共查询到20条相似文献,搜索用时 218 毫秒
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在导出自相位调制和交叉相位调制共同作用所致相位调制频率啁啾的基础上,数值研究了相位调制频率啁啾与初始啁啾的关系,并对有和无初始啁啾40Gbit/s归零码(RZ)在二阶和三阶色散完全补偿(路径平均色散为0)的色散管理偏振复用孤子传输系统中的传输效果进行计算。结果表明,在输入功率达到一定值时,初始啁啾参量C对相位调制频率啁啾的作用,决定着系统偏振复用孤子技术的成效及传输性能,适当选取初始啁啾参量C能够有效抑制偏振模色散,提高孤子脉冲稳定传输距离。 相似文献
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物联网、虚拟现实及人工智能等技术的发展加大了对光纤接入无源光网络带宽的需求,其中调制器成为制约无源光网络带宽的关键因素。结合了直接调制激光器和外调制器各自优势的啁啾管理激光器以产生结构简单、便于集成等特点受到了广泛关注。采用耦合速率方程理论研究了啁啾管理激光器的动力学特性,分析了40 Gbit/s啁啾管理调制格式的产生原理及时频域特性,并在高速无色散补偿接入网中与由外调制器产生的40 Gbit/s非归零调制格式进行了性能对比。结果表明,带宽为48.5 GHz的40 Gbit/s啁啾管理调制格式在1 dB灵敏度代价下所对应的色散容限为215 ps/nm,与非归零调制格式相比其无色散补偿传输距离增加了1.6倍,表现出了强的抗色散能力,在高速接入网中也体现了较高的应用价值。相关结果可为实际系统设计提供理论参考。 相似文献
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基于双折射光纤中光脉冲传输方程,详细分析了二阶色散、自相位调制以及交叉相位调制在光脉冲传输过程中引起的啁啾。分析结果显示:通过合理选取入射功率,二阶色散引起的啁啾与自相位调制引起的啁啾在脉冲中心附近可以相互抵消,从而使脉冲展宽最小;交叉相位调制产生的两偏振分量的啁啾引起的频移,可使两偏振分量间产生互束缚,利用这种现象可以抑制偏振模色散。 相似文献
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基于双折射光纤中光脉冲传输方程,详细分析了二阶色散、自相位调制以及交叉相位调制在光脉冲传输过程中引起的啁啾。分析结果显示:通过合理选取入射功率,二阶色散引起的啁啾与自相位调制引起的啁啾在脉冲中心附近可以相互抵消,从而使脉冲展宽最小;交叉相位调制产生的两偏振分量的啁啾引起的频移,可使两偏振分量间产生互束缚,利用这种现象可以抑制偏振模色散。 相似文献
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CHEN Ming YIN Fei-fei HE Li-na ZHANG Ye-jin YANG Si-gang CHEN Hong-wei XIE Shi-zhong 《光电子快报》2007,3(5):359-362
A remnant dispersion monitoring method based on spectral-shift of SOA in high speed optical communication system with CSRZ format and single channel speed of 40 Gbit/s is proposed. The system performance can be optimized by careful choosing bandwidth and center wavelength of the optical fiber grating filter. The dynamical monitoring range is ±60 ps/nm and the monitoring precision is about 5 ps/nm. This method can be suitable for the application in dynamical dispersion compensation of high speed optical communication systems. 相似文献
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为了提高调制器的灵活性和可扩展性,设计了一个中心频率和符号速率可调,且支持多种调制体制的高速通用数字调制器方案,并能产生中频为80MHz,带宽为7.9365MHz的正交相移键控(QPSK)信号和16QAM(正交幅度调制)信号。集中论述基于软件无线电的通用调制算法、符号映射原理和高速成形滤波模块的具体实现。测试结果表明,该方案开放性好,结构简单,体积小,具有一定的实用性和通用性。 相似文献
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We present the dispersive characteristics of an electronically tunable optical filter, with application toward delaying high speed digital and analog signals. Square waves can be dynamically delayed and reshaped through a change in injection current to the filter. Since the filter is of an all-pass nature, its usable bandwidth is limited primarily by the phase response (dispersion). We show that for 2-GHz square waves, dispersion is not a limiting factor and the filter can be operated over the full range of delays. At 5 GHz, the pulses can still be delayed, however the range of operation is dispersion limited. Additionally, at 5 GHz this dispersion can be harnessed for pulse reshaping applications. The filter is studied both experimentally and theoretically, demonstrating good agreement. 相似文献
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A new polarization-independent tunable spectral filter based on the combination of a single isotropic acoustooptic cell and a pair of conventional diffraction gratings is suggested and investigated. The filter features narrow bandwidth, frequency shift compensation, and low polarization dependence. Using standard AMTIR-1 chalcogenide glass acoustooptic modulator with frequency 40-77 MHz and ruled diffraction gratings with 600 grooves/mm, a 3-dB bandwidth of 1.1 nm, and a tuning range of 16 nm were obtained. Tuning range can be increased by the use of acoustooptic cell with increased center frequency or diffraction grating of a lower dispersion. Inserting the filter inside a laser cavity, continuous-wave tunable generation of Er-doped fiber laser with maximum output power 3 mW was realized. When a Fabry-Perot etalon (0.166-nm free spectral range, 40% reflectance) was inserted into laser cavity, the linewidth was observed to be less than 0.05 nm 相似文献
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Mercier D. Orlianges J.-C. Delage T. Champeaux C. Catherinot A. Cros D. Blondy P. 《Microwave Theory and Techniques》2004,52(4):1175-1181
Distributed microelectromechanical varactors on a coplanar waveguide have been used to design a two- and four-pole bandpass tune-all filters. The two-pole initial bandwidth is 6.4% at 44.05 GHz with a mid-band insertion loss of 3.2 dB and with matching better than 15 dB. The four-pole initial bandwidth is 6.1% at 43.25 GHz with a mid-band insertion loss of 6.5 dB and with matching better than 10 dB. The use of microelectromechanical system bridges allows a continuous tuning for both center frequency and bandwidth. The varactors biasing network has been designed so that the center frequency and bandwidth can be tuned separately. The two-pole filter center frequency can be changed from 44.05 to 41.55 GHz (5.6% tuning range), while the bandwidth can be independently changed from 2.8 to 2.05 GHz. The four-pole filter center frequency can be changed from 43.25 to 40.95 GHz (5.3% tuning range) and the bandwidth can be changed from 2.65 to 1.9 GHz. 相似文献
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Vacondio F. Ghazisaeidi A. Bononi A. Rusch L.A. 《Lightwave Technology, Journal of》2009,27(22):5106-5114
In this paper, we investigate experimentally and via simulation the pros and cons of a narrow filter receiver for differential quadrature phase-shift keying based on a single optical filter and eschewing the conventional asymmetrical Mach-Zehnder interferometer structure. We quantify the performance differences between the two receivers, allowing system designers and operators to determine when the less complex narrow filter receiver might be the appropriate choice. We numerically optimize the 3-dB bandwidth and center frequency of the narrow filter and show it is more robust to carrier frequency detuning than the conventional solution. We show that the narrow filter receiver is more tolerant to chromatic dispersion (CD) than the conventional one, and equally tolerant to first-order polarization-mode dispersion. We show the impact of the 3-dB bandwidth on the receiver performance when CD accumulates. Finally, we show via experiments and simulations that the 3 dB advantage of the conventional receiver vanishes when the nonlinear impairments are fiber nonlinearities; comparing the two receivers at the optimum launch power for a 25 times 80 km system, the difference in optical SNR margin is reduced to ~1.6 dB. Experiments are conducted at 42 Gb/s using a commercially available narrow filter for reception. 相似文献