NORME EUROPÉENNE English Version Optical fibres - Part 2-40: Product specifications - Sectional specification for category A4 multimode fibres IEC 60793-2-40:2015 Fibres optiques - Pa
Dimensional requirements
Relevant dimensional attributes and measurement methods are given in Table 2
Requirements common to all category A4 fibres are indicated in Table 3
Additional attributes that shall be specified in the family specifications for sub-categories A4f through A4h are given in Table 4
Table 2 – Dimensional attributes and measurement methods
Core-cladding concentricity error IEC 60793-1-20
According to IEC 60793-1-20, mechanical methods can be used to measure cladding diameter and non-circularity, provided they yield equivalent measurement uncertainty The core diameter is defined as (650 ± 10) nm, with a test specimen length of 2.0 m ± 0.2 m, and a threshold value k CORE of 2.5% for A4 fibres.
Table 3 – Requirements common to all category A4 fibres
The cladding diameter of the fiber varies according to the family specification, unless stated otherwise For fiber types A4a, A4b, A4c, and A4d, the core diameter is generally 15 µm to 35 µm smaller than the cladding diameter In contrast, the core diameter for fiber types A4e, A4f, A4g, and A4h varies and is specified in the family documentation Additionally, length requirements differ and should be mutually agreed upon by the supplier and customer.
Table 4 – Additional attributes required in A4f through A4h family specifications
Core non-circularity Core-cladding concentricity error
Mechanical requirements
General
Mechanical attributes, test methods, and requirements for buffered fibres can be found in IEC 60794-2-41
Relevant mechanical attributes and test methods are given in Table 5
Requirements common to all category A4 fibres are indicated in Table 6
Additional attributes that shall be specified in the family specifications for sub-categories A4f through A4h are given in Table 7
Table 5 – Mechanical attributes and test methods
Table 6 – Requirements common to category A4 fibres
Elongation at yield peak % ≥ 4,0 Tensile load at yield peak N a a Tensile load at yield peak varies and is listed in the family specification
Table 7 – Additional attributes required in family specification for sub-category A4f through A4h fibres
Tensile load to induce 4 % elongation
Tensile load test
The purpose of this test is to characterize the ability of the fibre to support a load during handling Its purpose is to obtain values of the fibre’s tensile strength
The fibre samples are subjected to a mechanical environment as specified below The test shall be carried out at the standard test conditions in compliance with IEC 60068-1
A typical load versus elongation curve for a plastic optical fibre demonstrates an initial monotonic increase in tensile load with applied elongation, reaching a peak known as the yield peak Following this peak, the load decreases as the sample experiences ductile, irreversible elongation, often accompanied by localized necking and drawing This process is referred to as yielding.
Figure 1 – Tensile load versus elongation for a plastic optical fibre
The length of the sample between two clamping devices shall be between 100 mm and
The tensile strength measuring apparatus, such as a vertical tensile tester, must ensure smooth and constant motion of the test fiber without causing any jerking It should be equipped to simultaneously measure and record the tensile force or load generated during the test Additionally, the clamping mechanism used to secure the fiber ends must be designed to avoid excessive stress, thereby preventing fiber breakage.
The tensile speed must be set at 100 mm/min (±10%) Yield strength and yield elongation are determined from the load-elongation curve outlined in section 3.2.2.2 Unless specified otherwise, it is essential to record the tensile load at the yield peak and the tensile load required to achieve 4% elongation.
NOTE Elongation to breaking point is not applicable to category A4 fibres
The family specifications outlined in the normative annexes detail the requirements for testing If a fibre sample fails at a clamping point, the test is deemed invalid, necessitating a retest It is essential to test a sufficient number of samples to enable statistical analysis.
Transmission requirements
Relevant transmission attributes and measurement methods are given in Table 8
Additional attributes required in the family specifications are indicated in Table 9
Table 8 – Transmission attributes and measurement methods
Modal bandwidth with RML IEC 60793-1-41
Macrobending loss is addressed in IEC 60793-1-47:2009, Method B, which emphasizes the importance of applying appropriate launching conditions for measuring attenuation and modal bandwidth, as outlined in IEC 60793-1-40 and IEC 60793-1-41 It is crucial to note that bandwidth is not necessarily linear with respect to length, with values referenced to 100 m of fiber For A4a to A4c and A4e fibers, the numerical aperture is specified at 650 nm ± 10 nm, with a test specimen length of 2.0 m ± 0.2 m and a threshold value k NA of 50% In contrast, A4d fibers require the numerical aperture to be determined at 650 nm ± 10 nm, using local minimums and related angles in the far-field intensity pattern, as per IEC 60793-1-43:2014, Technique 4 Additionally, for A4f to A4h fibers, the numerical aperture is specified at 850 nm ± 10 nm, with a test specimen length of 6.0 m ± 0.6 m and a threshold value k NA of 5%.
Table 9 – Attributes required in family specifications
Attenuation Modal bandwidth Numerical aperture Chromatic dispersion Macrobending loss
Environmental requirements
General
Environmental exposure tests and measurement methods are documented in two forms:
• relevant environmental attributes, test methods and test conditions given in Table 10;
• measurements of a particular mechanical and transmission attribute that may change during exposure to the environmental test listed in Table 11
Test condition a Environment Test method b Test condition c
Damp heat IEC 60793-1-50 +75 °C, 85 % RH, 30 days
Damp heat IEC 60793-1-50 +60 °C, 85 % RH, 30 days
The temperature change test conditions according to IEC 60793-1-52 specify a range of –20 °C to +70 °C, with the specific test condition (A or B) to be mutually agreed upon by the supplier and customer While the test methods do not explicitly state their relevance to A4 fibers, they should still be applied Additionally, the length of the test specimen must also be determined through agreement between the supplier and customer, and these test conditions take precedence over any previously specified conditions in the referenced test methods.
Change in optical transmission IEC 60793-1-46
These tests are normally conducted periodically as type-tests for a fibre design Unless otherwise specified:
• the specimen shall be pre-conditioned by keeping it at standard atmospheric conditions for at least 24 h, and
• the recovery period allowed between the completion of the environmental exposure and measuring the attributes shall be as stated in the particular environmental test method
Environmental exposure testing for sub-category A4a to A4e fibres is typically conducted after the fibres have been buffered, in accordance with IEC 60794-2-41, which outlines the environmental requirements for buffered fibres However, testing for unbuffered fibres is only necessary when these fibres are sold in their unbuffered state.
Mechanical environmental requirements
Tensile strength shall be verified following removal of the fibre from the environment but only after cooling down the specimen at standard atmospheric conditions
Table 12 – Requirement for tensile strength
Environment Elongation at yield peak
Transmission environmental requirements
The change in attenuation from the initial value must be lower than the specified limits in Table 13 and Table 14, with varying requirements for the two groups of fibers due to their distinct application environments.
Table 13 – Requirement for change in attenuation for A4a through A4e fibre
Damp heat Attenuation increase at 650 nm dB/100 m ≤ 5
(includes attenuation due to water absorption)
Dry heat Attenuation increase at 650 nm dB/100 m ≤ 2
Change of temperature Attenuation increase at 650 nm dB/100 m ≤ 2
Table 14 – Requirement for change in attenuation for A4f through A4h fibre
Damp heat Attenuation increase at 650nm,
850 nm and/or 1 300 nm a dB/100 m ≤ 1,0
(includes attenuation due to water absorption)
Dry heat Attenuation increase at 650 nm,
850 nm and/or 1 300 nm dB/100 m ≤ 0,5
Change of temperature Attenuation increase at 650 nm,
At 850 nm and/or 1,300 nm, the attenuation should not exceed 0.5 dB/100 m Due to the significant impact of absorbed water at 1,300 nm, it is essential to allow the sample to recover for a minimum of 24 hours under standard room temperature atmospheric conditions before measuring attenuation increases.
Family specifications for sub-category A4a multimode fibres
General
Annex A outlines specific requirements for sub-category A4a fibres, with common requirements highlighted in the "Reference" column for easy access.
Sub-category A4a fibre is a 1 000 àm cladding diameter step-index fibre.
Dimensional requirements
Table A.1 contains dimensional requirements specific to A4a fibres
Table A.1 – Dimensional requirements specific to A4a fibres
Mechanical requirements
Table A.2 contains mechanical requirements specific to A4a fibres
Table A.2 – Mechanical requirements specific to A4a fibres
Tensile load at yield peak N ≥ 56 3.2.2
Transmission requirements
Table A.3 contains transmission requirements specific to A4a fibres
Implementation A4a.1 refers to the A4a fibre sub-category defined in IEC 60793-2-40:2006, while Implementation A4a.2 represents an enhanced version of A4a fibre, offering improved attenuation and bandwidth for longer distance transmission compared to A4a.1 For details on 520 nm transmission over A4a.2 fibres, please refer to Annex J.
Table A.3 – Transmission requirements specific to A4a fibres
Attenuation at 650 nm when using an overfilled launch dB/100 m a ≤ 40 ≤ 40 3.3
Attenuation at 650 nm when using an equilibrium mode distribution launch c dB/100 m a ≤ 30 ≤ 18 3.3
Minimum modal bandwidth at 650 nm MHz over 100 m b 10 – 3.3
Minimum modal bandwidth at 650 nm using RML MHz over 100 m b – 40 3.3
Macrobending loss at 650 nm, with 10 turns around a 25 mm radius quarter circle, is limited to 0.5 dB The attenuation values are typically expressed in dB/100 m, which can be converted to dB/km by multiplying by 10 Similarly, bandwidth values are presented in MHz over 100 m and can be compared to MHz-km by dividing by 10 For further details, refer to Annex I.
Environmental requirements
The requirements of 3.4 shall be met
Family specifications for sub-category A4b multimode fibres
General
Annex B outlines specific requirements for sub-category A4b fibres, with common requirements highlighted in the "Reference" column for easy access.
Sub-category A4b fibre is a 750 àm cladding diameter step-index fibre.
Dimensional requirements
Table B.1 contains dimensional requirements specific to A4b fibres
Table B.1 – Dimensional requirements specific to A4b fibres
Mechanical requirements
Table B.2 contains mechanical requirements specific to A4b fibres
Table B.2 – Mechanical requirements specific to A4b fibres
Tensile load at yield peak N ≥ 32 3.2.2
Transmission requirements
Table B.3 contains transmission requirements specific to A4b fibres
Table B.3 – Transmission requirements specific to A4b fibres
Attenuation at 650 nm when using an overfilled launch dB/100 m a ≤ 40 3.3
Attenuation at 650 nm when using an equilibrium mode distribution launch c dB/100 m a ≤ 30 3.3
Minimum modal bandwidth at 650 nm MHz over 100 m b 10 3.3
Macrobending loss at 650 nm, with 10 turns around a 25 mm radius quarter circle, is limited to 0.5 dB The attenuation values are typically expressed in dB/100 m, which can be converted to dB/km by multiplying by 10 Similarly, bandwidth values are presented in MHz over 100 m and can be compared to MHz/km by dividing by 10 For further details, refer to Annex I.
Environmental requirements
The requirements of 3.4 shall be met
Family specifications for sub-category A4c multimode fibres
General
Annex C outlines specific requirements for sub-category A4c fibres, with common requirements highlighted in the "Reference" column for easy access.
Sub-category A4c fibre is a 500 àm cladding diameter step-index fibre.
Dimensional requirements
Table C.1 contains dimensional requirements specific to A4c fibres
Table C.1 – Dimensional requirements specific to A4c fibres
Mechanical requirements
Table C.2 contains mechanical requirements specific to A4c fibres
Table C.2 – Mechanical requirements specific to A4c fibres
Tensile load at yield peak N ≥ 14 3.2.2
Transmission requirements
Table C.3 contains transmission requirements specific to A4c fibres
Table C.3 – Transmission requirements specific to A4c fibres
Attenuation at 650 nm when using an overfilled launch dB/100 m a ≤ 40 3.3
Attenuation at 650 nm when using an equilibrium mode distribution launch c dB/100 m a ≤ 30 3.3
Minimum modal bandwidth at 650 nm MHz over 100 m b 10 3.3
Macrobending loss at 650 nm, with 10 turns around a 25 mm radius quarter circle, is limited to 0.5 dB The attenuation values are typically expressed in dB/100 m, which can be converted to dB/km by multiplying by 10 Similarly, bandwidth values are presented in MHz over 100 m and can be compared to MHz/km by dividing by 10 For further details, refer to Annex I.
Environmental requirements
The requirements of 3.4 shall be met
Family specifications for sub-category A4d multimode fibres
General
Annex D outlines specific requirements for sub-category A4d fibres, with common requirements highlighted in the “Reference” column for easy access.
Sub-category A4d fibre is a 1 000 àm cladding diameter double step-index fibre.
Dimensional requirements
Table D.1 contains dimensional requirements specific to A4d fibres
Table D.1 – Dimensional requirements specific to A4d fibres
Mechanical requirements
Table D.2 contains mechanical requirements specific to A4d fibres
Table D.2 – Mechanical requirements specific to A4d fibres
Tensile load at yield peak N ≥ 56 3.2.2
Transmission requirements
Table D.3 contains transmission requirements specific to A4d fibres
Table D.3 – Transmission requirements specific to A4d fibres
Attenuation at 650 nm when using an overfilled launch dB/100 m a ≤ 40 3.3
Attenuation at 650 nm using a launch
Minimum modal bandwidth at 650 nm using launch NA = 0,3 (RML) MHz over 100 m b 100 3.3
Macrobending loss at 650 nm, measured over 10 turns around a 25 mm radius quarter circle, is ≤ 0.5 dB The attenuation values are typically expressed in dB per 100 m, which can be converted to dB per km by multiplying by 10 Similarly, bandwidth values are presented in MHz per 100 m, allowing for comparison to MHz per km by dividing by 10.
Environmental requirements
The requirements of 3.4 shall be met
Family specifications for sub-category A4e multimode fibres
General
Annex E outlines specific requirements for sub-category A4e fibres, with common requirements highlighted in the “Reference” column for easy access.
Sub-category A4e fibre is a 750 àm cladding diameter, either multi-step-index or graded-index fibre.
Dimensional requirements
Table E.1 contains dimensional requirements specific to A4e fibres
Table E.1 – Dimensional requirements specific to A4e fibres
Mechanical requirements
Table E.2 contains the mechanical requirements specific to A4e fibres
Table E.2 – Mechanical requirements specific to A4e fibres
Tensile load at yield peak N ≥ 32 3.2.2
Transmission requirements
Table E.3 contains transmission requirements specific to A4e fibres
Table E.3 – Transmission requirements specific to A4e fibres
Attenuation coefficient at 650 nm using a launch NA = 0,3 dB/100m a ≤ 18 3.3
Minimum modal bandwidth at 650 nm using a launch NA = 0,3 MHz over 100 m b 200 3.3
Macrobending loss at 650 nm, with 10 turns around a 25 mm radius quarter circle, is measured at dB ≤ 0.5 The attenuation values are expressed in dB/100 m, which is typical for the fiber lengths used, and can be compared to dB/km by multiplying by 10 Similarly, bandwidth values are given in MHz over 100 m, reflecting standard fiber lengths, and can be converted to MHz-km by dividing by 10.
Environmental requirements
The requirements of 3.4 shall be met
Family specifications for sub-category A4f multimode fibres
General
Annex F outlines specific requirements for sub-category A4f fibres, with common requirements highlighted in the “Reference” column for easy access.
Sub-category A4f fibre is a 200/490 àm graded-index fibre.
Dimensional requirements
Table F.1 contains dimensional requirements specific to A4f fibres
Table F.1 – Dimensional requirements specific to A4f fibres
Core-cladding concentricity error àm ≤ 6 3.1
Mechanical requirements
Table F.2 contains the mechanical requirements specific to A4f fibres
Table F.2 – Mechanical requirements specific to A4f fibres
Tensile load at yield peak N ≥ 7 3.2.2
Tensile load to induce 4 % elongation N ≥ 7 3.2.2
Transmission requirements
Table F.3 contains transmission requirements specific to A4f fibres
Table F.3 – Transmission requirements specific to A4f fibres
Minimum modal bandwidth at 650 nm b MHz over 100 m c 800 3.3
Minimum modal bandwidth at 850 nm b MHz over 100 m c ≥ 1 500 d 3.3
Minimum modal bandwidth at 1300 nm b MHz over 100 m c ≥ 1 500 d 3.3
Macrobending loss at 850 nm (10 turns around a 25 mm radius quarter circle) e dB ≤ 1,25 3.3
The zero dispersion slope is defined as S 0 ps/(nm² ⋅ km) ≤ 0.06 A typical mandrel diameter of 60 mm is utilized when applying Method A according to IEC 60793-1-40:2001 Measurements are conducted under the overfilled launch condition as specified in IEC 60793-1-41 for A3 and A4 fibers, and are taken over lengths ranging from 100 to 500 meters The scaling method from the measurement length is also specified.
The reference length of 100 m is available upon request, as it reflects the typical fibre length used Bandwidth values in MHz over 100 m can be roughly converted to MHz-km by dividing by 10, with specific values to be agreed upon by the supplier and customer Measurements are taken using a 60 mm diameter mandrel launch Similarly, attenuation values in dB/100 m can be approximately converted to dB/km by multiplying by 10.
Environmental requirements
The requirements of 3.4 shall be met
Family specifications for sub-category A4g multimode fibres
General
Annex G outlines specific requirements for sub-category A4g fibres, with common requirements highlighted in the "Reference" column for easy access.
Sub-category A4g fibre is a 120/490 àm graded-index fibre.
Dimensional requirements
Table G.1 contains dimensional requirements specific to A4g fibres
Table G.1 – Dimensional requirements specific to A4g fibres
Core-cladding concentricity error àm ≤ 6 3.1
Mechanical requirements
Table G.2 contains the mechanical requirements specific to A4g fibres
Table G.2 – Mechanical requirements specific to A4g fibres
Tensile load at yield peak N ≥ 7 3.2.2
Tensile load to induce 4 % elongation N ≥ 7 3.2.2
Transmission requirements
Table G.3 contains transmission requirements specific to A4g fibres
Table G.3 – Transmission requirements specific to A4g fibres
Minimum modal bandwidth at 650 nm b MHz over 100 m c 800 3.3
Minimum modal bandwidth at 850 nm b MHz over 100 m c ≥ 1 880 d 3.3
Minimum modal bandwidth at 1300 nm b MHz over 100 m c ≥ 1 880 d 3.3
Macrobending loss at 850 nm (10 turns around a 25 mm radius quarter circle) e dB ≤ 0,6 3.3
The zero dispersion slope is defined as S 0 ps/(nm² ⋅ km) ≤ 0.06 A typical mandrel diameter of 60 mm is utilized when applying Method A according to IEC 60793-1-40:2001 Measurements are conducted under the overfilled launch condition as specified in IEC 60793-1-41 for A3 and A4 fibres, and are taken over lengths ranging from 100 to 500 m The scaling method from the measurement length is also considered.
For optimal performance, a reference length of 100 m should be available upon request, as this length is typical for fiber usage Bandwidth values in MHz over 100 m can be roughly converted to MHz-km by dividing by 10 The specific bandwidth value must be agreed upon by both the supplier and the customer Measurements should be taken using a 60 mm diameter mandrel launch Additionally, attenuation values in dB/100 m can be approximately converted to dB/km by multiplying by 10.
Environmental requirements
The requirements of 3.4 shall be met
Family specifications for sub-category A4h multimode fibres
General
Annex H outlines specific requirements for sub-category A4h fibres, with common requirements highlighted in the “Reference” column for easy access.
Sub-category A4h fibre is a 62,5/245 àm graded-index fibre.
Dimensional requirements
Table H.1 contains dimensional requirements specific to A4h fibres
Table H.1 – Dimensional requirements specific to A4h fibres
Core-cladding concentricity error àm ≤ 3 3.1
Mechanical requirements
Table H.2 contains the mechanical requirements specific to A4h fibres
Table H.2 – Mechanical requirements specific to A4h fibres
Tensile load at yield peak N ≥ 1,75 3.2.2
Tensile load to induce 4 % elongation N ≥ 1,75 3.2.2
Transmission requirements
Table H.3 contains transmission requirements specific to A4h fibres
Table H.3 – Transmission requirements specific to A4h fibres
Minimum modal bandwidth at 850 nm b MHz over 100 m c ≥ 1 880 d 3.3
Minimum Modal bandwidth at 1300 nm b MHz over 100 m c ≥ 1 880 d 3.3
Macrobending loss at 850 nm (10 turns around a 25 mm radius quarter circle) e dB ≤ 0,25 3.3
The zero dispersion slope is defined as S 0 ps/(nm² ⋅ km) ≤ 0.06 A common mandrel diameter of 20 mm is utilized when applying Method A according to IEC 60793-1-40:2001 Measurements are conducted under the overfilled launch condition as specified in IEC 60793-1-41 for A3 and A4 fibers, and are taken over lengths ranging from 100 to 500 meters The scaling method from the measurement length is also specified.
A reference length of 100 m is available upon request, as this length is typical for fiber usage Bandwidth values in MHz over 100 m can be roughly converted to MHz-km by dividing by 10 The specific bandwidth value must be agreed upon by both the supplier and the customer Measurements are taken using a 20 mm diameter mandrel launch Similarly, attenuation values in dB/100 m can be approximately converted to dB/km by multiplying by 10.
normative) Mode scramblers for sub-category A4a to A4d fibres
General
When measuring the equilibrium mode launch attenuation of sub-category A4a, A4b, and A4c fibres, use a figure 8-shaped mode scrambler (Figure I.1), such as described in IEC 60793-1- 40:2001, A.1.4
Figure I.1 – Mode scrambler for category A4 fibre
Specification for mode scramblers
The mode scrambler will be constructed using buffered A4 fiber that matches the sub-category of the fiber being tested The specifications for the mode scrambler are detailed in Table I.1.
Fibre sub- category Fibre length m
Distance between the two cylinders m
Additional transmission requirements for sub-category
A4a multimode fibres for wavelengths below 650 nm
General
Annex J outlines additional transmission requirements for the implementation of A4a.2 in sub-category A4a fibres, specifically for wavelengths below 650 nm PMMA-based fibres exhibit the lowest attenuation at approximately 520 nm and 560 nm The increasing availability of powerful transceivers utilizing GaN-LEDs enhances the appeal of designing improved transmission systems around the 520 nm optical window To support the development and application of these systems, specific requirements must be met.
Transmission requirements
Table J.1 contains additional transmission requirements specific to A4a.2 fibres
Table J.1 – Transmission requirements specific to A4a.2 fibre
Attenuation at 520 nm when using an equilibrium mode distribution launch c dB/100 m a ≤ 10 3.3
Minimum modal bandwidth at 520 nm when using an equilibrium mode distribution launch c
Macrobending loss at 520 nm, measured at 10 turns around a 25 mm radius quarter circle, is ≤ 0.5 dB The attenuation values are expressed in dB per 100 m, which is typical for actual fiber lengths, and can be compared to dB/km by multiplying by 10 Similarly, bandwidth values are given in MHz over 100 m and can be converted to MHz-km by dividing by 10 For further details, refer to Annex I.
IEC 60793-1-1, Optical fibres – Part 1-1: Measurement methods and test procedures – General and guidance
IEC 60793-2, Optical fibres − Part 2: Product specifications – General
IEC 60793-2-40: 2006, Optical fibres – Part 2-40: Product specifications – Sectional specification for category A4 multimode fibres 1
IEC 60794-2-41, Optical fibre cables – Part 2-41: Indoor cables – Product specification for simplex and duplex buffered A4 fibres