SIST EN IEC 61290-4-3:2018

Optical amplifiers - Test methods - Part 4-3: Power transient parameters - Single channel optical amplifiers in output power control (IEC 61290-4-3:2018)

IEC 61290-4-3:2018 applies to output power controlled optically amplified, elementary sub‑systems. It applies to optical fibre amplifiers (OFAs) using active fibres containing rare‑earth dopants, presently commercially available, as indicated in IEC 61291-1, as well as alternative optical amplifiers that can be used for single channel output power controlled operation, such as semiconductor optical amplifiers (SOAs). The object of this document is to provide the general background for optical amplifiers (OAs) power transients and their measurements and to indicate those IEC standard test methods for accurate and reliable measurements of the following transient parameters:
a) transient power response;
b) transient power overcompensation response;
c) steady-state power offset;
d) transient power response time.
The stimulus and responses behaviours under consideration include the following:
1. channel power increase (step transient);
2. channel power reduction (inverse step transient);
3. channel power increase/reduction (pulse transient);
4. channel power reduction/increase (inverse pulse transient);
5. channel power increase/reduction/increase (lightning bolt transient);
6. channel power reduction/increase/reduction (inverse lightning bolt transient).
These parameters have been included to provide a complete description of the transient behaviour of an output power transient controlled OA. The test definitions defined here are applicable if the amplifier is an OFA or an alternative OA. However, the description in Annex A concentrates on the physical performance of an OFA and provides a detailed description of the behaviour of an OFA; it does not give a similar description of other OA types. Annex B provides a detailed description background of the dynamic phenomenon in output power controlled amplifiers under transient conditions and Annex C details the impact of speed of transient inputs.This second edition cancels and replaces the first edition published in 2015. This edition constitutes a technical revision. This edition includes the following significant technical change with respect to the previous edition: alignment of the measure of amplified spontaneous emission (ASE) relative to signal power with the definition in IEC 61290-3-3.
Keywords: optical amplifiers (OAs) power transients
This International Standard is to be used in conjunction with IEC 61291-1:2012

Optische Verstärker - Prüfverfahren - Teil 4-3: Leistungs-Transientenkenngrößen von Ein-Kanal-LWL-Verstärkern mit Ausgangs-Leistungskontrolle (IEC 61290-4-3:2018)

Amplificateurs optiques - Méthodes d'essai - Partie 4-3: Paramètres de puissance transitoire - Contrôle de la puissance de sortie des amplificateurs optiques monocanaux (IEC 61290-4-3:2018)

L'IEC 61290-4-3:2018 s'applique aux sous-systèmes élémentaires à amplification optique et commandés par la puissance de sortie. Elle applique aux amplificateurs à fibres optiques utilisant des fibres actives dopées aux terres rares disponibles sur le marché, comme indiqué dans l'IEC 61291-1, mais aussi à des amplificateurs optiques alternatifs qui peuvent être utilisés pour un fonctionnement monocanal commandé par la puissance de sortie, tels que des amplificateurs optiques à semiconducteurs.
Le présent document a pour objet de fournir le contexte général pour les puissances transitoires des amplificateurs optiques et leurs mesures, ainsi que de décrire des méthodes d'essai normalisées de l'IEC pour effectuer des mesures précises et fiables des paramètres des transitoires suivants:
a) réponse de puissance transitoire;
b) réponse de surcompensation de puissance transitoire;
c) décalage de puissance en régime permanent;
d) temps de réponse de puissance transitoire.
Les comportements des stimuli et des réponses étudiés incluent les éléments suivants:
1. augmentation de la puissance d'un canal (transitoire en échelon);
2. diminution de la puissance d'un canal (transitoire en échelon inverse);
3. augmentation/diminution de la puissance d'un canal (transitoire en impulsion);
4. diminution/augmentation de la puissance d'un canal (transitoire en impulsion inverse);
5. augmentation/diminution/augmentation de la puissance d'un canal (transitoire en éclair);
6. diminution/augmentation/diminution de la puissance d'un canal (transitoire en éclair inverse).
Ces paramètres ont été inclus pour fournir une description complète du comportement des transitoires d'un amplificateur optique commandé par la puissance transitoire de sortie. Les essais définis ici sont applicables si l'amplificateur est un amplificateur à fibres optiques ou un amplificateur optique alternatif. Toutefois, l'Annexe A décrit les performances physiques d'un amplificateur à fibres optiques et fournit une description détaillée du comportement des amplificateurs à fibres optiques, mais ne donne pas de description similaire d'autres types d'amplificateurs optiques. L’Annexe B fournit des informations contextuelles de descriptions détaillées du phénomène dynamique se produisant dans les amplificateurs commandés par la puissance de sortie dans des conditions transitoires et l’Annexe C précise l’effet produit par la vitesse des entrées transitoires. Cette deuxième édition annule et remplace la première édition publiée en 2015. Cette édition constitue une révision technique  Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: alignement de la mesure d'une émission spontanée amplifiée sur la puissance d'un signal selon la définition de l'IEC 61290-3-3.
Mots clés: puissances transitoires des amplificateurs optiques
La présente Norme internationale doit être utilisée conjointement avec l'IEC 61291-1:2012.

Optični ojačevalniki - Preskusne metode - 4-3. del: Električni parametri ojačenja - Enokanalni optični ojačevalniki za izhodno krmiljenje moči (IEC 61290-4-3:2018)

Ta del standarda IEC 61290 se uporablja za optično ojačane osnovne podsisteme z izhodnim krmiljenjem moči. Uporablja se za ojačevalnike z optičnimi vlakni (OFA), ki uporabljajo aktivna vlakna s trenutno komercialno dostopnimi redkimi zemeljskimi dopanti, kot je navedeno v standardu IEC 61291-1, ter tudi za alternativne optične ojačevalnike, ki jih je mogoče uporabiti za enokanalno izhodno krmiljenje moči, kot so polprevodniški optični ojačevalniki (SOA).
Cilj tega dokumenta je zagotoviti splošno ozadje za ojačanje moči optičnih ojačevalnikov (OA) in njihove meritve ter določitev tistih standardnih preskusnih metod IEC, ki zagotavljajo natančne in zanesljive meritve naslednjih parametrov ojačanja:
a) odziv ojačane moči;
b) odziv prekomerne kompenzacije ojačane moči;
c) izravnava moči pri ustaljenih razmerah;
d) odzivni čas ojačane moči.
Obravnavana vedenja stimulusov in odzivov vključujejo naslednje:
1) povečanje moči kanala (koračno ojačanje);
2) zmanjšanje moči kanala (obratno koračno ojačanje);
3) povečanje/zmanjšanje moči kanala (pulzno ojačanje);
4) zmanjšanje/povečanje moči kanala (obratno pulzno ojačanje);
5) povečanje/zmanjšanje/povečanje moči kanala (bliskovito ojačanje);
6) zmanjšanje/povečanje/zmanjšanje moči kanala (obratno bliskovito ojačanje).
Ti parametri so bili vključeni z namenom zagotovitve popolnega opisa ojačevalnega vedenja optičnega ojačevalnika (OA) za izhodno krmiljenje moči. Tukaj opredeljene definicije preskusa veljajo, če je ojačevalnik tipa OFA ali OA. Vendar se opis v dodatku A osredotoča na fizično zmogljivost ojačevalnika z optičnimi vlakni (OFA) in zagotavlja podroben opis vedenja takšnega ojačevalnika; ne podaja podobnega opisa drugih vrst optičnih ojačevalnikov (OA). V Dodatku B je podrobno opisano ozadje dinamičnega pojava pri ojačevalnikih z izhodnim krmiljenjem moči pod ojačanimi pogoji in v Dodatku C je podrobno predstavljen vpliv hitrosti ojačanih vhodov.

General Information

• Status: Published
• Public Enquiry End Date: 28-Sep-2017
• Publication Date: 20-Aug-2018
• ICS: 33.180.30 - Optic amplifiers
• Technical Committee: MOC - Mobile Communications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 26-Jul-2018
• Due Date: 30-Sep-2018
• Completion Date: 21-Aug-2018
• Ref Project: EN IEC 61290-4-3:2018 - Optical amplifiers - Test methods - Part 4-3: Power transient parameters - Single channel optical amplifiers in output power control

Relations

• Replaces: SIST EN 61290-4-3:2016 - Optical amplifiers - Test methods - Part 4-3: Power transient parameters - Single channel optical amplifiers in output power control (IEC 61290-4-3:2015)
• Effective Date: 17-Jul-2018
• Revised: SIST EN 61290-4-3:2016 - Optical amplifiers - Test methods - Part 4-3: Power transient parameters - Single channel optical amplifiers in output power control (IEC 61290-4-3:2015)
• Effective Date: 06-Jun-2017

Overview

EN IEC 61290-4-3:2018 (IEC 61290-4-3:2018) - Optical amplifiers - Test methods - Part 4-3 - specifies test methods and measurement definitions for power transient parameters of single‑channel optical amplifiers operated in output power control. It applies to optical fibre amplifiers (OFAs) using rare‑earth doped fibres and to alternative amplifier types such as semiconductor optical amplifiers (SOAs). This second edition (2018) replaces the 2015 edition and aligns the measurement of amplified spontaneous emission (ASE) relative to signal power with IEC 61290-3-3.

Key topics

• Scope and applicability
  • Single‑channel output power controlled optical amplifiers (OAs): OFAs and alternative OAs (e.g., SOAs).
• Measured transient parameters
  • Transient power response
  • Transient power overcompensation response
  • Steady‑state power offset
  • Transient power response time
• Stimulus/response cases covered
  • Step increase (channel power increase)
  • Inverse step (channel power reduction)
  • Pulse and inverse pulse
  • “Lightning bolt” and inverse lightning bolt (increase/reduction/increase and reduction/increase/reduction)
• Test methodology
  • Test set‑up, required apparatus characteristics, test sample preparation, measurements, calculations and reporting of results.
  • Templates and figures provided for consistent test conditioning and result presentation.
• Informative annexes
  • Annex A: detailed overview of OFA physical transient behaviour.
  • Annex B: background on dynamic transient phenomena in output‑power controlled amplifiers.
  • Annex C: impact of input slew rate on transient gain response.

Applications

• Manufacturers: design verification and qualification of OFAs and SOAs for predictable transient performance under output power control.
• Test laboratories: standardized test procedures for repeatable measurements of amplifier transient metrics and ASE alignment.
• System integrators & network operators: assessment of amplifier behavior during channel add/drop, protection switching, or rapid power changes to ensure receiver tolerance and network stability.
• Product compliance & procurement: objective criteria for acceptance testing, interoperability checks and performance benchmarking.

Who should use this standard

• Optical amplifier designers, QA engineers, optical test engineers, telecom equipment vendors, and standards compliance teams working on fibre‑optic subsystems and single‑channel amplifier modules.

Related standards

• IEC 61291-1:2012 - Optical amplifiers - Generic specification (to be used in conjunction with IEC 61290-4-3).
• IEC 61290-3-3 - Measurement definition referenced for ASE alignment.

Keywords: optical amplifiers (OAs) power transients, power transient parameters, output power control, optical fibre amplifier (OFA), semiconductor optical amplifier (SOA), EN IEC 61290-4-3:2018, ASE measurement, test methods.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2018
1DGRPHãþD
SIST EN 61290-4-3:2016
2SWLþQLRMDþHYDOQLNL3UHVNXVQHPHWRGHGHO(OHNWULþQLSDUDPHWULRMDþHQMD
(QRNDQDOQLRSWLþQLRMDþHYDOQLNL]DL]KRGQRNUPLOMHQMHPRþL,(&
Optical amplifiers - Test methods - Part 4-3: Power transient parameters - Single channel
optical amplifiers in output power control (IEC 61290-4-3:2018)
Optische Verstärker - Prüfverfahren - Teil 4-3: Leistungs-Transientenkenngrößen von Ein
-Kanal-LWL-Verstärkern mit Ausgangs-Leistungskontrolle (IEC 61290-4-3:2018)
Amplificateurs optiques - Méthodes d'essai - Partie 4-3: Paramètres de puissance
transitoire - Contrôle de la puissance de sortie des amplificateurs optiques monocanaux
(IEC 61290-4-3:2018)
Ta slovenski standard je istoveten z: EN IEC 61290-4-3:2018
ICS:
33.180.30 2SWLþQLRMDþHYDOQLNL Optic amplifiers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61290-4-3

NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2018
ICS 33.180.30 Supersedes EN 61290-4-3:2015
English Version
Optical amplifiers - Test methods - Part 4-3: Power transient
parameters - Single channel optical amplifiers in output power
control
(IEC 61290-4-3:2018)
Amplificateurs optiques - Méthodes d'essai - Partie 4-3: Optische Verstärker - Prüfverfahren - Teil 4-3: Leistungs-
Paramètres de puissance transitoire - Amplificateurs Transientenkenngrößen von Ein-Kanal-LWL-Verstärkern
optiques monocanaux commandés par la puissance de mit Ausgangs-Leistungskontrolle
sortie (IEC 61290-4-3:2018)
(IEC 61290-4-3:2018)
This European Standard was approved by CENELEC on 2018-06-01. 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 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, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61290-4-3:2018 E

European foreword
The text of document 86C/1505/FDIS, future edition 2 of IEC 61290-4-3, prepared by subcommittee
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 IEC 61290-4-3:2018.

The following dates are fixed:
• latest date by which the document has to be (dop) 2019-03-01
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2021-06-01
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61290-4-3:2015.

This edition constitutes a technical revision, including the following technical change with respect to
the previous 2015 edition: alignment of the measurement of amplified spontaneous emission (ASE)
relative to signal power with definition given in EN 61290-3-3.

This European Standard is to be used in conjunction with EN 61291-1:2012.

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 61290-4-3:2018 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 61290-3-3 NOTE Harmonized as EN 61290-3-3.
IEC 61290-4-1 NOTE Harmonized as EN 61290-4-1.

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  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 61291-1 -  Optical amplifiers - Part 1: Generic EN IEC 61291-1 -
specification
IEC 61290-4-3 ®
Edition 2.0 2018-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical amplifiers – Test methods –

Part 4-3: Power transient parameters – Single channel optical amplifiers in

output power control
Amplificateurs optiques – Méthodes d'essai –

Partie 4-3: Paramètres de puissance transitoire – Amplificateurs optiques

monocanaux commandés par la puissance de sortie

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.30 ISBN 978-2-8322-5639-8

– 2 – IEC 61290-4-3:2018 © IEC 2018
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviated terms . 6
3.1 Terms and definitions . 6
3.2 Abbreviated terms . 7
4 Apparatus . 8
4.1 Test set-up . 8
4.2 Characteristics of test equipment . 8
5 Test sample . 9
6 Procedure . 9
6.1 Test preparation. 9
6.2 Test . 10
7 Calculations . 10
8 Test results . 11
8.1 Test setting conditions . 11
8.2 Test data . 12
Annex A (informative) Overview of power transient events in single channel EDFA . 13
A.1 Background. 13
A.2 Characteristic input power behaviour . 13
A.3 Parameters for characterizing transient behaviour . 16
Annex B (informative) Background on power transient phenomena in a single channel
EDFA . 17
B.1 Amplifier chains in optical networks . 17
B.2 Typical optical amplifier design . 17
B.3 Approaches to address detection errors . 19
Annex C (informative) Slew rate effect on transient gain response . 23
Bibliography . 24

Figure 1 – Power transient test set-up. 8
Figure 2 – OA output power transient response of a) input power increase and b)
decrease . 11
Figure A.1 – Example OA input power transient cases for a receiver application . 14
Figure A.2 – Input power measurement parameters . 15
Figure A.3 – OA output power transient response . 16
Figure B.1 – Transient response to input power drop . 21
Figure B.2 – Transient response to input power rise . 22

Table 1 – Template for transient control measurement test conditions . 10

IEC 61290-4-3:2018 © IEC 2018 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL AMPLIFIERS – TEST METHODS –

Part 4-3: Power transient parameters –
Single channel optical amplifiers in output power control

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
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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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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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
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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 61290-4-3 has been prepared by subcommittee 86C: Fibre optic
systems and active devices, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition published in 2015. This edition
constitutes a technical revision.
This edition includes the following significant technical change with respect to the previous
edition: alignment of the measure of amplified spontaneous emission (ASE) relative to signal
power with the definition in IEC 61290-3-3.

– 4 – IEC 61290-4-3:2018 © IEC 2018
The text of this International Standard is based on the following documents:
FDIS Report on voting
86C/1505/FDIS 86C/1512/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be used in conjunction with IEC 61291-1:2012.
A list of all parts of the IEC 61290 series, published under the general title Optical amplifiers –
Test methods, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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.
IEC 61290-4-3:2018 © IEC 2018 – 5 –
OPTICAL AMPLIFIERS – TEST METHODS –

Part 4-3: Power transient parameters –
Single channel optical amplifiers in output power control

1 Scope
This part of IEC 61290 applies to output power controlled optically amplified, elementary
sub-systems. It applies to optical fibre amplifiers (OFAs) using active fibres containing
rare-earth dopants, presently commercially available, as indicated in IEC 61291-1, as well as
alternative optical amplifiers that can be used for single channel output power controlled
operation, such as semiconductor optical amplifiers (SOAs).
The object of this document is to provide the general background for optical amplifiers (OAs)
power transients and their measurements and to indicate those IEC standard test methods for
accurate and reliable measurements of the following transient parameters:
a) transient power response;
b) transient power overcompensation response;
c) steady-state power offset;
d) transient power response time.
The stimulus and responses behaviours under consideration include the following:
1) channel power increase (step transient);
2) channel power reduction (inverse step transient);
3) channel power increase/reduction (pulse transient);
4) channel power reduction/increase (inverse pulse transient);
5) channel power increase/reduction/increase (lightning bolt transient);
6) channel power reduction/increase/reduction (inverse lightning bolt transient).
These parameters have been included to provide a complete description of the transient
behaviour of an output power transient controlled OA. The test definitions defined here are
applicable if the amplifier is an OFA or an alternative OA. However, the description in
Annex A concentrates on the physical performance of an OFA and provides a detailed
description of the behaviour of an OFA; it does not give a similar description of other OA
types. Annex B provides a detailed description background of the dynamic phenomenon in
output power controlled amplifiers under transient conditions and Annex C details the impact
of speed of transient inputs.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 61291-1, Optical amplifiers – Part 1: Generic specification

– 6 – IEC 61290-4-3:2018 © IEC 2018
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
input signal
optical signal that is input to the OA
3.1.2
input power excursion
relative input power difference before, during and after the input power stimulus event that
causes an OA transient power excursion
Note 1 to entry: Input power excursion is expressed in dB.
3.1.3
input power rise time
time it takes for the input optical signal to rise from 10 % to 90 % of the total difference
between the initial and final signal levels during an increasing power excursion event
Note 1 to entry: See Figure A.2 a).
3.1.4
input power fall time
time it takes for the input optical signal to fall from 90 % to 10 % of the total difference
between the initial and final signal levels during a decreasing power excursion event
Note 1 to entry: See Figure A.2 b).
3.1.5
slew rate
maximum rate of change of the input optical signal during a power excursion event
Note 1 to entry: See Annex C.
3.1.6
transient power response
maximum or minimum deviation (overshoot or undershoot) between the OA’s target power
and the observed power excursion induced by a change in an input channel power excursion
Note 1 to entry: Once the output power of an amplified channel deviates from its target power, the control
electronics in the OA should attempt to compensate for the power difference or transient power response, bringing
the OA output power back to its original target level.
Note 2 to entry: Transient power response is expressed in dB.
3.1.7
transient power response time
amount of time taken to restore the power of the OA to a stable power level close to the target
power level
Note 1 to entry: This parameter is measured from the time when the stimulus event created the power fluctuation
to the time at which the OA power response is stable and within specification.

IEC 61290-4-3:2018 © IEC 2018 – 7 –
3.1.8
transient power overcompensation response
maximum deviation between the amplifier’s target output power and the power resulting from
the control electronics’ instability
Note 1 to entry: Transient power overcompensation response occurs after a power excursion, when an amplifier’s
control electronics attempts to bring the power back to the amplifier’s target level. The control process is iterative,
and control electronics may initially overcompensate for the power excursion until subsequently reaching the
desired target power level.
Note 2 to entry: The transient power overcompensation response parameter is generally of lesser magnitude than
the transient power response and has the opposite sign.
Note 3 to entry: Transient power overcompensation response is expressed in dB.
3.1.9
steady state power offset
difference between the final and initial output power of the OA, prior to the power excursion
stimulus event
Note 1 to entry: Normally, the steady state power level following a power excursion differs from the OA power
before the input power stimulus event. The transient controller attempts to overcome this offset using feedback.
Note 2 to entry: Steady state power offset is expressed in dB.
3.2 Abbreviated terms
AFF ASE flattening filter
AGC automatic gain controller
APC automatic power control
ASE amplified spontaneous emission
ASEP amplified spontaneous emission power
BER bit error ratio
DFB distributed feedback (laser)
DWDM dense wavelength division multiplexing
EDF erbium-doped fibre
EDFA erbium-doped fibre amplifier
GFF gain flattening filter
NEM network equipment manufacturers
NSP network service providers
O/E optical-to-electrical
OA optical amplifier
OD optical damage
OFA optical fibre amplifier
OSA optical spectrum analyser
OSNR optical signal-to-noise ratio
PDs photodiodes
PID proportional integral-derivative
SOA semiconductor optical amplifier
Sig_ASE signal-to-ASE ratio
SigP signal power
SOP state of polarization
VOA variable optical attenuator
WDM wavelength division multiplexing

– 8 – IEC 61290-4-3:2018 © IEC 2018
4 Apparatus
4.1 Test set-up
Figure 1 shows a generic set-up to characterise the transient response properties of output
power controlled single channel OAs.
OA
Channel pass-
Optical
Polarization
under
Laser source VOA
band filter
modulator
scrambler
test
VOA
Function generator
O/E converter
Oscilloscope
IEC
Figure 1 – Power transient test set-up
4.2 Characteristics of test equipment
The test equipment listed below is needed, with the required characteristics:
a) Laser source for supplying the OA input signal with the following characteristics.
– ability to support the range of signal wavelengths for which the OA under test is to be
tested. This could be provided for example by a tuneable laser, or a bank of distributed
feedback (DFB) lasers;
– an achievable average output power such that at the input to the OA under test, the
power will be above the maximum specified input power of the OA, including loss of
any subsequent test equipment between the laser source and OA under test.
b) Polarization scrambler to randomize the incoming polarization state of the laser source, or
to control it to a defined state of polarization (SOP). The polarization scrambler is
optional.
c) Variable optical attenuator (VOA) with a dynamic range sufficient to support the required
range of surviving signal levels at which the OA under test is to be tested.
NOTE If the output power of the laser source can be varied over the required dynamic range, then a VOA is
not needed.
d) Optical modulator to modify the OA input signal to the defined power excursion with the
following characteristics;
– extinction ratio at rewrite without putting a number higher than the maximum drop level
for which the OA under test is to be tested;
– switching time fast enough to support the fastest slew rate for which the OA under test
is to be tested.
e) Channel pass-band filter: an optical filter designed to distinguish the signal wavelength
with the following characteristics. Note that the use of a channel pass-band filter is
optional:
– ability to support the range of signal wavelengths for which the OA under test is to be
tested. This could be provided for example by a tuneable filter, or a series of discrete
filters;
– 1-dB passband of at least ±20 GHz centred around the signal wavelength;

IEC 61290-4-3:2018 © IEC 2018 – 9 –
– more than 20 dB attenuation level below the minimum insertion loss across the entire
specified transmission band of the OA under test, except within a range of ±100 GHz
centred around the signal wavelength.
f) VOA before the optical-to-electrical (O/E) converter to ensure the maximum power is
within the linear response range.
g) Optical-to-electrical (O/E) convertor to detect the filtered output of the OA under test with
the following characteristics:
– a sufficiently wide optical and electrical bandwidth to support the fastest slew rate for
which the OA is to be tested;
– a linear response within a ±5 dB range of all signal levels for which the OA under test
is to be tested.
h) Oscilloscope to measure and capture the transient response of the optically filtered output
of the OA under test, with a sufficiently wide electrical bandwidth to support the fastest
slew rate for which the OA is to be tested.
i) Function generator to generate the input power transient waveforms to drive the optical
modulator, with electrical pulse width short enough and electrical slew rate high enough to
support the fastest slew rate for which the OA under test is to be tested.
5 Test sample
The OA shall operate under nominal operating conditions. If the OA is likely to cause laser
oscillations due to unwanted reflections, optical isolators should be used to isolate the OA
under test. This will minimize signal instability.
6 Procedure
6.1 Test preparation
In the set-up shown in Figure 1, the input optical signal power injected into the amplifier being
tested is generated from a suitable laser source. The optical power is passed through an
optional polarization scrambler to allow randomization or control of the signal polarization
state and is subsequently adjusted with a VOA to the desired optical input power levels. The
signal then passes through an optical modulator driven by a function generator that provides
the desired input power test waveform to stimulate the transient input power excursions. The
signal is then injected into the amplifier being tested. A channel pass-band filter (such as a
tuneable optical filter, fixed optical filter or similar component) may be used to select only the
relevant channel wavelength under test, followed by an O/E converter and an oscilloscope at
the output of the amplifier. The output channel selected by the optional channel pass-band
filter including its transient response is monitored with the O/E converter and oscilloscope.
Waveforms similar to those shown in Figure A.3 are captured via the oscilloscope for
subsequent computer processing.
Prior to measurement of the transient response, the input power waveform trace shall be
recorded. Use the set-up of Figure 1 without the OFA under test. The input optical connector
from the optical modulator is connected to the channel pass-band filter.
For this test, to stimulate a power excursion at the input of the OA under test, the source laser
power at the OA input is set at some typical power level. The function generator waveform is
chosen to increase or decrease the input power to the OA under test with power excursions
and slew rate relevant to the defined test condition. For example, for a typical number in the
case of an optical receiver, the input power to the OA could be increased by 7 dB in a
timeframe of 50 µs and then held at this power value to simulate a power increase transient
power response (step transient) condition as shown in Figure A.1 a). For alternative transient
control measurements, the signal generator waveform is controlled appropriately, and the
VOA is adjusted accordingly.
– 10 – IEC 61290-4-3:2018 © IEC 2018
6.2 Test
Several sequential transient control measurements can be performed according to the OA’s
specified operating conditions. Examples of power excursion scenarios are shown in Table 1.
These measurements are typically performed over a broad range of input power levels.
Table 1 – Template for tr
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