1
|
Mou T, Zhu Y, Lin C, Zou C, Xie D, Zhu Y, Dang F, Yuan Y, Gao F, Yang J. Suppression of wavelength-dependent polarization fading using hybrid-polarization scheme in OFDR. Opt Express 2024; 32:1552-1561. [PMID: 38297704 DOI: 10.1364/oe.505132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/20/2023] [Indexed: 02/02/2024]
Abstract
What we believe to be a new hybrid-polarization diversity scheme which can eliminate the polarization state variation caused by wavelength tuning of laser in optical frequency domain reflectometry is proposed in the paper. In the scheme, a 45° polarizer is used to maintain the polarization of signals. It decreases the polarization angle fluctuation to 2.81° and realizes a -145 dB test sensitivity with a 32 dB Rayleigh scattering signal-to-noise ratio in a 10 m fiber single test. The polarization fading suppression is achieved for tests with a large wavelength tuning range from 1480 nm to 1640 nm. Meanwhile, a 6 µm spatial resolution is also achieved. The proposed scheme can be applied to the structure measurement of high-precision optical fiber devices with high spatial resolution and sensitivity.
Collapse
|
2
|
Wu Y, Gao L, Chai J, Li Z, Ma C, Qiu F, Yuan Q, Zhang D. Overview of Health-Monitoring Technology for Long-Distance Transportation Pipeline and Progress in DAS Technology Application. Sensors (Basel) 2024; 24:413. [PMID: 38257506 PMCID: PMC10818648 DOI: 10.3390/s24020413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 12/27/2023] [Accepted: 01/02/2024] [Indexed: 01/24/2024]
Abstract
There are various health issues associated with the different stages of long-distance pipeline transportation. These issues pose potential risks to environmental pollution, resource waste, and the safety of human life and property. It is essential to have real-time knowledge of the overall health status of pipelines throughout their entire lifecycle. This article investigates various health-monitoring technologies for long-distance pipelines, providing references for addressing potential safety issues that may arise during long-term transportation. This review summarizes the factors and characteristics that affect pipeline health from the perspective of pipeline structure health. It introduces the principles of major pipeline health-monitoring technologies and their respective advantages and disadvantages. The review also focuses on the application of Distributed Acoustic Sensing (DAS) technology, specifically time and space continuous monitoring technology, in the field of pipeline structure health monitoring. This paper discusses the process of commercialization development of DAS technology, the main research progress in the experimental field, and the open research issues. DAS technology has broad application prospects in the field of long-distance transportation pipeline health monitoring.
Collapse
Affiliation(s)
- Yuyi Wu
- China Coal Energy Research Institute Co., Ltd., Xi’an 710054, China;
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
- School of Mines, China University of Mining and Technology, Xuzhou 221116, China
| | - Lei Gao
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
| | - Jing Chai
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
| | - Zhi Li
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
| | - Chenyang Ma
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
| | - Fengqi Qiu
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
| | - Qiang Yuan
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
| | - Dingding Zhang
- College of Energy Engineering, Xi’an University of Science and Technology, Xi’an 710054, China; (L.G.); (J.C.); (C.M.); (F.Q.)
| |
Collapse
|
3
|
Li JC, Dong YX, Lei BJ, Xiao JL, Yang YD, Huang YZ. Optical time domain reflectometry based on a self-chaotic circular-sided microcavity laser. Appl Opt 2024; 63:154-158. [PMID: 38175016 DOI: 10.1364/ao.511255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 12/06/2023] [Indexed: 01/05/2024]
Abstract
A self-chaotic circular-sided square microcavity laser, with a chaos bandwidth of 12.9 GHz and a flatness of ±3d B, was applied in optical time domain reflectometry (OTDR). Using the broadband chaos laser, we demonstrated a range resolution of 4.5 mm and a 25-km detection distance experimentally. The solitary wide-bandwidth microcavity chaos laser, without the extra correlation peaks in optical feedback chaotic lasers, has shown potential advantages for correlation OTDR in practical application.
Collapse
|
4
|
Zhou X, Wang F, Yang C, Zhang Z, Zhang Y, Zhang X. Hybrid Distributed Optical Fiber Sensor for the Multi-Parameter Measurements. Sensors (Basel) 2023; 23:7116. [PMID: 37631654 PMCID: PMC10459902 DOI: 10.3390/s23167116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023]
Abstract
Distributed optical fiber sensors (DOFSs) are a promising technology for their unique advantage of long-distance distributed measurements in industrial applications. In recent years, modern industrial monitoring has called for comprehensive multi-parameter measurements to accurately identify fault events. The hybrid DOFS technology, which combines the Rayleigh, Brillouin, and Raman scattering mechanisms and integrates multiple DOFS systems in a single configuration, has attracted growing attention and has been developed rapidly. Compared to a single DOFS system, the multi-parameter measurements based on hybrid DOFS offer multidimensional valuable information to prevent misjudgments and false alarms. The highly integrated sensing structure enables more efficient and cost-effective monitoring in engineering. This review highlights the latest progress of the hybrid DOFS technology for multi-parameter measurements. The basic principles of the light-scattering-based DOFSs are initially introduced, and then the methods and sensing performances of various techniques are successively described. The challenges and prospects of the hybrid DOFS technology are discussed in the end, aiming to pave the way for a vaster range of applications.
Collapse
Affiliation(s)
- Xiao Zhou
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China; (X.Z.)
| | - Feng Wang
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China; (X.Z.)
| | - Chengyu Yang
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China; (X.Z.)
| | - Zijing Zhang
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China; (X.Z.)
| | - Yixin Zhang
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China; (X.Z.)
- Shenzhen Research Institute of Nanjing University, Shenzhen 518000, China
| | - Xuping Zhang
- Key Laboratory of Intelligent Optical Sensing and Manipulation, Ministry of Education, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China; (X.Z.)
- Shenzhen Research Institute of Nanjing University, Shenzhen 518000, China
| |
Collapse
|
5
|
Zheng W, Kou SS, Sheppard CJR, Roy M. Advancing full-field metrology: rapid 3D imaging with geometric phase ferroelectric liquid crystal technology in full-field optical coherence microscopy. Biomed Opt Express 2023; 14:3433-3445. [PMID: 37497495 PMCID: PMC10368045 DOI: 10.1364/boe.488806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 07/28/2023]
Abstract
Optical coherence microscopy (OCM) is a variant of OCT in which a high-numerical aperture lens is used. Full-field OCM (FF-OCM) is an emerging non-invasive, label-free, interferometric technique for imaging of surface structures or semi-transparent biomedical subjects with micron-scale resolutions. Different approaches to three dimensional full-field optical metrology are reviewed. The usual method for the phase-shifting technique in FF-OCM involves mechanically moving a mirror to change the optical path difference for obtaining en-face OCM images. However, with the use of a broadband source in FF-OCM, the phase shifts of different spectral components are not the same, resulting in the ambiguities in 3D image reconstruction. In this study, we demonstrate, by imaging tissues and cells, a unique geometric phase-shifter based on ferroelectric liquid crystal technology, to realize achromatic phase-shifting for rapid three-dimensional imaging in a FF-OCM system.
Collapse
Affiliation(s)
- Wei Zheng
- Department of Biomedical Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Shan S. Kou
- Chemistry and Physics, La Trobe University, Bundoora, Victoria 3083, Australia
| | - Colin J. R. Sheppard
- Nanoscopy and NIC@IIT, Istituto Italiano di Tecnologia, Via Enrico Melen, 83 Edificio B, 16152 Genova, Italy
- Molecular Horizons, School of Chemistry and Molecular Biosciences, University of Wollongong, Wollongong NSW 2522, Australia
| | - Maitreyee Roy
- School of Optometry and Vision Science, University of New South Wales, NSW 2052, Australia
| |
Collapse
|
6
|
Neves TFP, Scherino L, Bernard R, Bouet M, Pastre A, Magalhães R, Martin-Lopez S, Martins HF, Petagna P, Thévenaz L. Humidity-insensitive optical fibers for distributed sensing applications. Appl Opt 2023; 62:4017-4029. [PMID: 37706713 DOI: 10.1364/ao.487264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 04/21/2023] [Indexed: 09/15/2023]
Abstract
Humidity is a critical environmental factor in various applications, and its temperature dependence must be considered when developing thermo-hygrometer fiber sensors. The optical fibers that constitute the sensor must have a temperature reference, which should be resistant to humidity to avoid cross-sensitivities. This paper presents two innovative optical fibers insensitive to humidity over temperatures ranging from -20∘ C to 55°C. To the best of our knowledge, the novel standard size optical fibers coated with acrylate and silicone are tested under controlled conditions using an optical time-domain reflectometer sensor based on Rayleigh scattering. The sensor achieves meter-range resolution over kilometers of length with a response time of few minutes.
Collapse
|
7
|
Minardo A, Bernini R, Berruti GM, Breglio G, Bruno FA, Buontempo S, Campopiano S, Catalano E, Consales M, Coscetta A, Cusano A, Cutolo MA, Di Palma P, Esposito F, Fienga F, Giordano M, Iele A, Iadicicco A, Irace A, Janneh M, Laudati A, Leone M, Maresca L, Marrazzo VR, Pisco M, Quero G, Riccio M, Srivastava A, Vaiano P, Zeni L, Cutolo A. Innovative Photonic Sensors for Safety and Security, Part I: Fundamentals, Infrastructural and Ground Transportations. Sensors (Basel) 2023; 23:2558. [PMID: 36904762 PMCID: PMC10007142 DOI: 10.3390/s23052558] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/14/2023] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
Our group, involving researchers from different universities in Campania, Italy, has been working for the last twenty years in the field of photonic sensors for safety and security in healthcare, industrial and environment applications. This is the first in a series of three companion papers. In this paper, we introduce the main concepts of the technologies employed for the realization of our photonic sensors. Then, we review our main results concerning the innovative applications for infrastructural and transportation monitoring.
Collapse
Affiliation(s)
- Aldo Minardo
- Dipartimento di Ingegneria, Università della Campania Luigi Vanvitelli, Via Roma 29, 81031 Aversa, Italy
| | - Romeo Bernini
- Istituto per il Rilevamento Elettromagnetico dell’Ambiente, Consiglio Nazionale delle Ricerche, Via Diocleziano 328, 81024 Napoli, Italy
| | - Gaia Maria Berruti
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Giovanni Breglio
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Francesco Antonio Bruno
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Salvatore Buontempo
- National Institute for Nuclear Physics (INFN), 80125 Napoli, Italy
- European Organization for Nuclear Research (CERN), CH-1211 Geneva, Switzerland
| | - Stefania Campopiano
- Dipartimento di Ingegneria, Università degli Studi di Napoli Parthenope, Centro Direzionale Isola C4, 80143 Napoli, Italy
| | - Ester Catalano
- Dipartimento di Ingegneria, Università della Campania Luigi Vanvitelli, Via Roma 29, 81031 Aversa, Italy
- Optosensing Ltd., Via Carlo de Marco 69, 80137 Napoli, Italy
| | - Marco Consales
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Agnese Coscetta
- Dipartimento di Ingegneria, Università della Campania Luigi Vanvitelli, Via Roma 29, 81031 Aversa, Italy
| | - Andrea Cusano
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Maria Alessandra Cutolo
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Pasquale Di Palma
- Dipartimento di Ingegneria, Università degli Studi di Napoli Parthenope, Centro Direzionale Isola C4, 80143 Napoli, Italy
| | - Flavio Esposito
- Dipartimento di Ingegneria, Università degli Studi di Napoli Parthenope, Centro Direzionale Isola C4, 80143 Napoli, Italy
| | - Francesco Fienga
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Michele Giordano
- Istituto per i Polimeri, Compositi e Biomateriali Consiglio Nazionale delle Ricerche via Enrico Fermi 1, 80055 Portici, Italy
| | - Antonio Iele
- CERICT SCARL, CNOS Center, Viale Traiano, Palazzo ex Poste, 82100 Benevento, Italy
| | - Agostino Iadicicco
- Dipartimento di Ingegneria, Università degli Studi di Napoli Parthenope, Centro Direzionale Isola C4, 80143 Napoli, Italy
| | - Andrea Irace
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Mohammed Janneh
- CERICT SCARL, CNOS Center, Viale Traiano, Palazzo ex Poste, 82100 Benevento, Italy
| | | | - Marco Leone
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Luca Maresca
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Vincenzo Romano Marrazzo
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Marco Pisco
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Giuseppe Quero
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Michele Riccio
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| | - Anubhav Srivastava
- Dipartimento di Ingegneria, Università degli Studi di Napoli Parthenope, Centro Direzionale Isola C4, 80143 Napoli, Italy
| | - Patrizio Vaiano
- Dipartimento di Ingegneria, Università degli Studi del Sannio, Corso Garibaldi 107, Palazzo Bosco Lucarelli, 82100 Benevento, Italy
| | - Luigi Zeni
- Dipartimento di Ingegneria, Università della Campania Luigi Vanvitelli, Via Roma 29, 81031 Aversa, Italy
- Optosensing Ltd., Via Carlo de Marco 69, 80137 Napoli, Italy
| | - Antonello Cutolo
- Dipartimento di Ingegneria Elettrica e delle Tecnologie dell’Informazione, Università degli Studi di Napoli Federico II, Via Claudio 21, 80125 Napoli, Italy
| |
Collapse
|
8
|
Shang Y, Sun M, Wang C, Yang J, Du Y, Yi J, Zhao W, Wang Y, Zhao Y, Ni J. Research Progress in Distributed Acoustic Sensing Techniques. Sensors (Basel) 2022; 22:6060. [PMID: 36015819 PMCID: PMC9412507 DOI: 10.3390/s22166060] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/09/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Distributed acoustic sensing techniques based on Rayleigh scattering have been widely used in many applications due to their unique advantages, such as long-distance detection, high spatial resolution, and wide sensing bandwidth. In this paper, we provide a review of the recent advancements in distributed acoustic sensing techniques. The research progress and operation principles are systematically reviewed. The pivotal technologies and solutions applied to distributed acoustic sensing are introduced in terms of polarization fading, coherent fading, spatial resolution, frequency response, signal-to-noise ratio, and sensing distance. The applications of the distributed acoustic sensing are covered, including perimeter security, earthquake monitoring, energy exploration, underwater positioning, and railway monitoring. The potential developments of the distributed acoustic sensing techniques are also discussed.
Collapse
Affiliation(s)
- Ying Shang
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Maocheng Sun
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Chen Wang
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Jian Yang
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Yuankai Du
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Jichao Yi
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Wenan Zhao
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Yingying Wang
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| | - Yanjie Zhao
- College of Science, Shandong Jianzhu University, Jinan 250101, China
| | - Jiasheng Ni
- Laser Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250101, China
| |
Collapse
|
9
|
Shang Y, Wang C, Zhang Y, Zhao W, Ni J, Peng G. Non-Intrusive Pipeline Flow Detection Based on Distributed Fiber Turbulent Vibration Sensing. Sensors (Basel) 2022; 22:4044. [PMID: 35684664 DOI: 10.3390/s22114044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022]
Abstract
We demonstrate a non-intrusive dynamic monitoring method of oil well flow based on distributed optical fiber acoustic sensing (DAS) technology and the turbulent vibration. The quantitative measurement of the flow rate is theoretically acquired though the amplitude of the demodulated phase changes from DAS based on the flow impact in the tube on the pipe wall. The experimental results show that the relationships between the flow rate and the demodulated phase changes, in both a whole frequency region and in a sensitive-response frequency region, fit the quadratic equation well, with a max R2 of 0.997, which is consistent with the theoretical simulation results. The detectable flow rate is from 0.73 m3/h to 2.48 m3/h. The experiments verify the feasibility of DAS system flow monitoring and provide technical support for the practical application of the downhole flow measurement.
Collapse
|
10
|
Wu H, Du H, Zhao C, Tang M. 24 km High-Performance Raman Distributed Temperature Sensing Using Low Water Peak Fiber and Optimized Denoising Neural Network. Sensors 2022; 22:2139. [PMID: 35336310 PMCID: PMC8949466 DOI: 10.3390/s22062139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 11/17/2022]
Abstract
Raman distributed optical fiber temperature sensing (RDTS) has been extensively studied for decades because it enables accurate temperature measurements over long distances. The signal-to-noise ratio (SNR) is the main factor limiting the sensing distance and temperature accuracy of RDTS. We manufacture a low water peak optical fiber (LWPF) with low transmission loss to improve the SNR for long-distance application. Additionally, an optimized denoising neural network algorithm is developed to reduce noise and improve temperature accuracy. Finally, a maximum temperature uncertainty of 1.77 °C is achieved over a 24 km LWPF with a 1 m spatial resolution and a 1 s averaging time.
Collapse
|
11
|
Gasser J, Warpelin D, Bussières F, Extermann J, Pomarico E. Distributed temperature sensor combining centimeter resolution with hundreds of meters sensing range. Opt Express 2022; 30:6768-6777. [PMID: 35299455 DOI: 10.1364/oe.451699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
We present a Raman distributed temperature sensor based on standard telecom single mode fibers and efficient polarization-independent superconducting nanowire single photon detectors. Our device shows 3 cm and 1.5 °C resolution on a 5 m fiber upon one minute integration. We show that spatial resolution is limited by the laser pulse width and not by the detection system. Moreover, for long fibers the minimum distance for a measurable temperature step change increases of around 4 cm per km length, because of chromatic dispersion at the Stokes and Anti-Stokes wavelengths. Temperature resolution is mainly affected by the drop in the laser repetition rate when long fibers are tested. On a 500 m fiber, a trade-off of 10 cm and 8 °C resolution is achieved with 3 minutes integration. Fiber-based distributed temperature sensing, combining centimetric spatial resolution with hundreds of meters sensing range, could pave the way for a new kind of applications, such as 2D and 3D temperature mapping of complex electronic devices, particles detectors, cryogenic and aerospace instrumentation.
Collapse
|
12
|
Xue Y, Niu Y, Gong S. External Modulation Optical Coherent Domain Reflectometry with Long Measurement Range. Sensors (Basel) 2021; 21:s21165510. [PMID: 34450952 PMCID: PMC8401056 DOI: 10.3390/s21165510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/14/2021] [Accepted: 07/30/2021] [Indexed: 11/16/2022]
Abstract
Optical coherent domain reflectometry (OCDR) can achieve a high spatial resolution that is independent of the bandwidth of the receiver, but the measurement range is usually very limited. Here we propose an external modulation OCDR system, in which a pair of linear frequency-modulated pulses generated by one modulator are employed as the probe pulse and the reference, respectively. The spatial resolution is determined by the frequency modulation range of the pulse, and the measurement speed is boosted by orders because the proposed technology can simultaneously diagnose a section of fiber with each pair of pulses, while only a single point can be accessed at a time in typical OCDR. In the demonstrational experiment, a measurement range of up to 50 km is achieved with a spatial resolution of 1.4 m and a measuring time of less than 30 s.
Collapse
|
13
|
Vidovic I, Marschnig S. Optical Fibres for Condition Monitoring of Railway Infrastructure—Encouraging Data Source or Errant Effort? Applied Sciences 2020; 10:6016. [DOI: 10.3390/app10176016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The condition of railway infrastructure is currently assessed by track recording cars, wayside equipment, onboard monitoring techniques and visual inspections. These data sources deliver valuable information for infrastructure managers on the asset’s condition but are mostly carried out in time-based intervals. This paper examines the potential of fibre optic cables, which are already installed in cable troughs alongside railway tracks, to monitor railway infrastructure conditions. The sensing technique, known as distributed acoustic/vibration sensing (DAS/DVS), relies on the effect of Rayleigh scattering and transforms the optical fibre into an array of “virtual microphones” in the thousands. This sensing method has the ability to be used over long distances and thus provide information about the events taking place in the proximity of the monitored asset in real-time. This study outlines the potential of DAS for the identification of different track conditions and isolated track defects. The results are linked to asset data of the infrastructure manager to identify the root cause of the detected signal anomalies and pattern. A methodology such as this allows for condition-based and component-specific maintenance planning and execution and avoids the installation of additional sensors. DAS can pave the way toward a permanent and holistic assessment of railway tracks.
Collapse
|
14
|
Bednarska K, Sobotka P, Woliński TR, Zakręcka O, Pomianek W, Nocoń A, Lesiak P. Hybrid Fiber Optic Sensor Systems in Structural Health Monitoring in Aircraft Structures. Materials (Basel) 2020; 13:ma13102249. [PMID: 32414212 PMCID: PMC7288159 DOI: 10.3390/ma13102249] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/28/2020] [Accepted: 05/07/2020] [Indexed: 11/16/2022]
Abstract
‘Smart’ structural health monitoring of composite materials with optical fiber sensors is becoming more and more important, especially in the aviation industry. This paper presents an overview of hybrid fiber-optic sensing systems based on scattering techniques, fiber Bragg gratings, interferometric techniques, and polarimetric methods in structural health monitoring. The main purpose of this manuscript is to analyze the possibilities of using hybrid sensors based on fiber optics to monitor composite structures, with a particular emphasis on aircraft structures. Since it is difficult to indicate the most comprehensive approach due to different parameters of the described sensors, the review contains a detailed description of available solutions. We hope that this work will allow for a better and faster selection of the right solution for the problem at hand.
Collapse
Affiliation(s)
- Karolina Bednarska
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland; (K.B.); (P.S.); (T.R.W.)
| | - Piotr Sobotka
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland; (K.B.); (P.S.); (T.R.W.)
| | - Tomasz Ryszard Woliński
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland; (K.B.); (P.S.); (T.R.W.)
| | - Oliwia Zakręcka
- Polskie Zakłady Lotnicze Sp. z o.o., Wojska Polskiego 3, 39-300 Mielec, Poland; (O.Z.); (W.P.); (A.N.)
| | - Wiktor Pomianek
- Polskie Zakłady Lotnicze Sp. z o.o., Wojska Polskiego 3, 39-300 Mielec, Poland; (O.Z.); (W.P.); (A.N.)
| | - Agnieszka Nocoń
- Polskie Zakłady Lotnicze Sp. z o.o., Wojska Polskiego 3, 39-300 Mielec, Poland; (O.Z.); (W.P.); (A.N.)
| | - Piotr Lesiak
- Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warszawa, Poland; (K.B.); (P.S.); (T.R.W.)
- Correspondence:
| |
Collapse
|
15
|
Liu T, Sun W, Kou H, Yang Z, Meng Q, Zheng Y, Wang H, Yang X. Experimental Study of Leakage Monitoring of Diaphragm Walls Based on Distributed Optical Fiber Temperature Measurement Technology. Sensors (Basel) 2019; 19:s19102269. [PMID: 31100899 PMCID: PMC6567351 DOI: 10.3390/s19102269] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/29/2019] [Accepted: 05/14/2019] [Indexed: 12/03/2022]
Abstract
In geotechnical engineering seepage of diaphragm walls is an important issue which may cause engineering disasters. It is therefore of great significance to develop reliable monitoring technology to monitor the leakage. The purpose of this study is to explore the application of a distributed optical fiber temperature measurement system in leakage monitoring of underground diaphragm walls using 1 g model tests. The principles of seepage monitoring based on distributed optical fiber temperature measurement technology are introduced. Fiber with heating cable was laid along the wall to control seepage flow at different speeds. The temperature rise of the fiber during seepage was also recorded under different heating power conditions. In particular the effect of single variables (seepage velocity and heating power) on the temperature rise of optical fibers was discussed. Test results indicated that the temperature difference between the seepage and non-seepage parts of diaphragm wall can be monitored well using fiber-optic external heating cable. Higher heating power also can improve the resolution of fiber-optic seepage. The seepage velocity had a linear relationship with the final stable temperature after heating, and the linear correlation coefficient increases with the increase of heating power. The stable temperature decreased with the increase of flow velocity. The findings provide a basis for quantitative measurement and precise location of seepage velocity of diaphragm walls.
Collapse
Affiliation(s)
- Tao Liu
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Songling Road No. 238, Qingdao 266100, China.
- Pilot National Laboratory for Marine Science and Technology, Wenhai Road No.1, Qingdao 266003, China.
| | - Wenjing Sun
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Songling Road No. 238, Qingdao 266100, China.
| | - Hailei Kou
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Songling Road No. 238, Qingdao 266100, China.
- Pilot National Laboratory for Marine Science and Technology, Wenhai Road No.1, Qingdao 266003, China.
| | - Zhongnian Yang
- School of Civil Engineering, Qingdao University of Technology, Fushun Road No.11, Qingdao 266033, China.
| | - Qingsheng Meng
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Songling Road No. 238, Qingdao 266100, China.
- Pilot National Laboratory for Marine Science and Technology, Wenhai Road No.1, Qingdao 266003, China.
| | - Yuqian Zheng
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Songling Road No. 238, Qingdao 266100, China.
| | - Haotong Wang
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Songling Road No. 238, Qingdao 266100, China.
| | - Xiaotong Yang
- Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, Ocean University of China, Songling Road No. 238, Qingdao 266100, China.
| |
Collapse
|
16
|
Liu Y, Yin J, Tian Y, Fan X. Design and Performance Test of Transformer Winding Optical Fibre Composite Wire Based on Raman Scattering. Sensors (Basel) 2019; 19:s19092171. [PMID: 31083340 PMCID: PMC6539279 DOI: 10.3390/s19092171] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/25/2019] [Accepted: 05/08/2019] [Indexed: 11/16/2022]
Abstract
Winding overheating is a common fault in a transformer. To detect the temperature, the most widely used method is a point-type measurement, but traditional measurement methods cannot obtain the whole temperature distribution in a transformer. Taking this into consideration, a new method with which to measure the temperature of transformer windings was proposed. Based on Raman scattering, a new fibre-optic composite winding model was developed. The feasibility of the model was verified by electrical as well as temperature, field simulation and power frequency resistance testing. To assess the practicality and accuracy of the new model, a distributed optical fibre temperature measurement platform was built, and a series of experiments were designed. According to the data collected, the temperature measurement error based on the method could be limited to 1 °C while the positioning accuracy error was within 1 m, which meant that the new approach can satisfy the requirements of transformer winding temperature measurement and locate hot spots in the winding.
Collapse
Affiliation(s)
- Yunpeng Liu
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071003, China.
- Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defence, North China Electric Power University, Baoding 071003, China.
| | - Junyi Yin
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071003, China.
- Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defence, North China Electric Power University, Baoding 071003, China.
| | - Yuan Tian
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071003, China.
- Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defence, North China Electric Power University, Baoding 071003, China.
| | - Xiaozhou Fan
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071003, China.
- Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defence, North China Electric Power University, Baoding 071003, China.
| |
Collapse
|
17
|
Jousset P, Reinsch T, Ryberg T, Blanck H, Clarke A, Aghayev R, Hersir GP, Henninges J, Weber M, Krawczyk CM. Dynamic strain determination using fibre-optic cables allows imaging of seismological and structural features. Nat Commun 2018; 9:2509. [PMID: 29970883 PMCID: PMC6030137 DOI: 10.1038/s41467-018-04860-y] [Citation(s) in RCA: 241] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 05/21/2018] [Indexed: 11/21/2022] Open
Abstract
Natural hazard prediction and efficient crust exploration require dense seismic observations both in time and space. Seismological techniques provide ground-motion data, whose accuracy depends on sensor characteristics and spatial distribution. Here we demonstrate that dynamic strain determination is possible with conventional fibre-optic cables deployed for telecommunication. Extending recently distributed acoustic sensing (DAS) studies, we present high resolution spatially un-aliased broadband strain data. We recorded seismic signals from natural and man-made sources with 4-m spacing along a 15-km-long fibre-optic cable layout on Reykjanes Peninsula, SW-Iceland. We identify with unprecedented resolution structural features such as normal faults and volcanic dykes in the Reykjanes Oblique Rift, allowing us to infer new dynamic fault processes. Conventional seismometer recordings, acquired simultaneously, validate the spectral amplitude DAS response between 0.1 and 100 Hz bandwidth. We suggest that the networks of fibre-optic telecommunication lines worldwide could be used as seismometers opening a new window for Earth hazard assessment and exploration.
Collapse
Affiliation(s)
- Philippe Jousset
- GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany.
| | - Thomas Reinsch
- GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany.
| | - Trond Ryberg
- GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany
| | - Hanna Blanck
- ÍSOR Iceland GeoSurvey, Grensásvegi 9, Reykjavik, 108, Iceland
| | - Andy Clarke
- Silixa Ltd., Silixa House, 230 Centennial Park, Centennial Avenue, Elstree, WD6 3SN, UK
| | - Rufat Aghayev
- Silixa Ltd., Silixa House, 230 Centennial Park, Centennial Avenue, Elstree, WD6 3SN, UK
| | - Gylfi P Hersir
- ÍSOR Iceland GeoSurvey, Grensásvegi 9, Reykjavik, 108, Iceland
| | - Jan Henninges
- GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany
| | - Michael Weber
- GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany
- Institute of Earth and Environmental Science, University of Potsdam, Potsdam, 14476, Germany
| | - Charlotte M Krawczyk
- GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany
- Institute for Applied Geosciences, Technical University Berlin, Ernst-Reuter-Platz 1, Berlin, 10587, Germany
| |
Collapse
|
18
|
Younus MH, Ameen OF, Redzuan N, Ahmad N, Raja Ibrahim RK. Fabrication and characterization of multimode optical fiber sensor for chemical temperature monitoring using optical time domain reflectometer. Karbala International Journal of Modern Science 2018; 4:119-125. [DOI: 10.1016/j.kijoms.2017.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
19
|
Kenneth Hopkins F, Usechak NG, Kim H, Wang X, Trada H, Walsh KM. Photodiode array for characterizing optical fibers. Appl Opt 2018; 57:409-413. [PMID: 29400789 DOI: 10.1364/ao.57.000409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 12/11/2017] [Indexed: 06/07/2023]
Abstract
An innovative approach is proposed and demonstrated for measuring the attenuation of light in optical fibers. The technique utilizes a silicon device containing a v-groove that positions the fiber and detector array along the v-groove. The detectors within the v-groove are designed to partially surround the fiber in order to maximize the coupling of scattered light from the fiber into each detector.
Collapse
|
20
|
|
21
|
Ohno S, Iida D, Toge K, Manabe T. Long-range measurement of Rayleigh scatter signature beyond laser coherence length based on coherent optical frequency domain reflectometry. Opt Express 2016; 24:19651-19660. [PMID: 27557243 DOI: 10.1364/oe.24.019651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Long-range C-OFDR measurement of fiber Rayleigh scatter signature is described. The Rayleigh scatter signature, which is an interference pattern of backscatters from the random refractive indices in fibers, is known to be applicable to fiber identification and temperature or strain sensing by measuring its repeatability and its spectral shift. However, these applications have not been realized at ranges beyond the laser coherence length since laser phase noise degrades its repeatability. This paper proposes and demonstrates a method for analyzing the optical power spectrum of local Rayleigh backscatter to overcome the limitation imposed by laser phase noise. The measurable range and spatial performance are also investigated experimentally with respect to the remaining phase noise and noise reduction by signal averaging with the proposed method. The feasibility of Rayleigh scatter signature measurement for long-range applications is confirmed.
Collapse
|
22
|
Liu X, Jin B, Bai Q, Wang Y, Wang D, Wang Y. Distributed Fiber-Optic Sensors for Vibration Detection. Sensors (Basel) 2016; 16:s16081164. [PMID: 27472334 PMCID: PMC5017330 DOI: 10.3390/s16081164] [Citation(s) in RCA: 113] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/18/2016] [Accepted: 07/19/2016] [Indexed: 11/16/2022]
Abstract
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.
Collapse
Affiliation(s)
- Xin Liu
- Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No. 79 Yingzexi Street, Taiyuan 030024, China.
| | - Baoquan Jin
- Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No. 79 Yingzexi Street, Taiyuan 030024, China.
| | - Qing Bai
- Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No. 79 Yingzexi Street, Taiyuan 030024, China.
| | - Yu Wang
- Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No. 79 Yingzexi Street, Taiyuan 030024, China.
| | - Dong Wang
- Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No. 79 Yingzexi Street, Taiyuan 030024, China.
| | - Yuncai Wang
- Key Laboratory of Advanced Transducers and Intelligent Control Systems, Ministry of Education, Taiyuan University of Technology, No. 79 Yingzexi Street, Taiyuan 030024, China.
| |
Collapse
|
23
|
Shizuka M, Hayashi N, Mizuno Y, Nakamura K. Simplified optical correlation-domain reflectometry without reference path. Appl Opt 2016; 55:3925-3928. [PMID: 27411116 DOI: 10.1364/ao.55.003925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We develop a simplified configuration for optical correlation-domain reflectometry (OCDR) without an explicit reference path. Instead, the Fresnel-reflected light generated at the distal open end of the sensing fiber is exploited as a reference light. After the fundamental demonstration, the optimal incident power is found to be approximately 8 dBm. We also show that the loss near the distal end should not be applied, unlike in the case of Brillouin-based OCDR.
Collapse
|
24
|
Abstract
Extensive research on Brillouin- and Raman-based distributed optical fibre sensors over the past two decades has resulted in the commercialization of distributed sensors capable of measuring static and quasi-static phenomena such as temperature and strain. Recently, the focus has been shifted towards developing distributed sensors for measurement of dynamic phenomena such as dynamic strain and sound waves. This article reviews the current state of the art distributed optical fibre sensors capable of quantifying dynamic vibrations. The most important aspect of Rayleigh and Brillouin scattering processes which have been used for distributed dynamic measurement are studied. The principle of the sensing techniques used to measure dynamic perturbations are analyzed followed by a case study of the most recent advances in this field. It is shown that the Rayleigh-based sensors have longer sensing range and higher frequency range, but their spatial resolution is limited to 1 m. On the other hand, the Brillouin-based sensors have shown a higher spatial resolution, but relatively lower frequency and sensing ranges.
Collapse
Affiliation(s)
- Ali Masoudi
- Optoelectronics Research Centre, University of Southampton, Hampshire SO17 1BJ, United Kingdom
| | - Trevor P Newson
- Optoelectronics Research Centre, University of Southampton, Hampshire SO17 1BJ, United Kingdom
| |
Collapse
|
25
|
Abstract
There are many advantages to using direct frequency modulation for OFDR based DAS. However, achieving sufficiently linear scan via direct frequency modulation is challenging and poses limits on the scan parameters. A novel method for analyzing sinusoidal frequency modulated light is presented and demonstrated for both static and dynamic sensing. SFS-OFDR projects the measured signal onto appropriate sinusoidal phase terms to obtain spatial information. Thus, by using SFS-OFDR on sinusoidal modulated light it is possible to make use of the many advantages offered by direct frequency modulation without the limitations posed by the linearity requirement.
Collapse
|
26
|
Zhao Q, Xia L, Wan C, Hu J, Jia T, Gu M, Zhang L, Kang L, Chen J, Zhang X, Wu P. Long-haul and high-resolution optical time domain reflectometry using superconducting nanowire single-photon detectors. Sci Rep 2015; 5:10441. [PMID: 26020163 DOI: 10.1038/srep10441] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/13/2015] [Indexed: 11/29/2022] Open
Abstract
In classical optical time domain reflectometries (OTDRs), for sensing an 200-km-long fiber, the optical pulses launched are as wide as tens of microseconds to get enough signal-to-noise ratio, while it results in a two-point resolution of kilometers. To both reach long sensing distance and sub-kilometer resolution, we demonstrated a long-haul photon-counting OTDR using a superconducting nanowire single-photon detector. In a 40-minute-long measurement, we obtained a dynamic range of 46.9 dB, corresponding to a maximum sensing distance of 246.8 km, at a two-point resolution of 0.1 km. The time for measuring fiber after 100 km was reduced to one minute, while the fiber end at 217 km was still distinguished well from noise. After reducing the pulse width to 100 ns, the experimental two-point resolution was improved to 20 m while the maximum sensing distance was 209.47 km.
Collapse
|
27
|
Gabai H, Botsev Y, Hahami M, Eyal A. Optical frequency domain reflectometry at maximum update rate using I/Q detection. Opt Lett 2015; 40:1725-1728. [PMID: 25872058 DOI: 10.1364/ol.40.001725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We introduce a new optical frequency domain reflectometry (OFDR) system and processing method that utilize negative beat frequencies for the first time. The new approach enables efficient use of the available system bandwidth and facilitates distributed sensing with the maximum allowable update rate for a given fiber length. This is achieved by using a coherent optical-communications-type receiver that detects both the in-phase (I) and quadrature (Q) components of the backscatter field. The I and Q components are digitally combined to produce a complex backscatter signal whose Fourier transform is not necessarily symmetric. Judicious processing of the complex backscatter signal maps the reflection profile of one half of the sensing fiber to positive beat-frequencies and the profile of the other half to negative beat-frequencies. The new approach was tested via comprehensive computer simulations and experiment.
Collapse
|
28
|
Shiloh L, Eyal A. Distributed acoustic and vibration sensing via optical fractional Fourier transform reflectometry. Opt Express 2015; 23:4296-4306. [PMID: 25836466 DOI: 10.1364/oe.23.004296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Distributed acoustic sensing has been traditionally implemented using optical reflectometry. Here we describe an alternative to the common interrogation approaches. According to the new method the frequency of the source is varied sinusoidally with time. For a sufficiently high scan frequency there is a position along the fiber, z(0), for which the roundtrip time is half the scan period. Back-reflections from this point will generate a linear chirp at the receiver output. The Fractional Fourier Transform (FrFT) is used to analyze the receiver output and yields the reflection profile at z(0) and its vicinity. The method, which enables high spatial resolution at long distances with high scan rates, is demonstrated by detecting deliberate perturbations in the Rayleigh backscatter profile at the end of a 20km fiber with a scanning frequency of ~2.5kHz. The spatial resolution at this range and scan-rate is characterized by a measurement of the backscatter profile from a FBG's-array and is found to be ~2.8m.
Collapse
|
29
|
Zhu N, Tong Y, Chen W, Wang S, Sun W, Liu J. Improved wavelength coded optical time domain reflectometry based on the optical switch. Opt Express 2014; 22:15111-15117. [PMID: 24977604 DOI: 10.1364/oe.22.015111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This paper presents an improved wavelength coded time-domain reflectometry based on the 2 × 1 optical switch. In this scheme, in order to improve the signal-noise-ratio (SNR) of the beat signal, the improved system used an optical switch to obtain wavelength-stable, low-noise and narrow optical pulses for probe and reference. Experiments were set up to demonstrate a spatial resolution of 2.5m within a range of 70km and obtain the beat signal with line width narrower than 15 MHz within a range of 50 km in fiber break detection. A system for wavelength-division-multiplexing passive optical network (WDM-PON) monitoring was also constructed to detect the fiber break of different channels by tuning the current applied on the gating section of the distributed Bragg reflector (DBR) laser.
Collapse
|
30
|
Shentu GL, Sun QC, Jiang X, Wang XD, Pelc JS, Fejer MM, Zhang Q, Pan JW. 217 km long distance photon-counting optical time-domain reflectometry based on ultra-low noise up-conversion single photon detector. Opt Express 2013; 21:24674-24679. [PMID: 24150311 DOI: 10.1364/oe.21.024674] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We demonstrate a photon-counting optical time-domain reflectometry with 42.19 dB dynamic range using an ultra-low noise up-conversion single photon detector. By employing the long-wave pump technique and a volume Bragg grating, we achieve a noise equivalent power of -139.7 dBm/√Hz for our detector. We perform the OTDR experiments using a fiber of length approximate 217 km, and show that our system can identify defects along the entire fiber length in a measurement time of 13 minutes.
Collapse
|
31
|
Eich S, Schmälzlin E, Löhmannsröben HG. Distributed fiber optical sensing of oxygen with optical time domain reflectometry. Sensors (Basel) 2013; 13:7170-83. [PMID: 23727953 PMCID: PMC3715240 DOI: 10.3390/s130607170] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/28/2013] [Indexed: 11/22/2022]
Abstract
In many biological and environmental applications spatially resolved sensing of molecular oxygen is desirable. A powerful tool for distributed measurements is optical time domain reflectometry (OTDR) which is often used in the field of telecommunications. We combine this technique with a novel optical oxygen sensor dye, triangular-[4] phenylene (TP), immobilized in a polymer matrix. The TP luminescence decay time is 86 ns. The short decay time of the sensor dye is suitable to achieve a spatial resolution of some meters. In this paper we present the development and characterization of a reflectometer in the UV range of the electromagnetic spectrum as well as optical oxygen sensing with different fiber arrangements.
Collapse
Affiliation(s)
- Susanne Eich
- Institute of Chemistry/Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, Potsdam-Golm 14476,
Germany; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +49-0331-977-5238; Fax: +49-0331-977-5058
| | - Elmar Schmälzlin
- Colibri Photonics GmbH, Am Mühlenberg 11, Potsdam-Golm 14476,
Germany; E-Mail:
| | - Hans-Gerd Löhmannsröben
- Institute of Chemistry/Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, Potsdam-Golm 14476,
Germany; E-Mail:
| |
Collapse
|
32
|
Ding Z, Yao XS, Liu T, Du Y, Liu K, Han Q, Meng Z, Chen H. Long-range vibration sensor based on correlation analysis of optical frequency-domain reflectometry signals. Opt Express 2012; 20:28319-28329. [PMID: 23263066 DOI: 10.1364/oe.20.028319] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a novel method to achieve a space-resolved long- range vibration detection system based on the correlation analysis of the optical frequency-domain reflectometry (OFDR) signals. By performing two separate measurements of the vibrated and non-vibrated states on a test fiber, the vibration frequency and position of a vibration event can be obtained by analyzing the cross-correlation between beat signals of the vibrated and non-vibrated states in a spatial domain, where the beat signals are generated from interferences between local Rayleigh backscattering signals of the test fiber and local light oscillator. Using the proposed technique, we constructed a standard single-mode fiber based vibration sensor that can have a dynamic range of 12 km and a measurable vibration frequency up to 2 kHz with a spatial resolution of 5 m. Moreover, preliminarily investigation results of two vibration events located at different positions along the test fiber are also reported.
Collapse
Affiliation(s)
- Zhenyang Ding
- College of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072, China
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
The spatial resolution of OFDR is normally degraded by the laser phase noise, deviations from linear frequency scan and acoustic noise in the fibers. A method for mitigating these degradation mechanisms, without using an auxiliary interferometer, via inline auxiliary points, is presented and demonstrated experimentally. Auxiliary points are points that are a priori known to have (spatial) impulse reflectivities. Their responses are used for compensating the phase deviations that degrade the response of points that are further away from the source.
Collapse
Affiliation(s)
- Oren Y Sagiv
- School of Electrical Engineering, Faculty of Engineering, Tel-Aviv University, Ramat Aviv, Tel-Aviv, 69978, Israel.
| | | | | |
Collapse
|
34
|
Fan X, Koshikiya Y, Ito F. Centimeter-level spatial resolution over 40 km realized by bandwidth-division phase-noise-compensated OFDR. Opt Express 2011; 19:19122-19128. [PMID: 21996853 DOI: 10.1364/oe.19.019122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present a bandwidth-division phase-noise-compensated optical frequency domain reflectometry (PNC-OFDR) technique, which permits a fast sweep of the optical source frequency. This method makes it possible to reduce the influence of environmental perturbation, which is the dominant factor degrading the spatial resolution of frequency-domain reflectometry at a long measurement range after compensation of the optical source phase noise. By using this approach, we realize a sub-cm spatial resolution over 40 km in a normal laboratory environment, and a 5 cm spatial resolution at 39.2 km in a field trial.
Collapse
Affiliation(s)
- Xinyu Fan
- NTT Access Network Service Systems Laboratories, NTT Corporation, 1-7-1 Hanabatake, Tsukuba, Ibaraki 305-0805, Japan.
| | | | | |
Collapse
|
35
|
Sorin F, Lestoquoy G, Danto S, Joannopoulos JD, Fink Y. Resolving optical illumination distributions along an axially symmetric photodetecting fiber. Opt Express 2010; 18:24264-24275. [PMID: 21164772 DOI: 10.1364/oe.18.024264] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Photodetecting fibers of arbitrary length with internal metal, semiconductor and insulator domains have recently been demonstrated. These semiconductor devices exhibit a continuous translational symmetry which presents challenges to the extraction of spatially resolved information. Here, we overcome this seemingly fundamental limitation and achieve the detection and spatial localization of a single incident optical beam at sub-centimeter resolution, along a one-meter fiber section. Using an approach that breaks the axial symmetry through the constuction of a convex electrical potential along the fiber axis, we demonstrate the full reconstruction of an arbitrary rectangular optical wave profile. Finally, the localization of up to three points of illumination simultaneously incident on a photodetecting fiber is achieved.
Collapse
Affiliation(s)
- Fabien Sorin
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge MA 02139, USA
| | | | | | | | | |
Collapse
|
36
|
Takeuchi A, Miwa T, Shirataka M, Sawada M, Imaizumi H, Sugibuchi H, Ikeda N. Non-cladding optical fiber is available for detecting blood or liquids. J Clin Monit Comput 2010; 24:363-70. [PMID: 20697933 DOI: 10.1007/s10877-010-9255-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 07/29/2010] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Serious accidents during hemodialysis such as an undetected large amount of blood loss are often caused by venous needle dislodgement. A special plastic optical fiber with a low refractive index was developed for monitoring leakage in oil pipelines and in other industrial fields. To apply optical fiber as a bleeding sensor, we studied optical effects of soaking the fiber with liquids and blood in light-loss experimental settings. METHODS The non-cladding optical fiber that was used was the fluoropolymer, PFA fiber, JUNFLON™, 1 mm in diameter and 2 m in length. Light intensity was studied with an ordinary basic circuit with a light emitting source (880 nm) and photodiode set at both terminals of the fiber under certain conditions: bending the fiber, soaking with various mediums, or fixing the fiber with surgical tape. The soaking mediums were reverse osmosis (RO) water, physiological saline, glucose, porcine plasma, and porcine blood. The light intensities regressed to a decaying exponential function with the soaked length. RESULTS The light intensity was not decreased at bending from 20 to 1 cm in diameter. The more the soaked length increased in all mediums, the more the light intensity decreased exponentially. The means of five estimated exponential decay constants were 0.050±0.006 standard deviation in RO water, 0.485±0.016 in physiological saline, 0.404±0.022 in 5% glucose, 0.503±0.038 in blood (Hct 40%), and 0.573±0.067 in plasma. The light intensity decreased from 5 V to about 1.5 V above 5 cm in the soaked length in mediums except for RO water and fixing with surgical tape. CONCLUSIONS We confirmed that light intensity significantly and exponentially decreased with the increased length of the soaked fiber. This phenomena could ideally, clinically be applied to a bleed sensor.
Collapse
Affiliation(s)
- Akihiro Takeuchi
- Department of Medical Informatics, School of Allied Health Sciences, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan.
| | | | | | | | | | | | | |
Collapse
|
37
|
Measor P, Kühn S, Lunt EJ, Phillips BS, Hawkins AR, Schmidt H. Hollow-core waveguide characterization by optically induced particle transport. Opt Lett 2008; 33:672-4. [PMID: 18382513 PMCID: PMC2864579 DOI: 10.1364/ol.33.000672] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We introduce a method for optical characterization of hollow-core optical waveguides. Radiation pressure exerted by the waveguide modes on dielectric microspheres is used to analyze salient properties such as propagation loss and waveguide mode profiles. These quantities were measured for quasi-single-mode and multimode propagation in on-chip liquid-filled hollow-core antiresonant reflecting optical waveguides. Excellent agreement with analytical and numerical models is found, demonstrating that optically induced particle transport provides a simple, inexpensive, and nondestructive alternative to other characterization methods.
Collapse
Affiliation(s)
- Philip Measor
- School of Engineering, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
| | | | | | | | | | | |
Collapse
|
38
|
Möckel H, Grunert R, Pössneck A, Hofer M, Thalheim M, Strauss G, Fickweiler U, Meixensberger J, Dietz A, Korb W. [ElePhant: an anatomic-electronic simulation system for the evaluation of computer assisted interventions and surgical education]. BIOMED ENG-BIOMED TE 2007; 52:375-82. [PMID: 18047402 DOI: 10.1515/bmt.2007.062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Suitable simulation systems providing realistic conditions are required for preclinical evaluation of computer assisted interventions and surgical training. Techniques are necessary for an objective detection of injuries to the structures at risk. The aim of this study was the technical realization of a simulation system for the ENT intervention, mastoidectomy. MATERIALS AND METHODS The basis of the simulation system was a CT scan of a cadaver skull. Using 3D printing, an anatomical phantom with realistic bone-like properties was created. Electronic detection systems were integrated into the structures at risk. A study with 16 ENT surgeons was conducted to prove the system's suitability for surgical training. RESULTS The creation of simulation systems for the objective evaluation of surgical intervention qualities is feasible. A modular structure enables economic and simple replacement of the simulation area. The modules are cost effective and reproducible with high accuracy. The present study shows that the simulation system can be applied in surgical education and evaluation as an alternative to cadavers. CONCLUSION Objective evaluation of injured structures at risk can be realized in real time. The simulation system permits preclinical evaluation studies of computer assisted instruments and surgical education. Reproducibility of the results makes multi-center studies possible.
Collapse
Affiliation(s)
- Hendrik Möckel
- Innovation Center Computer Assisted Surgery (ICCAS), Universität Leipzig, Leipzig, Deutschland.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
Field tests in desert terrain of a distributed sensor system for detecting and locating intruders based on the phase-sensitive optical-time-domain reflectometer (phi-OTDR) are described. The sensing element is a single-mode telecommunications fiber in a 4.5 mm diameter cable buried in a trench filled with loose sand. Light pulses from a continuous-wave Er:fiber Fabry-Perot laser with a narrow (<3 kHz) instantaneous linewidth and low (few kilohertz per second) frequency drift are injected into one end of the fiber, and the orthogonal polarizations of the backscattered light are monitored with separate receivers. Localized phase changes in the optical carrier are sensed by subtracting a phi-OTDR trace from an earlier stored trace. High sensitivity and consistent detection of intruders on foot and of vehicles traveling down a road near the cable line was realized over a cable length of 8.5 km and a total fiber path of 19 km in real time.
Collapse
Affiliation(s)
- Juan C Juarez
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723-6099, USA.
| | | |
Collapse
|
40
|
Juarez JC, Taylor HF. Polarization discrimination in a phase-sensitive optical time-domain reflectometer intrusion-sensor system. Opt Lett 2005; 30:3284-6. [PMID: 16389806 DOI: 10.1364/ol.30.003284] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
A distributed sensor system for detecting and locating intruders based on a phase-sensitive optical time-domain reflectometer (phi-OTDR) that utilizes polarization discrimination is described. The sensing element is a single-mode telecommunications fiber in a 3 mm diameter cable buried along a monitored perimeter in a 20-46 cm deep, 10 cm wide trench in clay soil. Light pulses from a continuous-wave Er fiber Fabry-Perot laser with a narrow (< 3 kHz) instantaneous linewidth and low (a few Kilohertz per second) frequency drift are injected into one end of the fiber, and the orthogonal polarizations of the backscattered light are monitored with separate receivers. Localized phase changes in the optical carrier are sensed by subtraction of a phi-OTDR trace from an earlier stored trace. In field tests with a monitored length of 12 km, detection of intruders on foot as far as 4.5 m from the cable line was consistently achieved.
Collapse
Affiliation(s)
- Juan C Juarez
- Department of Electrical Engineering, 214 ZEC, 3128 Texas A&M University, College Station, Texas 77843-3128, USA.
| | | |
Collapse
|
41
|
Abstract
A distributed sensing system for apolar hydrocarbons is presented which is built from a polymer-clad silica fiber adapted to an optical time domain reflectometer (OTDR) set-up. OTDR measurements allow locating and detecting chemicals by measuring the time delay between short light pulses entering the fiber and discrete changes in the backscatter signals that are caused by local extraction of hydrocarbons into the fiber cladding. The light guiding properties of the fiber are affected by interaction of the extracted chemicals with the evanescent wave light field extending into the fiber cladding. Distributed sensing of pure liquid hydrocarbons (HC) and aqueous HC solutions with a commercially available mini-OTDR adapted to sensing fibers of up to 1km length could be demonstrated. A pulsed laser diode emitting at the 850 nm telecommunication wavelength was applied in the mini-OTDR to locate the HCs by analyzing the step drop (light loss) in the backscatter signal, which is induced by local refractive index (RI) increase in the silicone cladding due to the extracted HC. The prototype instrument can be applied for monitoring hydrocarbon leakage in large technical installations, such as tanks, chemical pipelines or chemical waste disposal containments.
Collapse
Affiliation(s)
- J Buerck
- Forschungszentrum Karlsruhe, Institut für Instrumentelle Analytik-IFIA, PO Box 3640, D-76021 Karlsruhe, Germany.
| | | | | | | |
Collapse
|
42
|
King D, Lyons WB, Flanagan C, Lewis E. An optical fibre ethanol concentration sensor utilizing Fourier transform signal processing analysis and artificial neural network pattern recognition. ACTA ACUST UNITED AC 2003. [DOI: 10.1088/1464-4258/5/4/357] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
43
|
Lyons WB, Ewald H, Flanagan C, Lewis E. An optical fibre sensor for in situ measurement of external species in fluids based on artificial neural network pattern recognition. Physiol Meas 2001; 22:635-46. [PMID: 11556681 DOI: 10.1088/0967-3334/22/3/319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An optical fibre sensor system capable of detecting contaminants (e.g. particles, inorganic or organic species) in water and other fluids is reported. In this article experimental results are presented for a single optical fibre sensor located at a distance of 150 m from the transmitter/receiver of the system. The fibre is addressed using an optical time domain reflectometer (OTDR) in order to achieve the spatial resolution (along the fibre length) necessary for this investigation. Novel signal processing techniques involving artificial neural networks and pattern recognition have been applied to the signals arising from the sensor in order to allow cross-sensitivity effects, e.g. from fouling due to calcification, to be extracted from the real measurand, e.g. alcohol content.
Collapse
Affiliation(s)
- W B Lyons
- Department of Electronics and Computer Engineering, University of Limerick, Ireland.
| | | | | | | |
Collapse
|
44
|
Shimotahira H, Iizuka K, Chu SC, Wah C, Costen F, Yoshikuni Y. Three-dimensional laser microvision. Appl Opt 2001; 40:1784-1794. [PMID: 18357177 DOI: 10.1364/ao.40.001784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 mum; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 mum.
Collapse
|
45
|
Naruse H, Tateda M. Launched pulse-shape dependence of the power spectrum of the spontaneous brillouin backscattered light in an optical fiber. Appl Opt 2000; 39:6376-6384. [PMID: 18354650 DOI: 10.1364/ao.39.006376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We theoretically analyze the relationship between the electric field envelope shape of an optical pulse launched into an optical fiber and the power spectrum of the spontaneous Brillouin backscattered light it produces. The electric field envelope is characterized by the pulse width, leading-trailing time, and steepness. The peak power of the launched, pulsed-light power spectrum is proportional to the square of the pulse width regardless of the pulse leading-trailing time and steepness, and the power spectrum broadens in inverse proportion to the pulse width. The peak power of the spontaneous Brillouin backscattered light produced by the launched, pulsed light is proportional to the pulse width when it is above approximately 100 ns and is proportional to the square of the pulse width when it is below approximately 1 ns. The power spectrum of the spontaneous Brillouin backscattered light also broadens rapidly corresponding to the pulse width, when the pulse width falls below approximately 30 ns. As the pulse leading-trailing time is shortened or the pulse leading-trailing part becomes steep, the Brillouin backscattered-light power spectrum broadens greatly, even if the launched pulse width remains constant. Our analysis showed that an optical pulse with a triangular-shaped electric field envelope forms the Brillouin backscattered-light power spectrum with the narrowest profile and consequently gives the minimum error in measuring the peak-power frequency, when the pulse width is below approximately 50 ns. The measurement error with the triangular-shaped pulsed light is 1/square root(2) times smaller than that for a rectangular-shaped pulsed light, when the pulse width falls below several nanoseconds. By contrast, the rectangular-shaped envelope gives the minimum error when the pulse width exceeds approximately 50 ns.
Collapse
Affiliation(s)
- H Naruse
- Access Network Service Systems Laboratories, NTT, 1-7-1, Hanabatake, Tsukuba, Ibaraki 305-0805 Japan.
| | | |
Collapse
|
46
|
|
47
|
|
48
|
Naruse H, Tateda M. Trade-off between the spatial and the frequency resolutions in measuring the power spectrum of the Brillouin backscattered light in an optical fiber. Appl Opt 1999; 38:6516-6521. [PMID: 18324183 DOI: 10.1364/ao.38.006516] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We theoretically analyze the relation between the pulse width of light launched into an optical fiber and the resultant power spectrum of spontaneous Brillouin backscattered light. Through this analysis, we determine numerically that the bandwidth of the Brillouin backscattered light becomes wider, and thus the measurement accuracy in determining the peak-power frequency degrades in approximately inverse proportion to the launched pulse width. Experimental results with various pulse widths are in good agreement with the derived theoretical results.
Collapse
Affiliation(s)
- H Naruse
- Access Network Service Systems Laboratory, NTT, 1-7-1 Hanabatake, Tsukuba, Ibaraki 305-0805, Japan.
| | | |
Collapse
|
49
|
Masters BR. Early development of optical low-coherence reflectometry and some recent biomedical applications. J Biomed Opt 1999; 4:236-247. [PMID: 23015210 DOI: 10.1117/1.429914] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This paper explains the term low-coherence interferometry, reviews the early development of optical low-coherence reflectometry, and shows some of the paths that led to the field of biomedical optics. This paper demonstrates that early technical developments in the telecommunications industry resulted in a myriad of technical implementations and applications in biology, medicine, and the explosion of the field in noninvasive biomedical optical techniques. Recent examples of innovative applications of this proliferating technology into the fields of ophthalmology, developmental biology, and endoscopy are described. © 1999 Society of Photo-Optical Instrumentation Engineers.
Collapse
|
50
|
Garus D, Krebber K, Schliep F, Gogolla T. Distributed sensing technique based on Brillouin optical-fiber frequency-domain analysis. Opt Lett 1996; 21:1402-1404. [PMID: 19876366 DOI: 10.1364/ol.21.001402] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A new sensing technique for the distributed measurement of temperature and strain, based on Brillouin optical frequency-domain analysis, is presented. Theoretical investigations and first experimental results of distributed measurements demonstrate the feasibility of this new concept.
Collapse
|