Journal ArticleDOI
Using simplex codes to improve OTDR sensitivity
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TLDR
A coding technique for improving the sensitivity of optical time domain reflectometry (OTDR) using optical codes derived from Hadamard matrices and does not use correlation is proposed.Abstract:
A coding technique for improving the sensitivity of optical time domain reflectometry (OTDR) is proposed. The technique uses optical codes derived from Hadamard matrices and does not use correlation. The sensitivity realized by this new method is shown to be superior to that obtained using Golay codes. >read more
Citations
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[INVITED] State of the art of Brillouin fiber-optic distributed sensing
Avi Motil,Arik Bergman,Moshe Tur +2 more
TL;DR: In this article, the state of the art of the leading Brillouin interrogation methods, with emphasis on the significant progress made in the last 3 years, are described, as well as a short introduction to coding, which has proven instrumental in many recently obtained performance records.
Journal ArticleDOI
A Review of Distributed Fibre Optic Sensors for Geo-Hydrological Applications
TL;DR: In this article, the application of distributed optical fiber sensors to geo-hydrological monitoring is reviewed and discussed, along with basic principles and main acquisition techniques, and the emphasis is placed on those related to soil levees, slopes/landslide, and ground subsidence that constitute a significant percentage of current geohazards.
Journal ArticleDOI
Distributed Optical Fiber Sensing Based on Rayleigh Scattering
Luca Palmieri,Luca Schenato +1 more
TL;DR: In this paper, the authors focus on Rayleigh-based distributed optical fiber sensors, which are based on the scattering processes that originate from the interaction between light and matter, and provide unprecedented features, such as the ability of monitoring varia- tions of the observed physical field with spatial continuity along the fiber.
Journal ArticleDOI
Extending the Real Remoteness of Long-Range Brillouin Optical Time-Domain Fiber Analyzers
Marcelo A. Soto,Xabier Angulo-Vinuesa,Sonia Martin-Lopez,Sanghoon Chin,Juan Diego Ania-Castanon,Pedro Corredera,Etienne Rochat,Miguel Gonzalez-Herraez,Luc Thévenaz +8 more
TL;DR: In this paper, a distributed optical fiber sensor based on Brillouin optical time-domain analysis is considerably extended using seeded second-order Raman amplification and optical pulse coding, in which half of the fiber is used for sensing purposes, and the other half is used to carry the optical signals to the most distant sensing point.
Journal ArticleDOI
Analysis of pulse modulation format in coded BOTDA sensors
TL;DR: A theoretical and experimental analysis of the impact of pulse modulation format on Brillouin optical time-domain analysis (BOTDA) sensors using pulse coding techniques has been carried out, showing that low duty-cycle values are able to effectively suppress the induced distortions in the BGS and allow for spatially-accurate, high-resolution strain and temperature measurements.
References
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Journal ArticleDOI
Real-time long range complementary correlation optical time domain reflectometer
Moshe Nazarathy,Steven A. Newton,R.P. Giffard,D.S. Moberly,F. Sischka,W. R. Trutna,S. Foster +6 more
TL;DR: In this article, the improved performance of an optical time-domain reflectometer (OTDR) through the application of a correlation technique using codes with complementary autocorrelation properties is discussed.
Journal ArticleDOI
OTDR in single-mode fibre at 1.5 μm using homodyne detection
TL;DR: In this article, the first application of homodyne detection to optical time-domain reflectometry (OTDR) in single-mode fibres at a wavelength of 1.52 μm was reported.
Journal ArticleDOI
Complementary correlation OTDR with three codewords
TL;DR: A complementary correlation OTDR technique based on probing with only three codewords and processing with onlyThree correlations is presented, for any power of two code length.
Journal ArticleDOI
Optical orthogonal pulse compression codes by hopping
TL;DR: In this paper, a simple digital processing technique for using standard M sequences or quadratic residue codes in such a way that their optical correlation is truly orthogonal is described.
Journal ArticleDOI
Optical Barker codes
P.S. Moharir,A. Selvarajan +1 more
TL;DR: Certain binary codes having good autocorrelation properties akin to Barker codes are studied to find out what makes them good binary codes to study.