• Title/Summary/Keyword: 광섬유 결합

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Characteristics of fiber-optic current sensors using perpendicular coil formers (수직원형틀을 이용한 광섬유전류센서의 동작특성)

  • 이명래;이용희;김만식
    • Korean Journal of Optics and Photonics
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    • v.7 no.4
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    • pp.419-427
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    • 1996
  • Thermally-stabilized fiber-optic current sensors are proposed and demonstrated. The sensor head is made of two coil formers combined perpendicularly. In this sensor head, bending-induced birefringences can be reduced to the level much smaller than those of the single former type because the eigen-axes of the two perpendicular coil formers are made orthogonal to each other. Moreover, thermal variation of the birefringence is also expected to be minimized by the orthogonality of the two polarization eigen-axes. We changed the temperature slowly in the range of 20~45$^{\circ}C$ during 100 minutes. The overall linearity of the sensor is better than 1.2% in the range of 0~1000A. The long-term fluctuation of the sensor is less than 1% when measured for 3 hours at 500A and room temperature. Two orthogonally-polarized laser diodes are combined together to make the incident beam unpolarized. In the signal processing, the signals are separated by two parts and normalized respectively, which minimize the efects of optical fluctuations coming from sources, connectors, etc.

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Grating-Assisted Codirectional Coupler Filter Using an Electro-Optic Polymer (전기광학 폴리머를 이용한 격자 보조 동방향 결합기형 필터)

  • 안세원;신상영
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.02a
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    • pp.138-139
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    • 2000
  • 최근 광섬유의 전송 용량을 효율적으로 극대화하기 위한 방안으로서 파장 분할 다중화 (WDM: Wavelength Division Multiplexing) 방식의 광통신 시스템이 제안되어 사용되고 있다. WDM 시스템에서는 각 채널 (channel) 마다 각기 다른 파장의 광신호가 할당되어 있기 때문에, 여러 파장이 다중화된 광신호에서 원하는 파장의 광신호를 선택하기 위해서는 파장 선택 필터 (wavelength selective filter) 가 필요하다. 격자 보조 동방향 결합기 (GACC: Grating-Assisted Codirectional Coupler) 는 전파 상수(propagation constant) 가 서로 다른 두 도파로 사이에서의 광파워 교환이 파장에 의존하는 특성을 가지고 있기 때문에 WDM 시스템에 응용될 파장 선택 필터로서 많은 연구가 되어 왔다$^{(1),(2)}$ . (중략)

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All-Fiber Microwave Signal Processing Device with Z-Shaped Double Coupler Optical Resonator (Z형 쌍-결합기 광 공진기를 이용한 광섬유 마이크로파 신호처리)

  • 이동욱
    • Proceedings of the Optical Society of Korea Conference
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    • 1999.08a
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    • pp.116-117
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    • 1999
  • Optical fiber networks for microwave signal processing have been investigation . Theoretical and experimental results are presented in Z-shaped Double-Coupler Optical Resonator. The use of Mason's rule to calculate transfer functions greatly simplified the analysis in our model. A good comparison between modelling and experiment is presented.

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