IEC 61300-2-43:2014

Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 2-43: Tests - Screen testing of return loss of single-mode PC optical fibre connectors

IEC 61300-2-43:2014 aims at screening single-mode physical contact (PC) optical fibre connectors of an optical fibre cord or an optical fibre pigtail in terms of return loss, thus ensuring minimum return loss when the connectors, which have been screen tested by this method, are randomly mated with each other in the field. This second edition of IEC 61300-3-43 cancels and replaces the first edition published in 1999 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- revision of the scope;
- revision of the procedure;
- addition of measurement uncertainty into the 'Details to be specified';
- addition of a bibliography.
Keywords: single-mode physical contact (PC) optical fibre connectors, return loss

Dispositifs d'interconnexion et composants passifs à fibres optiques - Procédures fondamentales d'essais et de mesures - Partie 2-43: Essais - Sélection des connecteurs PC pour fibres optiques unimodales en fonction de leur affaiblissement de réflexion

L'IEC 61300-2-43:2014 a pour objet de décrire une sélection des connecteurs pour fibres optiques unimodales à contact physique (PC) montés sur un cordon à fibre optique ou une fibre amorce, en fonction de leur affaiblissement de réflexion, pour garantir ainsi un affaiblissement de réflexion minimal lorsque les connecteurs, qui ont été sélectionnés par cette méthode, sont accouplés sans choix préalable dans le terrain. Cette deuxième édition de l'IEC 61300-3-43 annule et remplace la première édition parue en 1999. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:^
- révision du domaine d'application;
- révision de la procédure;
- ajout de l'incertitude de mesure dans les 'Détails à spécifier';
- ajout d'une bibliographie.
Mots clés: connecteurs pour fibres optiques unimodales à contact physique (PC), affaiblissement de réflexion

General Information

• Status: Published
• Publication Date: 18-Jun-2014
• ICS: 33.180.20 - Fibre optic interconnecting devices
• Technical Committee: SC 86B - Fibre optic interconnecting devices and passive components
• Drafting Committee: WG 4 - TC 86/SC 86B/WG 4
• Current Stage: DELPUB - Deleted Publication
• Start Date: 01-Sep-2022
• Completion Date: 31-Dec-2020

Relations

• Revises: IEC 61300-2-43:1999 - Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 2-43: Tests - Screen testing of return loss of single mode PC optical fibre connectors
• Effective Date: 05-Sep-2023
• Revised: IEC 61300-2-43:2022 - Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 2-43: Tests - Screen testing of return loss of single-mode PC optical fibre connectors
• Effective Date: 05-Sep-2023

Overview

IEC 61300-2-43:2014 is an international standard published by the International Electrotechnical Commission (IEC) that specifies basic test and measurement procedures for fibre optic interconnecting devices and passive components. This part-Part 2-43-focuses specifically on the screen testing of return loss of single-mode physical contact (PC) optical fibre connectors. By providing a standardized procedure to test and screen optical fibre cords and pigtails, the standard ensures consistent and minimum return loss performance in fibre optic connections used globally.

This second edition supersedes the original 1999 version, incorporating updates to the scope, testing procedures, inclusion of measurement uncertainties, and an added bibliography.

Key Topics

• Return Loss Screening
  The primary objective of IEC 61300-2-43:2014 is to screen single-mode PC fibre connectors to guarantee minimum return loss during random mating. Return loss refers to the amount of signal light reflected back toward the source at a connector interface, which affects overall transmission quality.

• Physical Contact (PC) Connectors
  This standard addresses single-mode PC connectors with domed ferrule end faces that undergo a polishing process. The polishing creates a thin damaged layer on the fibre end face, which can lead to increased optical reflections and thus higher return loss.

• Measurement Procedure
  Testing involves using reflection standard plugs (RPs) in pairs, carefully selected to have superior return loss performance than the minimum designed level. This pair is used as a reference during the testing of cords or pigtails, ensuring that cords passing the test meet the required return loss criteria with over 99% certainty when randomly mated.

• Apparatus and Setups
  Measurement apparatus according to IEC 61300-3-6 is employed, including sources, detectors, branching devices, temporary joints, terminators, and reflection standard cords. Detailed setups illustrate how cords and pigtails should be connected and tested for accurate return loss screening.

• Measurement Uncertainty
  The standard includes specifications for accounting for measurement uncertainty to improve reliability and reproducibility of test results.

Applications

• Fibre Optic Manufacturing
  Manufacturers of single-mode PC fibre optic cords and pigtails use this standard to screen products during quality control, ensuring minimum return loss performance before shipment.

• Telecommunications
  Telecommunications companies rely on IEC 61300-2-43:2014 to ensure that fibre optic connectors achieve reliable low return loss, resulting in improved signal integrity and reduced incidences of signal reflection and interference.

• Network Installation and Maintenance
  Technicians and engineers performing fiber optic network deployments use the test procedures to verify connector quality prior to field installation, helping maintain high-performance communication systems.

• Research and Development
  R&D teams develop new optical connectors and fiber assemblies based on the test results and requirements defined by this standard to meet industry benchmarks for return loss.

Related Standards

• IEC 61300 Series
  IEC 61300 is a comprehensive series covering basic test and measurement procedures for fibre optic interconnecting devices and passive components. Part 3-6 (IEC 61300-3-6) focuses on examinations and measurements related to return loss, providing measurement techniques that complement the screening procedure detailed in Part 2-43.

• IEC 61754 Series
  This series defines fibre optic connector interfaces relevant to various connector types including PC connectors.

• ISO/IEC Directives
  The drafting and revision of IEC 61300-2-43 follow the ISO/IEC Directives, ensuring harmonization with international standards development processes.

Practical Value

By applying IEC 61300-2-43:2014, organizations ensure:

• Consistent Low Return Loss across optical fibre connections, improving optical network performance and reducing signal degradation.
• Standardized Testing Methods that enable manufacturers and users globally to speak the same 'quality language,' facilitating interoperability.
• Improved Reliability of single-mode PC fibre connectors, minimizing field failures caused by excessive reflections.
• Quality Assurance throughout the supply chain from production to installation and maintenance.

Utilizing this standard is essential for maintaining the integrity and performance of modern optical fibre networks that underpin critical communication infrastructures worldwide.

---

Keywords: single-mode physical contact optical fibre connectors, return loss testing, fibre optic cord screening, IEC 61300-2-43, optical fibre measurement standards, fibre optic test procedures.

Standards Content (Sample)

IEC 61300-2-43 ®
Edition 2.0 2014-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures –
Part 2-43: Tests – Screen testing of return loss of single-mode PC optical fibre
connectors
Dispositifs d’interconnexion et composants passifs à fibres optiques –
Procédures fondamentales d’essais et de mesures –
Partie 2-43: Essais – Sélection des connecteurs PC pour fibres optiques
unimodales en fonction de leur affaiblissement de réflexion

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IEC 61300-2-43 ®
Edition 2.0 2014-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and

measurement procedures –
Part 2-43: Tests – Screen testing of return loss of single-mode PC optical fibre

connectors
Dispositifs d’interconnexion et composants passifs à fibres optiques –

Procédures fondamentales d’essais et de mesures –

Partie 2-43: Essais – Sélection des connecteurs PC pour fibres optiques

unimodales en fonction de leur affaiblissement de réflexion

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX M
ICS 33.180.20 ISBN 978-2-8322-1640-8

– 2 – IEC 61300-2-43:2014 © IEC 2014
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 General description . 5
4 Apparatus . 5
5 Procedure . 6
5.1 Selection of the reflection standard cord . 6
5.2 Cord screen testing . 6
5.3 Pigtail cord screen testing . 6
6 Details to be specified . 7
Annex A (informative) Screen testing of return loss of pigtails having PC fibre optic
connector . 8
Bibliography . 13

Figure 1 – Measurement set-up for open plug reflection standard . 6
Figure 2 – Measurement set-up for mated reflection standard cords . 6
Figure 3 – Measurement set-up for cord screen testing . 6
Figure 4 – Measurement set-up for pigtail cord screen testing . 7
Figure A.1 – Measurement set-up of the screen test method . 9
Figure A.2 – Relationship between ß and α . 10
Figure A.3 – Cumulative probability of return loss before test . 11
Figure A.4 – Cumulative probability of return loss after test . 11
Figure A.5 – Relationship between power and α . 12
Figure A.6 – Measurement set-up of the reflected powers . 12

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC INTERCONNECTING DEVICES
AND PASSIVE COMPONENTS –
BASIC TEST AND MEASUREMENT PROCEDURES –

Part 2-43: Tests – Screen testing of return loss of
single-mode PC optical fibre connectors

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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 61300-3-43 has been prepared by subcommittee 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This second edition of IEC 61300-3-43 cancels and replaces the first edition published in
1999 and constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision of the scope;
b) revision of the procedure;
c) addition of measurement uncertainty into the 'Details to be specified';
d) addition of a bibliography.

– 4 – IEC 61300-2-43:2014 © IEC 2014
The text of this standard is based on the following documents:
CDV Report on voting
86B/3669/CDV 86B/3755/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 61300 series, published under the general title, Fibre optic
interconnecting and passive components – Basic test and measurement procedures, 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 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.
FIBRE OPTIC INTERCONNECTING DEVICES
AND PASSIVE COMPONENTS –
BASIC TEST AND MEASUREMENT PROCEDURES –

Part 2-43: Tests – Screen testing of return loss of
single-mode PC optical fibre connectors

1 Scope
This part of IEC 61300 aims at screening single-mode physical contact (PC) optical fibre
connectors of an optical fibre cord or an optical fibre pigtail in terms of return loss, thus
ensuring minimum return loss when the connectors, which have been screen tested by this
method, are randomly mated with each other in the field.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 61300-3-6, Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures – Part 3-6: Examinations and measurements – Return loss
3 General description
The domed ferrule end faces of PC connectors (not angled) are produced by a polishing
process. This polishing process results in a thin damaged layer at the fibre end face of the
connector. In silica fibres, the refractive index of the damaged layer is slightly higher than that
of original fibre. This high refractive index layer generates optical reflection. When PC
connectors are mated, return loss occurs as a result of multiple reflections at the two
damaged layers of the butted connectors.
This test procedure ensures that a designed minimum return loss is achieved when PC
connectors are randomly mated. It screens cords or pigtails by using a pair of reflection
standard plug (RP) cords. The pair of reflection standard plugs is selected on the condition
that the return loss when the plugs are mated is several decibels better than the designed
minimum return loss. Cords which pass this test will achieve the designed minimum return
loss in over 99 % of cases when randomly mated (see Annex A).
4 Apparatus
The equipment listed below shall be chosen according to the method used to measure the
connector return loss, in accordance with IEC 61300-3-6. The reflection standard plug shall
be prepared according to the procedure given in 5.1.
• Sources S
• Excitation unit E
• Detector D
• Temporary joint TJ
• Terminator T
• Branching device BD
• Reflection standard cord
– 6 – IEC 61300-2-43:2014 © IEC 2014
The reflection standard cord has a reflection standard plug (RP) at one end. The other end of
the reflection standard cord is an end or a plug whose return loss is better than the designed
minimum return loss L (in decibels).

rs
5 Procedure
5.1 Selection of the reflection standard cord
The reflection standard plug (RP) shall be selected by the following procedure.
a) Set up an objective reflection standard cord as shown in Figure 1.
TJ
S E BD
RP
D
14,7 dB
IEC  2022/14
Figure 1 – Measurement set-up for open plug reflection standard
b) Set the detector to 14,7 dB as the Fresnel reflection between the air and the silica fibre
core as shown in Figure 1. The refractive index of air is 1,0, and the one of silica fibre is
1,452 for single-mode fibre on condition ∆ = 0,3 %, λ = 1,31 µm.
NOTE Measurement accuracy can be improved by using the actual parameters of fibres which have been
employed.
c) Connect another objective reflection standard cord as shown in Figure 2, then measure
the return loss.
TJ
S E BD T T
RP RPRP
L + β (in decibels)
D rs
IEC  2023/14
Figure 2 – Measurement set-up for mated reflection standard cords
d) Take the pair of objective reflection standard cords as reflection standard cords on
condition that their return loss from the mating point is L + β (in decibels), where L is a

rs rs
designed minimum return loss. The value of β shall be set at above 2 dB.
5.2 Cord screen testing
a) Connect the device under test (DUT) (cord) between the reflection standard plugs as
shown in Figure 3.
TJ
S E BD DU T
T T
RP RP
D
L (in decibels)
r
IEC  2024/14
Figure 3 – Measurement set-up for cord screen testing
b) Measure the return loss L (in decibels) from the two PC mating points.
r
c) Consider the objective cord as a screen tested cord when L is greater than L .
r rs
5.3 Pigtail cord screen testing
a) Connect the objective PC connector of DUT (pigtail cord) to one reflection standard plug
as shown in Figure 4, and terminate pigtail fibre end.

TJ
S E BD DUT T T
RP
D L + α (in decibels)
rs
IEC  2025/14
Figure 4 – Measurement set-up for pigtail cord screen testing
b) Measure the return loss L (in decibels) from the mating point.
r
c) Pass the objective pigtail cord as a screen tested cord when L is greater than L + α (in

r rs
decibels). The value of α shall be set at above 0,6 dB and at less than 5 dB.
6 Details to be specified
The following details, as applicable, shall be specified in the relevant specification:
– minimum return loss L (in decibels);
rs
– condition of standard reflection plugs (the value of β in decibels);
– screening condition for pigtail cords (the value of α in decibels);
– attenuation of mating points between the reflection standard connectors and the objective
connectors;
– measurement uncertainty.
– 8 – IEC 61300-2-43:2014 © IEC 2014
Annex A
(informative)
Screen testing of return loss of pigtails
having PC fibre optic connector
This annex describes the theoretical background of the screen testing of return loss for
pigtails. The basic idea is the same as the screen testing of return loss of cords having PC
fibre optic connectors: select a pair of reference connectors, and a measurement pigtail is
screen tested using the reference connector under a condition which is determined by
simulation, where the distribution of high refractive index layer caused by polishing process is
considered.
Two parameters β and α are introduced into this method. Parameter β is used for the
selection of a pair of reference connectors. Parameter α is used as a criterion for screen
testing measurement connectors. These two parameters β and α are carefully determined by
simulation so that return loss of mating point exceeds certain specified return loss L with
rs
high probability when the screen tested connectors are randomly connected.
The method assumes:
– refractive index of fibre core n is 1,452;
– refractive index of air n is 1,0.
The set-up of the measurement and test procedures will be shown first. Figure A.1 shows the
set-up with the reference cords 1 and 2; 1a and 2a represent reference connectors. Points 3a
and 3b are the connectors of the cord under test and 4a is the connector of the pigtail under
test. The connectors represented by 1b and 2b and 5b are angled connectors with high return
loss. S is the optical source, D is the optical detector and BD represents the optical coupler. T
is a fibre termination which shall have a high return loss; it should be made by the application
of an index matching material to the fibre end or introducing an high attenuation in the fibre,
for example, with a mandrel wrap.

P0
Reference cord 1
S 1
BD
1a
5b 1b
P8
D
Adapter
Reference cord 2
Reference cord 1
2a 2b
P1
Adapter Adapter
Reference cord 2
Reference cord 1 Cord under test
3a 3b
2a
P2
Adapter
Pigtail under test
Reference cord 1
T
4a
P3
IEC  2026/14
Figure A.1 – Measurement set-up of the screen test method
P0 is the input power and P8, P1, P2 and P3 are the reflected powers. The symbols , , ,
 indicate connection conditions.
The procedure of the screen test method is as follows:
a) A pair of reference plugs is selected.
– Connect the connector 1b to the connector 5b, then measure the power P8 (see  in
Figure A.1).
– Connect the reference connector 2a to the reference connector 1a, then measure the
power P1 (see  in Figure A.1).
The condition of selection is given by:
< –10 log P1/P0 ≤ L + β (dB) (A.1)
L
rs rs
and n as follows:
The measured power P0 can be described using P8, n
1 2
–10 log 1/P0 = –10 log 1/P8 – 20 log (n – n ) / (n + n ) (A.2)
1 2 1 2
The second term of the right side represents Fresnel reflection of air, and equals 14,7 dB.
Therefore Equation (A.1) can be rewritten as:
0 < –10 log P1/P8 + 14,7 – L ≤ β (A.3)
rs
b) The cord under test is screen tested using the pair of reference connectors.
– Connect the cord under test 3 between the reference connectors 1a and 2a, then
measure the power P2 (see  in Figure A.1).

– 10 – IEC 61300-2-43:2014 © IEC 2014
The criteria for the screen test of the measurement connectors are given by:
–10 log P2/P8 + 14,7 ≥ L + α (dB) (A.4)
rs
c) The pigtail under test is screen tested using one of the pair reference connectors.
– Remove the reference connector 2a from reference connector 1a.
– Connect measurement connector 4a to the reference connector 1a, then measure the
power P3 (see  in Figure A.1).
The criteria for the screen test of the measurement connectors is given by:
–10 log P3/P8 + 14,7 ≥ L + α (dB) (A.5)
rs
The parameters β and α are determined by simulation so that the return loss of mating point
exceeds the specified return loss L with high probability when the screen tested connectors
rs
are randomly connected.
Figure A.2 shows the relation between β and α derived by the condition that the return loss at
the mating point exceeds a specified value L with a probability of 99 %. The white circles
rs
represent the simulation results for pigtails. The black circles represent those for cords. The
lines indicate first-order regression lines. The figure indicates that the return loss of randomly
concatenated cords exceeds L (in decibels) with a probability of 99 % under the condition of
rs
α ≥ 0,4β – 2,0. The parameters β and α shall be determined according to this condition.
α = 0,45β − 0,3
Cord
−2
Pigtail
α = 0,4β − 2,0
−4
0 2 4 6
−4 −2
β  (dB)
IEC  2027/14
Figure A.2 – Relationship between ß and α
Figure A.3 shows the cumulative probability of return loss before screen testing. Figure A.4
shows the cumulative probability of return loss when pigtails were screen tested under the
condition of Equation (A.5) using the reference cord selected in accordance with Equation
(A.1). The parameters L , β and α are set at 45 dB, 5 dB and 2 dB, respectively. For pigtails,
rs
the probability exceeds 99 % when the return loss L is greater than 45 dB.

rs
α  (dB)
0,1
35 40 45 50 55 60 65
Return loss  (dB)
IEC  2028/14
Figure A.3 – Cumulative probability of return loss before test
β = 5, α = 2
35 40 45 50 55 60 65
Return loss  (dB)
IEC  2029/14
Figure A.4 – Cumulative probability of return loss after test
It is also important for the screen testing of pigtails that the fibre surface condition of one of
the paired reference connectors is almost equal to that of the other reference connector.
Figure A.5 shows the relation of the difference of P4 and P5 and difference of α and α
...