| Presentation | 2017-08-31 Observation of eigen-mode propagation by selective mode excitation Yasuo Kokubun, Takuto Yamaguchi, Seiya Miura, |
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| PDF Download Page |  PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | LP mode is widely used to describe the light propagation in few mode fibers. Since an LP mode is a quasi-degenerate mode which is expressed by the linear combination of true eigen-modes (HE, EH, TE, and TM modes), however, the mode demultiplexing is difficult at the output end of few mode fibers and the MIMO-DSP is inevitable. To solve this problem, we proposed a novel mode division multiplexing using true eigen-modes. However, since the light propagation in an actual fiber is affected by some imperfections such as a bend, the elliptical deformation of core, twist, and so on, a discriminant analysis method of eigen-mode of actual few-mode fibers is required. Thus in this report, we observed the eigen-mode of actucal few-mode fibers from the near-field pattern at the output end of the fiber by varying the wavelength of light source. As the result, the true eigen-mode propagation was observed for step-index and graded-index single-core few-mode fibers while LP$_{11}$ modes were propagated as eigen-modes in 4LP-mode 12-core and 4LP-mode 19-core fibers. The elliptical deformation of these fibers was measured using an optical microscope, and the ellipticity were less than 4% for single-core, 12-core, and 19-core fibers. It can be concluded from these experimental results that the origin of the LP$_{11}$ mode propagation as the eigen-mode is not the elliptical deformation of core but other reasons such as the internal stress. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Mode division multiplexing / Few mode fiber / Eigen-mode / LP mode / Near-field pattern |
| Paper # | OCS2017-24 |
| Date of Issue | 2017-08-24 (OCS) |
| Conference Information | |
| Committee | OFT / OCS / LSJ |
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| Conference Date | 2017/8/31(2days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | Hokkaido Univ. |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | |
| Chair | Masayuki Shigematsu(Sumitomo Electric Industries) / Itsuro Morita(KDDI Research) |
| Vice Chair | |
| Secretary | (Furukawa Electric Industries) / (NTT) / (Sumitomo Electric Industries) |
| Assistant | Ikutaro Ogushi(NTT) / Katsuki Suematsu(Furukawa Electric Industries) |
| Paper Information | |
| Registration To | Technical Committee on Optical Fiber Technology / Technical Committee on Optical Communication Systems / The Laser Society of Japan |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Observation of eigen-mode propagation by selective mode excitation |
| Sub Title (in English) | |
| Keyword(1) | Mode division multiplexing |
| Keyword(2) | Few mode fiber |
| Keyword(3) | Eigen-mode |
| Keyword(4) | LP mode |
| Keyword(5) | Near-field pattern |
| 1st Author's Name | Yasuo Kokubun |
| 1st Author's Affiliation | Yokohama Natinal University(Yokohama Nat'l Univ.) |
| 2nd Author's Name | Takuto Yamaguchi |
| 2nd Author's Affiliation | Yokohama Natinal University(Yokohama Nat'l Univ.) |
| 3rd Author's Name | Seiya Miura |
| 3rd Author's Affiliation | Yokohama Natinal University(Yokohama Nat'l Univ.) |
| Date | 2017-08-31 |
| Paper # | OCS2017-24 |
| Volume (vol) | vol.117 |
| Number (no) | OCS-196 |
| Page | pp.pp.7-12(OCS), |
| #Pages | 6 |
| Date of Issue | 2017-08-24 (OCS) |