IEC 61300-3-35:2015

IEC 61300-3-35 ®
Edition 2.0 2015-06
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures –
Part 3-35: Examinations and measurements –
Visual inspection of fibre optic connectors and fibre-stub transceivers

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IEC 61300-3-35 ®
Edition 2.0 2015-06
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Fibre optic interconnecting devices and passive components – Basic test and

measurement procedures –
Part 3-35: Examinations and measurements –

Visual inspection of fibre optic connectors and fibre-stub transceivers

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.20 ISBN 978-2-8322-2773-2

– 2 – IEC 61300-3-35:2015 RLV © IEC 2015

CONTENTS
FOREWORD . 4

1 Scope . 6

2 Normative references . 6

3 Terms, definitions and abbreviations . 6

3.1 Terms and definitions . 6

3.2 Abbreviations . 7

4 Measurement . 7

4.1 General . 7
4.2 Measurement conditions . 8
4.3 Pre-conditioning . 8
4.4 Recovery . 8
5 Apparatus . 8
5.1 Method A: Direct view optical microscopy . 8
5.2 Method B: Video microscopy . 9
5.3 Method C: Automated analysis microscopy . 9
5.4 Calibration Certification requirements for low and high resolution systems . 9
5.4.1 General . 9
5.4.2 Requirement for low resolution microscope systems . 9
5.4.3 Requirements for high resolution microscope systems . 9
6 Procedure . 10
6.1 Measurement regions .
6.1 Calibration Certification procedure . 10
6.2 Inspection procedure . 11
6.3 Visual requirements . 12
Annex A (informative) Examples of inspected end faces with defects surface anomalies . 16
Annex B (normative) Diagram of calibration qualification artefact and method of
manufacture . 27
B.1 High resolution artefact . 27
B.2 Low resolution artefact . 29
Bibliography . 30

Figure 1 – Inspection procedure flow . 12
Figure A.1 – Example 1 (low resolution system) . 22
Figure A.2 – Example 1 (high resolution system) . 22
Figure A.3 – Example 2 (low resolution system) . 22
Figure A.4 – Example 2 (high resolution system) . 23
Figure A.5 – Example 3 (low resolution system) . 23
Figure A.6 – Example 3 (high resolution system) . 24
Figure A.7 – Example 4 (low resolution system) . 24
Figure A.8 – Example 4 (high resolution system) . 25
Figure A.9 – Example 5 (low resolution system) . 25
Figure A.10 – Example 6 (low resolution system) . 26
Figure B.1 – Example of nano-indentation test system . 27

Figure B.2 – Example of high resolution artefacts . 28

Figure B.3 – Example of low resolution artefact pattern . 29

Table 1 – Measurement regions for single fibre connectors .

Table 2 – Measurement regions for multiple fibre rectangular ferruled connectors .

Table 3 1 – Visual requirements for single mode PC polished connectors, single mode

fibre, RL ≥ 45 dB . 13

Table 4 2 – Visual requirements for single mode angle polished connectors (APC),

single mode fibre . 13

Table 5 3 – Visual requirements for single-mode PC polished connectors, single-mode
fibre, RL ≥ 26 dB and single-mode transceivers using a fibre-stub interface . 14
Table 6 4 – Visual requirements for multi-mode PC polished connectors, multi-mode
fibres . 15

– 4 – IEC 61300-3-35:2015 RLV © IEC 2015

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
FIBRE OPTIC INTERCONNECTING
DEVICES AND PASSIVE COMPONENTS –

BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-35: Examinations and measurements –

Visual inspection of fibre optic connectors endface visual and automated

inspection and fibre-stub transceivers
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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This redline version of the official IEC Standard allows the user to identify the changes
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International Standard IEC 61300-3-35 has been prepared by subcommittee SC86B: Fibre optic

interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.

This second edition cancels and replaces the first edition published in 2009 and constitutes a

technical revision.
This edition includes the following significant technical changes with respect to the previous

edition:
a) modification to the title;
b) addition of some terms and definitions;

c) reconsideration of the specific values of Tables 1 to 4 to reflect the current market situation;
d) addition of visual requirements for single-mode transceivers using a fibre-stub interface in
Table 3;
e) addition of a sentence in 4.1 concerning the susceptibilty of the methods to system
variability.
The text of this standard is based on the following documents:
FDIS Report on voting
86B/3886/FDIS 86B/3912/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61300 series, published under the general title Fibre optic
interconnecting devices and passive components – Basic test and measurement procedures,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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.
– 6 – IEC 61300-3-35:2015 RLV © IEC 2015

FIBRE OPTIC INTERCONNECTING
DEVICES AND PASSIVE COMPONENTS –

BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-35: Examinations and measurements –

Visual inspection of fibre optic connectors endface visual and automated

inspection and fibre-stub transceivers

1 Scope
This part of IEC 61300 describes methods for quantitatively assessing the end face quality of a
polished fibre optic connector or of a fibre optic transceiver using a fibre-stub type interface.
The information is intended for use with other standards which set requirements for allowable
surface defects such as scratches, pits and debris which may affect optical performance. Sub-
surface cracks and fractures are not considered in this standard. In general, the methods
described in this standard apply to 125 m cladding fibres contained within a ferrule and
intended for use with sources of  2 W of input power. However, portions are applicable to non-
ferruled connectors and other fibre types. Those portions are identified where appropriate. It is
not the intention of this standard that the size of scratches should be measured, the dimensions
and requirements are selected such that they can be estimated. There is no need to measure
for example if a scratch is 2,3 µm wide.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
None Void.
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

3.1.1
defect
non-linear surface feature detectable on the end face of ferrule including particulates, other
debris, fluid contamination, pits, chips, edge chipping, etc.
Note 1 to entry: Some fibre types have structural features potentially visible on the fibre end face. Fibres that use
microstructures to contain the light signal, such as photonic band-gap and hole-assisted fibres, can have an
engineered or random pattern of structures surrounding the core. These features are not defects.
3.1.2
defect size
smallest circle that can encompass the entire defect

3.1.3
loose debris
particulate and debris that can be removed by cleaning

Note 1 to entry: Loose debris are classified as defects.

3.1.4
scratch
a permanent linear surface feature where the fiber or ferrule end face has been damaged or

removed, and where the width of the damaged area is small compared to its length

3.1.5
reliably detectable
sufficiently clear and visible so that a typical technician of average training would recognize the
feature at least 98 % of the time.
3.2 Abbreviations
Term Description
DUT Device under test
FOV Field of view
4 Measurement
4.1 General
The objective of this standard is to prescribe methods for quantitatively inspecting fibre optic
end faces to determine if they are suitable for use. Three methods are described:
A. direct view optical microscopy as described in 5.1;
B. video microscopy as described in 5.2;
C. automated analysis microscopy as described in 5.3.
Within each method, there are hardware requirements and procedures for both low resolution
and high resolution systems. High resolution systems are to be utilized for critical examination
of the glass fibre after polishing and upon incoming quality assurance. High resolution systems
are typically not used during field polishing or in conjunction with multimode connectors. Low
resolution systems are to be utilized prior to mating connectors for any purpose. All methods
require a means for measuring and quantifying defects. Low resolution systems should be used
for examination of single-mode and multi-mode connectors prior to mating and after polishing.

High resolution systems may be used for end face inspection in the factory after polishing of
single-mode connectors. High resolution systems are not required for inspection in the field nor
for inspection of multi-mode connectors nor for field polished connectors.
There are many types of defects. Commonly used terminology would include: particles, pits,
chips, scratches, embedded debris, loose debris, cracks, etc. For practical purposes, all
defects will be categorized in one of two groups. They are defined as follows:
scratches: permanent linear surface features;
defects: all non-linear features detectable on the fibre. This includes particulates, other debris,
pits, chips, edge chipping, etc.
All defects and scratches are surface anomalies. Sub-surface cracks and fractures are not
reliably detectable with a light microscope in all situations and are therefore not covered within

– 8 – IEC 61300-3-35:2015 RLV © IEC 2015

this standard. Cracks and fractures to the fibre may be detected with a light microscope and

are generally considered a catastrophic failure.

Differentiating between a scratch and all other defects is generally intuitive to a human being.

However, to provide clarity, and for automated systems, scratches are defined as being less than

4 m wide, linear in nature, and with a length that is at least 30 times their width. As the width

dimension is not practical to visually measure below 3 m, these figures can be grossly estimated.

Defects size is defined for methods A and B as the diameter of the smallest circle that can

encompass the entire defect. Defect size for method C can be either the actual measured surface

area or the diameter of the smallest circle than can encompass the entire defect.

Some fibre types have structural features potentially visible on the fibre endface. Fibres that use
microstructures to contain the light signal, such as photonic band-gap and hole-assisted fibres,
can have an engineered or random pattern of structures surrounding the core. These features are
not defects.
For methods A and B, it is recommended that visual gauge tools be developed to facilitate the
measurement procedure. For method A, an eyepiece reticule is recommended. For method B, an
overlay is recommended.
All methods are susceptible to system variability: Methods A and B are operator dependent;
Method C is operator independent.
4.2 Measurement conditions
No restrictions are placed on the range of atmospheric conditions under which the test can be
conducted. It may be performed in controlled or uncontrolled environments provided that the
end faces are carefully cleaned before the test.
4.3 Pre-conditioning
No minimum pre-conditioning time is required.
4.4 Recovery
Since measurements are to be made at standard test conditions, No minimum recovery time is
required.
5 Apparatus
5.1 Method A: Direct view optical microscopy
This method utilizes a light an optical microscope in which a primary objective lens forms a first
image that is then magnified by an eyepiece that projects the image directly to the user’s eye. It
shall have the following features and capabilities:
 a suitable ferrule or connector adapter;
 a light source and focusing mechanism;
 a means to measure defects observed in the image a built-in laser safety filter.
Laser safety is of particular concern when using direct view microscopes, as any energy in the
optical path is directed into the eye of the observer. If Method A is used the user shall ensure
there is no laser active on the link prior to inspection. See IEC 60825-2 for laser safety of
optical fibre communication systems.

5.2 Method B: Video microscopy

This method utilizes a light an optical microscope in which a lens system forms an image on a

sensor that, in turn, transfers the image to a display. The user views the image on the display.

It shall have the following features and capabilities:

• a suitable ferrule or connector adapter;

• a light source and focusing mechanism;

• a means to measure defects surface anomalies observed in the image.

5.3 Method C: Automated analysis microscopy

This method utilizes a light an optical microscope in which a digital image is acquired or
created and subsequently analysed via an algorithmic process. The purpose of such a system
is to reduce the effects of human subjectivity in the analysis process and, in some cases, to
improve cycle times. It shall have the following features and capabilities:
• a suitable ferrule or connector adapter;
• a means for acquiring or creating a digital image;
• algorithmic analysis of the digital image;
• a means to compare the analysed image to programmable acceptance criteria in such a
manner that a result of “pass” or “fail” is provided.
5.4 Calibration Certification requirements for low and high resolution systems
5.4.1 General
Microscope systems for Methods A, B and C shall be calibrated certified for use in either low or
high resolution applications. It is suggested that this calibration This certification shall be
conducted with a purpose-built calibration certification artefact that can serve to validate a
system’s ability to detect defects surface anomalies of relevant size. Such an artefact shall be
provided with instructions on its use and shall be manufactured in a method such that it can be
measured in a traceable manner. Details of the manufacture of such artefacts can be found in
Annex B.
For reference, a system’s optical resolution may be calculated using the formula below. Optical
resolution is not equivalent to the system’s detection capability. In most cases, the system will
be able to detect defects smaller than its optical resolution.
Optical resolution = (0,61 × wavelength of illumination source) / system’s numerical aperture
5.4.2 Requirement for low resolution microscope systems
This requirement is a minimum total magnification offering a field of view (FOV) of at least
250 µm (for Methods B and C, this dimension is to shall be measured in the vertical, or most
constrained, axis) capable of detecting low-contrast defects of 2 µm in diameter or width.
5.4.3 Requirements for high resolution microscope systems
These requirements are a minimum total magnification offering a field of view of at least
120 µm (for Methods B and C, this dimension shall be measured in the vertical, or most
constrained, axis) capable of detecting low contrast scratches of 0,2 µm in width and 0,003 µm
in depth scratches 1 µm in width. A system with FOV less than 250 µm will require
scrolling/panning of the end face or subsequent inspection with a larger FOV system to meet
the full requirements of this standard.

– 10 – IEC 61300-3-35:2015 RLV © IEC 2015

6 Procedure
6.1 Measurement regions
For the purposes of setting requirements on endface quality, the polished endface of a

connector is divided into measurement regions defined as follows (see Table 1 and Table 2).

Table 1 – Measurement regions for single fibre connectors

Zone Diameter for single mode Diameter for multimode

A: core 0 µm to 25 µm 0 µm to 65 µm
B: cladding 25 µm to 120 µm 65 µm to 120 µm
C: adhesive
120 µm to 130 µm 120 µm to 130 µm
D: contact 130 µm to 250 µm 130 µm to 250 µm
NOTE 1 All data above assumes a 125 µm cladding diameter.
NOTE 2 Multimode core zone diameter is set at 65 µm to accommodate all
common core sizes in a practical manner.
NOTE 3 A defect is defined as existing entirely within the inner-most zone
which it touches.
Table 2 – Measurement regions for multiple fibre rectangular ferruled connectors
Zone Diameter for single mode Diameter for multimode
A: Core 0 µm to 25 µm 0 µm to 65 µm
B: Cladding
25 µm to 115 µm 65 µm to 115 µm
NOTE 1 All data above assumes a 125 µm cladding diameter.
NOTE 2 Multimode core zone diameter is set at 65 µm to accommodate all
common core sizes in a practical manner.
NOTE 3 A defect is defined as existing entirely within the inner-most zone which
it touches.
NOTE 4 Criteria should be applied to all fibres in the array for functionality of
any fibres in the array.
6.1 Calibration Certification procedure

On commissioning, and periodically during its life, the microscope system shall be calibrated
certified.
Fix the artefact(s) on the microscope system and focus the image.
Follow the manufacturer’s instructions on how to calibrate certify the system using the artefact.
Generally, this should entail viewing the artefact and verifying that the small features and
contrast targets are “reliably detectable”; and that the region of interest can be fully viewed or
scanned. Reliably detectable is defined as sufficient clear and visible so that a typical
technician of average training would recognize the feature at least 98 % of the time.
For automated systems, software utilities to perform this calibration certification shall be
provided. In any event, these systems shall be able to perform the same calibration certification
so as to validate the fact that they can reliably detect the features of the artefact.

6.2 Inspection procedure
It is recommended that the complete ferrule end face be inspected for cleanliness and absence

of loose debris. This is especially important for rectangular ferrules such as MT ferrules. Use of

inspection equipment with large FOV of and oblique illumination eases the detection of loose

particles. This inspection for cleanliness should take place prior the inspection of the polished
end faces.
Figure 1 shows a flowchart which describes the following procedure which shall be employed.

• Focus the microscope so that a crisp image can be seen.

• Align the inspection zones prescribed within the inspection criteria with the outer edge of
the optical fibre.
• Locate all defects and scratches within the zones prescribed in the acceptance criteria as
specified in the relevant Tables of 6.3. Count and measure defects and count scratches
within each zone. Exclude from analysis all defects contained within the zone covering the
interface between fibre and ferrule (Zone C: adhesive). In the context of this standard,
“none” means no scratch or defect detectible by the qualified inspection system.
• Once all defects and scratches have been quantified, the results should be totalled by zone
and compared with the appropriate acceptance criteria (see Tables 1 to 4). Such criteria
can be found in 5.4. If a defect is found to be in more than one zone, apply the
scratch/defect to the most stringent zone and exclude from further analysis.
• Any end face with quantified defects or scratches in excess of the values shown in any
given zone on the table is determined to have failed. Scratches that are extremely wide
may be judged to be too large, per the acceptance criteria and result in immediate failure
of the device under test (DUT).
• If the fibre end face fails inspection for defects, the user shall clean the fibre end face and
repeat the inspection process. Several attempts at cleaning may be required. Consult
IEC TR 62627-01 for recommendations on cleaning methods.

In this way, loose debris can be removed and the fibre may be able to pass a subsequent
inspection without rework or scrap. Cleaning shall be repeated a number of times consistent
with the cleaning procedure being used.

– 12 – IEC 61300-3-35:2015 RLV © IEC 2015

Begin
Quantify
scratches and
defects
Meets
No
ac ceptance
criteria?
No
Fail for
Fail for
scratches?
defects
Yes
Clean fibre
end face
Yes
Quantify
scratches
and defects
No Yes
Decrease
defects?
DUT fails
DUT passes
End
IEC
Figure 1 – Inspection procedure flow
6.3 Visual requirements
It is not the intention of this standard that the size of scratches shall be measured, the
dimensions and requirements are selected such that they can be estimated. There is no need
to measure for example if a scratch is 2,3 µm wide.

Visual requirements for each single-mode and multi-mode connectors are shown in Table 3,
Table 4, Table 5 and Table 6 Table 1 to Table 4.

Table 3 1 – Visual requirements for single mode PC polished connectors,

single mode fibre, RL ≥ 45 dB
a
Zone name Scratches Defects
(maximum number (maximum number
of a given dimension) of a given dimension)

A: core
None None
0 µm to 25 µm
No limit < 2 µm
B: cladding
No limit ≤ 3 µm
5 from 2 µm to 5 µm
None > 3 µm
25 µm to 115 µm
None > 5 µm
C: adhesive
No limit No limit
115 µm to 135 µm
D: contact
No limit
None > 10 µm
135 µm to 250 µm
NOTE 1 For scratches, the requirement refers to width.
NOTE 2 No visible subsurface cracks are allowed in the core or cladding zones.
NOTE 3 All loose particles should be removed. If defect(s) are non-removable, it should be within the criteria
above to be acceptable for use.
NOTE 4 1 There are no requirements for the area outside the contact zone since defects in this area have no
influence on the performance. Cleaning loose debris beyond this region is recommended good practice. This is
of particular concern for multiple-fibre rectangular-ferrule connectors.
NOTE 5 Structural features that are part of the functional design of the optical fibre, such as microstructures,
are not considered defects.
NOTE 2 For multiple-fibre rectangular-ferrule connectors, the criteria apply to all fibres in the array.

a
For multiple-fibre rectangular-ferrule connectors only the requirements of Zone A and Zone B apply.

Table 4 2 – Visual requirements for single mode angle polished connectors (APC), single
mode fibre
a
Zone name Scratches Defects
(maximum number (maximum number
of a given dimension) of a given dimension)
A: core
None
≤4 4 ≤ 3 µm
0 µm to 25 µm
No limit < 2 µm
B: cladding
No limit 5 from 2 µm to 5 µm
25 µm to 115 µm
None > 5 µm
C: adhesive
No limit No limit
115 µm to 135 µm
D: contact
No limit
None > 10 µm
135 µm to 250 µm
NOTE 1 For scratches, the requirement refers to width.
NOTE 2 No visible subsurface cracks are allowed in the core or cladding zones.
NOTE 3 All loose particles should be removed. If defect(s) are non-removable, it should be within the criteria
above to be acceptable for use.
NOTE 4 1 There are no requirements for the area outside the contact zone since defects in this area have no
influence on the performance. Cleaning loose debris beyond this region is recommended good practice. This is
of particular concern for multiple-fibre rectangular-ferrule connectors.
NOTE 5 Structural features that are part of the functional design of the optical fibre, such as microstructures,
are not considered defects.
NOTE 2 For multiple-fibre rectangular-ferrule connectors, the criteria apply to all fibres in the array.

a
For multiple-fibre rectangular-ferrule connectors, only the requirements of Zone A and Zone B apply.

– 14 – IEC 61300-3-35:2015 RLV © IEC 2015

Table 5 3 – Visual requirements for single-mode PC polished connectors, single mode
fibre, RL ≥ 26 dB and single-mode transceivers using a fibre-stub interface

a
Zone Scratches Defects
(maximum number (maximum number
of a given dimension) of a given dimension)

A: core
2 ≤ 3 µm
None
None > 3 µm
0 µm to 15 µm
No limit < 5 µm
B: cladding
No limit ≤ 3 µm
5 from 5 µm to 10 µm
3 > 3 µm
15 µm to 115 µm
None > 10 µm
C: adhesive
No limit No limit
115 µm to 135 µm
No limit < 20 µm
D: contact
No limit
5 from 20 µm to 30 µm
135 µm to 250 µm
None > 30 µm
NOTE 1 For scratches, the requirement refers to width.
NOTE 2 No visible subsurface cracks are allowed in the core or cladding zones.
NOTE 3 All loose particles should be removed. If defect(s) are non-removable, it should be within the criteria
above to be acceptable for use.
NOTE 4 1 There are no requirements for the area outside the contact zone since defects in this area have no
influence on the performance. Cleaning loose debris beyond this region is recommended good practice. This is
of particular concern for multiple-fibre rectangular-ferrule connectors.
NOTE 5 Criteria should be applied to all fibre pairs in the array for functionality of any fibre pairs in the array.
NOTE 6 Structural features that are part of the functional design of the optical fibre, such as microstructures,
are not considered defects.
NOTE 2 For multiple-fibre rectangular-ferrule connectors, the criteria apply to all fibres in the array.

a
For multiple-fibre rectangular-ferrule connectors, only the requirements of Zone A and Zone B apply.

Table 6 4 – Visual requirements for multi-mode PC polished

connectors, multimode fibres
a
Zone Scratches Defects
(maximum number (maximum number
of a given dimension) of a given dimension)

A: core
No limit ≤ 3 µm
4 ≤ 5 µm
None > 5 µm
0 µm to 65 µm
0 None > 3 µm
No limit < 2 5 µm
B: cladding
No limit ≤ 5 µm
5 from 2 5 µm to 5 10 µm
65 µm to 115 µm
0 None > 5 µm
None > 5 10 µm
C: adhesive
No limit No limit
115 µm to 135 µm
No limit < 20 µm
D: contact
No limit
5 from 20 µm to 30 µm
135 µm to 250 µm
None > 10 30 µm
NOTE 1 For scratches, the requirement refers to width.
NOTE 2 No visible subsurface cracks are allowed in the core or cladding zones.
NOTE 3 All loose particles should be removed. If defect(s) are non-removable, it should be within the criteria
above to be acceptable for use.
NOTE 4 1 There are no requirements for the area outside the contact zone since defects in this area have no
influence on the performance. Cleaning loose debris beyond this region is recommended good practice. This is
of particular concern for multiple-fibre rectangular-ferrule connectors.
NOTE 2 For multiple-fibre rectangular-ferrule connectors, the criteria apply to all fibres in the array.
NOTE 5 3 The zone size for multi-mode fibres has been set at 65 µm to accommodate both 50 µm and 62,5 µm
core size fibres. This is done to simplify the grading process.
NOTE 6 Structural features that are part of the functional design of the optical fiber, such as microstructures,
are not considered defects.
a
For multiple-fibre rectangular-ferrule connectors only, the requirements of Zone A and Zone B apply.

– 16 – IEC 61300-3-35:2015 RLV © IEC 2015

Annex A
(informative)
Examples of inspected end faces with defects surface anomalies

In Figures A.1 to A.10, the images on the left are with a computer overlay highlighting where

the scratch or defect was found, and the images on the right are without the overlay.

Examples of low resolution graded images:

Image 1
Fibre/connector type: SM, RL ≥ 45 dB (Table 3).
Result: rejected.
Reason: 3 defects in the cladding zone. Those highlighted in red are over 5 µm in diameter
and a failure condition per Table 3.

Image 2
Fibre/connector type: SM, RL ≥ 45 dB (Table 3).
Result: rejected.
Reason: 1 defect touching the core zone. Per Table 1, since it touches the core zone, it is
judged to exist entirely in the core zone. Per Table 3, no defects are allowed in the core zone.

Image 3
Fibre/connector type: SM, RL ≥ 45 dB (Table 3)
Result: accepted.
Reason: 1 fine scratch and 2 particles < 5 µm in the cladding zone. Per Table 3, acceptable.

Image 4
Fibre/connector type: SM, RL ≥ 45 dB (Table 3).
Result: accepted.
Reason: observed defects: 6 defects in the cladding zone. One defect is < 2 µm and can be
ignored; the other 5 are below 5 µm in diameter. In the contact zone, 1 defect < 10 µm. Per
Table 3, acceptable.
– 18 – IEC 61300-3-35:2015 RLV © IEC 2015

Image 5
Fibre/connector type: MM, (Table 6).
Result: accepted.
Reason: 2 defects < 5 µm in the cladding zone (1 defect of 4,8 µm and 1 defect of 4,9 µm); 1
defect in the contact zone. Per Table 6; acceptable.

Image 6
Fibre/connector type: MM (Table 6).
Result: rejected.
Reason: 3 defects in the core zone, 1 of which measures 6,0µm (highlighted in red); 7 defects
in the cladding zone, 1 of which measures 7,0 µm. Both red particles exceed thresholds
established in Table 6.
Examples of high resolution graded images:

Image 7
Fibre/connector type: SM, RL ≥ 45 dB (Table 3).
Result: rejected.
Reason: 1 scratch in the core zone (highlighted in red, failure), 2 small defects in the cladding
zone that are both < 2 µm and can be ignored. Several small defects in the adhesive zone.

Image 8
Fibre/connector type: SM, RL ≥ 45 dB (Table 3).
Result: accepted.
Reason: several defects < 2 µm which can be ignored, 3 scratches in the cladding zone.

– 20 – IEC 61300-3-35:2015 RLV © IEC 2015

Image 9
Fibre/connector type: SM, RL ≥ 45 dB (Table 3).
Result: accepted.
Reason: multiple defects in the cladding zone that are <2 µm and can be ignored (per
procedure in this standard, assumes cleaning attempts did not remove and these are fixed
particles). 2 defects in the cladding zone that are <5 µm diameter. 1 scratch in the cladding
zone.
Image 10
Fibre/connector type: MM (Table 6).
Result: accepted.
Reason: 1 fine scratch (less than 2 µm wide), and 2 defects <5 µm in core zone; 2 fine
scratches and 4 defects <5 µm in the cladding zone; multiple defects in the contact zone that
fall below the 10 µm failure threshold, per Table 6.

Image 11
Fibre/connector type: MM (Table 6).
Result: rejected.
Reason: one particle >5 µm diameter in the cladding zone produced failure. Other observed
defects that did not create a failure condition: 1 fine scratch (<2 µm wide) and 1 defect <5 µm
(2,6 µm) in the core zone; 3 fine scratches, 3 defects <5 µm in the cladding zone.

– 22 – IEC 61300-3-35:2015 RLV © IEC 2015

IEC
Figure A.1 – Example 1 (low resolution system)
IEC
Figure A.2 – Example 1 (high resolution system)
Test requirements: Single-mode PC polished connectors, RL ≥ 45 dB (see Table 1).
Result: Rejected.
Reason: 1 defect (highlighted in red) in Zone B (cladding). This defect is larger
than 5 µm, which is a failure condition as per Table 1.

IEC
Figure A.3 – Example 2 (low resolution system)

IEC
Figure A.4 – Example 2 (high resolution system)
Test requirements: Single-mode angle polished (APC) connectors (see Table 2).
Result: Rejected.
Reason: 1 defect (highlighted in red) touching Zone A (core). As per Table 2,
since it touches Zone A, it is judged to exist entirely in Zone A. Per
Table 2, no defects are allowed
...