Article
Engineering, Electrical & Electronic
Scott Foster
Summary: Fundamental thermodynamic limits on the strain resolution of a class of fiber optic distributed acoustic sensing techniques based on optical time domain reflectometry have been derived, showing a lower limit of around 10(-14)strain/root Hz for a 2 m long (10 ns) optical pulse. These limits suggest that monitoring unmodified fiber optic cables is unlikely to achieve sensing performance comparable to engineered acoustic sensors.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Chao Du, Cailing Fu, Pengfei Li, Yanjie Meng, Huajian Zhong, Bin Du, Kuikui Guo, Lin Chen, Yiping Wang, Jun He
Summary: A high-spatial-resolution strain sensor with 2.0 mm resolution based on Rayleigh-scattering-enhanced single-mode fiber (E-SMF) was demonstrated using direct UV laser exposure. The enhancement of Rayleigh-scattering intensity was tunable by adjusting exposure parameters. An E-SMF with 37.3 dB RS enhancement was achieved in only 100 s exposure time. The strain profiles of E-SMF could be accurately demodulated at a spatial resolution of 2.0 mm using traditional cross-correlation algorithm for strain from 200 to 2600 μe, compared to un-exposed SMF (UE-SMF).
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Review
Engineering, Electrical & Electronic
Daniele Tosi, Carlo Molardi, Marzhan Sypabekova, Wilfried Blanc
Summary: Optical Backscatter Reflectometry (OBR) is an advanced distributed sensing technique that utilizes optical fibers to detect and localize physical parameters with spatial resolution below the millimeter. By tailoring the Rayleigh scattering properties of optical fibers and enhancing backscattering contents, it is possible to create 2 and 3-dimensional sensing networks, extending OBR to multi-dimensional and even biosensing applications. This work provides a tutorial on distributed optical fiber sensors with enhanced backscattering and discusses the design of sensing networks with these fibers, while also reviewing main applications and emerging topics.
IEEE SENSORS JOURNAL
(2021)
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
Computer Science, Information Systems
Nageswara Lalam, Paul S. Westbrook, Jie Li, Ping Lu, Michael P. Buric
Summary: This paper presents a phase-sensitive optical time domain reflectometry (8-OTDR) based on Rayleigh enhanced optical fiber to enhance the system signal-to-noise ratio. Experimental results show a 14 dB improvement in the measured SNRs of peaks at the end of the specialty sensing fiber. A wide range of vibration frequencies from 50 Hz to 15 kHz have been experimentally demonstrated, overcoming the limitations of conventional 8-OTDR systems and significantly enhancing vibration sensing performance.
Article
Engineering, Electrical & Electronic
Hua Zheng, Jingdong Zhang, Nan Guo, Tao Zhu
Summary: This article discusses the research progress of distributed optical fiber sensors (DOFS) for dynamic measurement. By introducing the basic principles and latest technologies, it demonstrates the potential applications of DOFS in dynamic parameter measurement and multi-parameter sensing.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Pedro Tovar, Bismarck Costa Lima, Jean Pierre von der Weid
Summary: This work thoroughly analyzes the intensity fluctuations of Rayleigh backscattered coherent light in single mode optical fibers. A theoretical model is developed based on the intermediate range order of silica glasses and the residual stress of optical fibers to calculate the intensity fluctuations in the optical frequency domain. The comparison between numerical simulation results and experimental results in the time domain supports the conclusion that Rayleigh backscattering in single mode fibers is an ergodic process exhibiting ergodicity in the time-frequency sense, allowing the model to determine the statistical behavior of the backscattered intensity fading.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Computer Science, Hardware & Architecture
Zhensheng Jia, L. Alberto Campos
Summary: Optical fiber transport technology is crucial for fast and affordable bandwidth delivery, with coherent optics now widely utilized in metro networks and showing potential for short-haul applications in edge and access networks.
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)
Article
Engineering, Electrical & Electronic
Xia Gao, Xiaobin Hong, Sheng Wang, Xizi Sun, Liangming Xiong, Jian Wu
Summary: This paper presents a novel single-fiber-based BOTDA technique, in which the counter-propagating probe light is generated by modulating the auxiliary light from the far-end, enabling long-distance sensing and accurate measurements.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Haoyu Wang, Dan Zhang, Kang Ren, Bin Shi, Junyi Guo, Mengya Sun
Summary: This article develops a novel strain-sensitive water leakage sensing optical cable (SL cable) and proposes a new tunnel water leakage distributed monitoring method to overcome the shortcomings of existing methods. The effects of leakage rate, axial load, and layout angle of the SL cable are investigated through experiments, and the high sensitivity and reusability of the SL cable are verified. The results highlight the potential of this method for practical implementation in water leakage monitoring.
IEEE SENSORS JOURNAL
(2023)
Article
Optics
Daniele Tosi, Carlo Molardi, Wilfried Blanc
Summary: The article introduces a low-loss enhanced backscattering fiber doped with MgO-based nanoparticles for distributed sensing applications, which shows a significant scattering increment and low losses. By utilizing scattering-level multiplexing, an extension of sensing length up to 2.4-4.0 times can be achieved.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Polymer Science
Xin Lu, Konstantin Hicke, Mathias Breithaupt, Christoph Strangfeld
Summary: This study presents a preliminary investigation on distributed humidity monitoring during the drying process of concrete using embedded polymer optical fiber (POF). Experimental results indicate that the signal received at 650 nm increases, while the fiber attenuation factor at 500 nm clearly increases, which is consistent with the measurement result of the electrical humidity sensors embedded in the concrete sample.
Article
Engineering, Electrical & Electronic
Mudabbir Badar, Ping Lu, Qirui Wang, Thomas Boyer, Kevin P. Chen, Paul R. Ohodnicki
Summary: Timely detection of incipient faults in power transformers is crucial to prevent malfunction. Monitoring transformer insulation oil, particularly its temperature, is essential as it provides key diagnostic information. Distributed optical fiber sensors have advantages over traditional methods, as shown in this study on a 100 kVA distribution transformer. Results indicate good agreement between conventional methods and distributed fiber temperature sensors.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Yanjie Meng, Cailing Fu, Chao Du, Lin Chen, Huajian Zhong, Pengfei Li, Baijie Xu, Bin Du, Jun He, Yiping Wang
Summary: A method using two outer cores of multicore fiber without calibration and OFDR, as well as a complement using three outer cores of multicore fiber, were proposed for three-dimensional shape sensing. By integrating all fiber shape from all cores combinations, a higher accuracy in reconstructed shape was obtained.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
