• Title, Summary, Keyword: Mid-Span Spectral Inversion (MSSI)

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Cross Phase Modulation Effects on 120 Gbps WDM Transmission Systems with Mid-Span Spectral Inversion for Compensation of Distorted Optical Pulse (광 펄스 왜곡의 보상을 위해 Mid-Span Spectral Inversion 기법을 채택한 120 Gbps WDM 시스템에서 채널간 상호 위상 변조 현상의 영향)

  • 이성렬;권순녀;이윤현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.7
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    • pp.741-749
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    • 2003
  • In this paper, we investigated the degree of compensation for WDM channel signal distortion due to chromatic dispersion, self phase modulation(SPM) and cross phase modulation(XPM). The considered system is 120 Gbps (3${\times}$40 Gbps) intensity modulation direct detection(IM/DD) WDM transmission system with path-averaged intensity approximation(PAIA) mid-span spectral inversion(MSSI) as compensation method. This system have highly nonlinear dispersion shifted fiber(HNL-DSF) as nonlinear medium in optical phase conjugator(OPC). We use 1 dB eye opening peralty(EOP) in order to evaluate the characteristics of compensation for distorted WDM channels. We confirmed that improvement of transmission distance and performance is achieved by MSSI method to distorted long-haul IM/DD WDM channels due to chromatic dispersion, SPM and XPM. And in the aspect of compensation for distorted pulse due to XPM, the MSSI method is effective to IM/DD WDM transmission system with high fiber dispersion coefficient.

Compensation of Distorted WDM signals due to Cross Phase Modulation Effects using Mid-Span Spectral Inversion (상호 위상 변조에 의해 왜곡된 WDM 신호의 Mid-Span Spectral Inversion을 이용한 보상)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.7 no.2
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    • pp.128-134
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    • 2003
  • In this paper, we investigated the degree of compensation for WDM channel signal distortion due to chromatic dispersion, self phase modulation (SPM) and cross phase modulation (XPM) as a function of transmission length using mid-span spectral inversion (MSSI) compensation method. The considered system is $3{\times}40$ Gbps intensity modulation direct detection (IM/DD) WDM transmission system. This system has highly nonlinear dispersion shifted fiber (HNL-DSF) as a nonlinear medium in optical phase conjugator (OPC). We confirmed that the transmission length is more increased by applying MSSI to distorted signal due to chromatic dispersion, SPM and XPM as dispersion coefficient of fiber becomes higher. And the compensation degree of distorted WDM channels due to chromatic dispersion, SPM and XPM becomes better stable as dispersion coefficient of fiber becomes higher.

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Characteristics of Compensation for WDM Transmission with Equally Spaced Channels using Mid-Span Spectral Inversion (채널 간격이 일정한 WDM 전송에서의 Mid-Span Spectral Inversion을 이용한 보상 특성)

  • 이성렬;임황빈
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.6
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    • pp.619-626
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    • 2004
  • In this paper, we investigated the compensation characteristics of distorted 16-channel WDM signal due to chromatic dispersion self phase modulation(SPM) and four-wave mixing(FWM). The bit rate and uniform frequency spacing of WDM channels are assumed to be 40 Gbps and 100 ㎓, respectively. The compensation method used in this approach is mid- span spectral inversion(MSSI), Highly-nonlinear dispersion shifted fiber(HNL-DSF) is used as a nonlinear medium of optical phase conjugator(On) in order to widely compensate WDM signal band. We confirmed that applying MSSI in WDM channels within special input power level compensates overall interferenced channels mainly due to FWM. But for long wavelength WDM channels having lower conjugated light power with respect to signal light power, compensation quality is deteriorated as dispersion coefficient of fiber becomes higher. Consequently, we confirmed that it is effective D apply MSSI with HNL-DSF as a nonlinear medium of OPC to WDM transmission link with relative small dispersion in order to compensate equally spaced WDM channels.

Mid-Span Spectral Inversion Technique in Lumped Dispersion Managed WDM Transmission Systems (집중형 분산 제어 WDM 전송 시스템에서 Mid-Span Spectral Inversion 기술)

  • Lee, Seong-Real
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.1A
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    • pp.7-15
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    • 2008
  • In this paper, it is investigated that the limitation due to the asymmetry of optical power with respect to optical phase conjugator(OPC) in mid-span spectral inversion(MSSI) for compensating optical signal distortion due to group velocity dispersion(GVD) and nonlinearities generated in fiber by combining with lumped dispersion management(DM) technique into MSSI. Two kinds of lumped DM configuration(configuration A and configuration B) are considered and compared each other in this research. Configuration A consists of two dispersion compensating fiber(DCF) span positioned after transmitter and before receiver, respectively. Configuration B consists of two dispersion compensating fiber(DCF) span positioned before and after OPC placed at middle of total transmission link, respectively. It is confirmed that the transmission performances are more improved by the configuration A combined with MSSI than configuration B. Also, it is confirmed that the best performance of overall channels are obtained by making net residual dispersion(NRD) to have positive value in self phase modulation(SPM)-limited WDM transmission systems, irrelevant to the configuration of DM.

Analysis of the Influence of Mutual Relation of Optical Pulse Frequency Chirp and Kerr Effect on the Mid-Span Spectral Inversion Methods for the Long-Haul Optical Transmission (광 펄스 주파수 첩과 Kerr 효과의 상호 관계가 장거리 광 전송을 위한 MSSI 보상 기법에 미치는 영향 분석)

  • 이성렬;이윤현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.9
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    • pp.898-906
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    • 2002
  • In this paper, we investigated the improvement degree of transmission distance of the various initial frequency chirped optical pulse with 5 dBm initial power dependence on the various bit rate and fiber dispersion coefficient, when MSSI(Mid-Span Spectral Inversion) with the optimal pump power condition is adopted for the compensation method for optical pulse distortion. And we analyzed the influence of mutual relation of optical pulse frequency chirp and Kerr effect on the MSSI methods for the long-haul optical transmission through the computer simulation. We found that the compensation degree of distorted optical pulse varies as a consequence of the variation of combined phase modulation of self phase modulation(Kerr effect) and initial frequency chirp parameter dependence on the fiber dispersion coefficient. And we found that, if the transmission bit rate is increased k times, the dispersion coefficient value of dispersion shift fiber is decreased $2^k$ times so as to be almost the same performance of the transmission system with k times lower bit rate.

Wideband Optical Phase Conjugator using HNL-DSF in WDM Systems with Path-Averaged Intensity Approximation Mid-Span Spectral Inversion (경로 평균 강도 근사 기법의 MSSI를 채택한 WDM 시스템에서 HNL-DSF를 갖는 광대역 광 위상 공액기)

  • Lee, Seong-Real;Lee, Yun-Hyun
    • Journal of Advanced Navigation Technology
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    • v.7 no.1
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    • pp.14-21
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    • 2003
  • We investigated the optimum pump light power compensating distorted WDM signal due to both chromatic dispersion and self phase modulation (SPM). The considered system is $3{\times}40$ Gbps intensity modulation direct detection (IM/DD) WDM transmission system with path-averaged intensity approximation (PAIA) mid-span spectral inversion (MSSI) as compensation method. This system have highly nonlinear dispersion shifted fiber (HNL-DSF) as nonlinear medium of optical phase conjugator (OPC) in the mid-way of total transmission line. We confirmed that HNL-DSF is an useful nonlinear medium in OPC for wideband WDM transmission, and the excellent compensation is obtained when the pump light power of HNL-DSF OPC was selected to equalize the conjugated light power into the second half fiber section with the input WDM signal light power depending on total transmission length. By this approach, it is verified the possibility to realize a long-haul high capacities WDM system by using PAIA MSSI compensation method, which have HNL-DSF OPC with optimal pump light power depending on transmission length.

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Mid-Span Spectral Inversion Technique with Optimal Parameters in 640 Gbps WDM Transmission System over NZ-DSF of 1,000 km (1,000 km의 NZ-DSF를 전송하는 640 Gbps WDM 시스템에서 최적 파라미터를 갖는 Mid-Span Spectral Inversion 기법)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.11 no.1
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    • pp.50-58
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    • 2007
  • In this paper, the optimum position of optical phase conjugator (OPC) and the optimal dispersion coefficients of fiber sections in $16{\times}40$ Gbps WDM system with non zero - dispersion shifted fiber (NZ-DSF) of 1,000 km are induced, in order to expand the availability of mid-span spectral inversion (MSSI) technique in long-haul multi-channel transmission systems. It is confirmed that the compensation degrees of overall WDM channels are more improved by applying the induced optimal parameters into WDM system than those in WDM system with the conventional MSSI. So it is expected that the proposed optimal parameters should alternate with the forming method of the symmetrical distributions of optical power and local dispersion with respect to OPC, which generate a serious problem in the applying OPC into multi-channels WDM system if it is not formed. It will be possible to realize the flexible system design by applying the methods proposed in this paper into the real WDM system with OPC.

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Wideband WDM Transmission through the Power Symmetry Method in the Mid-Span Spectral Inversion (Mid-Span Spectral Inversion을 이용한 광 펄스 왜곡의 보상에서 전력 대칭을 통한 광대역 WDM 전송)

  • 이성렬;이윤현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.7
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    • pp.1157-1166
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    • 2001
  • In this paper, we investigated the degree of compensation for optical pulse shape distortion due to both chromatic dispersion and SPM(self phase modulation) in high speed optical transmission system with dispersion shift fiber. We adopted the power symmetric MSSI(mid-span spectral inversion) as compensation method. We used EOP(eye-opening penalty) parameter in order to evaluate the compensation efficiency of distorted optical pulse. We evaluated input signal power range being able to maintain stable reception performance in the case of various chirp parameter of modulated optical pulse. And, in order to verify the applicable to wideband WDM system, we evaluated the wavelength range being able to maintain stable reception performance through the EOP calculation of various dispersion coefficient of first fiber D$\_$11/. We showed that proposed MSSI is effective compensation method to down chirped optical pulse transmission rather than up chirped optical pulse transmission in anomalous dispersion range. And we showed that this method have possibility of relative high power transmission and wideband transmission in WDM system.

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Characteristics of Compensation for Distorted Optical Pulse with Initial Frequency Chirp in 3 X 40 Gbps WDM Systems Adopted Mid-Span Spectral Inversion

  • Lee, Seong-Real;Lee, Yun-Hyun
    • Journal of electromagnetic engineering and science
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    • v.3 no.2
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    • pp.79-85
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    • 2003
  • In this paper, we investigated the degree of compensation for distorted optical pulse of wavelength division multiplexed(WDM) channel with initial frequency chirp generated in optical transmitter. The WDM channel signal distortion is due to chromatic dispersion, self phase modulation(SPM) and cross phase modulation(XPM) in fiber. The considered system is 3 ${\times}$ 40 Gbps intensity modulation direct detection(IM/DD) WDM transmission systems, which adopted mid-span spectral inversion(MSSI) as compensation method. We confirmed that the effect of initial frequency chirp on compensation for signal distortion due to a SPM is gradually decreased as a dispersion coefficient of fiber becomes gradually small. But, in the aspect of a compensation for signal distortion due to both SPM and XPM, the effect of initial frequency chirp on compensation is gradually decreased as a dispersion coefficient of fiber becomes gradually large.

Compensation Characteristics of Distorted Channels in 200 Gbps WDM Systems using Mid-Span Spectral Inversion Method (200 Gbps WDM 시스템에서 Mid-Span Spectral Inversion 기법을 이용한 채널 왜곡의 보상 특성)

  • 이성렬
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.8
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    • pp.845-854
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    • 2003
  • In this paper, the characteristics of compensation for WDM channel signal distortion due to both chromatic dispersion and Ken effect in 1,000 km 200 Gbps(5${\times}$40 Gbps) WDM systems was investigated. The WDM system has a path-averaged intensity approximation(PAIA) mid-span spectral inversion(MSSI) as a compensation method. This system has a highly nonlinear dispersion shifted fiber(HNL-DSF) optical phase conjugator(OPC) in the mid-way of transmission line. In order to evaluate the degree of compensation, 1 dB eye opening penalty(EOP), bit error rate(BER) characteristics and power penalty of 10$\^$-9/ BER are used. It is confirmed that HNL-DSF is an useful nonlinear medium in OPC fur wideband WDM system with PAIA MSSI and that the optimal compensation for WDM channel distortion is achieved by the selection of pump light power of OPC, which equalize the conjugated light power into the second half fiber section with the input WDM signal light power depending on total transmission length, dispersion coefficient of fiber, OPC pump light wavelength, conversion efficiency of WDM channel in OPC.