SIST EN IEC 61290-1-3:2021

Optical amplifiers - Test methods - Part 1-3: Power and gain parameters - Optical power meter method (IEC 61290-1-3:2021)

This part of IEC 61290 applies to all commercially available optical amplifiers (OA) and optically
amplified subsystems. It applies to OA using optically pumped fibres (OFA based on either rareearth
doped fibres or on the Raman effect), semiconductors (SOA), and waveguides (POWA).
NOTE 1 The applicability of the test methods described in this document to distributed Raman amplifiers is for
further study.
The object of this document is to establish uniform requirements for accurate and reliable
measurements, by means of the optical power meter test method, of the following OA
parameters, as defined in IEC 61291-1:
a) nominal output signal power;
b) gain;
c) polarization-dependent gain;
d) maximum output signal power;
e) maximum total output power.
NOTE 2 All numerical values followed by (‡) are suggested values for which the measurement is assured. Other
values can be acceptable upon verification.
This document applies to single-channel amplifiers. For multichannel amplifiers,
IEC 61290-10 (all parts) applies.

Prüfverfahren für Lichtwellenleiter-Verstärker - Teil 1-3: Optische Leistungs- und Verstärkerparameter - Verfahren mit optischem Leistungsmessgerät (IEC 61290-1-3:2021)

Amplificateurs optiques - Méthodes d'essai - Partie 1-3: Paramètres de puissance et de gain - Méthode par appareil de mesure de la puissance optique (IEC 61290-1-3:2021)

IEC 61290-1-3:2021 est disponible sous forme de IEC 61290-1-3:2021 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.

L'IEC 61290-1-3:2021 s’applique à tous les amplificateurs optiques (AO) et sous-systèmes à amplification optique, disponibles sur le marché. Elle s’applique aux AO utilisant des fibres pompées optiquement (AFO basé sur des fibres dopées aux terres rares ou sur l’effet Raman), des semiconducteurs (AOS), et des guides d’ondes (POWA).
NOTE 1 L’applicabilité des méthodes d’essai décrites dans le présent document à des amplificateurs Raman répartis est destinée à une étude ultérieure. L'objet du présent document est d'établir des exigences uniformes pour des mesurages précis et fiables, par le biais de la méthode d'essai par appareil de mesure de la puissance optique, des paramètres d’AO donnés ci-dessous, tels qu’ils sont définis dans l'IEC 61291-1:
- puissance nominale du signal de sortie;
- gain;
- gain en fonction de la polarisation;
- puissance maximale du signal de sortie;
- puissance totale de sortie maximale
NOTE 2 Toutes les valeurs numériques suivies de (‡) sont des valeurs suggérées, pour lesquelles le mesurage est assuré. D’autres valeurs peuvent être acceptables après vérification.
Le présent document s'applique aux amplificateurs à un seul canal. Pour les amplificateurs à canaux multiples, l’IEC 61290-10 (toutes les parties) s'applique. Cette quatrième édition annule et remplace la troisième édition parue en 2015. Cette édition constitue une révision technique. La présente édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- harmonisation avec l'IEC 61290-1-1;
- utilisation du terme "incertitude de mesure" au lieu de "précision de mesure".

Optični ojačevalniki - Preskusne metode - 1-3. del: Parametri moči in ojačenja - Metoda z merilnikom optične moči (IEC 61290-1-3:2021)

General Information

• Status: Published
• Publication Date: 04-May-2021
• ICS: 33.180.30 - Optic amplifiers
• Technical Committee: MOC - Mobile Communications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 28-Apr-2021
• Due Date: 03-Jul-2021
• Completion Date: 05-May-2021
• Ref Project: EN IEC 61290-1-3:2021 - Optical amplifiers - Test methods - Part 1-3: Power and gain parameters - Optical power meter method

Relations

• Revised: SIST EN 61290-1-3:2015 - Optical amplifiers - Test methods - Part 1-3: Optical power and gain parameters - Optical power meter method (IEC 61290-1-3:2015)
• Effective Date: 21-Jan-2020
• Replaces: SIST EN 61290-1-3:2015 - Optical amplifiers - Test methods - Part 1-3: Optical power and gain parameters - Optical power meter method (IEC 61290-1-3:2015)
• Effective Date: 20-Apr-2021
• Replaces: SIST EN 61290-1-3:2015 - Optical amplifiers - Test methods - Part 1-3: Optical power and gain parameters - Optical power meter method (IEC 61290-1-3:2015)
• Effective Date: 07-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 61290-1-3:2021
01-junij-2021
Nadomešča:
SIST EN 61290-1-3:2015
Optični ojačevalniki - Preskusne metode - 1-3. del: Parametri moči in ojačenja -
Metoda z merilnikom optične moči (IEC 61290-1-3:2021)
Optical amplifiers - Test methods - Part 1-3: Power and gain parameters - Optical power
meter method (IEC 61290-1-3:2021)
Prüfverfahren für Lichtwellenleiter-Verstärker - Teil 1-3: Optische Leistungs- und
Verstärkerparameter - Verfahren mit optischem Leistungsmessgerät (IEC 61290-1-
3:2021)
Amplificateurs optiques - Méthodes d'essai - Partie 1-3: Paramètres de puissance et de
gain - Méthode par appareil de mesure de la puissance optique (IEC 61290-1-3:2021)
Ta slovenski standard je istoveten z: EN IEC 61290-1-3:2021
ICS:
33.180.30 Optični ojačevalniki Optic amplifiers
SIST EN IEC 61290-1-3:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 61290-1-3:2021

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SIST EN IEC 61290-1-3:2021


EUROPEAN STANDARD EN IEC 61290-1-3

NORME EUROPÉENNE

EUROPÄISCHE NORM
April 2021
ICS 33.180.30 Supersedes EN 61290-1-3:2015 and all of its
amendments and corrigenda (if any)
English Version
Optical amplifiers - Test methods - Part 1-3: Power and gain
parameters - Optical power meter method
(IEC 61290-1-3:2021)
Amplificateurs optiques - Méthodes d'essai - Partie 1-3: Prüfverfahren für Lichtwellenleiter-Verstärker - Teil 1-3:
Paramètres de puissance et de gain - Méthode par appareil Leistungs- und Verstärkerparameter - Verfahren mit
de mesure de la puissance optique optischem Leistungsmessgerät
(IEC 61290-1-3:2021) (IEC 61290-1-3:2021)
This European Standard was approved by CENELEC on 2021-04-05. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, 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
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 61290-1-3:2021 E

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SIST EN IEC 61290-1-3:2021
EN IEC 61290-1-3:2021 (E)
European foreword
The text of document 86C/1671/CDV, future edition 4 of IEC 61290-1-3, 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 IEC 61290-1-3:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022-01-05
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024-04-05
document have to be withdrawn
This document supersedes EN 61290-1-3:2015 and all of its amendments and corrigenda (if any).
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 61290-1-3:2021 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 60793-1-1 NOTE Harmonized as EN 60793-1-1
IEC 60793-1-40 NOTE Harmonized as EN IEC 60793-1-40
IEC 60825-1 NOTE Harmonized as EN 60825-1
IEC 60825-2 NOTE Harmonized as EN 60825-2
IEC 61290-1 NOTE Harmonized as EN 61290-1
IEC 61290-1-1 NOTE Harmonized as EN IEC 61290-1-1
IEC 61290-10 (series) NOTE Harmonized as EN IEC 61290-10 (series)
2

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SIST EN IEC 61290-1-3:2021
EN IEC 61290-1-3:2021 (E)
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 60793-2-50 - Optical fibres - Part 2-50: Product EN IEC 60793-2-50 -
specifications - Sectional specification for
class B single-mode fibres
IEC 61291-1 - Optical amplifiers – Part 1: Generic EN IEC 61291-1 -
specification

3

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SIST EN IEC 61290-1-3:2021



IEC 61290-1-3

®


Edition 4.0 2021-03




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE











Optical amplifiers – Test methods –

Part 1-3: Power and gain parameters – Optical power meter method



Amplificateurs optiques – Méthodes d'essai –

Partie 1-3: Paramètres de puissance et de gain – Méthode par appareil de

mesure de la puissance optique















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 33.180.30 ISBN 978-2-8322-9475-8




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN IEC 61290-1-3:2021
– 2 – IEC 61290-1-3:2021 © IEC 2021
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviated terms . 5
3.1 Terms and definitions . 5
3.2 Abbreviated terms . 6
4 Apparatus . 7
5 Test sample . 9
6 Procedure . 9
7 Calculation . 12
8 Test results . 13
Annex A (informative)  Optimization of optical bandpass filter spectral width . 15
Bibliography . 16

Figure 1 – Typical arrangement of optical power meter test apparatus for measurement . 7

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SIST EN IEC 61290-1-3:2021
IEC 61290-1-3:2021 © IEC 2021 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

OPTICAL AMPLIFIERS – TEST METHODS –

Part 1-3: Power and gain parameters – Optical power meter method

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.
IEC 61290-1-3 has been prepared by subcommittee 86C: Fibre optic systems and active
devices, of IEC technical committee 86: Fibre optics. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2015. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) harmonization with IEC 61290-1-1;
b) use of the term "measurement uncertainty" instead of "measurement accuracy".

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SIST EN IEC 61290-1-3:2021
– 4 – IEC 61290-1-3:2021 © IEC 2021
The text of this International Standard is based on the following documents:
Draft Report on voting
86C/1671/CDV 86C/1698/RVC

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts in 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.

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SIST EN IEC 61290-1-3:2021
IEC 61290-1-3:2021 © IEC 2021 – 5 –
OPTICAL AMPLIFIERS – TEST METHODS –

Part 1-3: Power and gain parameters – Optical power meter method



1 Scope
This part of IEC 61290 applies to all commercially available optical amplifiers (OA) and optically
amplified subsystems. It applies to OA using optically pumped fibres (OFA based on either rare-
earth doped fibres or on the Raman effect), semiconductors (SOA), and waveguides (POWA).
NOTE 1 The applicability of the test methods described in this document to distributed Raman amplifiers is for
further study.
The object of this document is to establish uniform requirements for accurate and reliable
measurements, by means of the optical power meter test method, of the following OA
parameters, as defined in IEC 61291-1:
a) nominal output signal power;
b) gain;
c) polarization-dependent gain;
d) maximum output signal power;
e) maximum total output power.
NOTE 2 All numerical values followed by (‡) are suggested values for which the measurement is assured. Other
values can be acceptable upon verification.
This document applies to single-channel amplifiers. For multichannel amplifiers,
IEC 61290-10 (all parts) applies.
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 60793-2-50, Optical fibres – Part 2-50: Product specifications – Sectional specification for
class B single-mode fibres
IEC 61291-1, Optical amplifiers – Part 1: Generic specification
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61291-1 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

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SIST EN IEC 61290-1-3:2021
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3.2 Abbreviated terms
ASE amplified spontaneous emission
DBR distributed Bragg reflector (laser diode)
DFB distributed feedback (laser diode)
ECL external cavity laser (diode)
FWHM full width at half maximum
LED light emitting diode
OA optical amplifier
OFA optical fibre amplifier
OSA optical spectrum analyzer
PDL polarization dependent loss
POWA planar optical waveguide amplifier
SOA semiconductor optical amplifier

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SIST EN IEC 61290-1-3:2021
IEC 61290-1-3:2021 © IEC 2021 – 7 –
4 Apparatus
A diagram of the measurement set-up is given in Figure 1 a), Figure 1 b), Figure 1 c) and
Figure 1 d).

a) Measurement of input signal power

b) Measurement of optical bandpass filter loss and jumper loss

c) Measurement of output signal power and gain

d) Measurement of total output power
Key
J1, J2 optical connector
Figure 1 – Typical arrangement of optical power meter test apparatus for measurement

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SIST EN IEC 61290-1-3:2021
– 8 – IEC 61290-1-3:2021 © IEC 2021
The test equipment listed below, with the required characteristics, is needed.
a) Optical source: The optical source shall be either at fixed wavelength or wavelength-
tuneable.
– Fixed-wavelength optical source: This optical source shall generate a light with a
wavelength and optical power specified in the relevant product specification. Unless
otherwise specified, the optical source shall emit a continuous wave with FWHM of the
spectrum narrower than 1 nm (‡). A distributed feedback (DFB) laser, a distributed Bragg
reflector (DBR) laser, an external cavity laser (ECL) diode, a light emitting diode (LED)
with a narrow-band filter and a single line laser are applicable, for example.
The suppression ratio for the side modes for the DFB laser, the DBR laser or the ECL
shall be higher than 30 dB (‡). The output power fluctuation shall be less than 0,05 dB
(‡), which can be more easily attainable with an optical isolator at the output port of the
optical source. Spectral broadening at the foot of the lasing spectrum shall be minimal
for laser sources, and the ratio of the source power to total spontaneous emission power
of the laser shall be more than 30 dB.
– Wavelength-tuneable optical source: This optical source shall be able to generate a
wavelength-tuneable light within the range specified in the relevant product
specification. Its optical power shall be specified in the relevant product specification.
Unless otherwise specified, the optical source shall emit a continuous wave with the full
width at half maximum (FWHM) of the spectrum narrower than 1 nm (‡). An ECL or an
LED with a narrow bandpass optical filter is applicable, for example. The suppression
ratio of side modes for the ECL shall be higher than 30 dB (‡). The output power
fluctuation shall be less than 0,05 dB, which can be more easily attainable with an optical
isolator at the output port of the optical source. Spectral broadening at the foot of the
lasing spectrum shall be minimal for laser sources, and the ratio of the source power to
total spontaneous emission power of the laser shall be more than 30 dB.
b) Optical power meter: It shall have a measurement uncertainty of less than 0,2 dB,
irrespective of the state of polarization, within the operational wavelength bandwidth of the
OA. A maximum optical input power shall be large enough [e.g. +20 dBm (‡)]. Sensitivity
shall be high enough [e.g. −40 dBm (‡)]. A dynamic range exceeding the measured gain is
required (e.g. 40 dB).
c) Optical isolator: Optical isolators may be used to bracket the OA. The polarization
dependent loss (PDL) of the isolator shall be less than 0,2 dB (‡). Optical isolation shall be
more than 40 dB (‡). The reflectance from this device shall be smaller than –40 dB (‡) at
each port.
d) Variable optical attenuator: The attenuation range and stability shall be over 40 dB (‡) and
less than  0,2 dB (‡), respectively. The reflectance from this device shall be smaller
than −40 dB (‡) at each port.
e) Polarization controller: This device shall be able to provide as input signal light all possible
states of polarization (e.g. linear, elliptical and circular). For example, the polarization
controller may consist of a linear polarizer followed by an all-fibre-type polarization
controller, or by a linear polarizer followed by a quarter-wave plate rotatable by minimum of
90° and a half wave plate rotatable by minimum of 180°. The loss variation of the polarization
controller shall be less than 0,2 dB (‡). The reflectance from this device shall be smaller
than −40 dB (‡) at each port. The use of a polarization controller is considered optional,
except for the measurement of polarization dependent gain, but can be necessary to achieve
the desired accuracy for OA devices exhibiting significant polarization dependent gain.
f) Optical fibre jumpers: The optical fibre jumpers used shall be of the same fibre category
defined in IEC 60793-2-50 as the fibres used as input and output ports of the OA, so that
the mode field diameters of the optical fibre jumpers closely match those of the input and
output fibres of the OA. The reflectance from this device shall be smaller than −40 dB (‡) at
each port, and the length of the jumper shall be shorter than 2 m.
g) Optical connectors: The connection loss repeatability shall be less than 0,2 dB. The
reflectance from this device shall be smaller than −40 dB (‡).
h) Optical bandpass filter: The optical bandwidth (FWHM) of this device shall be less than 3 nm
(‡). It shall be either wavelength-tuneable or an appropriate set of fixed bandpass filters.

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IEC 61290-1-3:2021 © IEC 2021 – 9 –
During measurement, the difference between the centre wavelength of this bandwidth and
the optical source centre wavelength shall be no more than 1,5 nm (‡). The PDL of the
bandpass filter shall be less than 0,2 dB (‡). The reflectance from this device shall be
smaller than −40 dB (‡).
NOTE 1 Optimization of optical band pass filter spectral width is discussed in Annex A.
i) Optical coupler: The polarization dependence of the branching ratio of the coupler shall be
less than 0,1 dB (‡). Any unconnected port of the coupler shall be properly terminated, in
such a way as to decrease the reflectance below −40 dB (‡).
NOTE 2 The change of the state of polarization of the input light is typically negligible.
j) Wavelength meter: It shall have a wavelength measurement uncertainty of less than
0,1 nm (‡). If the optical source is so calibrated that the uncertainty of the wavelength is
less than 0,1 nm (‡), the wavelength meter is not necessary.
5 Test sample
The OA shall operate at nominal operating conditions. If the OA is likely to cause laser
oscillations due to unwanted reflections, use of optical isolators is recommended to bracket the
OA under test. This will reduce the signal instability and the measurement uncertainty.
Standard optical fibres type B-652.B or B-652.D as defined in IEC 60793-2-50 are
recommended. Even if fibre type other than B-652.B or B-652.D is used as input/output fibre,
the mode field diameter of the optical fibre jumpers closely matches those of the input and
output fibres of the OA [see Clause 4 f)].
For all parameter measurements except polarization-dependent gain, care shall be taken to
maintain the state of polarization of the input light during the measurement. Changes in the
polarization state of the input light can result in input optical power changes because of the
slight polarization dependency expected from all the optical components used, thus leading to
measurement uncertainty.
6 Procedure
a) Nominal output signal power: The nominal output signal power is given by the minimum
output signal optical power, for an input signal optical power specified in the relevant product
specification, and under nominal operating conditions, given in the relevant product
specification. To find this minimum value, input and output signal power levels shall be
continuously monitored for a given duration of time and in presence of changes in the state
of polarization and other instabilities, as specified in the relevant product specification. The
measurement procedures described below shall be followed, with reference to Figure 1.
In order to minimize the amplified spontaneous emission (ASE) power contribution to the
signal power output from the OA, several methods may be used. The optical bandpass filter
method is given below.
1) Set the optical source at the test wavelength specified in the relevant product
specification, measuring the input signal wavelength (e.g. with a wavelength meter).
2) Measure the branching ratio of the optical coupler through the signal power levels exiting
the two output ports with an optical power meter.
3) Measure the loss L of the optical bandpass filter and the optical fibre jumper between
bj
the OA and the optical power meter [see Figure 1 b)] by the insertion loss technique [see
method B (insertion loss) in IEC 60793-1-40].
4) Activate the OA under test and evaluate the ASE power level passed through the optical
filter, P , by measuring the optical output power from the OA, as shown in Figure 1 c),
ASE
without input signal.
NOTE 1 The small-signal regime is when the OA under test operates in the linear regime, whereas the
large-signal regime is when it operates in the saturated regime. The distinction between small-signal and

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large-signal regimes can be made by plotting G versus the input signal power with a constant pump drive.
The linear regime requires the time-averaged input signal power to be in the range in which the gain is quite
independent of the input signal power (see IEC 61290-1). An input signal power ranging from −30 dBm to
−40 dBm is generally well within this range. In the saturated regime, the signal power is large enough to
well suppress the ASE, so that the measurement of the ASE power is sometimes omitted.
NOTE 2 For consideration of measurement uncertainty, refer to the last paragraph of Annex A, which
concerns the optimization of the optical band pass filter spectral width.
5) Set the optical source and the variable optical attenuator in such a way as to provide, at
the input port of the OA, the input optical signal power (P ) specified in the relevant
in
product specification. Record the optical power (P ) measured with an optical power
o
meter at the other (second) output port of the optical coupler, as shown in Figure 1 a).
Applying signal light with short rise time into the OA operating without signal light can
cause the generation of an optical surge which can damage the optical components. The
input signal shall have sufficiently small power to prevent the optical surge, when it is
launched to the OA initially. The input power shall be gradually increased to the specified
level.
6) Keep the optical signal power at the OA input constant (P ) during the following
in
measurements, by monitoring the second output port of the coupler and, if necessary,
setting the variable optical attenuator in such a way that the optical power (P ) exiting
o
the second output port of the optical coupler remains constant.
7) Connect the fibre jumpers to the input and output port of the OA under test, as shown in
Figure 1 c) and evaluate the optical output power (P ) with input signal.
out
If the polarization controller is used, the following procedure shall be adapted.
8) Set the polarization controller at a given state of polarization as specified in the relevant
product specification; activate the OA, and monitor, by means of the optical power meter,
the optical signal power at the output of the OA, for the specified period of time, recording
the minimum value.
9) Change the state of polarization of the input signal by means of the polarization
controller, trying to measure maximum and minimum output optical signal powers with
the optical power meter, and repeat procedure 8).
10) Repeat procedure step 9) for the different states of polarization indicated in the relevant
product specification and, finally, take the absolute minimum and maximum output
optical signal powers recorded in the various conditions: P and P .
out-min out-max
Optical connectors J1 and J2 shall not be removed during the measurement to avoid
measurement uncertainty due to reconnection.
The measurement uncertainty shall be reduced by eliminating the effect of the ASE
simultaneously detected with the signal. This is better attainable by placing an optical
bandpass filter having the narrower passband at the output of the OA under test, as it has
been discussed in Clause 6 a). For large optical signal power levels, the optical bandpass
filter is often not necessary to achieve an accurate measurement. The use of the optical
bandpass filter is especially important when the input signal to the OA is small. This is
because the AS
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