Infra-red optical loss increase for silica fibre in cable filled with water

Uesugi, Naoshi; Murakami, Yukio; Tanaka, C.; Ishida, Yukinori; Mitsunaga, Yutaka; Negishi, Y.; Uchida, Naoya

doi:10.1049/el:19830520

Cited by 40 publications

(5 citation statements)

References 2 publications

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“…Hydrogen Effects: Loss increases due to hydrogen effects in optical fibers were discovered by Japanese engineers in 1983 [22], [23], and this problem is very important, particularly in submarine optical fiber cables. Since these first reports in the fall 1983, active studies have been carried out throughout the world, and such effects are now well understood [24]- [27].…”

Section: Cable Technologymentioning

confidence: 99%

“…Loss increases in optical fibers due to hydrogen effects are caused by two different mechanisms: a) absorption due to molecular hydrogen which diffuses into interstices in silica-oxide network [22], [23], (interstitial molecular hydrogen absorption) (Fig. 4), and b) absorption due to chemical reaction of diffused hydrogen with reactive sites in glass to form, for example, -OH, [23], [28], [29] -H, and possibility some absorbing center in shorter wavelength [30] (absorption due to chemical reaction) (Fig.…”

Section: Cable Technologymentioning

confidence: 99%

“…4), and b) absorption due to chemical reaction of diffused hydrogen with reactive sites in glass to form, for example, -OH, [23], [28], [29] -H, and possibility some absorbing center in shorter wavelength [30] (absorption due to chemical reaction) (Fig. 5).…”

Section: Cable Technologymentioning

confidence: 99%

“…The longitudinal propagation of seawater into the cable which may result from breakage by fishing gear and so on, must be avoided, because a large quantity of hydrogen can be generated by electro-chemical reaction of seawater with metals in cables, and give arise to serious effects on transmission characteristics [22], [23]. Hence, blocking of water propagation by stuffing plastic compound in all cable interstices [8], and extensive experimental studies have been carried out on this approach [8].…”

Section: Cable Technologymentioning

confidence: 99%

See 3 more Smart Citations

Recent advances in submarine optical fiber cable transmission systems in Japan

Iwamoto

Fukinuki

1985

J. Lightwave Technol.

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Section: Cable Technologymentioning

confidence: 99%

Section: Cable Technologymentioning

confidence: 99%

Section: Cable Technologymentioning

confidence: 99%

Section: Cable Technologymentioning

confidence: 99%

See 2 more Smart Citations

Recent advances in submarine optical fiber cable transmission systems in Japan

Iwamoto

Fukinuki

1985

J. Lightwave Technol.

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“…However, even those fibers using high temperature polymer buffers suffer from ingression of water and hydrogen which increase attenuation and reduce the fatigue stress resistance. [1][2][3][4][5][6][7][8] Hermetic coatings were then developed to block water ingression and to delay hydrogen diffusion. The most common hermetic coating is a thin layer of carbon that is deposited during the pulling stage of the fiber manufacturing process.…”

Section: Introductionmentioning

confidence: 99%

Survivability of Optical Fiber for Harsh Environments

Ramos

Hawthorne

2008

All Days

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Today, optical-fiber systems are used in the oilfield for sensing and telemetry applications. The most commonly used downhole is the distributed temperature sensing (DTS) system which collects permanent real-time temperature well logs. These logs are extremely useful for real-time production allocation, heavy oil thermal recovery (e.g., steam-assisted gravity drainage, SAGD), steam-well management, and well-integrity monitoring.Unfortunately, optical fibers are not immune to degradation under downhole conditions. Hydrogen, present in the wells because of corrosion or other factors, can attack the optical-fiber components causing attenuation increase. This attenuation can have a negative effect on the performance of the system, such as decreasing accuracy or resolution. Understanding the process and the impact of this degradation is of great importance to the reliable operation of these optical-fiber systems.This article shows how a combination of controlled testing and modeling calculations can be used to provide an estimation of the attenuation increase expected from the fiber with time and downhole conditions.Test results for attenuation of optical fiber in hydrogen atmospheres and under downhole temperatures will be shown. The article also provides results from the testing of a new optical fiber that was designed to give a considerable improvement in resistance to hydrogen attack. These results give an order of magnitude improvement in comparison with commercially available optical fibers. Early field tests are consistent with the results of the study.

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Optical fiber loss increase due to hydrogen and long‐term loss stability for optical fiber cables

Noguchi

Shibata

Uesugi

et al. 1986

Electron Comm Jpn Pt II

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Recently, it has become clear that the long‐term loss of an optical fiber increases if the fiber is exposed to hydrogen. This phenomenon indicates that the loss in the optical fiber installed in a cable can increase if for some reason hydrogen is generated in the fiber cable. Therefore, this phenomenon is important for reliability design consideration. When the optical communication system with the 1.3 μm band is in actual use and the one with the 1.5 μm band is nearing its preparation for actual use, it is especially important to understand clearly the guarantee of long‐term reliability of an optical fiber cable and prevention of the effects of hydrogen. In this paper, the loss increase characteristics are formulated for optical fiber with germanium as an only dopant placed in a hydrogen atmosphere. The formulation is done from the results of increased temperature tests in hydrogen. From the formula, an allowable level of hydrogen pressure in the cable is calculated such that the loss increase of the fiber is kept below a specified value. It is also shown that the loss increase is sufficiently suppressed for practice by preventing water leakage into the cable.

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Infra-red optical loss increase for silica fibre in cable filled with water

Cited by 40 publications

References 2 publications

Recent advances in submarine optical fiber cable transmission systems in Japan

Recent advances in submarine optical fiber cable transmission systems in Japan

Survivability of Optical Fiber for Harsh Environments

Optical fiber loss increase due to hydrogen and long‐term loss stability for optical fiber cables

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