| DOI | Resolve DOI: https://doi.org/10.1117/12.2220789 |
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| Author | Search for: Mihailov, Stephen J.1; Search for: Grobnic, Dan1; Search for: Walker, Robert B.; Search for: Hnatovsky, Cyril A.1; Search for: Ding, Huimin1; Search for: Coulas, David1; Search for: Lu, Ping1 |
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| Affiliation | - National Research Council of Canada. Security and Disruptive Technologies
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| Format | Text, Article |
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| Conference | SPIE Commercial + Scientific Sensing and Imaging, April 18-21, 2016, Baltimore, Maryland, United States |
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| Subject | fiber optic sensor; fiber Bragg grating; femtosecond laser machining; photosensitivity |
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| Abstract | Fiber Bragg gratings (FBG) arrays in silica based optical fibers are increasingly used in applications involving system monitoring in extreme high temperature environments. Where operational temperatures are < 600 °C, traditional UVlaser inscribed FBGs are not appropriate since the induced Type I index change is erased. Instead two competing FBG technologies exist: 1) regenerative FBGs resulting from high temperature annealing of a UV-laser written grating in a hydrogen loaded fiber and 2) FBGs written with femtosecond infrared pulse duration radiation (fs-IR), either using the point-by-point method or using the phase mask approach. Regenerative gratings possess low reflectivity and are cumbersome to produce, requiring high temperature processing in an oxygen free environment. Multiple pulse Type II femtosecond IR laser induced gratings made with a phase mask, while having very good thermal stability, also tend to have high insertion loss (~ 1dB/grating) limiting the number of gratings that can be concatenated in a sensor array. Recently it has been shown that during multiple pulse type II thermally stable fs-IR FBG production, two competing process occur: an initial induced fs-IR type I FBG followed by a thermally stable high insertion loss type II FBG. In this paper, we show that if only a type I FBG is written using type II intensity conditions but limited numbers of pulses and then annealed above 600 °C, the process results in a type II grating that is stable up to 1000°C with very low insertion loss ideal for an FBG sensor array. |
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| Publication date | 2016-05-12 |
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| Publisher | SPIE |
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| In | |
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| Series | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 23000246 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | b08a2003-4584-42a0-941f-8508e8960a8d |
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| Record created | 2016-06-28 |
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| Record modified | 2020-03-16 |
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