BOTDA using channel estimation with direct-detection optical OFDM technique

Zhao, Can; Tang, Ming; Wang, Liang; Wu, Hao; Zhao, Zhiyong; Dang, Yunli; Wu, Jiadi; Fu, Songnian; Liu, Deming; Shum, Ping

doi:10.1364/oe.25.012698

Cited by 33 publications

(17 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5, and also indicating a good agreement between the experimental and theoretical results. This analysis indicates that the poor SNR performance when K = 1 given by equation (8) can be greatly improved by reducing the value of K, and since both the noise reduction factor and the number of tracking steps exclusively depend on the value of K, the relation between these two parameters can be obtained by mapping Fig. 9 into Fig.…”

Section: Resultsmentioning

confidence: 98%

“…One of these methods circumvents the slow frequency switching time required during scanning, primarily by pre-loading the full set of scanned pump-probe frequency offsets in an arbitrary waveform generator (AWG), commonly designated as fast BOTDA (F-BOTDA) technique [4], [5]. Another way to do without the lengthy frequency scan is to exploit optical frequency combs: the BGS information can be retrieved by generating multi-pump and multi-probe tones simultaneously in a sweep-free BOTDA (SF-BOTDA) technique [6], or utilizing advanced algorithm based on orthogonal frequency division multiplexing (OFDM) [7], [8]. Ultra-fast Brillouin distributed sensing can be realized by reducing the scan to its merest expression using a single probe frequency, as demonstrated in the slope-assisted BOTDA (SA-BOTDA) technique [9]- [11].…”

mentioning

confidence: 99%

“…Based on the working principle of SA-BOTDA, several techniques have been proposed to extend the covered BFS range [12]- [15]. However, the reduction of the BOTDA measurement time using the above-mentioned techniques turns out to systematically degrade other specifications, like a poorer spatial resolution [7], [8], a larger BFS uncertainty [4]- [15], or a limited temperature/strain measurement range [9]- [15].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Brillouin Distributed Optical Fiber Sensor Based on a Closed-Loop Configuration

Yang

Soto

Chow

et al. 2018

J. Lightwave Technol.

View full text Add to dashboard Cite

Abstract-A Brillouin optical time-domain analysis (BOTDA) method based on a closed-loop control system is proposed to track fast variations of the Brillouin frequency shift along the sensing fiber. While the method eliminates the gain spectral scanning, the exact distributed Brillouin frequency profile is retrieved directly from the output of a closed-loop controller with no need of postprocessing. Moreover, as the operating frequency is being continuously updated to follow the Brillouin frequency change, an unlimited temperature or strain measurement range can be achieved. Both theoretical analysis and experimental results validate that the closed-loop-controlled BOTDA acts as a low-pass filter that considerably rejects the noise from photodetector, with an efficiency that fundamentally outperforms basic averaging. By optimizing the closed-loop parameters, the measurement time is reduced from a few minutes to a couple of seconds compared with standard BOTDA, i.e., two orders of magnitude improvement in terms of measurement speed, while keeping the same accuracy and measurement conditions. If the sampling time interval that is limited by our instrument can be further reduced, the method offers the potentiality of km-range sensing with sub-second measurement time, with an unmatched favorable tradeoff between measurand accuracy and closed-loop delay.Index Terms-Brillouin scattering, distributed optical fiber sensors, optical fibers, strain and temperature measurements.

show abstract

Section: Resultsmentioning

confidence: 98%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Brillouin Distributed Optical Fiber Sensor Based on a Closed-Loop Configuration

Yang

Soto

Chow

et al. 2018

J. Lightwave Technol.

View full text Add to dashboard Cite

show abstract

“…For distributed Brillouin sensors, data processing time is one of the key factors affecting the system response time. Especially for high-speed acquisition systems, the LCF has become a bottleneck 16,17 . It takes approximately 0.129 s for the CNN to process 1000 BGSs based on a Python environment running on a PC with an AMD Ryzen 7 1700 eight-core processor and a Nvidia GeForce GTX 1070 Ti (8 GB) GPU.…”

Section: Processing Timementioning

confidence: 99%

Distributed Brillouin frequency shift extraction via a convolutional neural network

Chang¹,

Wu²,

Zhao³

et al. 2020

Photon. Res.

Self Cite

View full text Add to dashboard Cite

Distributed optical fiber Brillouin sensors detect the temperature and strain along a fiber according to the local Brillouin frequency shift, which is usually calculated by the measured Brillouin spectrum using Lorentzian curve fitting. In addition, cross-correlation, principal component analysis, and machine learning methods have been proposed for the more efficient extraction of Brillouin frequency shifts. However, existing methods only process the Brillouin spectrum individually, ignoring the correlation in the time domain, indicating that there is still room for improvement. Here, we propose and experimentally demonstrate a full convolution neural network to extract the distributed Brillouin frequency shift directly from the measured two-dimensional data. Simulated ideal Brillouin spectrum with various parameters are used to train the network. Both the simulation and experimental results show that the extraction accuracy of the network is better than that of the traditional curve fitting algorithm with a much shorter processing time. This network has good universality and robustness and can effectively improve the performances of existing Brillouin sensors.

show abstract

“…Fortunately, the BOTDA can provide high-accuracy absolute strain information by using the BFS 31 , while it is not able to realize nano-strain measurements due to its low strain resolution. For the fast Brillouin sensing, several impressive technologies have been proposed to expedite the measurement speed, such as the optical frequency comb technique 32,33 , slope-assisted method 13,34 , frequency-agile technique 31 , optical frequency division multiplexing technique 35,36 , and optical chirp chain technique 37 . Based on the above analysis, both the φ-OTDR and BOTDA sensors are able to realize the dynamic strain measurements, but the intended applications are different for these two sensors.…”

Section: Introductionmentioning

confidence: 99%

High-sensitivity distributed dynamic strain sensing by combining Rayleigh and Brillouin scattering

Wang¹,

Ba²,

Chu³

et al. 2020

Opto-Electronic Advances

View full text Add to dashboard Cite

The phase-sensitive optical time-domain reflectometry (φ-OTDR) is a good candidate for distributed dynamic strain sensing, due to its high sensitivity and fast measurement, which has already been widely used in intrusion monitoring, geophysical exploration, etc. For the frequency scanning based φ-OTDR, the phase change manifests itself as a shift of the intensity distribution. The correlation between the reference and measured spectra is employed for relative strain demodulation, which has imposed the continuous measurement for the absolute strain demodulation. Fortunately, the Brillouin optical time domain analysis (BOTDA) allows for the absolute strain demodulation with only one measurement. In this work, the combination of the φ-OTDR and BOTDA has been proposed and demonstrated by using the same set of frequency-scanning optical pulses, and the frequency-agile technique is also introduced for fast measurements. A 9.9 Hz vibration with a strain range of 500 nε has been measured under two different absolute strains (296.7με and 554.8 με) by integrating the Rayleigh and Brillouin information. The sub-micro strain vibration is demonstrated by the φ-OTDR signal with a high sensitivity of 6.8 nε, while the absolute strain is measured by the BOTDA signal with an accuracy of 5.4 με. The proposed sensor allows for dynamic absolute strain measurements with a high sensitivity, thus opening a door for new possibilities which are yet to be explored.

show abstract

BOTDA using channel estimation with direct-detection optical OFDM technique

Cited by 33 publications

References 19 publications

Brillouin Distributed Optical Fiber Sensor Based on a Closed-Loop Configuration

Brillouin Distributed Optical Fiber Sensor Based on a Closed-Loop Configuration

Distributed Brillouin frequency shift extraction via a convolutional neural network

High-sensitivity distributed dynamic strain sensing by combining Rayleigh and Brillouin scattering

Contact Info

Product

Resources

About