共查询到20条相似文献,搜索用时 10 毫秒
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We derive an explicit autocorrelation function (ACF) formula of state of polarization for a fiber transmission system with polarization mode dispersion (PMD) and polarization dependent loss (PDL), which is found to agree well with Monte Carlo simulation. Then we use the new ACF to investigate the combined effect of PMD and PDL on the polarization multiplexed scheme. We find the performance of the polarization multiplexed scheme can be deteriorated more severely than the case without PDL. 相似文献
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Xiaoguang Zhang Xuan Weng Feng Tian Wenbo Zhang Lixia Xi Guangyong Zhang 《Optics Communications》2011,284(18):4156-4160
This paper reports the DSP-based prototype compensator we have made to compensate the polarization mode dispersion (PMD) in fibers. It was tested in one channel of a 40 × 43-Gb/s DWDM DQPSK system, which is the commercial product line, either in the back-to-back case by using a PMD emulator, or in a 1200-km transmission testbed. The prototype showed a good performance under the tests of fast SOP and PSP rotation, DGD jump variation, and moderate knock on the testbed in a period as long as 12 h. 相似文献
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在高速相干光通信系统中,完全使用电子色散补偿时会引入均衡增强相位噪声.本文提出在已有10Gbit/s光纤通信链路上使用电子色散补偿来补偿残留色散的混合色散补偿方案,实现了特定通道100Gbit/s以上高速数据传输.使用虚拟光学仪器软件仿真了在112Gbit/s相干光通信系统中,分别采用有限脉冲响应均衡器和重叠频域均衡器对现有光纤信道进行残留色散补偿后的系统性能.仿真结果表明:相同的抽头长度下,有限脉冲响应均衡器相比重叠频域均衡器有更好的残留色散补偿能力,并且有限脉冲响应均衡器均衡性能更稳定而且计算复杂度更低.因而,有限脉冲响应均衡器相较于重叠频域均衡器更适于混合色散补偿. 相似文献
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High-speed polarization mode dispersion compensation in a 43-Gb/s RZ-DQPSK transmission system over 1200 km of standard single-mode fibre 下载免费PDF全文
This paper reports that the designed optical polarization mode dispersion compensator shows a good performance under the real-time variation of differential group delay, state of polarization and principal state of polarization in a (40 × 43)-Gb/s dense-wavelength-multiplexing, 1200-km enhanced return-to-zero differential-quadrature-phase-shift-keying (RZ-DQPSK) system. The polarization mode dispersion tolerance of the system is improved by 26 ps using the optical polarization mode dispersion compensator. The short and long time stabilities are tested with the bit error ratio recorded.vspace1mm 相似文献
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Transmission performance of 10-Gb/s DPSK WDM signals due to phase-error and four-wave mixing in SOAs
Sub Hur 《Optics Communications》2009,282(5):824-829
We present a complete dynamic model of semiconductor optical amplifiers (SOAs) including the inter-channel four-wave mixing (FWM). The model has been implemented using the time-dependent transfer matrix method (TMM) and applying the discretization scheme in both the spatial and spectral domains. In SOA-based wavelength division multiplexing transmission systems using 10-Gb/s differential phase shift keyed (DPSK) signals, the system performance due to the SOA-induced phase-error and the FWM effect has been analyzed. By the injection of a reservoir channel into SOAs, the transmission performance of non-return-to-zero (NRZ) DPSK signals can be improved through the phase-error reduction. Both the NRZ-DPSK and return-to-zero (RZ) DPSK signals are found to be suffered from the FWM-induced crosstalk. The overall nonlinear tolerance of RZ-DPSK is shown to be better than that of NRZ-DPSK. 相似文献
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We propose a novel modulation format of 50% RZ polarization interleaved multiplexing DQPSK for high-speed self-homodyne receiving systems. The proposed modulation format enables excellent tolerance of chromatic dispersion and polarization crosstalk. In self-homodyne receiving systems, the proposed format can reduce the cost of adaptive equalization module. It has potential applications in long-reach self-homodyne optical communication systems. 相似文献
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The phase error induced crosstalk within arrayed waveguide gratings (AWG) have been investigated theoretically as well as
simulation. For WDM system, a crosstalk level of −21.9 dB causes a power penalty of 1 dB for 64 channels and less than 0.5 dB
for 16 channels and 32 channels, respectively. For crosstalk level of −30 dB and below, the power penalty is negligible. Crosstalk
due to phase error also causes higher power penalty at higher bit rate. Bit rate of 10, 20 and 40 Gbits/s causes power penalty
of 1 dB with crosstalk level of −41.5, −46.25 and −49 dB, respectively. 相似文献
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Mohammad Ghanbarisabagh 《Optik》2013,124(24):6642-6646
This paper uses a Recursive Least Squares-Time Domain Equalizer (RLS-TEQ) to reduce the Cyclic Prefix (CP) length in Direct-Detection Optical Orthogonal Frequency Division Multiplexing (O-OFDM) transmission over 2400 km of Standard Single Mode Fiber (SSMF). The RLS-TEQ can cancel the residual Inter Symbol Interference (ISI) caused by both the Group Velocity Dispersion (GVD) and the CP length being shorter than the Channel Impulse Response (CIR). Using RLS-TEQ reduces size of the CP, and consequently leading to system performance improvement. 相似文献
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Sim Ngee Thiam 《Optik》2007,118(11):507-514
This paper presents a model that described the process of inter-influence between cross phase modulation (XPM) and polarization effects such as polarization mode dispersion (PMD) and polarization dependant loss (PDL) in an optical fiber communication system. Previous papers have discussed PMD-PDL and PMD-XPM effects in separate models, but in this work we developed a model that is capable of characterizing and evaluating PMD, PDL and XPM simultaneously. From the model, we found that PMD and PDL can be affected by XPM. The presence of XPM changed the vector directions of PMD and PDL in Stokes space. 相似文献
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C. C. Hiew H. T. Chuah H. A. Abdul-Rashid F. M. Abbou S. P. Majumder 《Fiber and Integrated Optics》2005,24(5):457-470
The impact of a post-OTDM-demultiplexing optical filter on the performance of dense on-off keying (OOK) optical time division multiplexing (OTDM)—wavelength division multiplexing (WDM) systems was studied. For return-to-zero (RZ) modulation, it was found that the additional filter working in a double-tier filter configuration did not offer any significant improvements to performance when the signal pulse width is optimized. Improvements generally increase only when the signal pulse width deviates from its optimal value and only for low spectral densities. For ideal non-return-to-zero (NRZ) modulation, however, significant improvements of around 1 dB are obtained using the double-tier configuration over a large range of spectral densities. 相似文献
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In this paper, the impact of second-order dispersion (2OD), third-order dispersion (3OD) and modulation frequency over stimulated Raman scattering (SRS)- and cross-phase modulation (XPM)-induced crosstalk in sub-carrier-multiplexed (SCM) wavelength division multiplexed (WDM) transmission link has been analyzed. It has been observed that there is significant effect of 2OD, 3OD and modulation frequency on the SRS- and XPM-induced crosstalk in a SCM-WDM transmission link. Here the results for SRS- and XPM-induced crosstalk have been reported with independent and combined higher-order dispersion. It has been observed that XPM-induced crosstalk lies between [−52.8 to −45.3] and [−94.7 to −78.6] dB in the presence of 2OD and 3OD respectively for modulation frequencies varied from 500 MHz to 2.0 GHz, while it is in the range of [−94.4 to −84] and [−128.5 to −117] dB when both SRS and XPM are taken into consideration. 相似文献
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J.M. Chavez Boggio E.A.M. Fagotto M.E. Marhic F.A. Callegari H.L. Fragnito 《Optics Communications》2007,280(2):468-471
We report on the amplification of 12 × 10 Gb/s wavelength-division-multiplexed signals by a double-pumped fiber optic parametric amplifier (2P-FOPA). A gain of 10 dB is obtained using a 4.3 km-long conventional dispersion shifted fiber (DSF) as nonlinear medium. Our spectra show negligible generation of spurious FWM products, and we attribute this to the small variations of the zero-dispersion wavelength of the DSF. The 2P-FOPA performance is assessed through Q-factor measurements, and we show that for output powers per channel ranging from −15 to 3 dBm the power penalty is less than 0.5 dB. 相似文献
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In optical time-division multiplexing (OTDM) systems using the four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) for time demultiplexing, the polarization states of control pulse and OTDM data lights are an important factor in the optical time demultiplexing process, which can influence the bit error rate (BER) of OTDM systems. In this paper, we analyze the effect of light polarization states on the FWM of a SOA, and use a simulation approach to study the BER performance of 100 Gbit/s OTDM systems that use the FWM in a SOA for optical time demultiplexing. It reveals that the BER or Q factor of OTDM systems is dependent on the misalignment θ between the polarization states of OTDM data and control lights. With increasing θ, both the optical power of resulting FWM component and the BER performance (or Q factor) of OTDM systems is degraded. For linearly polarized lights, our results show that the increase of BER and the reduction in Q factor are made smoothly when θ changes its value from 0° to 75°, whereas the degradation of BER and Q factor becomes rapid when θ exceeds 75°. Although the best system BER is obtained for θ = 0°, the BER performance can still tolerate some misalignment θ (e.g., up to 20° in our simulation). This is useful for the engineering design and applications of SOA-based optical time demultiplexers. 相似文献
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A deeper analysis of the second order polarization mode dispersion in optical communications systems
This article presents a new approach to the combined analysis of the first and second-order polarization mode dispersion (SOPMD) and shows their importance in optical communication systems performance. How it affects the relation between second-order polarization mode dispersion (PMD) and the differential group delay (DGD) in a single mode fiber is discussed. The analysis is based on time or wavelength and temperature variations changing/impacting PMD and DGD measured values. We present long term statistical characteristics of second-order PMD over a PMD emulator, and investigate the correlation between SOPMD, depolarization (DEP) and polarization dependent chromatic dispersion (PCD). Some authors calculate these modes from measurements obtained from the first order polarization mode dispersion, assuming a positive correlation between these effects, but this not the real relationship between them. A new interpretation of SOPMD was used to analyze the problem of the spectral stability in terms of the temperature. Actual techniques for determination SOPMD, consequently DEP and PCD, use the variation in time and/or wavelength. In some studies the results obtained for SOPMD are correlated to first-order PMD (FOPMD). This paper shows, based on measurements, that the correlation between first and second order Polarization Mode Dispersion (PMD) in the case where the last one is a function of the temperature can assume positive or negative values. 相似文献
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A paper [E. Mutafungwa et al., Optics Communications 198 (4) (2001) 339] reported the use of strict optical orthogonal codes (S-OOC’s) to reduce the four-wave mixing (FWM) crosstalk in dense wavelength-division multiplexing (DWDM) systems by using our S-OOC based unequal channel spacing (UCS) scheme and our special frequency sequences constructed, without referring to the original work. Some mistakes and inaccuracies are identified in the published paper regarding interpretation of S-OOC and its associated UCS scheme, which can cause the confusion of understanding the key concepts and principle about the S-OOC based UCS scheme. As a result, in this paper we present the necessary corrections and notes which deal with the major expressions and key concepts of both S-OOC’s and our proposed scheme. In doing so, the mapping of a S-OOC sequence to the UCS frequency set is appropriately interpreted, and the characteristics of S-OOC based UCS schemes are described. Moreover, the correct evaluation of optical bandwidths is presented for DWDM systems using S-OOC based UCS schemes, and the comparison of the repeated-codeword assignments with the overlapping-codeword assignments is also carried out. Furthermore, we discuss the effect of fractional-slot occupation for frequency assignments on the bandwidth expansion of UCS-DWDM systems. These in turn can lead to correctly understanding the principles of S-OOC based UCS schemes and applying them to assign the UCS frequencies to DWDM systems for the reduction of FWM crosstalk. 相似文献