IEC 62614-1:2020 pdf free download

IEC 62614-1:2020 pdf free download Fibre optics – Multimode launch conditions – Part 1: Launch condition requirements for measuring multimode attenuation
scope
This part of IEC 62614 describes the launch condition requirements used for measuringmultimode attenuation in passive components and in installed cable plants.
In this document, the fibre types that are addressed include category A1-OMx, where x = 2,3,4 and 5 (50 um/125 um), and A1-OM1(62,5 um/125 um)multimode fibres, as specified inIEC 60793-2-10. The nominal test wavelengths detailed are 850 nm and 1 300 nm. Thisdocument can be suitable for multimode attenuation measurements for other multimodecategories and/or other wavelengths, but the source condition for other categories andwavelengths are not defined here.
The purpose of these requirements is as follows:
. to ensure consistency of field measurements when different types of test equipment areused;
to ensure consistency of factory measurements when different types of test equipment areused;
to ensure consistency of field measurements when compared with factory measurements.
This document describes launch condition requirements for optical attenuation using sourceswith a controlled encircled flux(EF).
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies.
For undated references，the latestedition of the referenced document(including anyamendments) applies.
IEC 61280-1-4，Fibre optic communication subsystem test procedures – Part 1-4:Generalcommunication subsystems – Light source encircled flux measurement method
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.
IsO and IEC maintain terminological databases for use in standardization at the followingaddresses:
IEC Electropedia: available at http://www.electropedia.orgl
ISo online browsing platform: available at http://www.iso.org/obp
4 Background on multimode launch conditions
There have been a wide range of launch conditions used for testing multimode fibre components and systems. Light sources, typically used in measuring attenuation, can produce varying modal distributions when launched into multimode fibre. These differing modal distributions, combined with the differential mode attenuation (DMA) inherent in most multimode components, commonly cause measurement variations when measuring attenuation of multimode components. For example, attenuation measurement variations can occur when two similar light sources or different launch cords are used.
Legacy (LED based) applications had a wide power budget, which in most cases masked the variance in results between the factory and field measurement. As technology has evolved, the system requirements for attenuation have become more stringent. Demanding application requirements are driving the need for accurate and reproducible multimode attenuation measurements over a variety of field-test instruments. Attenuation measurement experiments, with different instruments having the same standards compliant set up, produce measurement variations that are induced by their differing launch conditions.