BS EN 61300-2-43:2014 BSI Standards Publication Fibre optic interconnecting devices and passive components — Basic test and measurement procedures Part 2-43: Tests — Screen testing of return loss of single-mode PC optical fibre connectors BRITISH STANDARD BS EN 61300-2-43:2014 National foreword This British Standard is the UK implementation of EN 61300-2-43:2014 It is identical to IEC 61300-2-43:2014 It supersedes BS EN 61300-2-43:2000 which is withdrawn The UK participation in its preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/2, Fibre optic interconnecting devices and passive components A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2014 Published by BSI Standards Limited 2014 ISBN 978 580 80875 ICS 33.180.20 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2014 Amendments/corrigenda issued since publication Date Text affected EUROPEAN STANDARD EN 61300-2-43 NORME EUROPÉENNE EUROPÄISCHE NORM September 2014 ICS 33.180.20 Supersedes EN 61300-2-43:1999 English Version Fibre optic interconnecting devices and passive components Basic test and measurement procedures - Part 2-43: Tests Screen testing of return loss of single-mode PC optical fibre connectors (IEC 61300-2-43:2014) Dispositifs d'interconnexion et composants passifs fibres optiques - Procédures fondamentales d'essais et de mesures - Partie 2-43: Essais - Sélection des connecteurs PC pour fibres optiques unimodales en fonction de leur affaiblissement de réflexion (CEI 61300-2-43:2014) Lichtwellenleiter - Verbindungselemente und passive Bauteile -Grundlegende Prüf- und Messverfahren Teil 2-43: Prüfungen - Verfahren zur Sortierprüfung von Einmoden-PC-LWL-Steckverbindern in Abhängigkeit von der Rückflussdämpfung (IEC 61300-2-43:2014) This European Standard was approved by CENELEC on 2014-07-24 CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels © 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members Ref No EN 61300-2-43:2014 E BS EN 61300-2-43:2014 EN 61300-2-43:2014 -2- Foreword The text of document 86B/3669/CDV, future edition of IEC 61300-2-43, prepared by SC 86B "Fibre optic interconnecting devices and passive components" of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61300-2-43:2014 The following dates are fixed: – latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2015-04-24 – latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2015-07-24 This document supersedes EN 61300-2-43:1999 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights Endorsement notice The text of the International Standard IEC 61300-2-43:2014 was approved by CENELEC as a European Standard without any modification In the official version, for Bibliography, the following note has to be added for the standard indicated : IEC 61300-1 NOTE Harmonized as EN 61300-1 -3- BS EN 61300-2-43:2014 EN 61300-2-43:2014 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies NOTE When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies NOTE Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu Publication Year Title EN/HD Year IEC 61300-3-6 - Fibre optic interconnecting devices and passive components - Basic test and measurement procedures Part 3-6: Examinations and measurements - Return loss EN 61300-3-6 - –2– BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 CONTENTS Scope Normative references General description Apparatus 5 Procedure 5.1 Selection of the reflection standard cord 5.2 Cord screen testing 5.3 Pigtail cord screen testing 6 Details to be specified Annex A (informative) Screen testing of return loss of pigtails having PC fibre optic connector Bibliography 13 Figure – Measurement set-up for open plug reflection standard Figure – Measurement set-up for mated reflection standard cords Figure – Measurement set-up for cord screen testing Figure – Measurement set-up for pigtail cord screen testing Figure A.1 – Measurement set-up of the screen test method Figure A.2 – Relationship between ß and α 10 Figure A.3 – Cumulative probability of return loss before test 11 Figure A.4 – Cumulative probability of return loss after test 11 Figure A.5 – Relationship between power and α 12 Figure A.6 – Measurement set-up of the reflected powers 12 BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 –5– FIBRE OPTIC INTERCONNECTING DEVICES AND PASSIVE COMPONENTS – BASIC TEST AND MEASUREMENT PROCEDURES – Part 2-43: Tests – Screen testing of return loss of single-mode PC optical fibre connectors Scope This part of IEC 61300 aims at screening single-mode physical contact (PC) optical fibre connectors of an optical fibre cord or an optical fibre pigtail in terms of return loss, thus ensuring minimum return loss when the connectors, which have been screen tested by this method, are randomly mated with each other in the field Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies IEC 61300-3-6, Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 3-6: Examinations and measurements – Return loss General description The domed ferrule end faces of PC connectors (not angled) are produced by a polishing process This polishing process results in a thin damaged layer at the fibre end face of the connector In silica fibres, the refractive index of the damaged layer is slightly higher than that of original fibre This high refractive index layer generates optical reflection When PC connectors are mated, return loss occurs as a result of multiple reflections at the two damaged layers of the butted connectors This test procedure ensures that a designed minimum return loss is achieved when PC connectors are randomly mated It screens cords or pigtails by using a pair of reflection standard plug (RP) cords The pair of reflection standard plugs is selected on the condition that the return loss when the plugs are mated is several decibels better than the designed minimum return loss Cords which pass this test will achieve the designed minimum return loss in over 99 % of cases when randomly mated (see Annex A) Apparatus The equipment listed below shall be chosen according to the method used to measure the connector return loss, in accordance with IEC 61300-3-6 The reflection standard plug shall be prepared according to the procedure given in 5.1 • Sources S • Excitation unit E • Detector D • Temporary joint TJ • Terminator T • Branching device BD • Reflection standard cord BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 –6– The reflection standard cord has a reflection standard plug (RP) at one end The other end of the reflection standard cord is an end or a plug whose return loss is better than the designed minimum return loss L rs (in decibels) 5.1 Procedure Selection of the reflection standard cord The reflection standard plug (RP) shall be selected by the following procedure a) Set up an objective reflection standard cord as shown in Figure S E TJ BD RP D 14,7 dB IEC 2022/14 Figure – Measurement set-up for open plug reflection standard b) Set the detector to 14,7 dB as the Fresnel reflection between the air and the silica fibre core as shown in Figure The refractive index of air is 1,0, and the one of silica fibre is 1,452 for single-mode fibre on condition ∆ = 0,3 %, λ = 1,31 µm NOTE Measurement accuracy can be improved by using the actual parameters of fibres which have been employed c) Connect another objective reflection standard cord as shown in Figure 2, then measure the return loss S E TJ BD TT RP D RP RP L rs + β (in decibels) IEC 2023/14 Figure – Measurement set-up for mated reflection standard cords d) Take the pair of objective reflection standard cords as reflection standard cords on condition that their return loss from the mating point is L rs + β (in decibels), where L rs is a designed minimum return loss The value of β shall be set at above dB 5.2 Cord screen testing a) Connect the device under test (DUT) (cord) between the reflection standard plugs as shown in Figure TJ S E BD DUT RP D TT RP L r (in decibels) IEC 2024/14 Figure – Measurement set-up for cord screen testing b) Measure the return loss L r (in decibels) from the two PC mating points c) Consider the objective cord as a screen tested cord when L r is greater than L rs 5.3 Pigtail cord screen testing a) Connect the objective PC connector of DUT (pigtail cord) to one reflection standard plug as shown in Figure 4, and terminate pigtail fibre end BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 S E –7– BD TJ DUT TT RP D L rs + α (in decibels) IEC 2025/14 Figure – Measurement set-up for pigtail cord screen testing b) Measure the return loss L r (in decibels) from the mating point c) Pass the objective pigtail cord as a screen tested cord when L r is greater than L rs + α (in decibels) The value of α shall be set at above 0,6 dB and at less than dB Details to be specified The following details, as applicable, shall be specified in the relevant specification: – minimum return loss L rs (in decibels); – condition of standard reflection plugs (the value of β in decibels); – screening condition for pigtail cords (the value of α in decibels); – attenuation of mating points between the reflection standard connectors and the objective connectors; – measurement uncertainty –8– BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 Annex A (informative) Screen testing of return loss of pigtails having PC fibre optic connector This annex describes the theoretical background of the screen testing of return loss for pigtails The basic idea is the same as the screen testing of return loss of cords having PC fibre optic connectors: select a pair of reference connectors, and a measurement pigtail is screen tested using the reference connector under a condition which is determined by simulation, where the distribution of high refractive index layer caused by polishing process is considered Two parameters β and α are introduced into this method Parameter β is used for the selection of a pair of reference connectors Parameter α is used as a criterion for screen testing measurement connectors These two parameters β and α are carefully determined by simulation so that return loss of mating point exceeds certain specified return loss L rs with high probability when the screen tested connectors are randomly connected The method assumes: – refractive index of fibre core n is 1,452; – refractive index of air n is 1,0 The set-up of the measurement and test procedures will be shown first Figure A.1 shows the set-up with the reference cords and 2; 1a and 2a represent reference connectors Points 3a and 3b are the connectors of the cord under test and 4a is the connector of the pigtail under test The connectors represented by 1b and 2b and 5b are angled connectors with high return loss S is the optical source, D is the optical detector and BD represents the optical coupler T is a fibre termination which shall have a high return loss; it should be made by the application of an index matching material to the fibre end or introducing an high attenuation in the fibre, for example, with a mandrel wrap BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 –9– P0 S BD 5b Reference cord 1a 1b P8 D Reference cord Adapter Reference cord 2a 2b P1 Adapter Reference cord Adapter Cord under test 3a Reference cord 3b 2a P2 Adapter Reference cord Pigtail under test T 4a P3 IEC 2026/14 Figure A.1 – Measurement set-up of the screen test method P0 is the input power and P8, P1, P2 and P3 are the reflected powers The symbols , , , indicate connection conditions The procedure of the screen test method is as follows: a) A pair of reference plugs is selected – Connect the connector 1b to the connector 5b, then measure the power P8 (see in Figure A.1) – Connect the reference connector 2a to the reference connector 1a, then measure the power P1 (see in Figure A.1) The condition of selection is given by: L rs < –10 log P1/P0 ≤ L rs + β (dB) (A.1) The measured power P0 can be described using P8, n and n as follows: –10 log 1/P0 = –10 log 1/P8 – 20 log (n – n ) / (n + n ) (A.2) The second term of the right side represents Fresnel reflection of air, and equals 14,7 dB Therefore Equation (A.1) can be rewritten as: < –10 log P1/P8 + 14,7 – L rs ≤ β (A.3) b) The cord under test is screen tested using the pair of reference connectors – Connect the cord under test between the reference connectors 1a and 2a, then measure the power P2 (see in Figure A.1) BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 – 10 – The criteria for the screen test of the measurement connectors are given by: –10 log P2/P8 + 14,7 ≥ L rs + α (dB) (A.4) c) The pigtail under test is screen tested using one of the pair reference connectors – Remove the reference connector 2a from reference connector 1a – Connect measurement connector 4a to the reference connector 1a, then measure the power P3 (see in Figure A.1) The criteria for the screen test of the measurement connectors is given by: –10 log P3/P8 + 14,7 ≥ L rs + α (dB) (A.5) The parameters β and α are determined by simulation so that the return loss of mating point exceeds the specified return loss L rs with high probability when the screen tested connectors are randomly connected Figure A.2 shows the relation between β and α derived by the condition that the return loss at the mating point exceeds a specified value L rs with a probability of 99 % The white circles represent the simulation results for pigtails The black circles represent those for cords The lines indicate first-order regression lines The figure indicates that the return loss of randomly concatenated cords exceeds L rs (in decibels) with a probability of 99 % under the condition of α ≥ 0,4 β – 2,0 The parameters β and α shall be determined according to this condition α (dB) α = 0,45 β − 0,3 Cord −2 Pigtail α = 0,4 β − 2,0 −4 −4 −2 β (dB) IEC 2027/14 Figure A.2 – Relationship between ß and α Figure A.3 shows the cumulative probability of return loss before screen testing Figure A.4 shows the cumulative probability of return loss when pigtails were screen tested under the condition of Equation (A.5) using the reference cord selected in accordance with Equation (A.1) The parameters L rs , β and α are set at 45 dB, dB and dB, respectively For pigtails, the probability exceeds 99 % when the return loss L rs is greater than 45 dB BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 – 11 – Cumulative probability (%) 100 1 0,1 35 40 45 50 55 Return loss 60 65 (dB) IEC 2028/14 Figure A.3 – Cumulative probability of return loss before test Cumulative probability (%) 100 β = 5, α = 1 35 40 45 50 Return loss 55 60 65 (dB) IEC 2029/14 Figure A.4 – Cumulative probability of return loss after test It is also important for the screen testing of pigtails that the fibre surface condition of one of the paired reference connectors is almost equal to that of the other reference connector Figure A.5 shows the relation of the difference of P4 and P5 and difference of α a and α b P4 and P5 are the reflected power of the paired reference connectors The power is measured in the way described in Figure A.6 where the meaning of the symbols is the same as in Figure A.1 The parameters α a and α b are individual criteria which mean that the return loss of randomly concatenated connectors selected using the individual reference connector exceeds a specified value L rs with a probability of 99 % under following condition: –10 log P2/P8 + 14,7 ≥ L rs + α a (dB); or –10 log P2/P8 + 14,7 ≥ L rs + α b (dB) Figure A.5 shows that the fibre surface condition of the reference connector 1a is almost equal to that of the reference connector 2a when the difference between the measured power P4 and P5 is small The power P4 and P5 shall satisfy the following condition to obtain the small difference between α a and α b within 1,0 dB: 2,0 (dB) ≥ | –10 log P4/P5 | (A.6) BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 – 12 – α a − α b (dB) 0 10 −10 log 15 P4 P5 20 (dB) IEC 2030/14 Figure A.5 – Relationship between power and α Reference cord S BD 5b T 1b 1a P4 D Reference cord 2 T 2b 2a P5 Reference cord Adapter Pigtail under test T 4a P2 Reference cord Adapter Pigtail under test T 4a P2 IEC 2031/14 Figure A.6 – Measurement set-up of the reflected powers BS EN 61300-2-43:2014 IEC 61300-2-43:2014 © IEC 2014 – 13 – Bibliography IEC 61300-1, Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 1: General and guidance _ This page deliberately left blank This page deliberately left blank NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards Institution (BSI) BSI is the national body responsible for preparing British Standards and other standards-related publications, information and services BSI is incorporated by Royal Charter British Standards and other standardization products are published by BSI Standards Limited About us Revisions We bring together business, industry, government, consumers, innovators and others to shape their combined experience and expertise into standards -based solutions Our British Standards and other publications are updated by amendment or revision The knowledge 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