共查询到20条相似文献,搜索用时 15 毫秒
1.
For optical fibers exhibiting a radially symmetric refractive index profile, there exists an analytical relation that connects waveguide dispersion and the Petermann-II mode field radius. We extend the usefulness of this relation to the nonradially symmetric case of microstructure fibers in the anomalous dispersion regime, yielding a simple relation between dispersion and effective mode field area. Assuming a Gaussian mode distribution, we derive a fundamental upper limit for the effective mode field area that is required to obtain a certain amount of anomalous waveguide dispersion. This relation is demonstrated to show excellent agreement for fiber designs suited for supercontinuum generation and soliton lasers in the near infrared. 相似文献
2.
Group-velocity dispersion in photonic crystal fibers 总被引:12,自引:0,他引:12
The dispersion properties of photonic crystal fibers are calculated by expression of the modal field as a sum of localized orthogonal functions. Even simple designs of these fibers can yield zero dispersion at wavelengths shorter than 1.27 mum when the fibers are single mode, or a large normal dispersion that is suitable for dispersion compensation at 1.55 mum. 相似文献
3.
以新型光学聚合物Topas 环烯烃共聚物(折射率为1.53)为基质,设计了四种微结构聚合物光纤.应用有限元方法对各种光纤在波长0.5—2.0 μm范围内的基模有效折射率、模场面积和数值孔径进行了计算.研究了结构参数对模场分布、单模特性和色散特性的影响.得出了具有极大/小模场面积、无限单模传输和平坦近零色散的光纤结构参数.与石英、聚甲基丙烯酸甲酯基质的微结构光纤相比,该光纤具有更大的数值孔径和较宽的平坦近零色散范围.为光纤的制备提供了理论指导.
关键词:
微结构聚合物光纤
有限元方法
传输特性
Topas 环烯烃共聚物 相似文献
4.
Jing Huang 《Optik》2011,122(15):1376-1380
The small signal analysis method is presented for the discussion of amplified spontaneous emission (ASE) noise in dispersion and nonlinear transmission fibers in wavelength division multiplex (WDM) systems. Based on it, the complete ASE noise spectra (include the ASE noise, the ASE noise enhanced by parametric gain and the crosstalk caused by ASE noise and parametric gain) are described and the factors impacting on them are discussed. The crosstalk caused by ASE noise and parametric gain in single mode fibers, non-zero dispersion shift fibers and dispersion compensation fibers are analyzed. Taking into account the dispersion effect in the transmission fibers, the three types of ASE noise may decrease. 相似文献
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Weicheng Chen Wencheng Xu Zhanqiang Liang Aiping Luo Hu Cui Dingan Han Libing Chen Hong Lu 《Optics & Laser Technology》2007,39(4):696-700
We propose a new method to strengthen the nonlinear pulses robustness to polarization mode dispersion through modulating the breath oscillation behavior of two principal polarization components of optical pulses. The optical realization of the breath behavior modulation is based on the degenerate four-wave mixing effect in fibers with high birefringence. The breath intensity increases and the periodical breath oscillation distances shorten in the process of breath behavior modulation. It is proved that the breath-modulated pulses have stronger adaptive abilities to polarization mode dispersion than common solitons when propagating in conventional single-mode fibers with random birefringence. 相似文献
7.
Asymptotic analysis of Bragg fibers 总被引:1,自引:0,他引:1
Using an asymptotic analysis, we obtain an eigenvalue equation for the general mode dispersion in Bragg fibers. The asymptotic analysis is applied to calculate the dispersion relation and the field distribution of TE modes in a Bragg fiber. We compare the asymptotic results with exact solutions and find excellent agreement between them. This asymptotic approach greatly simplifies the analysis and design of Bragg fibers. 相似文献
8.
In this paper, the dispersion managed soliton (DMS) transmission equation is built on considering the effects of polarization mode dispersion (PMD) and filter control. The DMS transmission of filtering control in constant birefringence fibers is firstly analyzed by varitional method, from which the evolving rules of characteristical DMS parameters are obtained. Secondly, the stability of DMS transmission and its timing jitter are investigated in the random varying birefringence fibers with the conventional model of PMD. The results reveal that filter control DMS system has powerful robustness to PMD effects and DMS's timing jitter can be decreased considerably with the help of filters. 相似文献
9.
Study of the frequency autocorrelation of the differential group delay in fibers with polarization mode dispersion 总被引:1,自引:0,他引:1
We study the frequency autocorrelation of the differential group delay (DGD) in fibers with polarization mode dispersion (PMD). We show that the correlation bandwidth of the DGD is comparable with that of the orientation of the PMD vector. Furthermore, we show that all the most general statistical properties of polarization mode dispersion in long fibers are uniquely determined by the mean DGD. An estimate of the accuracy of measurements in which the mean DGD is extracted by frequency averaging in a single fiber is obtained as a function of the measured bandwidth. 相似文献
10.
塑料光纤的微分模延迟数据对研究塑料光纤的色散特性具有非常重要的意义。采用频域相移法测量了不同长度的两种折射率分布塑料光纤:阶跃型塑料光纤(SI—POF)和渐变型塑料光纤(GI—POF)的微分模延迟曲线。实验结果表明,由于短光纤可以忽略模式耦合和模式损耗,1m塑料光纤的微分模延迟测量值与理论计算值吻合得非常好。因此,频域相移法可以简单、方便、精确地测量塑料光纤的微分模延迟。此外,通过比较不同长度塑料光纤的微分模延迟曲线的变化,可在一定程度上分析光纤中存在的模式耦合。 相似文献
11.
光纤的模场分布是光纤最基本的特性,它包含了很多光纤的有关信息,单模光纤都工作在不可见的近红外波长范围内,且在可见光范围并非单模工作。提出了一种利用可见光测量近红外单模光纤模场直径的新方法,导出了一个考虑光纤材料色散的更精确地计算不同V值时模场直径的公式,设计了利用可见光直接拍摄模斑的系统,采用缠绕法提取基模,消除了高阶模对测量结果的影响,利用二元非线性曲面拟合,测得了光纤在近红外工作波长下的模场直径。由于无需红外光源、红外探测器以及精密的扫描装置,该方法具有成本低廉、测量速度快、调整容易等优点。 相似文献
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We study the properties of polarization evolution in sinusoidally spun fibers. It is found that, similar to linear birefringent fibers, the evolution of the state of polarization exhibits periodicity, which can be measured by distributed measurement, such as those made with a polarization optical time domain reflectometer. The spatial period is linked with the spin parameters and fiber beat length in a simple equation. In combination with a previous finding, it is shown that the spatial period is uniquely related to spun-fiber polarization mode dispersion. This suggests that distributed fiber polarization mode dispersion can be determined throughthe measurement of the spatial period obtained in a distributed measurement. 相似文献
15.
We propose a full-vectorial Galerkin method for the analysis of circular symmetric fibers with arbitrary index profiles. A set of orthogonal Laguerre-Gauss functions is used to calculate the dispersion relation and mode fields of TE and TM modes. Examples are given for both standard step-index fibers and Bragg fibers. For standard step-index fiber with low or high index contrast, the Galerkin method agrees well with the analytical results. In the case of the TE mode of a Bragg fiber it agrees well with the asymptotic results. 相似文献
16.
S. P. N. Cani C. A. De Francisco D. H. Spadoti V. E. Nascimento B.-H. V. Borges L. C. Calmon M. A. Romero 《Fiber and Integrated Optics》2007,26(5):255-270
The design and performance of microstructured optical fibers (MOFs) for simultaneous dispersion compensation and Raman amplification is numerically investigated. We studied a lumped Raman amplifier designed to compensate the signal loss and dispersion introduced by a 100-km, 16-channel C-band WDM link. The impairments induced by the nonlinearities caused by the small mode area of the designed MOF are investigated and the analysis is extended to include non-ideal factors such as excess background losses, splice loss, and the geometry variations during the fabrication process. The results are discussed and compared to those obtained for conventional dispersion compensating fibers (DCFs). 相似文献
17.
A phase-sensitive optical low-coherence reflectometry (OLCR) technique is demonstrated to simultaneously measure the absolute chromatic dispersion values of each guided LP mode of a few-mode fiber. We show that the OLCR technique requires only short samples of fiber (<1 m) and has no need for high-ratio mode converters to reach an accurate wavelength-dependent group delay evolution of every mode. As an example we present for the first time to our knowledge a direct and complete analysis of few-mode fibers with high, low, positive, and negative modal dispersion values, leading to chromatic dispersion parameters in good agreement with theoretical predictions. 相似文献
18.
Ying Liu Jingyuan Wang Yuquan Li Rong Wang Jianhua Li Xiaogang Xie 《Optics & Laser Technology》2012,44(7):2076-2079
A novel dispersion compensating fiber (DCF) with multiple windows is proposed, which is based on hybrid photonic crystal fibers. This type of DCF has a characteristic of multiple negative dispersion windows by the coupling between the hybrid guiding mode in the boundary of each band-gap of the core region and the index guiding mode in the cladding defect area. This is entirely different from the ordinary dual-core mechanism. The proposed DCF can compensate multiple dispersion wavelengths at the same time. 相似文献
19.
报道了利用800nm飞秒激光脉冲在多孔微结构光纤中产生超连续谱展宽的现象,连续谱展宽范围为440—890nm.基于标量波近似理论对微结构光纤包层的有效折射率和基模的有效面积以及光纤的色散特性进行了计算,发现微结构光纤具有特殊的控制色散和波导特性的能力,对超连续谱展宽的机理进行了初步解释.本文的理论分析和实验结果有较好的一致性,认为即使包层由无序填充气线组成的多孔微结构光纤也可以出现超连续谱展宽效应.
关键词:
多孔微结构光纤
超连续谱
有效折射率
色散 相似文献
20.
T. Kato M. Hirano T. Fujii T. Yokokawa Y. Yamamoto M. Onishi 《Journal of Optical and Fiber Communications Reports》2007,4(2):86-109
Design optimization of dispersion compensating fibers (DCFs) based on the fundamental mode is described considering the packaging
technique. Optical performances of the DCF modules are mainly limited by the macro-, micro-bending loss and the polarization
mode dispersion that strongly depend on the module structure. Two types of DCF modules are demonstrated as examples. Bobbin-less
module structure that mitigates the bending limit is also described. 相似文献