• Title/Summary/Keyword: power penalty

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Fabrication and characterization of XPM based wavelength converter module with monolithically integrated SOA's (SOA 집적 XPM형 파장변환기 모듈 제작 및 특성)

  • 김종회;김현수;심은덕;백용순;김강호;권오기;엄용성;윤호경;오광룡
    • Korean Journal of Optics and Photonics
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    • v.14 no.5
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    • pp.509-514
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    • 2003
  • Mach-Zehnder interferometric wavelength converters with monolithically integrated semiconductor optical amplifiers (SOA's) have been fabricated and characteristics of wavelength conversion at 10 Gb/s have been investigated for wavelength span of 40 nm. The devices have been achieved by using a butt-joint combination of buried ridge structure type SOA's and passive waveguides. In the integration, a new method has been applied that removes p+InP cladding layer leading to high propagation loss and forms simultaneously the current blocking and the cladding layer using undoped InP. The module packaging has been achieved by using a titled fiber array for effective coupling into the tilted waveguide in the wavelength converter. Using the module, wavelength conversion with power penalty lower than 1 ㏈ at 10 Gb/s has been demonstrated for wavelength span of 40 nm. In addition, it is show that the module can provide 2R (re-amplification, re-shaping) operation by demonstrating the conversion with the negative penalty.

Effective Compensation of the Distorted 1.12 Tbps WDM Signals Using Optimization of Total Dispersion

  • Lee, Seong-Real
    • Journal of information and communication convergence engineering
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    • v.5 no.4
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    • pp.377-381
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    • 2007
  • Nonlinear effects and chromatic dispersion are the main causes of pulse degradation in high bit-rate WDM transmission systems and several architectures have been proposed to compensate them by means of optical phase conjugation. In this paper, a new method to exploit an optical phase conjugator (OPC) for nonlinearity and dispersion cancellation is disclosed. The proposed method is using optimal total dispersion of each fiber sections and it is simpler than those previously described in literature. Power penalty between WDM channels and the maximum launch power in $28{\times}40$ Gbps WDM transmission system designed by optimal total dispersion are more decreased and more increased than those in the conventional WDM transmission system with OPC, respectively. Furthermore, optimal total dispersion proposed in this research should provide the flexible design of WDM system, which less depends on OPC position.

Optimal Power Flow Study by The Newton's Method (뉴톤법에 의한 최적전력 조류계산)

  • Hwang, Kab-Ju
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.173-178
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    • 1989
  • Optimal Power Flow (OPF) solution by the Newton's method provides a reliable and robust method to classical OPF problems. The major challenge in algorithm development is to identify the binding inequalities efficiently. This paper propose a simple strategy to identify the binding set. From the mechanism of penalty shifting with soft penalty in trial iteration, a active binding sit is identified automatically. This paper also suggests a technique to solve the linear system whore coefficients are presented by the matrix. This implementation is highly efficient for sparsity programming. Case study for 3,5,14,118,190 bus and practrical KEPCO 305 bus system are performed as well.

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Functional Relation Between Signal Distortion and a Figure of Merit for Nonlinear Process in Dispersion-managed Optical Transmission

  • Kim, Sungman
    • Journal of the Optical Society of Korea
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    • v.16 no.2
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    • pp.95-100
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    • 2012
  • We show that the minimum EOP (eye-opening penalty) obtained by tunable dispersion compensation is a function of a figure of merit for a nonlinear process, $I_0L_{eff}$, where $I_0$ is the optical intensity and $L_{eff}$ is the effective length of the interaction region. Using this rule, we do not need to conduct nonlinear simulations in all the cases of signal power and transmission length to obtain the signal distortion in dispersion-managed optical transmission. Instead, we need to conduct a simulation in only one case of a signal power and find the functional relation, and then we can obtain the values of the signal distortion in other cases using the discovered functional relation. This technique can reduce the number of nonlinear simulations to less than 10%.

Reduction of the Power Penalty Induced by Low-Frequency Tone Using Variable Decision Threshold Technique

  • Lee, Chang-Hee;Kim, Sung-Man;Baik, Jin-Serk;Park, Kun-Youl
    • Journal of the Optical Society of Korea
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    • v.6 no.3
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    • pp.105-107
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    • 2002
  • We propose 'variable decision threshold technique' to decrease the power penalty induced by low-frequency tones. The proposed scheme uses a simple low-speed receiver to change the decision threshold of the optical receiver according to the low-frequency tones. We demonstrate the proposed method at 2.5 Gb/s.

Optimal Power Flow Study by The Newton's Method (뉴톤법에 의한 최적전력 조류계산의 개선)

  • Hwang, Kab-Ju
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.3
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    • pp.223-231
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    • 1990
  • Optimal Power Flow (OPF) solution by the Newton's method provides a reliable and robust method to classical OPF problems. The major challenge in algorithm development is to identify the binding inequalities efficiently. This paper proposes a simple strategy to identify the binding set. From the mechanism of penalty shifting with soft penalty in trial iteration, an active binding set is identidied automatically. This paper also suggests a technique to solve the linear system whose coefficients are presented in the matrix from. This implementation is highly efficient for sparsity programming. Case studies for 3, 5, 14, 118 bus and practical TPC-190, KEPCO-306 bus systems are performed as well.

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Performance Improvements through Controling Residual Dispersion Per Span in WDM Transmission Links with Zero Net Residual Dispersion (전체 잉여 분산이 영인 WDM 전송 링크에서 광 중계 거리 당 잉여 분산 제어를 통한 성능 향상)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.13 no.5
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    • pp.656-661
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    • 2009
  • High-quality transmission of $24{\times}40$ Gbps WDM signals obtained through controling residual dispersion per span (RDPS) in optical transmission links with zero net residual dispersion (NRD) of inline dispersion management (DM) of optical transmission links is researched. It is confirmed that RDPS values, which is improving system performance, depends on launch power of WDM channels, but optimal RDPS, which can simultaneously improve WDM signals with relative wide launch power ranges, becomes to be 210~230 ps/nm. Also, it is shown that effective launch power range that making eye opening penalty (EOP) of worst channel to below 1 dB is more increased as RDPS is more increased.

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Analysis of Infrared Wireless Indoor Communication Link with a Source on the Wall (벽면에 광소스가 위치하는 경우의 실내 무선 광링크 분석)

  • Ji, Yun-Gyu
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.2
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    • pp.46-54
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    • 2000
  • Because the installation of the optical cables in rooms is difficult, we can terminate the optical cable at the main enterence and use infrared wireless communications in the room. In this paper, we calculate the impulse response of the infrared wireless communication link and the optical power penalty due to multipath effect up to the third reflections with the source on the sidewall. We can locate the optical sources on the sidewall without problem because of relative large power reflected from the ceiling and sidewalls once. And the optical power penalty due to multipath effect can be neglected at the speed of 2 Mb/s.

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Performance of long-haul optical fiber commumication system using optical amplifiers with post amplifier loss (후치 증폭기 손실을 갖는 광섬유 증폭기를 사용한 장거리 광통신 시스템의 성능형가)

  • 이무도;이호준;이화용
    • Korean Journal of Optics and Photonics
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    • v.5 no.2
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    • pp.326-332
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    • 1994
  • Performance of soliton based long-haul optical communication system with in-line optical amplifier repeaters are evaluated numerically. To reduce the optical amplifier noise, the amplifier gain is increased and the post amplifier loss is included. By theoretical calculation with 1480 nm co propagating pump, 7 dB amplifier gain and operating the amplifier 1 dB in compression, the spontaneous emission factor can be reduced from 2.37 to 1.45 by increasing the pump power from 3.71 to 11.53 mW and increasing the post amplifier loss from 0 to 10 dB. Then, power penalty can be reduced from 4.09 to 1.20 dB for 8,000'km transmission and the maximum transmission distance is 14,890 km. ,890 km.

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Theoretical Investigation of First-order and Second-order Polarization-mode Dispersion Tolerance on Various Modulation Formats in 40 Gb/s Transmission Systems with FEC Coding

  • Jang, Ho-Deok;Kim, Kyoung-Soo;Lee, Jae-Hoon;Jeong, Ji-Chai
    • Journal of the Optical Society of Korea
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    • v.13 no.2
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    • pp.227-233
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    • 2009
  • We investigated the polarization-mode dispersion (PMD) tolerance for 40Gb/s non-return to zero (NRZ), duobinary NRZ, return to zero (RZ), carrier-suppressed RZ (CS-RZ), and duobinary-carrier-suppressed RZ (DCS-RZ) modulation formats with a forward error correction (FEC) coding. The power penalty has been calculated as a measure of the system performance due to PMD. After comparison of the PMD tolerance of various modulation formats, our results suggest that RZ signals have the best tolerance against the effect of first-order PMD only. The duobinary NRZ modulation format is most resilient to PMD when both first- and second-order PMD are considered. However, the duobinary NRZ modulation format is the most sensitive to the incident angle of the input signal to a fiber axis in the presence of first- and second-order PMD, leading to incident angle-dependent power penalty. The coding gain by FEC can cope with the power penalties induced by first- and second-order PMD up to a DGD value of 16ps.