基于级联型光纤的孤子自频移增强特性

设计了一种10m掺铥光纤级联于3m大模场光子晶体光纤末端的结构,利用400fs、1 550nm脉冲光产生孤子自频移,在入射光功率相同的情况下,掺铥光纤末端的孤子频移量比大模场光纤末端多100~150nm,平均多30%左右.孤子与泵浦光在掺铥光纤末端的输出光谱表明,残留泵浦光作用于Tm3+,在1.8~2.1μm范围产生受激辐射,从而增强了拉曼效应,导致孤子自频移增强.实验结果揭示了一种增强孤子自频移效应的方法,对于了解孤子在光纤中频移特性和提高基于孤子自频移的可调谐光源的调谐范围等具有参考意义.     

饱和非线性效应对负折射材料中孤子自频移的影响

以描述负折射材料中包含拉曼效应的高阶非线性薛定谔方程为模型,采用分步傅里叶算法数值分析了高阶效应,尤其是饱和非线性效应对自聚焦负折射率材料中的孤子拉曼自频移的影响。结果表明,在自聚焦负折射率材料中饱和非线性效应使孤子拉曼自频移速度加快;饱和非线性效应与负的自陡效应共同作用进一步加快孤子自频移的速度;饱和非线性效应同正的自陡效应、三阶色散效应共同作用时孤子拉曼自频移在整体上受到抑制。     

基于孤子自频移现象的高比特全光量化仿真研究EI北大核心CSCD

探讨了基于孤子自频移(SSFS)效应的高精度全光量化技术。通过仿真分析孤子自频移特性,发现当输入脉冲的脉宽在150 fs时,量化比特位(NOB)可以达到8,对应的有效比特位(ENOB)为7.02。更小的脉宽无法保证量化比特位,而更宽的脉宽则会影响量化函数的线性度,降低有效比特位。150 fs对应的谱宽9.8 nm和平均功率0.92 W(50 GHz的脉冲速率下)也都可以较容易地由已有的光学技术得到。而啁啾会展宽脉宽,显著降低量化比特位和有效比特位,因此需尽量避免。     

单模光纤中喇曼类孤子脉冲理论研究

本文在考虑群速度色散(GVD)、受激喇曼散射(SRS)、自相位调制(SPM)、交叉相位调制(XPM)及光纤损耗同时作用的条件下,建立了关于单模光纤中喇曼类孤子的理论计算模型。通过模拟计算Gouveia-neto等人的实验,得到了84fs的喇曼类孤子脉冲,与其实验结果基本一致,并给出了喇曼类孤子脉冲形成过程的图象和新见解。 关键词：     

飞秒脉冲作用下光子晶体光纤超连续谱的产生

采用钛宝石超快fs激光器泵浦2m长光子晶体光纤产生超连续谱,重点研究了不同输入功率下350～959nm波长范围内光谱的演变过程,实验中产生的超连续光谱宽度超过550nm分析表明,内脉冲喇曼散射和孤子自频移在开始阶段对光谱长波方向上的展宽起主要作用,这些新的频率成分与随后光谱向短波方向的拓展有密切关系.     

自陡峭和自频移效应对有限背景解的影响

基于自聚焦的非线性薛定谔方程,研究了自陡峭效应和自频移效应对Peregrine怪波(PS)、Akhmediev呼吸子(AB)和Kuznetsov-Ma孤子(KMS)传输特性的影响。数值模拟结果表明:这两种效应使三种有限背景解分裂加快,相邻最大压缩脉冲间的距离减小,脉冲中心发生偏移,且参数越大,分裂得越早,脉冲中心偏移量越大。     

色散渐变光纤中的亚皮秒孤子传输

当皮秒孤子在群色散指数衰减的色散渐变光纤中传输时,孤子的群色散和自相位调制保持局域平衡,宽度可以保持不变,但对亚皮秒孤子,由于受拉曼自频移效应和三阶色散效应的共同影响,要想继续保持群色散与自相位调制的局域平衡,光纤的群色散分布应加以修正,对传输亚皮秒孤子的色散渐变光纤的群色散分布加以修正,讨论并对亚皮秒孤子的传输情况进行了数值模拟,模拟结果与理论一致。     

Reduction of Soliton Interaction in Distributed Erbium-Doped Fiber Amplifiers

Methods of reducing the soliton interaction in distributed erbium-doped fiber amplifiers have been studied. The results show: if the optical phase conjugation is applied in proper periodic length, input relative phase between two solitons, and non-equal amplitude input is chosen, the soliton-soliton interaction and soliton self frequency shift can be deleted effectively.     

Broadband tunable Raman soliton self-frequency shift to mid-infrared band in a highly birefringent microstructure fiber

Raman soliton self-frequency shifted to mid-infrared band(λ 2 μm) has been achieved in an air-silica microstructure fiber(MF). The MF used in our experiment has an elliptical core with diameters of 1.08 and 2.48 μm for fast and slow axis. Numerical simulation shows that each fundamental orthogonal polarization mode has two wide-spaced λZDW and theλZDW pairs located at 701/2110 nm and 755/2498 nm along the fast and slow axis, respectively. Using 810-nm Ti:sapphire femtosecond laser as pump, when the output power varies from 0.3 to 0.5 W, the furthest red-shift Raman solitons in both fast and slow axis shift from near-infrared band to mid-infrared band, reaching as far as 2030 and 2261 nm. Also, midinfrared Raman solitons can always be generated for pump wavelength longer than 790 nm if output pump power reaches0.5 W. Specifically, with pump power at 0.5 W, the mid-infrared soliton in slow axis shifts from 2001 to 2261 nm when the pump changes from 790 nm to 810 nm. This means only a 20 nm change of pump results in 260 nm tunability of a mid-infrared soliton.     

脉冲内拉曼散射影响下的孤子之间的相互作用及其控制

研究了脉冲内拉曼散射效应影响下的同相和反相相邻孤子脉冲之间的相互作用,分析了孤子之间的相互作用对定时抖动的影响和脉冲内拉曼散射效应对孤子频移的影响。研究结果表明:在脉冲内,在拉曼散射效应的影响下,同相基态孤子脉冲的周期性离合被破坏了,两孤子脉冲一次碰撞后一直处于排斥状态,并且在碰撞后自频移现象十分明显;反相孤子脉冲的影响则较弱,两孤子脉冲都向下降沿发生偏移。引入非线性增益可以有效地控制孤子之间的相互作用,抑制自频移效应和稳定孤子传输。     

拉曼效应与光孤子通信

光纤孤子通信是一种非线性全光通信,它克服了光纤色散和电子设备响应速度慢等缺点,具有不损失波形,不改变速度,保真度高等优点。在光孤子通信中,一些重要问题是由 Raman 效应来解决的。如光纤受激 Raman 放大是根据光纤中的受激 Raman 效应对光孤子进行能量补偿。本文较为系统地介绍 Raman 效应与光孤子通信。     

Soliton Propagation near Zero-Dispersion Wavelength in Birefringence Fiber

fiom coupled nonlinear Schrodinger equation which describes the birefringence near zero-dispersion wavelength, we derive the evolution feature of soliton parameters and get the differential equation describing the evolution of interval between solitons along with propagation distance. At the same time, we have made detailed numerical research on the propagation in dissipation system of standard fundamental soliton. The result shows that for attractive potential, the distance of oscillation increases dong with the loss increases. For repulsive potential, the distance of oscillation diverges faster along with the loss increases. If selecting the proper-optical fiber of high-order dispersion, the interaction between solitons in birefringence fiber can be eliminated.     

Soliton Transmission Research on using Dispersion Step Fiber Chain Instead of Soliton Fiber

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利用拉曼孤子实现宽带拉曼脉冲压缩

从拉曼散射方程的出发,研究了利用拉曼孤子实现宽带拉曼脉冲压缩的机制,发现孤子脉冲的宽度随拉曼增益的增加减小,并与 运光的脉冲形状及相位结构有关。实验中利用ＸｅＣｌ激光／Ｈ２系统初步实现了５０％的压缩率,并将实验结果与理论进行了比较。     

Adiabatic Soliton Compresion in an Exponentially Dispersion-Decreasing Fiber Amplifier

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Fiber optic data busses for aircraft

Abstract

A variety of fiber optic data busses is being developed for aircraft applications. This article addresses five different data busses under consideration for both military and commercial aircraft. The impact of data bus protocol on component design, the effect of data bus topology on power budget and installation issues, and overall data bus performance are discussed.