单模光纤有效面积测量指南

[中文适用范围]： IEC TR 62284:2025 是一份技术报告，适用于单模光纤。其目的是记录测量这些光纤有效面积（Aeff）的方法。该报告定义了三种测量Aeff的方法。所有方法共有的信息可在本文正文中找到，而每种方法特有的信息则在附录中。三种方法分别为：a) 直接远场法（DFF）；b) 远场可变孔径法（VAMFF）；c) 近场法（NF）。用于解决争议的参考方法是方法A，即直接远场法。有效面积是单模光纤的一个光学属性，常用于系统设计中，尤其是在可能受非线性折射率系数n2影响的系统中。在国家和国际标准组织中，均对本文件中使用的定义达成一致。只要在实施中采用良好的工程实践，方法A、B和C提供的结果被认为是等效的。直接远场法被确定为参考方法，因为这是最直接的方法，并且在IEC 60793-1-45和ITU-T建议G.650.1中被指定为模式场直径的参考方法。映射函数是一种公式，通过该公式可将一个属性的测量结果用于预测同一光纤上另一个属性的值。对于特定类型的光纤和设计，模式场直径（MFD）（IEC 60793-1-45）可用来通过映射函数预测有效面积。映射函数特定于某种光纤类型和设计。映射函数是通过实验生成的，实验中选择一个光纤样本，以代表MFD值的范围，并对样本中的光纤同时测量MFD和Aeff。可以用线性回归来确定拟合系数k，如以下定义：注1：若其他数学模型在一般情况下更具准确性，也可使用。注2：有关更多信息，请参见附录E。本版取消并替代了2003年发布的首版。本版构成技术修订。与前一版相比，本版包含以下重大技术更改：a) 改进了对B-657光纤测量细节的描述；b) 修改了直接远场扫描中光纤末端与探测器之间的最小距离（附录A）；c) 删除了附录H。 [外文原描述]： IEC TR 62284:2025 which is a Technical Report, applies to single-mode optical fibres. Its object is to document the methods for measuring the effective area (Aeff) of these fibres. It defines three methods of measuring Aeff. Information common to all the methods is found in the body of this document. Information specific to each method is found in the annexes. The three methods are: a) direct far-field (DFF); b) variable aperture in the far-field (VAMFF); c) near-field (NF). The reference method, used to resolve disputes, is method A, direct far-field. Effective area is an optical attribute that is specified for single-mode fibres and used in system designs probably affected by the non-linear refractive index coefficient, n2. There is agreement in both national and international standards bodies concerning the definition used in this document. Methods A, B, and C have been recognised as providing equivalent results, provided that good engineering is used in implementation. The direct far-field is the reference method because it is the most direct method and is named as the reference method for mode field diameter in IEC 60793-1-45 and ITU-T Recommendation G.650.1. A mapping function is a formula by which the measured results of one attribute are used to predict the value of another attribute on a given fibre. For a given fibre type and design, the mode field diameter (MFD) (IEC 60793-1-45) can be used to predict the effective area with a mapping function. A mapping function is specific to a particular fibre type and design. Mapping functions are generated by doing an experiment in which a sample of fibre is chosen to represent the spectrum of values of MFD and in which the fibres in the sample are measured for both MFD and Aeff. Linear regression can be used to determine the fitting coefficient, k, as defined by the following: NOTE 1 Other mathematical models can be used if they are generally more accurate. NOTE 2 See Annex E for more information. This second edition cancels and replaces the first edition published in 2003. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) improvement of the description of measurement details for B-657 fibre; b) modification of the minimum distance between the fibre end and the detector for the direct far field scan (Annex A); c) deletion of Annex H.