IEC 61280-4-4-2006 纤维光学通信子系统基本试验程序.第4-4部分:已安装链路的偏振模式色散测量

标准号：IEC 61280-4-4-2006
中文标准名称：纤维光学通信子系统基本试验程序.第4-4部分:已安装链路的偏振模式色散测量
英文标准名称：Fibre optic communication subsystem test procedures - Part 4-4: Cable plants and links - Polarization mode dispersion measurement for installed links
标准类型：M33
发布日期：1999/12/31 12:00:00
实施日期：1999/12/31 12:00:00
中国标准分类号：M33
国际标准分类号：33.180.01
适用范围：This part of IEC 61280 provides uniform methods of measuring polarization mode dispersion(PMD) of single-mode installed links. An installed link is the optical path between transmitterand receiver, or a portion of that optical path. These measurements may be used to assessthe suitability of a given link for high bit rate applications or to provide insight on therelationships of various related transmission attributes. The principles of this document arealigned with those of the optical fibre and optical fibre cable test method, IEC 60793-1-48 (seeBibliography), which focuses on aspects related to the measurement of factory lengths.Instead, this document focuses on the measurement methods and requirements for measuringlong lengths that might be installed – and that might also include other optical elements, suchas amplifiers, DWDM components, multiplexers, etc.PMD is a statistical parameter. The reproducibility of measurements depends on the particularmethod, but is limited also by the PMD level of the link. Gisin [3]5) derived a theoretical limit tothis reproducibility, by assuming an infinite range of measured wavelengths and idealmeasurement conditions.NOTE 1 Test methods for factory lengths of optical fibres and optical fibre cables are given in IEC 60793-1-48.NOTE 2 Test methods for optical amplifiers are given in IEC 61290-11-1 and IEC 61290-11-2.NOTE 3 Test methods for passive optical components are given in IEC 61300-3-32.NOTE 4 Guidelines for the calculation of PMD for links that include components such as dispersion compensatorsor optical amplifiers are given in IEC 61282-3.With the exception of Method D, all methods in this document may be used to measure thePMD in the gain band of links that include pumped optical amplifiers. For these links,amplified spontaneous emission (ASE) noise can generate depolarized spectral energy in theneighbourhood of the measurement wavelength. This will, in general, reduce the accuracy ofthe measurement. For Methods A, B, C, E and F, this effect can be moderated byimplementing an optical or electrical filter at the receive end. However, optical filtering will notremove the ASE right under the signal spectrum. The accuracy will then be limited by a lowerdegree of polarization (DOP), if the spectral width of the filter cannot be sufficiently reducedas with a broadband source. Lower DOP may require the signal to be integrated longer to bemeaningful or the result will become too noisy and interpretation will be erroneous.None of the methods is suitable for measuring the PMD of links with polarization dependentloss (PDL) in excess of 10 dB. Links with PDL values less than 1 dB can be measured withreasonable accuracy. Measurement accuracy may be compromised by the presence of PDL inexcess of 1 dB.