標準號：BS EN 61280-4-4-2006
中文標準名稱：光纖通信子系統基本試驗程序.光纜設施和鏈路.已安裝鏈路的偏振模式色散測量
英文標準名稱：Fibre optic communication subsystem basic test procedures - Cable plants and links - Polarization mode dispersion measurement for installed links
標準類型：M33
發布日期：2006/5/31 12:00:00
實施日期：2006/5/31 12:00:00
中國標準分類號：M33
國際標準分類號：33.180.01
適用范圍：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.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.