【作者】 张艳冬；

【导师】 鲍振武； 于晋龙；

【作者基本信息】 天津大学 ， 通信与信息系统， 2006， 硕士

【摘要】 随着通信容量需求地不断增加,光传送网向着高速率、长距离方向发展,并在此基础之上,最终实现全光网络。由于色散、非线性效应以及其它不利因素地影响,使得信号在传输过程中,质量下降,导致传输距离、传输速率受限。为解决信号恶化的问题,全光3R(Re-amplifying,Re-shaping,Re-timing)技术应运而生。全光3R中的关键技术是全光时钟提取,同时,它也是全光网的关键环节,本论文工作围绕基于F-P滤波器的全光时钟提取技术展开。对基于SOA的XGM效应的波长变换进行了分析,研究了各种外部参数和SOA内部参数对波长变换的影响,利用Optisystem3.0进行了仿真。进行相应实验时,在综合考虑影响波长变换效果的各条件的前提下,取得了良好的实验效果,为以后时钟提取中的波长变换,奠定了工作基础。利用SOA的传输函数的频域形式,对SOA对信号调制深度地改变进行了理论分析,并得到结论:SOA对低频频率成份有很好地抑制作用。随后通过实验进行了验证。针对全光时钟提方案中的关键器件F-P滤波器,进行了详尽的理论分析。在此基础之上,利用仿真软件Optisystem3.0模拟了F-P滤波器不同精细度、激光器中心波长偏移对全光时钟提取的影响。为了使全光判决取得良好效果,确定了以下全光时钟提取方案:首先对信号进行波长变换,将其所携带的信息转移到波长稳定的激光器所产生的连续光上,继而用高精细度的F-P滤波器进行时钟提取。利用Optisystem3.0对拟采取的实验方案进行全面仿真,并提出了利用窄带滤波器改善时钟信号消光比的方法:窄带滤波器要有足够小的带宽,且相对于光载波的中心波长有一定的偏移。随后利用SOA来抑制时钟的低频噪声。最后进行了全面实验,成功地利用此方案实现了40Gbps时钟提取实验,得到了较高质量的时钟。不但验证了前述工作的正确性,并取得了良好的实验结果。更多还原

【Abstract】 As the increase of demand for communication capacity, optical-transport-network develops toward high speed and long haul, and all-optical network finally. However, the transmission distance and speed are limited, because the signal is degraded caused by the dispersion and nonlinear effects during transmission. All-optical 3R is the very technology developed to solve this problem. The all-optical clock recovery is the key of all-optical 3R and all-optical network. All-optical clock recovery using F-P filter is chiefly talked about in this thesis.Work is carried out to study the wavelength conversion basing on cross gain modulation (XGM) of SOA and how it being affected by kinds of external and internal parameters of SOA , then it is simulated using the software named Optisystem3.0. The corresponding experiment is finished successfully after all the parameters being considered, and it prepares for the wavelength conversion used in clock recovery.It is analyzed theoretically of how SOA affects the modulation-depth of the signal according to the transport function of SOA about frequency,and a conclusion is given: the low-frequency can be suppressed by SOA. Then it is proved through experiment. F-P filter is analyzed theoretically in detail as the key component in all-optical clock recovery. Then, how the differential finesses of F-P filter and the excursion of the central wavelength of laser affecting the clock recovery are simulated using Optisystem3.0.For good result in all-optical decision, the scheme of all-optical clock recovery is plotted as follows: first, the information carried by the carrier is transferred to the continuous wave from a laser with steady central wavelength, then clock is recovered using F-P filter. It is simulated using Optisystem3.0, and the extinction-ratio of the clock is improved using a narrow-band-pass filter with enough narrow bandwidth and a little excursion of its center to the central wavelength of the laser, on the other hand, the low frequency noise in the clock is suppressed using SOA.40Gbps clock is recovered successfully using this scheme through comprehensive experiment. Not only the validity of previous work is proved, but also good experiment results are accomplished.更多还原