SIST EN 60793-1-48:2008
(Main)Optical fibres -- Part 1-48: Measurement methods and test procedures - Polarization mode dispersion
Optical fibres -- Part 1-48: Measurement methods and test procedures - Polarization mode dispersion
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 optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes.
Lichtwellenleiter -- Teil 1-48: Messmethoden und Prüfverfahren - Polarisationsmodendispersion
Fibres optiques -- Partie 1-48: Méthodes de mesure et procédures d'essai - Dispersion du mode de polarisation
S'appliques aux trois méthodes de mesure de la dispersion de mode de polarisation (Polarization Mode Dispersion, PMD). Elle établit des exigences uniformes pour mesurer la PMD d'une fibre optique unimodale, de façon à aider dans l'examen des fibres et des câbles à des fins commerciales. Dans cette édition, la référence à la CEI 61289-2 a entraîné le retrait des Annexes E, F, G et H ainsi que la création d'une nouvelle Annexe E.
Optična vlakna - 1-48. del: Metode merjenja in preskusni postopki - disperzija z načinom polarizacije (IEC 60793-1-48:2007)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 60793-1-48:2008
01-februar-2008
1DGRPHãþD
SIST EN 60793-1-48:2004
2SWLþQDYODNQDGHO 0HWRGHPHUMHQMDLQSUHVNXVQLSRVWRSNLGLVSHU]LMD]
QDþLQRPSRODUL]DFLMH ,(&
Optical fibres - Part 1-48: Measurement methods and test procedures - Polarization
mode dispersion (IEC 60793-1-48:2007)
Lichtwellenleiter - Teil 1-48: Messmethoden und Prüfverfahren -
Polarisationsmodendispersion (IEC 60793-1-48:2007)
Fibres optiques - Partie 1-48: Méthodes de mesure et procédures d'essai - Dispersion du
mode de polarisation (IEC 60793-1-48:2007)
Ta slovenski standard je istoveten z: EN 60793-1-48:2007
ICS:
33.180.10 2SWLþQD YODNQDLQNDEOL Fibres and cables
SIST EN 60793-1-48:2008 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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EUROPEAN STANDARD
EN 60793-1-48
NORME EUROPÉENNE
November 2007
EUROPÄISCHE NORM
ICS 33.180.10 Supersedes EN 60793-1-48:2003
English version
Optical fibres -
Part 1-48: Measurement methods and test procedures -
Polarization mode dispersion
(IEC 60793-1-48:2007)
Fibres optiques - Lichtwellenleiter -
Partie 1-48: Méthodes de mesure Teil 1-48: Messmethoden
et procédures d'essai -
und Prüfverfahren -
Dispersion du mode de polarisation Polarisationsmodendispersion
(CEI 60793-1-48:2007) (IEC 60793-1-48:2007)
This European Standard was approved by CENELEC 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 standards 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 notified
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,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2007 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
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EN 60793-1-48:2007 – 2 –
Foreword
The text of document 86A/1038/CDV, future edition 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, reference 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 of 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 approved by CENELEC as a European
Standard without any modification.
__________
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– 3 – EN 60793-1-48:2007
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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 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.
Publication Year Title EN/HD Year
1) 2)
IEC 60793-1-1 – Optical fibres - EN 60793-1-1 2003
Part 1-1: Measurement methods and test
procedures - General and guidance
1) 2)
IEC 60793-1-44 – Optical fibres - EN 60793-1-44 2002
Part 1-44: Measurement methods and test
procedures - Cut-off wavelength
1) 2)
IEC 60793-2-50 – Optical fibres - EN 60793-2-50 2004
Part 2-50: Product specifications - + corr. July 2004
Sectional specification for class B
single-mode fibres
1) 2)
IEC 60794-3 – Optical fibres cables - EN 60794-3 2002
Part 3: Sectional specification - Outdoor
cables
1) 2)
IEC 61280-4-4 – Fibre optic communication subsystem test EN 61280-4-4 2006
procedures -
Part 4-4: Cable plants and links - Polarization
mode dispersion measurement for installed
links
1)
IEC/TR 61282-3 – Fibre optic communication system design – –
guides -
Part 3: Calculation of link polarization mode
dispersion
1)
IEC/TR 61282-9 – Fibre optic communication system design – –
guides -
Part 9: Guidance on polarization mode
dispersion measurements and theory
1) 2)
IEC 61290-11-1 – Optical amplifier test methods - EN 61290-11-1 2003
Part 11-1: Polarization mode dispersion -
Jones matrix eigenanalysis method (JME)
1) 2)
IEC 61290-11-2 – Optical amplifiers - Test methods - EN 61290-11-2 2005
Part 11-2: Polarization mode dispersion
parameter - Poincaré sphere analysis method
1)
Undated reference.
2)
Valid edition at date of issue.
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EN 60793-1-48:2007 – 4 –
Publication Year Title EN/HD Year
1)
IEC/TR 61292-5 – Optical amplifiers - – –
Part 5: Polarization mode dispersion
parameter - General information
1) 2)
IEC 61300-3-32 – Fibre optic interconnecting devices and EN 61300-3-32 2006
passive components - Basic test and
measurement procedures -
Part 3-32: Examinations and measurements -
Polarisation mode dispersion measurement
for passive optical components
1)
ITU-T – Definitions and test methods for statistical – –
Recommendation and non-linear related attributes of
G.650.2 single-mode fibre and cable
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INTERNATIONAL IEC
STANDARD
CEI
60793-1-48
NORME
Second edition
INTERNATIONALE
Deuxième édition
2007-06
Optical fibres –
Part 1-48:
Measurement methods and test procedures –
Polarization mode dispersion
Fibres optiques –
Partie 1-48:
Méthodes de mesure et procédures d’essai –
Dispersion du mode de polarisation
PRICE CODE
X
CODE PRIX
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
Pour prix, voir catalogue en vigueur
---------------------- Page: 6 ----------------------
– 2 – 60793-1-48 © IEC:2007
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope.7
2 Normative references .7
3 Terms and definitions .8
4 General .8
4.1 Methods for measuring PMD .8
4.2 Reference test method .10
4.3 Applicability.10
5 Apparatus.11
5.1 Light source and polarizers .11
5.2 Input optics .11
5.3 Input positioner .12
5.4 Cladding mode stripper .12
5.5 High-order mode filter.12
5.6 Output positioner.12
5.7 Output optics.12
5.8 Detector .12
5.9 Computer .12
6 Sampling and specimens.12
6.1 General .12
6.2 Specimen length.13
6.3 Deployment .13
7 Procedure .14
8 Calculation or interpretation of results .14
9 Documentation .14
9.1 Information required for each measurement .14
9.2 Information to be available .14
10 Specification information .15
Annex A (normative) Fixed analyser measurement method .16
Annex B (normative) Stokes evaluation method .27
Annex C (normative) Interferometry method.32
Annex D (informative) Determination of RMS width from a fringe envelope .42
Annex E (informative) Glossary of symbols .46
Bibliography.48
Figure A.1 – Block diagrams for Method A .16
Figure A.2 – Typical results from Method A.19
Figure A.3 – PMD by Fourier analysis .22
Figure A.4 – Cross-correlation and autocorrelation functions .26
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60793-1-48 © IEC:2007 – 3 –
Figure B.1 – Block diagram for Method B .27
Figure B.2 – Typical random-mode-coupling results from Method B .29
Figure B.3 – Typical histogram of DGD values .29
Figure C.1 – Schematic diagram for Method C (generic implementation).32
Figure C.2 – Other schematic diagrams for Method C .34
Figure C.3a – Random mode-coupling using a TINTY-based measurement system
with one I/O SOP .37
Figure C.3b – Negligible mode-coupling using a TINTY-based measurement system
with one I/O SOP .37
Figure C.3 – Fringe envelopes for negligible and random polarization mode-coupling .37
Figure C.4a – Random mode-coupling using a GINTY-based measurement system
with I/O-SOP scrambling.38
Figure C.4b – Negligible mode-coupling using a GINTY-based measurement system
with I/O-SOP scrambling.38
Figure C.4c – Mixed mode-coupling using a GINTY-based measurement system with
I/O-SOP scrambling .39
Figure C.4 – Fringe envelopes for negligible and random polarization mode-coupling
(Ginty procedure).39
Figure D.1 – Parameters for interferogram analysis .42
Table A.1 – Cosine transform calculations .25
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– 4 – 60793-1-48 © IEC:2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRES –
Part 1-48: Measurement methods and test procedures –
Polarization mode dispersion
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60793-1-48 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition published in 2003. It constitutes a
technical revision. In this edition, reference to IEC 61282-9 has resulted in the removal of
Annexes E, F, G and H as well as the creation of a new Annex E.
The text of this standard is based on the following documents:
CDV Report on voting
86A/1038/CDV 86A/1078/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
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60793-1-48 © IEC:2007 – 5 –
This standard is to be read in conjunction with IEC 60793-1-1.
A list of all parts of the IEC 60793 series, published under the general title Optical fibres, can
be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
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– 6 – 60793-1-48 © IEC:2007
INTRODUCTION
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 velocities and corresponding arrival times δτ of
different polarization components of the signal. For a sufficiently narrow band source, the
effect can be related to a differential group delay (DGD), Δτ, between pairs of orthogonally
polarized principal states of polarization (PSP) at a given wavelength. For broadband
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 birefringence 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, <Δτ>, or the mean DGD
over wavelength. In principle, the expected value <Δτ> does not undergo large changes for a
given fibre from day to day or from source to source, unlike the parameters δτ or Δτ. In
addition, <Δτ> 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 the specific sense of the expected value <Δτ>. The DGD Δτ or pulse
broadening δτ can be averaged over wavelength, yielding <Δτ> , or time, yielding <Δτ> , or
λ t
temperature, yielding <Δτ> . For most purposes, it is not necessary to distinguish between
T
these various options for obtaining <Δτ>.
The coupling length l is the length of fibre or cable at which appreciable coupling between
c
,
the two polarization states begins to occur. If the fibre length L satisfies the condition L << l
c
mode coupling is negligible and <Δτ> scales with fibre length. The corresponding PMD
coefficient is
"short-length" PMD coefficient = <Δτ>/L.
Fibres in practical systems are nearly always in the L >> l , regime and mode coupling is
c
random. If mode coupling is also found to be random, <Δτ> scales with the square root of
fibre length, and
"long-length" PMD coefficient = <Δτ>/ L
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60793-1-48 © IEC:2007 – 7 –
OPTICAL 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 optical 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 edition
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 fibres – 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 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 61290-11-1, 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 – Poincaré sphere analysis method
IEC/TR 61292-5, Optical amplifiers – Part 5: Polarization 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.650.2, Definitions and test methods for statistical and non-linear
related attributes of single-mode fibre and cable
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– 8 – 60793-1-48 © IEC:2007
3 Terms and definitions
For the purposes of this document, the terms 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 listed 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 eigenanalysis (JME)
• Poincaré 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), Δτ, which usually
varies randomly with wavelength, and is reported as 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 follow a Maxwell
random distribution.
PMD = Δτ (1)
AVG
1/ 2
2
PMD = Δτ (2)
RMS
1/ 2
8
⎛ ⎞ 1/ 2
Δτ =⎜ ⎟ Δτ (3)
3π
⎝ ⎠
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
distribution 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 begin to resemble the square root of a
non-central Chi-square distribution with three degrees of freedom. For these cases, the PMD value will
RMS
generally be larger relative to the PMD that is indicated in Equation (3). Time domain methods such as Method
AVG
C and Method A, cosine Fourier transform, which are based on PMD , can use Equation (3) to convert to
RMS
PMD . If mode coupling is reduced, the resultant reported PMD value from these methods may exceed those
AVG
that can be reported by the frequency domain measurements that report PMD , such as Method B.
AVG
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60793-1-48 © IEC:2007 – 9 –
The 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
1/2
PMD coefficient is reported in units of ps/km . For some fibres with negligible mode
coupling, such as polarization maintaining fibre, the PMD value is divided by the length and
the PMD coefficient is reported in units of ps/km.
All methods are suitable for laboratory measurements of factory lengths of optical fibre and
optical fibre cable. For all methods, changes in the deployment of the specimen can alter the
results. For installed lengths of optical fibre cable that may be moving or vibrating, either
Method C or Method B (in an implementation capable of millisecond measurement time
scales) is appropriate.
All methods require light sources that are controlled at one or more states of polarization
(SOPs). All methods require injecting light across a broad spectral region (i.e. 50 nm to
200 nm wide) to obtain a PMD value that is characteristic of the region (i.e. 1 300 nm or
1 550 nm). The methods differ in:
a) the wavelength characteristics of the source;
b) the physical characteristics that are actually measured;
c) the analysis methods.
Method A measures PMD by measuring a response to a change of narrowband light across a
wavelength range. At the source, the light is linearly polarized at one or more SOPs. For each
SOP, the change in output power that is filtered through a fixed polarization analyser, relative
to the power detected without the analyser, is measured as a function of wavelength. The
resulting measured function can be analysed in one of three ways.
– By counting the number of peaks and valleys (EC) of the curve and application of a
1)
formula that has been shown [1] to agree with the average of DGD values, when the
DGDs are distributed as Maxwellian. This analysis is considered as a frequency domain
approach.
– By taking the FT of the measured function. This FT is equivalent to the pulse spreading
obtained by the broadband transmission of Method C. Appropriate characterisation of the
width of the FT function agrees with the average of DGD values, when the DGDs are
distributed as Maxwellian.
– By taking the cosine Fourier transform of the difference of the normalized spectra from two
orthogonal analyzer settings and calculating the RMS of the squared envelope. The
PMD value is reported. This is equivalent to simulating the fringe pattern of the cross-
RMS
correlation function that would result from interferometric measurements.
Method B measures PMD by measuring a response to a change of narrowband light across a
wavelength range. At the source, the light is linearly polarized at on
...
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