Review
Engineering, Multidisciplinary
Ruonan Ou, Linqing Luo, Kenichi Soga
Summary: This paper introduces a crack analysis method based on decomposing the Brillouin scattering spectrum to overcome the spatial resolution limitation of traditional methods, thus improving the ability to measure the highly localized strain generated by sub-millimeter cracks.
STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL
(2023)
Article
Optics
Shuangxiang Zhao, Qingwen Liu, Jiageng Chen, Zuyuan He
Summary: In the field of fiber-optic sensors (FOSs), significant efforts have been made in the past decade to challenge the thermal-noise-level sensing resolution for passive FOS. Although some claims have been made regarding achieving thermal-noise-level resolution, the realization of this resolution for passive FOSs remains controversial and challenging. This paper presents an ultrahigh-resolution FOS system with a sensing resolution surpassing existing high-resolution passive FOSs, utilizing a fiber Fabry-Perot interferometer as the sensing element and the Pound-Drever-Hall technique to interrogate it with an ultra-stable probe laser. Strain and temperature measurements are conducted to validate the sensor's performance, with the measured noise floor aligning well with the theoretical thermal noise level.
Article
Engineering, Electrical & Electronic
Wookjin Jeong, Gyu-Tae Kim, Kwang Yong Song, Sang Bae Lee, Kwanil Lee
Summary: We propose and experimentally demonstrate a long-range Brillouin optical correlation domain analysis (BOCDA) system based on distributed Raman amplification and injection-locking, achieving over 2.6 million resolving points. By optimizing key parameters in the Raman amplification, time domain data processing, differential measurement scheme, and injection-locking, a spatial resolution of 2 cm over a 50 km sensing fiber is achieved. Our result shows at least twice improvement compared to previous records and achieves the highest number of resolving points among distributed Brillouin sensors.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Alaaeddine Rjeb, Amr M. Ragheb, Maged A. Esmail, Habib Fathallah, Saleh A. Alshebeili
Summary: In this study, a novel ring core fiber structure was proposed and numerically investigated for simultaneous temperature and strain measurements. The results showed that the fiber achieved high gain and low measurement errors, indicating its potential for practical applications.
Article
Engineering, Electrical & Electronic
Zonglei Li, Yin Zhou, Zexi Hua, Lianshan Yan
Summary: Phase-based measurement can perfectly avoid the problem of relative intensity noise transfer by showing that RIN only affects the amplitude of the Brillouin probe and not its phase. This phase-based measurement reduces the measurement uncertainty by about 5 times, through a 2.5 times reduction in uncertainty compared to gain-based measurement and an additional 2 times reduction through the designed phase-noise-insensitive coherent detection scheme.
IEEE SENSORS JOURNAL
(2023)
Review
Chemistry, Analytical
Christos Karapanagiotis, Katerina Krebber
Summary: This paper presents machine learning approaches applied in the field of Brillouin distributed fiber optic sensors (DFOSs). Brillouin DFOSs have gained popularity due to their ability to continuously monitor temperature and strain along kilometer-long optical fibers, making them attractive for industrial applications. Machine learning has been integrated into Brillouin DFOS signal processing, resulting in enhanced measurements without increasing the system's cost. This paper provides an overview of the applied machine learning methodologies in Brillouin DFOSs and discusses future perspectives in this area.
Article
Engineering, Multidisciplinary
Tianran Han, Gang Wu, Yong Lu
Summary: This study introduces a novel fiber-optic sensor for early crack detection and accurate crack width measurement, verified through numerical simulations and controlled laboratory tests. The peak-fitting-based methodology is adopted for analyzing data to achieve accurate crack monitoring. The proposed sensor may facilitate economical long-distance distributed crack sensing for various infrastructures.
Article
Engineering, Electrical & Electronic
Bohong Zhang, Hanok Tekle, Ronald J. O'Malley, Jeffrey D. Smith, Rex E. Gerald, Jie Huang
Summary: This study presents the first in situ high-temperature fiber-optic Raman probe capable of studying the structure of glass and slag samples at temperatures up to 1400 degrees C. By integrating a customized external telescope into a portable fiber-optic Raman probe, the optical working distance was extended to enable high-temperature operation. The probe successfully collected and analyzed Raman spectra at both room temperature and high temperatures, and a deconvolution algorithm was used to identify molecular structure components. This method holds great potential for applications in materials development, composition and structure monitoring, chemical identification, and process monitoring in industrial production.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Engineering, Electrical & Electronic
Marianne Stely Peixoto e Silva, Thales Henrique Castro de Barros, Henrique Patriota Alves, Jehan Fonseca do Nascimento, Joaquim Ferreira Martins Filho
Summary: Distributed fiber optic temperature sensor based on spontaneous Raman scattering is experimental evaluated over a wide range of temperatures, providing accurate values and fine resolution in temperature measurement.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Civil
Ruba A. M. Mohamed, Chris Gabrielli, John S. Selker, Frank Selker, Scott C. Brooks, Tanzila Ahmed, Kenneth C. Carroll
Summary: Measuring surface water temperature spatial variability is crucial for various purposes. FO-DTS is effective but challenging in certain stream conditions. Comparing FO-DTS with the towed transect method in East Fork Poplar Creek showed strong correlation, with differences near stream banks attributed to shallower water and lower data density. Individual temperature sensors can be a practical alternative to FO-DTS, offering slightly lower resolution but higher accuracy and simplicity.
JOURNAL OF HYDROLOGY
(2021)
Review
Chemistry, Analytical
Xiao Zhou, Feng Wang, Chengyu Yang, Zijing Zhang, Yixin Zhang, Xuping Zhang
Summary: Distributed optical fiber sensors (DOFSs) are a promising technology for long-distance distributed measurements in industrial applications. The hybrid DOFS technology, which combines multiple DOFS systems in a single configuration, has attracted growing attention and has been rapidly developed. It offers multi-parameter measurements based on the Rayleigh, Brillouin, and Raman scattering mechanisms, providing valuable information to prevent misjudgments and false alarms.
Article
Optics
Nageswara Lalam, Hari Bhatta, Xiaoguang Sun, Ping Lu, Paul Ohodnicki, Michael p. Buric, Ruishu Wright
Summary: This paper presents a multi-parameter fiber sensing system based on a double-Brillouin peak specialty fiber with enhanced Brillouin gain response. Compared to other multi-Brillouin peak fibers, the proposed fiber significantly reduces measurement errors and improves strain and temperature accuracy. Successful discriminative measurement of strain and temperature is achieved by utilizing the sensitivity values of each Brillouin gain spectrum peak. The double-Brillouin peak fiber can serve as an alternative to other fibers for strain and temperature measurement, eliminating the need for complex monitoring setups and reducing measurement errors. It is highly recommended for long-distance natural gas pipeline monitoring where discriminative strain and temperature measurement is crucial.
Article
Optics
Nageswara Lalam, Hari Bhatta, Xiaoguang Sun, Ping Lu, Paul Ohodnicki, Michael p. Buric, Ruishu Wright
Summary: In this paper, a multi-parameter fiber sensing system based on stimulated Brillouin scattering in a double-Brillouin peak specialty fiber is demonstrated. The system enhances the Brillouin gain response and achieves discriminative measurement of strain and temperature.
Article
Chemistry, Analytical
Christoph K. Thomas, Jannis-Michael Huss, Mohammad Abdoli, Tim Huttarsch, Johann Schneider
Summary: This article presents the design and evaluation results of a novel Solid-Phase Bath (SoPhaB) using ultrafine copper instead of traditional liquid-phase water bath for Fiber-Optic Distributed Sensing (FODS) applications. The SoPhaB, with its thermoelectric heating and/or cooling system, provides a reliable and accurate reference section for translating primary measured intensities to temperature signals.
Article
Optics
Christos Karapanagiotis, Konstantin Hicke, Aleksander Wosniok, Katerina Krebber
Summary: In this paper, we report the first distributed relative humidity sensing in silica polyimide-coated optical fibers using Brillouin optical frequency domain analysis (BOFDA). The linear regression algorithm, a simple and well-interpretable machine learning and statistics method, is employed with the Brillouin frequency shifts and linewidths of the fiber's multipeak Brillouin spectrum as features. Machine learning concepts are utilized to estimate the model's uncertainties and select the most influential features to improve the regression algorithm's effectiveness. The model can also provide distributed temperature estimation simultaneously, addressing the cross-sensitivity effects.
Article
Geochemistry & Geophysics
Arantza Ugalde, Carlos Becerril, Antonio Villasenor, Cesar R. Ranero, Maria R. Fernandez-Ruiz, Sonia Martin-Lopez, Miguel Gonzalez-Herraez, Hugo F. Martins
Summary: In this study, 70 days of distributed acoustic sensing (DAS) recordings were conducted using an undersea fiber-optic telecommunication cable. The results show that the cable can effectively assess seismic activity in remote oceanic areas, capturing various nonseismic and seismic signals.
SEISMOLOGICAL RESEARCH LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Regina Magalhaes, Tiago Neves, Lorenzo Scherino, Sonia Martin-Lopez, Hugo F. Martins
Summary: Distributed Acoustic Sensing (DAS) based on chirped pulse coherent reflectometry technique is capable of providing spatially-resolved distributed measurements of physical quantities along an optical fiber. However, the technique is prone to anomalous estimations and cumulative errors. This study analyzes the errors and proposes strategies and processing methods to achieve unprecedented temperature stability.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Review
Chemistry, Analytical
Mingming Tan, Pawel Rosa, Tu T. Nguyen, Mohammad A. Z. Al-Khateeb, Md. Asif Iqbal, Tianhua Xu, Feng Wen, Juan D. Ania-Castanon, Andrew D. Ellis
Summary: This paper reviews different designs of distributed Raman amplifiers proposed to minimize the signal power profile asymmetry in mid-link optical phase conjugation systems. The paper demonstrates how symmetrical signal power profiles can be achieved using various distributed Raman amplification techniques, both in single-span and multi-span scenarios. Additionally, the paper shows the predicted reduction in Kerr nonlinear product and performance in in-line/long-haul transmission using numerical simulations.
Article
Engineering, Electrical & Electronic
Maria R. Fernandez-Ruiz, Hugo F. Martins, Ethan F. Williams, Carlos Becerril, Regina Magalhaes, Luis Costa, Sonia Martin-Lopez, Zhensheng Jia, Zhongwen Zhan, Miguel Gonzalez-Herraez
Summary: Distributed acoustic sensing (DAS) using optical fibers provides real-time observation of physical perturbations, making it a valuable tool in seismic monitoring. Repurposing existing optical fiber networks allows for convenient near surface monitoring.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Francesca Gallazzi, Ines Caceres, Laura Monroy, Javier Nuno, Concepcion Pulido, Pedro Corredera, Fernando B. Naranjo, Miguel Gonzalez-Herraez, Juan Diego Ania Castanon
Summary: The application of a recently demonstrated mode-locked ultralong pulsed fibre ring laser architecture (Gallazzi et al., 2021) for generating supercontinuum from a pulsed output at 1.56 mu m in standard single-mode telecommunication fibre was experimentally demonstrated. The impact of broadening fibre, dynamic switching between different harmonic modes, and the influence of laser polarization on the properties of the generated supercontinuum were studied for three different kinds of telecommunication fibre. Flexible spectral broadening beyond 200 nm was obtained with good temporal correlation and pulse compression from 240 fs down to 50 fs.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Oceanography
Ethan F. Williams, Zhongwen Zhan, Hugo F. Martins, Maria R. Fernandez-Ruiz, Sonia Martin-Lopez, Miguel Gonzalez-Herraez, Jorn Callies
Summary: The development of ambient noise interferometry has revolutionized seismology and acoustics, but its application in oceanography has been limited due to sparse instrumentation. However, the use of ocean-bottom distributed acoustic sensing (OBDAS) allows for the observation of ocean waves and the application of ambient noise interferometry. This study demonstrates the application of ambient noise interferometry to surface gravity waves observed on an OBDAS array, providing continuous measurements of current velocity with high resolution.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Engineering, Electrical & Electronic
Javier Preciado-Garbayo, Miguel Soriano-Amat, Pascual Sevillano, David Izquierdo, Hugo F. Martins, Sonia Martin-Lopez, Miguel Gonzalez-Herraez, Maria R. Fernandez-Ruiz, Juan J. Martinez
Summary: This letter demonstrates the capabilities of time-expanded phase-sensitive optical time-domain reflectometry (TE Phi-OTDR) using binary sequences. The presented approach allows for a customized distributed optical fiber sensor by changing the length of the binary sequence and the reference clock frequencies. The use of large binary sequences eliminates the need for arbitrary signal generators and enables simple and cost-effective creation of dual comb spectra.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Miguel Soriano-Amat, Hugo F. Martins, Vicente Duran, Pablo Fermoso, Sonia Martin-Lopez, Miguel Gonzalez-Herraez, Maria R. Fernandez-Ruiz
Summary: Phase sensitive (TE-?)OTDR is a distributed fiber sensing technique that uses an electro-optic dual frequency comb (DFC) scheme, providing high spatial resolution with lower detection bandwidths compared to conventional phi OTDR systems. The limitations on resolution, range, and sensing bandwidth in TE-?OTDR are relaxed by implementing two frequency combs with quasi-integer-ratio repetition rates. The use of a rubidium atomic clock allows for up to 10(5) sensing points along 2 km of fiber with tens of Hz sensing bandwidth.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Miguel Soriano-Amat, Hugo F. Martins, Sonia Martin-Lopez, Miguel Gonzalez-Herraez, Maria R. Fernandez-Ruiz, Vicente Duran
Summary: TE-fOTDR is a distributed optical fiber sensing technique that uses the interference of two mutually coherent optical frequency combs. It allows for distributed acoustic sensing with centimeter resolution and megahertz range detection bandwidth. In this paper, the authors demonstrate that TE-fOTDR can be achieved with low-frequency electronics for both signal generation and detection, resulting in a simple, compact, low-cost and potentially field-deployable sensor. High-resolution distributed sensing is carried out without the need for coding strategies or enhanced backscatter fibers.
Article
Optics
Tiago F. P. Neves, Lorenzo Scherino, Remy Bernard, Monika Bouet, Aymeric Pastre, Regina Magalhaes, Sonia Martin-Lopez, Hugo F. Martins, Paolo Petagna, Luc Thevenaz
Summary: This paper presents two innovative optical fibers that are insensitive to humidity and exhibit good performance over a temperature range of -20°C to 55°C. The fibers achieve high resolution and fast response time and have been tested under controlled conditions.
Article
Engineering, Electrical & Electronic
Maria R. Fernandez-Ruiz, Miguel Soriano-Amat, Vicente Duran, Hugo F. Martins, Sonia Martin-Lopez, Miguel Gonzalez-Herraez
Summary: Distributed optical fiber sensing (DOFS) technology has witnessed remarkable growth in various fields. A particularly interesting technique, phase-sensitive Optical Time-Domain Reflectometry (fOTDR), enables real-time monitoring over a large number of sensing points. Recently, a novel approach called time-expanded (TE) fOTDR has been introduced, which combines the advantages of long range and fast response of fOTDR with high spatial resolution. This approach utilizes an interferometric scheme and achieves high-resolution sensing with low detection and acquisition bandwidth.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Miguel Soriano-Amat, Philippe Guay, Hugo F. Martins, Sonia Martin-Lopez, Miguel Gonzalez-Herraez, Maria R. Fernandez-Ruiz, Jerome Genest
Summary: Time-expanded phase-sensitive optical time-domain reflectometry is a distributed optical fiber sensing technology that enables high spatial resolution measurements. An optimized scheme with enhanced energy and spectral efficiencies, as well as the introduction of an optical hybrid, allows for achieving a spatial resolution of 5 mm.
Article
Engineering, Electrical & Electronic
Miguel Tapiador, Camilo Escobar-Vera, Miguel Soriano-Amat, Sonia Martin-Lopez, Miguel Gonzalez-Herraez, Alvaro Hernandez, Maria R. Fernandez-Ruiz
Summary: This paper presents the definition and implementation of a SoC architecture based on FPGA chip for the generation and transmission of PRBS in dual comb spectroscopy. The proposed design has been experimentally validated and successfully applied to characterize the absorption of hydrogen cyanide gas.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Proceedings Paper
Optics
Miguel Gonzalez-Herraez, Miguel Soriano-Amat, Vicente Duran, Hugo F. Martins, Sonia Martin-Lopez, Maria R. Fernandez-Ruiz
Summary: This study presents a novel dual-comb technique that achieves a customized temporal expansion of the time-domain trace in a phase-sensitive reflectometer. It enables the dynamic interrogation of strain/temperature in optical fibers with high spatial resolution using only low-bandwidth photodetection.
2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)
(2022)
Article
Computer Science, Information Systems
Malak Galal, Suneetha Sebastian, Luc Thevenaz
Summary: This paper introduces a method to improve the signal-to-noise ratio of distributed optical fiber sensor systems by increasing the backreflected signal of the fibers, known as reflection-enhanced fibers. It also emphasizes the potential issue of signal-dependent noises accompanied by the enhanced signal. Experimental results show that reflection-enhanced fibers outperform standard single-mode fibers in distributed temperature measurements.
