1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ICS 33.180.20 ISBN 0-626-15224-0 SANS 61300-3-6:2004 Edition 2 IEC 61300-3-6:2003 Edition 2 SOUTH AFRICAN NATIONAL STANDARD Fibre optic interconnecting d
4、evices and passive components Basic test and measurement procedures Part 3-6: Examinations and measurements Return loss This national standard is the identical implementation of IEC 61300-3-6:2003 and is adopted with the permission of the International Electrotechnical Commission. Published by Stand
5、ards South Africa 1 dr lategan road groenkloof private bag x191 pretoria 0001 tel: 012 428 7911 fax: 012 344 1568 international code + 27 12 www.stansa.co.za Standards South Africa 2004 SANS 61300-3-6:2004 Edition 2 IEC 61300-3-6:2003 Edition 2 Table of changes Change No. Date Scope Abstract Provide
6、s procedures for the measurement of the return loss (RL) of the fibre optic device under test (DUT). Return loss (RL), as used in this standard, is the ratio of the power incident on, or entering, the DUT to the total power reflected by the DUT, expressed in decibels. Return loss is a positive numbe
7、r. Keywords fibre optic cables, fibre optic connectors, fibre optics, measuring techniques, optical communication systems, optical fibres. National foreword This South African standard was approved by National Committee STANSA SC 74A, Communication technology Fibre optics, in accordance with procedu
8、res of Standards South Africa, in compliance with annex 3 of the WTO/TBT agreement. This SANS edition cancels and replaces the first SABS edition (SABS IEC 61300-3-6:1997). INTERNATIONALSTANDARDIEC61300-3-6Second edition2003-02Fibre optic interconnecting devicesand passive components Basic test and
9、measurement procedures Part 3-6:Examinations and measurements Return lossDispositifs dinterconnexion et composants passifs fibres optiques Mthodes fondamentales dessais et de mesures Partie 3-6:Examens et mesures Puissance rflchie IEC 2003 Copyright - all rights reservedNo part of this publication m
10、ay be reproduced or utilized in any form or by any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the publisher.International Electrotechnical Commission, 3, rue de Varemb, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11
11、 Telefax: +41 22 919 03 00 E-mail: inmailiec.ch Web: www.iec.chMFor price, see current cataloguePRICE CODECommission Electrotechnique InternationaleInternational Electrotechnical Commission 2 61300-3-6 IEC:2003(E)CONTENTSFOREWORD 31 Scope 52 Normative references. 53 General description 53.1 Method 1
12、 63.2 Method 2 63.3 Method 3 63.4 Method 4 63.5 Selection of reference measurement method. 64 Apparatus and symbols 74.1 Device under test (DUT) 74.2 Method 1: measurements with OCWR. 74.3 Method 2: measurements with OTDR 94.4 Method 3: measurements with OLCR 94.5 Method 4: measurements with OFDR .1
13、15 Procedure .125.1 Launch conditions 125.2 Pre-conditioning.135.3 DUT output port .135.4 Method 1: measurement with OCWR135.5 Method 2: measurement with OTDR.175.6 Method 3: measurement with OLCR .205.7 Method 4: measurements with OFDR .206 Details to be specified.226.1 Return loss measurement with
14、 OCWR .226.2 Return loss measurement with OTDR.226.3 Return loss measurement with OLCR.236.4 Return loss measurement of with OFDR.236.5 Measurement procedure 24Annex A (informative) Comparison of return loss detectable by four different methods 25Figure 1 Measurement set-up of return loss OCWR metho
15、d. 7Figure 2 Measurement set-up of return loss with OTDR method . 9Figure 3 Measurement set-up of return loss with OLCR method 10Figure 4 Measurement set-up of return loss with OFDR method 11Figure 5 Measurement set-up of the system reflected power .14Figure 6 Measurement set-up of the branching dev
16、ice transfer coefficient .14Figure 7 Measurement set-up of the splitting ratio of the branching device 15Figure 8 Measurement set-up of return loss with an OCWR 15Figure 9 Typical OTDR trace of the response to a reflection17Figure A.1 Comparison of detectable return loss, resolution and measurable d
17、istancefor four return loss measurement methods.2561300-3-6 IEC:2003(E) 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION_FIBRE OPTIC INTERCONNECTING DEVICESAND PASSIVE COMPONENTS BASIC TEST AND MEASUREMENT PROCEDURES Part 3-6: Examinations and measurements Return lossFOREWORD1) The IEC (International Ele
18、ctrotechnical Commission) is a worldwide organization for standardization comprisingall national electrotechnical committees (IEC National Committees). The object of the IEC is to promoteinternational co-operation on all questions concerning standardization in the electrical and electronic fields. T
19、othis end and in addition to other activities, the IEC publishes International Standards. Their preparation isentrusted to technical committees; any IEC National Committee interested in the subject dealt with mayparticipate in this preparatory work. International, governmental and non-governmental o
20、rganizations liaisingwith the IEC also participate in this preparation. The IEC collaborates closely with the International Organizationfor Standardization (ISO) in accordance with conditions determined by agreement between the twoorganizations.2) The formal decisions or agreements of the IEC on tec
21、hnical matters express, as nearly as possible, aninternational consensus of opinion on the relevant subjects since each technical committee has representationfrom all interested National Committees.3) The documents produced have the form of recommendations for international use and are published in
22、the formof standards, technical specifications, technical reports or guides and they are accepted by the NationalCommittees in that sense.4) In order to promote international unification, IEC National Committees undertake to apply IEC InternationalStandards transparently to the maximum extent possib
23、le in their national and regional standards. Anydivergence between the IEC Standard and the corresponding national or regional standard shall be clearlyindicated in the latter.5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for anyequipment declar
24、ed to be in conformity with one of its standards.6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subjectof patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.International Standard IEC 61300-
25、3-6 has been prepared by subcommittee 86B: Fibre opticinterconnecting devices and passive components, of IEC technical committee 86: Fibre optics.This second edition cancels and replaces the first edition published in 1997 and itsamendments 1 (1998) and 2 (1999). This edition constitutes a technical
26、 revision.The text of this standard is based on the following documents:FDIS Report on voting86B/1778/FDIS 86B/1832/RVDFull information on the voting for the approval of this standard can be found in the report onvoting indicated in the above table.This publication has been drafted in accordance wit
27、h the ISO/IEC Directives, Part 2.IEC 61300 consists of the following parts, under the general title Fibre optic interconnectingdevices and passive components Basic test and measurement procedures: Part 1: General and guidance Part 2: Tests Part 3: Examinations and measurements 4 61300-3-6 IEC:2003(E
28、)The committee has decided that the contents of this publication will remain unchanged until2007. At this date, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended.A bilingual version of this publication may be issued at a later date.61300-3-6 IEC:2003(E) 5 FIBR
29、E OPTIC INTERCONNECTING DEVICESAND PASSIVE COMPONENTS BASIC TEST AND MEASUREMENT PROCEDURES Part 3-6: Examinations and measurements Return loss1 ScopeThis part of IEC 61300 presents procedures for the measurement of the return loss (RL) ofa fibre optic device under test (DUT). RL, as used in this st
30、andard, is the ratio of the power (Pi)incident on, or entering, the DUT to the total power reflected (Pr) by the DUT, expressedin decibels:=irlog10PPRL (1)Return loss is a positive number.2 Normative referencesThe following referenced documents are indispensable for the application of this document.
31、 Fordated references, only the edition cited applies. For undated references, the latest edition ofthe referenced document (including any amendments) applies.IEC 60793-2 (all parts), Optical fibres Product specificationsIEC 61300-1, Fibre optic interconnecting devices and passive components Basic te
32、st andmeasurement procedures Part 1: General and guidanceIEC 61300-3-1, Fibre optic interconnecting devices and passive components Basic test andmeasurement procedures Part 3-1: Examinations and measurements Visual examinationIEC 61300-3-39, Fibre optic interconnecting devices and passive components
33、 Basic test andmeasurement procedures Part 3-39: Examinations and measurements PC optical connectorreference plug selection3 General descriptionFour methods will be presented for measuring optical return loss: measurement with an optical continuous wave reflectometer (OCWR) (method 1); measurement w
34、ith an optical time domain reflectometer (OTDR) (method 2); measurement with an optical low coherence reflectometry (OLCR) (method 3); measurement with an optical frequency domain reflectometry (OFDR) (method 4).These four measurement methods have different characteristics and different applications
35、 interms of spatial resolution and detectable RL (in annex A a comparison of return lossdetectable by the four different methods is reported). 6 61300-3-6 IEC:2003(E)3.1 Method 1This technique is the nearest to the theoretical definition of return loss given by equation (1). Itmeasures directly the
36、incident power and the reflected power. It is not affected by instrumentaldata processing and it gives absolute measurement values, which are not relative to areference reflection (technique A). This method has some limiting factors: it cannot spatiallyresolve two different reflections on the line a
37、nd its dynamic range is limited by thecharacteristics of the branching device and by the ability to suppress the reflections beyond theone from the DUT.3.2 Method 2This method allows measurement of RL from reflection points on an optical line, with a spatialresolution in the metre range and with a d
38、ynamic range of more than 75 dB (depending on thepulse width) using an OTDR instrument.The OTDR measurement method is very suitable for field measurements where it is necessaryto measure RLs on long optical lines.3.3 Method 3The purpose of this method is to measure reflection profiles of single-mode
39、 optical devices witha micrometre spatial resolution and a high dynamic range (90 dB) by using optical low-coherence interference.The reflection profile is defined as a distribution of reflections at individual end-faces and/orconnected points in single-mode optical devices. When the reflection at a
40、 particular point isR (dB), the return loss at this point is given by R (dB). This method measures the reflection ata point by detecting the power of a beat signal produced by optical interference between thereflected light and the reference light. When a component with dispersed reflections isanaly
41、sed, each reflection can be identified and located, provided their separation is greaterthan the spatial resolution of the measurement system.3.4 Method 4The purpose of this procedure is to measure the return loss of single-mode optical devices witha spatial resolution in the centimetre range and hi
42、gh dynamic range (70 dB) by using opticalfrequency domain reflectometryOne of the prime benefits of this technique is the ability to spatially resolve the desiredreflection from undesired ones, such as all of the connectors or unterminated ports on theDUT, without any dead zone. Moreover, the OFDR m
43、ethod is highly reliable and the apparatuscan be compact.Measurement in the frequency domain is based on the ability to convert information in the timedomain by means of an inverse Fourier transform. In this way with a source modulated fromsome kHz to 1 GHz, it is possible to resolve two reflective
44、points on an optical line separatedby some centimetres.3.5 Selection of reference measurement methodDue to the different characteristics of these methods, and their different application fields, thereference method depends on the type of DUT. For a component with RL 55 dB the referenceis method 1, f
45、or a component with RL 55 dB the reference is method 2 using a pulse durationless than 100 ns. In cases in which it is necessary to resolve more reflection points separatedby a distance of less than 5 m, the reference shall be method 3.61300-3-6 IEC:2003(E) 7 4 Apparatus and symbols4.1 Device under
46、test (DUT)Where the DUT is the mounted connector on one end of a component, the reference matingplug shall be considered one-half of the DUT connection on the temporary joint (TJ) side andhave the same end-face finish and minimum performance as the connectors to be measured.Where the DUT is an entir
47、e component assembly terminated with pigtails with or withoutconnectors, reference plugs with pigtails and, as required, reference adapters are to be addedto those ports with connector terminations so as to form complete connector assemblies withpigtails. Reference mating plugs shall then be conside
48、red one-half of the TJ and have thesame end-face finish and minimum performance as the connectors to be measured. All unusedports shall be terminated as stated in 4.2.5.Unless otherwise specified, reference plugs shall meet IEC 61300-3-39. The referenceadapters shall meet the appropriate IEC connect
49、or interface dimensions and ensure a highdegree of repeatability and reproducibility. It is recommended that the test adapters be testedand visually inspected after every 100 matings and replaced after 500 matings.4.2 Method 1: measurements with OCWRT1PaPref.D1S1BDDUTTJ1D2IEC 030/03Figure 1 Measurement set-up of return loss OCWR methodThe circuit in Figure 1 is representative of, but is not the only, circuit that
