| Project/Area Number |
60460123
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子材料工学
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| Research Institution | WASEDA UNIVERSITY |
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Principal Investigator |
OHKI Yoshimichi (1986) Waseda University, 理工学部, 教授 (70103611)
矢作 吉之助 (1985) 早稲田大学, 理工学部, 教授
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| Co-Investigator(Kenkyū-buntansha) |
NAGASAWA Kaya Waseda University, 理工学部, 助手 (20180474)
HAMA Yoshimasa Waseda University, 理工学研究所, 教授 (40063680)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1985: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Keywords | Optical Fibers / Pure Silica Glass / Optical Absorption Bands / Defects / ノン・ストイキオメトリ |
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| Research Abstract |
Various optical absorption bands are induced in <gamma> -ray irradiated pure-silica-glass. The cause of seven of these absorption bands, existing in the UV to near IR regions, were not understood. Using ESR and optical absorption experiments, we show that four of these bands can be explained by factors such as impurity content (Cl, OH groups), and nonstochiometry between Si and O in the glass. In the course of the investigation, we found that a fiber with good radiation resistance characteristics is not necessarily a high OH content fiber, as was previously believed.
In a number of fibers, the growth of radiation induced defects is different even though the impurity content of the fiber is basically the same. This rather unusual phenonena is caused by stoichiometric imbalance of the ppm order between oxygen and silicon. In oxygen excessive glass, peroxy radicals ( Si-O-O・ ) are formed from either oxygen molecules or other excess oxygen such as peroxy linkages. In oxygen deficient glass on the other hand, the 245nm absorption (caused by Si-Si Bonds ) is observed. Molecular orbital calculations show that in order for the Si-Si bond to be the cause of the 245nm absorption, the distance between the two Si atoms must be 3.08 A. This distance is very near the distance between Si and Si in a normal Si-O-Si bond, which is 3.10 A. These results indicate that the structure of silica glass used as the core in optical fibers is far more orderly than previously believed.
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