【作者】 王刚；

【导师】 杨学林；

【作者基本信息】 上海交通大学 ， 信息与通信工程， 2013， 硕士

【摘要】 在光纤通信系统中，全光波长转换是波分复用的一项关键技术，它提供了波长路由和波长再利用功能，不但有效地节约网络资源（光纤、节点波长），降低网络的阻塞率，而且可以简化网络管理并降低网络互连的复杂度。相对于传统的光/电/光（O/E/O）波长转换方式，全光波长转换在光域上直接进行光信号的波长转换，易于实现高速光信号的的波长转换，并大大降低系统反复光电转换带来的系统复杂度与能耗。实现全光波长转换的一个关键因素是采用高非线性光学效应的器件。半导体光放大器（Semiconductor Optical Amplifier, SOA）因为具备体积小、可集成、功耗低、工作波长范围宽以及较高的非线性光纤效应等优点，十分适合用来实现全光波长转换器等功能，故成为近年来该领域研究的热点。本文将围绕基于半导体光放大器的全光波长转换进行理论与实验研究，具体工作如下：（1）研究SOA的时域模型，从时域上分析了NRZ信号的SOA-MZI波长转换器。提出了针对NRZ信号，基于SOA-MZI的波长转换和光逻辑异或门（XOR）的新结构。通过采用信号光的反相信号，用于补偿SOA的码型效应，以提升NRZ信号波长转换和逻辑异或的速率。仿真结果显示，这两种新的方案可以有效地减少输出信号的“1”与“0”之间的过渡时间，降低脉冲展宽的影响，将上述波长转换和光逻辑异或两种器件的工作速率提高到了40Gb/s。仿真结果表明，采用该方法的输出光具有较高的信号质量，其品质因子Q均大于6。（2）建立了一个SOA的频域模型，并用此频域模型理论分析了基于SOA的加速开关工作原理与工作频率带宽。该模型采用小信号分析理论变换了SOA的载流子速率方程和行波方程，在傅里叶变换后得到SOA光功率和相位的频域方程，进而得到SOA器件的频率响应特性，即器件的传递函数。在此频率模型的基础上，仿真模拟了传递函数曲线，并分析了SOA增益、延迟干涉仪的相移等参数对传递函数曲线的影响。针对基于SOA的三种加速开关结构，我们详细地推导了其传递函数，并作了对比，结果与实验结果吻合。通过优化器件参数与结构，实现了加速开关的最优结构与性能。最后，我们还分析了多个SOA级联时的开关结构与性能的关系。（3）进行了SOA-MZI型的波长转换器的实验研究，包括SOA-MZI中单个非线性SOA的交叉增益调制（XGM）特性的实验，SOA-MZI型全光波长转换XPM方案实验以及SOA-MZI型全光波长转换差分XPM方案实验。通过实验，我们分析了SOA的增益恢复时间，以及SOA-MZI型全光波长转换器工作在不同速率下的波长转换性能。实验结果显示，SOA-MZI能实现40Gb/s-80Gb/s转换速率的全光波长转换。更多还原

【Abstract】 All-optical wavelength conversion (AOWC) has emerged as apromising technique for wavelength division multiplexing (WDM) inoptical fiber communication systems. AOWC provides the functions ofwavelength routing and wavelength reuse, which can save networkresources like optical fiber and wavelengths, efficiently solve the datablocking problems in the optical fiber networks, simplify the managementof networks and reduce the complexity of the network interconnection.Compared to traditional optical-electrical-optical (O-E-O) wavelengthconversion, AOWC operates purely in the optical domain, and thus itoffers the benefits of higher data rate operation, and lowers the systemcomplexity and energy consumption. In recent years, AOWC incorporatingsemiconductor optical amplifiers (SOAs) has been one of the hot researchtopics since it could be particularly attractive due to the facts of its smallsize, lower power consumption, ease of integration, and highnonlinearities.In the thesis, both of the theoretical and experimental researches ofthe AOWC based on SOAs will be given. The research results will bepresented as follows:1) A time-domain model of SOA is studied, and we deeply analyse theAOWC based on SOA-based Mach-Zehnder interferometers (SOA-MZIs)using this model. We propose an all-optical AND/XOR gates fornon-return-to-zero (NRZ) data using SOA-MZI. For AND/XOR gates, thecomplementary data is applied as the additional input to SOA-MZIs, inorder to mitigate the pattern effect of SOAs, while increase the operationdata rate for NRZ signal up to40Gb/s. Numerical simulations have shownthat, the proposed novel scheme can effectively mitigate the patterningeffect in SOAs via shortening the rising/falling transition times of theoptical signals. The high quality of the output signal (Q>6) are numericallyevaluated for both AND/XOR gates.2) A frequency-domain model is established for SOAs, which is used to analyse all-optical turbo-switch incorporating two cascading SOAs infrequency-domain. This model exploits the small-signal analysis theoryand Fourier transform to transform the rate equations and travelling-waveequations into frequency equations for optical power and phase shift inSOA. And we get the the the small-signal frequency response (SSFR)which represents the transfer function of SOA. On the basis of the model,we simulate the SSFR curves and analyze the influence of SOA gain andthe phase-shift of delayed interferemeter (DI) on the SSFR curves. In termsof the three different structures of turbo-switches, we deduce the SSFRs.The results are in good agreement with the reported experiment results.After optimizing the device parameter and turbo-switch structure, wesuggest the optimum structure which outputs the best performance. Inaddition, we analyse the influence of the number of the cascaded SOAs onswitching bandwidth.3) The AOWC experiments are performed to study the AOWC basedon a SOA-MZI, which including the research of cross gain modulation(XGM) and the cross phase modulation (XPM) inside SOA-MZI. Inaddition, the differential XPM scheme is evaluated by the experiment ofpush-pull approach based on a SOA-MZI. In the experiments, the gainrecovery time of a single SOA, and the performance of AOWC are givenin terms of high-speed data pattern and the eye diagrams. It isdemonstrated that, the AOWC base on a SOA-MZI can be operated at thedata rate up to40-80Gb/s.更多还原