SIST EN 61280-2-2:2013
(Main)Fibre optic communication subsystem test procedures - Part 2-2: Digital systems - Optical eye pattern, waveform and extinction ratio measurement (IEC 61280-2-2:2012)
Fibre optic communication subsystem test procedures - Part 2-2: Digital systems - Optical eye pattern, waveform and extinction ratio measurement (IEC 61280-2-2:2012)
The purpose of this part of IEC 61280 is to describe a test procedure to verify compliance with a predetermined waveform mask and to measure the eye pattern and waveform parameters such as rise time, fall time, modulation amplitude and extinction ratio.
Prüfverfahren für Lichtwellenleiter-Kommunikationsuntersysteme - Teil 2-2: Digitale Systeme - Messung des optischen Augendiagramms, der Wellenform und des Extinktionsverhältnisses (IEC 61280-2-2:2012)
Procédures d'essai des sous-systèmes de télécommunications à fibres optiques - Partie 2-2: Systèmes numériques - Mesure du diagramme de l'oeil optique, de la forme d'onde et du taux d'extinction (CEI 61280-2-2:2012)
IEC 61280-2-2: 2012 décrit une procédure d’essai pour vérifier la conformité à un masque de forme d’onde prédéterminé et mesurer le diagramme de l’œil et les paramètres de la forme d’onde tels que le temps de montée, le temps de descente, l'amplitude de modulation et le taux d’extinction. Cette quatrième édition annule et remplace la troisième édition parue en 2008 et constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: définitions supplémentaires; clarification des procédures d'essai.
La présente version bilingue (2020-09) correspond à la version anglaise monolingue publiée en 2012-10.
Postopki preskušanja optičnega komunikacijskega podsistema - 2-2. del: Digitalni sistemi - Merjenje po vzorcu optičnega očesa, valovne oblike in hitrosti ugašanja (IEC 61280-2-2:2012)
Namen tega dela standarda IEC 61280 je opisati postopek preskušanja za preverjanje skladnosti s predhodno določeno masko valovne oblike ter izmeriti vzorec očesa in parametre valovne oblike, kot so čas dviga, čas padca, amplituda modulacije in hitrost ugašanja.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 61280-2-2:2013
01-februar-2013
1DGRPHãþD
SIST EN 61280-2-2:2008
3RVWRSNLSUHVNXãDQMDRSWLþQHJDNRPXQLNDFLMVNHJDSRGVLVWHPDGHO 'LJLWDOQL
VLVWHPL0HUMHQMHSRY]RUFXRSWLþQHJDRþHVDYDORYQHREOLNHLQKLWURVWLXJDãDQMD
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Fibre optic communication subsystem test procedures - Part 2-2: Digital systems -
Optical eye pattern, waveform and extinction ratio measurement (IEC 61280-2-2:2012)
Prüfverfahren für Lichtwellenleiter-Kommunikationsuntersysteme - Teil 2-2: Digitale
Systeme - Messung des optischen Augendiagramms, der Wellenform und des
Extinktionsverhältnisses (IEC 61280-2-2:2012)
Procédures d'essai des sous-systèmes de télécommunications à fibres optiques - Partie
2-2: Systèmes numériques - Mesure du diagramme de l'oeil optique, de la forme d'onde
et du taux d'extinction (CEI 61280-2-2:2012)
Ta slovenski standard je istoveten z: EN 61280-2-2:2012
ICS:
33.180.01 6LVWHPL]RSWLþQLPLYODNQLQD Fibre optic systems in
VSORãQR general
SIST EN 61280-2-2:2013 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 61280-2-2:2013
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SIST EN 61280-2-2:2013
EUROPEAN STANDARD
EN 61280-2-2
NORME EUROPÉENNE
December 2012
EUROPÄISCHE NORM
ICS 33.180.01 Supersedes EN 61280-2-2:2008
English version
Fibre optic communication subsystem test procedures -
Part 2-2: Digital systems -
Optical eye pattern, waveform and extinction ratio measurement
(IEC 61280-2-2:2012)
Procédures d'essai des sous-systèmes Prüfverfahren für Lichtwellenleiter-
de télécommunications à fibres optiques - Kommunikationsuntersysteme -
Partie 2-2: Systèmes numériques - Teil 2-2: Digitale Systeme -
Mesure du diagramme de l'oeil optique, Messung des optischen
de la forme d'onde et du taux d'extinction Augendiagramms, der Wellenform
(CEI 61280-2-2:2012) und des Extinktionsverhältnisses
(IEC 61280-2-2:2012)
This European Standard was approved by CENELEC on 2012-11-29. 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.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Management Centre: Avenue Marnix 17, B - 1000 Brussels
© 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61280-2-2:2012 E
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SIST EN 61280-2-2:2013
EN 61280-2-2:2012 - 2 -
Foreword
The text of document 86C/1043/CDV, future edition 4 of IEC 61280-2-2, prepared by SC 86C "Fibre
optic systems and active devices" of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC
parallel vote and approved by CENELEC as EN 61280-2-2:2012.
The following dates are fixed:
(dop) 2013-08-29
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2015-11-29
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61280-2-2:2008.
EN 61280-2-2:2012 includes the following significant technical changes with respect to
EN 61280-2-2:2008:
- additional definitions;
- clarification of test procedures.
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 61280-2-2:2012 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60825-1 NOTE Harmonised as EN 60825-1.
IEC 61281-1 NOTE Harmonised as EN 61281-1.
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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.
Publication Year Title EN/HD Year
IEC 61280-2-3 - Fibre optic communication subsystem EN 61280-2-3 -
test procedures -
Part 2-3: Digital systems - Jitter and wander
measurements
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SIST EN 61280-2-2:2013
IEC 61280-2-2
®
Edition 4.0 2012-10
INTERNATIONAL
STANDARD
colour
inside
Fibre optic communication subsystem test procedures –
Part 2-2: Digital systems – Optical eye pattern, waveform and extinction ratio
measurement
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
U
ICS 33.180.01 ISBN 978-2-83220-420-7
Warning! Make sure that you obtained this publication from an authorized distributor.
® Registered trademark of the International Electrotechnical Commission
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CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Apparatus . 7
4.1 General . 7
4.2 Reference receiver definition . 8
4.3 Time-domain optical detection system . 8
4.3.1 Overview . 8
4.3.2 Optical-to-electrical (O/E) converter . 9
4.3.3 Linear-phase low-pass filter . 9
4.3.4 Oscilloscope . 10
4.4 Overall system response . 11
4.5 Oscilloscope synchronization system. 11
4.5.1 General . 11
4.5.2 Triggering with a clean clock . 12
4.5.3 Triggering using a recovered clock . 12
4.5.4 Triggering directly on data . 13
4.6 Pattern generator . 14
4.7 Optical power meter . 14
4.8 Optical attenuator . 14
4.9 Test cord . 14
5 Signal under test . 14
6 Instrument set-up and device under test set-up . 14
7 Measurement procedures . 15
7.1 Overview . 15
7.2 Extinction ratio measurement . 15
7.2.1 Configure the test equipment . 15
7.2.2 Measurement procedure . 15
7.2.3 Extinction ratio calculation . 16
7.3 Eye amplitude . 17
7.4 Optical modulation amplitude (OMA) measurement using the square wave
method . 17
7.4.1 General . 17
7.4.2 Oscilloscope triggering . 17
7.4.3 Amplitude histogram, step 1 . 17
7.4.4 Amplitude histogram, step 2 . 18
7.4.5 Calculate OMA . 18
7.5 Contrast ratio (for RZ signals) . 18
7.6 Jitter measurements . 18
7.7 Eye width . 19
7.8 Duty cycle distortion (DCD) . 19
7.9 Crossing percentage . 20
7.10 Eye height . 21
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7.11 Q-factor/signal-to-noise ratio (SNR). 21
7.12 Rise time . 21
7.13 Fall time . 22
8 Eye-diagram analysis using a mask . 23
8.1 Eye mask testing using the ‘no hits’ technique . 23
8.2 Eye mask testing using the ‘hit-ratio’ technique . 24
9 Test result . 26
9.1 Required information . 26
9.2 Available information . 26
9.3 Specification information . 26
Bibliography . 27
Figure 1 – Optical eye pattern, waveform and extinction ratio measurement
configuration . 8
Figure 2 – Oscilloscope bandwidths commonly used in eye pattern measurements . 10
Figure 3 – PLL jitter transfer function and resulting observed jitter transfer function . 13
Figure 4 – Histograms centred in the central 20 % of the eye used to determine the
mean logic one and 0 levels, b and b . 16
1 0
Figure 5 – OMA measurement using the square wave method . 18
Figure 6 – Construction of the duty cycle distortion measurement . 20
Figure 7 – Construction of the crossing percentage measurement . 21
Figure 8 – Construction of the risetime measurement with no reference receiver
filtering . 22
Figure 9 – Illustrations of several RZ eye-diagram parameters . 23
Figure 10 – Basic eye mask and coordinate system . 24
Figure 11 – Mask margins at different sample population sizes . 26
Table 1 – Frequency response characteristics . 11
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC COMMUNICATION SUBSYSTEM
TEST PROCEDURES –
Part 2-2: Digital systems – Optical eye pattern,
waveform and extinction ratio measurement
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,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 61280-2-2 has been prepared by subcommittee 86C: Fibre optic
systems and active devices, of IEC technical committee 86: Fibre optics.
This fourth edition cancels and replaces the third edition published in 2008 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) additional definitions;
b) clarification of test procedures.
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61280-2-2 © IEC:2012(E) – 5 –
The text of this standard is based on the following documents:
CDV Report on voting
86C/1043/CDV 86C/1074/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.
A list of all parts in the IEC 61280 series, published under the general title Fibre optic
communication subsystem test procedures, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability 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.
A bilingual version of this publication may be issued at a later date.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
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FIBRE OPTIC COMMUNICATION SUBSYSTEM
TEST PROCEDURES –
Part 2-2: Digital systems – Optical eye pattern,
waveform and extinction ratio measurement
1 Scope
The purpose of this part of IEC 61280 is to describe a test procedure to verify compliance with
a predetermined waveform mask and to measure the eye pattern and waveform parameters
such as rise time, fall time, modulation amplitude and extinction ratio.
2 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 61280-2-3, Fibre optic communication subsystem test procedures – Part 2-3: Digital
systems – Jitter and wander measurements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
amplitude histogram
graphical means to display the power or voltage population distribution of a waveform
3.2
contrast ratio
ratio of the nominal peak amplitude to the nominal minimum amplitude of two adjacent logical
‘1’s when using return-to-zero transmission
3.3
duty cycle distortion
DCD
measure of the balance of the time width of a logical 1 bit to the width of a logical 0 bit,
indicated by the time between the eye diagram nominal rising edge at the average or 50 %
level and the eye diagram nominal falling edge at the average or 50 % level
3.4
extinction ratio
ratio of the nominal 1 level to the nominal 0 level of the eye diagram
3.5
eye diagram
type of waveform display that exhibits the overall performance of a digital signal by
superimposing all the acquired samples on a common time axis one unit interval in width
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3.6
eye height
difference between the 1 level, measured three standard deviation below the nominal 1 level
of the eye diagram, and 0 level, measured three standard deviations above the nominal 0
level of the eye diagram
3.7
eye mask
constellation of polygon shapes that define regions where the eye diagram may not exist,
thereby effectively defining the allowable shape of the transmitter waveform
3.8
eye width
time difference between the spread of the two crossing points of an eye diagram, each
measured three standard deviations toward the centre of the eye from their nominal positions
3.9
jitter
deviation of the logical transitions of a digital signal from their ideal positions in time
manifested in the eye diagram as the time width or spread of the crossing point
3.10
observed jitter transfer function
OJTF
ratio of the displayed or measured jitter relative to actual jitter, versus jitter frequency, when a
test system is synchronized with a clock derived from the signal being measured
3.11
reference receiver
description of the frequency and phase response of a test system, typically a fourth-order
Bessel-Thomson low-pass, used to analyze transmitter waveforms with the intent of achieving
consistent results whenever the test system complies with this expected response
3.12
signal-to-noise ratio
SNR
similar to Q-factor, the ratio of the difference of the nominal 1 and 0 level of the eye diagram
to the sum of the standard deviation of both the 1 level and the 0 level of the eye diagram
3.13
unit interval
for the NRZ signal, the unit interval is one bit period or the inverse of the signalling rate
4 Apparatus
4.1 General
The primary components of the measurement system are a photodetector, a low-pass filter,
an oscilloscope, and an optical power meter, as shown in Figure 1. Many transmitter
characteristics are derived from analysis of the transmitter time-domain waveform.
Transmitter waveform characteristics can vary depending on the frequency response and
bandwidth of the test system. To achieve consistent results, the concept of a reference
receiver is used. The reference receiver definition defines the combined frequency and phase
response of the optical-to-electrical converter, any filtering, and the oscilloscope. The
reference receiver frequency response is typically a low pass filter design and is discussed in
detail in 4.2. At high signalling rates, reference receiver frequency response can be difficult to
achieve when configured using individual components. It is common to integrate the reference
receiver within the oscilloscope system to achieve reference receiver specifications. Use of a
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low-pass filter which alone achieves reference receiver specifications often will not result in a
test system that achieves the required frequency response.
4.2 Reference receiver definition
A reference receiver typically follows a fourth-order low-pass Bessel response. A well-defined
low-pass frequency response will yield consistent results across all test systems that conform
to the specification. A low-pass response reduces test system noise and approaches the
bandwidth of the actual receiver that the transmitter will be paired with in an actual
communications system. As signal transients such as overshoot and ringing, which can lead
to eye mask failures, are usually suppressed by the reduced bandwidth of the system
receiver, it is appropriate to use a similar bandwidth in a transmitter test system. The Bessel
phase response yields near constant group delay in the passband, which in turn results in
minimal phase distortion of the time domain optical waveform. The bandwidth of the frequency
response typically is set to 0,75 (75 %) of the signalling rate. For example, the reference
receiver for a 10,0 GBd signal would have a –3 dB bandwidth of 7,5 GHz. For non-return to
zero (NRZ) signals, this response has the smallest bandwidth that does not result in vertical
or horizontal eye closure (inter-symbol interference). When the entire test system achieves
the fourth-order Bessel low-pass response with a bandwidth of 75 % of the baud rate, this is
referred to as a Bessel-Thomson reference receiver. Return-to-zero (RZ) signals require a
larger bandwidth reference receiver, but which has not been specified in any standards
committees.
IEC 1897/12
Figure 1 – Optical eye pattern, waveform
and extinction ratio measurement configuration
4.3 Time-domain optical detection system
4.3.1 Overview
The time-domain optical detection system displays the power of the optical waveform as a
function of time. The optical detection system is comprised primarily of a linear optical-to-
electrical (O/E) converter, a linear-phase low-pass filter and an electrical oscilloscope. The
output current of the linear photodetector must be directly proportional to the input optical
power. When the three elements are combined within an instrument, it becomes an optical
oscilloscope and can be calibrated to display optical power rather than voltage, as a function
of time. More complete descriptions of the equipment are listed in 4.3.2 to 4.3.4.
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4.3.2 Optical-to-electrical (O/E) converter
The O/E converter is typically a high-speed photodiode. The O/E converter is equipped with
an appropriate optical connector to allow connection to the optical interface point, either
directly or via an optical test cord. When low power signals are to be measured, the
photodetector may be followed by electrical amplification. The frequency response of the
amplification must be considered as it may impact the overall frequency response of the test
system.
Precise specifications are precluded by the large variety of possible implementations, but
general guidelines are as follows:
a) acceptable input wavelength range, adequate to cover the intended application;
b) input optical reflectance, low enough to avoid excessive back-reflection into the
transmitter being measured;
c) responsivity and low noise, adequate to produce an accurately measureable display on
the oscilloscope. The photodetector responsivity influences the magnitude of the
displayed signal. The photodetector and oscilloscope electronics generate noise. The
noise of the test system must be small compared to the observed signal. If the noise is
significant relative to the detected optical waveform, some measurements such as eye-
mask margin can be degraded. When the photodetector is integrated within the test
system oscilloscope, noise performance is specified directly as an RMS optical power
level (e.g. 5 mW). The responsivity of the photodetector is used to calibrate the vertical
scale of the instrument. Further discussion on the impact of noise is found in 6.1;
d) lower cut-off (–3 dB) frequency, 0 Hz;
e) DC coupling is necessary for two reasons. First, extinction ratio measurements cannot
otherwise be performed. Second, if AC-coupling is used, low-frequency spectral
components of the measured signal (below the lower cut-off frequency of the O/E
convert
...
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