2001 Fiscal Year Final Research Report Summary
Study on all optical signal regeneration technology in ultrafast optical communication system
| Project/Area Number |
12305026
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | The University of Tokyo |
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Principal Investigator |
KIKUCHI Kazuro Research Center for Advanced Science and Technology, Professor, 先端科学技術研究センター, 教授 (50134458)
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| Co-Investigator(Kenkyū-buntansha) |
TAKUSHIMA Yuichi Research Center for Advanced Science and Technology, Associate Professor, 先端科学技術研究センター, 助教授 (10272585)
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| Project Period (FY) |
2000 – 2001
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| Keywords | all opticall signal regeneration / nonlinear optical device / Optical switch / WDM / OTDM |
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| Research Abstract |
All-optical nonlinear interferometric switches (NIS) are very attractive devices to realize the all optical 2R/3R function. The Mach-Zehnder interferometer (MZI) using semiconductor optical amplifiers and the nonlinear optical loop mirror (NOLM) using dispersion-shifted fibers are good candidates for practical NIS configurations.
When these NIS 's are periodically inserted in a long-distance transmission system using optical amplifiers, we can expect that the NIS's prevent the degradation of the SNR induced by the accumulation of the optical amplifier noise.
We derive a simple formula for calculating the SNR in the transmission system where NIS's are periodically inserted. Prom this formula, we clearly see that the SNR can be maintained at a certain value even after the signal traveling over an infinite distance. This formula also predicts that there exists a critical level of the optical amplifier noise. When the optical amplifier noise is larger than the critical level, the improvement of the SNR can no longer be achieved.
We also construct a NOLM composed of a 50-m highly-nonlinear dispersion-shifted fiber, and succeed in switching of 0.5-ps optical pulses. In addition, the polarization diversity scheme for the NOLM is demonstrated.
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