SIST EN IEC 62129-3:2019

SLOVENSKI STANDARD
SIST EN IEC 62129-3:2019
01-oktober-2019
Umerjanje valovno-dolžinskih/optično-frekvenčnih merilnih instrumentov - 3. del:
Merilniki optične frekvence z notranjo referenco na frekvenčni glavnik (IEC 62129-
3:2019)
Calibration of wavelength/optical frequency measurement instruments - Part 3: Optical
frequency meters internally referenced to a frequency comb (IEC 62129-3:2019)
Kalibrierung von Messgeräten für die Wellenlänge/optische Frequenz –Teil 3: Optisches
Frequenzmessgerät mit internem Bezug auf einen Frequenzkamm (IEC 62129-3:2019)
Étalonnage des appareils de mesure de longueur d'onde/appareil de mesure de la
fréquence optique - Partie 3: Fréquencemètres optiques faisant référence en interne à
un peigne de fréquence (IEC 62129-3:2019)
Ta slovenski standard je istoveten z: EN IEC 62129-3:2019
ICS:
17.180.30 Optični merilni instrumenti Optical measuring
instruments
33.180.01 Sistemi z optičnimi vlakni na Fibre optic systems in
splošno general
SIST EN IEC 62129-3:2019 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 62129-3:2019

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SIST EN IEC 62129-3:2019


EUROPEAN STANDARD EN IEC 62129-3

NORME EUROPÉENNE

EUROPÄISCHE NORM
July 2019
ICS 33.180.01

English Version
Calibration of wavelength/optical frequency measurement
instruments - Part 3:Optical frequency meters internally
referenced to a frequency comb
(IEC 62129-3:2019)
Étalonnage des appareils de mesure de longueur Kalibrierung von Messgeräten für die Wellenlänge/optische
d'onde/appareil de mesure de la fréquence optique - Partie Frequenz -Teil 3: Optisches Frequenzmessgerät mit
3: Fréquencemètres optiques faisant référence en interne à internem Bezug auf einen Frequenzkamm
un peigne de fréquence (IEC 62129-3:2019)
(IEC 62129-3:2019)
This European Standard was approved by CENELEC on 2019-06-24. 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
© 2019 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 62129-3:2019 E

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SIST EN IEC 62129-3:2019


EN IEC 62129-3:2019 (E)

European foreword
The text of document 86/551/FDIS, future edition 1 of IEC 62129-3, prepared by IEC/TC 86 "Fibre optics" was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 62129-3:2019.
The following dates are fixed:
• latest date by which the document has to be implemented at national level by (dop) 2020-03-24
publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-06-24
document have to be withdrawn

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 62129-3:2019 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 62129-1 NOTE Harmonized as EN 62129-1
IEC 62129-2:2011 NOTE Harmonized as EN 62129-2:2011 (not modified)
ISO/IEC 17025 NOTE Harmonized as EN ISO/IEC 17025
IEC 61315 NOTE Harmonized as EN IEC 61315
IEC 60359 NOTE Harmonized as EN 60359

2

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SIST EN IEC 62129-3:2019


EN IEC 62129-3:2019 (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- -
specifications - Sectional specification for 50
class B single-mode fibres
IEC 60825-1 -  Safety of laser products - Part 1: Equipment EN 60825-1 -
classification and requirements
IEC 60825-2 -  Safety of laser products - Part 2: Safety of EN 60825-2 -
optical fibre communication systems (OFCS)
IEC/TR 61931 -  Fibre optic - Terminology - -
ISO/IEC Guide 98-3 2008 Uncertainty of measurement - Part 3: Guide - -
to the expression of uncertainty in
measurement (GUM:1995)

3

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SIST EN IEC 62129-3:2019




IEC 62129-3

®


Edition 1.0 2019-05




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Calibration of wavelength / optical frequency measurement instruments –

Part 3: Optical frequency meters internally referenced to a frequency comb




Étalonnage des appareils de mesure de longueur d'onde / appareil de mesure de

la fréquence optique –

Partie 3: Fréquencemètres optiques faisant référence en interne à un peigne de


fréquence













INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 33.180.01 ISBN 978-2-8322-6922-0




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 62129-3:2019
– 2 – IEC 62129-3:2019  IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Calibration test requirements . 8
4.1 Organization . 8
4.2 Traceability . 8
4.3 Preparation . 8
4.4 Reference calibration conditions . 8
5 Optical frequency calibration . 8
5.1 Establishing the calibration conditions . 8
5.2 Calibration procedure . 9
5.2.1 General . 9
5.2.2 Measurement configuration . 9
5.2.3 Detailed procedure . 10
5.3 Calibration uncertainty . 10
5.4 Reporting the results . 11
6 Absolute power calibration . 11
Annex A (normative) Mathematical basis for measurement uncertainty calculations . 12
A.1 General . 12
A.2 Type A evaluation of uncertainty . 12
A.3 Type B evaluation of uncertainty . 12
A.4 Determining the combined standard uncertainty . 13
A.5 Reporting . 14
Annex B (informative) Measurement method for the frequency of a stabilized laser
with an optical frequency comb . 15
Annex C (informative) Examples of stabilized optical frequency comb source . 17
C.1 Method A (pump pulse source and nonlinear optical effect) . 17
C.2 Method B (stabilized laser and electro-optical modulator) . 17
Annex D (normative) Frequency-dependence of uncertainty . 19
Bibliography . 20

Figure 1 – Optical frequency meter measurement using a reference source . 9
Figure 2 – Optical frequency meter measurement using a reference optical frequency
meter . 10
Figure B.1 – Schematic configuration of optical frequency measurement technique
using an optical comb . 15
Figure B.2 – Optical spectra of lasers and optical frequency combs . 16
Figure C.1 – Pump pulse source and nonlinear optical effect . 17
Figure C.2 – Electro-optical modulator type comb source . 18

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SIST EN IEC 62129-3:2019
IEC 62129-3:2019  IEC 2019 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

CALIBRATION OF WAVELENGTH /
OPTICAL FREQUENCY MEASUREMENT INSTRUMENTS –

Part 3: Optical frequency meters internally
referenced to a frequency comb

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62129-3 has been prepared by IEC technical committee 86: Fibre
optics.
This first edition cancels and replaces IEC TS 62129-3, published in 2014.
This edition includes the following significant technical changes with respect to the previous
edition:
a) text has been added to 5.2.3 about calibration at a second optical frequency;
b) Annex D is now normative;
c) Subclause 4.2 has been improved;
d) measurement method of frequency has been moved to Annex B;
e) example of optical frequency comb has been moved to Annex C;
f) frequency-dependence uncertainty has been moved to Annex D.

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SIST EN IEC 62129-3:2019
– 4 – IEC 62129-3:2019  IEC 2019
The text of this International Standard is based on the following documents:
FDIS Report on voting
86/551/FDIS 86/554/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.
A list of all parts in the IEC 62129 series, published under the general title Calibration of
wavelength/optical frequency measurement instruments, 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.

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SIST EN IEC 62129-3:2019
IEC 62129-3:2019  IEC 2019 – 5 –
INTRODUCTION
It is essential for realizing fibre optic systems that optical channels are defined in the optical
frequency domain, not the wavelength domain. One example: the anchor frequency of the ITU-
T grid is 193,1 THz, and the channel spacings of the ITU-T grid are 12,5 GHz, 25 GHz, 50 GHz,
1
and 100 GHz [1] .
ITU-T has also discussed λ-interface systems such as "black link" [2]. "Black link" includes
WDM MUX/DEMUX and a transmission fibre, and provides λ-interfaces. Especially in DWDM
systems (channel spacing < 100 GHz), the uncertainty in specifying optical frequency needs to
be minimized.
To implement future telecom systems, it is expected that optical frequency measurements will
need to be extremely precise. For example, to achieve the channel spacing of 25 GHz, signal
optical frequency uncertainty (Uf ) and required measurement uncertainty (Uf ) need to be
sig meas
-5 -6 -6 -8
2 GHz to 200 MHz (Uf / f = 10 to 10 ) and 200 MHz to 2 MHz (Uf / f = 10 to 10 ),
sig meas
respectively. Unfortunately, conventional wavelength meters have measurement uncertainties
-6 -7
of 10 to 10 . The solution is to use optical frequency measurements since measurement
-9
uncertainties can be as small as 10 , which satisfies the above telecom requirement
-6 -8
(Uf / f = 10 to 10 ). Therefore, an optical frequency measurement scheme is necessary
meas
for the calibration of future telecom systems.
The frequency meter to calibrate with the procedure described in this document is the
measurement equipment internally utilizing the optical frequency comb. In Annex A, the
mathematical basis for the uncertainty of measurement is described. The measurement
procedure of the frequency with the frequency meter utilizing the optical frequency comb is
shown in Annex B and the example of the optical frequency comb sources are shown in Annex C.
Additionally, the uncertainty depending on the frequency is shown in Annex D.
This document defines all the steps involved in the calibration process of the frequency
measuring with the optical frequency meter internally utilizing an optical frequency comb:
establishing the calibration conditions, carrying out the calibration, calculating the uncertainty,
and reporting the uncertainty, the calibration conditions and the traceability.


____________
1
Numbers in square brackets refer to the Bibliography.

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– 6 – IEC 62129-3:2019  IEC 2019
CALIBRATION OF WAVELENGTH /
OPTICAL FREQUENCY MEASUREMENT INSTRUMENTS –

Part 3: Optical frequency meters internally
referenced to a frequency comb



1 Scope
This part of IEC 62129 describes the calibration of optical frequency meters using an optical
frequency comb as an internal reference. It is applicable to instruments measuring the optical
frequency emitted from sources that are typical for the fibre-optic communications industry. It
is assumed that the optical radiation will be coupled to the optical frequency meter by a single-
mode optical fibre. This document is part of the IEC 62129 series on the calibration of
wavelength/optical frequency measurement instruments. Refer to IEC 62129-1 [3] for the
calibration of optical spectrum analyzers, and refer to IEC 62129-2 [4] for calibration of
Michelson interferometer single wavelength meters.
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 60825-1, Safety of laser products – Part 1: Equipment classification and requirements
IEC 60825-2, Safety of laser products – Part 2: Safety of optical fibre communication systems
(OFCS)
IEC TR 61931, Fibre optic – Terminology
ISO/IEC Guide 98-3:2008, Uncertainty of measurement – Part 3: Guide to the expression of
uncertainty in measurement (GUM:1995)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC TR 61931, and the
following 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 62129-3:2019
IEC 62129-3:2019  IEC 2019 – 7 –
3.1
accredited calibration laboratory
calibration laboratory authorized by the appropriate national organization to issue calibration
certificates with a minimum specified uncertainty, which demonstrate traceability to national
measurement standards (3.3)
3.2
calibration
set of operations that establish, under specified conditions, the relationship between the values
of quantities indicated by a measuring instrument and the corresponding values realized by
measurement standards
Note 1 to entry: The result of a calibration permits either the assignment of values of measurands to the indications
or the determination of corrections with respect to indications.
Note 2 to entry: A calibration may also determine other metrological properties such as the effect of influence
quantities.
Note 3 to entry: The result of a calibration may be recorded in a document, sometimes called a calibration certificate
or a calibration report.
[SOURCE: ISO/IEC Guide 99:2007 [5], 2.39, modified – Only the first part of the definition has
been used and the notes to entry have been modified.]
3.3
national measurement standard
standard recognized by a national decision to serve, in a country, as the basis for assigning
values to other standards for the quantity concerned
[ISO/IEC Guide 99:2007, 5.3, modified – Some terms have been replaced with similar meaning.]
3.4
reference standard
standard, generally having the highest metrological quality available at a given location or in a
given organization, from which measurements made therein are derived
Note 1 to entry: The general definition of this term is described in ISO/IEC Guide 99:2007, 5.6.
3.5
traceability
property of the result of a measurement or the value of a measurement standard whereby it can
be related to stated references, usually national or international measurement standards,
through an unbroken chain of comparisons all having stated uncertainties
Note 1 to entry: The general definition of this term is described in ISO/IEC Guide 99:2007, 2.41.
3.6
traceability chain
unbroken chain of comparison
Note 1 to entry: The general definition of this term is described in ISO/IEC Guide 99:2007, 2.42.
3.7
working standard
measurement standard that is used routinely to calibrate or check measuring instruments
Note 1 to entry: A working standard is usually calibrated against a reference standard.
Note 2 to entry: The general definition of this term is described in ISO/IEC Guide 99:2007, 5.7.

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– 8 – IEC 62129-3:2019  IEC 2019
4 Calibration test requirements
4.1 Organization
The calibration laboratory should ensure that suitable requirements for calibration are followed.
NOTE Guidance about good practices for calibration can be found in ISO/IEC 17025 [6].
There shall be a documented measurement procedure for each type of calibration performed,
giving step-by-step operating instructions and equipment to be used.
4.2 Traceability
The calibration laboratory should ensure that suitable requirements for traceability are followed.
NOTE Guidance about good practices for traceability can be found in ISO/IEC 17025.
Make sure that any test equipment which has a significant influence on the calibration results
is calibrated. Upon request, specify this test equipment and its calibration chain(s). The
recalibration period(s) shall be defined and documented.
4.3 Preparation
The environmental conditions shall be commensurate with the degree of uncertainty that is
required for calibration:
a) the environment shall be clean;
b) temperature monitoring and control is required;
c) all laser sources shall be safely operated (refer to IEC 60825-1 and to IEC 60825-2).
4.4 Reference calibration conditions
The reference calibration conditions usually include the following parameters and, if necessary,
their tolerance bands: date, temperature, relative humidity, displayed power level, displayed
optical frequency, fibre, (spectral) bandwidth and resolution bandwidth (spectral resolution) set.
Unless otherwise specified, use a single-mode optical fibre input pigtail as specified in
IEC 60793-2-50, having a length of at least 2 m.
The calibration should be made in a temperature-controlled environment. The recommended
temperature is 23 °C. Depending on the desired uncertainty, the temperature, atmospheric
pressure and humidity may need to be monitored during the measurement.
Operate the optical frequency meter in accordance with the manufacturer's specifications and
operating procedures. Where practical, select a range of test conditions and parameters which
emulate the actual field operating conditions of the optical frequency meter under test. Choose
these parameters so as to optimize the optical frequency meter's uncertainties, as specified by
the manufacturer's operating procedures.
NOTE The calibration results only apply to the set of test conditions used in the calibration process.
5 Optical frequency calibration
5.1 Establishing the calibration conditions
Establishing and maintaining the calibration conditions is an important part of the calibration,
because any change of these conditions is capable of producing erroneous measurement
results. The calibration conditions should be a close approximation to the intended operating
conditions. This ensures that the (additional) uncertainty in the operating environment is as
small as possible. The calibration conditions should be specified in the form of nominal values

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SIST EN IEC 62129-3:2019
IEC 62129-3:2019  IEC 2019 – 9 –
with uncertainties when applicable. In order to meet the requirements of this document, the
calibration conditions shall at least consist of:
a) date of calibration;
b) ambient temperature, for example 23 °C. The temperature may need to be monitored
continuously to ensure that it remains within the requisite limits;
c) ambient relative humidity, for example 30 % to 70 %. The ambient relative humidity may
need to be monitored continuously to ensure that it remains within the requisite limits. A
relative humidity below the condensation point is assumed by default;
d) input optical power (that has to fall within the allowable specification for the optical
frequency meters);
e) if a transition locked source is used, then the quality of the lock shall be continuously
monitored during the measurements; a lock indicator can be sufficient.
The above conditions may not be exhaustive. There might be other parameters that have a
significant influence on the calibration uncertainty.
5.2 Calibration procedure
5.2.1 General
The main steps of the calibration procedure are as follows:
a) establish and record the appropriate calibration conditions (see 5.1). Switch on all
instrumentation and wait until it stabilizes;
b) set up the reference source in accordance with condition 5.1 d);
c) set up the instrument state of the test optical frequency meter according to the instruction
manual. Select appropriate units;
d) record the instrument states of the optical frequency meter.
5.2.2 Measurement configuration
Two possible configurations can be used for calibration. One uses
...