Bsi bs en 60793 2 10 2016

NORME EUROPÉENNE English Version Optical fibres - Part 2-10: Product specifications - Sectional specification for category A1 multimode fibre IEC 60793-2-10:2015 Fibres optiques - Par

Terms and definitions

For the purposes of this document, the terms and definitions given in IEC 60793-2, the IEC 60793-1 series and IEC 61931 apply.

Abbreviations

EMBc calculated effective modal bandwidth

OMBc overfilled launch modal bandwidth calculated from differential mode delay (also known as OFLc)

NOTE 1 The fibre consists of a glass core with a graded index profile and a glass cladding in accordance with IEC 60793-2:2011, 5.1

NOTE 2 The term “glass” usually refers to material consisting of non-metallic oxides.

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 family specification

Table 1 – Dimensional attributes and measurement methods

Core-cladding concentricity error IEC 60793-1-20

Primary coating non-circularity IEC 60793-1-21

Primary coating-cladding concentricity error IEC 60793-1-21

According to IEC 60793-1-22, the core diameter for A1 fibres, excluding A1a.1b/2b/3b fibres, is specified at 850 nm ± 10 nm with a test specimen length of 2.0 m ± 0.2 m and a threshold value, k CORE, of 0.025 For A1a.1b/2b/3b fibres, the core diameter is also set at 850 nm ± 10 nm, but with a test specimen length of 100 m ± 5% and the same threshold value of k CORE at 0.025.

Table 2 – Dimensional requirements common to category A1 fibres

Primary coating diameter – uncoloured b àm 245 ± 10

Primary coating diameter – coloured b àm 250 ± 15

Primary coating-cladding concentricity error àm ≤ 12,5

Length requirements for fiber optics can differ and should be established between the supplier and the customer The specified limits on primary coating diameter are primarily applicable to telecommunications cables, although various other applications may utilize different primary coating diameters Below are several alternative nominal primary coating diameters and their tolerances (àm).

Table 3 – Additional dimensional attributes required in family specifications

Cladding non-circularity Core diameter

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

Table 5 – Mechanical requirements common to category A1 fibres

Tensile strength (median) for 0,5m specimen length

The stress corrosion susceptibility constant \( n \) is defined as \( d \geq 18 \) The proof test value of 0.69 GPa corresponds to approximately 1% strain or a force of about 8.8 N for A1a and A1b fibers For details on the relationship between these units, refer to IEC TR 62048 Additionally, either the average strip force or peak strip force, as defined in the test procedure, can be specified by mutual agreement between the supplier and the customer.

Transmission requirements

Transmission attributes and measurement methods are given in Table 6

Table 6 – Transmission attributes and measurement methods

Change of optical transmission IEC 60793-1-46

Differential mode delay, as outlined in IEC 60793-1-49, utilizes either overfilled launch (OFL) or overfilled launch modal bandwidth calculated from differential mode delay (OMBc) for modal bandwidth assessment OMBc serves as the reference test method for A1a fibres at a wavelength of 850 nm, which is specified within a range of 850 nm ± 10 nm and requires a test specimen length of 1,000 m ± 5% The numerical aperture is defined at 850 nm ± 10 nm with a test specimen length of 2 m ± 0.2 m, maintaining a threshold value of k NA = 0.05 for A1 fibres, excluding A1a.1b/2b/3b fibres For A1a.1b/2b/3b fibres, the numerical aperture is specified at 850 nm ± 10 nm with a test specimen length of 100 m ± 5% and the same threshold value of k NA = 0.05 Additionally, differential mode delay is specified at 850 nm ± 10 nm with a test specimen length of 1,000 m ± 5% for A1a fibres.

Specification compliance of chromatic dispersion can be assured by compliance to the numerical aperture specification

Table 7 – Additional transmission attributes required in family specifications

Modal bandwidth Chromatic dispersion Numerical aperture Macrobending loss

The family specification for attenuation coefficient and modal bandwidth includes ranges of specifiable values rather than fixed limits The maximum attenuation coefficient and minimum modal bandwidth at 850 nm and 1,300 nm must be mutually agreed upon by the supplier and customer For commercial applications, the modal bandwidth is normalized linearly to 1 km.

For guidance purposes on bandwidth, Table H.1 shows a number of internationally standardised applications supported by A1 fibres, and Table H.2 gives a (limited) number of frequently used commercial bandwidth specifications for A1a and A1b fibres

The maximum attenuation values specified are applicable to uncabled optical fibers For the maximum attenuation values of cabled fibers, refer to IEC 60794-1-1, which should be used alongside this standard.

Remarks on the specification of modal bandwidth:

When specifying dual wavelength bandwidths for category A1 fibres, it is crucial to consider the relationship between the bandwidths at 850 nm and 1,300 nm, as illustrated in Figure 1, which depends on the refractive index parameter, g (refer to IEC 60793-2:2011, 5.1) The shaded region under the curve in Figure 1 represents the dual window area, where fibre manufacturers can optimize production by focusing on wavelengths at 850 nm, 1,300 nm, or a point in between.

The optimization of the manufacturing process leads to certain bandwidth combinations becoming unachievable For instance, producing a fiber that simultaneously achieves the maximum of both specified bandwidth ranges, such as 800 MHz⋅km and 1,000 MHz⋅km for A1b multimode fibers, is virtually impossible.

Figure 1 – Relation between bandwidths at 850 nm and 1 300 nm

Environmental requirements

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

Normalised bandwidth at 1 300 nm (MHz⋅km)

N or m al is ed ba ndw idt h at 85 0 nm ( M H z • k m)

Table 9 – Attributes measured for environmental tests

Change in optical transmission IEC 60793-1-46

Periodic type-tests are conducted for fiber and coating designs Unless specified otherwise, the recovery period between the end of environmental exposure and the attribute measurements must adhere to the guidelines outlined in the specific environmental test method.

Mechanical environmental requirements (common to all fibres in

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

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 (N) Peak strip force (N)

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 specimen length: 0,5 m

15th percentile tensile strength specimen length: 0,5 m

NOTE These requirements do not apply to hermetically coated fibre

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

NOTE This requirement does not apply to hermetically coated fibre.

Transmission environmental requirements

The change in attenuation from the initial value must be lower than the values specified in Table 13 Attenuation should be measured regularly throughout the exposure to each environment and after removal.

Table 13 – Change in attenuation for environmental tests

Environment Wavelength nm Attenuation increase dB/km

Family specifications for A1a multimode fibres

General

Annex A outlines specific requirements for A1a fibres, with common requirements referenced from the sectional specification for convenience Notably, relevant notes from the sectional specification are indicated with a superscript "SS" rather than being repeated.

Type A1a is a graded index fibre with a core diameter of 50/125 µm, categorized into three bandwidth models: A1a.1, A1a.2, and A1a.3 These models utilize overfilled bandwidth metrics for specification, while A1a.2 and A1a.3 additionally incorporate differential mode delay metrics to define two specific bandwidth grades for 850 nm laser-optimized 50/125 µm fibres.

The three bandwidth grades are categorized based on two levels of macrobend loss performance, indicated by the suffixes “a” and “b.” The grades with the “a” suffix, such as A1a.1a, A1a.2a, and A1a.3a, are designed to meet traditional macrobend loss performance standards In contrast, those with the “b” suffix, including A1a.1b, A1a.2b, and A1a.3b, are engineered to achieve enhanced macrobend loss performance, resulting in lower loss levels.

The A1a family nomenclature creates a coding hierarchy that allows for the designation of fibers with greater specificity For instance, purchase orders for A1a fibers can be fulfilled by any models listed in Annex A, while orders for A1a.2 can be satisfied by either A1a.2a or A1a.2b Consequently, when specifications and descriptions pertain to all models at lower hierarchical levels, only the common root is mentioned.

The dimensional, mechanical and environmental requirements are common to all and specified in Tables A.1 and A.2 The common and distinguishing transmission requirements are specified in Table A.3.

Table A.1 contains dimensional requirements specific to A1a fibres

Table A.1 – Dimensional requirements specific to A1a fibres

Core-cladding concentricity error àm ≤ 2

Primary coating diameter – uncoloured àm 245 ± 10 4.1

Primary coating diameter – coloured àm 250 ± 15 4.1

Primary coating-cladding concentricity error àm ≤ 12,5 4.1

Table A.2 contains the mechanical requirements specific to A1a fibres

Table A.2 – Mechanical requirements specific to A1a fibres

Proof stress level GPa ≥ 0,69 SS 4.2

Average strip force SS N 1,0 ≤ F avg ≤ 5,0 4.2

Peak strip force SS N 1,0 ≤ F peak ≤ 8,9 4.2

Table A.3 contains transmission requirements specific to A1a fibres

Table A.3 – Transmission requirements specific to A1a fibres

Minimum modal bandwidth-length product for overfilled launch at 850 nm MHz⋅km 500 1 500 3 500 4.3

(Table 6) Minimum modal bandwidth-length product for overfilled launch at

Differential mode delay at 850 nm ps/m Not specified Meet

Bending radius Number of turns dB A1a.1a A1a.2a A1a.3a

Bending radius Number of turns dB A1a.1b A1a.2b A1a.3b

- from 1 310 nm ≤ λ 0 ≤ 1 340 nm ps/nm 2 ⋅km

The macrobending loss measurement must adhere to the launch conditions specified in IEC 61280-4-1 The maximum chromatic dispersion coefficient at 850 nm is noted as S₀ = 0.09375 ps/nm²∙km at a wavelength of λ₀ = 1,340 nm, or S₀ = 0.10125 ps/nm²∙km at λ₀ = 1,320 nm, resulting in a worst-case scenario of -104 ps/nm∙km.

The requirements of 4.4 shall be met

Family specifications for A1b multimode fibres

General

Annex B outlines specific requirements for A1b fibres, with common requirements referenced from the sectional specification for convenience Notably, relevant notes from the sectional specification are indicated with a superscript "SS" rather than being repeated.

Type A1b fibre is a 62,5/125 àm graded index fibre.

Table B.1 contains dimensional requirements specific to A1b fibres

Table B.1 – Dimensional requirements specific to A1b fibres

Table B.2 contains the mechanical requirements specific to A1b fibres

Table B.2 – Mechanical requirements specific to A1b fibres

Table B.3 contains transmission requirements specific to A1b fibres

Table B.3 – Transmission requirements specific to A1b fibres

Maximum attenuation coefficient at 850 nm dB/km 3,0

Maximum attenuation coefficient at 1 300 nm dB/km 1,0

Minimum modal bandwidth at 850 nm MHz⋅km 200

Minimum modal bandwidth at 1 300 nm MHz⋅km 500

100 turns on bending radius of 37,5 mm at wavelengths 850 nm and 1 300 nm a dB 0,5

− from 1 348 nm ≤ λ 0 ≤ 1 365 nm ps/nm 2 ⋅km

≤ 0,001 (1 458 – λ 0 ) b a The launch condition for the macrobending loss measurement shall fulfil that described in IEC 61280-4-1 b The worst case chromatic dispersion coefficient at 850 nm (S 0 = 0,11 ps/nm 2 ∙km at λ 0 = 1 348 nm) is

Family specifications for A1d multimode fibres

General

Annex C contains particular requirements for A1d fibres Common requirements, repeated here for ease of reference from the sectional specification, are noted by an entry in the

“Reference” column Relevant notes from the sectional specification are not repeated but indicated with a superscript “ SS ”

Type A1d fibre is a 100/140 àm graded index fibre.

Table C.1 contains dimensional requirements specific to A1d fibres

Table C.1 – Dimensional requirements specific to A1d fibres

Table C.2 contains the mechanical requirements specific to A1d fibres

Table C.2 – Mechanical requirements specific to A1d fibres

Table C.3 contains transmission requirements specific to A1d fibres

Table C.3 – Transmission requirements specific to A1d fibres

Maximum attenuation coefficient at 850 nm a dB/km 3,5 to 7,0

Minimum modal bandwidth at 850 nm a MHz⋅km 10 to 200

Minimum modal bandwidth at 1 300 nm a MHz⋅km 100 to 300

Maximum macrobending loss dB For further study

− from 1 365 nm ≤ λ 0 ≤ 1 385 nm ps/nm 2 ⋅km

≤ 0,000 5 (1 575 – λ 0 ) b a The limit column forms a range of values that may be specified b The worst case chromatic dispersion coefficient at 850 nm (S 0 = 0,105 ps/nm 2 ∙km at λ 0 = 1 365 nm) is

Fibre differential mode delay (DMD) and calculated effective modal bandwidth (EMBc) requirements

A1a.2 fibre DMD requirements

General

A1a.2 fibres selected using the DMD mask method shall meet the requirements of D.1.2 and D.1.3 The radial limits, R INNER and R OUTER , were established for transmitters meeting the requirements of Clause E.2

Refer to Annex E for information regarding effective modal bandwidth (EMB).

DMD templates

A1a.2 fibres shall meet at least one of the six templates in Table D.1, each of which includes an inner and outer mask requirement, when measured according to IEC 60793-1-49

Table D.1 – DMD templates for A1a.2 fibres

Template number Inner mask DMD (ps/m) for

R INNER = 5 àm to R OUTER = 18 àm Outer mask DMD (ps/m) for

R INNER = 0 àm to R OUTER = 23 àm

Figure D.1 illustrates the DMD requirements outlined in D.1.2, showing the allowable DMD as per IEC 60793-1-49 against the radial offset position of the single mode probe A trade-off exists between the tightness of the inner and outer masks to ensure that an adequate amount of baud energy from the transmitter meets the launch specifications and arrives within the time constraints defined by the baud rate of the transmission system.

The inner mask's "floating" feature, depicted in Figure D.1, allows it to be positioned vertically anywhere within the outer mask's range of 0 àm to 23 àm This design enables the Digital Micromirror Device (DMD) to be more tightly constrained within the inner mask, which in turn permits looser tolerances on the outer mask, enhancing the manufacturing of fiber to meet these specifications For the 0.33 ps/m mask, the requirements remain consistent across the entire range from 0 àm to 23 àm, resulting in a "flat" mask.

IEC 60793-1-49 establishes a minimum effective modal bandwidth-length product when utilizing compliant sources By aligning the launch conditions of transmitters with the DMD requirements of the fiber, a balance between fiber and transmitter tolerances can be achieved Comprehensive studies involving fibers from various manufacturers and laser transmitters, along with detailed simulations, demonstrate that these coupled specifications can achieve a minimum effective modal bandwidth-length product of 2,000 MHz⋅km.

Utilizing a template for DMD values effectively balances the properties of the transmitter and fiber By limiting the transmitter encircled flux at a 4.5 µm radius, minimal energy is transmitted by the lowest order modes, which permits a more lenient tolerance on the modal structure excited at smaller radii Similarly, restricting the encircled flux at a 19 µm radius ensures that the highest order modes carry negligible energy, allowing for relaxed tolerances on the modal structure at larger radii.

DMD interval masks

The A1a.2 fibre DMD shall not exceed 0,25 ps/m for any of the radial offset intervals given in Table D.2

Outer mask Inner mask Outer mask

Radial offset (àm) Radial offset (àm)

TEM PL A TE 1 Inner mask floats inside outer mask

Outer mask Inner mask Outer mask

Outer mask Inner mask Outer mask Outer mask Inner mask Outer mask

TEM PL A TE 3 TEM PL A TE 6

Inner mask floats inside outer mask

Table D.2 – DMD interval masks for A1a.2 fibres

Interval number R INNER àm R OUTER àm

Interval masks effectively filter out fibers with rapidly changing DMD over short radial distances Fibers that successfully pass through this screening exhibit reduced inter-symbol interference compared to those that do not.

A1a.2 fibre EMBc requirements

General

A1a.2 fibres selected using the EMB c method shall meet the requirements of D.2.2.

Calculated effective bandwidth

The DMD optical pulse shapes can be adjusted using a specific set of launch distributions to derive a corresponding set of EMB c values To satisfy the requirements outlined in Equation D.1, the minimum EMB c (minEMB c) from this set must be achieved.

Minimum EMB c ≥ 1 770 MHz⋅km (D.1) where minimum EMB c is determined from the complex transfer function as described in IEC 60793-1-49 using the weights defined in Table D.3

NOTE 1 Minimum EMB c is a fibre parameter and its value may not be optimal for use in system models Refer to Annex E for information regarding the corresponding system parameter called the effective modal bandwidth (EMB)

NOTE 2 Refer to Annex F for additional explanation of bandwidth nomenclature

Table D.3 presents weightings for DMD measured at 1àm radial intervals from the core center (r = 0) for ten simulated lasers, reflecting encircled flux (EF) metrics of ten real lasers These DMD weightings are tailored for sources that comply with the specifications outlined in Clause E.2.

Radial position Laser ID r (àm) 1 2 3 4 5

Radial position Laser ID r (àm) 6 7 8 9 10

A1a.3 DMD requirements

General

Fibres chosen through the DMD mask method must comply with the specifications outlined in D.3.2 and D.3.3, as detailed in Clause D.1 Additionally, the radial limits, R INNER and R OUTER, have been defined for transmitters that satisfy the criteria set forth in Clause E.2.

Refer to Annex E for information regarding effective modal bandwidth (EMB).

DMD templates

A1a.3 fibres shall meet at least one of the three templates in Table D.4, each of which includes an inner and outer mask requirement, when measured according to IEC 60793-1-49.

Table D.4 – DMD templates for A1a.3 fibres

Template number Inner mask DMD (ps/m) for

Outer mask DMD (ps/m) for

DMD interval masks

The A1a.3 fibre DMD shall not exceed 0,11 ps/m for any of the radial offset intervals given in Table D.5 when measured according to IEC 60793-1-49

Table D.5 – DMD interval masks for A1a.3 fibres

Interval number R INNER àm R OUTER àm

A1a.3 fibre EMBc requirements

General

A1a.3 fibres selected using the EMB c method shall meet the requirements of D.4.2 See Clause D.2 for supporting information.

Calculated effective bandwidth

The DMD optical pulse shapes can be adjusted using various launch distributions to establish a corresponding set of EMB c values The minimum EMB c (minEMB c) from this set must satisfy the criteria outlined in Equation D.2.

Minimum EMB c ≥ 4 160 MHz⋅km (D.2) where minimum EMB c is determined from the complex transfer function as described in IEC 60793-1-49 using the weights defined in Table D.3

Modal bandwidth considerations and transmitter requirements

Background

When using multimode fibre with laser transmitters, the bandwidth can significantly vary based on the modal structure of the lasers, the fibre's modal delay characteristics, and the coupling between the laser and fibre modes Specifically, modal bandwidth refers to the -3 dB bandwidth of the impulse response generated from the modal delays of a specific fibre, which is influenced by the mode power distribution excited by the laser.

Understanding the modal structure of a fiber, as outlined by IEC 60793-1-49, establishes a minimum bandwidth range that can be expected when utilizing a specific fiber with different laser transmitters.

Using lasers that primarily couple into modes with well-defined delays ensures minimum modal bandwidth The IEC 61280-1-4 standard is applicable for measuring the launch conditions of laser transmitters into multimode fiber By carefully selecting launch condition specifications, it is possible to limit the fiber modes utilized by the transmitters to those with suitably restricted differential mode delays.

A minimum modal bandwidth-length product can be ensured by combining a transmitter meeting the specifications in Clause E.2 below with a 50 àm fibre meeting the specifications in Annex D.

Transmitter encircled flux (EF) and centre wavelength requirements

Encircled flux

The DMD radial limits for the inner, outer, and interval masks, along with the DMD weightings, were defined based on specific laser launch conditions These conditions are detailed in Equations E.1 and E.2 It is important to note that the minimum modal bandwidth for launch conditions outside this specified range has not been established, and it is expected to be lower than that for conditions within the defined range.

The power distribution of the transmitter launch condition must comply with the criteria outlined in Equations E.1 and E.2, as specified in IEC 61280-1-4 [15], while ensuring that the transmitter is connected to a 50-µm fiber that adheres to the specifications of this document.

Centre wavelength

To optimize modal bandwidth performance across various fibers, the transmitter's center wavelength should be maintained near the nominal differential mode delay (DMD) measurement wavelength of 850 nm Additionally, it may be necessary to reduce the modal bandwidth when the transmitter operates outside this optimal wavelength range.

1 Numbers in square brackets refer to the Bibliography

850 nm [6] See TIA TSB-172 for an illustration of bandwidth roll-off for fibres with bandwidth similar to fibre type A1a.3 [14]

The laser transmitter centre wavelength (λ c ) should meet the requirements of Equation E.3 when tested according to IEC 61280-1-3 [16]

Several published or late-stage draft application standards meet the requirements of E.2 [20 to 22]

EMB

A detailed time-domain Monte-Carlo simulation was conducted to evaluate the performance of various DMD mask and weighting proposals for transmitters in compliance with E.2 specifications The effectiveness of these proposals was assessed based on their ability to limit inter-symbol interference (ISI) to a rate not exceeding 0.5% The specific ISI threshold was determined using the IEEE 802.3ae link budget spreadsheet, considering factors such as transmitter rise time, receiver bandwidth, and a fibre with a modal bandwidth of 2,000 MHz⋅km Consequently, the Monte-Carlo simulation demonstrated that fibres conforming to type A1a.2 achieve a minimum effective modal bandwidth (EMB) of 2,000 MHz⋅km.

The minimum Effective Modal Bandwidth (EMB) value corresponds with the IEEE 802.3ae link budget spreadsheet assumptions, particularly noting that the Inter-Symbol Interference (ISI) impairment is modeled using Gaussian waveform assumptions for both the transmitter and fiber outputs Results from Monte-Carlo simulations indicate that the spreadsheet's relationship between ISI and minimum fiber modal bandwidth is overly pessimistic Consequently, the EMB calculation from weighted Differential Mode Delay (DMD) incorporates a factor of 1.13 to reconcile the fiber requirements established through time-domain Monte-Carlo simulations with the spreadsheet model, as illustrated in Equation E.4.

If other models are used, then a different EMB may be appropriate

Fibres that meet the criteria of Clauses D.3 and D.4 (A1a.3 fibres) offer a minimum modal bandwidth at 850 nm that is 2.35 times greater than that of fibres complying with Clauses D.1 and D.2 (A1a.2 fibres) Consequently, their minimum effective modal bandwidth (EMB) is also 2.35 times higher, based on the same link budget spreadsheet assumptions outlined in Equation E.5.

EMB ≥ 2,35 × 2 000 MHz⋅km ≥ 4 700 MHz⋅km (E.5) System performance studies with actual fibres and laser sources support this relationship

Table F.1 provides explanations of bandwidth parameters that have similar names and abbreviations

Parameter name and abbreviation Parameter description

(EMBc) The calculated modal bandwidth resulting from a particular weighting of a particular DMD

Minimum calculated effective modal bandwidth (minimum EMBc) or (min EMBc) The minimum calculated modal bandwidth resulting from a particular set of weightings of a particular DMD

Effective modal bandwidth (EMB) is determined by multiplying the minimum calculated effective modal bandwidth by 1.13, ensuring alignment with the IEEE 802.3ae link model assumptions for transmitters that comply with Clause E.2.

Preliminary indications for items needing further study

Effective modal bandwidth (EMB) at 1 300 nm

Chromatic dispersion properties enable the conversion of differential mode delay (DMD) measurements from one wavelength to another For instance, DMD measured at 850 nm can be utilized to estimate the minimum effective modal bandwidth-length product at 1,300 nm Initial engineering assessments suggest that fibers compliant with Annex D for ≥ 2,000 MHz⋅km effective modal bandwidth (EMB) at 850 nm will also achieve ≥ 500 MHz⋅km EMB at 1,300 nm.

1,300 nm laser-based transmitters are designed for use with both multimode and single mode fiber To ensure that multimode fibers meet their minimum overfilled bandwidth-length product for 1,300 nm transmitters intended for single mode fiber, such as 1000BASE-LX, IEEE 802.3 mandates the use of offset-launch mode-conditioning patch cords when connecting these transmitters to multimode fiber.

The offset-launch technique involves connecting a single mode fibre to a multimode fibre in a patch cord with a specific radial offset This method allows for an off-centre launch from the single mode fibre into the multimode fibre, exciting multiple modes and resulting in a mode power distribution that resembles an overfilled launch, rather than the native launch that primarily excites low-order modes.

Overfilled-launch bandwidth measurements are primarily influenced by high-order mode behavior, making them less sensitive to low-order modes By minimizing the excitation of low-order modes, the offset-launch patch cord reduces reliance on these poorly characterized modes, thereby enhancing the correlation between minimum system bandwidth and overfilled launch bandwidth-length measurements.

The DMD test procedure effectively measures low-order mode behavior, allowing it to establish a lower limit for the bandwidth-distance product of 1300 nm transmitters Fibers that comply with A1a.2 and A1a.3 specifications are optimized for peak bandwidth at 850 nm and are designed to limit low-order mode DMD.

Operating at wavelengths different from the peak wavelength leads to a systematic increase in Differential Mode Delay (DMD), with the most significant increase observed in the highest order modes The overfilled bandwidth, primarily influenced by high-order mode DMD, serves as a conservative indicator of the lowest effective modal bandwidth for native 1300 nm launches that focus power in low order modes Consequently, A1a.2 and A1a.3 fibers are anticipated to deliver Effective Modal Bandwidth (EMB) at least equal to their minimum overfilled bandwidth-length product of 500 MHz⋅km at 1300 nm, without requiring mode conditioning patch cords.

Scaling of EMB with DMD

Effective modal bandwidth-length products can be obtained from the templates and interval masks specified in Clauses D.1 and D.3 by scaling the effective modal bandwidth (EMB) inversely with the DMD temporal width, given that three specific conditions are satisfied.

1) the fibre is used with transmitters meeting the specifications in Clause E.2,

2) the radial offset limits of the templates are not changed, and

3) the overfilled modal bandwidth-length product requirements are scaled in direct proportion to the EMB

The scaling ability is supported by relationships derived from waveguide theory, where the mode power distribution of the transmitter is directly linked to the radial extents of the inner and outer DMD masks To minimize changes in modal bandwidth due to wavelength, operation must remain close to the nominal DMD measurement wavelength With fixed mode power distribution and DMD mask extents, scaling is facilitated by the inverse relationship between rms pulse width and bandwidth Here, the rms pulse width corresponds to the DMD temporal width By scaling the overfilled bandwidth in direct proportion to the desired EMB, the established proportionality between the DMD and overfilled bandwidth is preserved.

An effective modal bandwidth-length product of at least 1,000 MHz⋅km at 850 nm can be achieved with fiber that meets any of the six DMD templates specified in Clause D.1 Each template should have double the DMD temporal width in both the inner and outer masks, along with an overfilled bandwidth-length product of at least 750 MHz⋅km.

Internationally standardised applications

Table H.1 presents a range of internationally standardized applications, along with additional recommended applications, that are compatible with A1 fibres as outlined in this standard While this list is not comprehensive, it indicates that numerous other applications not explicitly mentioned may also be supported.

Table H.1 – Some internationally standardised applications supported by A1a and A1b fibres

10BASE-F ISO/IEC/IEEE 8802-3 FO CSMA/CD

100BASE-FX IEEE 802.3 Fast Ethernet

1000BASE-SX IEEE 802.3 Gigabit Ethernet

1000BASE-LX IEEE 802.3 Gigabit Ethernet

Token Ring ISO/IEC 8802-5 FO station attachment

FDDI ISO/IEC 9314-3 Fibre Distributed Data Interface PMD

LCF FDDI ISO/IEC 9314-9 Low cost Fibre PMD

HIPPI ISO/IEC 11518-1 High Perform Parallel I/F

ATM LAN 155,52 Mb/s ATM af-phy-0062.000 ATM-155 Multimode OF

ATM LAN 622,08 Mb/s ATM af-phy-0046.000 ATM-622 Multimode OF

10GBASE-LX4 IEEE 802.3 10-Gigabit Ethernet

10GBASE-LRM IEEE 802.3 10-Gigabit Ethernet

40GBASE-SR4 IEEE 802.3 40-Gigabit Ethernet

Used commercial bandwidth specifications

Table H.2 shows some frequently used commercial bandwidth specifications for A1a and A1b fibres This list is not exhaustive and many other specifications not listed here may be used in the market

Table H.2 – Typically used commercial bandwidth specifications for A1a and A1b graded-index multimode fibres

Fibre type Minimum modal bandwidth for OFL a condition (unless otherwise indicated) at 850 nm (MHz⋅km)

Minimum modal bandwidth for OFL a condition (unless otherwise indicated) at 1 300 nm(MHz⋅km)

A1a.1 500 500 Medium bit rate/medium distance

2 000 EMB b 500 Very high bit rate (10 Gb/s) / long distance; 850 nm optimised

4 700 EMB b 500 Very high bit rate (≥ 10 Gb/s) / long distance; 850 nm optimised

A1b 200 500 Medium bit rate/medium distance a OFL = Overfilled launch b EMB = Effective modal bandwidth (see Annexes D, E, F and G)

Cross reference of fibre types in this standard and ISO/IEC 11801

This standard outlines the specifications for fibre types A1a.1 and A1b, which adhere to the performance categories OM1 and OM2 of ISO/IEC 11801, featuring various core diameters and a defined bandwidth cell The requirements for fibre type A1a.2 align with those of OM3 as per ISO/IEC 11801, while the specifications for fibre type A1a.3 are anticipated to match the OM4 requirements upon the next update of ISO/IEC 11801 A cross-reference can be found in Table H.3.

Table H.3 – Cross reference between this standard and ISO/IEC 11801

ISO/IEC designation A1b A1a.1 A1a.2 A1a.3 OM1 OM2 OM3 OM4

IEC fibre type cross reference - - - - A1a.1 A1b A1a.1 A1b A1a.2 A1a.3

Minimum modal bandwidth-length product for overfilled launch at

Minimum effective modal bandwidth- length product at

Not specified Not specified 2 000 4 700 Not specified Not specified 2 000 4 700

Normative references to international publications with their corresponding European publications

This document references essential materials that are crucial for its application For references with specific dates, only the cited edition is applicable In the case of undated references, the most recent edition of the referenced document, including any amendments, is relevant.

NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu

Publication Year Title EN/HD Year

Part 1: Measurement methods and test procedures

Part 1-20: Measurement methods and test procedures - Fibre geometry

Part 1-21: Measurement methods and test procedures - Coating geometry

Part 1-22: Measurement methods and test procedures - Length measurement

Part 1-30: Measurement methods and test procedures - Fibre proof test

Part 1-31: Measurement methods and test procedures - Tensile strength

Part 1-32: Measurement methods and test procedures - Coating strippability

Part 1-33: Measurement methods and test procedures - Stress corrosion susceptibility

Part 1-34: Measurement methods and test procedures - Fibre curl

Part 1-40: Measurement methods and test procedures - Attenuation

Publication Year Title EN/HD Year

Part 1-41: Measurement methods and test procedures - Bandwidth

Part 1-42: Measurement methods and test procedures - Chromatic dispersion

Part 1-43: Measurement methods and test procedures - Numerical aperture measurement

Part 1-46: Measurement methods and test procedures - Monitoring of changes in optical transmittance

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

Part 1-49: Measurement methods and test procedures - Differential mode delay

Part 1-50: Measurement methods and test procedures - Damp heat (steady state) tests

Part 1-51: Measurement methods and test procedures - Dry heat (steady state) tests

Part 1-52: Measurement methods and test procedures - Change of temperature tests

Part 1-53: Measurement methods and test procedures - Water immersion tests

Part 2: Product specifications - General EN 60793-2 2012 IEC 61280-4-1 - Fibre optic communication subsystem test procedures - Part 4-1: Installed cable plant - Multimode attenuation measurement

IEC/TR 61931 - Fibre optic - Terminology - -

4.4.2 Mechanical environmental requirements (common to all fibres in category A1) 14

(normative) Family specifications for A1a multimode fibres 16

(normative) Family specifications for A1b multimode fibres 19

(normative) Family specifications for A1d multimode fibres 21

(normative) Fibre differential mode delay (DMD) and calculated effective

Annex D modal bandwidth (EMBc) requirements 23

(informative) Modal bandwidth considerations and transmitter requirements 29

E.2 Transmitter encircled flux (EF) and centre wavelength requirements 29

Annex F (informative) Preliminary indications for items needing further study 32

G.1 Effective modal bandwidth (EMB) at 1 300 nm 32

G.2 Scaling of EMB with DMD 32

(informative) Applications supported by A1 fibres 34

H.3 Cross reference of fibre types in this standard and ISO/IEC 11801 35

(informative) 1-Gigabit, 10-Gigabit, 40-Gigabit and 100-Gigabit Ethernet

Figure 1 – Relation between bandwidths at 850 nm and 1 300 nm 13

Table 1 – Dimensional attributes and measurement methods 10

Table 2 – Dimensional requirements common to category A1 fibres 10

Table 3 – Additional dimensional attributes required in family specifications 10

Table 4 – Mechanical attributes and measurement methods 11

Table 5 – Mechanical requirements common to category A1 fibres 11

Table 6 – Transmission attributes and measurement methods 12

Table 7 – Additional transmission attributes required in family specifications 12

Table 9 – Attributes measured for environmental tests 14

Table 10 – Strip force for environmental tests 14

Table 11 – Tensile strength for environmental tests 14

Table 12 – Stress corrosion susceptibility for environmental tests 15

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.4 – DMD templates for A1a.3 fibres 28

Table D.5 – DMD interval masks for A1a.3 fibres 28

Table H.1 – Some internationally standardised applications supported by A1a and A1b fibres 34

Table H.2 – Typically used commercial bandwidth specifications for A1a and A1b graded-index multimode fibres 35

Table H.3 – Cross reference between this standard and ISO/IEC 11801 35

Table I.1 – Summary of 1 Gb/s, 10 Gb/s, 40 Gb/s and 100 Gb/s Ethernet requirements and capabilities (1 of 3) 37

Part 2-10: Product specifications – Sectional specification for category A1 multimode fibres

The International Electrotechnical Commission (IEC) is a global standardization organization that includes all national electrotechnical committees Its primary goal is to foster international cooperation on standardization in the electrical and electronic sectors To achieve this, the IEC publishes various documents, including International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS), and Guides The development of these publications is managed by technical committees, with participation from interested IEC National Committees and various international organizations Additionally, the IEC works closely with the International Organization for Standardization (ISO) under mutually agreed conditions.

The IEC's formal decisions on technical matters reflect a near-universal consensus, as each technical committee includes representatives from all interested National Committees.

IEC Publications serve as international recommendations endorsed by IEC National Committees Although every effort is made to ensure the accuracy of their technical content, IEC disclaims responsibility for their usage or any misinterpretations by end users.

To enhance global consistency, IEC National Committees commit to transparently implementing IEC Publications in their national and regional documents Any discrepancies between IEC Publications and their national or regional counterparts will be clearly highlighted.

The IEC does not issue attestation of conformity; instead, independent certification bodies offer conformity assessment services and, in certain cases, grant access to IEC conformity marks It is important to note that the IEC is not liable for any services performed by these independent certification bodies.

6) All users should ensure that they have the latest edition of this publication

IEC and its directors, employees, agents, and technical committee members are not liable for any personal injury, property damage, or other damages, whether direct or indirect, resulting from the publication, use, or reliance on this IEC Publication or any other IEC Publications, including any associated costs or legal fees.

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

This IEC Publication may contain elements that are subject to patent rights, and IEC is not responsible for identifying any of these rights.

International Standard IEC 60793-2-10 has been prepared by subcommittee 86A: Fibres and cables, of IEC technical committee 86: Fibre optics

This fifth edition cancels and replaces the fourth edition published in 2011 This edition constitutes a technical revision

This edition introduces key technical updates compared to the previous version, including the addition of enhanced macrobending multimode fibers A1a.1b, A1a.2b, and A1a.3b It also specifies the test wavelength and specimen length for core diameter (CD), numerical aperture (NA), differential mode delay (DMD), and establishes threshold values for CD and NA Furthermore, a specimen length for the 850 nm bandwidth of A1a and A1b fibers has been included.

The text of this standard is based on the following documents:

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 60793 series, published under the general title Optical fibres, can be found on the IEC website

The committee has determined that the publication's content will stay the same until the stability date specified on the IEC website at "http://webstore.iec.ch" After this date, the publication will be updated accordingly.

• replaced by a revised edition, or

The 'colour inside' logo on the cover of this publication signifies that it includes essential colors for a proper understanding of the content Therefore, it is recommended that users print this document using a color printer.

Part 2-10: Product specifications – Sectional specification for category A1 multimode fibres

This part of IEC 60793 is applicable to optical fibre types A1a, A1b, and A1d These fibres are used or can be incorporated in information transmission equipment and optical fibre cables

Type A1a pertains to 50/125 µm graded index fiber, with three defined bandwidth grades: A1a.1, A1a.2, and A1a.3 Each grade is categorized by two levels of macrobend loss performance, indicated by the suffixes “a” and “b.” The “a” suffix denotes compliance with traditional macrobend loss performance levels, while the “b” suffix indicates enhanced macrobend loss performance, characterized by lower loss levels.

Type A1b applies to 62,5/125 àm graded index fibre and A1d applies to 100/140 àm graded index fibre

Other applications encompass short reach, high bit-rate systems in telephony and local networks that transmit data, voice, and video services This includes on-premises intra-building and inter-building fiber installations, data centers, local area networks (LANs), storage area networks (SANs), private branch exchanges (PBXs), and various multiplexing uses, as well as outside telephone cable plant applications and other 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 standard and which are given in Clause 3;

• particular requirements applicable to individual fibre types or specific applications, which are defined in the normative family specification annexes

This document references essential documents that are crucial for its application For references with specific dates, only the cited edition is applicable, while for undated references, the most recent edition, including any amendments, is relevant.

IEC 60793-1 (all parts), Optical fibres – Part 1: Measurement methods and test procedures

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

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

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 60793-2:2011, Optical fibres – Part 2: Product specifications – General

IEC 61280-4-1, Fibre-optic communication subsystem test procedures – Part 4-1: Installed cable plant – Multimode attenuation measurement

IEC TR 61931, Fibre optic – Terminology

For the purposes of this document, the terms and definitions given in IEC 60793-2, the IEC 60793-1 series and IEC 61931 apply

EMBc calculated effective modal bandwidth

OMBc overfilled launch modal bandwidth calculated from differential mode delay (also known as OFLc)

NOTE 1 The fibre consists of a glass core with a graded index profile and a glass cladding in accordance with IEC 60793-2:2011, 5.1

NOTE 2 The term “glass” usually refers to material consisting of non-metallic oxides

Dimensional attributes and measurement methods are given in Table 1

Requirements common to all fibres in category A1 are indicated in Table 2

Table 1 – Dimensional attributes and measurement methods

Core-cladding concentricity error IEC 60793-1-20

Primary coating non-circularity IEC 60793-1-21

Primary coating-cladding concentricity error IEC 60793-1-21

According to IEC 60793-1-22, the core diameter for A1 fibres, excluding A1a.1b/2b/3b fibres, is specified at 850 nm ± 10 nm with a test specimen length of 2.0 m ± 0.2 m and a threshold value, k CORE, of 0.025 For A1a.1b/2b/3b fibres, the core diameter remains at 850 nm ± 10 nm, but the test specimen length is set at 100 m ± 5%, also with a threshold value, k CORE, of 0.025.

Table 2 – Dimensional requirements common to category A1 fibres

Primary coating diameter – uncoloured b àm 245 ± 10

Primary coating diameter – coloured b àm 250 ± 15

Primary coating-cladding concentricity error àm ≤ 12,5

Tiêu đề	Optical Fibres Part 2-10: Product Specifications — Sectional Specification For Category A1 Multimode Fibre
Trường học	British Standards Institution
Chuyên ngành	Standards
Thể loại	Standard
Năm xuất bản	2016
Thành phố	Brussels

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Số trang	50
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