- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Cross correlation peak-seeking technique of BOTDR based on the incomplete Brillouin spectrum
摘要： Considered the limitation of sweeping frequency technique, Brillouin optical time domain reflectometer (BOTDR) can only perceive slow external interference. It greatly limits the scope of application. For perceiving rapid external interference, a method of cross correlation peak-seeking technique based on incomplete Brillouin spectrum (IBS) is proposed, and the feasibility of the method is verified under the background of the monitoring of sound barriers along the high-speed railway. The numerical simulation results indicate that the probability that obtains an accurate peak frequency error within the 0.50 MHz can reach 49/50, when frequency interval for sweeping is 5 MHz and number of splicing IBS is 80. In addition, to select the optimal parameters of the system, we also take a further analysis on the effect of the splicing times and the frequency interval for sweeping on the peak detection accuracy. This method is significant to extend the application of BOTDR from slow changing fields to rapid changing fields.
关键词： Optical time domain reflectometry,Brillouin scattering,Optical fiber measurement applications
更新于2025-09-23 15:22:29
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Transforming the Fiber-Optic Network into a Dense and Ultrasensitive Seismic Sensor Array
摘要： We show a technology capable of performing position-resolved measurement of nanostrain perturbations along a conventional optical fiber cable, with meter-scale resolution. This technology can be deployed in already existing networks to achieve a dense and ultrasensitive seismic sensor array. Applications ranging from seismic protection to chemical sensing are explored.
关键词： seismology,distributed fiber optics sensors,Rayleigh scattering,optical time domain reflectometry,distributed acoustic sensors
更新于2025-09-23 15:22:29
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[IEEE 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Athens, Greece (2018.7.4-2018.7.6)] 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Experimental Verification of the Optimum Diagonal Loading Level for Adaptive Matched Filtering with ?-OTDR System
摘要： Recently, a temporal adaptive matched filtering technique has been proposed to reduce the background noise in phase-sensitive optical time domain reflectometry (φ-OTDR) systems deployed for fibre optic distributed acoustic sensing (DAS) applications. This technique utilizes noise covariance matrix inversion which is estimated from signal-free assumed training samples. The detection performance degradation due to desired signal presence in the training data and the ill-conditioning of the matrix because of the limited training data are conventionally avoided by adding some amount of white noise on the diagonal elements of the covariance matrix. In this paper, the optimum level for this diagonal loading (DL) is investigated for DAS applications and verified with real φ-OTDR data. The optimum DL level which has been analytically proven in beamforming applications is shown to be applicable in the temporal domain noise filtering for DAS applications. The experimental results validate that the optimum DL value is negative.
关键词： diagonal loading,phase-sensitive optical time domain reflectometry (OTDR),distributed vibration sensors,optimum filtering.,Adaptive matched filter
更新于2025-09-23 15:22:29
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Performance Optimization for Phase-Sensitive OTDR Sensing System Based on Multi-Spatial Resolution Analysis
摘要： This paper proposes and demonstrates a phase-sensitive optical time domain reflectometry (Φ-OTDR) sensing system with multi-spatial resolution (MSR) analysis property. With both theoretical analysis and an experiment, the qualitative relationship between spatial resolution (SR), signal-to-noise ratio (SNR) and the length of the vibration region has been revealed, which indicates that choosing a suitable SR to analyze the vibration event can effectively enhance the SNR of a sensing system. The proposed MSR sensing scheme offers a promising solution for the performance optimization of Φ-OTDR sensing systems, which can restore vibration events of different disturbance range with optimum SNR in merely a single measurement while maintaining the same detectable frequency range.
关键词： phase-sensitive optical time domain reflectometry (Φ-OTDR),signal-to-noise ratio (SNR),multi-spatial resolution (MSR) analysis
更新于2025-09-19 17:15:36
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Optical Fiber Vibration Sensor Using Least Mean Square Error Algorithm
摘要： In order to enhance the signal-to-noise ratio (SNR) of a distributed optical fiber vibration sensor based on coherent optical time domain reflectometry (COTDR), a high extinction ratio cascade structure of an acousto-optic modulator and semiconductor optical amplifier is applied. The prior time-frequency analysis and least mean square error algorithm are adopted in the COTDR system for amplitude demodulation and phase demodulation, in order to improve the SNR by noise elimination. The experimental results show that the adaptive filter based on the least mean square error algorithm could realize the extraction of a three-order sinusoidal harmonic signal from strong background noise along the optical fiber and the SNR improvement from 10.4 dB to 42.2 dB. The proposed demodulation algorithm is suitable for the detection of vibration signals with characteristic frequencies in the application of acoustic fault diagnosis for electromechanical devices.
关键词： least mean square error algorithm,optical fiber vibration sensor,semiconductor optical amplifier,coherent optical time domain reflectometry
更新于2025-09-19 17:13:59
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Long-Range Distributed Solar Irradiance Sensing Using Optical Fibers
摘要： Until recently, the amount of solar irradiance reaching the Earth surface was considered to be a steady value over the years. However, there is increasing observational evidence showing that this quantity undergoes substantial variations over time, which need to be addressed in different scenarios ranging from climate change to solar energy applications. With the growing interest in developing solar energy technology with enhanced efficiency and optimized management, the monitoring of solar irradiance at the ground level is now considered to be a fundamental input in the pursuit of that goal. Here, we propose the first fiber-based distributed sensor able of monitoring ground solar irradiance in real time, with meter scale spatial resolutions over distances of several tens of kilometers (up to 100 km). The technique is based on an optical fiber reflectometry technique (CP-φOTDR), which enables real time and long-range high-sensitivity bolometric measurements of solar radiance with a single optical fiber cable and a single interrogator unit. The method is explained and analyzed theoretically. A validation of the method is proposed using a solar simulator irradiating standard optical fibers, where we demonstrate the ability to detect and quantify solar irradiance with less than a 0.1 W/m2 resolution.
关键词： optical time domain reflectometry,photothermal effects,distributed sensing,rayleigh scattering,optical fiber sensors,solar irradiance,solar energy,optical radiation
更新于2025-09-19 17:13:59
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Suppression of amplitude fluctuation in Brillouin optical fiber reflectometry employing polarization beam splitter and pre-amplification technique
摘要： We propose and validate the suppression effect on amplitude fluctuation in Brillouin optical time domain reflectometry sensing system with a polarization beam splitter and pre-amplification technique. The p- and s-components of local oscillator interfere respectively with two halves of Brillouin scattering amplified by a Erbium doped fiber amplifier. Theoretical analysis indicates that the polarization influence on the beat amplitude is eliminated with the proposed scheme; and experimental results show that the amplitude variation along the sensing fiber could be extracted accurately, and the temperature sensing error is about 5%. The proposed method is helpful to improve the measurement accuracy of the BOTDR sensing system.
关键词： Pre-amplification technique,Polarization beam splitter,Brillouin optical time domain reflectometry,Amplitude fluctuation suppression,sensing system
更新于2025-09-19 17:13:59
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Distributed optical fiber sensing: Review and perspective
摘要： Over the past few decades, optical fibers have been widely deployed to implement various applications in high-speed long-distance telecommunication, optical imaging, ultrafast lasers, and optical sensors. Distributed optical fiber sensors characterized by spatially resolved measurements along a single continuous strand of optical fiber have undergone significant improvements in underlying technologies and application scenarios, representing the highest state of the art in optical sensing. This work is focused on a review of three types of distributed optical fiber sensors which are based on Rayleigh, Brillouin, and Raman scattering, and use various demodulation schemes, including optical time-domain reflectometry, optical frequency-domain reflectometry, and related schemes. Recent developments of various distributed optical fiber sensors to provide simultaneous measurements of multiple parameters are analyzed based on their sensing performance, revealing an inherent trade-off between performance parameters such as sensing range, spatial resolution, and sensing resolution. This review highlights the latest progress in distributed optical fiber sensors with an emphasis on energy applications such as energy infrastructure monitoring, power generation system monitoring, oil and gas pipeline monitoring, and geothermal process monitoring. This review aims to clarify challenges and limitations of distributed optical fiber sensors with the goal of providing a pathway to push the limits in distributed optical fiber sensing for practical applications.
关键词： energy applications,Brillouin scattering,Rayleigh scattering,Raman scattering,optical time-domain reflectometry,distributed optical fiber sensing,optical frequency-domain reflectometry
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Bipolar coding for phase-demodulated Φ-OTDR with coherent detection
摘要： The non-return-to-zero bipolar Golay code is successfully employed in phase-demodulated Φ-OTDR utilizing heterodyne detection. Compared with unipolar scenario, the superior performance is demonstrated in 10 km sensing experiment with doubled response bandwidth for perturbation, sub-meter spatial resolution and pico-strain resolution. This work paves the way for optical pulse coding based on bipolar sequences or matrix in Φ-OTDR.
关键词： Phase-sensitive optical time-domain reflectometry,Golay code,Optical fiber sensing
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - The application of PCA on ?-OTDR sensing system for vibration detection
摘要： The paper presents Principal Component Analysis (PCA) technique in denoising phase sensitive optical time domain reflectometry (Φ-OTDR) sensing data for vibration detection. The PCA is one of the most effective techniques used for noise reduction while preserving significant details of the denoised signals. As a result, we outline the basics of PCA and applied on the said data. It demonstrates that the PCA significantly reduced the noise and vibration along the phase trace clearly detected with a significant enhancement of the Signal to Noise ratio (SNR). A theoretical analysis is presented with an experimental demonstration of the vibration sensing range of 1km and a spatial resolution of 10m.
关键词： Denoising,In-phase/Quadrature,Principal Component Analysis,Phase Sensitive Optical Time Domain Reflectometry,Signal to Noise Ratio
更新于2025-09-16 10:30:52