【作者】 冯传奋；

【导师】 林金桐；

【作者基本信息】 北京邮电大学 ， 电磁场与微波技术， 2008， 博士

【摘要】 本论文的主要研究对象是光网络中基于半导体光放大器(SOA)非线性效应的全光信号处理技术,包括全光波长变换技术、全光解复用技术、全光格式变换技术和全光逻辑与门技术。论文提出了实现四种技术的几种新的方案,改进了相应的理论模型,并进行了相关的仿真和实验研究。另外,还研究了在相干光通信和干涉型光纤传感器中对干涉光偏振进行控制的输入偏振态动态反馈控制技术。第一部分:半导体光放大器的非线性偏振旋转特性及理论模型在原理论模型基础上,通过引入两个载流子温度方程来替代两个能量密度方程对原有模型进行改进,减少了模型计算的复杂度。在此理论模型基础上,仿真研究了SOA偏振相关的增益特性和相移特性。其仿真结果与相关的实验结果基本吻合。第二部分:基于SOA非线性偏振旋转效应的全光波长变换和解复用技术首次从仿真和实验两方面分别实现了两种基于SOA的非线性偏振旋转效应实现20Gbit/s的波长变换,并对这两种方案进行了对比。即:仅仅基于SOA的非线性偏振旋转效应实现波长变换和基于SOA的非线性偏振旋转效应辅助红移滤波技术实现波长变换。仿真结果与实验结果基本吻合。结果显示基于SOA的非线性偏振旋转效应辅助红移滤波技术实现波长变换的性能高于仅仅基于SOA的非线性偏振旋转效应实现波长变换的性能。首次利用改进的SOA非线性偏振相关模型对基于SOA的非线性偏振旋转效应在640Gbit/s的速率上实现了三种全光波长变换。即:仅仅基于SOA的非线性偏振旋转效应的波长变换、基于SOA的非线性偏振旋转效应辅助红移滤波技术的波长变换和基于SOA的非线性偏振旋转效应辅助蓝移滤波技术的波长变换。对上述三种640Gbit/s的全光波长变换方案进行了对比。研究了一些参数对波长变换性能(输出消光比ER)的影响。结果显示在相同的情况下基于SOA的非线性偏振旋转效应辅助蓝移滤波技术的波长变换方案具有最优的性能。首次利用改进的SOA非线性偏振相关模型对基于SOA的非线性偏振旋转效应实现了640Gbit/s到80Gbit/s的全光解复用并对此解复用方案进行了数值研究。包括:由时钟脉冲引起的开关窗口特性和一些参数对解复用性能(信道压制比)的影响,这些参数包括:输入时钟信号光功率、SOA注入电流、输入时钟信号脉冲宽度和偏振角度等。第三部分:基于SOA非线性效应的全光格式变换和全光逻辑与门技术独立提出了两种基于SOA的非线性效应辅助蓝移滤波的格式变换方案。即:利用非线性偏振旋转效应和蓝移滤波技术(NPR-BF)相结合的方案和利用交叉相位调制效应和蓝移滤波技术(XPM-BF)相结合的方案。介绍了这两种格式变换的基本结构和工作原理,通过实验实现了这两种格式变换。实验研究表明,在相同的条件下,NPR-BF格式变换方案要优于XPM-BF格式变换方案。运用改进的半导体光放大器非线性偏振相关模型,仿真实现了这两种格式变换方案。独立提出了一种基于SOA的非线性效应实现全光逻辑与门方案。介绍了这种全光逻辑与门的基本结构和工作原理,通过仿真在40Gbit/s的速率上实现了这种逻辑与门并与利用TOAD结构实现逻辑与门方案进行了对比。结果表明,在相同的条件下,提出的方案在输出消光比和码型效应方面都优于利用TOAD结构实现的与门方案。此外,仿真显示提出的方案可以操作在100Gbit/s的速率上。第四部分:输入偏振态动态反馈控制技术从一个崭新的角度对输入偏振态的动态反馈控制机理进行了透彻的理论分析和研究。通过理论分析建立了反馈控制模型,并进行了相关的仿真研究。分析了该反馈控制系统可能存在的稳定点,仿真结果显示对可见度五次方处理效果最好。更多还原

【Abstract】 This dissertation mainly focuses on the subject of all-optical signal processing technologies based on the nonlinearities in semiconductor optical amplifiers (SOAs), including all-optical wavelength conversion, all-optical demultiplexing, all-optical NRZ-to-RZ format conversion and all-optcial AND logic gate. Several new schemes are presented about the four kinds of super-high speed all-optical network technologies for the first time or independently. Numerical analyses based on the improved theoretical model and experimental analyses are conducted. In addition, the adaptive feedback control of the input polarization state used for controling the polarization state of the superposed beams in coherent optical fiber communications and optical fiber sensor devices is discussed in detail.1. Characteristics and theoretical model of nonlinear polarization rotation in SOATwo carrier temperature equations are introduced to substitute two energy density equations to reduce the complexity of calculation compared to the previous model. Based on the improved model, numerical analyses are conducted about polarized characteristics of gain and phase shift in SOA. The simulated results are good agreement with the experimental results.2. All-optical wavelength conversion and demultiplexing based on nonlinear polarization rotation in SOATwo kinds of wavelength conversion schemes based on nonlinear polarization rotation in SOA are analyzed by simulation based on the improved model and experiment at 20Gbit/s in detail for the first time, which are the wavelength conversion scheme only based on nonlinear polarization rotation in SOA and the wavelength conversion scheme based on nonlinear polarization rotation in SOA assisted with red-shifted filtering. The simulated results are good agreement with the experimental results. The results show that the performance of the wavelength conversion scheme based on nonlinear polarization rotation in SOA assisted with red-shifted filtering is higher than that of the wavelength conversion scheme only based on nonlinear polarization rotation in SOA.Three kinds of all-optical wavelength conversion schemes based on nonlinear polarization rotation in SOA are achieved at the rate of 640Gbit/s for the first time, which are all-optical wavelength conversion scheme only based on nonlinear polarization rotation in SOA, all-optical wavelength conversion scheme based on nonlinear polarization rotation in SOA assisted with red-shifted filtering and all-optical wavelength conversion scheme based on nonlinear polarization rotation in SOA assisted with blue-shifted filtering. Three kinds of 640Gbit/s all-optical wavelength conversion schemes are compared. The effects of some key parameters on the performance of the three kinds of wavelength conversion schemes are investigated. The results show that the performance of the all-optical wavelength conversion scheme based on nonlinear polarization rotation in SOA assisted with blue-shifted filtering is highest among them at the same conditions.640Gbit/s to 80Gbit/s all-optical demultiplexing scheme based on nonlinear polarization rotation in SOA is invesitaged by numerical simulation for the first time, which include the characteristics of switching window induced by clock pulses and the effects of some key parameters on the performance of the demultiplexing scheme, shch as the injected power of clock signal, the injected current of SOA, the pulse width of the injected clock pulse and the polarization angle of the injected clock signal.3. All-optical NRZ-to-RZ format conversion and all-optical AND logic gate based on the nonlinearities of SOATwo novel schemes are independently proposed to achieve NRZ-to-RZ format conversion by exploiting nonlinearities in SOA assisted with blue-shifted filtering, which are the NRZ-to-RZ format conversion based on nonlinear polarization rotation in SOA assisted with blue-shifted filtering (NPR-BF) and the NRZ-to-RZ format conversion based on cross-phase modulation in SOA assisted with blue-shifted filtering (XPM-BF). The basic structures and principles of the two kinds of NRZ-to-RZ format conversions are presented and the two kinds of NRZ-to-RZ format conversions are also achieved by experiment. The experimental results show that the performance of NPR-BF scheme is higher than that of XPM-BF scheme at the same conditions. The two kinds of NRZ-to-RZ format conversions are also achieved by simulation besed on the improved model of nonlinear polarization rotation in SOA.A novel scheme is independently proposed to achieve all-optical AND logic gate by exploiting nonlinearities in SOA. The basic structure and principle of all-optical AND logic gate is presented and is also achieved by simulation at the rate of 40Gbit/s. Through numerical analyses and discussions, it can be seen that the performance of the proposed scheme is higher than that of Terahertz optical asymmetric demultiplexer scheme in terms of the output extinction ratio (ER) and the output pattern effect at the same conditions. Furthermore, the proposed scheme is potentially capable of AND operation speed to 100Gbit/s.4. Technology of adaptive feedback control of the input polarization stateNovel theoretical analyses on the adaptive feedback control of the input polarization state are presented. The model of the adaptive feedback control is established by the theoretical analyses. The possible steady points of the control system are also presented. The simulated results illustrate that the best performance can be obtained when the five power of visibility is considered as feedback signal.更多还原