IEC 60793-1-43:2015

Optical fibres - Part 1-43: Measurement methods and test procedures - Numerical aperture measurement

IEC 60793-1-43:2015 establishes uniform requirements for measuring the numerical aperture of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes. The numerical aperture (NA) of categories A1, A2, A3 and A4 multimode fibre is an important parameter that describes a fibre's light-gathering ability. It is used to predict launching efficiency, joint loss at splices, and micro/macrobending performance. The numerical aperture is defined by measuring the far-field pattern (NAff). In some cases the theoretical numerical aperture (NAth) is used in the literature, which can be determined from measuring the difference in refractive indexes between the core and cladding. Ideally these two methods should produce the same value. This second edition of IEC 60793-1-43, together with other standards in the IEC 60793-4X series, cancels and replaces the first edition of IEC 60793-1-43, published in 2001, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- expansion of the scope to include A1, A2, A3 and A4 multimode fibre categories;
- addition of measurement parameters of sample length and threshold values, product specific to the variables that are now found in the product specifications;
- a new Annex B entitled "Product specific default values for NA measurement";
- addition of a new Technique 4 for measuring NA of A4d fibres;
- a new Annex A entitled "Mapping NA measurement to alternative lengths" that gives a mapping function to correlate shorter sample length measurements to the length suggested in the reference test method Naff. Keywords: numerical aperture of optical fibre, inspection of fibres and cables
This publication is to be read in conjunction with IEC 60793-1-1:2008, IEC 60793-1-21:2001  and IEC 60793-1-22:2001.

Fibres optiques - Partie 1-43: Méthodes de mesure et procédures d'essai - Mesure de l'ouverture numérique

IEC 60793-1-43:2015 établit des exigences uniformes pour mesurer l'ouverture numérique d'une fibre optique, contribuant ainsi au contrôle des fibres et câbles dans des relations commerciales. L'ouverture numérique (NA, numerical aperture) d'une fibre multimodale des catégories A1, A2, A3 et A4 est un paramètre important qui décrit la capacité de la fibre à capter le rayonnement lumineux. Il est utilisé pour prévoir l'efficacité de l'injection, les pertes aux épissures et la tenue aux microcourbures et aux macrocourbures. L'ouverture numérique est définie en mesurant le diagramme en champ lointain (NAff). Dans certains cas, l'ouverture numérique théorique (NAth) est utilisée dans la documentation. Elle peut être déterminée en mesurant la différence entre l'indice de réfraction du cœur et celui de la gaine. Idéalement, il convient que ces deux méthodes donnent la même valeur. Cette deuxième édition annule et remplace la première édition parue en 2001, dont elle constitue une révision technique. La présente édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
– élargissement du domaine d'application pour inclure les catégories A1, A2, A3 et A4 de fibres multimodales;
– ajout de paramètres de mesure de la longueur des échantillons et de valeurs seuils spécifiques aux produits, aux variables actuelles des spécifications de produit;
– une nouvelle Annexe B, "Valeurs par défaut spécifiques à un produit pour la mesure de l'ouverture numérique";
– ajout d'une nouvelle Technique 4, destinée à la mesure de l'ouverture numérique des fibres A4d;
– une nouvelle Annexe A, "Mise en correspondance de mesures d'ouvertures numériques avec des longueurs différentes" qui présente une fonction de mise en correspondance destinée à établir une relation entre des mesures sur des échantillons plus courts et la longueur proposée pour obtenir Naff par la méthode d'essai de référence.
Mots clés: l'ouverture numérique d'une fibre optique, contrôle des fibres et câbles

General Information

• Status: Published
• Publication Date: 26-Mar-2015
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: SC 86A - Fibres and cables
• Drafting Committee: WG 1 - TC 86/SC 86A/WG 1
• Current Stage: PPUB - Publication issued
• Start Date: 30-Jun-2015
• Completion Date: 27-Mar-2015

Relations

• Revises: IEC 60793-1-43:2001 - Optical fibres - Part 1-43: Measurement methods and test procedures - Numerical aperture
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60793-1-43 ®
Edition 2.0 2015-03
INTERNATIONAL
STANDARD
colour
inside
Optical fibres –
Part 1–43: Measurement methods and test procedures– Numerical aperture
measurement
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 15
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 60 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: [e-mail].
IEC 60793-1-43 ®
Edition 2.0 2015-03
INTERNATIONAL
STANDARD
colour
inside
Optical fibres –
Part 1–43: Measurement methods and test procedures– Numerical aperture

measurement
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.10 ISBN 978-2-8322-2545-5

– 2 – IEC 60793-1-43:2015 © IEC 2015
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references. 6
3 Overview of method . 6
4 Reference test method . 7
5 Apparatus . 8
5.1 Input system . 8
5.1.1 Light source . 8
5.1.2 Input optics . 8
5.1.3 Fibre input end support and alignment . 8
5.1.4 Cladding mode stripper . 8
5.2 Output system and detection . 8
5.2.1 General . 8
5.2.2 Technique 1 – Angular scan (see Figure 2) . 9
5.2.3 Technique 2 – Angular scan (see Figure 3) . 10
5.2.4 Technique 3 – Scan of the spatial field pattern (see Figure 4) . 10
5.2.5 Technique 4 – Inverse far-field measurement (see Figure 5, applicable
to subcategory A4d fibres). 12
6 Sampling and specimens . 13
6.1 Specimen length . 13
6.2 Specimen endface . 13
7 Procedure . 13
8 Calculations . 13
8.1 Far-field versus maximum theoretical value . 13
8.2 Threshold intensity angle, θ . 14
k
8.3 Numerical aperture, NA . 14
ff
8.4 Calculating far-field intensity pattern when using Technique 3 . 15
8.5 Calculating NA when using Technique 4 . 15
9 Results . 15
9.1 Information available with each measurement . 15
9.2 Information available upon request . 16
10 Specification information . 16
Annex A (informative) Mapping NA measurement to alternative lengths . 17
A.1 Introductory remark . 17
A.2 Mapping long length NA measurement to short length NA measurement . 17
ff ff
Annex B (normative) Product specific default values for NA measurement . 18
B.1 Introductory remark . 18
B.2 Table of default values used in NA measurement for multimode products . 18

Figure 1 – Representative refractive index profile for a graded index multimode fibre . 7
Figure 2 – Technique 1 – Angular scan . 9
Figure 3 –Technique 2 – Angular scan . 10
Figure 4 – Technique 3 – Scan of the spatial field pattern . 11

Figure 5 – Technique 4 – Inverse far-field method . 13
Figure 6 – Example of a far-field NA measurement . 14
Figure 7 – Sample output of an A4d fibre measured using Technique 4 . 15

Table B.1 – Default values for parameters used in the far-field NA measurement of
multimode fibres . 18

– 4 – IEC 60793-1-43:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRES –
Part 1–43: Measurement methods and test procedures–
Numerical aperture measurement

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60793-1-43 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition published in 2001, and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– expansion of the scope to include A1, A2, A3 and A4 multimode fibre categories;
– addition of measurement parameters of sample length and threshold values, product
specific to the variables that are now found in the product specifications;
– a new Annex B entitled "Product specific default values for NA measurement";
– addition of a new Technique 4 for measuring NA of A4d fibres;

– a new Annex A entitled "Mapping NA measurement to alternative lengths" that gives a
mapping function to correlate shorter sample length measurements to the length
suggested in the reference test method Na .
ff
This International Standard is to be used in conjunction with IEC 60793-1-1, IEC 60793-1-21
and IEC 60793-1-22.
The text of this standard is based on the following documents:
CDV Report on voting
86A/1566/CDV 86A/1622/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60793 series, published under the general title Optical fibres, can
be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
under
...

IEC 60793-1-43 ®
Edition 2.0 2015-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-43: Measurement methods and test procedures – Numerical aperture
Measurement
Fibres optiques –
Partie 1-43: Méthodes de mesure et procédures d'essai – Mesure de l'ouverture
numérique
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: [e-mail].
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Recherche de publications IEC - Electropedia - www.electropedia.org
webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au
La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en
en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans
comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire
projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary
Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais
Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des
Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées
antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.

Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
[e-mail].
IEC 60793-1-43 ®
Edition 2.0 2015-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-43: Measurement methods and test procedures – Numerical aperture

Measurement
Fibres optiques –
Partie 1-43: Méthodes de mesure et procédures d'essai – Mesure de l'ouverture

numérique
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-7387-6

– 2 – IEC 60793-1-43:2015 © IEC 2015
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Overview of method . 6
4 Reference test method . 7
5 Apparatus . 8
5.1 Input system . 8
5.1.1 Light source . 8
5.1.2 Input optics . 8
5.1.3 Fibre input end support and alignment . 8
5.1.4 Cladding mode stripper . 8
5.2 Output system and detection . 8
5.2.1 General . 8
5.2.2 Technique 1 – Angular scan (see Figure 2) . 9
5.2.3 Technique 2 – Angular scan (see Figure 3) . 10
5.2.4 Technique 3 – Scan of the spatial field pattern (see Figure 4) . 10
5.2.5 Technique 4 – Inverse far-field measurement (see Figure 5, applicable
to subcategory A4d fibres) . 12
6 Sampling and specimens . 13
6.1 Specimen length . 13
6.2 Specimen endface . 13
7 Procedure . 13
8 Calculations . 13
8.1 Far-field versus maximum theoretical value . 13
8.2 Threshold intensity angle, θ . 14
k
8.3 Numerical aperture, NA . 14
ff
8.4 Calculating far-field intensity pattern when using Technique 3 . 15
8.5 Calculating NA when using Technique 4 . 15
9 Results . 15
9.1 Information available with each measurement . 15
9.2 Information available upon request . 16
10 Specification information . 16
Annex A (informative) Mapping NA measurement to alternative lengths . 17
A.1 Introductory remark . 17
A.2 Mapping long length NA measurement to short length NA measurement . 17
ff ff
Annex B (normative) Product specific default values for NA measurement . 18
B.1 Introductory remark . 18
B.2 Table of default values used in NA measurement for multimode products . 18

Figure 1 – Representative refractive index profile for a graded index multimode fibre . 7
Figure 2 – Technique 1 – Angular scan . 9
Figure 3 –Technique 2 – Angular scan . 10
Figure 4 – Technique 3 – Scan of the spatial field pattern . 11

Figure 5 – Technique 4 – Inverse far-field method . 13
Figure 6 – Example of a far-field NA measurement . 14
Figure 7 – Sample output of an A4d fibre measured using Technique 4 . 15

Table B.1 – Default values for parameters used in the far-field NA measurement of
multimode fibres . 18

– 4 – IEC 60793-1-43:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRES –
Part 1-43: Measurement methods and test procedures–
Numerical aperture measurement

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Norm
...