scholarly journals Application of Brillouin scattering in optic-fiber sensors

2021 ◽  
Vol 2091 (1) ◽  
pp. 012070
Author(s):  
I V Bogachkov ◽  
N I Gorlov ◽  
E T Kitova ◽  
T I Monastyrskaya
Keyword(s):  
Dynamic Range ◽  
Brillouin Scattering ◽  
Spectral Component ◽  
Electric Power Industry ◽  
Oil And Gas Industry ◽  
Optic Fiber ◽  
Software Environment ◽  
Metrological Analysis ◽  
Physical Strain ◽  
Fiber Sensors

Abstract The article analyses possible applications for Brillouin scattering in optic-fiber sensors. They make it possible to do temperature and physical strain measurements with high accuracy for long line sections. The functional dependences of the output signals characteristics on parameters measured by the sensors are studied. Of particular interest are the results of the analysis of the spectral component shifts in the Brillouin light scattering depending on the fiber elongation and temperature. After a brief review of the basic theoretical principles the results of some researches aimed to expand the dynamic range and to increase spatial resolution. The results of simulation in professional design software environment OptiSystem 17.1. are described. The results are obtained by experimental research based on Brillouin reflectometer AQ8603 manufactured by “ANDO” (Japan). They show that it is possible to implement optic-fiber sensors based on Brillouin scattering in telecommunication systems, oil and gas industry, in electric-power industry, construction, aviation and space industry. The objectives for further research are to perform metrological analysis at all stages of the method implementation, to complete the base of Brillouin spectrograms for optical fiber of various types and to improve algorithms for automated processing spectra in order to expand functionality of the systems.

scholarly journals Fast Measurement of Brillouin Frequency Shift in Optical Fiber Based on a Novel Feedforward Neural Network

Photonics ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 474
Author(s):  
Fen Xiao ◽  
Mingxing Lv ◽  
Xinwan Li
Keyword(s):  
Neural Network ◽  
Optical Fiber ◽  
Frequency Shift ◽  
Brillouin Scattering ◽  
Principal Component ◽  
Feedforward Neural Network ◽  
Gain Spectrum ◽  
Fiber Sensors ◽  
Brillouin Gain ◽  
Distributed Optical Fiber

Brillouin scattering-based distributed optical fiber sensors have been successfully employed in various applications in recent decades, because of benefits such as small size, light weight, electromagnetic immunity, and continuous monitoring of temperature and strain. However, the data processing requirements for the Brillouin Gain Spectrum (BGS) restrict further improvement of monitoring performance and limit the application of real-time measurements. Studies using Feedforward Neural Network (FNN) to measure Brillouin Frequency Shift (BFS) have been performed in recent years to validate the possibility of improving measurement performance. In this work, a novel FNN that is 3 times faster than previous FNNs is proposed to improve BFS measurement performance. More specifically, after the original Brillouin Gain Spectrum (BGS) is preprocessed by Principal Component Analysis (PCA), the data are fed into the Feedforward Neural Network (FNN) to predict BFS.

scholarly journals An 11-bit High Dynamic Range (HDR) Luminance Display and Its Use to Discover Contextual Mechanisms of Real-World Luminance Normalization for Visual Acuity and Target Discrimination

2019 ◽  
Author(s):  
Chou P Hung ◽  
Chloe Callahan-Flintoft ◽  
Paul D Fedele ◽  
Kim F Fluitt ◽  
Onyekachi Odoemene ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Real World ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Automatic Target Recognition ◽  
Facilitation Effect ◽  
Software Environment ◽  
Temporal Precision ◽  
Central Target ◽  
High Dynamic

ABSTRACTLuminance can vary widely when scanning across a scene, by up to 10^9 to 1, requiring multiple normalizing mechanisms spanning from the retina to cortex to support visual acuity and recognition. Vision models based on standard dynamic range luminance contrast ratios below 100 to 1 have limited ability to generalize to real-world scenes with contrast ratios over 10,000 to 1 (high dynamic range [HDR]). Understanding and modeling brain mechanisms of HDR luminance normalization is thus important for military applications, including automatic target recognition, display tone mapping, and camouflage. Yet, computer display of HDR stimuli was until recently unavailable or impractical for research. Here we describe procedures for setup, calibration, and precision check of an HDR display system with over 100,000 to 1 luminance dynamic range (650–0.0065 cd/m^2), pseudo 11-bit grayscale precision, and 3-ms temporal precision in the MATLAB/Psychtoolbox software environment. The setup is synchronized with electroencephalography and IR eye-tracking measurements. We report measures of HDR visual acuity and the discovery of a novel phenomenon—that abrupt darkening (from 400 to 4 cd/m^2) engages contextual facilitation, distorting the perceived orientation of a high-contrast central target. Surprisingly, the facilitation effect depended on luminance similarity, contradicting both classic divisive and subtractive models of contextual normalization.

scholarly journals Truly Distributed Optical Fiber Sensors for Structural Health Monitoring: From the Telecommunication Optical Fiber Drawling Tower to Water Leakage Detection in Dikes and Concrete Structure Strain Monitoring

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Jean-Marie Henault ◽  
Gautier Moreau ◽  
Sylvain Blairon ◽  
Jean Salin ◽  
Jean-Robert Courivaud ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Brillouin Scattering ◽  
Optical Fiber Sensors ◽  
Leakage Detection ◽  
Strain Sensing ◽  
Water Leakage ◽  
Fiber Sensors ◽  
Practical Applications ◽  
Water Leakage Detection

Although optical fiber sensors have been developed for 30 years, there is a gap between lab experiments and field applications. This article focuses on specific methods developed to evaluate the whole sensing chain, with an emphasis on (i) commercially-available optoelectronic instruments and (ii) sensing cable. A number of additional considerations for a successful pairing of these two must be taken into account for successful field applications. These considerations are further developed within this article and illustrated with practical applications of water leakage detection in dikes and concrete structures monitoring, making use of distributed temperature and strain sensing based on Rayleigh, Raman, and Brillouin scattering in optical fibers. They include an adequate choice of working wavelengths, dedicated localization processes, choices of connector type, and further include a useful selection of traditional reference sensors to be installed nearby the optical fiber sensors, as well as temperature compensation in case of strain sensing.

scholarly journals Distributed Dynamic Strain Sensing Based on Brillouin Scattering in Optical Fibers

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5629
Author(s):  
Agnese Coscetta ◽  
Aldo Minardo ◽  
Luigi Zeni
Keyword(s):  
Optical Fiber ◽  
Brillouin Scattering ◽  
Traffic Monitoring ◽  
Optical Fiber Sensors ◽  
Dynamic Strain ◽  
Dynamic Measurements ◽  
Research Activity ◽  
Fiber Sensors ◽  
Railway Traffic ◽  
Distributed Optical Fiber

Over the past three decades, extensive research activity on Brillouin scattering-based distributed optical fiber sensors has led to the availability of commercial instruments capable of measuring the static temperature/strain distribution over kilometer distances and with high spatial resolution, with applications typically covering structural and environmental monitoring. At the same time, the interest in dynamic measurements has rapidly grown due to the relevant number of applications which could benefit from this technology, including structural analysis for defect identification, vibration detection, railway traffic monitoring, shock events detection, and so on. In this paper, we present an overview of the recent advances in Brillouin-based distributed optical fiber sensors for dynamic sensing. The aspects of the Brillouin scattering process relevant in distributed dynamic measurements are analyzed, and the different techniques are compared in terms of performance and hardware complexity.

scholarly journals Recent Progress in Brillouin Scattering Based Fiber Sensors

Sensors ◽  
2011 ◽  
Vol 11 (4) ◽  
pp. 4152-4187 ◽  
Author(s):  
Xiaoyi Bao ◽  
Liang Chen
Keyword(s):  
Recent Progress ◽  
Brillouin Scattering ◽  
Fiber Sensors

The Application of the Optic Sensor in the Monitoring on the Transmission Lines

2012 ◽  
Vol 263-266 ◽  
pp. 939-942
Author(s):  
Ya Fei Hou ◽  
Rui Ke ◽  
Yi Ma ◽  
Ran Huang ◽  
Wei Deng
Keyword(s):  
Electric Field ◽  
Transmission Lines ◽  
Fiber Composite ◽  
Optic Fiber ◽  
Monitoring Methods ◽  
Operation Performance ◽  
Fiber Sensors ◽  
Insulator Surface ◽  
Detection Technology ◽  
Surface Electric Field

Three technologies of insulator online monitoring based on optic fiber sensors is described in proposed paper, including optic fiber sensor salt density technology, optical fiber composite insulator monitoring technology and optical sensor insulator surface electric field detection technology. According to measuring insulator surface ESDD, the internal stress and the temperature distribution of the composite insulators and insulator surface electric field values. these technology can monitor the operation performance of insulator. These techniques that improve the existing insulators monitoring methods has a strong innovative and practical application prospects.

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