scholarly journals High-Sensitivity Fiber-Optic Ultrasound Sensors for Medical Imaging Applications

1998 ◽  
Vol 20 (2) ◽  
pp. 103-112 ◽  
Author(s):  
H. Wen ◽  
D.G. Wiesler ◽  
A. Tveten ◽  
B. Danver ◽  
A. Dandridge
Keyword(s):  
Medical Imaging ◽  
Optical Fibers ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
High Sensitivity ◽  
Single Mode ◽  
Piezoelectric Sensors ◽  
Single Element ◽  
Bending Radius ◽  
Laser Interferometers

This paper presents several designs of high-sensitivity, compact fiber-optic ultrasound sensors that may be used for medical imaging applications. These sensors translate ultrasonic pulses into strains in single-mode optical fibers, which are measured with fiber-based laser interferometers at high precision. The sensors are simpler and less expensive to make than piezoelectric sensors, and are not susceptible to electromagnetic interference. It is possible to make focal sensors with these designs, and several schemes are discussed. Because of the minimum bending radius of optical fibers, the designs are suitable for single element sensors rather than for arrays.

scholarly journals Liquid crystal cell with a tapered optical fiber as an active element to optical applications

2019 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Joanna Ewa Moś ◽  
Karol Antoni Stasiewicz ◽  
Leszek Roman Jaroszewicz
Keyword(s):  
Liquid Crystal ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
High Sensitivity ◽  
Single Mode ◽  
Fiber Optic Sensors ◽  
Liquid Crystal Cell ◽  
Crystal Cell ◽  
Tapered Optical Fiber

The work describes the technology of a liquid crystal cell with a tapered optical fiber as an element providing light. The tapered optical fiber with the total optical loss of 0.22 ± 0.07 dB, the taper waist diameter of 15.5 ± 0.5 μm, and the elongation of 20.4 ± 0.3 mm has been used. The experimental results are presented for a liquid crystal cell filled with a mixture 1550* for parallel orientation of LC molecules to the cross section of the taper waist. Measurement results show the influence of the electrical field with voltage in the range of 0-200 V, without, as well as with different modulation for spectral characteristics. The sinusoidal and square signal shapes are used with a 1-10 Hz frequency range. Full Text: PDF ReferencesZ. Liu, H. Y. Tam, L. Htein, M. L.Vincent Tse, C. Lu, "Microstructured Optical Fiber Sensors", J. Lightwave Technol. 35, 16 (2017). CrossRef T. R. Wolinski, K. Szaniawska, S. Ertman1, P. Lesiak, A. W. Domański, R. Dabrowski, E. Nowinowski-Kruszelnicki, J. Wojcik "Influence of temperature and electrical fields on propagation properties of photonic liquid-crystal fibres", Meas. Sci. Technol. 17, 5 (2006). CrossRef K. Nielsen, D. Noordegraaf, T. Sørensen, A. Bjarklev,T. Hansen, "Selective filling of photonic crystal fibres", J. Opt. A: Pure Appl. Opt. 7, 8 (2005). CrossRef A. A. Rifat, G. A. Mahdiraji, D. M. Chow, Y, Gang Shee, R. Ahmed, F. Rafiq, M Adikan, "Photonic Crystal Fiber-Based Surface Plasmon Resonance Sensor with Selective Analyte Channels and Graphene-Silver Deposited Core", Sensors 15, 5 (2015) CrossRef Y. Huang, Z.Tian, L.P. Sun, D. Sun, J.Li, Y.Ran, B.-O. Guan "High-sensitivity DNA biosensor based on optical fiber taper interferometer coated with conjugated polymer tentacle", Opt. Express 23, 21 (2015). CrossRef X. Wang, O. S. Wolfbeis, "The 2016 Annual Review Issue", Anal. Chem., 88, 1 (2016). CrossRef Ye Tian, W. Wang, N. Wu, X. Zou, X.Wang, "Tapered Optical Fiber Sensor for Label-Free Detection of Biomolecules", Sensors 11, 4 (2011). CrossRef O. Katsunari, Fundamentals of Optical Waveguides, (London, Academic Press, (2006). DirectLink A. K. Sharma, J. Rajan, B.D. Gupta, "Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review", IEEE Sensors Journal 7, 8 (2007). CrossRef C. Caucheteur, T. Guo, J. Albert, "Review of plasmonic fiber optic biochemical sensors: improving the limit of detection", Anal. Bioanal.Chem. 407, 14 (2015). CrossRef S. F. Silva L. Coelho, O. Frazão, J. L. Santos, F. X.r Malcata, "A Review of Palladium-Based Fiber-Optic Sensors for Molecular Hydrogen Detection", IEEE SENSORS JOURNAL 12, 1 (2012). CrossRef H. Waechter, J. Litman, A. H. Cheung, J. A. Barnes, H.P. Loock, "Chemical Sensing Using Fiber Cavity Ring-Down Spectroscopy", Sensors 10, 3 (2010). CrossRef S. Zhu, F. Pang, S. Huang, F.Zou, Y.Dong, T.Wang, "High sensitivity refractive index sensor based on adiabatic tapered optical fiber deposited with nanofilm by ALD", Opt. Express 23, 11 (2015). CrossRef L. Zhang, J. Lou, L. Tong, "Micro/nanofiber optical sensors", Photonics sensor 1, 1 (2011). CrossRef L.Tong, J. Lou, E. Mazur, "Single-mode guiding properties of subwavelength-diameter silica and silicon wire waveguides", Opt. Express 11, 6 (2004). CrossRef H. Moyyed, I. T. Leite, L. Coelho, J. L. Santos, D. Viegas, "Analysis of phase interrogated SPR fiber optic sensors with bimetallic layers", IEEE Sensors Journal 14, 10 (2014). CrossRef A. González-Cano, M. Cruz Navarette, Ó. Esteban, N. Diaz Herrera , "Plasmonic sensors based on doubly-deposited tapered optical fibers", Sensors 14, 3 (2014). CrossRef K. A. Stasiewicz, J.E. Moś, "Threshold temperature optical fibre sensors", Opt. Fiber Technol. 32, (2016). CrossRef L. Zhang, F. Gu, J. Lou, X. Yin, L. Tong, "Fast detection of humidity with a subwavelength-diameter fiber taper coated with gelatin film", Opt. Express 16, 17 (2008). CrossRef S.Zhu, F.Pang, S. Huang, F. Zou, Q. Guo, J. Wen, T. Wang, "High Sensitivity Refractometer Based on TiO2-Coated Adiabatic Tapered Optical Fiber via ALD Technology", Sensors 16, 8 (2016). CrossRef G.Brambilla, "Optical fibre nanowires and microwires: a review", J. Optics 12, 4 (2010) CrossRef M. Ahmad, L.L. Hench, "Effect of taper geometries and launch angle on evanescent wave penetration depth in optical fibers", Biosens. Bioelectron. 20, 7 (2005). CrossRef L.M. Blinov, Electrooptic Effects in Liquid Crystal Materials (New York, Springftianer, 1994). CrossRef L. Scolari, T.T. Alkeskjold, A. Bjarklev, "Tunable Gaussian filter based on tapered liquid crystal photonic bandgap fibre", Electron. Lett. 42, 22 (2006). CrossRef J. Moś, M. Florek, K. Garbat, K.A. Stasiewicz, N. Bennis, L.R. Jaroszewicz, "In-Line Tunable Nematic Liquid Crystal Fiber Optic Device", J. of Lightwave Technol. 36, 4 (2017). CrossRef J. Moś, K A Stasiewicz, K Garbat, P Morawiak, W Piecek, L R Jaroszewicz, "Tapered fiber liquid crystal hybrid broad band device", Phys. Scripta. 93, 12 (2018). CrossRef Ch. Veilleux, J. Lapierre, J. Bures, "Liquid-crystal-clad tapered fibers", Opt. Lett. 11, 11 (1986). CrossRef R. Dąbrowski, K. Garbat, S. Urban, T.R. Woliński, J. Dziaduszek, T. Ogrodnik, A,Siarkowska, "Low-birefringence liquid crystal mixtures for photonic liquid crystal fibres application", Liq. Cryst. 44, (2017). CrossRef S. Lacroix, R. J. Black, Ch. Veilleux, J. Lapierre, "Tapered single-mode fibers: external refractive-index dependence", Appl. Opt., 25, 15 (1986). CrossRef J.F. Henninot, D. Louvergneaux , N.Tabiryan, M. Warenghem, "Controlled Leakage of a Tapered Optical Fiber with Liquid Crystal Cladding", Mol. Cryst.and Liq.Cryst., 282, 1(1996). CrossRef

scholarly journals Fiber Optic Sensors for Vital Signs Monitoring. A Review of Its Practicality in the Health Field

Biosensors ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 58
Author(s):  
Christian Perezcampos Mayoral ◽  
Jaime Gutiérrez Gutiérrez ◽  
José Luis Cano Pérez ◽  
Marciano Vargas Treviño ◽  
Itandehui Belem Gallegos Velasco ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
Life Support ◽  
Vital Signs ◽  
Visible Spectrum ◽  
Single Mode ◽  
Fiber Optic Sensors ◽  
Vital Signs Monitoring

Vital signs not only reflect essential functions of the human body but also symptoms of a more serious problem within the anatomy; they are well used for physical monitoring, caloric expenditure, and performance before a possible symptom of a massive failure—a great variety of possibilities that together form a first line of basic diagnosis and follow-up on the health and general condition of a person. This review includes a brief theory about fiber optic sensors’ operation and summarizes many research works carried out with them in which their operation and effectiveness are promoted to register some vital sign(s) as a possibility for their use in the medical, health care, and life support fields. The review presents methods and techniques to improve sensitivity in monitoring vital signs, such as the use of doping agents or coatings for optical fiber (OF) that provide stability and resistance to the external factors from which they must be protected in in vivo situations. It has been observed that most of these sensors work with single-mode optical fibers (SMF) in a spectral range of 1550 nm, while only some work in the visible spectrum (Vis); the vast majority, operate through fiber Bragg gratings (FBG), long-period fiber gratings (LPFG), and interferometers. These sensors have brought great advances to the measurement of vital signs, especially with regard to respiratory rate; however, many express the possibility of monitoring other vital signs through mathematical calculations, algorithms, or auxiliary devices. Their advantages due to miniaturization, immunity to electromagnetic interference, and the absence of a power source makes them truly desirable for everyday use at all times.

High-voltage monitoring by the fiber-optic recirculating measuring system

2020 ◽  
pp. 38-44
Author(s):  
A. V. Polyakov ◽  
M. A. Ksenofontov
Keyword(s):  
Optical Fibers ◽  
High Voltage ◽  
Optical Sensors ◽  
Electromagnetic Interference ◽  
Fiber Optic ◽  
Electric Power Industry ◽  
Measuring System ◽  
Voltage Range ◽  
External Electromagnetic Fields ◽  
Optic Communication

Optical technologies for measuring electrical quantities attract great attention due to their unique properties and significant advantages over other technologies used in high-voltage electric power industry: the use of optical fibers ensures high stability of measuring equipment to electromagnetic interference and galvanic isolation of high-voltage sensors; external electromagnetic fields do not influence the data transmitted from optical sensors via fiber-optic communication lines; problems associated with ground loops are eliminated, there are no side electromagnetic radiation and crosstalk between the channels. The structure and operation principle of a quasi-distributed fiber-optic high-voltage monitoring system is presented. The sensitive element is a combination of a piezo-ceramic tube with an optical fiber wound around it. The device uses reverse transverse piezoelectric effect. The measurement principle is based on recording the change in the recirculation frequency under the applied voltage influence. When the measuring sections are arranged in ascending order of the measured effective voltages relative to the receiving-transmitting unit, a relative resolution of 0,3–0,45 % is achieved for the PZT-5H and 0,8–1,2 % for the PZT-4 in the voltage range 20–150 kV.

scholarly journals Sensing, Actuation, and Control of the SmartX Prototype Morphing Wing in the Wind Tunnel

Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 107
Author(s):  
Nakash Nazeer ◽  
Xuerui Wang ◽  
Roger M. Groves
Keyword(s):  
Wind Tunnel ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Experimental Testing ◽  
Single Mode ◽  
Fiber Optic Sensor ◽  
Sensor Data ◽  
Random Errors ◽  
Morphing Wing ◽  
Actuator Dynamics

This paper presents a study on trailing edge deflection estimation for the SmartX camber morphing wing demonstrator. This demonstrator integrates the technologies of smart sensing, smart actuation and smart controls using a six module distributed morphing concept. The morphing sequence is brought about by two actuators present at both ends of each of the morphing modules. The deflection estimation is carried out by interrogating optical fibers that are bonded on to the wing’s inner surface. A novel application is demonstrated using this method that utilizes the least amount of sensors for load monitoring purposes. The fiber optic sensor data is used to measure the deflections of the modules in the wind tunnel using a multi-modal fiber optic sensing approach and is compared to the deflections estimated by the actuators. Each module is probed by single-mode optical fibers that contain just four grating sensors and consider both bending and torsional deformations. The fiber optic method in this work combines the principles of hybrid interferometry and FBG spectral sensing. The analysis involves an initial calibration procedure outside the wind tunnel followed by experimental testing in the wind tunnel. This method is shown to experimentally achieve an accuracy of 2.8 mm deflection with an error of 9%. The error sources, including actuator dynamics, random errors, and nonlinear mechanical backlash, are identified and discussed.

Intrinsic High-Sensitivity Sensors Based on Etched Single-Mode Polymer Optical Fibers

2015 ◽  
Vol 27 (6) ◽  
pp. 604-607 ◽  
Author(s):  
Kishore Bhowmik ◽  
Gang-Ding Peng ◽  
Eliathamby Ambikairajah ◽  
Vedran Lovric ◽  
William R. Walsh ◽  
...  
Keyword(s):  
Optical Fibers ◽  
High Sensitivity ◽  
Single Mode ◽  
Polymer Optical Fibers

scholarly journals Analysis of Curvature in Fiber Optic Cable for Macrobending-Based Slope Sensor

2021 ◽  
Vol 3 (1) ◽  
pp. 45-56
Author(s):  
Imam Mulyanto
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Laser Intensity ◽  
Single Mode ◽  
Power Losses ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Working Principle

The analysis of fiber optics for macro bending-based slope sensors using SMF-28 single-mode optical fibers has been successfully conducted. Fiber optics were treated to silicon rubber molding and connected with laser light and power meters to measure the intensity of laser power generated. The working principle was carried out using the macrobending phenomenon on single-mode optical fibers. The intensity of laser light in fiber optic cables decreases in the event of indentation or bending of the fiber optic cable. Power losses resulting from the macrobending process can be seen in the result of the information sensitivity of fiber optics to the change of angle given. From the results of the study, the resulting fiber optic sensitivity value is -0.1534o/dBm. The larger the angle given, the lower the laser intensity received by the power meter.

scholarly journals Macrobending Loss Analysis on Singlemode-Multimode-Singlemode Fiber Optic Core

2019 ◽  
Vol 9 (2) ◽  
pp. 11-15
Author(s):  
Sisca Arisya Harry Andhina
Keyword(s):  
Light Source ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Optical Power ◽  
Single Mode ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Loss Analysis ◽  
Measurement Results ◽  
Source Test

Macrobending often occurs in optical fibers that embedded in the ground due to shifting of soil or rocks in the ground causing interference in transmission. In this study used single-mode-multimode-singlemode fiber optic cable connected manually and axially measured using a light source test equipment and optical power meter and the results will be compared. The measurement results obtained the greater  value of macrobending losses with the smaller the diameter of the winding, and the greater the number of turns. The highest value of macrobending losses in multimode cables is -1.48dB at 0.5cm diameter with 5 turns, highest value of macrobending losses on single mode cables is -12.73dB at 0.5cm diameter with 5 turns,  lowest value of macrobending losses for multimode cables is -0.44dB at 5cm diameter with 1 twist, lowest macrobending losses in singlemode cables is -1.69dB at 5cm diameter with 1 twist. While the value of macrobending losses on axially connected SMS cables shows the highest value of macrobending losses on multimode cables is -1.12dB in diameter of 0.5cm with 5 turns,  highest value of macrobending losses on singlemode cables is -1.18dB at diameter of 0.5cm with 5 turns,  lowest value for macrobending losses on multimode cables is -0.66dB at 5cm in diameter with 1 twist, the smallest value for macrobending losses on singlemode cables is -0.27dB at 5cm diameter with 1 twist . The measurement results also showed that the macrobending losses of manually connected SMS cables were greater than the macrobending losses of axially connected SMS cables.

Automated Fiber-Optic System for Monitoring the Stability of the Pit Quarry Mass and Dumps

2021 ◽  
pp. 19-26
Author(s):  
А.D. Меkhtiyev ◽  
◽  
E.G. Neshina ◽  
P.Sh. Madi ◽  
D.A. Gorokhov ◽  
...  
Keyword(s):  
Rock Mass ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Light Wave ◽  
Single Mode ◽  
Fiber Optic Sensors ◽  
Fiber Optic Sensor ◽  
Laboratory Sample ◽  
Single Mode Optical Fiber

This article ls with the issues related to the development of a system for monitoring the deformation and displacement of the rock mass leading to the collapse of the quarry sides. Monitoring system uses point-to-point fiber-optic sensors. Fiber-optic sensors and control cables of the communication line are made based on the single mode optical fibers, which allows to measure with high accuracy the deformations and displacements of the rock mass at a distance of 30-50 km. To create fiber-optic pressure sensors, an optical fiber of the ITU-T G. 652.D standard is used. Laboratory sample is developed concerning the point fiber-optic sensor made based on the two-arm Mach-Zender interferometer using a single mode optical fiber for monitoring strain (displacements) with a change in the sensitivity and a reduced influence of temperature interference leading to zero drift. The article presents a mathematical apparatus for calculating the intensity of radiation of a light wave passing through an optical fiber with and without mechanical stress. A laboratory sample of single mode optical fibers based on the Mach-Zender interferometer showed a fairly high linearity and accuracy in the measurement and can be used to control the strain of the mass after appropriate refinement of its design. Mathematical expressions are also given for determining the intensity of the light wave when the distance between the fixing points of a single mode optical fiber changes depending on the change in the external temperature. A diagram for measuring strain using a point fiber-optic strain sensor is developed. Hardware and software package is developed, which can be used to perform a number of settings of measuring channels. The work is aimed at solving the production problems of the Kenzhem quarry of AK Altynalmas JSC.

scholarly journals Curvature Analysis in Fiber Optic Cables as a Tilt Sensor Based on Macro Bending

2020 ◽  
Vol 2 (2) ◽  
pp. 91-99
Author(s):  
Imam Mulyanto
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Single Mode ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Curvature Analysis ◽  
Bending Process ◽  
Tilt Sensor

The test has been successfully carried out on optical fibers to be used as a macrobending tilt sensor using SMF-28 single mode optical fiber. The optical fiber was molded with silicon rubber, then connected to a laser light and a power meter to see the intensity of the laser power produced. The principle is carried out using the macro bending phenomenon on single mode optical fibers, where the laser light intensity in the fiber optic cable will decrease if there is a bend or bending in the fiber optic cable. We can observe the power loss resulting from the macro bending process to find out how sensitive the optical fiber is to changes in a given angle. The resulting optical fiber sensitivity value is -0.1534o/dBm.

scholarly journals A Bio-Compatible Fiber Optic pH Sensor Based on a Thin Core Interferometric Technique

Photonics ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 11 ◽  
Author(s):  
Magnus Engholm ◽  
Krister Hammarling ◽  
Henrik Andersson ◽  
Mats Sandberg ◽  
Hans-Erik Nilsson
Keyword(s):  
Fiber Optic ◽  
Ph Sensor ◽  
High Sensitivity ◽  
Single Mode ◽  
Measurement Range ◽  
Ph Sensitive ◽  
Fiber Optic Sensor ◽  
Design Parameters ◽  
Sensitive Material ◽  
Interferometric Technique

There is an increasing demand for compact, reliable and versatile sensor concepts for pH-level monitoring within several industrial, chemical as well as bio-medical applications. Many pH sensors concepts have been proposed, however, there is still a need for improved sensor solutions with respect to reliability, durability and miniaturization but also for multiparameter sensing. Here we present a conceptual verification, which includes theoretical simulations as well as experimental evaluation of a fiber optic pH-sensor based on a bio-compatible pH sensitive material not previously used in this context. The fiber optic sensor is based on a Mach-Zehnder interferometric technique, where the pH sensitive material is coated on a short, typically 20-25 mm thin core fiber spliced between two standard single mode fibers. The working principle of the sensor is simulated by using COMSOL Multiphysics. The simulations are used as a guideline for the construction of the sensors that have been experimentally evaluated in different liquids with pH ranging from 1.95 to 11.89. The results are promising, showing the potential for the development of bio-compatible fiber optic pH sensor with short response time, high sensitivity and broad measurement range. The developed sensor concept can find future use in many medical- or bio-chemical applications as well as in environmental monitoring of large areas. Challenges encountered during the sensor development due to variation in the design parameters are discussed.

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