1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58T
2、he European Standard EN 60793-1-48:2007 has the status of a British StandardICS 33.180.10Optical fibres Part 1-48: Measurement methods and test procedures Polarization mode dispersionBRITISH STANDARDBS EN 60793-1-48:2007BS EN 60793-1-48:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/0
3、4/2008 03:12, Uncontrolled Copy, (c) BSIThis British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 January 2008 BSI 2008ISBN 978 0 580 55009 6Amendments issued since publicationAmd. No. Date CommentsThis publication does not purport to include all th
4、e necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard is the UK implementation of EN 60793-1-48:2007. It is identical to IEC 60793-1-48:2007. It s
5、upersedes BS EN 60793-1-48:2003 which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/1, Optical fibres and cables.A list of organizations represented on this committee can be obtained on request to its secretary.
6、EUROPEAN STANDARD EN 60793-1-48 NORME EUROPENNE EUROPISCHE NORM November 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 20
7、07 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60793-1-48:2007 E ICS 33.180.10 Supersedes EN 60793-1-48:2003English version Optical fibres - Part 1-48: Measurement methods and test procedures - Polarization mode dispersion (IE
8、C 60793-1-48:2007) Fibres optiques - Partie 1-48: Mthodes de mesure et procdures dessai - Dispersion du mode de polarisation (CEI 60793-1-48:2007) Lichtwellenleiter -Teil 1-48: Messmethoden und Prfverfahren - Polarisationsmodendispersion (IEC 60793-1-48:2007) This European Standard was approved by C
9、ENELEC on 2007-09-01. 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 stan
10、dards may be obtained on application to the Central Secretariat 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 not
11、ified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuan
12、ia, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSIForeword The text of document 86A/1038/CDV, future edit
13、ion 2 of IEC 60793-1-48, prepared by SC 86A, Fibres and cables, of IEC TC 86, Fibre optics, was submitted to the IEC-CENELEC parallel Unique Acceptance Procedure and was approved by CENELEC as EN 60793-1-48 on 2007-09-01. This European Standard supersedes EN 60793-1-48:2003. In EN 60793-1-48:2007, r
14、eference to IEC/TR 61282-9 has resulted in the removal of Annexes E, F, G and H as well as the creation of a new Annex E. This standard is to be used in conjunction with EN 60793-1-1. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication o
15、f an identical national standard or by endorsement (dop) 2008-06-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-09-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60793-1-48:2007 was approv
16、ed by CENELEC as a European Standard without any modification. _ EN 60793-1-48:2007 2 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSICONTENTS INTRODUCTION.5 1 Scope.6 2 Normative references .6 3 Terms and definitions .7 4 General 7 4.1 Methods for
17、measuring PMD .7 4.2 Reference test method 9 4.3 Applicability.9 5 Apparatus.10 5.1 Light source and polarizers .10 5.2 Input optics .10 5.3 Input positioner .11 5.4 Cladding mode stripper .11 5.5 High-order mode filter11 5.6 Output positioner.11 5.7 Output optics.11 5.8 Detector 11 5.9 Computer 11
18、6 Sampling and specimens11 6.1 General .11 6.2 Specimen length12 6.3 Deployment .12 7 Procedure 13 8 Calculation or interpretation of results 13 9 Documentation .13 9.1 Information required for each measurement 13 9.2 Information to be available 13 10 Specification information 14 Annex A (normative)
19、 Fixed analyser measurement method 15 Annex B (normative) Stokes evaluation method .26 Annex C (normative) Interferometry method.31 Annex D (informative) Determination of RMS width from a fringe envelope 41 Annex E (informative) Glossary of symbols 45 Bibliography47 Figure A.1 Block diagrams for Met
20、hod A 15 Figure A.2 Typical results from Method A.18 Figure A.3 PMD by Fourier analysis.21 Figure A.4 Cross-correlation and autocorrelation functions 25 EN 60793-1-48:2007 3 Annex ZA (normative) Normative references to international publications with their corresponding European publications 48 Lice
21、nsed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSIFigure B.1 Block diagram for Method B26 Figure B.2 Typical random-mode-coupling results from Method B 28 Figure B.3 Typical histogram of DGD values 28 Figure C.1 Schematic diagram for Method C (generic imp
22、lementation).31 Figure C.2 Other schematic diagrams for Method C .32 Figure C.3a Random mode-coupling using a TINTY-based measurement system with one I/O SOP 36 Figure C.3b Negligible mode-coupling using a TINTY-based measurement system with one I/O SOP 36 Figure C.3 Fringe envelopes for negligible
23、and random polarization mode-coupling.36 Figure C.4a Random mode-coupling using a GINTY-based measurement system with I/O-SOP scrambling.37 Figure C.4b Negligible mode-coupling using a GINTY-based measurement system with I/O-SOP scrambling.37 Figure C.4c Mixed mode-coupling using a GINTY-based measu
24、rement system with I/O-SOP scrambling 38 Figure C.4 Fringe envelopes for negligible and random polarization mode-coupling (Ginty procedure)38 Figure D.1 Parameters for interferogram analysis 41 Table A.1 Cosine transform calculations 24 EN 60793-1-48:2007 4 Licensed Copy: Wang Bin, ISO/EXCHANGE CHIN
25、A STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSIINTRODUCTION Polarization mode dispersion (PMD) causes an optical pulse to spread in the time domain. This dispersion could impair the performance of a telecommunications system. The effect can be related to differential phase and group veloci
26、ties and corresponding arrival times of different polarization components of the signal. For a sufficiently narrow band source, the effect can be related to a differential group delay (DGD), , between pairs of orthogonally polarized principal states of polarization (PSP) at a given wavelength. For b
27、roadband transmission, the delays bifurcate and result in an output pulse that is spread out in the time domain. In this case, the spreading can be related to the average of DGD values. In long fibre spans, DGD is random in both time and wavelength since it depends on the details of the birefringenc
28、e along the entire fibre length. It is also sensitive to time-dependent temperature and mechanical perturbations on the fibre. For this reason, a useful way to characterize PMD in long fibres is in terms of the expected value, , or the mean DGD over wavelength. In principle, the expected value does
29、not undergo large changes for a given fibre from day to day or from source to source, unlike the parameters or . In addition, is a useful predictor of lightwave system performance. The term “PMD“ is used both in the general sense of two polarization modes having different group velocities, and in th
30、e specific sense of the expected value . The DGD or pulse broadening can be averaged over wavelength, yielding , or time, yielding t, or temperature, yielding T. For most purposes, it is not necessary to distinguish between these various options for obtaining . The coupling length lcis the length of
31、 fibre or cable at which appreciable coupling between the two polarization states begins to occur. If the fibre length L satisfies the condition L scales with fibre length. The corresponding PMD coefficient is “short-length“ PMD coefficient = /L. Fibres in practical systems are nearly always in the
32、L lc, regime and mode coupling is random. If mode coupling is also found to be random, scales with the square root of fibre length, and “long-length“ PMD coefficient = / L EN 60793-1-48:2007 5 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSIOPTICAL
33、FIBRES Part 1-48: Measurement methods and test procedures Polarization mode dispersion 1 Scope This part of IEC 60793 applies to three methods of measuring polarization mode dispersion (PMD), which are described in Clause 4. It establishes uniform requirements for measuring the PMD of single-mode op
34、tical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest ed
35、ition of the referenced document (including any amendments) applies. IEC 60793-1-1, Optical fibres Part 1-1: Measurement methods and test procedures General and guidance IEC 60793-1-44, Optical fibres Part 1-44: Measurement methods and test procedures Cut-off wavelength IEC 60793-2-50, Optical fibre
36、s Part 2-50: Product specifications Sectional specification for class B single-mode fibres IEC 60794-3, Optical fibre cables Part 3: Sectional specification Outdoor cables IEC 61280-4-4, Fibre optic communication subsystem test procedures Part 4-4: Cable plants and links Polarization mode dispersion
37、 measurement for installed links IEC/TR 61282-3, Fibre optic communication system design guides Part 3: Calculation of link polarization mode dispersion IEC/TR 61282-9, Fibre optic communication system design guides Part 9: Guidance on polarization mode dispersion measurements and theory IEC 61290-1
38、1-1, Optical amplifier test methods Part 11-1: Polarization mode dispersion Jones matrix eigenanalysis method (JME) IEC 61290-11-2, Optical amplifiers Test methods Part 11-2: Polarisation mode dispersion parameter Poincar sphere analysis method IEC/TR 61292-5, Optical amplifiers Part 5: Polarization
39、 mode dispersion parameter General information IEC 61300-3-32, Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 3-32: Examinations and measurements Polarization mode dispersion measurement for passive optical components ITU-T Recommendation G.650.
40、2, Definitions and test methods for statistical and non-linear related attributes of single-mode fibre and cable EN 60793-1-48:2007 6 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSI3 Terms and definitions For the purposes of this document, the term
41、s and definitions contained in ITU-T Recommendation G.650.2 apply. NOTE Further explanation of their use in this document is provided in IEC 61282-9. 4 General 4.1 Methods for measuring PMD Three methods are described for measuring PMD (see Annexes A, B and C for more details). The methods are liste
42、d below in the order of their introduction. For some methods, multiple approaches of analyzing the measured results are also provided. Method A Fixed analyser (FA) Extrema counting (EC) Fourier transform (FT) Cosine Fourier transform (CFT) Method B Stokes parameter evaluation (SPE) Jones matrix eige
43、nanalysis (JME) Poincar sphere analysis (PSA) State of polarization (SOP) Method C Interferometry (INTY) Traditional analysis (TINTY) General analysis (GINTY) The PMD value is defined in terms of the differential group delay (DGD), , which usually varies randomly with wavelength, and is reported as
44、one or another statistical metric. Equation (1) is a linear average value and is used for the specification of optical fibre cable. Equation (2) is the root mean square value which is reported by some methods. Equation (3) can be used to convert one value to the other if the DGDs are assumed to foll
45、ow a Maxwell random distribution. =AVGPMD (1) 212RMS/=PMD (22/12/138 = (3) NOTE Equation (3) applies only when the distribution of DGDs is Maxwellian, for instance when the fibre is randomly mode coupled. The generalized use of Equation (3) can be verified by statistical analysis. A Maxwell distribu
46、tion may not be the case if there are point sources of elevated birefringence (relative to the rest of the fibre), such as a tight bend, or other phenomena that reduce the mode coupling, such as a continual reduced bend radius with fibre in tension. In these cases, the distribution of the DGDs will
47、begin to resemble the square root of a non-central Chi-square distribution with three degrees of freedom. For these cases, the PMDRMSvalue will generally be larger relative to the PMDAVGthat is indicated in Equation (3). Time domain methods such as Method C and Method A, cosine Fourier transform, wh
48、ich are based on PMDRMS, can use Equation (3) to convert to PMDAVG. If mode coupling is reduced, the resultant reported PMD value from these methods may exceed those that can be reported by the frequency domain measurements that report PMDAVG, such as Method B. EN 60793-1-48:2007 7 Licensed Copy: Wa
49、ng Bin, ISO/EXCHANGE CHINA STANDARDS, 29/04/2008 03:12, Uncontrolled Copy, (c) BSIThe PMD coefficient is the PMD value normalized to the fibre length. For normal transmission fibre, for which random mode coupling occurs and for which the DGDs are distributed as Maxwell random variables, the PMD value is divided by the square root of the length and the PMD coefficient is reported in units of ps/km1/2
