Rayleigh scattering in fluoride glass optical fibres

1983 ◽  
Vol 19 (5) ◽  
pp. 165 ◽  
Author(s):  
D.C. Tran ◽  
K.H. Levin ◽  
C.F. Fisher ◽  
M.J. Burk ◽  
G.H. Sigel
Keyword(s):  
Rayleigh Scattering ◽  
Fluoride Glass ◽  
Optical Fibres

scholarly journals Hollow core optical fibres with comparable attenuation to silica fibres between 600 and 1100 nm

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Hesham Sakr ◽  
Yong Chen ◽  
Gregory T. Jasion ◽  
Thomas D. Bradley ◽  
John R. Hayes ◽  
...  
Keyword(s):  
Rayleigh Scattering ◽  
Density Fluctuations ◽  
Power Delivery ◽  
Optical Data ◽  
Optical Fibres ◽  
Hollow Core ◽  
Quantum Communications ◽  
Scattering Loss ◽  
Air Core ◽  
Solid Glass

AbstractFor over 50 years, pure or doped silica glass optical fibres have been an unrivalled platform for the transmission of laser light and optical data at wavelengths from the visible to the near infra-red. Rayleigh scattering, arising from frozen-in density fluctuations in the glass, fundamentally limits the minimum attenuation of these fibres and hence restricts their application, especially at shorter wavelengths. Guiding light in hollow (air) core fibres offers a potential way to overcome this insurmountable attenuation limit set by the glass’s scattering, but requires reduction of all the other loss-inducing mechanisms. Here we report hollow core fibres, of nested antiresonant design, with losses comparable or lower than achievable in solid glass fibres around technologically relevant wavelengths of 660, 850, and 1060 nm. Their lower than Rayleigh scattering loss in an air-guiding structure offers the potential for advances in quantum communications, data transmission, and laser power delivery.

scholarly journals Optical Fibres for Condition Monitoring of Railway Infrastructure—Encouraging Data Source or Errant Effort?

2020 ◽  
Vol 10 (17) ◽  
pp. 6016 ◽  
Author(s):  
Ivan Vidovic ◽  
Stefan Marschnig
Keyword(s):  
Rayleigh Scattering ◽  
Acoustic Vibration ◽  
Optical Fibres ◽  
Maintenance Planning ◽  
Root Cause ◽  
Railway Tracks ◽  
Railway Infrastructure ◽  
Vibration Sensing ◽  
Data Source ◽  
Asset Data

The condition of railway infrastructure is currently assessed by track recording cars, wayside equipment, onboard monitoring techniques and visual inspections. These data sources deliver valuable information for infrastructure managers on the asset’s condition but are mostly carried out in time-based intervals. This paper examines the potential of fibre optic cables, which are already installed in cable troughs alongside railway tracks, to monitor railway infrastructure conditions. The sensing technique, known as distributed acoustic/vibration sensing (DAS/DVS), relies on the effect of Rayleigh scattering and transforms the optical fibre into an array of “virtual microphones” in the thousands. This sensing method has the ability to be used over long distances and thus provide information about the events taking place in the proximity of the monitored asset in real-time. This study outlines the potential of DAS for the identification of different track conditions and isolated track defects. The results are linked to asset data of the infrastructure manager to identify the root cause of the detected signal anomalies and pattern. A methodology such as this allows for condition-based and component-specific maintenance planning and execution and avoids the installation of additional sensors. DAS can pave the way toward a permanent and holistic assessment of railway tracks.

Fluoride-glass-cladded optical fibres for mid-infra-red ray transmission

1981 ◽  
Vol 17 (17) ◽  
pp. 591 ◽  
Author(s):  
S. Mitachi ◽  
T. Miyashita ◽  
T. Kanamori
Keyword(s):  
Fluoride Glass ◽  
Optical Fibres ◽  
Infra Red

Fluoride Glass Optical Fibres

1990 ◽  
Author(s):  
P. W. France ◽  
M. G. Drexhage ◽  
J. M. Parker ◽  
M. W. Moore ◽  
S. F. Carter ◽  
...  
Keyword(s):  
Fluoride Glass ◽  
Optical Fibres

Strain and crack analysis within concrete members using distributed fibre optic sensors

2018 ◽  
Vol 18 (5-6) ◽  
pp. 1510-1526 ◽  
Author(s):  
Rafał Sieńko ◽  
Mariusz Zych ◽  
Łukasz Bednarski ◽  
Tomasz Howiacki
Keyword(s):  
Reinforced Concrete ◽  
Optical Fibre ◽  
Structural Damage ◽  
Rayleigh Scattering ◽  
Measurement Data ◽  
Sensor Technology ◽  
Optical Fibres ◽  
Structural Behaviour ◽  
Fibre Optics ◽  
Concrete Members

This article presents laboratory tests, with the purpose being to verify the suitability of standard optical fibres in a tight jacket for advanced strain analysis within concrete members. An optical reflectometer was used to enable the optical signal to be processed on the basis of the Rayleigh scattering phenomenon, so that strains and/or temperature changes were determined along the length of the measuring fibre. The measurements were carried out continuously in a geometrical sense (distributed measurements), with a spatial resolution starting from as fine as 5 mm. The arrangement of optical fibres inside the heterogeneous concrete medium and on its surface allowed for the identification and detailed analysis of local phenomena such as cracks. Remote and early location of structural damage with an estimation of its scale provides new opportunities for the monitoring of the structural health of reinforced concrete structures, facilitating the interpretation of its behaviour as well as failure risk management based on comprehensive and reliable measurement data. If traditional spot techniques are used, this approach is not possible. The aim of the initial studies was to analyse the strain distributions over compressed and tensioned measurement sections located on the surface of a cylindrical specimen of concrete. In the tests which followed, the reinforced concrete rod was eccentrically tensioned with fibre optics installed inside. Qualitative and quantitative verification of crack widths was made, with a narrow range up to 0.05 mm and a wider one to 0.30 mm. The results of the studies show very good accuracy of optical fibre sensor technology as a reference technique during the analysis of microcracks and narrow cracks, and moderate accuracy in the case of wider cracks. Despite using optical fibres in a tight jacket which mediates in strain transfer, the results obtained can be very suitable for the assessment of the structural condition of the member under consideration. It is also worth noting that the tests conducted indicate the effectiveness of distributed optical fibre technology for the analysis of concrete homogeneity and its structural behaviour within compressed areas, as it is possible to calculate strains over measuring bases that start from lengths as short as 5 mm.

Rayleigh Scattering From Multimode Optical Fibres At Very High Temperatures

1990 ◽  
Author(s):  
D. J. Booth ◽  
S. F. Collins ◽  
A. Shelamoff ◽  
J. C. Scott
Keyword(s):  
High Temperatures ◽  
Rayleigh Scattering ◽  
Optical Fibres ◽  
Very High

Optical studies of glass stability in fluoride glass systems: Intrinsic rayleigh scattering

1988 ◽  
Vol 102 (1-3) ◽  
pp. 295-301 ◽  
Author(s):  
J. Schroeder ◽  
V.G. Tsoukala ◽  
G.A. Floudas ◽  
D.A. Thompson
Keyword(s):  
Rayleigh Scattering ◽  
Fluoride Glass ◽  
Optical Studies ◽  
Glass Stability

Fusion splicing of heavy metal fluoride glass optical fibres

1989 ◽  
Vol 25 (18) ◽  
pp. 1214 ◽  
Author(s):  
B.B. Harbison ◽  
W.I. Roberts ◽  
I.D. Aggarwal
Keyword(s):  
Heavy Metal ◽  
Fluoride Glass ◽  
Metal Fluoride ◽  
Optical Fibres ◽  
Heavy Metal Fluoride

Fluoride glass optical fibres

1990 ◽  
Vol 124 (2-3) ◽  
pp. 278
Author(s):  
J.W. Fleming
Keyword(s):  
Fluoride Glass ◽  
Optical Fibres
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