oSIST prEN IEC 60793-1-45:2023
(Main)Optical fibres - Part 1-45: Measurement methods and test procedures - Mode field diameter
Optical fibres - Part 1-45: Measurement methods and test procedures - Mode field diameter
Lichtwellenleiter - Teil 1-45: Messmethoden und Prüfverfahren - Modenfelddurchmesser
Fibres optiques - Partie 1-45 : Méthodes de mesure et procédures d'essai - Diamètre du champ de mode
Optična vlakna - 1-45. del: Merilne metode in postopki preskušanja - Premer osnovnega rodu
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN IEC 60793-1-45:2023
01-junij-2023
Optična vlakna - 1-45. del: Merilne metode in postopki preskušanja - Premer polja
načina
Optical fibres - Part 1-45: Measurement methods and test procedures - Mode field
diameter
Lichtwellenleiter - Teil 1-45: Messmethoden und Prüfverfahren - Modenfelddurchmesser
Fibres optiques - Partie 1-45 : Méthodes de mesure et procédures d'essai - Diamètre du
champ de mode
Ta slovenski standard je istoveten z: prEN IEC 60793-1-45:2023
ICS:
33.180.10 (Optična) vlakna in kabli Fibres and cables
oSIST prEN IEC 60793-1-45:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN IEC 60793-1-45:2023
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oSIST prEN IEC 60793-1-45:2023
86A/2300/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60793-1-45 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-03-31 2023-06-23
SUPERSEDES DOCUMENTS:
86A/2219/CD, 86A/2241A/CC
IEC SC 86A : FIBRES AND CABLES
SECRETARIAT: SECRETARY:
France Mr Laurent Gasca
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
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• any relevant patent rights of which they are aware and to provide supporting documentation,
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AC/22/2007.
TITLE:
Optical fibres - Part 1-45: Measurement methods and test procedures - Mode field diameter
PROPOSED STABILITY DATE: 2027
NOTE FROM TC/SC OFFICERS:
Copyright © 2023 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to
download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National
Committee positions. You may not copy or "mirror" the file or printed version of the document, or any part of it, for
any other purpose without permission in writing from IEC.
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oSIST prEN IEC 60793-1-45:2023
IEC 60793-1-45/Ed3 © IEC 2023 – 2 – 86A/2300/CDV
1 CONTENTS
2 FOREWORD . 5
3 1 Scope . 7
4 2 Normative references . 7
5 3 Terms and definitions . 7
6 4 General consideration about mode field diameter . 7
7 5 Reference test method . 8
8 6 Apparatus . 8
9 6.1 General . 8
10 6.2 Light source . 8
11 6.3 Input optics . 9
12 6.4 Input positioner . 9
13 6.5 Cladding mode stripper . 9
14 6.6 High-order mode filter . 9
15 6.7 Output positioner . 9
16 6.8 Output optics . 9
17 6.9 Detector . 9
18 6.10 Computer . 9
19 7 Sampling and specimens . 10
20 7.1 Specimen length . 10
21 7.2 Specimen end face . 10
22 8 Procedure . 10
23 9 Calculations . 10
24 9.1 Basic equations . 10
25 9.2 Method A – Direct far-field scan . 10
26 9.3 Method B – Variable aperture in the far field . 11
27 9.4 Method C – Near-field scan . 12
28 10 Results . 12
29 10.1 Information available with each measurement . 12
30 10.2 Information available upon request . 12
31 11 Specification information . 13
32 Annex A (normative) Requirements specific to method A – Mode field diameter by
33 direct far-field scan . 14
34 A.1 Apparatus . 14
35 A.1.1 General . 14
36 A.1.2 Scanning detector assembly – Signal detection electronics . 14
37 A.1.3 Computer. 15
38 A.2 Procedure . 15
39 A.3 Calculations . 15
40 A.3.1 Determine folded power curve . 15
41 A.3.2 Compute the top (T) and bottom (B) integrals of Equation (1) . 15
42 A.3.3 Complete the calculation . 16
43 A.4 Sample data . 16
44 Annex B (normative) Requirements specific to method B – Mode field diameter by
45 variable aperture in the far field . 17
46 B.1 Apparatus . 17
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47 B.1.1 General . 17
48 B.1.2 Output variable aperture assembly . 17
49 B.1.3 Output optics system . 18
50 B.1.4 Detector assembly and signal detection electronics . 18
51 B.2 Procedure . 18
52 B.3 Calculations . 18
53 B.3.1 Determine complementary aperture function . 18
54 B.3.2 Complete the integration . 19
55 B.3.3 Complete the calculation . 19
56 B.4 Sample data . 19
57 Annex C (normative) Requirements specific to method C – Mode field diameter by
58 near-field scan . 20
59 C.1 Apparatus . 20
60 C.1.1 General . 20
61 C.1.2 Magnifying output optics . 20
62 C.1.3 Scanning detector . 20
63 C.1.4 Detection electronics . 21
64 C.2 Procedure . 21
65 C.3 Calculations . 21
66 C.3.1 Calculate the centroid . 21
67 C.3.2 Fold the intensity profile . 22
68 C.3.3 Compute the integrals . 22
69 C.3.4 Complete the calculation . 22
70 C.4 Sample data . 23
71 Annex D (normative) Requirements specific to method D – Mode field diameter by
72 optical time domain reflectometer (OTDR) . 24
73 D.1 General . 24
74 D.2 Apparatus . 24
75 D.2.1 OTDR . 24
76 D.2.2 Optional auxiliary switches . 24
77 D.2.3 Optional computer . 25
78 D.2.4 Test sample . 25
79 D.2.5 Reference sample . 25
80 D.3 Procedure . 25
81 D.3.1 Orientation and notation . 25
82 D.4 Calculations . 26
83 D.4.1 Reference fibre mode field diameter . 26
84 D.4.2 Computation of the specimen mode field diameter . 27
85 D.4.3 Validation . 27
86 Annex E (informative) Sample data sets and calculated values . 29
87 E.1 General . 29
88 E.2 Method A – Mode field diameter by direct far-field scan . 29
89 E.3 Method B – Mode field diameter by variable aperture in the far field . 30
90 E.4 Method C – Mode field diameter by near-field scan . 30
91
92 Figure 1 – Transform relationships between measurement results . 8
93 Figure A.1 – Far-field measurement set . 14
94 Figure B.1 – Variable aperture by far-field measurement set . 17
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95 Figure C.1 – Near-field measurement set-ups . 20
96 Figure D.1 – Optical switch arrangement . 25
97 Figure D.2 – View from reference fibre A . 26
98 Figure D.3 – View from reference fibre B . 26
99 Figure D.4 – Validation example – Comparison of methods . 27
100
101 Table E.1 – Sample data, method A – Mode field diameter by direct far-field scan . 29
102 Table E.2 – Sample data set, method B – Mode field diameter by variable aperture in
103 the far field . 30
104 Table E.3 – Sample data set, method C – Mode field diameter by near-field scan . 30
105
106
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IEC 60793-1-45/Ed3 © IEC 2023 – 5 – 86A/2300/CDV
107 INTERNATIONAL ELECTROTECHNICAL COMMISSION
108 ____________
109
110 OPTICAL FIBRES –
111 Part 1-45: Measurement methods and test procedures –
112 Mode field diameter
113
114
115 FOREWORD
116 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
117 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
118 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
119 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
120 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
121 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
122 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
123 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
124 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
125 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
126 consensus of opinion on the relevant subjects since each technical committee has representation from all
127 interested IEC National Committees.
128 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
129 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
130 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
131 misinterpretation by any end user.
132 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
133 transparently to the maximum extent possible in their national and regional publications. Any divergence between
134 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
135 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
136 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
137 services carried out by independent certification bodies.
138 6) All users should ensure that they have the latest edition of this publication.
139 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
140 members of its technical committees and IEC National Committees for any personal injury, property damage or
141 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
142 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
143 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
144 indispensable for the correct application of this publication.
145 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
146 rights. IEC shall not be held responsible for identifying any or all such patent rights.
147 International Standard IEC 60793-1-45 has been prepared by subcommittee 86A: Fibres and
148 cables, of IEC technical committee 86: Fibre optics.
149 This third edition cancels and replaces the second edition published in 2017. This edition
150 constitutes a technical revision.
151 This edition includes the following significant technical changes with respect to the previous
152 edition:
153 a) Modification of the minimum distance between the fiber end and the detector for the direct
154 far field scan (Annex A).
155 b) Generalization of the requirement for the minimum dynamic range for all fibre types (Annex
156 A).
157
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oSIST prEN IEC 60793-1-45:2023
IEC 60793-1-45/Ed3 © IEC 2023 – 6 – 86A/2300/CDV
158 The text of this International Standard is based on the following documents:
CDV Report on voting
86A/1758/CDV 86A/1802/RVC
159
160 Full information on the voting for the approval of this International Standard can be found in the
161 report on voting indicated in the above table.
162 This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
163 A list of all parts in the IEC 60793 series, published under the general title Optical fibres, can
164 be found on the IEC website.
165 The committee has decided that the contents of this document will remain unchanged until the
166 stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
167 the specific document. At this date, the document will be
168 • reconfirmed,
169 • withdrawn,
170 • replaced by a revised edition, or
171 • amended.
172
173
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174 OPTICAL FIBRES –
175
176 Part 1-45: Measurement methods and test procedures –
177 Mode field diameter
178
179
180
181 1 Scope
182 This part of IEC 60793 establishes uniform requirements for measuring the mode field diameter
183 (MFD) of single-mode optical fibre, thereby assisting in the inspection of fibres and cables for
184 commercial purposes.
185 2 Normative references
186 The following documents are referred to in the text in such a way that some or all of their content
187 constitutes requirements of this document. For dated references, only the edition cited applies.
188 For undated references, the latest edition of the referenced document (including any
189 amendments) applies.
190 IEC 60793-1-40:2001, Optical fibres – Part 1-40: Measurement methods and test procedures –
191 Attenuation
192 IEC 60793-2, Optical fibres – Part 2: Product specifications – General
193 3 Terms and definitions
194 No terms and definitions are listed in this document.
195 ISO and IEC maintain terminological databases for use in standardization at the following
196 addresses:
197 • IEC Electropedia: available at http://www.electropedia.org/
198 • ISO Online browsing platform: available at http://www.iso.org/obp
199 4 General consideration about mode field diameter
200 The mode field diameter measurement represents a measure of the transverse extent of the
201 electromagnetic field intensity of the guided mode in a fibre cross section, and it is defined from
202 the far-field intensity distribution as a ratio of integrals known as the Petermann II definition.
203 See Equation (1).
204 The definitions of mode field diameter are strictly related to the measurement configurations.
205 The mathematical equivalence of these definitions results from transform relationships between
206 measurement results obtained by different implementations summarized in Figure 1 as follows.
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Far-field
scan
Hankel
Integration
transform
Variable
Near-field
aperture
scan
technique
IEC
207
208 Figure 1 – Transform relationships between measurement results
209 Four methods are described for measuring mode field diameter:
210 – method A: direct far-field scan;
211 – method B: variable aperture in the far field;
212 – method C: near-field scan;
213 – method D: bi-directional backscatter using an optical time domain reflectometer (OTDR).
214 All four methods apply to all categories of type B single-mode fibre shown in IEC 60793-2 and
215 operating near 1 310 nm or 1 550 nm. Method D is not recommended for the measurement of
216 fibres of unknown type or design.
217 Information common to all four methods is contained in Clauses 1 to 11, and information
218 pertaining to each individual method appears in annexes A, B, C and D, respectively.
219 5 Reference test method
220 Method A, direct far-field scan, is the reference test method (RTM), which shall be the one used
221 to settle disputes.
222 6 Apparatus
223 6.1 General
224 The following apparatus is common to all measurement methods. Annexes A, B, C and D include
225 layout drawings and other equipment requirements for each of the four methods, respectively.
226 6.2 Light source
227 For methods A, B and C, use a suitable coherent or non-coherent light source, such as a
228 semiconductor laser or a sufficiently powerful filtered white light source. The source shall
229 produce sufficient radiation at the intended wavelength(s) and be stable in intensity over a time
230 period sufficient to perform the measurement.
231 A monochromator or interference filter(s) may be used, if required, for wavelength selection.
232 The detail specification shall specify the wavelength of the source. The full width half maximum
233 (FWHM) spectral line width of the source shall be less than or equal to 10 nm, unless otherwise
234 specified.
235 See Annex D for method D.
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236 6.3 Input optics
237 For method A, B, and C, an optical lens system or fibre pigtail may be employed to excite the
238 specimen. It is recommended that the power coupled into the specimen be relatively insensitive
239 to the position of its input end face. This can be accomplished by using a launch beam that
240 spatially and angularly overfills the input end face.
241 If using a butt splice, employ index-matching material between the fibre pigtail and the specimen
242 to avoid interference effects. The coupling shall be stable for the duration of the measurement.
243 See Annex D for method D.
244 6.4 Input positioner
245 Provide means of positioning the input end of the specimen to the light source. Examples
246 include the use of x-y-z micropositioner stages, or mechanical coupling devices such as
247 connectors, vacuum splices, three-rod splices. The position of the fibre shall remain stable over
248 the duration of the measurement.
249 6.5 Cladding mode stripper
250 Use a device that extracts cladding modes. Under some circumstances, the fibre coating will
251 perform this function.
252 6.6 High-order mode filter
253 Use a means to remove high-order propagating modes in the wavelength range that is greater
254 than or equal to the cut-off wavelength of the specimen. For example, a one-turn bend with a
255 radius of 30 mm on the fibre is generally sufficient for most B-652, B-653, B-654, B-655, B-656
256 and B-657 fibres. For some B-657 fibres, smaller radius, multiple bends or longer specimen
257 length can be applied to remove high-order propagating modes.
258 6.7 Output positioner
259 Provide a suitable means for aligning the fibre output end face in order to allow an accurate
260 axial adjustment of the output end, such that, at the measurement wavelength, the scan pattern
261 is suitably focused on the plane of the scanning detector. Such coupling may include the use
262 of lenses, or may be a mechanical connector to a detector pigtail.
263 Provide means such as a side-viewing microscope or camera with a crosshair to locate the fibre
264 at a fixed distance from the apertures or detectors. It may be sufficient to provide only
265 longitudinal adjustment if the fibre is constrained in the lateral plane by a device such as a
266 vacuum chuck (this depends mainly upon the size of the light detector).
267 6.8 Output optics
268 See the appropriate annex: A, B, C or D.
269 6.9 Detector
270 See the appropriate annex: A, B, C or D.
271 6.10 Computer
272 Use a computer to perform operations such as controlling the apparatus, taking intensity
273 measurements, and processing the data to obtain the final results. For individual details, see
274 the appropriate annex: A, B, C or D.
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275 7 Sampling and specimens
276 7.1 Specimen length
277 For methods A, B and C, the specimen shall be a known length, typically 2 m ± 0,2 m for most
278 B-652, B-653, B-654, B-655, B-656 and B-657 fibres. For some B-657 fibres, longer specimen
279 length can be used to avoid high-order propagating modes, 22 m for example.
280 For method D, OTDR, the sample shall be long enough to exceed (or be positioned beyond)
281 the dead zone of the OTDR, with both ends accessible, as described in the backscatter test
282 method IEC 60793-1-40.
283 7.2 Specimen end face
284 Prepare a flat end face, orthogonal to the fibre axis, at the input and output ends of each
285 specimen.
286 8 Procedure
287 See Annexes A, B, C and D for methods A, B, C and D, respectively.
288 9 Calculations
289 9.1 Basic equations
290 The basic equations for calculating mode field diameter by methods A, B and C are given below.
291 For additional calculations, see the appropriate annex: A, B, C or D. Sample data sets for
292 methods A, B and C are included in Annex E.
293 9.2 Method A – Direct far-field scan
294 The following equation defines the mode field diameter for method A in terms of the
295 electromagnetic field emitted from the end of the specimen.
296 Calculate the mode field diameter by scanning the far-field data and evaluating the Petermann
297 II integral, which is defined from the far-field intensity distribution:
1/ 2
π / 2
P(θ)sin(θ)cos(θ)dθ
F
λ 2 ∫
0
298 2W = (1)
0
π / 2
π 3
P(θ)sin (θ)cos(θ)dθ
F
∫
0
299 where
300 2W is the mode field diameter in µm;
0
301 P (θ) is the far-field intensity distribution;
F
302 λ is the wavelength of measurement in µm;
303 θ is the angle in the far-field measurement from the
...
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