【摘 要】
：
Three group velocity dispersion (GVD) compensation schemes, i.e., the post-compensation, precompensation and hybrid-compensation schemes, are discussed with considering polarization mode dispersion (PMD). In the 10- and 40-Gbit/s non-return-zero (NRZ) on-
【机 构】
：
NationalLaboratoryonLocalOptic-FiberCommunicationNetworks
【出 处】
：
ChineseOpticsLetters
论文部分内容阅读
Three group velocity dispersion (GVD) compensation schemes, i.e., the post-compensation, precompensation and hybrid-compensation schemes, are discussed with considering polarization mode dispersion (PMD). In the 10- and 40-Gbit/s non-return-zero (NRZ) on-off-key (OOK) systems, three physical factors, Kerr effect, GVD and PMD are considered. The numerical results show that, when the impact of PMD is taken into account, the GVD pre-compensation scheme performs best with more than 1 dB better of average eye-opening penalty (EOP) when input power is up to 10 dBm in the 10-Gbit/s system. However the GVD post-compensation scheme performs best for the case of 40 Gbit/s with input power less than 13 dBm, and GVD pre-compensation will be better if the input power increased beyond this range. The results are different from those already reported under the assumption that the impact of PMD is neglected. Therefore, the research in this paper provide a different insight into the system optimization when PMD, Kerr effect and GVD are considered.
其他文献
获得了BeAl2O4:Cr3 晶体的电子—振动激光输出。自由振荡阈值170焦耳,输出激光能量140毫焦耳,激光中心波长为7526埃。激光具有与结晶学b轴相平行的线偏振特性。用石英双折射滤光片作调谐元件,看到了激光的调谐输出。
以2,3-二乙酰对甲苯-D-酒石酸(D-H2DTTA)为原料，与金属Dy(III)盐反应，经过单晶-单晶转换，得到一种新的酒石酸(H2tar)配合物［Dy(Htar)3(H2O)3］n(1)，对该配合物用元素分析、红外光谱、X-射线单晶衍射、粉末衍射以及差热-热重等进行了表征。晶体结构分析表明，配合物1属三方晶系，R3空间群，晶胞参数为a=b=2.723 16(14) nm,c=0.762 75(6) nm,α=β=90.00°,γ=120.00°,V=4.898 5 (6) nm3,Z=3, 剑桥晶体数
第二相对增材制造钛合金材料的组织与性能有显著影响。将不同质量分数的B粉与Ti-6Al-4V粉末混合,在激光沉积制造(LDM)工艺下制备出块状样品,结合样品的室温拉伸性能,对第二相在显微组织形成、基体形变过程中的强化机制进行了讨论。研究结果表明,在LDM过程中,B与Ti-6Al-4V合金中的Ti发生原位反应,生成针状TiB第二相,并均匀分布于基体中。随合金中TiB含量的增加,原始β柱状晶尺寸逐渐减小,晶内片层状α相逐渐粗化,合金的室温拉伸强度和塑性均获得提高。TiB与基体α相间具有严格晶体学位相关系,在阻碍
Contrast enhancement is particularly important for imaging of weakly absorbing materials. We demonstrate the inherent contrast-enhancement effect at the edges of a transparent object by using a conventional pulsed terahertz imaging setup without additiona
研究制作了基于宽谱光源的光纤传感波长解调系统, 以多光纤光栅作为波长参考基准、采用可调谐光纤法布里-珀罗(F-P)滤波器作为波长扫描器件。系统中采用三次多项式拟合的方法对滤波器锯齿波的扫描电压与透射波长关系曲线进行非线性拟合, 解决可调谐光纤F-P滤波器的电压—波长非线性关系对系统测量带来的较大误差问题, 实现波长的高精度解调。采用五光纤光栅做波长参考, 单根光纤光栅传感器的解调实验结果表明：待测光纤光栅布拉格波长短期测量分辨率为3.5 pm, 长期测量稳定性为7 pm。采用该系统对光纤非本征法布里-珀罗
The propagation characteristics of laser-generated Lamb waves in thin composite plates are theoretically studied. Taking the anisotropic and viscoelastic properties of the composite material into account, the finite element models for simulating laser-gen
This study investigated the feasibility of photoacoustic(PA) imaging of bone and characterization of bone features. By conducting the experiments on bovine femoral heads ex vivo, the light and ultraso
基于对BiAlDyIG巨磁光材料的紫蓝光波段法拉第角频谱分析,采用新型热分解法工艺合成优质BiAlDyIG磁光薄膜,经快速循环晶化处理的结果表明,由于晶粒细化,其平均有效法拉第角比常规热处理后的样品大0.5°左右,且随循环数增加而增大。同时由于Al3 在四面体和八面体位的取代,导致居里温度下降(140～160 ℃),这些结果对提高磁光盘信噪比以及增大记录密度是极有意义的。
本文提出了一种新的制作纯位相型计算全息图的两孔编码方法并用实验加以证实.用本编码法制作的纯位相型计算全息图的特点是:(1)可记录、复现任意的复函数光场;(2)光场在全息图的光轴上再现,空间带宽积大,衍射效率高.
根据Zernike多项式的第四项系数q4和Seidel像差Focus项的对应关系，选用Zernike多项式第四项的系数q4的值作为激光干涉仪法定焦的判据。利用该判据定焦，方法可行，定焦结果稳定。根据q4值的正负可以判断干涉仪发出的球面波的交点处于大口径离轴抛物面平行光管的焦前或是焦后，从而指导干涉仪的前后移动。利用基于Zernike多项式的激光干涉仪法确定了大口径离轴抛物面平行光管的焦面，由标定实验可知，利用这种方法定焦效果不错，定焦后的平行光管出射光束平行性误差优于0.22″。