【作者】 张蕾；

【导师】 王肇颖；

【作者基本信息】 天津大学 ， 物理电子学， 2010， 硕士

【摘要】 波分复用(WDM)技术是目前大容量光纤通信网普遍采用的技术,为了进一步提高通信容量,波分复用通信系统正朝着信道数越来越多的方向发展。多波长光源是波分复用传输系统的核心技术之一。本论文主要围绕多波长光纤光源进行了以下几个方面的研究:一、C+L带多波长光纤激光器的理论研究1)为C+L带多波长光纤激光器建立光纤环形腔模型,阐述了该模型的可行性。2)给出系统中关键器件半导体光放大器(SOA)的经典数学模型,并对SOA的增益饱和特性进行研究,分析了注入电流和入射光功率对其增益的影响。3)介绍了对自发辐射噪声(ASE)的处理方法,模拟出不同入射光功率下的ASE输出光功率谱和SOA自发辐射光子密度图。4)讨论了高双折射光纤环形镜的滤波特性,并对自发辐射谱进行滤波,数值模拟了该光纤激光器稳态输出时的情况。二、C+L带多波长光纤激光器的实验研究1)对基于两个SOA级联的C+L带多波长光纤激光器进行分组实验,分析了SOA的注入电流、峰值增益波长以及级联顺序对输出结果的影响。实验得到符合ITU-T标准间隔100GHz的16个波长输出,各信道输出功率差小于6dB,输出的多波长位于C+L带,各波长的3dB线宽小于0.23nm。调节腔内的偏振控制器,实现了这组波长在50GHz范围内的整体连续可调谐。2)对加入单程反馈信号的C+L带多波长光纤激光器进行实验,实现了输出功率谱的平坦化。实验获得符合ITU-T标准间隔100GHz的27个波长的输出,各信道输出功率差小于6dB。3)改变激光腔输出耦合器的输出比,分析其对输出结果的影响。耦合比为60:40时,实验获得了符合ITU-T标准间隔100GHz的16个波长输出,各信道输出功率差小于4dB。4)利用未泵浦的掺铒光纤对该多波长光纤激光器进行压窄线宽的实验。实验获得基本符合ITU-T标准间隔100GHz的19个波长输出,各信道输出功率差小于6dB,波长的3dB线宽被压窄为0.16nm。更多还原

【Abstract】 The technology of wavelength division multiplexing (WDM) is widely used for the high-capacity fiber-optic network. In order to enhance the communication capacity, WDM transmission system is moving in the direction of increasing channels. Multi-wavelength light source is a core technology in wavelength division multiplexing transmission system. This dissertation is focused on multi-wavelength lasers, which include:1. The theoretical research on C+L band multi-wavelength fiber laser1) A theoretical model for the C+L band multi-wavelength fiber laser is constructed and the feasibility of the model is explained clearly.2) The classical model for the semiconductor optical amplifier (SOA) is given. The static gain saturation in SOAs is numerically simulated. The results of SOA gain versus injected current and the input optical power are analyzed.3) The approach of the spontaneous emission noise is introduced. The graphs of ASE and SOA spontaneous emission photon density are simulated.4) The high-birefringence fiber loop mirror filter is analyzed and the steady output of the fiber laser is simulated.2. Experimental research on C+L band multi-wavelength fiber laser1) For the two cascaded structures which are composed by SOAs, the corresponding multi-wavelength fiber lasers are experimented and the experimental results are compared. The impact to the laser by the current, the peak gain wavelength and the sequence of the cascaded structure is discussed. One of the experiment results is simultaneous lasing of 16 wavelengths with spacing on ITU-grid(100GHz). The output power variation is less than 6 dB and it is basically in the C+L band. Its 3dB width is about 0.23nm. By adjusting the states of polarization controller, these wavelengths can be tuned together over 50GHz.2) One-way feedback signal on the C+L band multi-wavelength fiber laser is experimented. The output power is much flatter and the multi-wavelength number is increased significantly due to the feedback signal. Experiments achieve 27 wavelengths which comply with ITU-T standard interval of 100 GHz. The output power variation is less than 6 dB3) The ratio of the coupler in the laser cavity is changed separately. When the ratio is 60:40, 16 wavelengths are achieved whose output power variation is less than 4 dB.4) A non-pumped erbium-doped fiber (EDF) is added to narrow the line widths of the output wavelengths. During the experiments, 19 wavelengths are achieved whose 3dB line width is reduced to 0.16 nm with the output power variation less than 6 dB.更多还原