• Title/Summary/Keyword: 파장분할 다중화

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Architecture of time-division -division hybrid photonic ATM switch with large capacity (대용량 시분할-파장분할 하이브리드 광 ATM 스위치 구조)

  • 박기오;김광복;안상호;엄진섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.12
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    • pp.2828-2833
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    • 1997
  • In this paepr, we have proposed an enhanced TDM with WDM hybrid photonic switching architecture, which has much simpler configuration and requires less hard ware. the basic module consists of arrayed waveguide grating (AWG) for wavelength division, compressor and fiber delay lines for time division. When compared with other systems, we proved that the proposed switch is suitable for large capacity photonic switching system due to less complexity and lower cost in implementation than the previous ones.

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Performance Analysis of the Dynamic Minislot reservation Protocol in Single-hop WDM Networks (단일-홉 파장분할 다중화 통신망에서 동적 미니슬롯 예약 프로토콜의 성능분석)

  • Jeong, Kil-Hyun;Lee, Jong-Kyu
    • Journal of KIISE:Information Networking
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    • v.29 no.3
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    • pp.205-215
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    • 2002
  • In this paper the Dynamic Minislot Reservation Protocol(DMRP) in which the control channel is divided into contention-less and contention minislots in order to reduce re-transmission probability in multicasting is proposed. In the network, earth node has two pairs of transceivers. A transceiver consisting of a fixed transmitter and a fixed receiver is used to control packet registration and the other transceiver is used to transmit data. Two types f transceivers for data transmission are considered : one is FT-TR(Fixed Transmitter-Tunable Receiver) and the other is TT-TR(Tunable Transmitter-Tunable Receiver). In the analysis, FT-TR and TT-TR single-hop passive star networks are compared. As results, we conclude that the DMRP protocol with dynamically divided control channel has improved the system performance such as throughput and system delay regardless of traffic type or network structure.

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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An Adaptive Distributed Wavelength Routing Algorithm in WDM Networks (파장분할 다중화 (WDM) 망을 위한 적응 분산 파장 라우팅 알고리즘)

  • 이쌍수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9A
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    • pp.1395-1404
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    • 2000
  • In this paper, we propose a heuristic wavelength routing algorithm for IP datagrams in WDM (Wavelength-Division Multiplexing) networks which operates in a distributed manner, while most previous works have focused centralized algorithms. We first present an efficient construction method for a loose virtual topology with a connectivity property, which reserves a few wavelength to cope with dynamic traffic demands properly. This connectivity property assures that data from any source node could reach any destination node by hopping one or multiple lightpaths. We then develop a high-speed distributed wavelength routing algorithm adaptive to dynamic traffic demands by using such a loose virtual topology and derive the general bounds on average utilization in the distributed wavelength routing algorithms. Finally, we show that the performance of the proposed algorithms is better than that of the FSP(Fixed Shortest-Path) wavelength routing algorithms through simulation using the NSFNET[1] and a dynamic hot-spot traffic model, and that the algorithms is a good candidate in distributed WDM networks in terms of the blocking performance, the control traffic overhead, and the computation complexity.

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The effect comparison using saturation tone signals for optical wavelength division multiplexing communications (32 채널 파장분할다중화 광통신 전송에서 이득포화 광신호 영향 비교)

  • Choi, Bo-Hun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.8
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    • pp.2037-2042
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    • 2014
  • Three methods for gain saturation tone application were compared for optical wavelength division multiplexing transmission using more than 32 channels. The methods are to use high power distributed feedback laser diodes, to use amplified light sources, and lastly to use one saturation tone and several WDM light sources. 1532.3 nm, 1545.7 nm, and 1558.2 nm for the wavelength dependency of the saturation tone were also compared. As a result, the effect of amplified spontaneous emission noise caused by an amplifier was very slight. long wavelength for a saturation tone caused 1 dB gain reduction and its reason was analyzed.

Optical cross-connects based on a WDM MUX/DEMUX pair and tunable fiber Bragg gratings (한 쌍의 파장 다중화기/역다중화기와 파장가변 광섬유 브래그 격자를 이용한 광 크로스-커넥트)

  • 김정호;정재훈;김성철;이병호
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.02a
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    • pp.78-79
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    • 2000
  • 재구성이 가능한 광 크로스-커넥트(optical cross connect)는 전광 네트워크를 구성하기 위한 핵심소자 중의 하나이다. 일반적인 구조의 파장분배기는 공간분할 스위치(space division switch)를 두 쌍의 파장 다중화기(multiplexer)와 역다중화기(demultiplexer)의 가운데에 삽입하여 구현된다$^{(1)}$ . 최근에, 광섬유 브래그 격자와 광스위치 쌍을 직렬 연결하여 재구성이 가능한 광 크로스-커넥트가 제안되었다$^{(2)}$ . 그러나, 이 구조는 광신호에 따라 광섬유 브래그 격자에 반사되면서 겪는 광스위치에 의한 삽입손실이 다르다는 문제점이 있다. 이러한 문제를 해결하기 위하여 본 논문에서는 한 쌍의 파장 다중화기/역다중화기와 파장가변 광섬유 브래그 격자를 이용한 새로운 구조의 광 크로스-커넥트를 제안하고자 한다. 또한, 제안된 구조는 일반적인 구조의 파장분배기에 비해 파장 다중화기/역다중화기의 개수를 반으로 줄일 수 있는 장점이 있다. (중략)

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All-fiber dynamic add-drop multiplexer based on acousto-optic interaction (음향광학 효과를 이용한 전광섬유 동적 파장가감기)

  • 박희수;송광용;윤석현;김병윤
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.52-53
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    • 2002
  • 파장분할 다중화 광통신 선로 상에서, 특정 파장 채널을 임의로 선택하여 분리/첨가 할 수 있는 동적파장가감기(wavelength-division dynamic optical add-drop multiplexer)는 광 네트워크의 효율을 높이는데 핵심 소자라 할 수 있다. 지난 수년간 개발된 수많은 기술들 중에서, LiNbO$_3$ 광도파로 음향광학소자(acousto-optic tunable filter: AOTF)는 몇 가지의 특징적인 장점들을 보여줬는데, 예를 들면 넓은 영역의 파장 선택성, 짧은 스위칭 시간, 다중 채널 동작 가능성 등이다. (중략)

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The Optical Filtering Effect of a RSOA-based Broadband Light Source in a Bidirectional WDM-PON System (파장분할 다중화 수동광 네트워크에서 적용된 반사형 반도체 증폭기 기반의 광역선폭 광원의 광필터 특성 의존성)

  • Choi, Bo-Hun
    • Korean Journal of Optics and Photonics
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    • v.22 no.3
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    • pp.122-128
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    • 2011
  • The AWG-filtering effect was investigated on a bidirectional 100-GHz-channel-spacing WDM-PON link using spectrum-sliced and RSOA-amplified light sources for downstream signals and a wavelength reuse technique for upstream signals. Signal performances of three different filtering AWGs, including Gaussian, trapezoidal, and rectangular types, were compared on link transmission with fiber nonlinear effects. As an extinction ratio of a downstream signal varied, the effect for both directional signals was analyzed and optimized. It was found that there was an optimal pass bandwidth of an AWG for the balance between relative intensity noise decrement and cross phase modulation noise increment as the bandwidth got wider.

Fabrication of an Optical Fiber Amplifier Using Long-period Fiber Gratings Formed by Periodically Arrayed Metal Wire (금속선의 주기적 배열로 유도된 장주기 격자를 이용한 이득 평탄화된 광섬유 증폭기 제작)

  • Sohn, Kyung-Rak;Hwang, Woong;Shim, June-Hwan
    • Journal of Navigation and Port Research
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    • v.31 no.10
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    • pp.833-837
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    • 2007
  • In this study, we have fabricated a gain flattened erbium-doped optical fiber amplifier. Gain flattening filters were realized by the strain-induced long period fiber gratings, which are made of periodically arrayed metal wires. Using the filter of $550{\mu}m$ period, spontaneous emission amplified at C-band wavelength by a 980nm pumping laser was flattened within 1dB of gain ripple. The performance of the simultaneous multi channel amplification was measured using a fabry-perot laser diode. Amplification ratio was above 20dB. This amplifier can be applied to the long distance transmission system based on a wavelength division multiplexing for boosting an attenuated signal.