IEC 60793-1-47:2017

Optical fibres - Part 1-47: Measurement methods and test procedures - Macrobending loss

IEC 60793-1-47:2017 establishes uniform requirements for measuring the macrobending loss of single-mode fibres (class B) at 1 550 nm or 1 625 nm, category A1 multimode fibres at 850 nm or 1 300 nm, and category A3 and A4 multimode fibres at 650 nm, 850 nm or 1 300 nm, thereby assisting in the inspection of fibres and cables for commercial purposes. This document gives two methods for measuring macrobending sensitivity:
- Method A – Fibre winding, pertains to class B single-mode fibres and category A1 multimode fibres.
- Method B – Quarter circle bends, pertains to category A3 and A4 multimode fibres.
For both of these methods, the macrobending loss can be measured utilizing general fibre attenuation techniques, for example the power monitoring technique (see Annex A) or the cut‑back technique (see Annex B). Methods A and B are expected to produce different results if they are applied to the same fibre. This is because the key difference between the two methods is the deployment, including the bend radius and length of fibre that is bent. The reason for the difference is that A3 and A4 multimode fibres are expected to be deployed in short lengths with a smaller number of bends per unit fiber length compared to single-mode and category A1 multimode fibres. In this document, the "curvature radius" is defined as the radius of the suitable circular shaped support (e.g. mandrel or guiding groove on a flat surface) on which the fibre can be bent. In addition, informative Annex E has been added to approximate bend loss for class B single-mode fibres across a broad wavelength range at various effective bends. This fourth edition cancels and replaces the third edition published in 2009. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- former Annex A has been renumbered to Annex D;
- introduction of new Annex A on the transmitted power monitoring technique;
- introduction of Annex B on the cut-back technique;
- introduction of Annex C on the requirements for the optical source characteristics of A1 multimode measurement;
- introduction of Annex E on parallel plate (2-point) macrobend loss approximation.
Keywords: macrobending loss of single-mode fibers

Fibres optiques - Partie 1-47: Méthodes de mesure et procédures d'essai - Pertes par macrocourbures

IEC 60793-1-47:2017 établit des exigences uniformes pour la mesure des pertes par macrocourbures pour les fibres optiques unimodales (classe B) à 1 550 nm ou 1 625 nm, pour les fibres multimodales de catégorie A1 à 850 nm ou 1 300 nm, et les fibres multimodales des catégories A3 et A4 à 650 nm, 850 nm ou 1 300 nm, contribuant ainsi au contrôle des fibres et câbles dans des relations commerciales. Le présent document décrit deux méthodes destinées à mesurer la sensibilité aux macrocourbures:
- Méthode A – Enroulement de fibre, se rapporte aux fibres unimodales de classe B et aux fibres multimodales de catégorie A1.
- Méthode B – Courbures d'un quart de cercle, se rapporte aux fibres multimodales de catégories A3 et A4.
Pour les deux méthodes, les pertes par macrocourbures peuvent être mesurées par des techniques générales d'affaiblissement des fibres, par exemple la technique de mesure de la puissance (voir Annexe A) ou la technique de la fibre coupée (voir Annexe B). Les méthodes A et B sont susceptibles de produire des résultats différents si elles sont appliquées à la même fibre. Ceci est dû au fait que la différence fondamentale entre les deux méthodes réside dans la façon de les déployer, comprenant à la fois le rayon de courbure et la longueur de fibre courbée. La raison de cette différence repose sur le fait que les fibres multimodales des catégories A3 et A4 sont conçues pour être installées sur de petites longueurs et avec un faible nombre de courbures par unité de longueur de fibre par rapport aux fibres unimodales et aux fibres multimodales de la catégorie A1. Dans le présent document, le "rayon de courbure" est défini comme le rayon du support adapté de forme circulaire (par exemple, un mandrin ou une rainure de guidage sur une surface plane) sur lequel la fibre peut être courbée. En outre, l'Annexe E (informative) a été ajoutée pour présenter une approximation des pertes par courbures pour des fibres unimodales de classe B sur une large plage de longueurs d'onde pour différentes courbures effectives. Cette quatrième édition annule et remplace la troisième édition publiée en 2009 dont elle constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- l'Annexe A a été renumérotée Annexe D;
- une nouvelle Annexe A portant sur la technique de la mesure de la puissance transmise a été introduite;
- l'Annexe B portant sur la technique de la fibre coupée a été introduite;
- l'Annexe C portant sur les exigences relatives aux caractéristiques des sources optiques pour une mesure des fibres multimodales de catégorie A1 a été introduite;
- l'Annexe E portant sur l'approximation des pertes par macrocourbures utilisant des plaques parallèles (deux points) a été introduite.
Mots clés : macrocourbures pour les fibres optiques unimodales

General Information

• Status: Published
• Publication Date: 10-Oct-2017
• 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: 03-Nov-2017
• Completion Date: 11-Oct-2017

Relations

• Revises: IEC 60793-1-47:2009 - Optical fibres - Part 1-47: Measurement methods and test procedures - Macrobending loss
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60793-1-47 ®
Edition 4.0 2017-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibres –
Part 1-47: Measurement methods and test procedures – Macrobending loss

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
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IEC 60793-1-47 ®
Edition 4.0 2017-10
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibres –
Part 1-47: Measurement methods and test procedures – Macrobending loss

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.10 ISBN 978-2-8322-4960-4

– 2 – IEC 60793-1-47:2017 RLV © IEC 2017
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Apparatus . 9
4.1 Method A – Fibre winding . 9
4.2 Method B – Quarter circle bends . 9
4.3 Input system . 10
4.3.1 Optical source . 10
4.3.2 Optical launch arrangement . 10
4.4 Output system and detection . 13
4.4.1 Optical divider . 13
4.4.2 Optical detector . 13
4.4.3 Optical detection assembly . 13
4.4.4 Signal processing . 13
5 Specimen . 14
5.1 Specimen length . 14
5.1.1 Method A – Fibre winding . 14
5.1.2 Method B – Quarter circle bends. 14
5.2 Specimen end face . 14
6 Procedure . 14
6.1 Method A – Fibre winding . 14
6.1.1 General consideration . 14
6.1.2 Single-mode fibres . 14
6.1.3 Multimode (A1) fibres . 15
6.2 Method B – Quarter circle bends . 16
7 Calculations . 18
8 Results . 18
8.1 Information available with each measurement . 18
8.2 Information available upon request . 18
9 Specification information . 18
Annex A (normative) Change in transmittance by transmitted power technique . 20
A.1 Apparatus . 20
A.1.1 General . 20
A.2 Procedure . 21
A.3 Calculations . 21
Annex B (normative) Cut-back technique . 23
B.1 General . 23
B.2 Apparatus . 23
B.2.1 General apparatus for all fibres. 23
B.3 Procedure . 23
B.4 Calculations . 24
Annex C (normative) Requirements for the optical source characteristics for A1
multimode measurement . 25

C.1 Encircled flux (EF) . 25
C.2 Limits on encircled flux . 25
Annex D (informative) Small bend radius phenomena . 28
D.1 General . 28
D.2 Interference between propagating and radiating modes . 28
D.3 Polarization effects . 30
D.4 High power damage . 30
Annex E (informative) Parallel plate (2-point) macrobend loss approximation . 31
E.1 General . 31
E.2 Specimen . 31
E.3 Apparatus . 31
E.3.1 General . 31
E.3.2 Stepper motor control . 32
E.3.3 Movable plate . 32
E.3.4 Fixed plate . 32
E.4 Procedure . 33
E.5 Calculation . 33
E.6 Results . 33
E.7 Comparison of results with normative test . 34
Bibliography . 36

Figure 1 – Quarter circle guide groove in plate . 10
Figure 2 – General launch arrangement . 10
Figure 3 – Lens system . 12
Figure 4 – Launch fibre . 12
Figure 5 – Mode scrambler (for A4 fibre) . 12
Figure 6 – Multiple bends using stacked plates . 17
Figure A.1 – Measurement of change in optical transmittance using reference
specimen . 20
Figure A.2 – Measurement of change in optical transmittance using stabilized source . 21
Figure B.1 – Arrangement of equipment to perform loss measurement at one specified
wavelength . 23
Figure B.2 – Arrangement of equipment used to obtain a loss spectrum . 23
Figure C.1 – Encircled flux template example . 26
Figure D.1 – Loss curves versus curve fits . 29
Figure E.1 – Schematic of possible (two-point bend) apparatus . 32
Figure E.2 – Example of applying an exponential fit to the spectral data of a B6_a2
fibre . 34
Figure E.3 – Example of 2-point bend test data for a B6_a2 fibre . 34

Table 1 – Launch conditions for A2 to A4 fibres . 13
Table C.1 – Threshold tolerance . 26
Table C.2 – EF requirements for 50 µm core fibre cabling at 850 nm . 27
Table C.3 – EF requirements for 50 µm core fibre cabling at 1 300 nm . 27
Table C.4 – EF requirements for 62,5 µm core fibre cabling at 850 nm . 27
Table C.5 – EF requirements for 62,5 µm core fibre cabling at 1 300 nm . 27

– 4 – IEC 60793-1-47:2017 RLV © IEC 2017
Table E.1 – Comparison of parallel plate (2-point) versus method A macrobend loss
measurement for a B6_b3 fibre at 10 mm diameter (ratio of mandrel / 2-point). 35

IN
...

IEC 60793-1-47 ®
Edition 4.0 2017-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-47: Measurement methods and test procedures – Macrobending loss

Fibres optiques –
Partie 1-47: Méthodes de mesure et procédures d'essai – Pertes par
macrocourbures
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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IEC 60793-1-47 ®
Edition 4.0 2017-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 1-47: Measurement methods and test procedures – Macrobending loss

Fibres optiques –
Partie 1-47: Méthodes de mesure et procédures d'essai – Pertes par

macrocourbures
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-4865-2

– 2 – IEC 60793-1-47:2017 © IEC 2017
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Apparatus . 9
4.1 Method A – Fibre winding . 9
4.2 Method B – Quarter circle bends . 9
4.3 Input system . 10
4.3.1 Optical source . 10
4.3.2 Optical launch arrangement . 10
4.4 Output system and detection . 12
4.4.1 Optical divider . 12
4.4.2 Optical detector . 12
4.4.3 Optical detection assembly . 13
4.4.4 Signal processing . 13
5 Specimen . 13
5.1 Specimen length . 13
5.1.1 Method A – Fibre winding . 13
5.1.2 Method B – Quarter circle bends. 13
5.2 Specimen end face . 13
6 Procedure . 13
6.1 Method A – Fibre winding . 13
6.1.1 General consideration . 13
6.1.2 Single-mode fibres . 14
6.1.3 Multimode (A1) fibres . 15
6.2 Method B – Quarter circle bends . 15
7 Calculations . 17
8 Results . 17
8.1 Information available with each measurement . 17
8.2 Information available upon request . 17
9 Specification information . 17
Annex A (normative) Change in transmittance by transmitted power technique . 19
A.1 Apparatus . 19
A.1.1 General . 19
A.2 Procedure . 20
A.3 Calculations . 20
Annex B (normative) Cut-back technique . 22
B.1 General . 22
B.2 Apparatus . 22
B.2.1 General apparatus for all fibres. 22
B.3 Procedure . 22
B.4 Calculations . 23
Annex C (normative) Requirements for the optical source characteristics for A1
multimode measurement . 24

C.1 Encircled flux (EF) . 24
C.2 Limits on encircled flux . 24
Annex D (informative) Small bend radius phenomena . 27
D.1 General . 27
D.2 Interference between propagating and radiating modes . 27
D.3 Polarization effects . 29
D.4 High power damage . 29
Annex E (informative) Parallel plate (2-point) macrobend loss approximation . 30
E.1 General . 30
E.2 Specimen . 30
E.3 Apparatus . 30
E.3.1 General . 30
E.3.2 Stepper motor control . 31
E.3.3 Movable plate . 31
E.3.4 Fixed plate . 31
E.4 Procedure . 32
E.5 Calculation . 32
E.6 Results . 32
E.7 Comparison of results with normative test . 33
Bibliography . 35

Figure 1 – Quarter circle guide groove in plate .
...