IEC 60793-2-10:2017

IEC 60793-2-10 ®
Edition 6.0 2017-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 2-10: Product specifications – Sectional specification for category
A1 multimode fibres
Fibres optiques –
Partie 2-10: Spécifications de produits – Spécification intermédiaire pour les
fibres multimodales de catégorie A1

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IEC 60793-2-10 ®
Edition 6.0 2017-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibres –
Part 2-10: Product specifications – Sectional specification for category

A1 multimode fibres
Fibres optiques –
Partie 2-10: Spécifications de produits – Spécification intermédiaire pour les

fibres multimodales de catégorie A1

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-4627-6

– 2 – IEC 60793-2-10:2017 © IEC 2017

CONTENTS
FOREWORD . 5

1 Scope . 7

2 Normative references . 7

3 Terms, definitions . 8

4 Abbreviated terms . 8

5 Specifications . 9

5.1 General . 9
5.2 Dimensional requirements . 9
5.3 Mechanical requirements . 10
5.4 Transmission requirements . 11
5.5 Environmental requirements . 13
5.5.1 General . 13
5.5.2 Mechanical environmental requirements (common to all fibres in
category A1) . 14
5.5.3 Transmission environmental requirements . 14
Annex A (normative) Specifications for sub-category A1a multimode fibres . 16
A.1 General . 16
A.2 Dimensional requirements . 16
A.3 Mechanical requirements . 17
A.4 Transmission requirements . 17
A.5 Environmental requirements . 18
Annex B (normative) Specifications for sub-category A1b multimode fibres . 19
B.1 General . 19
B.2 Dimensional requirements . 19
B.3 Mechanical requirements . 19
B.4 Transmission requirements . 19
B.5 Environmental requirements . 20
Annex C (normative) Specifications for sub-category A1d multimode fibres . 21
C.1 General . 21
C.2 Dimensional requirements . 21
C.3 Mechanical requirements . 21
C.4 Transmission requirements . 21
C.5 Environmental requirements . 22
Annex D (normative) Fibre differential mode delay (DMD), calculated effective modal
bandwidth (EMB ) and calculated overfilled modal bandwidth (OMB )
c c
requirements . 23
D.1 A1a.2 fibre DMD requirements . 23
D.1.1 General . 23
D.1.2 DMD templates . 23
D.1.3 DMD interval masks . 24
D.2 A1a.2 fibre EMB requirements . 25
c
D.2.1 General . 25
D.2.2 Calculated effective bandwidth . 25
D.3 A1a.3 DMD requirements . 27
D.3.1 General . 27

D.3.2 DMD templates . 27

D.3.3 DMD interval masks . 28

D.4 A1a.3 fibre EMB requirements . 28

c
D.4.1 General . 28

D.4.2 Calculated effective bandwidth . 28

D.5 A1a.4 fibre modal bandwidth requirements. 28

D.5.1 General . 28

D.5.2 Calculated effective modal bandwidth . 28

D.5.3 Calculated overfilled modal bandwidth . 29

Annex E (informative) System, modal bandwidth, and transmitter considerations . 30
E.1 Background . 30
E.2 System considerations . 30
E.2.1 A1a.2 and A1a.3 fibres . 30
E.2.2 A1a.4 fibre . 30
E.3 Effective modal bandwidth (EMB). 31
E.4 Transmitter encircled flux (EF) and centre wavelength requirements . 32
E.4.1 Encircled flux . 32
E.4.2 Centre wavelength for A1a.2 and A1a.3 fibres . 33
E.4.3 Centre wavelength for A1a.4 fibre . 33
Annex F (informative) Bandwidth nomenclature explanation. 34
Annex G (informative) Preliminary indications for items needing further study . 35
G.1 Effective modal bandwidth (EMB) at 1 300 nm . 35
G.2 Scaling of EMB with DMD . 35
Annex H (informative) Applications and cabling categories supported by A1 fibres . 37
H.1 Standardised applications . 37
H.2 Cross reference of cabled optical fibre performance categories in
ISO/IEC 11801-1 to fibres of this document . 37
Annex I (informative) 1-Gigabit, 10-Gigabit, 25-Gigabit, 40-Gigabit and 100-Gigabit
Ethernet applications . 39
Bibliography . 44

Figure 1 – Relation between bandwidths at 850 nm and 1 300 nm . 13
Figure D.1 – DMD template requirements . 24
Figure E.1 – Estimated minimum wide band EMB versus wavelength . 32

Figure E.2 – Approximate position of DMD weightings relative to the EF boundaries of
Equations (E.6) and (E.7) . 33

Table 1 – Dimensional attributes and measurement methods . 9
Table 2 – Dimensional requirements common to category A1 fibres . 10
Table 3 – Additional dimensional attributes required in sub-category specifications . 10
Table 4 – Mechanical attributes and measurement methods . 10
Table 5 – Mechanical requirements common to category A1 fibres . 11
Table 6 – Transmission attributes and measurement methods . 11
Table 7 – Additional transmission attributes required in sub-category specifications . 12
Table 8 – Environmental exposure tests . 13
Table 9 – Attributes measured for environmental tests . 13
Table 10 – Strip force for environmental tests . 14

– 4 – IEC 60793-2-10:2017 © IEC 2017

Table 11 – Tensile strength for environmental tests . 14

Table 12 – Stress corrosion susceptibility for environmental tests . 14

Table 13 – Change in attenuation for environmental tests . 15

Table A.1 – Dimensional requirements specific to A1a fibres . 16

Table A.2 – Mechanical requirements specific to A1a fibres . 17

Table A.3 – Transmission requirements specific to A1a fibres . 18

Table B.1 – Dimensional requirements specific to A1b fibres . 19

Table B.2 – Mechanical requirements specific to A1b fibres . 19

Table B.3 – Transmission requirements specific to A1b fibres . 20
Table C.1 – Dimensional requirements specific to A1d fibres . 21
Table C.2 – Mechanical requirements specific to A1d fibres . 21
Table C.3 – Transmission requirements specific to A1d fibres . 22
Table D.1 – DMD templates for A1a.2 fibres . 23
Table D.2 – DMD interval masks for A1a.2 fibres . 25
Table D.3 – DMD weightings . 26
Table D.4 – DMD templates for A1a.3 fibres . 28
Table D.5 – DMD interval masks for A1a.3 fibres . 28
Table D.6 – DMD weighting for OMB . 29
c
Table F.1 – Bandwidth nomenclature explanation . 34
Table H.1 – Some standardised applications supported by A1a fibres and in some
cases A1b fibres . 37
Table H.2 – Cross reference between ISO/IEC 11801-1 and this document . 38
Table I.1 – Summary of 1 Gb/s, 10 Gb/s, 25 Gb/s, 40 Gb/s and 100 Gb/s Ethernet
requirements and capabilities . 40

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
OPTICAL FIBRES –
Part 2-10: Product specifications –

Sectional specification for category A1 multimode fibres

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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International Standard IEC 60793-2-10 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This sixth edition cancels and replaces the fifth edition published in 2015. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) addition of model A1a.4 fibre which supports single wavelength or multi-wavelength
transmission systems in the vicinity of 850 nm to 950 nm.
The text of this standard is based on the following documents:
CDV Report on voting
86A/1771/CDV 86A/1794/RVC
– 6 – IEC 60793-2-10:2017 © IEC 2017

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 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 document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be

• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
OPTICAL FIBRES –
Part 2-10: Product specifications –

Sectional specification for category A1 multimode fibres

1 Scope
This part of IEC 60793 is applicable to optical fibre sub-categories A1a, A1b, and A1d. These

fibres are used or can be incorporated in information transmission equipment and optical fibre
cables.
Sub-category A1a applies to 50/125 µm graded index fibre. Four bandwidth grades are
defined as models A1a.1, A1a.2, A1a.3 and A1a.4. Each of these bandwidth grades is defined
for two levels of macrobend loss performance that are distinguished by "a" or "b" suffix. Those
models with suffix "a" are specified to meet traditional macrobend loss performance levels.
Those models with suffix "b" are specified to meet enhanced macrobend loss (i.e. lower loss)
performance levels. Model A1a.4 supports single wavelength or multi-wavelength
transmission systems in the vicinity of 850 nm to 950 nm.
Sub-category A1b applies to 62,5/125 µm graded index fibre and sub-category A1d applies to
100/140 µm graded index fibre.
Other applications include, but are not restricted to, the following: short reach, high bit-rate
systems in telephony, distribution and local networks carrying data, voice and/or video
services; on-premises intra-building and inter-building fibre installations including data
centres, local area networks (LANs), storage area networks (SANs), private branch
exchanges (PBXs), video, various multiplexing uses, outside telephone cable plant use, and
miscellaneous related uses.
Three types of requirements apply to these fibres:
• general requirements, as defined in IEC 60793-2;
• specific requirements common to the category A1 multimode fibres covered in this
document and which are given in Clause 5;
• particular requirements applicable to individual fibre sub-categories and models, or
specific applications, which are defined in the normative specification annexes.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60793-1-20, Optical fibres – Part 1-20: Measurement methods and test procedures –
Fibre geometry
IEC 60793-1-21, Optical fibres – Part 1-21: Measurement methods and test procedures –
Coating geometry
IEC 60793-1-22, Optical fibres – Part 1-22: Measurement methods and test procedures –
Length measurement
IEC 60793-1-30, Optical fibres – Part 1-30: Measurement methods and test procedures –
Fibre proof test
IEC 60793-1-31, Optical fibres – Part 1-31: Measurement methods and test procedures –
Tensile strength
– 8 – IEC 60793-2-10:2017 © IEC 2017

IEC 60793-1-32, Optical fibres – Part 1-32: Measurement methods and test procedures –

Coating strippability
IEC 60793-1-33, Optical fibres – Part 1-33: Measurement methods and test procedures –

Stress corrosion susceptibility

IEC 60793-1-34, Optical fibres – Part 1-34: Measurement methods and test procedures –

Fibre curl
IEC 60793-1-40, Optical fibres – Part 1-40: Measurement methods and test procedures –

Attenuation
IEC 60793-1-41, Optical fibres – Part 1-41: Measurement methods and test procedures –
Bandwidth
IEC 60793-1-42, Optical fibres – Part 1-42: Measurement methods and test procedures –
Chromatic dispersion
IEC 60793-1-43, Optical fibres – Part 1-43: Measurement methods and test procedures –
Numerical aperture measurement
IEC 60793-1-46, Optical fibres – Part 1-46: Measurement methods and test procedures –
Monitoring of changes in optical transmittance
IEC 60793-1-47, Optical fibres – Part 1-47: Measurement methods and test procedures –
Macrobending loss
IEC 60793-1-49, Optical fibres – Part 1-49: Measurement methods and test procedures –
Differential mode delay
IEC 60793-1-50, Optical fibres – Part 1-50: Measurement methods and test procedures –
Damp heat (steady state) tests
IEC 60793-1-51, Optical fibres – Part 1-51: Measurement methods and test procedures –Dry
heat (steady state) tests
IEC 60793-1-52, Optical fibres – Part 1-52: Measurement methods and test procedures –
Change of temperature tests
IEC 60793-1-53, Optical fibres – Part 1-53: Measurement methods and test procedures –
Water immersion tests
IEC 60793-2:2015, Optical fibres – Part 2: Product specifications – General
IEC 61280-4-1:2009, Fibre-optic communication subsystem test procedures – Part 4-1:
Installed cable plant – Multimode attenuation measurement

3 Terms, definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Abbreviated terms
CPR coupled power ratio
DMD differential mode delay
EF encircled flux
EMB effective modal bandwidth
EMB calculated effective modal bandwidth

c
LAN local area network
MMF multimode fibre
NA numerical aperture
OFL overfilled launch
OMB overfilled launch modal bandwidth calculated from differential mode delay (also
c
known as OFL )
c
PBX private branch exchange
PMD physical medium dependent
ROFL radial overfilled launch
SAN storage area network
5 Specifications
5.1 General
The fibre consists of a glass core with a graded index profile and a glass cladding in
accordance with IEC 60793-2:2015, 5.1.
The term "glass" usually refers to material consisting of non-metallic oxides.
5.2 Dimensional requirements
Dimensional attributes and measurement methods are given in Table 1.
Requirements common to all fibres in category A1 are indicated in Table 2.
Table 3 lists additional attributes that shall be specified by each sub-category specification.
Table 1 – Dimensional attributes and measurement methods
Attributes Measurement methods
Cladding diameter IEC 60793-1-20
a, b
IEC 60793-1-20
Core diameter
Cladding non-circularity IEC 60793-1-20
Core non-circularity IEC 60793-1-20
Core-cladding concentricity error IEC 60793-1-20
Primary coating diameter IEC 60793-1-21

Primary coating non-circularity IEC 60793-1-21
Primary coating-cladding concentricity error IEC 60793-1-21
Fibre length IEC 60793-1-22
a
Core diameter is specified at 850 nm ± 10 nm with a test specimen length of 2,0 m ± 0,2 m and a threshold
value, k , of 0,025 for A1 fibres except A1a.1b/2b/3b/4b fibres.
CORE
b
Core diameter is specified at 850 nm ± 10 nm with a test specimen length of 100 m ± 5 % and a threshold
value, k , of 0,025 for A1a.1b/2b/3b/4b fibres.
CORE
– 10 – IEC 60793-2-10:2017 © IEC 2017

Table 2 – Dimensional requirements common to category A1 fibres

Attributes Unit Limits
Core non-circularity %
≤ 6
a
µm 245 ± 10
Primary coating diameter – uncoloured

a
µm 250 ± 15
Primary coating diameter – coloured

Primary coating-cladding concentricity error
µm ≤ 12,5
b
Fibre length km
a
The limits on primary coating diameter are most commonly used in telecommunications cables. There are

other applications, which use other primary coating diameters, several of which are listed below.
Alternative nominal primary coating diameters and tolerance (µm):
400 ± 40
500 ± 50
700 ± 100
900 ± 100
b
Length requirements vary and should be agreed between supplier and customer.

Table 3 – Additional dimensional attributes required in sub-category specifications
Attributes
Cladding diameter
Cladding non-circularity
Core diameter
Core-cladding concentricity error

5.3 Mechanical requirements
Mechanical attributes and measurement methods are given in Table 4.
Requirements common to all fibres in category A1 are in Table 5.
Table 4 – Mechanical attributes and measurement methods
Attributes Test methods
Proof test IEC 60793-1-30
Tensile strength IEC 60793-1-31
Primary coating strippability IEC 60793-1-32

Stress corrosion susceptibility IEC 60793-1-33
Fibre curl IEC 60793-1-34
Table 5 – Mechanical requirements common to category A1 fibres

Attributes Unit Limits
a
Proof stress level GPa
≥ 0,69
b
N
1,0 ≤ F ≤ 5,0
Average strip force
avg
b
N
1,0 ≤ F ≤ 8,9
Peak strip force
peak
Tensile strength (median) for 0,5 m specimen length GPa
≥ 3,8
Stress corrosion susceptibility constant n ≥ 18
d
a
The proof test value of 0,69 GPa equals about 1 % strain or about 8,8 N force, for A1a and A1b fibres. For

the relation between these different units, see IEC TR 62048.
b
Either average strip force or peak strip force, which are defined in the test procedure, may be specified by
agreement between supplier and customer.

5.4 Transmission requirements
Transmission attributes and measurement methods are given in Table 6.
Table 7 lists additional attributes that shall be specified by each sub-category specification.
Table 6 – Transmission attributes and measurement methods
Attributes Measurement methods
Attenuation coefficient IEC 60793-1-40
a,b
IEC 60793-1-41
Modal bandwidth
c,d
IEC 60793-1-43
Numerical aperture
Chromatic dispersion IEC 60793-1-42
Change of optical transmission IEC 60793-1-46
Macrobending loss IEC 60793-1-47
e
IEC 60793-1-49
Differential mode delay
a
For modal bandwidth, either overfilled launch (OFL) or overfilled launch modal bandwidth calculated from
differential mode delay (OMB ) can be used. OMB is the reference test method for A1a.1/2/3 fibres at
c c
850 nm and is the required method for A1a.4 fibres at 850 nm and 953 nm.
b
850 nm modal bandwidth is specified with a test specimen length of 1 000 m ± 5 % for A1a.2/3/4 fibres. For
A1a.2 fibres, the 850 nm modal bandwidth is measured at 850 nm ± 10 nm. For A1a.3 and A1a.4 fibres, the
850 nm modal bandwidth is measured at 850 nm ± 2 nm. For A1a.4 fibre, the modal bandwidth is also
measured at 953 nm ± 6 nm.
c
Numerical aperture is specified at 850 nm ± 10 nm with a test specimen length of 2 m ± 0,2 m and a
threshold value, k , of 0,05 for A1 fibres except A1a.1b/2b/3b/4b fibres.
NA
d
Numerical aperture is specified at 850 nm ± 10 nm with a test specimen length of 100 m ± 5 % and a
threshold value, k of 0,05 for A1a.1b/2b/3b/4b fibres.

N,
e
Differential mode delay is specified with a test specimen length of 1 000 m ± 5 % for A1a.2/3/4 fibres. For
A1a.2 fibres, the DMD is measured at 850 nm ± 10 nm. For A1a.3 and A1a.4 fibres, the DMD is measured at
850 nm ± 2 nm. For A1a.4 fibre, the DMD is also measured at 953 nm ± 6 nm.

Specification compliance of chromatic dispersion can be assured by compliance to the
numerical aperture (NA) specification for A1 fibre.

– 12 – IEC 60793-2-10:2017 © IEC 2017

Table 7 – Additional transmission attributes

required in sub-category specifications

Attributes
Attenuation coefficient
Modal bandwidth
Chromatic dispersion
Numerical aperture
Macrobending loss
For attenuation coefficient and modal bandwidth, the sub-category specifications may contain
ranges of specifiable values instead of fixed limits. In this case, the actual values of the
maximum attenuation coefficient and minimum modal bandwidth, at both 850 nm and
1 300 nm (or just at one of these wavelengths) are to be agreed between supplier and
customer. For commercial purposes, the modal bandwidth is linearly normalized to 1 km.
For guidance purposes, Table H.1 shows a number of standardised applications supported by
A1 fibres, and Table H.2 provides a cross reference between the cabled optical fibre
categories of ISO/IEC 11801-1 and fibre sub-categories A1a and A1b of this document.
The indicated maximum attenuation values apply to uncabled optical fibres; for the maximum
cabled attenuation values, reference is made to IEC 60794-1-1, which can be used in
conjunction with this document.
Remarks on the specification of modal bandwidth:
Care should be taken in writing dual wavelength bandwidth specifications. It is understood
that for category A1 fibres, the bandwidth at 850 nm may be related to the bandwidth at
1 300 nm in a way shown in Figure 1, depending on the refractive index parameter, g, (see
IEC 60793-2:2015, 5.1). See [26] , page 50, and [27], page 255, for similar figures. The
shaded region under the curve of Figure 1 can be defined as the dual window area. In this
area, regions X, Y, and Z are examples of where a fibre manufacturer may choose to optimise
the process. That is, centre the production bandwidth peak at 850 nm, 1 300 nm, or between
these two wavelengths.
Due to this optimisation of the manufacturing process, there will be combinations of bandwidth
that are not possible (i.e., outside the shaded region).

____________
Under preparation. Stage at the time of publication: ISO/IEC RFDIS 11801-1:2017.
Numbers in square brackets refer to the Bibliography.

X
Y
Z
Normalised bandwidth at 1 300 nm (MHz⋅km)
IEC
Figure 1 – Relation between bandwidths at 850 nm and 1 300 nm
5.5 Environmental requirements
5.5.1 General
Environmental exposure tests and measurement methods are documented in two forms:
• relevant environmental attributes and test procedures are given in Table 8;
• measurements of a particular mechanical or transmission attribute that may change on the
application of the environment are listed in Table 9.
Table 8 – Environmental exposure tests
Environmental exposure Test
Damp heat IEC 60793-1-50
Dry heat IEC 60793-1-51
Change of temperature IEC 60793-1-52
Water immersion IEC 60793-1-53

Table 9 – Attributes measured for environmental tests
Attribute Measurement method
Change in optical transmission IEC 60793-1-46
Attenuation IEC 60793-1-40
Strip force IEC 60793-1-32
Tensile strength IEC 60793-1-31
Stress corrosion susceptibility IEC 60793-1-33

These tests are normally conducted periodically as type-tests for a fibre and coating design.
Unless otherwise indicated, the recovery period allowed between the completion of the
environmental exposure and performing the attribute measurements shall be as stated in the
particular environmental test method.
Normalised bandwidth at 850 nm (MHz⋅km)

– 14 – IEC 60793-2-10:2017 © IEC 2017

5.5.2 Mechanical environmental requirements (common to all fibres in category A1)

5.5.2.1 General
These tests are, in practice, the most severe requirements amongst the environments defined

in Table 8.
Tables 10, 11, and 12 give the prescriptions for strip force, tensile strength and stress

corrosion susceptibility respectively.

5.5.2.2 Strip force
The following attributes shall be verified following removal of the fibre from the particular

environment.
Table 10 – Strip force for environmental tests
Environment Average strip force Peak strip force
N N
Damp heat
1,0 ≤ F ≤ 5,0 1,0 ≤ F ≤ 8,9
avg peak
Water immersion
1,0 ≤ F ≤ 5,0 1,0 ≤ F ≤ 8,9
avg peak
5.5.2.3 Tensile strength
The following attribute shall be verified following removal of the fibre from the environment.
Table 11 – Tensile strength for environmental tests
Environment Median tensile strength 15th percentile tensile strength
specimen length: 0,5 m specimen length: 0,5 m
GPa GPa
Damp heat
≥ 3,03 ≥ 2,76
NOTE These requirements do not apply to hermetically coated fibre.

5.5.2.4 Stress corrosion susceptibility
The following attribute shall be verified following removal of the fibre from the environment.
Table 12 – Stress corrosion susceptibility for environmental tests
Environment Stress corrosion susceptibility constant, n
d
Damp heat ≥ 18
NOTE This requirement does not apply to hermetically coated fibre.

5.5.3 Transmission environmental requirements
Change in attenuation from the initial value shall be less than the values in Table 13.
Attenuation shall be measured periodically during the entire exposure to each environment
and after removal.
Table 13 – Change in attenuation for environmental tests

Environment Wavelength Attenuation increase

nm dB/km
Damp heat 850 ≤ 0,20
1 300
≤ 0,20
Dry heat 850
≤ 0,20
1 300 ≤ 0,20
Change of temperature 850 ≤ 0,20

1 300
≤ 0,20
Water immersion 850 ≤ 0,20
1 300 ≤ 0,20
– 16 – IEC 60793-2-10:2017 © IEC 2017

Annex A
(normative)
Specifications for sub-category A1a multimode fibres

A.1 General
Annex A contains particular requirements applicable to A1a fibres. Common requirements,

repeated here for ease of reference from the sectional specification, are noted by a clause

entry in the "Reference" column. The "Reference" column also refers to other annexes

containing relevant information on the attribute. Relevant notes from the sectional

SS
" "
specification are not repeated but indicated with a superscript .
Sub-category A1a is a 50/125 µm graded index fibre. Four bandwidth grades are defined as
models A1a.1, A1a.2, A1a.3 and A1a.4. All are specified using overfilled bandwidth metrics,
while models A1a.2, A1a.3 and A1a.4 also apply differential mode delay measurements to
deliver laser-optimised performance near 850 nm. Model A1a.4 also specifies both overfilled
and differential mode delay bandwidth metrics at 953 nm to deliver laser-optimized
performance over a wavelength range in the vicinity of 850 nm to 950 nm. A1a.2 complies
with A1a.1 specifications. A1a.3 complies with A1a.2 specifications. A1a.4 complies with
A1a.3 specifications.
A1a.1, A1a.2, A1a.3 and A1a.4 are also specified for two levels of macrobend loss
performance that are distinguished by "a" or "b" suffix. Those with suffix "a" (i.e. A1a.1a,
A1a.2a, A1a.3a, A1a.4a) are specified to meet traditional macrobend loss performance levels.
Those with suffix "b" (i.e. A1a.1b, A1a.2b, A1a.3b and A1a.4b) are specified to meet
enhanced macrobend loss (i.e. lower loss) performance levels, and thereby also comply with
traditional macrobend loss performance.
The nomenclature for the A1a sub-category establishes a coding hierarchy that permits
designation of fibres with increasing specificity. For example, purchase orders for A1a fibres
may be filled by any of the models specified in Annex A, while purchase orders for A1a.2 may
be filled by A1a.2a or A1a.2b. As a result, where specifications and descriptions apply to all
models at lower hierarchical levels, only
...