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随着大于40 Gb/s高速光通信系统的出现, 为了保证光信号传输质量, 需要对光信号进行监测。对于带宽超过传统光电探测器和示波器可测量带宽的高比特率数据光信号, 光采样技术是进行时域测量的重要手段。采用固定频差的方法可以用百兆速率的采样脉冲对高速光信号进行采样, 降低了对采样后电数据处理系统带宽的要求。在对基于周期极化铌酸锂(PPLN)波导中和频效应的采样过程进行建模仿真的基础上, 实现了对Optsim获得的光传输线内10 Gb/s的非归零码(NRZ)和归零码(RZ)信号的采样。采用软件同步算法对采样数据进行处理, 获得信号的眼图, 这一方法可使采样系统对硬件的要求降到最低。与理想与门获得的采样结果进行比较, 对PPLN波导的光采样特性和采样质量进行了分析。 相似文献
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双H型石英陀螺的音叉结构具有电极工艺简单的优点,但该陀螺的电容耦合噪声比H型石英陀螺的电容耦合噪声大.为减小电容耦合噪声,分析了双H型音叉的电容耦合噪声的影响和产生机理,采用ANSYS软件分析电容耦合噪声.在驱动电极上加载电压载荷,采用静态分析功能,在后处理器P0ST1中获取敏感电极的电荷量,利用电压和电荷的关系获取检测电极的耦合分布电容,采用这一指导原则,设计了一种新电极分布的音叉;通过仿真和测试对比了新电极和旧电极音叉的耦合分布电容,测试结果表明,新的电极设计的耦合电容值为旧电极的耦合电容值的50%左右.介绍了一种新的电极结构的双H型石英陀螺,并给出耦合电容的仿真分析及测试方法,该方法可以指导石英陀螺电极设计. 相似文献
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本文报道了作者采用实验室制备的Ti扩散LiNbO_3分支光波导调制器样品构成的光学双稳态装置(BOD)。对这类装置的稳态特性进行了理论上的分析与计算,并从实验上观察了装置的稳态特性,两者的结果有较好的一致性. 相似文献
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The robustness of the software-synchronized all-optical sampling for optical performance monitoring is estimated for 10-Gb/s fiber communication systems. It reveals that the software-synchronized algorithm is sensitive to the signal degradation caused by chromatic dispersion and nonlinearity in optical fibers. The influence of timing jitter and amplitude fluctuation of the sampling pulses is also investigated. It is found that stringent requirements are imposed on the quality of the sampling pulse and the tolerance of 1-dB Q penalty is measured. Considering the practically available optical sampling pulse sources, the results indicate that the amplitude fluctuation of the sampling pulses has the dominant impacts on the software-synchronized method. 相似文献
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A software synchronous optical sampling system is constructed based on sum frequency generation (SFG) in periodically poled lithium niobate (PPLN). Five gigahertz of a non-return-to-zero (NRZ) data signal is sampled by sampling pulse with the repetition frequency of 29.31 MHz. The power of the SFG light is set at 23 dBm, and an eye diagram is successfully recovered. A band-pass filter is added before the sampling pulse is subjected to erbium-doped fiber amplifier to reduce gain competition and ensure a high power level of SFG. 相似文献
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A tunable optical rail is embedded into the cavity of a nonlinear-polarization-rotation(NPR) mode-locked fiber laser to generate a sampling pulse with different repetition frequencies and realize bit-rate-adaptive software synchronous optical sampling.Two ultrashort pulses(20.26677 and 20.22900 MHz) are derived,and a 100-MHz data signal is sampled twice with these pulses based on sum-frequency generation(SFG) in periodically poled lithium niobate(PPLN).The eye diagram is successfully recovered,and an estimated bit rate of 102.22 MHz is derived.This method is feasible for bit rates ranging from 200 MHz to 1 GHz,with <3% relative error. 相似文献
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一个评价光谱估计精度的新参数 总被引:1,自引:0,他引:1
研究了对多光谱成像系统进行光谱估计的精度评价的问题。在给出光谱估计偏指数定义的基础上,提出了多光谱图像获取系统的光谱估计性能的评价的新方法——系统光谱匹配偏度指数法。该方法用一个指标来定量评价两光谱向量的光谱匹配程度,避免了以往评价参数的复杂性,同时反映了光谱反射率估计曲线实际测量曲线之间的差异程度。采用一典型多光谱相机对Macbeth色卡的24个典型光谱仿真估计所得的24个光谱对数值模拟,验证了光谱反射率估计匹配偏度指数能全面的反映光谱反射率的估计精度的设想;并拿17个多光谱估计系统的仿真估计的光谱数据,计算了它们的系统光谱估计偏度指数,计算结果有很好的一致性。结果还显示,系统光谱估计偏度指数还可用作对多光谱相机光谱估计性能进行等级划分的依据。 相似文献