【作者】 杨世云；

【导师】 余重秀；

【作者基本信息】 北京邮电大学 ， 光学， 2009， 硕士

【摘要】 光子晶体光纤(photonic crystal fiber,PCF)由于具有结构可控的灵活性和新颖的传输特性而成为近年来国内外研究的热点。光子晶体光纤具有极强的非线性特性,它在超连续谱产生及参量放大器、光纤激光器、光纤光栅、光开关等光纤器件制作方面有非常广泛的应用前景,并且有可能对非线性光纤光学的发展起更加重要的推动作用。因此,对于光子晶体光纤中的各种非线性效应——自相位调制(SPM)、交叉相位调制(XPM)、四波混频效应、受激拉曼散射和受激布里渊散射等的理论研究和实验分析便具有相当重要的意义,可为基于非线性效应的光纤器件的研制提供理论基础。本论文主要内容如下:1)本论文在国内外现有成果的基础上,对光子晶体光纤中的SPM和XPM效应及其应用进行了研究。介绍了光子晶体光纤的非线性特性及其应用研究背景,说明了本论文研究的重要意义。2)利用光子晶体光纤的自相位调制和交叉相位调制效应实现孤子自俘获,并基于分步傅里叶方法,利用Matlab仿真分析了在光子晶体光纤的反常色散区,光子晶体光纤的特性参数如群速度失配因子、三阶色散、自陡峭因子和脉冲内拉曼散射因子对孤子自俘获效应的影响。这对于研究设计一种新型微结构光纤用于产生优良的孤子自俘获效应具有重大意义,基于此效应可以实现高速的全光开关。3)基于双折射光子晶体光纤的脉冲俘获现象实现全光开关,通过改变信号脉冲串之间的时间间隔控制全光开关的阈值功率,可以达到T HZ;基于光子晶体光纤构成非线性光纤环镜,利用光子晶体光纤中的自相位调制效应,不加入控制脉冲实现光开关。研究表明高非线性光子晶体光纤的非线性系数γ_p越大、长度L越长,开关的性能也就越好,并且该光开关具有降低噪声和脉冲整形的功能;基于高非线性光子晶体光纤构成非线性光纤环镜,使用平行排列的3×3光纤耦合器,利用光子晶体光纤中的交叉相位调制效应使反向传输的两路信号光产生非线性相移,从而实现了双端口输出光开关。此光开关可用于实现开关信号检测、时钟提取和信号处理等功能,是实现双环全光缓存器的基础。更多还原

【Abstract】 Photonic Crystal Fiber (PCF) becomes Research hotspot because of its flexibility of the controllable structure and novel transmission characteristics recently. PCF has highly nonlinear characteristics, which has very broad application prospects in the production of fiber-optic devices such as supercontinuum generation、parametric amplifier、fiber laser、fiber Bragg grating、optical switching and so on, and it maybe play more important part in the development of nonlinear fiber optics. So the theoretical research and experimental analysis of self phase modulation (SPM)、cross-phase modulation (XPM)、four-wave mixing (FWM)、stimulated raman scattering and stimulated brillouin scattering have important significance, it can provide theoretical foundation for the development of fiber-optic devices based on nonlinear effect.The paper mainly involves the following several aspects:1) Based on home and abroad Research results, SPM and XPM of PCF are researched. The PCF nonlinear characteristics and its application research background are introduced, the significance of this paper is explained.2) Soliton self-trapping is realized using the SPM and XPM of PCF, and the influence of PCF characteristic parameters such as group velocity mismatch factor, third-order dispersion, the steep factor and pulse within the raman scattering factor on soliton self-trapping is researched using Matlab based on split-step fourier method in the anomalous dispersion regime of PCF. This research has great significance for research and design a new type of microstructure fiber used to produce an excellent effect of soliton self-trapping, which can be used to realize high speed all-optical switching.3) All-optical switching is realized based on soliton trapping of birefringent PCF and its threshold power can reach THZ through changing the time lag between signal pulses. Optical switching is realized by SPM of PCF without control pulse and the performance of this switch which has lower noise and pulse shaping function becomes better as nonlinear coefficientγ_p of PCF bigger and PCF length longer. Dual-port output of optical switching is achieved using parallel array of 3×3 optical fiber coupler and XPM of PCF based on nonlinear optical loop mirror. This switch can be used in realizing switching signal detection, clock extraction, signal processing functions and is also the basic of double-ring all-optical buffer.更多还原