1998 Fiscal Year Final Research Report Summary
The spot-size contraction technology for single-mode fibers and its applicaions
| Project/Area Number |
09450148
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
情報通信工学
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| Research Institution | Utsunomiya University |
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Principal Investigator |
SHIRAISHI Kazuo Faculty of Engineering, Professor, 工学部, 教授 (90134056)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUMURA Kazuhito Utsunomiya University, Faculty of Eng., Professor, 工学部, 教授 (70005297)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Opfical communication / Optical fiber / spot size / single-mode fiber / splicing / dispersion-compensated fiber / splice loss / mode |
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| Research Abstract |
The research has successfully finished. We find and experimentally verified an effective method to reduce modal-field diameter in single-mode fibers. The method utilizes a quarter-pitch length of a parabolic-index fiber having a high focusing parameter. We had experimentally confirmed that modal-field diameter of a standard single-mode fiber at the wavelength 1.55 mum has been reduced from 10.4 mum to 5.8 mum by use of the tip. As the result, we could reduced splicing losses between the standard single-mode fiber and a dispersion-compensated fiber that has a small spot diameter. The direct splicing loss, 2.3 dB, has been reduced to be 0.3 dB by making use of the tip.
In the research, we also developed a technique to cleave graded-index fibers with a precise length. We combined a set of micro positioners and amicroscope with a commercially-available fiber cleaver, As the result, the error in length has becomes less than 10 mum. A modified method utilizing two graded-index fibers having different focusing parameters was also proposed. The cascade configuration offers us variation of reduction ratios by combining two kinds of graded-index-fiber chips.
Technologies developed in the research promise low-loss coupling between standard single-mode fibers and various waveguides, such as dispersion compensated fibers, erbium-doped fibers, and planar waveguides.
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