| Project/Area Number |
11650036
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied optics/Quantum optical engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
MATSUURA Yuji Tohoku University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (10241530)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAGI Mitsunobu Graduate School of Engineering, Tohoku University, Professor, 大学院・工学研究科, 教授 (90006263)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2000: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1999: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | Hollow fiber / YAG laser / Infrared fiber / Optical fiber / Laser machining |
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| Research Abstract |
Application of Q-switched Nd : YAG lasers emitting optical pulse width of 5-10 ns is rapidly expanding its area since the laser equipment has become smaller and cheaper recently. Common silica glass fibers, however, cannot effectively transmit Q-switch pulses with a peak power more than 1 MW because of the damage at the input end and the core induced by radiation of high-energy density pulses and nonlinear effect of silica glass. Therefore, the purpose of our research is to expand the application area of Q-switched Nd : YAG lasers which is currently limited by the above fact. Our final goal is to develop a delivery system based on hollow glass fibers which deliver optical pulses with more than 100 MW of peak power.
The following results were obtained in this research :
(1) Design and fabrication of polymer-coated hollow fibers by using a liquid-phase fabrication method.
To lower scattering losses for visible and near-infrared light, smoothness and uniformity of metal films coated on the inside of hollow fibers are improved. A silver film formed by a conventional mirror plating technique.. It was found that the smoothness and uniformity are greatly improved by keep the reaction temperature at constant by using a newly developed, water cooling system. Fibers fabricated using the new system showed low delivery losses specially for 2nd and 3rd harmonic pulses of Nd : YAG laser light.
(2) Development of input couplers and gas-introducing system
To suppress air-breakdown induced when radiating high-energy optical pulses, a input coupler which introduce inert gas to a hollow core region of fibers was designed and fabricated. This coupler enables delivery of Nd : YAG laser pulses with more than 10 MW of peak power.
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