IEC 60874-1:2011

IEC 60874-1 ®
Edition 6.0 2011-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Connectors
for optical fibres and cables –
Part 1: Generic specification
Dispositifs d’interconnexion et composants passifs à fibres optiques –
Connecteurs pour fibres et câbles optiques –
Partie 1: Spécification générique

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IEC 60874-1 ®
Edition 6.0 2011-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Connectors
for optical fibres and cables –
Part 1: Generic specification
Dispositifs d’interconnexion et composants passifs à fibres optiques –
Connecteurs pour fibres et câbles optiques –
Partie 1: Spécification générique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
S
CODE PRIX
ICS 33.180.20 ISBN 978-2-88912-776-4
– 2 – 60874-1 © IEC:2011
CONTENTS
FOREWORD . 4

1 Scope . 6

2 Normative references. 6

3 Terms and definitions . 7

4 Requirements . 10

4.1 General . 10

4.2 Classification . 10

4.2.1 General . 10
4.2.2 Type . 10
4.2.3 Arrangement . 11
4.2.4 Style . 11
4.2.5 Interface standard . 12
4.2.6 Variant . 12
4.2.7 Assessment level . 12
4.2.8 Normative reference extensions . 13
4.3 Documentation . 13
4.3.1 Symbols. 13
4.3.2 Specification system . 14
4.3.3 Drawings . 15
4.3.4 Performance . 15
4.3.5 Measurements . 16
4.3.6 Test reports . 16
4.3.7 Instructions for use . 16
4.4 Standardization system . 16
4.4.1 Interface standards . 16
4.4.2 Performance standards . 17
4.4.3 Optical interface standards . 17
4.4.4 Reliability documentation . 18
4.4.5 Interlinking . 18
4.5 Design and construction . 20
4.5.1 Materials . 20
4.5.2 Workmanship . 20
4.6 Quality . 20

4.7 Performance . 20
4.8 Identification and marking . 20
4.8.1 Variant identification number . 20
4.8.2 Component marking . 20
4.8.3 Package marking . 21
4.9 Packaging . 21
4.10 Storage conditions . 21
4.11 Safety . 21
Bibliography . 22

Figure 1 – Standardization structure . 19

60874-1 © IEC:2011 – 3 –
Table 1 – Example of a typical connector set classification . 11

Table 2 – Three-level specification structure . 14

Table 3 – Standards interlink matrix . 19

– 4 – 60874-1 © IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
FIBRE OPTIC INTERCONNECTING DEVICES

AND PASSIVE COMPONENTS –
CONNECTORS FOR OPTICAL FIBRES AND CABLES –

Part 1: Generic specification
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,
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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-
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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
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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6) All users should ensure that they have the latest edition of this publication.
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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 60874-1 has been prepared by subcommittee 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This sixth edition cancels and replaces the fifth edition published in 2006, and constitutes a
technical revision. The specific technical changes from the previous edition include removal of
quality assessment procedure, to add the definition of plug-socket configuration, to reconsider
a drawing showing the relationship between IEC 60874, IEC 61753, IEC 61754 series of
standards., and updating the normative references.

60874-1 © IEC:2011 – 5 –
The text of this standard is based on the following documents:

FDIS Report on voting
86B/3272/FDIS 86B/3304/RVD
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 of the IEC 60874 series, under the general title Fibre optic interconnecting
devices and passive components – Connectors for optical fibres and cables 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.
– 6 – 60874-1 © IEC:2011
FIBRE OPTIC INTERCONNECTING DEVICES

AND PASSIVE COMPONENTS –
CONNECTORS FOR OPTICAL FIBRES AND CABLES –

Part 1: Generic specification
1 Scope
This part of IEC 60874 applies to fibre optic connector sets and individual components (i.e.
adaptors, plugs, sockets) for all types, sizes and structures of fibres and cables. It includes:
– connector set requirements;
This part of IEC 60874 is divided into four clauses:
– Clauses 1 (Scope), 2 (Normative references) and 3 (Terms and definitions) contain general
information pertaining to this generic specification;
– Clause 4 (Requirements) contains all the requirements to be met by connectors covered by
this specification. This includes requirements for classification, the IEC specification system,
documentation, materials, workmanship, quality, performance, identification, and packaging.
NOTE 1 Clauses 1 to 4 are applicable generally and refer to all connector standards
NOTE 2 This part of IEC 60874 applies also to the connectors covered by the IEC 61753, IEC 61754, and
IEC 61755 series.
This standard does not cover test and measurement procedures, which are described in the
IEC 61300 series.
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 60027 (all parts), Letter symbols to be used in electrical technology
IEC 60050-731, International Electrotechnical Vocabulary – Chapter 731: Optical fibre

communication
IEC 60617, Graphical symbols for diagrams
IEC 60695-11-5, Fire hazard testing – Part 11-5: Test flames – Needle-flame test method –
Apparatus, confirmatory test arrangement and guidance
IEC 60825-1, Safety of laser products – Part 1: Equipment classification and requirements
IEC 61300 (all parts), Fibre optic interconnecting devices and passive components – Basic test
and measurement procedures
IEC 61753 (all parts), Performance standards

60874-1 © IEC:2011 – 7 –
IEC 61753-1: Fibre optic interconnecting devices and passive components – Part 1: General

and guidance for performance standards

IEC 61754 (all parts), Fibre optic connector interfaces

IEC 61755 (all parts), Fibre optic connector optical interfaces

IEC/TR 61930, Fibre optic graphical symbology

IEC/TR 61931, Fibre optic terminology

ISO 129, Technical drawings – Indication of dimensions and tolerances – Part 1: General
principles
ISO 286-1, Geometrical product specifications (GPS) – ISO code system for tolerances on
linear sizes – Part 1: Bases of tolerances, deviations and fits
ISO 1101, Geometrical product specifications (GPS) – Geometrical tolerancing – Tolerances of
form, orientation, location and run-out
ISO 8601, Data elements and interchange formats – Information interchange – Representation
of dates and times
3 Terms and definitions
For the purposes of this part of IEC 60874, the definitions contained in IEC 60050-731 and
IEC 61931, as well as the following definitions, apply.
3.1
adaptor
a component in which two or more ferrules are aligned
3.2
alignment pins
cylindrical rods used for alignment in some types of connectors
NOTE Typically these are used in pairs and inserted into specific guide holes in the two plugs (usually for
multifibre connectors) to provide the alignment.
3.3
APC connector
connector with angled convex end-face ferrule capable of making an angled physical contact
between the fibres
3.4
butting optical coupling
coupling in which the optical ports are in contact with each other
3.5
expanded beam optical coupling
coupling in which the optical ports use lens technology
3.6
ferrule
fibre holding component part of the plug, usually aligned in the sleeve of an adaptor. It confines
the end(s) of a single or of multiple optical fibres

– 8 – 60874-1 © IEC:2011
3.7
fully intermateable connector set

connector sets from different sources are considered fully intermateable when connector

components from one source will mate with complementary components from other sources

without mechanical damage and with optical properties maintained within specified limits

3.8
interchangeable connector set
connector sets are considered to be interchangeable when they share common installation

geometry and have the same functional performance

3.9
mating face dimension
dimension of the features which determine the mating fit between components of an optical
connector set
3.10
mechanically intermateable connector set
connector sets from different sources are considered mechanically intermateable when
connector components from one source will mate with complementary components from other
sources without mechanical damage but without regard to optical properties
3.11
mechanical reference plane (datum plane)
the plane of a plug or adaptor which is perpendicular to the fibre axis and is located on a
physical feature of the component. It is the datum plane from which all features of the
component are measured in the direction of the fibre axis
NOTE The mechanical reference planes of the plug and the adaptor should coincide when the two components are
properly mated. Accordingly, each should be located on the feature that fixes or establishes the relative position of
the two components when they are properly mated.
3.12
non-butting optical coupling
coupling in which the ports are not in contact with each other
3.13
optical datum target
theoretical datum point on a connector interface where the optical fibre core centre should be
positioned by the plug or by the adaptor receptacle
3.14
optical fibre connector
component normally attached to an optical cable or piece of apparatus, for the purpose of
providing frequent optical interconnection/disconnection of optical fibres or cables. This usually
consists of two plugs mated together in an adaptor
3.15
optical fibre connector set
complete assembly of components required to provide demountable coupling between two or
more optical fibre cables
3.16
optical fibre connector set kit
series of components necessary to make a complete connector set

60874-1 © IEC:2011 – 9 –
3.17
optical fibre patchcord or jumper

length of optical fibre or cable, permanently terminated at both ends with two plugs

3.18
optical fibre pigtail
length of optical fibre or cable, permanently terminated at one end with a plug

3.19
PC connector
connector with convex end-face ferrule capable of making a physical contact between the

fibres
3.20
plug
male-type part of a connector
3.21
plug-adaptor-plug configuration
configuration in which two plugs mate through an adaptor. The mechanical coupling takes
place between the plugs and the adaptor
3.22
plug-receptacle configuration
configuration in which a plug mates in a receptacle
3.23
plug-socket configuration
configuration in which a plug mates in a socket. The mechanical coupling takes place between
the plug and the socket
3.24
receptacle
structure for interfacing a plug with an active component. Typically it is formed by a semi-
adaptor and a structure containing and aligning the active component
3.25
reference connector component
tighter toleranced or selected connector component (e.g. plug, adaptor, etc.) which is used for
measuring purposes
NOTE Test and measurement methods may refer to this. The characteristics or the selection procedure are given
in the relevant specification.
3.26
sleeve
precision part of the adaptor used to mechanically align two ferrules
3.27
small form factor connector (SFF)
an optical fibre connector with a ferrule with an outside diameter of less than 2.0 mm or a
connector designed to accommodate two or more optical fibres with at least the same
mounting density as the RJ-45 connector
NOTE SFF connectors have a smaller cross-sectional area, about one-half that of traditional connectors.

– 10 – 60874-1 © IEC:2011
3.28
socket
the female part of a two part connector

4 Requirements
4.1 General
The requirements for connectors covered by this generic specification are specified in this

clause and in the detail specification.

4.2 Classification
4.2.1 General
Fibre optic connector sets are classified, either totally or in part, according to the following
categories:
– type;
– arrangement;
– style;
– interface standard;
– standardization system;
– variant;
– assessment level;
– normative reference extensions.
See Table 1 for an example of a complete connector set classification.
4.2.2 Type
Connector set types shall be defined by four elements: the type name, the configuration, the
coupling mechanism and the mating face dimensions.
Examples of type names:
– type SC;
– type LC.
Examples of configurations:
– plug-adaptor-plug configuration;
– plug-receptacle configuration.
Examples of coupling mechanisms:
– screw thread;
– bayonet;
– push-pull.
60874-1 © IEC:2011 – 11 –
Table 1 – Example of a typical connector set classification

Type – Name: type SC
– Configuration: plug-adaptor-plug

– Coupling: push -pull
– Mating face dimensions:
a
plug: see Figure 2
a
adaptor: see Figure 4
Arrangement – Kit
Style – Fibre retention: adhesive

– Cable retention: crimp
– Optical coupling: PC
– Alignment: resilient bushing
Variants – Twelve plug permutations of:
• fibre diameters
0,125 mm
• cable jacket diameters
2,4 mm
3,0 mm
• coupling styles:
push –pull plastic housing.
– Two adaptor variants:
• non-mountable (in-line)
• four-hole flange mount
a
Indicates figures in a hypothetical detail specification

4.2.3 Arrangement
The connector set arrangement shall define the delivered connector set form.
Examples of connector set arrangements:
– kit arrangement for plug and adaptor;
– pigtail arrangement for plug;
– patch-cord arrangement for plugs.
4.2.4 Style
The connector set style shall be defined by four elements: the fibre retention technology, the
cable retention technology, the optical coupling technology and the alignment technology.

Examples of fibre retention technologies:
– adhesive fibre retention;
– crimp fibre retention.
Examples of cable retention technologies:
– adhesive cable retention;
– crimp cable retention.
Examples of optical coupling technologies:
– non-butting;
– physical contact (PC)
– angled physical contact (APC);

– 12 – 60874-1 © IEC:2011
– expanded beam.
Examples of alignment technologies:

– clearance fit alignment;
– resilient bushing alignment;

– resilient tip alignment;
– spherical alignment;
– solid bore alignment sleeve;

– resilient alignment sleeve;
– V-groove alignment;
– guide pin alignment.
4.2.5 Interface standard
The connector interface standard defines the dimensions and the physical features essential
for mating and unmating a fibre optic connector with other connectors or components
conforming to the same standard interface (see 4.4.1).
4.2.6 Variant
The connector set variant defines the variety of structurally similar components.
Examples of feature variables which create variants:
– fibre type (category, core and cladding diameter);
– cable type and size;
– mounting scheme;
– coupling nut design (hexagonal, knurled, etc.).
4.2.7 Assessment level
Assessment level defines the inspection levels and the acceptable quality level (AQL) of groups
A and B, and the periodicity of inspection of groups C and D. Detail specifications shall specify
one or more assessment levels, each of which shall be designated by a capital letter.
The following are preferred levels.
• Assessment level A
– group A inspection: inspection level 11, AQL = 4 %
– group B inspection: inspection level 11, AQL = 4 %
– group C inspection: 24-month periods
– group D inspection: 48-month periods
• Assessment level B
– group A inspection: inspection level 11, AQL = 1 %
– group B inspection: inspection level 11, AQL = 1 %
– group C inspection: 18-month periods
– group D inspection: 36-month periods
• Assessment level C
– group A inspection: inspection level 11, AQL = 0,4 %

60874-1 © IEC:2011 – 13 –
– group B inspection: inspection level 11, AQL = 0,4 %

– group C inspection: 12-month periods

– group D inspection: 24-month periods

4.2.8 Normative reference extensions

Normative reference extensions are used to identify integration of independent standards

specifications or other reference documents into blank detail specifications.

Unless a specified exception is noted, additional requirements imposed by an extension are

mandatory. Usage is primarily intended to merge associated components to form hybrid
devices, or can involve integrated functional application requirements that are dependent on
technical expertise other than fibre optics.
Published reference documents produced by ITU consistent with the scope statements of the
relevant IEC specification series may be used as extensions. Published documents produced
by other regional standardization bodies such as TIA, ETSI, JIS, etc, may be referenced in an
informative annex attached to the generic specification.
Some optical fibre splice configurations require special qualification provisions which shall not
be imposed universally. These accommodate individual component design configurations,
specialised field tooling, or specific application processes and involve requirements necessary
to assure repeatable performance or adequate safety. They also provide additional guidance
for complete product specification. Such extensions are mandatory whenever used in the
preparation, assembly or installation of an optical fibre splice, either for field application usage
or preparation of qualification test specimens. The relevant specification shall clarify all
stipulations. However, design and style dependent extensions shall not be imposed universally.
In the event of conflicting requirements, precedence shall be given, in descending order, as
follows: generic over mandatory extension, over blank detail, over detail, over application
specific extension.
Examples of optical connector extensions include:
– using IEC 61754-2 and IEC 61754-4 to partially define a future specification within the
IEC 60874 series for a duplex type “SC/BFOC/2,5” hybrid connector adaptor;
– using IEC 61754-13 to partially define a future specification within the IEC 60874 series for
an integrated type “FC” preset attenuated optical connector;
– using IEC 61754-2 to partially define a specification within the IEC 60874 series for a
duplex “BFOC/2,5” receptacle incorporating integral mechanical splices.

Other examples of requirements in normative extensions:
– some commercial or residential building applications may require direct reference to
specific safety codes and regulations, or incorporate other specific material flammability or
toxicity requirements for specialised locations;
– specialised field tooling may require an extension to implement specific ocular safety,
electrical shock, or burn hazard avoidance requirements, or require isolation procedures to
prevent potential ignition of combustible gases.
4.3 Documentation
4.3.1 Symbols
Graphical and letter symbols shall, whenever possible, be taken from IEC 60027, IEC 60617
and IEC 61930.
– 14 – 60874-1 © IEC:2011
4.3.2 Specification system
4.3.2.1 General
This specification is part of a three-level IEC specification system. Subsidiary specifications
shall consist of blank detail specifications and detail specifications. This system is shown in
Table 2.
Table 2 – Three-level specification structure

Specification level Examples of information to be included Applicable to

– Assessment system rules
Two or more component families or
– Inspection rules
subfamilies
– Optical measurement methods
– Environmental test methods
– Sampling plans
– Identification rule
Basic – Marking standards
– Interface dimensions
– Dimensional standards
– Terminology
– Symbol standards
– Preferred number series
– SI units
– Specific terminology
– Specific symbols
– Specific units
– Preferred values
Generic – Marking Component family
– Quality assessment procedures
– Selection test
– Qualification approval procedures
– Capability approval procedure
– Quality conformation test schedule
Groups of types having a common test
a
Blank detail – Inspection requirements
schedule
– Information common to a number of types
– Individual values
Detail – Specific information Individual type
– Completed quality conformance test schedules

a
Blank detail specifications do not, by themselves, constitute a specification level. They are associated to the
generic specification
4.3.2.2 Blank detail specifications
A blank detail specification shall contain:
– the minimum mandatory test schedules and performance requirements;
– one or more assessment levels;
– the preferred format for stating the required information in the detail specification;
– in the case of hybrid components, including connectors, addition of appropriate entry fields
to show the reference normative document, document title and issue date.

60874-1 © IEC:2011 – 15 –
4.3.2.3 Detail specifications
Detail specifications shall specify the following as a minimum:

– type name (see 4.2.2);
– arrangement (see 4.2.3);
– connector set style (see 4.2.4);

– interface standards(4.2.5);
– variants (see 4.2.6);
– assessment level (see 4.2.7);

– qualification procedure method;
– part identification number for each variant (see 4.8.1);
– drawings, dimensions and performance criteria necessary to produce all required reference
components (see 4.3.3);
– drawings and dimensions necessary to produce all required gauges (see 4.3.3);
– quality assessment test schedules;
– performance requirements (see 4.7).
4.3.3 Drawings
4.3.3.1 General
The drawings and dimensions given in documents covered by this specification shall not
restrict the details of construction nor shall they be used as manufacturing drawings.
4.3.3.2 Projection system
Either first angle or third angle projection shall be used for the drawings in documents covered
by this specification. All drawings within a document shall use the same projection system and
the drawings shall state which system is used.
4.3.3.3 Dimensional system
All dimensions shall be given in accordance with ISO 129, ISO 286-1 and ISO 1101.
The metric system shall be used in all specifications.
Dimensions shall not contain more than five significant digits.

When units are converted, a note shall be added in each relevant specification and the
conversion between systems of units shall use a factor of 25.4 mm to 1 inch.
4.3.3.4 lntermateability
The requirements for mechanical intermateability are defined in the interface standards series
IEC 61754.
The requirements for optical intermateability are defined in the optical interface standards
series IEC 61755.
4.3.4 Performance
The performance requirements for fibre optic connectors are defined in the performance
standard series IEC 61753 (all parts).

– 16 – 60874-1 © IEC:2011
4.3.5 Measurements
4.3.5.1 Measurement method
The size measurement method to be used shall be specified in the specification for dimensions
which are specified within a total tolerance zone of 0,01 mm (0,000 4 in) or less.

4.3.5.2 Reference components
Reference components, if required, shall be specified in the relevant specification.

4.3.5.3 Gauges
Gauges, if required, shall be specified in the relevant specification.
4.3.6 Test reports
Test reports shall be prepared for each test conducted. The reports shall be included in the
qualification approval report and in the periodic inspection report.
Test reports shall contain the following information as a minimum:
– title of test and date;
– specimen description, including the type of fibre. The description shall also include the
variant identification number (see 4.8.1);
– test equipment used and date of latest calibration;
– all applicable test details;
– all measurement values and observations;
– sufficiently detailed documentation to provide traceable information for failure analysis.
4.3.7 Instructions for use
Instructions for use shall be given by the manufacturer and shall consist of:
– assembly and termination instructions;
– cleaning method;
– additional information as necessary.
4.4 Standardization system
4.4.1 Interface standards
Interface standards provide both manufacturer and user with all the information required to
manufacture or use the product in conformity with the physical features foreseen by that
standard interface. Interface standards fully define and dimension the features essential for the
mating and unmating of optical fibre connectors and other components. They also serve to
position the optical datum target, where defined, relative to other reference data.
Interface standards ensure that connectors and adaptors complying with the standard fit
together. The standards may also contain tolerance grades for ferrules and alignment devices.
Tolerance grades are used to provide different levels of alignment precision.
The interface dimensions may also be used to design other components that will mate with the
connectors. For example, an active device mount can be designed using the adaptor interface
dimensions. The use of these dimensions combined with those of a standard plug provides the
designer with assurance that standard plugs will fit into the optical device mount. They also
provide the location of the plug optical datum target.

60874-1 © IEC:2011 – 17 –
Standardised interface dimensions do not, by themselves, guarantee optical performance. They

guarantee connector mating at a specified fit. Optical performance is ensured by compliance

with the requirements of the optical interface standard series. Products from the same or

different manufacturing specifications using the same standard interface will always fit together.

A guarantee of performance can be given by any individual manufacturer only for products

delivered according to the same manufacturing specification. However, it can be reasonably
expected that a certain level of performance will be obtained by mating products from different
manufacturing specifications, although this level of performance cannot be expected to be any

better than that of the lowest specified performance.

4.4.2 Performance standards
Performance standards contain a series of test and measurements sets (which, depending on
the requirements of the standard, may or may not be grouped into a specified schedule) with
clearly defined conditions, severities and pass/fail criteria. The tests are intended to be run on
a “one-off” basis to prove the ability of a given product to satisfy the “performance standards”
requirement. Each performance standard has a different set of tests, and/or severities (and/or
groupings) and represents the requirements of a market sector, user group or system location.
A product that has been shown to meet all the requirements of a performance standard can be
declared as complying with that standard, but should then be controlled by a quality assurance/
quality conformance programme.
A key point of the performance standards is the selection of tests and severities from the tests
and measurements standards, for application in conjunction with interface standards on inter-
product compatibility (this particularly relates to attenuation and return loss). The certain
conformance of each individual product to this standard will be ensured.
4.4.3 Optical interface standards
An optical interface standard is a multi-part collection of the physical and mechanical require-
ments necessary in order to comply with the optical functionality specifications for a defined
interface between two optical fibres. It consists of those essential features that are functionally
critical to the optical attenuation and return loss performance of an optical interface in the
mated condition. The standard defines the location of the fibre core in relation to the datum
target and the following key parameters: lateral offset, end face separation, end face angle,
end face high index layer condition. It also defines standardised test methods where
appropriate.
Each interface contains the essential information to ensure that products conforming to the
standard will work together repeatedly to a known level of optical performance without the need
for compatibility testing or cross checking.

The two basic performance parameters that characterise the optical interface are attenuation
and return loss. Each parameter places different physical constraints on the optical interface.
Environmental conditions also affect the performance of the optical interface and it may require
definition of physical and mechanical requirements to ensure that the performance specified is
maintained over the environmental extremes defined in a particular performance standard.
Manufacturing materials and processes also affect the optical interface and therefore the
standard has been designed to allow manufacturers to demonstrate compliance with the
standard while still permitting the maximum of manufacturing differentiation. The relationship
between and suitability of materials specified in Part 3 documents of IEC 61755 series, for
different performance categories as specified in IEC 61753-1 shall be defined, e.g. zirconia
ferrule material can be applied in all environmental categories, while the polymer material
specified for some rectangular ferrules may only be applicable for category C.

– 18 – 60874-1 © IEC:2011
Optical interface standards define sets of prescribed conditions, which must be maintained in

order to satisfy the requirements for the attenuation and return loss performance in a randomly

mated pair of fibres of the same type.

4.4.4 Reliability documentation

Reliability documentation is intended to ensure that a component can meet performance

specifications under stated conditions for a stated time period.

For each type of component, the following should be identified (and appear in the reliability

documentation):
– failure modes (observable general mechanical or optical effects of failure);
– failure mechanisms (general causes of failure, common to several components);
– failure effects (detailed causes of failure, specific to the component).
These are all related to environmental and material aspects.
Initially, just after the component manufacturing, there is an “infant mortality phase” during
which many components would fail if they were deployed in the field. To avoid early field failure,
all components may be subjected to a screening process in the factory, involving environmental
stresses that may be mechanical, thermal, or humidity-related. This induces known failure
mechanisms in a controlled environmental situation to occur earlier than would normally be
verified among an unscreened populatio
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