1、BSI Standards PublicationOptical fibresPart 1-42: Measurement methods and test procedures Chromatic dispersionBS EN 60793-1-42:2013National forewordThis British Standard is the UK implementation of EN 60793-1-42:2013. It isidentical to IEC 60793-1-42:2013. It supersedes BS EN 60793-1-42:2007which is
2、 withdrawn.The UK participation in its preparation was entrusted by Technical Com-mittee GEL/86, Fibre optics, to Subcommittee GEL/86/1, Optical fibres and cables.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to inc
3、lude all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 73741 1ICS 33.180.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This Bri
4、tish Standard was published under the authority of theStandards Policy and Strategy Committee on 31 July 2013.Amendments issued since publicationDate Text affectedBRITISH STANDARDBS EN 60793-1-42:2013EUROPEAN STANDARD EN 60793-1-42 NORME EUROPENNE EUROPISCHE NORM April 2013 CENELEC European Committe
5、e for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members
6、. Ref. No. EN 60793-1-42:2013 E ICS 33.180.10 Supersedes EN 60793-1-42:2007 English version Optical fibres - Part 1-42: Measurement methods and test procedures - Chromatic dispersion (IEC 60793-1-42:2013) Fibres optiques - Partie 1-42: Mthodes de mesure et procdures dessai - Dispersion chromatique (
7、CEI 60793-1-42:2013) Lichtwellenleiter - Teil 1-42: Messmethoden und Prfverfahren - Chromatische Dispersion (IEC 60793-1-42:2013) This European Standard was approved by CENELEC on 2013-02-28. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions
8、 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
9、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 nationa
10、l 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, Portug
11、al, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 60793-1-42:2013EN 60793-1-42:2013 - 2 - Foreword The text of document 86A/1419/CDV, future edition 3 of IEC 60793-1-42, prepared by SC 86A “Fibres and cables” of IEC/TC 86 “Fibre optics“ was submitted t
12、o the IEC-CENELEC parallel vote and approved by CENELEC as EN 60793-1-42:2013. 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) 2013-11-28 latest date by which the nationa
13、l standards conflicting with the document have to be withdrawn (dow) 2016-02-28 This document supersedes EN 60793-1-42:2007. EN 60793-1-42:2013 includes the following significant technical changes with respect to EN 60793 1-42:2007: a) the inclusion of category B6 single-mode fibres; b) the deletion
14、 of test method D (interferometry). This standard should be read in conjunction with EN 60793-1-1. 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 pa
15、tent rights. Endorsement notice The text of the International Standard IEC 60793-1-42:2013 was approved by CENELEC as a European Standard without any modification. BS EN 60793-1-42:2013- 3 - EN 60793-1-42:2013 Annex ZA (normative) Normative references to international publications with their corresp
16、onding 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
17、 amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60793-1-1 2008 Optical fibres - Part 1-1: Measurement methods and test procedures - General and guidance EN 60
18、793-1-1 2008 IEC 60793-1-41 - Optical fibres - Part 1-41: Measurement methods and test procedures - Bandwidth EN 60793-1-41 - IEC 60793-2 - Optical fibres - Part 2: Product specifications - General EN 60793-2 - BS EN 60793-1-42:2013 2 60793-1-42 IEC:2013 CONTENTS 1 Scope . 6 2 Normative references .
19、 7 3 Overview of methods 7 3.1 Method A, phase shift 7 3.2 Method B, spectral group delay in the time domain 7 3.3 Method C, differential phase shift 7 4 Reference test methods 8 4.1 Category A1 and sub-category A4f, A4g and A4h multimode fibres . 8 4.2 Class B single-mode fibres 8 5 Apparatus . 8 5
20、.1 General . 8 5.2 Launch optics 8 5.3 High-order mode filter (single-mode) . 8 5.4 Input positioning apparatus . 8 5.5 Output positioning apparatus . 8 5.6 Computation equipment . 9 6 Sampling and specimens 9 6.1 Specimen length 9 6.2 Specimen end face 9 6.3 Reference fibre 9 7 Procedure. 9 8 Calcu
21、lations . 9 8.1 General . 9 8.2 Category A1 and sub-category A4f, A4g, A4h multimode fibres and category B1.1, B1.3 and sub-category B6_a1 and B6_a2 single-mode fibres . 10 8.3 Category B1.2 single-mode fibres 10 8.4 Category B2 single-mode fibres . 10 8.5 Category B4 and B5 single-mode fibres . 11
22、9 Results . 11 9.1 Report the following information with each measurement: . 11 9.2 The following information shall be available upon request: 11 10 Specification information 11 Annex A (normative) Requirements specific to method A, phase-shift 12 Annex B (normative) Requirements specific to method
23、B, spectral group delay in the time domain 17 Annex C (normative) Requirements specific to method C, differential phase-shift 21 Annex D (normative) Chromatic dispersion fitting . 26 Bibliography 28 Figure A.1 Chromatic dispersion measurement set, multiple laser system (typical) 13 Figure A.2 Typica
24、l delay and dispersion curves 13 Figure A.3 Chromatic dispersion measurement set, LED system (typical) 15 Figure B.1 Block diagram, fibre Raman laser system . 18 Figure B.2 Block diagram, multiple laser diode system . 18 BS EN 60793-1-42:201360793-1-42 IEC:2013 3 Figure C.1 Chromatic differential ph
25、ase dispersion measurement set, multiple laser system 22 Figure C.2 Chromatic differential phase dispersion measurement set, LED system 23 Figure C.3 Chromatic dispersion measurement set, differential phase by dual wavelength method . 23 Figure C.4 Chromatic dispersion measurement set, differential
26、phase by double demodulation 24 Table D.1 Definition of fit types and fit coefficients; equations for group delay and dispersion coefficient 26 Table D.2 Slope equations . 26 Table D.3 Zero-dispersion wavelength and slope equations . 27 BS EN 60793-1-42:2013 6 60793-1-42 IEC:2013 OPTICAL FIBRES Part
27、 1-42: Measurement methods and test procedures Chromatic dispersion 1 Scope This part of IEC 60793 establishes uniform requirements for measuring the chromatic dispersion of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. Chromatic dispersion varies w
28、ith wavelength. Some methods and implementations measure the group delay as a function of wavelength and the chromatic dispersion and dispersion slope are deduced from the derivatives (with respect to wavelength) of this data. This differentiation is most often done after the data are fitted to a ma
29、thematical model. Other implementations can allow direct measurement (of the chromatic dispersion) at each of the required wavelengths. For some (sub-) categories of fibre, the chromatic dispersion attributes are specified with the parameters of a specific model. In these cases, the relevant recomme
30、ndation or standard defines the model appropriate for the definition of the specified parameters. For other fibre (sub-) categories, the dispersion is specified to be within a given range for one or more specified wavelength intervals. In the latter case, either direct measurements may be made at th
31、e wavelength extremes or some fitting model may be used to either allow group delay measurement methods or implementations, or to allow storage of a reduced set of parameters that may be used to calculate the interpolated dispersion for particular wavelengths which may not have actual direct measure
32、ment values. Annex D gives a general description of chromatic dispersion fitting and outlines a number of fitting equations suitable for use with any of the measurement methods or fibre categories. This standard gives three methods for measuring chromatic dispersion: method A: phase shift; method B:
33、 spectral group delay in the time domain; method C: differential phase shift. Methods A, B, and C apply to the measurement of chromatic dispersion of the following fibres from IEC 60793-2 over a specified wavelength range: category A1 graded-index multimode fibres; sub-category A4f, A4g and A4h mult
34、imode fibres; category B1, B2, B4, B5 and sub-categories B6_a1 and B6_a2 single-mode fibres. The methods can be applied to laboratory, factory and field measurements of chromatic dispersion, and the wavelength range of the measurements can be tailored as required. Measurements are made at temperatur
35、e as stated in Table 1 of IEC 60793-1-1:2008, Standard range of atmospheric conditions. The methods are suitable for fibre or cable lengths greater than 1 km. They may also be applied to shorter lengths, but accuracy and repeatability may be compromised. Information common to all methods is containe
36、d in Clauses 1 to 8, and information pertaining to each individual method appears in Annexes A, B and C, respectively. BS EN 60793-1-42:201360793-1-42 IEC:2013 7 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for
37、 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 60793-1-1:2008, Optical fibres Part 1-1: Measurement methods and test procedures General and guidance IEC 60793-1-41,
38、Optical fibres Part 1-41: Measurement methods and test procedures Bandwidth IEC 60793-2, Optical fibres Part 2: Product specifications General 3 Overview of methods 3.1 Method A, phase shift This method describes a procedure for determining the chromatic dispersion of the categories of class B singl
39、e-mode fibres B1, B2, B4, B5 and sub-categories B6_a1 and B6_a2, category A1 graded-index multimode fibres and sub-category A4f, A4g and A4h fibres, over a specified wavelength range using the relative phase shifts among sinusoidally modulated optical sources of different wavelengths. The sources ar
40、e typically laser diodes or filtered light emitting diodes or filtered amplified spontaneous emission (ASE) sources. Relative phase shifts are converted to relative time delays, and the resultant spectral group delay data are then fitted to an equation defined for each fibre (sub) category. 3.2 Meth
41、od B, spectral group delay in the time domain This method describes a procedure for determining the chromatic dispersion of the categories of class B single-mode fibres B1, B2, B4, B5 and sub-categories B6_a1 and B6_a2, category A1 graded-index multimode fibres and sub-category A4f, A4g and A4h fibr
42、es with the use of a Nd:YAG/fibre Raman laser source or multiple laser diodes operating at a number of wavelengths, both greater than and less than, the typical zero-dispersion wavelength. In this method, the time difference of optical pulse delay through a known length of fibre at several wavelengt
43、hs is measured. A reference set of measurements shall also be taken through a short reference fibre and data are subtracted from data taken from the fibre under test to obtain relative spectral group delay. The resultant spectral group delay data are then fitted to an equation defined for each fibre
44、 (sub) category. 3.3 Method C, differential phase shift This method describes a procedure for determining the chromatic dispersion of the categories of class B single-mode fibres B1, B2, B4, B5 and sub-categories B6_a1 and B6_a2, category A1 graded-index multimode fibres and sub-category A4f, A4g an
45、d A4h fibres. The dispersion coefficient at a particular wavelength is determined from the differential group delay between two closely spaced wavelengths. In this procedure, a modulated light source is coupled into the fibre under test, and the phase of the light exiting the fibre at a first wavele
46、ngth is compared with the phase of the light exiting at a second wavelength. Average chromatic dispersion over the interval between the two wavelengths is determined from differential phase shift, wavelength interval, and fibre length. The chromatic dispersion coefficient at a wavelength medial to t
47、he two test wavelengths is assumed to be equal to the average chromatic dispersion over the interval between the two BS EN 60793-1-42:2013 8 60793-1-42 IEC:2013 wavelengths. The resultant chromatic dispersion data are then fitted to an equation defined for each fibre (sub) category. 4 Reference test
48、 methods 4.1 Category A1 and sub-category A4f, A4g and A4h multimode fibres For category A1 and sub-category A4f, A4g and A4h multimode fibres, method B, spectral group delay in the time domain, is the reference test method (“RTM“), which shall be the one used to resolve disputes . 4.2 Class B singl
49、e-mode fibres For the categories of class B single-mode fibres B1, B2, B4, B5 and sub-categories B6_a1 and B6_a2, method A, phase shift, is the RTM. In the absence of method A, method C, differential phase shift, may also be used to resolve disputes. 5 Apparatus 5.1 General The following apparatus is common to all measurement methods. Annexes A, B and C include layout drawings and other equipment requirements that individually apply for each of the methods, A, B and C respectively. 5.2
