Chee, Hui Y; Ahmad, Muhammad Z; Mahdi, Mohd A; Abu Bakar, Muhammad H; Yaacob, Mohd H

2018-03-23

This paper presents the development of tapered optical fiber sensor to detect a specific Leptospira bacteria DNA. The bacteria causes Leptospirosis, a deadly disease but with common early flu-like symptoms. Optical single mode fiber (SMF) of 125 μm diameter is tapered to produce 12 μm waist diameter and 15 cm length. The novel DNA-based optical fiber sensor is functionalized by incubating the tapered region with sodium hydroxide (NaOH), (3-Aminopropyl) triethoxysilane and glutaraldehyde. Probe DNA is immobilized onto the tapered region and subsequently hybridized by its complementary DNA (cDNA). The transmission spectra of the DNA-based optical fiber sensor are measured in the 1500 to 1600 nm wavelength range. It is discovered that the shift of the wavelength in the SMF sensor is linearly proportional with the increase in the cDNA concentrations from 0.1 to 1.0 nM. The sensitivity of the sensor toward DNA is measured to be 1.2862 nm/nM and able to detect as low as 0.1 fM. The sensor indicates high specificity when only minimal shift is detected for non-cDNA testing. The developed sensor is able to distinguish between actual DNA of Leptospira serovars (Canicola and Copenhageni) against Clostridium difficile (control sample) at very low (femtomolar) target concentrations. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization

Directory of Open Access Journals (Sweden)

Nasir Saeed

2017-12-01

Full Text Available Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB is derived for localization accuracy of the proposed technique.

Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization.

Science.gov (United States)

Saeed, Nasir; Celik, Abdulkadir; Al-Naffouri, Tareq Y; Alouini, Mohamed-Slim

2017-12-26

Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs) is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS) based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB) is derived for localization accuracy of the proposed technique.

Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization

KAUST Repository

Saeed, Nasir; Celik, Abdulkadir; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

2017-01-01

Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs) is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS) based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB) is derived for localization accuracy of the proposed technique.

Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization

KAUST Repository

Saeed, Nasir

2017-12-26

Underwater wireless technologies demand to transmit at higher data rate for ocean exploration. Currently, large coverage is achieved by acoustic sensor networks with low data rate, high cost, high latency, high power consumption, and negative impact on marine mammals. Meanwhile, optical communication for underwater networks has the advantage of the higher data rate albeit for limited communication distances. Moreover, energy consumption is another major problem for underwater sensor networks, due to limited battery power and difficulty in replacing or recharging the battery of a sensor node. The ultimate solution to this problem is to add energy harvesting capability to the acoustic-optical sensor nodes. Localization of underwater sensor networks is of utmost importance because the data collected from underwater sensor nodes is useful only if the location of the nodes is known. Therefore, a novel localization technique for energy harvesting hybrid acoustic-optical underwater wireless sensor networks (AO-UWSNs) is proposed. AO-UWSN employs optical communication for higher data rate at a short transmission distance and employs acoustic communication for low data rate and long transmission distance. A hybrid received signal strength (RSS) based localization technique is proposed to localize the nodes in AO-UWSNs. The proposed technique combines the noisy RSS based measurements from acoustic communication and optical communication and estimates the final locations of acoustic-optical sensor nodes. A weighted multiple observations paradigm is proposed for hybrid estimated distances to suppress the noisy observations and give more importance to the accurate observations. Furthermore, the closed form solution for Cramer-Rao lower bound (CRLB) is derived for localization accuracy of the proposed technique.

Multi-channel fiber optic dew and humidity sensor

Science.gov (United States)

Limodehi, Hamid E.; Mozafari, Morteza; Amiri, Hesam; Légaré, François

2018-03-01

In this article, we introduce a multi-channel fiber optic dew and humidity sensor which works using a novel method based on relation between surface plasmon resonance (SPR) and water vapor condensation. The proposed sensor can instantly detect moisture or dew formation through its fiber optic channels, separately situated in different places. It enables to simultaneously measure the ambient Relative Humidity (RH) and dew point temperature of several environments with accuracy of 5%.

Fabrication and Analysis Signal Optical Fiber Sensor Based On Bend Loss for Weight in Motion Applications

Science.gov (United States)

Aftah Syukron, Ahmad; Marzuki, Ahmad; Setyawan, Ary

2017-11-01

Road network plays very important role in economic development. Overweight is one of the main factors contributing to road damage. To minimize this factor, road authority has to make sure that all vehicles operate in according to maximum vehicle regulation set by the government. The one solution can use from this problem is Weight in motion (WIM) technology. WIM technology allows measuring vehicle weight quickly. The sensor is one of the important components in the WIM system. This paper presents a model of WIM fiber sensor work based on bend loss. Fiber sensor has made by coiling optical fiber. Coiling optical fiber has managed in the elliptical shape rubber coil. Rubber coil then is planted in the pad of sensor. The principle of this sensor is a detecting of the shift light intensity output of optical fiber when the vehicles a passing through on fiber sensor. Loading was carried out using loaded truck model. Data was carried out with variations of load and load positions in the truck. The results can be concluded that the shift light intensity is greater with the more shift loads. The loader of the truck has also resulted in the greater loss. Loads in the truck distributed on the axles due to the position of loads.

Temperature Measurement and Damage Detection in Concrete Beams Exposed to Fire Using PPP-BOTDA Based Fiber Optic Sensors.

Science.gov (United States)

Bao, Yi; Hoehler, Matthew S; Smith, Christopher M; Bundy, Matthew; Chen, Genda

2017-10-01

In this study, distributed fiber optic sensors based on pulse pre-pump Brillouin optical time domain analysis (PPP-BODTA) are characterized and deployed to measure spatially-distributed temperatures in reinforced concrete specimens exposed to fire. Four beams were tested to failure in a natural gas fueled compartment fire, each instrumented with one fused silica, single-mode optical fiber as a distributed sensor and four thermocouples. Prior to concrete cracking, the distributed temperature was validated at locations of the thermocouples by a relative difference of less than 9 %. The cracks in concrete can be identified as sharp peaks in the temperature distribution since the cracks are locally filled with hot air. Concrete cracking did not affect the sensitivity of the distributed sensor but concrete spalling broke the optical fiber loop required for PPP-BOTDA measurements.

Fibre optic sensors in pressurized water reactor alternators

International Nuclear Information System (INIS)

Favennec, J.M.; Piguet, M.

1994-01-01

Measurement in the electrical engine environment (alternator, transformer...) is identified as one of the two main applications of fibre optic sensors within EDF; the other application niche is the monitoring of civil works (dams, containment building of nuclear reactors...). At the EDF Research and Development Division, temperature and vibration fibre optic sensors were evaluated by the Metrology Service, since their use is under consideration for alternator monitoring. For alternator stator thermal monitoring, the BERTIN company developed a fibre optic sensor network. The optic coding technique is based on broadband source spectral modulation; the sensors are interrogated sequentially by electronic commutation. For alternator stator vibration monitoring, a fibre optic accelerometer was developed in the frame of a manufacturers and universities consortium supported by the French Research and Technology Ministry. The accelerometer is of cantilever beam type and its networking is possible by chromatic multiplexing. The Metrology Service evaluated these temperature and vibration sensors in order to verify their metrological characteristics (bias error, hysteresis, repeatability, resolution, noise, amplitude linearity, response time, frequency response, etc.) and to test their behaviour in harsh alternator environmental conditions (pressure, vibrations and temperature). Ageing and accidental condition resistance tests were also carried out. Temperature sensor test results were very satisfactory. An eight-sensor BERTIN prototype was installed on the Tricastin 1 alternator during the september 1993 nuclear station periodic stop. On the contrary, the accelerometers presented deficient metrological characteristics (shorter span than foreseen, low repeatability...). They need some improvements and could not be installed on alternators. (authors). 5 refs., 8 figs

Triaxial fiber optic magnetic field sensor for MRI applications

Science.gov (United States)

Filograno, Massimo L.; Pisco, Marco; Catalano, Angelo; Forte, Ernesto; Aiello, Marco; Soricelli, Andrea; Davino, Daniele; Visone, Ciro; Cutolo, Antonello; Cusano, Andrea

2016-05-01

In this paper, we report a fiber-optic triaxial magnetic field sensor, based on Fiber Bragg Gratings (FBGs) integrated with giant magnetostrictive material, the Terfenol-D. The realized sensor has been designed and engineered for Magnetic Resonance Imaging (MRI) applications. A full magneto-optical characterization of the triaxial sensing probe has been carried out, providing the complex relationship among the FBGs wavelength shift and the applied magnetostatic field vector. Finally, the developed fiber optic sensors have been arranged in a sensor network composed of 20 triaxial sensors for mapping the magnetic field distribution in a MRI-room at a diagnostic center in Naples (SDN), equipped with Positron emission tomography/magnetic resonance (PET/MR) instrumentation. Experimental results reveal that the proposed sensor network can be efficiently used in MRI centers for performing quality assurance tests, paving the way for novel integrated tools to measure the magnetic dose accumulated day by day by MRI operators.

Reagentless chemiluminescence-based fiber optic sensors for regenerative life support in space

Science.gov (United States)

Atwater, James E.; Akse, James R.; DeHart, Jeffrey; Wheeler, Richard R., Jr.

1995-04-01

The initial feasibility demonstration of a reagentless chemiluminescence based fiber optic sensor technology for use in advanced regenerative life support applications in space and planetary outposts is described. The primary constraints for extraterrestrial deployment of any technology are compatibility with microgravity and hypogravity environments; minimal size, weight, and power consumption; and minimal use of expendables due to the great expense and difficulty inherent to resupply logistics. In the current research, we report the integration of solid state flow through modules for the production of aqueous phase reagents into an integrated system for the detection of important analytes by chemiluminescence, with fiber optic light transmission. By minimizing the need for resupply expendables, the use of solid phase modules makes complex chemical detection schemes practical. For the proof of concept, hydrogen peroxide and glucose were chosen as analytes. The reaction is catalyzed by glucose oxidase, an immobilized enzyme. The aqueous phase chemistry required for sensor operation is implemented using solid phase modules which adjust the pH of the influent stream, catalyze the oxidation of analyte, and provide the controlled addition of the luminophore to the flowing aqueous stream. Precise control of the pH has proven essential for the long-term sustained release of the luminophore. Electrocatalysis is achieved using a controlled potential across gold mesh and gold foil electrodes which undergo periodic polarity reversals. The development and initial characterization of performance of the reagentless fiber optic chemiluminescence sensors are presented in this paper.

Plasmonic Optical Fiber Sensor Based on Double Step Growth of Gold Nano-Islands

Directory of Open Access Journals (Sweden)

José M. M. M. de Almeida

2018-04-01

Full Text Available It is presented the fabrication and characterization of optical fiber sensors for refractive index measurement based on localized surface plasmon resonance (LSPR with gold nano-islands obtained by single and by repeated thermal dewetting of gold thin films. Thin films of gold deposited on silica (SiO2 substrates and produced by different experimental conditions were analyzed by Scanning Electron Microscope/Dispersive X-ray Spectroscopy (SEM/EDS and optical means, allowing identifying and characterizing the formation of nano-islands. The wavelength shift sensitivity to the surrounding refractive index of sensors produced by single and by repeated dewetting is compared. While for the single step dewetting, a wavelength shift sensitivity of ~60 nm/RIU was calculated, for the repeated dewetting, a value of ~186 nm/RIU was obtained, an increase of more than three times. It is expected that through changing the fabrication parameters and using other fiber sensor geometries, higher sensitivities may be achieved, allowing, in addition, for the possibility of tuning the plasmonic frequency.

Polymer optical fiber compound parabolic concentrator tip for enhanced coupling efficiency for fluorescence based glucose sensors

DEFF Research Database (Denmark)

Hassan, Hafeez Ul; Nielsen, Kristian; Aasmul, Søren

2015-01-01

We demonstrate that the light excitation and capturing efficiency of fluorescence based fiber-optical sensors can be significantly increased by using a CPC (Compound Parabolic Concentrator) tip instead of the standard plane-cut tip. We use Zemax modelling to find the optimum CPC tip profile...... and fiber length of a polymer optical fiber diabetes sensor for continuous monitoring of glucose levels. We experimentally verify the improved performance of the CPC tipped sensor and the predicted production tolerances. Due to physical size requirements when the sensor has to be inserted into the body...... a non-optimal fiber length of 35 mm is chosen. For this length an average improvement in efficiency of a factor of 1.7 is experimentally demonstrated and critically compared to the predicted ideal factor of 3 in terms of parameters that should be improved through production optimization....

Polymer optical fiber compound parabolic concentrator tip for enhanced coupling efficiency for fluorescence based glucose sensors.

Science.gov (United States)

Hassan, Hafeez Ul; Nielsen, Kristian; Aasmul, Soren; Bang, Ole

2015-12-01

We demonstrate that the light excitation and capturing efficiency of fluorescence based fiber-optical sensors can be significantly increased by using a CPC (Compound Parabolic Concentrator) tip instead of the standard plane-cut tip. We use Zemax modelling to find the optimum CPC tip profile and fiber length of a polymer optical fiber diabetes sensor for continuous monitoring of glucose levels. We experimentally verify the improved performance of the CPC tipped sensor and the predicted production tolerances. Due to physical size requirements when the sensor has to be inserted into the body a non-optimal fiber length of 35 mm is chosen. For this length an average improvement in efficiency of a factor of 1.7 is experimentally demonstrated and critically compared to the predicted ideal factor of 3 in terms of parameters that should be improved through production optimization.

Chemical detection of liquid media with a refractrometric sensor based a multimode optical fibre

Czech Academy of Sciences Publication Activity Database

Cherif, K.; Hleli, S.; Abdelghani, A.; Jaffrezic-Renault, N.; Matějec, Vlastimil

2002-01-01

Roč. 2, č. 6 (2002), s. 195-204 ISSN 1424-8220 R&D Projects: GA ČR GA102/02/0780; GA AV ČR KSK2067107 Projekt 07/01:4074 Institutional research plan: CEZ:AV0Z2067918 Keywords : optical fibres * refractometer * optical sensors Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 0.990, year: 2002 http://www.mdpi.net/sensors

Realization of fiber optic displacement sensors

Science.gov (United States)

Guzowski, Bartlomiej; Lakomski, Mateusz

2018-03-01

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

A loss-based, magnetic field sensor implemented in a ferrofluid infiltrated microstructured polymer optical fiber

International Nuclear Information System (INIS)

Candiani, A.; Argyros, A.; Leon-Saval, S. G.; Lwin, R.; Selleri, S.; Pissadakis, S.

2014-01-01

We report an in-fiber magnetic field sensor based on magneto-driven optical loss effects, while being implemented in a ferrofluid infiltrated microstructured polymer optical fiber. We demonstrate that magnetic field flux changes up to 2000 gauss can be detected when the magnetic field is applied perpendicular to the fiber axis. In addition, the sensor exhibits high polarization sensitivity for the interrogated wavelengths, providing the possibility of both field flux and direction measurements. The underlying physical and guidance mechanisms of this sensing transduction are further investigated using spectrophotometric, light scattering measurements, and numerical simulations, suggesting photonic Hall effect as the dominant physical, transducing mechanism

Design and Development of a Magneto-Optic Sensor for Magnetic Field Measurements

Directory of Open Access Journals (Sweden)

Sarbani CHAKRABORTY

2015-01-01

Full Text Available A magneto-optic sensor is developed using a Terbium Doped Glass (TDG element as a Faraday rotation sensor and optical fiber as light transmitting and receiving medium. Online LabView based application software is developed to process the sensor output. The system is used to sense the magnetic field of a DC motor field winding in industrial environment. The sensor output is compared with the magnetic flux density variation obtained with a calibrated Hall Magnetic sensor (Gauss Meter. A linear variation of sensor output over wide range of current passing through the field winding is obtained. Further the results show an improved sensitivity of magneto-optic sensor over the Hall sensor.

Optical fiber sensors for process refractometry and temperature measuring based on curved fibers

International Nuclear Information System (INIS)

Willsch, R.; Schwotzer, G.; Haubenreisser, W.; Jahn, J.U.

1986-01-01

Based on U-shape curved multimode fibers with defined bending radii intensity-modulated optical sensors for the determination of refractive index changes in liquids and related measurands (solution concentration, mixing ratio and others) in process-refractometry and for temperature measuring under special environmental conditions have been developed. The optoelectronic transmitting and receiving units are performed in modular technique and can be used in multi-purpose applications. The principles, performance and characteristical properties of these sensors are described and their possibilities of application in process measuring and automation are discussed by some selected examples. (orig.) [de

Optical fiber sensors for process refractometry and temperature measuring based on curved fibers

Energy Technology Data Exchange (ETDEWEB)

Willsch, R; Schwotzer, G; Haubenreisser, W; Jahn, J U

1986-01-01

Based on U-shape curved multimode fibers with defined bending radii intensity-modulated optical sensors for the determination of refractive index changes in liquids and related measurands (solution concentration, mixing ratio and others) in process-refractometry and for temperature measuring under special environmental conditions have been developed. The optoelectronic transmitting and receiving units are performed in modular technique and can be used in multi-purpose applications. The principles, performance and characteristical properties of these sensors are described and their possibilities of application in process measuring and automation are discussed by some selected examples.

Design of an optically stable pH sensor based on immobilization of Giemsa on triacetylcellulose membrane.

Science.gov (United States)

Khodadoust, Saeid; Kouri, Narges Cham; Talebiyanpoor, Mohammad Sharif; Deris, Jamile; Pebdani, Arezou Amiri

2015-12-01

In this work a simple, inexpensive, and sensitive optical sensor based on triacetylcellulose membrane as solid support was developed by using immobilization of Giemsa indicator for pH measurement. In this method, the influence variables on the membrane performance including pH concentration of indicator, response time, ionic strength, and reversibility were investigated. At optimum values of all variables the response of optical pH sensor is linear in the pH range of 3.0-12.0. This optical sensor was produced through simultaneous binding of the Giemsa on the activated triacetylcellulose membrane which responded to the pH changes in a broader linear range within less than 2.0 min and suitable reproducibility (RSDsensor was stable after 6 months of storage in the water/ethanol (50:50, v/v) solution without any measurable divergence in response properties (less than 5% RSD). Copyright © 2015 Elsevier B.V. All rights reserved.

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

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...

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.

Optical Fiber Sensors Based on Polymeric Sensitive Coatings

Directory of Open Access Journals (Sweden)

Pedro J. Rivero

2018-03-01

Full Text Available Polymer technology is one of the fastest growing fields of contemporary research due to the possibility of using a wide variety of synthetic chemical routes for obtaining a polymeric network with a well-defined structure, resulting in materials with outstanding macroscopic properties. Surface engineering techniques based on the implementation of polymeric structures can be used as an interesting tool for the design of materials with functional properties. In this sense, the use of fabrication techniques for the design of nanostructured polymeric coatings is showing an important growth due to the intrinsic advantages of controlling the structure at a nanoscale level because physical, chemical, or optical properties can be considerably improved in comparison with the bulk materials. In addition, the presence of these sensitive polymeric coatings on optical fiber is a hot topic in the scientific community for its implementation in different market niches because a wide variety of parameters can be perfectly measured with a high selectivity, sensitivity, and fast response time. In this work, the two main roles that a polymeric sensitive matrix can play on an optical fiber for sensing applications are evaluated. In a first section, the polymers are used as a solid support for the immobilization of specific sensitive element, whereas in the second section the polymeric matrix is used as the chemical transducer itself. Additionally, potential applications of the optical fiber sensors in fields as diverse as biology, chemistry, engineering, environmental, industry or medicine will be presented in concordance with these two main roles of the polymeric sensitive matrices.

A Review of Microfiber-Based Temperature Sensors

Directory of Open Access Journals (Sweden)

Wanvisa Talataisong

2018-02-01

Full Text Available Optical microfiber-based temperature sensors have been proposed for many applications in a variety of industrial uses, including biomedical, geological, automotive, and defense applications. This increasing demand for these micrometric devices is attributed to their large dynamic range, high sensitivity, fast-response, compactness and robustness. Additionally, they can perform in-situ measurements remotely and in harsh environments. This paper presents an overview of optical microfibers, with a focus on their applications in temperature sensing. This review broadly divides microfiber-based temperature sensors into two categories: resonant and non-resonant microfiber sensors. While the former includes microfiber loop, knot and coil resonators, the latter comprises sensors based on functionally coated/doped microfibers, microfiber couplers, optical gratings and interferometers. In the conclusions, a summary of reported performances is presented.

Monolithic fiber optic sensor assembly

Science.gov (United States)

Sanders, Scott

2015-02-10

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

Evaluation of event-based algorithms for optical flow with ground-truth from inertial measurement sensor

Directory of Open Access Journals (Sweden)

Bodo eRückauer

2016-04-01

Full Text Available In this study we compare nine optical flow algorithms that locally measure the flow normal to edges according to accuracy and computation cost. In contrast to conventional, frame-based motion flow algorithms, our open-source implementations compute optical flow based on address-events from a neuromorphic Dynamic Vision Sensor (DVS. For this benchmarking we created a dataset of two synthesized and three real samples recorded from a 240x180 pixel Dynamic and Active-pixel Vision Sensor (DAVIS. This dataset contains events from the DVS as well as conventional frames to support testing state-of-the-art frame-based methods. We introduce a new source for the ground truth: In the special case that the perceived motion stems solely from a rotation of the vision sensor around its three camera axes, the true optical flow can be estimated using gyro data from the inertial measurement unit integrated with the DAVIS camera. This provides a ground-truth to which we can compare algorithms that measure optical flow by means of motion cues. An analysis of error sources led to the use of a refractory period, more accurate numerical derivatives and a Savitzky-Golay filter to achieve significant improvements in accuracy. Our pure Java implementations of two recently published algorithms reduce computational cost by up to 29% compared to the original implementations. Two of the algorithms introduced in this paper further speed up processing by a factor of 10 compared with the original implementations, at equal or better accuracy. On a desktop PC, they run in real-time on dense natural input recorded by a DAVIS camera.

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

Science.gov (United States)

Kersten, Ralf T. (Editor)

1990-01-01

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

Development and Performance Evaluation of Optical Sensors for High Temperature Engine Applications

Science.gov (United States)

Adamovsky, G.; Varga, D.; Floyd, B.

2011-01-01

This paper discusses fiber optic sensors designed and constructed to withstand extreme temperatures of aircraft engine. The paper describes development and performance evaluation of fiber optic Bragg grating based sensors. It also describes the design and presents test results of packaged sensors subjected to temperatures up to 1000 C for prolonged periods of time.

Development of a Brillouin scattering based distributed fibre optic strain sensor

Science.gov (United States)

Brown, Anthony Wayne

2001-07-01

The parameters of the Brillouin spectrum of an optical fibre depend upon the strain and temperature conditions of the fibre. As a result, fibre optic distributed sensors based on Brillouin scattering can measure strain and temperature in arbitrary regions of a sensing fibre. In the past, such sensors have often been demonstrated under laboratory conditions, demonstrating the principle of operation. Although some field tests of temperature sensing have been reported, the actual deployment of such sensors in the field for strain measurements has been limited by poor spatial resolution (typically 1 m or more) and poor strain accuracy (+/-100 muepsilon). Also, cross-sensitivity of the Brillouin spectrum to temperature further reduces the accuracy of strain measurement while long acquisition times hinders field use. The high level of user knowledge and lack of automation required to operate the equipment is another limiting factor of the only commercially available unit. The potential benefits of distributed measurements are great for instrumentation of civil structures provided that the above limitations are overcome. However, before this system is used with confidence by practitioners, it is essential that it can be effectively operated in field conditions. In light of this, the fibre optics group at the University of New Brunswick has been developing an automated system for field measurement of strain in civil structures, particularly in reinforced concrete. The development of the sensing system hardware and software was the main focus of this thesis. This has been made possible, in part, by observation of the Brillouin spectrum for the case of using very short light pulses (performance to measure strain to an accuracy of 10 muepsilon; and allow the simultaneous measurement of strain and temperature to an accuracy of 204 muepsilon and 3°C are presented. Finally, the results of field measurement of strain on a concrete structure are presented.

Fiber-Optic Pressure Sensor With Dynamic Demodulation Developed

Science.gov (United States)

Lekki, John D.

2002-01-01

Researchers at the NASA Glenn Research Center developed in-house a method to detect pressure fluctuations using a fiber-optic sensor and dynamic signal processing. This work was in support of the Intelligent Systems Controls and Operations project under NASA's Information Technology Base Research Program. We constructed an optical pressure sensor by attaching a fiber-optic Bragg grating to a flexible membrane and then adhering the membrane to one end of a small cylinder. The other end of the cylinder was left open and exposed to pressure variations from a pulsed air jet. These pressure variations flexed the membrane, inducing a strain in the fiber-optic grating. This strain was read out optically with a dynamic spectrometer to record changes in the wavelength of light reflected from the grating. The dynamic spectrometer was built in-house to detect very small wavelength shifts induced by the pressure fluctuations. The spectrometer is an unbalanced interferometer specifically designed for maximum sensitivity to wavelength shifts. An optimum pathlength difference, which was determined empirically, resulted in a 14-percent sensitivity improvement over theoretically predicted path-length differences. This difference is suspected to be from uncertainty about the spectral power difference of the signal reflected from the Bragg grating. The figure shows the output of the dynamic spectrometer as the sensor was exposed to a nominally 2-kPa peak-to-peak square-wave pressure fluctuation. Good tracking, sensitivity, and signal-to-noise ratios are evident even though the sensor was constructed as a proof-of-concept and was not optimized in any way. Therefore the fiber-optic Bragg grating, which is normally considered a good candidate as a strain or temperature sensor, also has been shown to be a good candidate for a dynamic pressure sensor.

High-temperature fiber optic pressure sensor

Science.gov (United States)

Berthold, J. W.

1984-01-01

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

Quality monitoring of extra-virgin olive oil using an optical sensor

Science.gov (United States)

Mignani, A. G.; Ciaccheri, L.; Mencaglia, A. A.; Paolesse, R.; Di Natale, C.; Del Nobile, A.; Benedetto, A.; Mentana, A.

2006-04-01

An optical sensor for the detection of olive oil aroma is presented. It is capable of distinguishing different ageing levels of extra-virgin olive oils, and shows effective potential for achieving a non destructive olfactory perception of oil ageing. The sensor is an optical scanner, fitted with an array of metalloporphyrin-based sensors. The scanner provides exposure of the sensors to the flow of the oil vapor being tested, and their sequential spectral interrogation. Spectral data are then processed using chemometric methodologies.

Fluoride contamination sensor based on optical fiber grating technology

Science.gov (United States)

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

2017-11-01

A number of distinct advantages of the optical fiber technology in the field of sensors and communications which leads to enormous applications. Fiber Bragg grating (FBG) developed from the fabrication of photosensitive fiber through phase mask technique is used in the present report. The designed fiber sensor used for the detection and determination of contaminants in drinking water at ppm & ppb level and it is considered as a special type of concentration sensor. The test samples of drinking water have been collected from different regions. In this paper we have calibrated the FBG sensor to detect Flouride concentration in drinking water in the range of 0.05-8 ppm. According to WHO, the normal range of fluoride content in drinking water is about 0.7 ppm to 1.5 ppm. The results for resultant spectral shifts for test samples are closely agree with standard values.

Reflection-based fibre-optic refractive index sensor using surface plasmon resonance

Czech Academy of Sciences Publication Activity Database

Hlubina, P.; Kadulová, M.; Ciprian, D.; Sobota, Jaroslav

2014-01-01

Roč. 9, August 19 (2014), 14033:1-5 ISSN 1990-2573 R&D Projects: GA MŠk(CZ) LO1212 Keywords : surface plasmon resonance * fibre-optic sensor * spectral interrogation technique * aqueous solutions of ethanol * refractive index Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.231, year: 2014

Integrated optical electric field sensor based on a Bragg grating in lithium niobate

Science.gov (United States)

Runde, D.; Brunken, S.; Rüter, C. E.; Kip, D.

2007-01-01

We demonstrate a new sensor concept for the measurement of oscillating electric fields that is based on Bragg gratings in LiNbO3:Ti channel waveguides. This miniaturized sensor that works in a retroreflective scheme does not require metallic electrodes and can be directly immersed in an oscillating electric field. The electric field induces a shift of the Bragg wavelength of the reflection grating that is due to the electro-optic effect. The operating point of the sensor is chosen by adjusting the laser wavelength to the slope of the spectral reflectivity function of the grating. In this way the magnitude of an external electric field is measured precisely as the amplitude of modulated reflected light intensity by using a lock-in amplifier. The sensor principle is demonstrated by detecting low-frequency electric fields ranging from 50 V/cm to 5 kV/cm without any conducting parts of the sensor head. Furthermore, the ability of the sensor to determine the three-dimensional orientation of an external electric field by a single rotation along the waveguide direction is demonstrated.

Localization of Energy Harvesting Empowered Underwater Optical Wireless Sensor Networks

KAUST Repository

Saeed, Nasir

2017-12-20

In this paper, a received signal strength (RSS) based localization technique is developed for energy harvesting underwater optical wireless sensor networks (EH-UOWSNs), where the optical noise sources and channel impairments of seawater pose significant challenges for range estimation. Energy limitation is another major problem due to the limited battery power and difficulty in replacing or recharging the battery of an underwater sensor node. In the proposed framework, sensor nodes with insufficient battery, harvest the energy and starts communicating once it has sufficient energy storage. Network localization is carried out by measuring the RSSs of active nodes, which are modeled based on the underwater optical communication channel characteristics. Thereafter, block kernel matrices are computed for the RSS based range measurements. Unlike the traditional shortest-path approach, the proposed technique reduces the shortest path estimation for each block kernel matrix. Once the complete block kernel matrices are available, a closed form localization technique is developed to find the location of every optical sensor node in the network. Furthermore, an analytical expression for Cramer Rao lower bound (CRLB) is derived as a benchmark to compare the localization performance of the proposed technique. Finally, extensive simulations show that the proposed technique outperforms the well-known network localization techniques.

An Improved Measurement Method for the Strength of Radiation of Reflective Beam in an Industrial Optical Sensor Based on Laser Displacement Meter

OpenAIRE

Youngchul Bae

2016-01-01

An optical sensor such as a laser range finder (LRF) or laser displacement meter (LDM) uses reflected and returned laser beam from a target. The optical sensor has been mainly used to measure the distance between a launch position and the target. However, optical sensor based LRF and LDM have numerous and various errors such as statistical errors, drift errors, cyclic errors, alignment errors and slope errors. Among these errors, an alignment error that contains measurement error for the stre...

Optical fiber powered pressure sensor

International Nuclear Information System (INIS)

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

1987-01-01

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

Optical sensors for the measurement of electric current and voltage

Energy Technology Data Exchange (ETDEWEB)

Rutgers, W R; Hulshof, H J.M.; Laurensse, I J; van der Wey, A H

1987-01-01

Optical sensors for the measurement of electrical current and voltage were developed for application in electric power systems. The current sensor, based on the Faraday effect in a monomode glass fiber, and the voltage sensor, based on the transverse Pockels effect in a crystal, are demonstrated in wide-band (10 MHz) interference-free measurements of pulsed currents and impulse voltages.

Development of an optical fiber flow velocity sensor.

Science.gov (United States)

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

2009-01-01

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

EXPERIMENTAL COMPARISON OF HOMODYNE DEMODULATION ALGORITHMS FOR PHASE FIBER-OPTIC SENSOR

Directory of Open Access Journals (Sweden)

M. N. Belikin

2015-11-01

Full Text Available Subject of Research. The paper presents the results of experimental comparative analysis of homodyne demodulation algorithms based on differential cross multiplying method and on arctangent method under the same conditions. The dependencies of parameters for the output signals on the optical radiation intensity are studied for the considered demodulation algorithms. Method. The prototype of single fiber optic phase interferometric sensor has been used for experimental comparison of signal demodulation algorithms. Main Results. We have found that homodyne demodulation based on arctangent method provides greater (by 7 dB at average signal-to-noise ratio of output signals over the frequency band of acoustic impact from 100 Hz to 500 Hz as compared to differential cross multiplying algorithms. We have demonstrated that no change in the output signal amplitude occurs for the studied range of values of the optical pulses amplitudes. Obtained results indicate that the homodyne demodulation based on arctangent method is most suitable for application in the phase fiber-optic sensors. It provides higher repeatability of their characteristics than the differential cross multiplying algorithm. Practical Significance. Algorithms of interferometric signals demodulation are widely used in phase fiber-optic sensors. Improvement of their characteristics has a positive effect on the performance of such sensors.

Interferometric interrogation concepts for integrated electro-optical sensor systems

NARCIS (Netherlands)

Ikkink, T.J.; Ikkink, Teunis Jan

1998-01-01

Integrated optical sensors have a high potential in the measurement of a large variety of measurands. Research on integrated optical sensors enjoys increasing interest. In order to reach accurate performance and to facilitate the use of integrated optical sensors, electronic functions for sensor

Guided wave and damage detection in composite laminates using different fiber optic sensors.

Science.gov (United States)

Li, Fucai; Murayama, Hideaki; Kageyama, Kazuro; Shirai, Takehiro

2009-01-01

Guided wave detection using different fiber optic sensors and their applications in damage detection for composite laminates were systematically investigated and compared in this paper. Two types of fiber optic sensors, namely fiber Bragg gratings (FBG) and Doppler effect-based fiber optic (FOD) sensors, were addressed and guided wave detection systems were constructed for both types. Guided waves generated by a piezoelectric transducer were propagated through a quasi-isotropic carbon fiber reinforced plastic (CFRP) laminate and acquired by these fiber optic sensors. Characteristics of these fiber optic sensors in ultrasonic guided wave detection were systematically compared. Results demonstrated that both the FBG and FOD sensors can be applied in guided wave and damage detection for the CFRP laminates. The signal-to-noise ratio (SNR) of guided wave signal captured by an FOD sensor is relatively high in comparison with that of the FBG sensor because of their different physical principles in ultrasonic detection. Further, the FOD sensor is sensitive to the damage-induced fundamental shear horizontal (SH(0)) guided wave that, however, cannot be detected by using the FBG sensor, because the FOD sensor is omnidirectional in ultrasound detection and, in contrast, the FBG sensor is severely direction dependent.

A Transflective Nano-Wire Grid Polarizer Based Fiber-Optic Sensor

Directory of Open Access Journals (Sweden)

Yan-Qing Lu

2011-02-01

Full Text Available A transflective nano-wire grid polarizer is fabricated on a single mode fiber tip by focused ion beam machining. In contrast to conventional absorptive in-line polarizers, the wire grids reflect TE-mode, while transmitting TM-mode light so that no light power is discarded. A reflection contrast of 13.7 dB and a transmission contrast of 4.9 dB are achieved in the 1,550 nm telecom band using a 200-nm wire grid fiber polarizer. With the help of an optic circulator, the polarization states of both the transmissive and reflective lights in the fiber may be monitored simultaneously. A kind of robust fiber optic sensor is thus proposed that could withstand light power variations. To verify the idea, a fiber pressure sensor with the sensitivity of 0.24 rad/N is demonstrated. The corresponding stress-optic coefficient of the fiber is measured. In addition to pressure sensing, this technology could be applied in detecting any polarization state change induced by magnetic fields, electric currents and so on.

Fiber optic refractive index and magnetic field sensors based on microhole-induced inline Mach-Zehnder interferometers

Science.gov (United States)

Chen, Feifei; Jiang, Yi; Zhang, Liuchao; Jiang, Lan; Wang, Sumei

2018-04-01

A compact microhole-induced fiber optic inline Mach-Zehnder interferometer (MZI) is demonstrated for measurements of refractive index (RI) and magnetic field. Inline MZIs with different etched diameters, different interaction lengths and different sizes of microholes are fabricated and assessed. The optical transmission spectra of the inline MZIs immersed into a series of liquids are characterized and analysed. Experimental results show that liquid RI sensitivity as high as 539.8436 nm RIU-1 in the RI range of 1.3352-1.4113 RIU is achieved and also exhibits good linearity with a correlation coefficient  >93%. An inline MZI is also fabricated to be a magnetic field sensor by using magnetic fluid material. The experimental results show that this magnetic field sensor has a high sensitivity of  -275.6 pm Oe-1. The inline MZI-based fiber optic sensors possess many advantages, such as small size, simple fabrication, high sensitivity and good linearity, which has a wide application potential in chemical, biological and environmental sensing fields.

Experimental results for characterization of a tapered plastic optical fiber sensor based on SPR

Science.gov (United States)

Cennamo, N.; Galatus, R.; Zeni, L.

2015-05-01

The experimental results obtained with two different Plastic Optical Fiber (POF) geometries, tapered and not-tapered, for a sensor based on Surface Plasmon Resonance (SPR) are presented. SPR is used for determining the refractive index variations at the interface between a gold layer and a dielectric medium (aqueous medium). In this work SPR sensors in POF configurations, useful for bio-sensing applications, have been realized for the optimization of the sensitivity and experimentally tested. The results show as the sensitivity increases with the tapered POF configuration, when the refractive index of aqueous medium increases.

Ultrahigh-sensitive multimode interference-based fiber optic liquid-level sensor realized using illuminating zero-order Bessel-Gauss beam

Science.gov (United States)

Saha, Ardhendu; Datta, Arijit; Kaman, Surjit

2018-03-01

A proposal toward the enhancement in the sensitivity of a multimode interference-based fiber optic liquid-level sensor is explored analytically using a zero-order Bessel-Gauss (BG) beam as the input source. The sensor head consists of a suitable length of no-core fiber (NCF) sandwiched between two specialty high-order mode fibers. The coupling efficiency of various order modes inside the sensor structure is assessed using guided-mode propagation analysis and the performance of the proposed sensor has been benchmarked against the conventional sensor using a Gaussian beam. Furthermore, the study has been corroborated using a finite-difference beam propagation method in Lumerical's Mode Solutions software to investigate the propagation of the zero-order BG beam inside the sensor structure. Based on the simulation outcomes, the proposed scheme yields a maximum absolute sensitivity of up to 3.551 dB / mm and a sensing resolution of 2.816 × 10 - 3 mm through the choice of an appropriate length of NCF at an operating wavelength of 1.55 μm. Owing to this superior sensing performance, the reported sensing technology expedites an avenue to devise a high-performance fiber optic-level sensor that finds profound implication in different physical, biological, and chemical sensing purposes.

Coordinating standards and applications for optical water quality sensor networks

Science.gov (United States)

Bergamaschi, B.; Pellerin, B.

2011-01-01

Joint USGS-CUAHSI Workshop: In Situ Optical Water Quality Sensor Networks; Shepherdstown, West Virginia, 8-10 June 2011; Advanced in situ optical water quality sensors and new techniques for data analysis hold enormous promise for advancing scientific understanding of aquatic systems through measurements of important biogeochemical parameters at the time scales over which they vary. High-frequency and real-time water quality data also provide the opportunity for early warning of water quality deterioration, trend detection, and science-based decision support. However, developing networks of optical sensors in freshwater systems that report reliable and comparable data across and between sites remains a challenge to the research and monitoring community. To address this, the U.S. Geological Survey (USGS) and the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI), convened a 3-day workshop to explore ways to coordinate development of standards and applications for optical sensors, as well as handling, storage, and analysis of the continuous data they produce.

A Flexible Optical pH Sensor Based on Polysulfone Membranes Coated with pH-Responsive Polyaniline Nanofibers.

Science.gov (United States)

Abu-Thabit, Nedal; Umar, Yunusa; Ratemi, Elaref; Ahmad, Ayman; Ahmad Abuilaiwi, Faraj

2016-06-27

A new optical pH sensor based on polysulfone (PSU) and polyaniline (PANI) was developed. A transparent and flexible PSU membrane was employed as a support. The electrically conductive and pH-responsive PANI was deposited onto the membrane surface by in situ chemical oxidative polymerization (COP). The absorption spectra of the PANI-coated PSU membranes exhibited sensitivity to pH changes in the range of 4-12, which allowed for designing a dual wavelength pH optical sensor. The performance of the membranes was assessed by measuring their response starting from high pH and going down to low pH, and vice versa. It was found that it is necessary to precondition the sensor layers before each measurement due to the slight hysteresis observed during forward and backward pH titrations. PSU membranes with polyaniline coating thicknesses in the range of ≈100-200 nm exhibited fast response times of pH sensor was characterized by a sigmoidal response (R² = 0.997) which allows for pH determination over a wide dynamic range. All membranes were stable for a period of more than six months when stored in 1 M HCl solution. The reproducibility of the fabricated optical pH sensors was found to be pH sensor was tested and the obtained pH values were compared with the results obtained using a pH meter device.

Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

OpenAIRE

Md. Rajibur Rahaman Khan; Shin-Won Kang

2016-01-01

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal?s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The...

Compact magnetic-field sensor based on optical microfiber Michelson interferometer and Fe3O4 nanofluid.

Science.gov (United States)

Deng, Ming; Sun, Xiaokang; Han, Meng; Li, Decai

2013-02-01

We report a magnetic-field sensor by merging the advantages of optical fiber Michelson interferometers with that of magnetic fluid. Compact and low-cost optical fiber Michelson interferometers were first fabricated by a high-frequency CO(2) laser, and then they were inserted into glass capillaries with water-based Fe(3)O(4) magnetic fluid as sensing elements. The sensing characteristics have been investigated and the experimental results show that the reflective spectrum of the fiber-magnetic sensor linearly shifted with the change of the magnetic-field strength that is perpendicular to the axial of the devices. The fiber-magnetic sensor with interference arm's diameter of 50 μm is most sensitive to the external magnetic field, and the sensitivity is up to 64.9 pm/mT, which is 20 times higher than that of 125 μm diameter.

A fiber optic temperature sensor based on multi-core microstructured fiber with coupled cores for a high temperature environment

Science.gov (United States)

Makowska, A.; Markiewicz, K.; Szostkiewicz, L.; Kolakowska, A.; Fidelus, J.; Stanczyk, T.; Wysokinski, K.; Budnicki, D.; Ostrowski, L.; Szymanski, M.; Makara, M.; Poturaj, K.; Tenderenda, T.; Mergo, P.; Nasilowski, T.

2018-02-01

Sensors based on fiber optics are irreplaceable wherever immunity to strong electro-magnetic fields or safe operation in explosive atmospheres is needed. Furthermore, it is often essential to be able to monitor high temperatures of over 500°C in such environments (e.g. in cooling systems or equipment monitoring in power plants). In order to meet this demand, we have designed and manufactured a fiber optic sensor with which temperatures up to 900°C can be measured. The sensor utilizes multi-core fibers which are recognized as the dedicated medium for telecommunication or shape sensing, but as we show may be also deployed advantageously in new types of fiber optic temperature sensors. The sensor presented in this paper is based on a dual-core microstructured fiber Michelson interferometer. The fiber is characterized by strongly coupled cores, hence it acts as an all-fiber coupler, but with an outer diameter significantly wider than a standard fused biconical taper coupler, which significantly increases the coupling region's mechanical reliability. Owing to the proposed interferometer imbalance, effective operation and high-sensitivity can be achieved. The presented sensor is designed to be used at high temperatures as a result of the developed low temperature chemical process of metal (copper or gold) coating. The hermetic metal coating can be applied directly to the silica cladding of the fiber or the fiber component. This operation significantly reduces the degradation of sensors due to hydrolysis in uncontrolled atmospheres and high temperatures.

Experimental Investigation of Integrated Optical Intensive Impulse Electric Field Sensors

International Nuclear Information System (INIS)

Bao, Sun; Fu-Shen, Chen

2009-01-01

We design and fabricate an integrated optical electric field sensor with segmented electrode for intensive impulse 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 maximal 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

A Robust Distributed Multipoint Fiber Optic Gas Sensor System Based on AGC Amplifier Structure.

Science.gov (United States)

Zhu, Cunguang; Wang, Rende; Tao, Xuechen; Wang, Guangwei; Wang, Pengpeng

2016-07-28

A harsh environment-oriented distributed multipoint fiber optic gas sensor system realized by automatic gain control (AGC) technology is proposed. To improve the photoelectric signal reliability, the electronic variable gain can be modified in real time by an AGC closed-loop feedback structure to compensate for optical transmission loss which is caused by the fiber bend loss or other reasons. The deviation of the system based on AGC structure is below 4.02% when photoelectric signal decays due to fiber bending loss for bending radius of 5 mm, which is 20 times lower than the ordinary differential system. In addition, the AGC circuit with the same electric parameters can keep the baseline intensity of signals in different channels of the distributed multipoint sensor system at the same level. This avoids repetitive calibrations and streamlines the installation process.

Blood detection in the spinal column of whole cooked chicken using an optical fibre based sensor system

Science.gov (United States)

Sheridan, C.; O'Farrell, M.; Lyons, W. B.; Lewis, E.; Flanagan, C.; Jackman, N.

2005-01-01

An optical fibre based sensor has been developed to aid the quality assurance of food cooked in industrial ovens by monitoring the product in situ as it cooks. The sensor measures the product colour as it cooks by examining the reflected visible light from the surface as well as the core of the product. This paper examines the use of the sensor for the detection of blood in the spinal area of cooked whole chickens. The results presented here show that the sensor can be successfully used for this purpose.

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.

Electro-optical rendezvous and docking sensors

Science.gov (United States)

Tubbs, David J.; Kesler, Lynn O.; Sirko, Robert J.

1991-01-01

Electro-optical sensors provide unique and critical functionality for space missions requiring rendezvous, docking, and berthing. McDonnell Douglas is developing a complete rendezvous and docking system for both manned and unmanned missions. This paper examines our sensor development and the systems and missions which benefit from rendezvous and docking sensors. Simulation results quantifying system performance improvements in key areas are given, with associated sensor performance requirements. A brief review of NASA-funded development activities and the current performance of electro-optical sensors for space applications is given. We will also describe current activities at McDonnell Douglas for a fully functional demonstration to address specific NASA mission needs.

Temperature monitoring and leak detection in sodium circuits of FBR using Raman distributed fiber optic sensor

International Nuclear Information System (INIS)

Kasinathan, M.; Murali, N.; Sosamma, S.; Babu Rao, C.; Kumar, Anish; Purnachandra Rao, B.; Jayakumar, T.

2013-01-01

This paper discusses the fiber optic temperature sensor based leak detection in the coolant circuits of fast breeder reactor. These sensors measure the temperature based on spontaneous Raman scattering principle and is not influenced by the electromagnetic interference. Various experiments were conducted to evaluate the performance of the fiber optic sensor based leak detection using Raman distributed Temperature Sensor (RDTS). This paper also deals with the details of fiber optic sensor type leak detector layout for the coolant circuit of FBR, performance requirement of leak detection system, description of the test facility, experimental procedure and test results of various experiments conducted. (author)

Miniaturised optical sensors for industrial applications

DEFF Research Database (Denmark)

Jakobsen, Michael Linde; Hanson, Steen Grüner

2010-01-01

. 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...... of the two optical solutions is less than 1 cm3, including the application specific integrated circuit (ASIC), which processes the data and interfaces a PC/Laptop directly via a USB driver. The sensors are designed for working distances of 2 and 12 mm for near field and far field, respectively. We...

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

This report summarizes technical progress on the program “Single-Crystal Sapphire Optical Fiber Sensor Instrumentation,” funded by the National Energy Technology Laboratory 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. This project was completed in three phases, each with a separate focus. Phase I of the program, from October 1999 to April 2002, was devoted to development of sensing schema for use in high temperature, harsh environments. Different sensing designs were proposed and tested in the laboratory. Phase II of the program, from April 2002 to April 2009, focused on bringing the sensor technologies, which had already been successfully demonstrated in the laboratory, to a level where the sensors could be deployed in harsh industrial environments and eventually become commercially viable through a series of field tests. Also, a new sensing scheme was developed and tested with numerous advantages over all previous ones in Phase II. Phase III of the program, September 2009 to December 2013, focused on development of the new sensing scheme for field testing in conjunction with materials engineering of the improved sensor packaging lifetimes. In Phase I, three different sensing principles were studied: sapphire air-gap extrinsic Fabry-Perot sensors; intensity-based polarimetric sensors; and broadband polarimetric sensors. Black body radiation tests and corrosion tests were also performed in this phase. The outcome of the first phase of this program was the selection of broadband polarimetric differential interferometry (BPDI) for further prototype instrumentation development. This approach is based on the measurement of the optical path difference (OPD) between two orthogonally polarized light beams in a single-crystal sapphire disk. At the beginning of Phase II, in June 2004, the BPDI sensor was tested at the Wabash River coal gasifier

Monitoring of pipeline deformations using optical fiber sensors based on Bragg lattices; Monitoracao de deformacoes em dutos utilizando sensores a fibra optica com base em redes de Bragg

Energy Technology Data Exchange (ETDEWEB)

Moszkowica, Viktor Nigri [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)]. E-mail: vnigri@bol.com.br

2002-06-01

In the petroleum sector there is a growing need for the use of pipelines as well as for their monitoring. A way to avoid leaks that can cause great damage to the environment is by the monitoring of deformations. In case failures can not be avoided through operational procedures, the monitoring of deformations can identify the initial moment and location of the leak, allowing for quick action on the part of the cleaning and depollution teams. Also important is the monitoring of slopes and soil movements. The same thing applies to production and transfer submarine pipelines subject to complex dynamic loadings that combine internal and external pressure, torsion, axial stress and, the most common of all, flexion loading. For this type of application, optical fiber sensors present a number of interesting features. Multiplexing, remote operation and long distance distribution of sensors are characteristics that attract their use in deformation monitoring systems. Presented herein are the research results of works that had the objective of developing deformation monitoring techniques in pipelines using optical fiber sensors based on Bragg grating. The technical feasibility of this technology is demonstrated through laboratorial tests. Also discussed herein are methods for field implementation of sensors, optical signal multiplexing techniques and potential advantages of applying this technology. (author)

Fiber optic temperature sensors for medical applications

Science.gov (United States)

Schaafsma, David T.; Palmer, Gail; Bechtel, James H.

2003-07-01

Recent developments in fiber-optic sensor technology have demonstrated the utility of fiber-optic sensors for both medical and industrial applications. Fiber sensors based on fluorescent decay of rare earth doped materials allow rapid and accurate temperature measurement in challenging environments. Here we review the principles of operation of these sensors with a rare earth doped probe material and demonstrate why this material is an excellent choice for these types of sensors. The decay time technique allows accurate temperature determination from two measurements of the fluorescence intensity at a well-defined time interval. With this method, all instrumental and extraneous environmental effect will cancel, thus providing an accurate temperature measurement. Stability data will be presented for the fiber-optic probes. For medical applications, new breakthroughs in RF ablation technology and electro-surgical procedures are being introduced as alternative, less invasive treatment for removal of small tumors and for removal of plaque within arteries as a preventive treatment that avoids open heart surgery. The availability of small diameter temperature probes (230 microns or 450 microns in diameter) offers a whole new scope to temperature measurement. Accurate and reliable temperature monitoring during any laser treatment procedure or RF ablation at the surgical site is critical. Precise, NIST traceable reliable results are needed to prevent overheating or underheating during treatment. In addition, how interventional catheters are used in hyperthermia studies and the advantages to having flexible cables and multiple sensors are discussed. Preliminary data is given from an animal study where temperature was monitored in a pig during an RF study.

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

Science.gov (United States)

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

2013-03-01

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

Process monitoring of fibre reinforced composites using optical fibre sensors

Energy Technology Data Exchange (ETDEWEB)

Fernando, G.F.; Degamber, B.

2006-04-15

The deployment of optical fibre based sensor systems for process monitoring of advanced fibre reinforced organic matrix composites is reviewed. The focus is on thermosetting resins and the various optical and spectroscopy-based techniques that can be used to monitor the processing of these materials. Following brief consideration of the manufacturing methods commonly used in the production of thermoset based composites, a discussion is presented on sensor systems that can be used to facilitate real-time chemical process monitoring. Although the focus is on thermosets, the techniques described can be adapted for chemical monitoring of organic species in general. (author)

Ionic Liquid-Based Optical and Electrochemical Carbon Dioxide Sensors

Science.gov (United States)

Behera, Kamalakanta; Pandey, Shubha; Kadyan, Anu; Pandey, Siddharth

2015-01-01

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. PMID:26690155

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.

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.

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

International Nuclear Information System (INIS)

Akhiruddin maddu; Ahmad aminuddin; Setyanto Tri Wahyudi; Hamdani Zain

2008-01-01

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

A Flexible Optical pH Sensor Based on Polysulfone Membranes Coated with pH-Responsive Polyaniline Nanofibers

Directory of Open Access Journals (Sweden)

Nedal Abu-Thabit

2016-06-01

Full Text Available A new optical pH sensor based on polysulfone (PSU and polyaniline (PANI was developed. A transparent and flexible PSU membrane was employed as a support. The electrically conductive and pH-responsive PANI was deposited onto the membrane surface by in situ chemical oxidative polymerization (COP. The absorption spectra of the PANI-coated PSU membranes exhibited sensitivity to pH changes in the range of 4–12, which allowed for designing a dual wavelength pH optical sensor. The performance of the membranes was assessed by measuring their response starting from high pH and going down to low pH, and vice versa. It was found that it is necessary to precondition the sensor layers before each measurement due to the slight hysteresis observed during forward and backward pH titrations. PSU membranes with polyaniline coating thicknesses in the range of ≈100–200 nm exhibited fast response times of <4 s, which are attributed to the porous, rough and nanofibrillar morphology of the polyaniline coating. The fabricated pH sensor was characterized by a sigmoidal response (R2 = 0.997 which allows for pH determination over a wide dynamic range. All membranes were stable for a period of more than six months when stored in 1 M HCl solution. The reproducibility of the fabricated optical pH sensors was found to be <0.02 absorption units after one month storage in 1 M HCl solution. The performance of the optical pH sensor was tested and the obtained pH values were compared with the results obtained using a pH meter device.

Micro-Optical Distributed Sensors for Aero Propulsion Applications

Science.gov (United States)

Arnold, S.; Otugen, V.

2003-01-01

The objective of this research is to develop micro-opto-mechanical system (MOMS)-based sensors for time- and space-resolved measurements of flow properties in aerodynamics applications. The measurement technique we propose uses optical resonances in dielectric micro-spheres that can be excited by radiation tunneling from optical fibers. It exploits the tunneling-induced and morphology-dependent shifts in the resonant frequencies. The shift in the resonant frequency is dependent on the size, shape, and index of refraction of the micro-sphere. A physical change in the environment surrounding a micro-bead can change one or more of these properties of the sphere thereby causing a shift in frequency of resonance. The change of the resonance frequency can be detected with high resolution by scanning a frequency-tunable laser that is coupled into the fiber and observing the transmission spectrum at the output of the fiber. It is expected that, in the future, the measurement concept will lead to a system of distributed micro-sensors providing spatial data resolved in time and space. The present project focuses on the development and demonstration of temperature sensors using the morphology-dependent optical resonances although in the latter part of the work, we will also develop a pressure sensor. During the period covered in this report, the optical and electronic equipment necessary for the experimental work was assembled and the experimental setup was designed for the single sensor temperature measurements. Software was developed for real-time tracking of the optical resonance shifts. Some preliminary experiments were also carried out to detect temperature using a single bead in a water bath.

Optical detection system for MEMS-type pressure sensor

International Nuclear Information System (INIS)

Sareło, K; Górecka-Drzazga, A; Dziuban, J A

2015-01-01

In this paper a special optical detection system designed for a MEMS-type (micro-electro-mechanical system) silicon pressure sensor is presented. The main part of the optical system—a detection unit with a perforated membrane—is bonded to the silicon sensor, and placed in a measuring system. An external light source illuminates the membrane of the pressure sensor. Owing to the light reflected from the deflected membrane sensor, the optical pattern consisting of light points is visible, and pressure can be estimated. The optical detection unit (20   ×   20   ×   20.4 mm 3 ) is fabricated using microengineering techniques. Its dimensions are adjusted to the dimensions of the pressure sensor (5   ×   5 mm 2 silicon membrane). Preliminary tests of the optical detection unit integrated with the silicon pressure sensor are carried out. For the membrane sensor from 15 to 60 µm thick, a repeatable detection of the differential pressure in the range of 0 to 280 kPa is achieved. The presented optical microsystem is especially suitable for the pressure measurements in a high radiation environment. (paper)

Priority design parameters of industrialized optical fiber sensors in civil engineering

Science.gov (United States)

Wang, Huaping; Jiang, Lizhong; Xiang, Ping

2018-03-01

Considering the mechanical effects and the different paths for transferring deformation, optical fiber sensors commonly used in civil engineering have been systematically classified. Based on the strain transfer theory, the relationship between the strain transfer coefficient and allowable testing error is established. The proposed relationship is regarded as the optimal control equation to obtain the optimal value of sensors that satisfy the requirement of measurement precision. Furthermore, specific optimization design methods and priority design parameters of the classified sensors are presented. This research indicates that (1) strain transfer theory-based optimization design method is much suitable for the sensor that depends on the interfacial shear stress to transfer the deformation; (2) the priority design parameters are bonded (sensing) length, interfacial bonded strength, elastic modulus and radius of protective layer and thickness of adhesive layer; (3) the optimization design of sensors with two anchor pieces at two ends is independent of strain transfer theory as the strain transfer coefficient can be conveniently calibrated by test, and this kind of sensors has no obvious priority design parameters. Improved calibration test is put forward to enhance the accuracy of the calibration coefficient of end-expanding sensors. By considering the practical state of sensors and the testing accuracy, comprehensive and systematic analyses on optical fiber sensors are provided from the perspective of mechanical actions, which could scientifically instruct the application design and calibration test of industrialized optical fiber sensors.

Measuring heart rate with optical sensor

NARCIS (Netherlands)

Barachi, M. (Mitra)

2014-01-01

The problem addressed in this report is to verify the possibility of using an optical sensor in the SaxShirt in order to extract the heart rate. There are specifically three questions that we try to address. 1) How is it possible to extract heart rate (BPM) from the optical sensor? 2) Is it

Applications of fiber optic sensors in concrete structural health monitoring

Science.gov (United States)

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

2007-11-01

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

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.

Fiber-optic evanescent-field sensor for attitude measurement

Science.gov (United States)

Liu, Yun; Chen, Shimeng; Liu, Zigeng; Guang, Jianye; Peng, Wei

2017-11-01

We proposed a new approach to attitude measurement by an evanescent field-based optical fiber sensing device and demonstrated a liquid pendulum. The device consisted of three fiber-optic evanescent-filed sensors which were fabricated by tapered single mode fibers and immersed in liquid. Three fiber Bragg gratings were used to measure the changes in evanescent field. And their reflection peaks were monitored in real time as measurement signals. Because every set of reflection responses corresponded to a unique attitude, the attitude of the device could be measured by the three fiber-optic evanescent-filed sensors. After theoretical analysis, computerized simulation and experimental verification, regular responses were obtained using this device for attitude measurement. The measurement ranges of dihedral angle and direction angle were 0°-50° and 0°-360°. The device is based on cost-effective power-referenced scheme. It can be used in electromagnetic or nuclear radiation environment.

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

Science.gov (United States)

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

2012-06-01

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

Bio-inspired multi-mode optic flow sensors for micro air vehicles

Science.gov (United States)

Park, Seokjun; Choi, Jaehyuk; Cho, Jihyun; Yoon, Euisik

2013-06-01

Monitoring wide-field surrounding information is essential for vision-based autonomous navigation in micro-air-vehicles (MAV). Our image-cube (iCube) module, which consists of multiple sensors that are facing different angles in 3-D space, can be applied to the wide-field of view optic flows estimation (μ-Compound eyes) and to attitude control (μ- Ocelli) in the Micro Autonomous Systems and Technology (MAST) platforms. In this paper, we report an analog/digital (A/D) mixed-mode optic-flow sensor, which generates both optic flows and normal images in different modes for μ- Compound eyes and μ-Ocelli applications. The sensor employs a time-stamp based optic flow algorithm which is modified from the conventional EMD (Elementary Motion Detector) algorithm to give an optimum partitioning of hardware blocks in analog and digital domains as well as adequate allocation of pixel-level, column-parallel, and chip-level signal processing. Temporal filtering, which may require huge hardware resources if implemented in digital domain, is remained in a pixel-level analog processing unit. The rest of the blocks, including feature detection and timestamp latching, are implemented using digital circuits in a column-parallel processing unit. Finally, time-stamp information is decoded into velocity from look-up tables, multiplications, and simple subtraction circuits in a chip-level processing unit, thus significantly reducing core digital processing power consumption. In the normal image mode, the sensor generates 8-b digital images using single slope ADCs in the column unit. In the optic flow mode, the sensor estimates 8-b 1-D optic flows from the integrated mixed-mode algorithm core and 2-D optic flows with an external timestamp processing, respectively.

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.

Optical fiber chemiluminescence sensor for iron (II) ion based on immobilized luminol

International Nuclear Information System (INIS)

Alipao, Arthur A.; Sevilla, Fortunato III.

1999-01-01

A chemiluminescence (CL) sensor for iron (II) was developed based on the catalytic action of the analyte on the CL reaction between luminol and oxygen. The reagents were immobilized on a cellulose membrane and set on a reaction cell which was coupled by means of an optical fiber to a spectrofluorometer. The concentration of iron(II) was quantified by measuring the intensity of the light generated from the CL reaction. The response of the sensor system was rapid and highly reproducible. Good sensitivity was displayed by the sensor system over the five orders of magnitude of iron(II) ion concentration. The calibration curve consisted of two portions: (1) a linear range at lower concentrations (7.5 x 10 -7 M to 1.0 x 10 -4 M) exhibiting a positive slope arising from a catalytic action, and (2) a linear range at higher concentrations (5.0 x 10 -2 M to 2.5 x 10 -4 M) wherein the slope is negative due to an inhibitory action of iron(II) on the CL reaction. The sensor system was highly selective for iron(II) ions. (Author)

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.

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

Optical thermal sensor based on cholesteric film refilled with mixture of toluene and ethanol.

Science.gov (United States)

Li, Yong; Liu, Yanjun; Luo, Dan

2017-10-16

We demonstrate an optical thermal sensor based on cholesteric film refilled with mixture of toluene and ethanol. The thermal response mechanism is mainly based on the thermal expansion effect induce by toluene, where the ethanol is used for refractive index adjustment to determine the initial refection band position of cholesteric film. The ethanol-toluene mixture was used to adjust the color tunability with the temperature in relation with the habits of people (blue as cold, green as safe and red as hot). A broad temperature range of 86 °C and highly sensitivity of 1.79 nm/ °C are achieved in proposed thermal sensor, where the reflective color red-shifts from blue to red when environmental temperature increases from -6 °C to 80 °C. This battery-free thermal sensor possesses features including simple fabrication, low-cost, and broad temperature sensing range, showing potential application in scientific research and industry.

Sensitivity Study for Sensor Optical and Electric Crosstalk Based on Spectral Measurements: An Application to Developmental Sensors Using Heritage Sensors Such As MODIS

Science.gov (United States)

Butler, James J.; Oudrari, Hassan; Xiong, Sanxiong; Che, Nianzeng; Xiong, Xiaoxiong

2007-01-01

The process of developing new sensors for space flight frequently builds upon the designs and experience of existing heritage space flight sensors. Frequently in the development and testing of new sensors, problems are encountered that pose the risk of serious impact on successful retrieval of geophysical products. This paper describes an approach to assess the importance of optical and electronic cross-talk on retrieval of geophysical products using new MODIS-like sensors through the use of MODIS data sets. These approaches may be extended to any sensor characteristic and any sensor where that characteristic may impact the Level 1 products so long as validated geophysical products are being developed from the heritage sensor. In this study, a set of electronic and/or optical cross-talk coefficients are postulated. These coefficients are sender-receiver influence coefficients and represent a sensor signal contamination on any detector on a focal plane when another band's detectors on that focal plane are stimulated with a monochromatic light. The approach involves using the postulated cross-talk coefficients on an actual set of MODIS data granules. The original MODIS data granules and the cross-talk impacted granules are used with validated geophysical algorithms to create the derived products. Comparison of the products produced with the original and cross-talk impacted granules indicates potential problems, if any, with the characteristics of the developmental sensor that are being studied.

Optical Three-Axis Tactile Sensor for Robotic Fingers

OpenAIRE

Ohka, Masahiro; Takata, Jumpei; Kobayashi, Hiroaki; Suzuki, Hirofumi; Morisawa, Nobuyuki; Yussof, Hanafiah Bin

2008-01-01

A new three-axis tactile sensor to be mounted on multi-fingered hands is developed based on the principle of an optical waveguide-type tactile sensor comprised of an acrylic hemispherical dome, a light source, an array of rubber sensing elements, and a CCD camera. The sensing element of the present tactile sensor includes one columnar feeler and eight conical feelers. A three-axis force applied to the tip of the sensing element is detected by the contact areas of the conical feelers, which ma...

Optical Fiber Grating Hydrogen Sensors: A Review.

Science.gov (United States)

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

2017-03-12

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

POF based glucose sensor incorporating grating wavelength filters

DEFF Research Database (Denmark)

Hassan, Hafeez Ul; Aasmul, Søren; Bang, Ole

2014-01-01

AND RESEARCH IN POLYMER OPTICAL DEVICES; TRIPOD. Within the domain of TRIPOD, research is conducted on "Plastic Optical Fiber based Glucose Sensors Incorporating Grating Wavelength Filters". Research will be focused to optimized fiber tips for better coupling efficiency, reducing the response time of sensor...

Highly selective single-use fluoride ion optical sensor based on aluminum(III)-salen complex in thin polymeric film

International Nuclear Information System (INIS)

Badr, Ibrahim H.A.; Meyerhoff, Mark E.

2005-01-01

A highly selective optical sensor for fluoride ion based on the use of an aluminum(III)-salen complex as an ionophore within a thin polymeric film is described. The sensor is prepared by embedding the aluminum(III)-salen ionophore and a suitable lipophilic pH-sensitive indicator (ETH-7075) in a plasticized poly(vinyl chloride) (PVC) film. Optical response to fluoride occurs due to fluoride extraction into the polymer via formation of a strong complex with the aluminum(III)-salen species. Co-extraction of protons occurs simultaneously, with protonation of the indicator dye yielding the optical response at 529 nm. Films prepared using dioctylsebacate (DOS) are shown to exhibit better response (e.g., linear range, detection limit, and optical signal stability) compared to those prepared using ortho-nitrophenyloctyl ether (o-NPOE). Films formulated with aluminum(III)-salen and ETH-7075 indicator in 2 DOS:1 PVC, exhibit a significantly enhanced selectivity for fluoride over a wide range of lipophilic anions including salicylate, perchlorate, nitrate, and thiocyanate. The optimized films exhibit a sub-micromolar detection limit, using glycine-phosphate buffer, pH 3.00, as the test sample. The response times of the fluoride optical sensing films are in the range of 1-10 min depending on the fluoride ion concentration in the sample. The sensor exhibits very poor reversibility owing to a high co-extraction constant (log K = 8.5 ± 0.4), indicating that it can best be employed as a single-use transduction device. The utility of the aluminum(III)-salen based fluoride sensitive films as single-use sensors is demonstrated by casting polymeric films on the bottom of standard polypropylene microtiter plate wells (96 wells/plate). The modified microtiter plate optode format sensors exhibit response characteristics comparable to the classical optode films cast on quartz slides. The modified microtiter is utilized for the analysis of fluoride in diluted anti-cavity fluoride rinse

Design and construction of an optical sensor for liquid level control

International Nuclear Information System (INIS)

Razani, M.; Golnabi, H.; Dabbaghian, M. H.; Dariani, R. S.; Vaziri, N.; Hojabri, A.

2010-01-01

Design and construction of an optical sensor for liquid level control is reported here. Operation of this sensor is based on the intensity modulation. The modulated light intensity is detected by total internal reflection in a prism. The variation of output intensity is measured by an optical detector and is monitored by a digital voltmeter. This optical fiber sensor is used for water level measurement in this experiment. For a white light source, the output voltage in the case of low water level is equal to 480 mV and when the water level reaches to prism reduced to 8 mV. Height measurement accuracy in this system is about ±1mm.

Monitoring Ingress of Moisture in Structural Concrete Using a Novel Optical-Based Sensor Approach

International Nuclear Information System (INIS)

Yeo, T L; Cox, M A C; Boswell, L F; Sun, T; Grattan, K T V

2006-01-01

The detection of moisture ingress in concrete is important for structural monitoring and in this work is realised by monitoring the shift in the characteristic wavelength of a fibre Bragg grating-based sensor. The sensor relies upon a moisture-sensitive polymer layer deposited on the fibre Bragg grating (FBG) and the strain induced on it as a result of polymer swelling is monitored. Moisture ingress experiments were carried out using two such optical fibre sensors, placed at varying distances from the edge of the face of standard concrete cubes to the inner part of the concrete sample and subjected to water at a constant temperature. Information on the properties of different types of concrete and thus potentially on the migration of dissolved salts and their effect on reinforcement bars within concrete can be obtained

Wearable Optical Sensors

KAUST Repository

Ballard, Zachary S.; Ozcan, Aydogan

2017-01-01

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

A Lab-on-a-Chip-Based Non-Invasive Optical Sensor for Measuring Glucose in Saliva

Directory of Open Access Journals (Sweden)

Dong Geon Jung

2017-11-01

Full Text Available A lab-on-a-chip (LOC-based non-invasive optical sensor for measuring glucose in saliva was fabricated. Existing glucose sensors utilizing blood require acquisition of a blood sample by pricking the finger, which is painful and inconvenient. To overcome these limitations, we propose a non-invasive glucose sensor with LOC, micro-electro-mechanical system and optical measurement technology. The proposed sensor for measuring glucose in saliva involves pretreatment, mixing, and measurement on a single tiny chip. Saliva containing glucose and glucose oxidase for glucose oxidation are injected through Inlets 1 and 2, respectively. Next, H2O2 is produced by the reaction between glucose and glucose oxidase in the pretreatment part. The saliva and generated H2O2 are mixed with a colorizing agent injected through Inlet 3 during the mixing part and the absorbance of the colorized mixture is measured in the measurement part. The absorbance of light increases as a function of glucose concentration at a wavelength of 630 nm. To measure the absorbance of the colorized saliva, a light-emitting diode with a wavelength of 630 nm and a photodiode were used during the measurement part. As a result, the measured output current of the photodiode decreased as glucose concentration in the saliva increased.

Research on horizontal displacement monitoring of deep soil based on a distributed optical fibre sensor

Science.gov (United States)

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

2018-01-01

The traditional measurement method for the horizontal displacement of deep soil usually uses an inclinometer for piecewise measurement and then generates an artificial reading, which takes a long time and often contains errors; in addition, the anti-jamming and long-term stability of the inclinometer is poor. In this paper, a technique for monitoring horizontal displacement based on distributed optical fibres is introduced. The relationship between the strain and the deflection was described by a theoretical model, and the strain distribution of the inclinometer tube was measured by the cables laid on its surface so that the deflection of the inclinometer tube could be calculated by the difference algorithm and regarded as the horizontal displacement of deep soil. The horizontal displacement monitoring technology of deep soil based on distributed optical fibre sensors developed in this paper not only overcame the shortcomings of traditional inclinometer technology to realize automatic real-time monitoring but also allowed for distributed measurement. The experiment was similar to the expected engineering situations, and the deflection calculated from the strain was compared with an inclinometer. The results demonstrated that the relative error between the distributed optical fibre sensors and the inclinometer was less than 8.0%, and the results also verified both the feasibility of using distributed optical fibre to monitor the horizontal displacement of soil as well as the rationality of the theoretical model and difference algorithm. The application of distributed optical fibre in monitoring the horizontal displacement of deep soil in the engineering of foundation pits and slopes can more accurately evaluate the safety of engineering during construction.

Application of time-correlated single photon counting and stroboscopic detection methods with an evanescent-wave fibre-optic sensor for fluorescence-lifetime-based pH measurements

International Nuclear Information System (INIS)

Henning, Paul E; Geissinger, Peter

2012-01-01

Quasi-distributed optical fibre sensor arrays containing luminescent sensor molecules can be read out spatially resolved utilizing optical time-of-flight detection (OTOFD) methods, which employ pulsed laser interrogation of the luminosensors and time-resolved detection of the sensor signals. In many cases, sensing is based on a change in sensor luminescence intensity; however, sensing based on luminescence lifetime changes is preferable because it reduces the need for field calibration. Because in OTOFD detection is time-resolved, luminescence-lifetime information is already available through the signal pulses, although in practise applications were restricted to sensors with long luminescence lifetimes (hundreds of ns). To implement lifetime-based sensing in crossed-optical-fibre-sensor arrays for sensor molecules with lifetimes less than 10 ns, two time-domain methods, time-correlated single photon counting and stroboscopic detection, were used to record the pH-dependent emission of a fluorescein derivative covalently attached to a highly-porous polymer. A two-term nonexponential decay function yielded both a good fit for experimental lifetime data during reconvolution and a pH response that matches Henderson–Hasselbalch behaviour, yielding a sensor accuracy of 0.02 pH units. Moreover, strong agreement was obtained for the two lifetime determination methods and with intensity-based measurements taken previously. (paper)

CENTRAL WAVELENGTH ADJUSTMENT OF LIGHT EMITTING SOURCE IN INTERFEROMETRIC SENSORS BASED ON FIBER-OPTIC BRAGG GRATINGS

Directory of Open Access Journals (Sweden)

A. S. Aleynik

2015-09-01

Full Text Available The paper is focused on the investigation of fiber-optic interferometric sensor based on the array of fiber Bragg gratings. Reflection spectra displacement mechanism of the fiber Bragg gratings under the external temperature effects and the static pressure is described. The experiment has shown that reflection spectra displacement of Bragg gratings reduces the visibility of the interference pattern. A method of center wavelength adjustment is proposed for the optical radiation source in accord ance with the current Bragg gratings reflection spectra based on the impulse relative modulation of control signal for the Peltier element controller. The semiconductor vertical-cavity surface-emitting laser controlled by a pump driver is used as a light source. The method is implemented by the Peltier element controller regulating and stabilizing the light source temperature, and a programmable logic-integrated circuit monitoring the Peltier element controller. The experiment has proved that the proposed method rendered possible to regulate the light source temperature at a pitch of 0.05 K and adjust the optical radiation source center wavelength at a pitch of 0.05 nm. Experimental results have revealed that the central wavelength of the radiation adjustment at a pitch of 0.005 nm gives the possibility for the capacity of the array consisting of four opticalfiber sensors based on the fiber Bragg gratings. They are formed in one optical fiber under the Bragg grating temperature change from 0° C to 300° C and by the optical fiber mechanical stretching by the force up to 2 N.

Design and Optimization of Dual Optical Fiber MEMS Pressure Sensor For Biomedical Applications

International Nuclear Information System (INIS)

Dagang, Guo; Po, Samuel Ng Choon; Hock, Francis Tay Eng; Rongming, Lin

2006-01-01

A novel Single Deeply Corrugated Diaphragm (SDCD) based dual optical fiber Fabry-Perot pressure sensor for blood pressure measurement is proposed. Both mechanical and optical simulations are performed to demonstrate the feasibility and superior performance of the proposed sensor. Result shows that less than 2% nonlinearity can be achieved for the proposed sensor using optimal Fabry-Perot microcavity. Also, the fabrication process of the proposed sensor is given, instead of complicated fusion bonding process, only bulk and surface micromachining techniques are required which facilitate the mass production of such biocompatible and disposable pressure sensors

Optical and mechanical design of beam-target coupling sensor

International Nuclear Information System (INIS)

Wang Liquan; Li Tian'en; Feng Bin; Xiang Yong; Li Keyu; Zhong Wei; Liu Guodong

2012-01-01

A sensor based on conjugate principle has been designed for matching the light beams and the target in inertial confinement fusion. It can avoid the direct illumination of the simulation collimating light on the target under test in targeting processes. This paper introduces the optical and mechanical design of the sensor, according to its design functions and working principle. The resolution of the optical images obtained in experiments reaches 6 μm and the beam-target matching accuracy is 8.8 μm. The sensor has been successfully applied to the Shenguang-Ⅲ facility. Statistical analyses of the four-hole CH target images derived with pinhole camera shows that the targeting accuracy of the facility is better than 25 μm, satisfying the design requirements. (authors)

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

Porous Silicon Structures as Optical Gas Sensors.

Science.gov (United States)

Levitsky, Igor A

2015-08-14

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.

An Optical Fiber-Based Sensor Array for the Monitoring of Zinc and Copper Ions in Aqueous Environments

Directory of Open Access Journals (Sweden)

Steven Kopitzke

2014-02-01

Full Text Available Copper and zinc are elements commonly used in industrial applications as aqueous solutions. Before the solutions can be discharged into civil or native waterways, waste treatment processes must be undertaken to ensure compliance with government guidelines restricting the concentration of ions discharged in solution. While currently there are methods of analysis available to monitor these solutions, each method has disadvantages, be it high costs, inaccuracy, and/or being time-consuming. In this work, a new optical fiber-based platform capable of providing fast and accurate results when performing solution analysis for these metals is described. Fluorescent compounds that exhibit a high sensitivity and selectivity for either zinc or copper have been employed for fabricating the sensors. These sensors demonstrated sub-part-per-million detection limits, 30-second response times, and the ability to analyze samples with an average error of under 10%. The inclusion of a fluorescent compound as a reference material to compensate for fluctuations from pulsed excitation sources has further increased the reliability and accuracy of each sensor. Finally, after developing sensors capable of monitoring zinc and copper individually, these sensors are combined to form a single optical fiber sensor array capable of simultaneously monitoring concentration changes in zinc and copper in aqueous environments.

Fibre-optic temperature sensor

International Nuclear Information System (INIS)

Zhao Jie; Liu Zhenyuan.

1993-04-01

This experiment is a kind of nonfunction fibre-optic temperature sensor. It utilizes high-sensitive bimetallic strip for element of measuring temperature. The changing of bimetallic strip alterates intensity of light through fibre-optic. This equipment is simple in structure, subtle in design, extensive in application, and so on. (author). 4 refs, 6 figs, 1 tab

Particle-based optical pressure sensors for 3D pressure mapping.

Science.gov (United States)

Banerjee, Niladri; Xie, Yan; Chalaseni, Sandeep; Mastrangelo, Carlos H

2015-10-01

This paper presents particle-based optical pressure sensors for in-flow pressure sensing, especially for microfluidic environments. Three generations of pressure sensitive particles have been developed- flat planar particles, particles with integrated retroreflectors and spherical microballoon particles. The first two versions suffer from pressure measurement dependence on particles orientation in 3D space and angle of interrogation. The third generation of microspherical particles with spherical symmetry solves these problems making particle-based manometry in microfluidic environment a viable and efficient methodology. Static and dynamic pressure measurements have been performed in liquid medium for long periods of time in a pressure range of atmospheric to 40 psi. Spherical particles with radius of 12 μm and balloon-wall thickness of 0.5 μm are effective for more than 5 h in this pressure range with an error of less than 5%.

First experience with a novel luminescence-based optical sensor for measurement of oxygenation in tumors

International Nuclear Information System (INIS)

Jarm, T.; Miklavcic, D.; Lesnicar, H.; Sersa, G.

2001-01-01

Background. The purpose of this preliminary study was to evaluate a novel luminescence-based fiber-optic sensor (OxyLite system) for the measurement of partial pressure of oxygen (pO 2 ) in tumors and for the detection of changes in pO 2 as a function of time. The new method was used simultaneously with the laser Doppler flowmetry method for the measurement of relative tissue perfusion. Materials and methods. Blood perfusion and pO 2 were measured continuously via fiber-optic sensors inserted into SA-1 tumors in anesthetized A/J mice. The changes in blood flow and oxygenation of tumors were induced by transient changes of the parameters of anesthesia and by injection of a vasoactive drug hydralazine. Results. Both optical methods used in the study successfully detected the induced changes in blood flow and pO 2 . The measurements of pO 2 were well correlated with measurements of microcirculatory blood perfusion. In the majority of pO 2 measurements, we observed an unexpected behavior of the signal during the stabilization process immediately after the insertion of the probe into tumor. This behaviour of the pO 2 signal was most probably caused by local tissue damage induced by the insertion of the probe. Conclusion. The novel luminescence-based optical oximetry can reliably detect local pO 2 changes in tumors as a function of time but some aspects of prolonged pO 2 measurement by this method require further investigation. (author)

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...

Biological and chemical sensors based on graphene materials.

Science.gov (United States)

Liu, Yuxin; Dong, Xiaochen; Chen, Peng

2012-03-21

Owing to their extraordinary electrical, chemical, optical, mechanical and structural properties, graphene and its derivatives have stimulated exploding interests in their sensor applications ever since the first isolation of free-standing graphene sheets in year 2004. This article critically and comprehensively reviews the emerging graphene-based electrochemical sensors, electronic sensors, optical sensors, and nanopore sensors for biological or chemical detection. We emphasize on the underlying detection (or signal transduction) mechanisms, the unique roles and advantages of the used graphene materials. Properties and preparations of different graphene materials, their functionalizations are also comparatively discussed in view of sensor development. Finally, the perspective and current challenges of graphene sensors are outlined (312 references).

Corrosion induced strain monitoring through fibre optic sensors

International Nuclear Information System (INIS)

Grattan, S K T; Basheer, P A M; Taylor, S E; Zhao, W; Sun, T; Grattan, K T V

2007-01-01

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

Optical sensor for heat conduction measurement in biological tissue

International Nuclear Information System (INIS)

Gutierrez-Arroyo, A; Sanchez-Perez, C; Aleman-Garcia, N

2013-01-01

This paper presents the design of a heat flux sensor using an optical fiber system to measure heat conduction in biological tissues. This optoelectronic device is based on the photothermal beam deflection of a laser beam travelling in an acrylic slab this deflection is measured with a fiber optic angle sensor. We measure heat conduction in biological samples with high repeatability and sensitivity enough to detect differences in tissues from three chicken organs. This technique could provide important information of vital organ function as well as the detect modifications due to degenerative diseases or physical damage caused by medications or therapies.

Fiber optic particle plasmon resonance sensor based on plasmonic light scattering interrogation

International Nuclear Information System (INIS)

Lin, H.Y.; Huang, C.H.; Chau, L.K.

2012-01-01

A highly sensitive fiber optic particle plasmon resonance sensor (FO-PPR) is demonstrated for label-free biochemical detection. The sensing strategy relies on interrogating the plasmonic scattering of light from gold nanoparticles on the optical fiber in response to the surrounding refractive index changes or molecular binding events. The refractive index resolution is estimated to be 3.8 x 10 -5 RIU. The limit of detection for anti-DNP antibody spiked in buffer is 1.2 x 10 -9 g/ml (5.3 pM) by using the DNP-functionalized FO-PPR sensor. The image processing of simultaneously recorded plasmonic scattering photographs at different compartments of the sensor is also demonstrated. Results suggest that the compact sensor can perform multiple independent measurements simultaneously by means of monitoring the plasmonic scattering intensity via photodiodes or a CCD. The potential of using a combination of different kinds of noble metal nanoparticles with different types of functionalized probes in multiple cascaded detection windows on a single fiber to become an inexpensive and ultrasensitive linear-array sensing platform for higher-throughput biochemical detection is provided. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Optical bio-chemical sensors on SNOW ring resonators

Science.gov (United States)

Khorasaninejad, Mohammadreza; Clarke, Nigel; Anantram, M. P.; Singh Saini, Simarjeet

2011-08-01

In this paper, we propose and analyze novel ring resonator based bio-chemical sensors on silicon nanowire optical waveguide (SNOW) and show that the sensitivity of the sensors can be increased by an order of magnitude as compared to silicon-on-insulator based ring resonators while maintaining high index contrast and compact devices. The core of the waveguide is hollow and allows for introduction of biomaterial in the center of the mode, thereby increasing the sensitivity of detection. A sensitivity of 243 nm/refractive index unit (RIU) is achieved for a change in bulk refractive index. For surface attachment, the sensor is able to detect monolayer attachments as small as 1 Å on the surface of the silicon nanowires.

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.

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.

Non-contact optical Liquid Level Sensors

Science.gov (United States)

Kiseleva, L. L.; Tevelev, L. V.; Shaimukhametov, R. R.

2016-06-01

Information about characteristics of the optical liquid level sensor are present. Sensors are used to control of the light level limit fluid - water, kerosene, alcohol, solutions, etc. Intrinsically safe, reliable and easy to use. The operating principle of the level sensor is an optoelectronic infrared device.

Progress in triboluminescence-based smart optical sensor system

International Nuclear Information System (INIS)

Olawale, David O.; Dickens, Tarik; Sullivan, William G.; Okoli, Okenwa I.; Sobanjo, John O.; Wang, Ben

2011-01-01

Extensive research work has been done in recent times to apply the triboluminescence (TL) phenomenon for damage detection in engineering structures. Of particular note are the various attempts to apply it in the detection of impact damages in composites and aerospace structures. This is because TL-based sensor systems have a great potential for wireless, in-situ and distributed (WID) structural health monitoring when fully developed. This review article highlights development and the current state-of-the-art in the application of TL-based sensor systems. The underlying mechanisms believed to be responsible for triboluminescence, particularly in zinc sulfide manganese, a highly triboluminescent material, are discussed. The challenges militating against the full exploitation and field application of TL sensor systems are also identified. Finally, viable solutions and approaches to address these challenges are enumerated. - Highlights: → The underlying mechanisms believed to be responsible for triboluminescence. → State-of-the-art in the development and application of TL-based sensor systems. → The challenges militating against the full exploitation and field application of TL sensor systems are identified. → Viable solutions and approaches to address these challenges are enumerated.

Semiconductor sensor for optically measuring polarization rotation of optical wavefronts using rare earth iron garnets

Science.gov (United States)

Duncan, Paul G.

2002-01-01

Described are the design of a rare earth iron garnet sensor element, optical methods of interrogating the sensor element, methods of coupling the optical sensor element to a waveguide, and an optical and electrical processing system for monitoring the polarization rotation of a linearly polarized wavefront undergoing external modulation due to magnetic field or electrical current fluctuation. The sensor element uses the Faraday effect, an intrinsic property of certain rare-earth iron garnet materials, to rotate the polarization state of light in the presence of a magnetic field. The sensor element may be coated with a thin-film mirror to effectively double the optical path length, providing twice the sensitivity for a given field strength or temperature change. A semiconductor sensor system using a rare earth iron garnet sensor element is described.

Economical wireless optical ratiometric pH sensor

International Nuclear Information System (INIS)

Vuppu, Sandeep; Kostov, Yordan; Rao, Govind

2009-01-01

The development and application of a portable, wireless fluorescence-based optical pH sensor is presented. The design incorporates the MSP430 microcontroller as the control unit, an RF transceiver for wireless communication, digital filters and amplifiers and a USB-based communication module for data transmission. The pH sensor is based on ratiometric fluorescence detection from pH sensitive dye incorporated in a peel-and-stick patch. The ability of the instrument to detect the pH of the solution with contact only between the sensor patch and the solution makes it partially non-invasive. The instrument also has the ability to transmit data wirelessly, enabling its use in processes that entail stringent temperature control and sterility. The use of the microcontroller makes it a reliable, low-cost and low-power device. The luminous intensity of the light source can be digitally controlled to maximize the sensitivity of the instrument. It has a resolution of 0.05 pH. The sensor is accurate and reversible over the pH range of 6.5–9

Fluorescence based fibre optic pH sensor for the pH 10-13 range suitable for corrosion monitoring in concrete structures

OpenAIRE

Nguyen, T.H.; Venugopala, T.; Chen, S.; Sun, T.; Grattan, K. T. V.; Taylor, S.E.; Basheer, P.A.M.; Long, A.E.

2014-01-01

The design, development and evaluation of an optical fibre pH sensor for monitoring pH in the alkaline region are discussed in detail in this paper. The design of this specific pH sensor is based on the pH induced change in fluorescence intensity of a coumarin imidazole dye which is covalently attached to a polymer network and then fixed to the distal end of an optical fibre. The sensor provides a response over a pH range of 10.0 – 13.2 with an acceptable response rate of around 50 minutes, h...

Bragg Grating Based Sensors in Microstructured Polymer Optical Fibers: Accelerometers and Microphones

DEFF Research Database (Denmark)

Stefani, Alessio

With the growing interest towards fiber Bragg grating sensors and the growing ability in manufacturing polymer optical fibers, the development of polymer fiber Bragg sensors has catched the attention of industries with the goal of developing high performance sensors. This thesis presents...... and in microstructured fibers made of PMMA and TOPAS is reported. The gratings have been written at both 1550 nm, to take advantage of components made for telecommunications, and 850 nm, to exploit the lower loss of polymers and the fast acquisition electronics at this wavelength. A technique for writing multiplexed...

A fibre optic chemical sensor for the detection of cocaine

Science.gov (United States)

Nguyen, T. Hien; Sun, Tong; Grattan, Kenneth T. V.; Hardwick, S. A.

2010-09-01

A fibre-optic chemical sensor for the detection of cocaine has been developed, based on a molecularly imprinted polymer (MIP) containing a fluorescein moiety as the signalling group. The fluorescent MIP was formed and covalently attached to the distal end of an optical fibre. The sensor exhibited an increase in fluorescence intensity in response to cocaine in the concentration range of 0 - 500 μM in aqueous acetonitrile mixtures with good reproducibility over 24 h. Selectivity for cocaine over others drugs has also been demonstrated.

Characterization of Scintillating X-ray Optical Fiber Sensors

Science.gov (United States)

Sporea, Dan; Mihai, Laura; Vâţă, Ion; McCarthy, Denis; O'Keeffe, Sinead; Lewis, Elfed

2014-01-01

The paper presents a set of tests carried out in order to evaluate the design characteristics and the operating performance of a set of six X-ray extrinsic optical fiber sensors. The extrinsic sensor we developed is intended to be used as a low energy X-ray detector for monitoring radiation levels in radiotherapy, industrial applications and for personnel dosimetry. The reproducibility of the manufacturing process and the characteristics of the sensors were assessed. The sensors dynamic range, linearity, sensitivity, and reproducibility are evaluated through radioluminescence measurements, X-ray fluorescence and X-ray imaging investigations. Their response to the operating conditions of the excitation source was estimated. The effect of the sensors design and implementation, on the collecting efficiency of the radioluminescence signal was measured. The study indicated that the sensors are efficient only in the first 5 mm of the tip, and that a reflective coating can improve their response. Additional tests were done to investigate the concentricity of the sensors tip against the core of the optical fiber guiding the optical signal. The influence of the active material concentration on the sensor response to X-ray was studied. The tests were carried out by measuring the radioluminescence signal with an optical fiber spectrometer and with a Multi-Pixel Photon Counter. PMID:24556676

A microbent fiber optic pH sensor

NARCIS (Netherlands)

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

2002-01-01

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

Multimode-singlemode-multimode optical fiber sensor coated with novolac resin for detecting liquid phase alcohol

Science.gov (United States)

Marfu'ah, Amalia, Niza Rosyda; Hatta, Agus Muhamad; Pratama, Detak Yan

2018-04-01

Alcohol sensor based on multimode-singlemode-multimode (MSM) optical fiber with novolac resin as the external medium is proposed and demonstrated experimentally. Novolac resin swells when it is exposed by the alcohol. This effect causes a change in the polymer density leading to the refractive index's variation. The transmission light of the sensor depends on the refractive index of external medium. Based on the results, alcohol sensor based on MSM optical fiber structure using novolac resin has a higher sensitivity compared to the sensor without using novolac resin in the mixture of alcohol and distilled water. Alcohol sensor based on MSM optical fiber structure using novolac resin in the mixture of alcohol and distilled water with a singlemode fiber length of 5 mm has a sensitivity of 0.028972 dBm per % V/V, and in the mixture of alcohol and sugar solution of 10% w/w has a sensitivity of 0.005005 dBm per % V/V.

Highly sensitive digital optical sensor with large measurement range based on the dual-microring resonator with waveguide-coupled feedback

International Nuclear Information System (INIS)

Xiang Xing-Ye; Wang Kui-Ru; Yuan Jin-Hui; Jin Bo-Yuan; Sang Xin-Zhu; Yu Chong-Xiu

2014-01-01

We propose a novel high-performance digital optical sensor based on the Mach—Zehnder interferential effect and the dual-microring resonators with the waveguide-coupled feedback. The simulation results show that the sensitivity of the sensor can be orders of magnitude higher than that of a conventional sensor, and high quality factor is not critical in it. Moreover, by optimizing the length of the feedback waveguide to be equal to the perimeter of the ring, the measurement range of the proposed sensor is twice as much as that of the conventional sensor in the weak coupling case

Micro/Nanofibre Optical Sensors: Challenges and Prospects

Directory of Open Access Journals (Sweden)

Limin Tong

2018-03-01

Full Text Available Micro/nanofibres (MNFs are optical fibres with diameters close to or below the vacuum wavelength of visible or near-infrared light. Due to its wavelength- or sub-wavelength scale diameter and relatively large index contrast between the core and cladding, an MNF can offer engineerable waveguiding properties including optical confinement, fractional evanescent fields and surface intensity, which is very attractive to optical sensing on the micro and nanometer scale. In particular, the waveguided low-loss tightly confined large fractional evanescent fields, enabled by atomic level surface roughness and extraordinary geometric and material uniformity in a glass MNF, is one of its most prominent merits in realizing optical sensing with high sensitivity and great versatility. Meanwhile, the mesoporous matrix and small diameter of a polymer MNF, make it an excellent host fibre for functional materials for fast-response optical sensing. In this tutorial, we first introduce the basics of MNF optics and MNF optical sensors, and review the progress and current status of this field. Then, we discuss challenges and prospects of MNF sensors to some extent, with several clues for future studies. Finally, we conclude with a brief outlook for MNF optical sensors.

The Detection of Helicobacter hepaticus Using Whispering-Gallery Mode Microcavity Optical Sensors

Directory of Open Access Journals (Sweden)

Mark E. Anderson

2015-08-01

Full Text Available Current bacterial detection techniques are relatively slow, require bulky instrumentation, and usually require some form of specialized training. The gold standard for bacterial detection is culture testing, which can take several days to receive a viable result. Therefore, simpler detection techniques that are both fast and sensitive could greatly improve bacterial detection and identification. Here, we present a new method for the detection of the bacteria Helicobacter hepaticus using whispering-gallery mode (WGM optical microcavity-based sensors. Due to minimal reflection losses and low material adsorption, WGM-based sensors have ultra-high quality factors, resulting in high-sensitivity sensor devices. In this study, we have shown that bacteria can be non-specifically detected using WGM optical microcavity-based sensors. The minimum detection for the device was 1 × 104 cells/mL, and the minimum time of detection was found to be 750 s. Given that a cell density as low as 1 × 103 cells/mL for Helicobacter hepaticus can cause infection, the limit of detection shown here would be useful for most levels where Helicobacter hepaticus is biologically relevant. This study suggests a new approach for H. hepaticus detection using label-free optical sensors that is faster than, and potentially as sensitive as, standard techniques.

New radiological material detection technologies for nuclear forensics: Remote optical imaging and graphene-based sensors.

Energy Technology Data Exchange (ETDEWEB)

Harrison, Richard Karl [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Jeffrey B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wiemann, Dora K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Choi, Junoh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-09-01

We developed new detector technologies to identify the presence of radioactive materials for nuclear forensics applications. First, we investigated an optical radiation detection technique based on imaging nitrogen fluorescence excited by ionizing radiation. We demonstrated optical detection in air under indoor and outdoor conditions for alpha particles and gamma radiation at distances up to 75 meters. We also contributed to the development of next generation systems and concepts that could enable remote detection at distances greater than 1 km, and originated a concept that could enable daytime operation of the technique. A second area of research was the development of room-temperature graphene-based sensors for radiation detection and measurement. In this project, we observed tunable optical and charged particle detection, and developed improved devices. With further development, the advancements described in this report could enable new capabilities for nuclear forensics applications.

Micro-satellite for space debris observation by optical sensors

Science.gov (United States)

Thillot, Marc; Brenière, Xavier; Midavaine, Thierry

2017-11-01

The purpose of this theoretical study carried out under CNES contract is to analyze the feasibility of small space debris detection and classification with an optical sensor on-board micro-satellite. Technical solutions based on active and passive sensors are analyzed and compared. For the most appropriated concept an optimization was made and theoretical performances in terms of number of detection versus class of diameter were calculated. Finally we give some preliminary physical sensor features to illustrate the concept (weight, volume, consumption,…).

Study on the Sensing Coating of the Optical Fibre CO2 Sensor

Directory of Open Access Journals (Sweden)

Karol Wysokiński

2015-12-01

Full Text Available Optical fibre carbon dioxide (CO2 sensors are reported in this article. The principle of operation of the sensors relies on the absorption of light transmitted through the fibre by a silica gel coating containing active dyes, including methyl red, thymol blue and phenol red. Stability of the sensor has been investigated for the first time for an absorption based CO2 optical fiber sensor. Influence of the silica gel coating thickness on the sensitivity and response time has also been studied. The impact of temperature and humidity on the sensor performance has been examined too. Response times of reported sensors are very short and reach 2–3 s, whereas the sensitivity of the sensor ranges from 3 to 10 for different coating thicknesses. Reported parameters make the sensor suitable for indoor and industrial use.

Non-Invasive Optical Sensor Based Approaches for Monitoring Virus Culture to Minimize BSL3 Laboratory Entry

Directory of Open Access Journals (Sweden)

Viswanath Ragupathy

2015-06-01

Full Text Available High titers of infectious viruses for vaccine and diagnostic reference panel development are made by infecting susceptible mammalian cells. Laboratory procedures are strictly performed in a Bio-Safety Level-3 (BSL3 laboratory and each entry and exit involves the use of  disposable Personnel Protective Equipment (PPE to observe cell culture conditions. Routine PPE use involves significant recurring costs. Alternative non-invasive optical sensor based approaches to remotely monitor cell culture may provide a promising and cost effective approach to monitor infectious virus cultures resulting in lower disruption and costs. We report here the monitoring of high titer cultures of Human Immunodeficiency Virus-1 (HIV-1 and Herpes Simplex Virus-2 (HSV-2 remotely with the use of optical oxygen sensors aseptically placed inside the cell culture vessel. The replacement of culture media for cell and virus propagation and virus load monitoring was effectively performed using this fluorescent sensor and resulted in half the number of visits to the BSL3 lab (five versus ten.

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.

Linearization of Positional Response Curve of a Fiber-optic Displacement Sensor

Science.gov (United States)

Babaev, O. G.; Matyunin, S. A.; Paranin, V. D.

2018-01-01

Currently, the creation of optical measuring instruments and sensors for measuring linear displacement is one of the most relevant problems in the area of instrumentation. Fiber-optic contactless sensors based on the magneto-optical effect are of special interest. They are essentially contactless, non-electrical and have a closed optical channel not subject to contamination. The main problem of this type of sensors is the non-linearity of their positional response curve due to the hyperbolic nature of the magnetic field intensity variation induced by moving the magnetic source mounted on the controlled object relative to the sensing element. This paper discusses an algorithmic method of linearizing the positional response curve of fiber-optic displacement sensors in any selected range of the displacements to be measured. The method is divided into two stages: 1 - definition of the calibration function, 2 - measurement and linearization of the positional response curve (including its temperature stabilization). The algorithm under consideration significantly reduces the number of points of the calibration function, which is essential for the calibration of temperature dependence, due to the use of the points that randomly deviate from the grid points with uniform spacing. Subsequent interpolation of the deviating points and piecewise linear-plane approximation of the calibration function reduces the microcontroller storage capacity for storing the calibration function and the time required to process the measurement results. The paper also presents experimental results of testing real samples of fiber-optic displacement sensors.

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

Science.gov (United States)

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

2013-12-01

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

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.

Review of high bandwidth fiber optics radiation sensors

International Nuclear Information System (INIS)

Lyons, P.B.

1985-01-01

This paper summarizes the use of fiber optics or guided optical systems for radiation sensors. It is limited a passive systems wherein electrical is not required at the sensor location. However, electrically powered light sources, receivers and/or recorders may still be required for detection and data storage in sensor system operation. This paper emphasizes sensor technologies that permit high bandwidth measurements of transient radiation levels, and will also discuss several low bandwidth applications. 60 refs

Fiber-Optic Continuous Liquid Sensor for Cryogenic Propellant Gauging

Science.gov (United States)

Xu. Wei

2010-01-01

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

Graphene based chalcogenide fiber-optic evanescent wave sensor for detection of hemoglobin in human blood

Science.gov (United States)

Sharma, Anuj K.; Gupta, Jyoti

2018-03-01

Fiber optic evanescent wave sensor with graphene as an absorption-enhancing layer to measure hemoglobin concentration in human blood is proposed. Previous modal functions and experimental results describing the variation of optical constants of human blood with different hemoglobin concentrations in the near-infrared spectral region are considered for sensor design simulation. The sensor's performance is closely analyzed in terms of its absorption coefficient, sensitivity, and detection limit. It is found that the proposed sensor should be operated at longer light wavelength to get more enhanced sensitivity and smaller detection limit. At 1000 nm wavelength, a detection limit of 18 μg/dL and sensitivity of 6.71 × 10-4 per g/dL is achievable with the proposed sensor. The sensitivity is found to be better for larger hemoglobin concentrations. The results are correlated with the evanescent wave penetration depth.

Design and synthesis of a fluorescent molecular imprinted polymer for use in an optical fibre-based cocaine sensor

Science.gov (United States)

Wren, Stephen P.; Piletsky, Sergey A.; Karim, Kal; Gascoine, Paul; Lacey, Richard; Sun, Tong; Grattan, Kenneth T. V.

2014-05-01

Previously, we have developed chemical sensors using fibre optic-based techniques for the detection of Cocaine, utilising molecularly imprinted polymers (MIPs) containing fluorescein moieties as the signalling groups. Here, we report the computational design of a fluorophore which was incorporated into a MIP for the generation of a novel sensor that offers improved sensitivity for Cocaine with a detection range of 1-100μM. High selectivity for Cocaine over a suite of known Cocaine interferants (25μM) was also demonstrated by measuring changes in the intensity of fluorescence signals received from the sensor.

Preparation of a novel pH optical sensor using orange (II) based on agarose membrane as support.

Science.gov (United States)

Heydari, Rouhollah; Hosseini, Mohammad; Amraei, Ahmadreza; Mohammadzadeh, Ali

2016-04-01

A novel and cost effective optical pH sensor was prepared using covalent immobilization of orange (II) indicator on the agarose membrane as solid support. The fabricated optical sensor was fixed into a sample holder of a spectrophotometer instrument for pH monitoring. Variables affecting sensor performance including pH of dye bonding to agarose membrane and dye concentration were optimized. The sensor responds to the pH changes in the range of 3.0-10.0 with a response time of 2.0 min and appropriate reproducibility (RSD ≤ 0.9%). No significant variation was observed on sensor response after increasing the ionic strength in the range of 0.0-0.5M of sodium chloride. Determination of pH using the proposed optical sensor is quick, simple, inexpensive, selective and sensitive in the pH range of 3.0-10.0. Copyright © 2015 Elsevier B.V. All rights reserved.

A novel mechano-optical sensor based on read-out with a Si3N4 grated waveguide

NARCIS (Netherlands)

Pham Van So, P.V.S.; Dijkstra, Mindert; van Wolferen, Hendricus A.G.M.; Pollnau, Markus; Krijnen, Gijsbertus J.M.; Hoekstra, Hugo

2011-01-01

Microcantilever-based sensors can be used to detect molecular absorption of, for example, hydrogen gas, which causes changes in the surface stress, leading to deflection of the cantilever. Such a deflection can be determined by means of optical beam deflection, capacitance-, or piezo-resistance

Vision communications based on LED array and imaging sensor

Science.gov (United States)

Yoo, Jong-Ho; Jung, Sung-Yoon

2012-11-01

In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

Radiation tolerant fiber optic humidity sensors for High Energy Physics applications

CERN Document Server

Berruti, Gaia Maria; Cusano, Andrea

This work is devoted to the development of fiber optic humidity sensors to be applied in high-energy physics applications and in particular in experiments currently running at CERN. The high radiation level resulting from the operation of the accelerator at full luminosity can cause serious performance deterioration of the silicon sensors which are responsible for the particle tracking. To increase their lifetime, the sensors must be kept cold at temperatures below 0 C. At such low temperatures, any condensation risk has to be prevented and a precise thermal and hygrometric control of the air filling and surrounding the tracker detector cold volumes is mandatory. The technologies proposed at CERN for relative humidity monitoring are mainly based on capacitive sensing elements which are not designed with radiation resistance characteristic. In this scenario, fiber optic sensors seem to be perfectly suitable. Indeed, the fiber itself, if properly selected, can tolerate a very high level of radiation, optical fi...

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

DEFF Research Database (Denmark)

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

2016-01-01

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....... 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...

Fast and long term optical sensors for pH based on sol-gels

International Nuclear Information System (INIS)

Wang Enju; Chow, Kwok-Fan; Kwan, Vivian; Chin, Tammy; Wong, Crystal; Bocarsly, Andrew

2003-01-01

Long lasting and fast response optical sensor for the detection of pH in the range of 6-12 is described. The sensor is fabricated by spin coating silica sol in the presence of phenol red (PR). The sol is in turn obtained by acidic hydrolysis of tetraethoxysilane (TEOS) and phenyltriethoxysilane (Ph-TriEOS). The performance of the sensor depends on the ratio of Ph-TriOES to TEOS. At the optimal composition, the sensor has a response time of less than 20 s, the response is completely reversible and its life-time is over 12 months

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.

Miniature all-silica optical fiber pressure sensor with an ultrathin uniform diaphragm.

Science.gov (United States)

Wang, Wenhui; Wu, Nan; Tian, Ye; Niezrecki, Christopher; Wang, Xingwei

2010-04-26

This paper presents an all-silica miniature optical fiber pressure/acoustic sensor based on the Fabry-Perot (FP) interferometric principle. The endface of the etched optical fiber tip and silica thin diaphragm on it form the FP structure. The uniform and thin silica diaphragm was fabricated by etching away the silicon substrate from a commercial silicon wafer that has a thermal oxide layer. The thin film was directly thermally bonded to the endface of the optical fiber thus creating the Fabry-Perot cavity. Thin films with a thickness from 1microm to 3microm have been bonded successfully. The sensor shows good linearity and hysteresis during measurement. A sensor with 0.75 microm-thick diaphragm thinned by post silica etching was demonstrated to have a sensitivity of 11 nm/kPa. The new sensor has great potential to be used as a non-intrusive pressure sensor in a variety of sensing applications.

Temperature measurement distributed on a building by fiber optic BOTDA sensor

International Nuclear Information System (INIS)

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

2002-01-01

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

Sensitive zone parameters and curvature radius evaluation for polymer optical fiber curvature sensors

Science.gov (United States)

Leal-Junior, Arnaldo G.; Frizera, Anselmo; José Pontes, Maria

2018-03-01

Polymer optical fibers (POFs) are suitable for applications such as curvature sensors, strain, temperature, liquid level, among others. However, for enhancing sensitivity, many polymer optical fiber curvature sensors based on intensity variation require a lateral section. Lateral section length, depth, and surface roughness have great influence on the sensor sensitivity, hysteresis, and linearity. Moreover, the sensor curvature radius increase the stress on the fiber, which leads on variation of the sensor behavior. This paper presents the analysis relating the curvature radius and lateral section length, depth and surface roughness with the sensor sensitivity, hysteresis and linearity for a POF curvature sensor. Results show a strong correlation between the decision parameters behavior and the performance for sensor applications based on intensity variation. Furthermore, there is a trade-off among the sensitive zone length, depth, surface roughness, and curvature radius with the sensor desired performance parameters, which are minimum hysteresis, maximum sensitivity, and maximum linearity. The optimization of these parameters is applied to obtain a sensor with sensitivity of 20.9 mV/°, linearity of 0.9992 and hysteresis below 1%, which represent a better performance of the sensor when compared with the sensor without the optimization.

Bullet Optical Fiber Humidity Sensor Based on Ag Nanoparticles Dispersed in Leaf Extract of Alstonia Scholaris

Directory of Open Access Journals (Sweden)

Anu VIJAYAN

2008-05-01

Full Text Available An optical fiber with a clad of Ag nanoparticles dispersed in leaf extract of Alstonia Scholaris is used as an optical humidity sensor. The fabricated sensor showed response to humidity in the range of 40-95%. The specialty of this sensor is that it can be used when stored at room temperature (25 oC up to a maximum of 25 days with 90% retention of original sensitivity. These humidity sensing bio-films showed good operational efficiency for 5 cycles. The plastic optical fiber is versatile and can be used easily for humidity measurement with high sensitivity. The sensor exhibited a short response time of 4-5 sec. and recovery time of 45 sec with repeatability, reproducibility and low hysteresis effect. This Ag dispersed in leaf extract of Alstonia Scholaris showed higher humidity response compared to response shown by the leaf extract alone.

An Optical Fibre Depth (Pressure) Sensor for Remote Operated Vehicles in Underwater Applications

Science.gov (United States)

Duraibabu, Dinesh Babu; Poeggel, Sven; Omerdic, Edin; Capocci, Romano; Lewis, Elfed; Newe, Thomas; Leen, Gabriel; Toal, Daniel; Dooly, Gerard

2017-01-01

A miniature sensor for accurate measurement of pressure (depth) with temperature compensation in the ocean environment is described. The sensor is based on an optical fibre Extrinsic Fabry-Perot interferometer (EFPI) combined with a Fibre Bragg Grating (FBG). The EFPI provides pressure measurements while the Fibre Bragg Grating (FBG) provides temperature measurements. The sensor is mechanically robust, corrosion-resistant and suitable for use in underwater applications. The combined pressure and temperature sensor system was mounted on-board a mini remotely operated underwater vehicle (ROV) in order to monitor the pressure changes at various depths. The reflected optical spectrum from the sensor was monitored online and a pressure or temperature change caused a corresponding observable shift in the received optical spectrum. The sensor exhibited excellent stability when measured over a 2 h period underwater and its performance is compared with a commercially available reference sensor also mounted on the ROV. The measurements illustrates that the EFPI/FBG sensor is more accurate for depth measurements (depth of ~0.020 m). PMID:28218727

Fiber-based optic sensor for detecting human blood clot: present and future revival

Science.gov (United States)

Elshikeri, Nada; Bakhtiar, Hazri

2018-05-01

Sustaining human’s life-frame away from being impeded by the clot - ghost term, we attempt to approach a mobile fiber-based optical sensor (f-s) for detecting blood clot in a blood vessel (intra-arteries/veins). Blood vessels are the part of the circulatory system that transport blood throughout the human body, thus their significance of being protected arise to the monograph focus. MRI (magnetic resonance imaging), X-rays and other medical instruments are diagnostic immobility techniques with a slackest interval. The corer causation of fiber-based optical sensor is to detect a clump of blood in the bloodstream by providing a prompt mobile diagnostic intervals preserving last-minutes-breath of human’s life. The detector (f-s) has been etched by diluting sulphuric acid ~10% at certain zone to sensate its function. The in-vitro monograph peaks its maximal monitoring when the sensor is attached to Raman Spectroscopy (RS) setup. RS quantifies the relative intensities of fibrinogen bond, which is the first type of blood coagulation elements of blood plasma. Blood coagulation parameters are the major concern of the monograph investigation, such as total haemoglobin (tHb), clotting reaction time (t), clot progression time (t2), maximum clot amplitude (ma) and mean refractive index (r). A blood sample will be drawn from the patient and after centrifugation to separate blood plasma from its constituents, then an immediate sloshing of blood plasma in the (f-s) packet which has its plug-in to RS. Estimating the quantitative analysis of blood sample concentration, RS will determine the presence of coagulation in terms of intensity and medical procedures will dominate the treatment process. Thus, the suggestive monograph provides a definite instrument for investigating blood coagulation intra-arteries/veins promptly.

Development of a position sensor based on a four quadrant structured optic fiber bundle

International Nuclear Information System (INIS)

Boukellal, Younes; Ducourtieux, Sebastien

2015-01-01

This article reports on the development of a new kind of 2D displacement sensor based on an optic fiber bundle whose fiber arrangement has been customized to provide an input sensitive surface with four quadrants. The fibers of each quadrant are regrouped to form four output arms. The aim is to reach behavior similar to that of a quad cell photodiode when illuminated by a laser spot. In this paper, we present the motivations for developing such a sensor and its design. Prior to the fabrication of a first prototype, the optic fiber bundle has been modelled and compared to a quad cell photodiode. It has an active surface which is 10 mm in diameter and which comprises 40 000 fibers of 50 µm core diameter. For this experimental test, a specific electronic conditioning circuit has been developed to process the signals. From both modelled and experimental results, fiber optic bundle and quad cell photodiode behavior has proved to be very similar, provided that the number of fibers is sufficient to achieve a statistical effect on the detected displacement, i.e. the laser spot diameter is rightly chosen as a function of the fiber diameter. For the use of the bundle as position sensor, a laser spot size of 5 mm has been fixed to achieve a good compromise between sensitivity and displacement range. With this spot size, sensitivity and displacement range have been experimentally evaluated to 2 mV µm −1 and 3.8 mm respectively with a corresponding displacement resolution of 5 nm in the best case. (paper)

Optical and Electronic NO(x) 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 NO(x) 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 NO(x) 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 NO(x) 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 NO(x) sensor platform characterized by high conductivity, corrosion resistance, and strong surface state coupling.

Optical sensor for real-time weld defect detection

Science.gov (United States)

Ancona, Antonio; Maggipinto, Tommaso; Spagnolo, Vincenzo; Ferrara, Michele; Lugara, Pietro M.

2002-04-01

In this work we present an innovative optical sensor for on- line and non-intrusive welding process monitoring. It is based on the spectroscopic analysis of the optical VIS emission of the welding plasma plume generated in the laser- metal interaction zone. Plasma electron temperature has been measured for different chemical species composing the plume. Temperature signal evolution has been recorded and analyzed during several CO2-laser welding processes, under variable operating conditions. We have developed a suitable software able to real time detect a wide range of weld defects like crater formation, lack of fusion, excessive penetration, seam oxidation. The same spectroscopic approach has been applied for electric arc welding process monitoring. We assembled our optical sensor in a torch for manual Gas Tungsten Arc Welding procedures and tested the prototype in a manufacturing industry production line. Even in this case we found a clear correlation between the signal behavior and the welded joint quality.

A Novel Optical Morse Code-Based Electronic Lock Using the Ambient Light Sensor and Fuzzy Controller

Directory of Open Access Journals (Sweden)

Chin-Tan Lee

2017-02-01

Full Text Available In this work, a novel electronic lock that can encode and decode optical signals, modulated using Morse code conventions, was developed to build a smart home security system based on the Internet of Things (IoT. There are five topics of interest in this research: (1 optical Morse code encoder; (2 optical Morse code decoder; (3 ambient light sensor circuit; (4 fuzzy controller; (5 cloud monitoring system. We take advantage of the light-emitting components as the encoder, which are readily available in hand-held mobile devices (e.g., Smart phones and photoresistors and a microcontroller as the decoder. By Wi-Fi transferring, even without a personal computer, real-time information about this lock can be uploaded to the cloud service platform, and helps users to ensure home safety on the remote monitoring system. By using the ambient light sensor and fuzzy controller in this novel optical Morse code-based electronic lock, experimental results show that the reliability of this system is much improved from 65% to 100%. That means that it is highly resistant to different illumination conditions in the work environment, and therefore all functions, including coding, emitting, receiving, decoding, uploading and cloud monitoring, can work well. Furthermore, besides the convenience and cost reduction, by incorporating traditional keys into smart phones, as a consumer electronics, our proposed system is suitable for users of all ages because of a user-friendly operation interface.

Electro-optic architecture (EOA) for sensors and actuators in aircraft propulsion systems

Science.gov (United States)

Glomb, W. L., Jr.

1989-01-01

Results of a study to design an optimal architecture for electro-optical sensing and control in advanced aircraft and space systems are described. The propulsion full authority digital Electronic Engine Control (EEC) was the focus for the study. The recommended architecture is an on-engine EEC which contains electro-optic interface circuits for fiber-optic sensors on the engine. Size and weight are reduced by multiplexing arrays of functionally similar sensors on a pair of optical fibers to common electro-optical interfaces. The architecture contains common, multiplex interfaces to seven sensor groups: (1) self luminous sensors; (2) high temperatures; (3) low temperatures; (4) speeds and flows; (5) vibration; (6) pressures; and (7) mechanical positions. Nine distinct fiber-optic sensor types were found to provide these sensing functions: (1) continuous wave (CW) intensity modulators; (2) time division multiplexing (TDM) digital optic codeplates; (3) time division multiplexing (TDM) analog self-referenced sensors; (4) wavelength division multiplexing (WDM) digital optic code plates; (5) wavelength division multiplexing (WDM) analog self-referenced intensity modulators; (6) analog optical spectral shifters; (7) self-luminous bodies; (8) coherent optical interferometers; and (9) remote electrical sensors. The report includes the results of a trade study including engine sensor requirements, environment, the basic sensor types, and relevant evaluation criteria. These figures of merit for the candidate interface types were calculated from the data supplied by leading manufacturers of fiber-optic sensors.

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

Science.gov (United States)

Tosi, Daniele

2015-01-01

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

Analytical analysis of sensitivity of optical waveguide sensor

African Journals Online (AJOL)

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Section 2 provides the principle and basic theory of optical sensors and the modal ... this paper for optical sensor, a chemically selective layer or adlayer is ... Applying boundary condition at n1/n2 and n1/n3 the interface, and using the above.

Advances in hybrid optics physical sensors for extreme environments

Science.gov (United States)

Riza, Nabeel A.

2010-04-01

Highlighted are novel innovations in hybrid optical design physical sensors for extreme environments. Various hybrid design compositions are proposed that are suited for a particular sensor application. Examples includes combining freespace (wireless) and fiber-optics (wired) for gas turbine sensing and combining single crystal and sintered Silicon Carbide (SiC) materials for robust extreme environment Coefficent of Thermal Expansion (CTE) matched frontend probe design. Sensor signal processing also includes the hybrid theme where for example Black-Body radiation thermometry (pyrometry) is combined with laser interferometry to provide extreme temperature measurements. The hybrid theme also operates on the optical device level where a digital optical device such as a Digital Micromirror Device (DMD) is combined with an analog optical device such as an Electronically Controlled Variable Focal Length Lens (ECVFL) to deliver a smart and compressive Three Dimensional (3-D) imaging sensor for remote scene and object shape capture including both ambient light (passive) mode and active laser targeting and receive processing. Within a device level, the hybrid theme also operates via combined analog and digital control such as within a wavelength-coded variable optical delay line. These powerful hybrid design optical sensors have numerous applications in engineering and science applications from the military to the commercial/industrial sectors.