SIST EN 61290-10-1:2009

Optical amplifier test methods - Part 10-1: Multichannel parameters - Pulse method using an optical switch and optical spectrum analyzer (IEC 61290-10-1:2009)

This part of IEC 61290 applies to optical amplifiers (OAs) using active fibres and waveguides, containing rare-earth dopants, currently commercially available. The object of this standard is to establish uniform requirements for accurate and reliable measurements of the signal-spontaneous noise figure as defined in IEC 61291-1. The test method independently detects amplified signal power and amplified spontaneous
emission (ASE) power by launching optical pulses into the OA under test and synchronously detecting "on" and "off" levels of the output pulses by using an optical sampling switch and an optical spectrum analyzer (OSA). Such measurement is possible because.

Prüfverfahren für Lichtwellenleiter-Verstärker - Teil 10-1: Mehrkanalparameter - Pulsmethode bei Verwendung eines optischen Schalters und optischen Spektralanalysators (IEC 61290-10-1:2009)

Amplificateurs optiques - Méthodes d'essai - Partie 10-1: Paramètres à canaux multiples - Méthode d’impulsion utilisant un interrupteur optique et un analyseur de spectre optique (CEI 61290-10-1:2009)

La CEI 61290-10-1:2009 s'applique aux amplificateurs optiques (AO) utilisant des fibres actives et des guides d'ondes, dopées aux terres rares, actuellement disponibles sur le marché. L'objet de la présente norme est d'établir des exigences uniformes en vue de mesures précises et fiables du facteur de bruit spontané-signal défini dans la CEI 61291-1. La méthode d'essai détecte indépendamment la puissance du signal amplifiée et la puissance d'émission spontanée amplifiée (ESA) en lançant des impulsions optiques dans l'AO en essai et en détectant en synchronisme les niveaux '1' et '0' des impulsions de sortie à l'aide d'un interrupteur d'échantillonnage optique et un analyseur de spectre optique (ASO). Cette deuxième édition annule et remplace la première édition parue en 2003. C'est une révision technique avec des références mises à jour, et des mises en garde concernant la bonne utilisation des procédures.   Cette publication doit être lue conjointement avec la CEI 61291-1:2006.

Optični ojačevalniki - Preskusne metode - 10-1. del: Parametri z več kanali - Metoda s pulzom pri uporabi optičnega stikala in optičnega spektralnega analizatorja (IEC 61290-10-1:2009)

General Information

• Status: Published
• Publication Date: 16-Jul-2009
• ICS: 33.180.30 - Optic amplifiers
• Technical Committee: iTEL - Communication cables
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 02-Jun-2009
• Due Date: 07-Aug-2009
• Completion Date: 17-Jul-2009
• Ref Project: EN 61290-10-1:2009 - Optical amplifiers - Test methods - Part 10-1: Multichannel parameters - Pulse method using an optical switch and optical spectrum analyzer

Relations

• Replaces: SIST EN 61290-10-1:2004 - Optical amplifiers - Test methods -- Part 10-1: Multichannel parameters - Pulse method using an optical switch and optical spectrum analyzer
• Effective Date: 01-Sep-2009
• Replaces: SIST EN 61290-10-1:2004 - Optical amplifiers - Test methods -- Part 10-1: Multichannel parameters - Pulse method using an optical switch and optical spectrum analyzer
• Effective Date: 29-Jan-2023
• Replaces: SIST EN 61290-10-1:2004 - Optical amplifiers - Test methods -- Part 10-1: Multichannel parameters - Pulse method using an optical switch and optical spectrum analyzer
• Effective Date: 13-May-2010

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 61290-10-1:2009
01-september-2009
1DGRPHãþD
SIST EN 61290-10-1:2004
2SWLþQLRMDþHYDOQLNL3UHVNXVQHPHWRGHGHO3DUDPHWUL]YHþNDQDOL
0HWRGDVSXO]RPSULXSRUDELRSWLþQHJDVWLNDODLQRSWLþQHJDVSHNWUDOQHJD
DQDOL]DWRUMD,(&
Optical amplifier test methods - Part 10-1: Multichannel parameters - Pulse method using
an optical switch and optical spectrum analyzer (IEC 61290-10-1:2009)
Prüfverfahren für Lichtwellenleiter-Verstärker - Teil 10-1: Mehrkanalparameter -
Pulsmethode bei Verwendung eines optischen Schalters und optischen
Spektralanalysators (IEC 61290-10-1:2009)
Amplificateurs optiques - Méthodes d'essai - Partie 10-1: Paramètres à canaux multiples
- Méthode d’impulsion utilisant un interrupteur optique et un analyseur de spectre optique
(CEI 61290-10-1:2009)
Ta slovenski standard je istoveten z: EN 61290-10-1:2009
ICS:
33.180.30 2SWLþQLRMDþHYDOQLNL Optic amplifiers
SIST EN 61290-10-1:2009 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61290-10-1:2009

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SIST EN 61290-10-1:2009

EUROPEAN STANDARD
EN 61290-10-1

NORME EUROPÉENNE
May 2009
EUROPÄISCHE NORM

ICS 33.180.30 Supersedes EN 61290-10-1:2003


English version


Optical amplifiers -
Test methods -
Part 10-1: Multichannel parameters -
Pulse method using an optical switch
and optical spectrum analyzer
(IEC 61290-10-1:2009)


Amplificateurs optiques -  Prüfverfahren
Méthodes d'essai - für Lichtwellenleiter-Verstärker -
Partie 10-1: Paramètres Teil 10-1: Mehrkanalparameter -
à canaux multiples - Pulsmethode bei Verwendung
Méthode d’impulsion utilisant eines optischen Schalters
un interrupteur optique und optischen Spektralanalysators
et un analyseur de spectre optique (IEC 61290-10-1:2009)
(CEI 61290-10-1:2009)



This European Standard was approved by CENELEC on 2009-04-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: Avenue Marnix 17, B - 1000 Brussels


© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61290-10-1:2009 E

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SIST EN 61290-10-1:2009
EN 61290-10-1:2009 – 2 –
Foreword
The text of document 86C/778/CDV, future edition 2 of IEC 61290-10-1, 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 was approved by CENELEC as EN 61290-10-1 on 2009-04-01.
This European Standard supersedes EN 61290-10-1:2003.
It contains updated references and cautions on proper use of the procedure.
This European Standard is to be read in conjunction with EN 61291-1.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2010-01-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2012-04-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61290-10-1:2009 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 NOTE  Harmonized in EN 60793-1 series (partially modified).
IEC 60825-1 NOTE  Harmonized as EN 60825-1:2007 (not modified).
IEC 60825-2 NOTE  Harmonized as EN 60825-2:2004 (not modified).
IEC 60874-1 NOTE  Harmonized as EN 60874-1:2007 (not modified).
IEC 61290-1-1 NOTE  Harmonized as EN 61290-1-1:2006 (not modified).
IEC 61290-3 NOTE  Harmonized as EN 61290-3:2008 (not modified).
__________

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SIST EN 61290-10-1:2009
– 3 – EN 61290-10-1:2009

Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

1) 2)
IEC 61291-1 - Optical amplifiers - EN 61291-1 2006
Part 1: Generic specification




1)
Undated reference.
2)
Valid edition at date of issue.

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SIST EN 61290-10-1:2009

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SIST EN 61290-10-1:2009
IEC 61290-10-1
®
Edition 2.0 2009-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Optical amplifiers – Test methods –
Part 10-1: Multichannel parameters – Pulse method using an optical switch and
optical spectrum analyzer

Amplificateurs optiques – Méthodes d'essai
Partie 10-1: Paramètres à canaux multiples – Méthode d’impulsion utilisant un
interrupteur optique et un analyseur de spectre optique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
T
CODE PRIX
ICS 33.180.30 ISBN 2-8318-1032-3
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN 61290-10-1:2009
– 2 – 61290-10-1 © IEC:2009
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope and object.7
2 Normative references .7
3 Abbreviated terms .7
4 Apparatus.8
5 Test sample.10
6 Procedure .10
6.1 Calibration.11
6.1.1 Calibration of OSA power measurement .11
6.1.2 Calibration of the pulse duty ratio .11
6.1.3 Calibration of the sampling module.12
6.1.4 Calibration of dynamic isolation .13
6.2 OA measurement .15
6.2.1 Timing adjustment for ASE and amplified signal power measurement.15
6.2.2 ASE measurement.16
6.2.3 Amplified signal power measurement.16
7 Calculation .17
7.1 General .17
7.2 Noise factor calculation .18
7.3 ASE power .18
7.4 Gain calculation .19
7.5 Average output signal power .19
7.6 Noise figure calculation .19
8 Test results .19
Annex A (informative) Output waveforms for various EDFAs at 25 kHz and 500 kHz
pulse rates.20
Annex B (informative) Measurement accuracy versus pulse rate.22
Annex C (informative) Pulse repetition frequency measurements.23
Bibliography.24

Figure 1 – Typical arrangement of the optical pulse test method .8
Figure 2 – Two arrangements of the optical pulse source.9
Figure 3 – Static isolation of an optical switch.9
Figure 4 – Definitions of rise time and fall time, t and t of optical pulses .10
r f
Figure 5 – Measurement flow chart .11
Figure 6 – Arrangement for the sampling switch calibration.12
Figure 7 – Arrangement for timing adjustment.13
Figure 8 – Timing adjustment of the sampling switch .14
Figure 9 – Timing chart for dynamic isolation calibration .15
Figure 10 – Arrangement for OA measurement .16
Figure 11 – Timing chart for ASE measurement .17
Figure 12 – Timing chart for amplified signal power measurement .17

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SIST EN 61290-10-1:2009
61290-10-1 © IEC:2009 – 3 –
Figure A.1 – EDFA output waveforms for various EDFAs .21
Figure B.1 – NF measurement accuracy versus pulse rate.22
Figure C.1 – Set-up to evaluate gain recovery error versus modulation rate.23
Figure C.2 – Gain recovery error versus modulation frequency with pump current as a
parameter .23

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SIST EN 61290-10-1:2009
– 4 – 61290-10-1 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

OPTICAL AMPLIFIERS –
TEST METHODS –

Part 10-1: Multichannel parameters –
Pulse method using an optical switch
and optical spectrum analyzer


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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment
declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses
arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights
International Standard IEC 61290-10-1 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 2003. It is a technical
revision with updated references and cautions on proper use of the procedure.
This International Standard is to be read in conjunction with IEC 61291-1.
The text of this standard is based on the following documents:
CDV Report on voting
86C/778/CDV 86C/809/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.

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SIST EN 61290-10-1:2009
61290-10-1 © IEC:2009 – 5 –
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 61290 series, published under the general title Optical amplifiers –
1)
Test methods can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
___________
1)
The first editions of some of these parts were published under the general title Optical fibre amplifiers – Basic
specification or Optical amplifier test methods.

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SIST EN 61290-10-1:2009
– 6 – 61290-10-1 © IEC:2009
INTRODUCTION
This International Standard is devoted to the subject of optical fibre amplifiers. The technology
of optical fibre amplifiers is still rapidly evolving, hence amendments and new editions to this
standard can be expected.

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SIST EN 61290-10-1:2009
61290-10-1 © IEC:2009 – 7 –
OPTICAL AMPLIFIERS –
TEST METHODS –

Part 10-1: Multichannel parameters –
Pulse method using an optical switch
and optical spectrum analyzer



1 Scope and object
This part of IEC 61290 applies to optical amplifiers (OAs) using active fibres and waveguides,
containing rare-earth dopants, currently commercially available.
The object of this standard is to establish uniform requirements for accurate and reliable
measurements of the signal-spontaneous noise figure as defined in IEC 61291-1.
The test method independently detects amplified signal power and amplified spontaneous
emission (ASE) power by launching optical pulses into the OA under test and synchronously
detecting "on" and "off" levels of the output pulses by using an optical sampling switch and an
optical spectrum analyzer (OSA).
Such measurement is possible because the gain response of the rare-earth doped OA is
relatively slow, particularly in Er-doped OAs. However, since the OA gain dynamics vary
with amplifier types, operating conditions and control schemes, the gain dynamics should be
carefully considered when applying the present test method to various OA. The manufacturer of
the OA should present data validating the required modulation frequency to limit the error to
<1 dB. The measurements for obtaining this information are described in Annex C.
The test method is described basically for multichannel applications, which includes single
channel applications as a special case of multichannel (wavelength-division multiplexed)
applications.
NOTE All numerical values followed by (‡) are currently under study.
2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
IEC 61291-1, Optical amplifiers – Part 1: Generic specification
3 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply:
AGC automatic gain control
ALC automatic level control
AOM acousto-optic modulator
APC automatic power control
ASE amplified spontaneous emission
CW continuous wave

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SIST EN 61290-10-1:2009
– 8 – 61290-10-1 © IEC:2009
DBR distributed Bragg reflector (laser diode)
DC direct current
DFB distributed feed-back (laser diode)
ECL external cavity laser (diode)
EDFA erbium-doped fibre amplifier
ER erbium
FWHM full width at half maximum
LED light emitting diode
LD laser diode
NF noise figure
OA optical amplifier
OSA optical spectrum analyzer
SW switch
4 Apparatus
The basic measurement set-up is given in Figure 1.

OA under test
Optical pulses
typical repetition rate
500 kHz to 1 000 kHz
Optical spectrum
Optical pulse
OA
SW
analyzer
source
Trigger
IEC  310/09

Figure 1 – Typical arrangement of the optical pulse test method
The test equipment needed, with the required characteristics, is listed below.
a) Optical pulse source: Two arrangements of the optical pulse source are possible as shown in
Figure 2. Optical pulse source a (Figure 2a) consists of CW optical sources with an external
optical switch and attenuator(s). Optical pulse source b (Figure 2b) consists of directly
modulated optical sources and attenuator(s).
Optical pulse source

Optical attenuator(s)
Optical sources
operating at CW
dB
Optical switch
IEC  311/09

Figure 2a – Arrangement with external optical switch

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SIST EN 61290-10-1:2009
61290-10-1 © IEC:2009 – 9 –

Optical pulse source
Optical attenuator(s)
Optical sources
pulsated by direct
modulation dB
IEC  312/09

Figure 2b – Arrangement with directly modulated optical source

Figure 2 – Two arrangements of the optical pulse source
Unless otherwise specified, the full width at half maximum (FWHM) of the output spectrum of
optical pulse source a or b shall be narrower than 0,1 nm (‡) so as not to cause any
interference to adjacent channels. In the case of a single-channel source, it shall be
narrower than 1 nm (‡). Distributed feedback (DFB) lasers, distributed Bragg reflection (DBR)
lasers, and external cavity lasers (ECLs), for example, are applicable. The suppression ratio
of the side modes of these DFB lasers shall be higher than 30 dB (‡). The output power
fluctuation shall be less than 0,05 dB (‡), which may be more easily attainable with an optical
isolator placed at the output port of each source.
Optical pulse source a simultaneously pulsates wavelength-division multiplexed light with an
optical switch, where the switching time is common to all the channels; timing adjustment is
not needed. Moreover, frequency chirping and spontaneous emission can be minimum; the
extinction ratio of the "on" versus "off" stages can be uniquely determined at a high level if a
high extinction-ratio switch is used. An acousto-optic modulator (AOM) is typically used as
the switch.
For optical pulse source b, the leakage power at the off-state should be as small as possible
to minimize the measurement error, although calibration is possible by subtracting the
leaked power. This may demand a zero-bias operation of laser diode sources. Moreover,
care must be taken in synchronizing optical pulses because the pulse timing may differ from
one source to another.
b) Variable optical attenuator: The attenuation range and stability shall be over 40 dB (‡) and
better than ± 0,1 dB (‡), respectively. The reflectance from this device shall be smaller than
−40 dB (‡) at each port. The variable optical attenuator may be incorporated in the optical
pulse source.
c) Optical switch: This device shall have a polarization sensitivity less than ± 0,1 dB (‡), static
isolation better than 65 dB (‡), transition time less than 50 ns (‡), and switching delay time
less than 2 ms (‡). The reflectance from this device shall be smaller than –40 dB (‡) at each
port. Figure 3 defines the optical switch static isolation. The optical switch is not required for
optical pulse source b.
Switching signal

Output
pulse
Power
Light
SW
meter
source
P
IEC  313/09 off -state
 ISO =
static
P
on-state
Figure 3 – Static isolation of an optical switch
d) Pulse generator: This device is used to drive optical pulse sources and the optical sampling
switch. When using an internally modulated optical pulse source, an independent pulse
generator is not required. Pulse train(s) shall be generated with a pulse interval of, typically,
1 μs to 2 μs (‡). The pulse widths shall be adjustable from 100 ns to 2 ms (‡) with a step of
5 ns or finer. The delay shall be adjustable at least from 100 ns to 4 μs (‡) in steps of 5 ns or

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SIST EN 61290-10-1:2009
– 10 – 61290-10-1 © IEC:2009
finer. The rise time and fall time, t and t , of the output optical pulse shall be less than 10 ns
r f
(‡). Definitions of t and t are given in Figure 4.
r f
1

SW
output
10 % pulse
to

90 %
0
Time
t
f
t
r
IEC  314/09

Figure 4 – Definitions of rise time and fall time, t and t of optical pulses
r f
e) Optical spectrum analyzer: This device shall have polarization sensitivity less than
0,1 dB (‡), stability better than ±0,1 dB (‡),wavelength accuracy better than ±0,5 nm (‡), and
wavelength reproducibility better than 0,01 nm (‡). The device shall have a measurement
range at least from –75 dBm to +20 dBm (‡) with a resolution better than 0,1 nm (‡). The
reflectance from this device shall be smaller than –40 dB (‡) at its input port.
f) Optical power meter: This device shall have a measurement accuracy better than ±0,2 dB
(‡), irrespective of the state of the input light polarization, within the operational wavelength
band of the OA and within a power range from –40 dBm to +20 dBm (‡).
g) Optical connectors: The connection loss repeatability shall be better than ±0,1 dB (‡). The
reflectance from this device shall be smaller than –40 dB (‡).
h) Optical fibre jumpers: The mode field diameter of the optical fibre jumpers shall be as close
as possible, so as not to cause excessive loss and reflectance, to that of fibres used as input
and output ports of the OA. The reflectance from optical fibre jumpers shall be smaller than
–40 dB (‡), and the device length shall be short (<2 m).
5 Test sample
The OA shall operate at nominal operating conditions. If the OA is likely to cause laser
oscillations due to unwanted reflections, optical isolators should be used to bracket the OA
under test. This will minimize the signal instability and the measurement inaccuracy.
Care shall be taken in the state of polarization of the input light during the measurement.
Changes in the polarization state of the input light may result in input optical power changes
because of the slight polarization dependency expected from all the optical components used,
leading to measurement errors.
6 Procedure
The test procedure consists of four parts:
a) initial system setting and calibration;
b) sampling window adjustment;
c) OA measurement and
d) calculation.

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SIST EN 61290-10-1:2009
61290-10-1 © IEC:2009 – 11 –
The measurement flow is given in Figure 5. This procedure enables self-consistent calculation of
not only OA noise factor but also ASE power and signal gain.

Start
Initial system setting
λ to λ
1 N
Initial calibration
OA setting
Sampling window
adjustment for OA
OA parameter setting
λ to λ
1 N
Measurement
Calculation
and printout
Parameter change
IEC  315/09

Figure 5 – Measurement flow chart
6.1 Calibration
6.1.1 Calibration of OSA power measurement
Calibrate the OSA power measurement by using a calibrated power meter.
NOTE The calibrated optical power meter detects all the optical power including source spontaneous emission,
whereas the OSA measurement detects just the optical power within the resolution bandwidth of the OSA. Therefore,
use of an optical filter with a FWHM passband of 1 nm to 3 nm is recommended at the output of the optical pulse source
to increase the calibration accuracy.
6.1.2 Calibration of the pulse duty ratio
Follow the steps below to calibrate the pulse duty ratio.
a) Activate any one channel of the optical pulse source at CW and the specified power and
wavelength.
b) Set the pulse width T and the pulse interval T of the optical pulse source output as
source
specified in the product specification. T and T shall be sufficiently shorter than the
source
gain-response time of the OA under test. For EDFAs, T and T are typically 0,4 μs (‡)
source

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SIST EN 61290-10-1:2009
– 12 – 61290-10-1 © IEC:2009
and 1 μs (‡), respectively. These values, however, depend on the amplifier saturation
condition.
NOTE Measurement accuracy versus pulse rates is given in informative Annex B. EDFA output waveforms for
various EDFAs are given in informative Annex A.
c) Measure the average output power, P , with a power meter.
pulse-ave
d) Drive the optical pulse source with 100 % duty pulse (DC drive), and measure the output
power, P , with a power meter.
DC
e) Calculate the equivalent duty ratio by using Equation (1).

P
pulse-ave
DR = (1)
source
P
DC
NOTE For the optical pulse source using an external optical switch, the calibration result is applicable to the
other channels.
For the optical pulse source using direct modulation, the calibration shall be repeated for all the
channels, because the optical-pulse shape generated by each source can be different.
6.1.3 Calibration of the sampling module
Follow the steps below to calibrate the sampling modul
...