SIST EN 60793-1-44:2004
(Main)Optical fibres -- Part 1-44: Measurement methods and test procedures - Cut-off wavelength
Optical fibres -- Part 1-44: Measurement methods and test procedures - Cut-off wavelength
Provides methods for measuring the cut-off wavelength of single-mode optical fibres. The test method applies to a sample fibre in either an uncabled condition, or in a cable, or as a jumper cable. All methods require a reference measurement, with either a bend-reference technique or a multimode-reference technique.
Lichtwellenleiter -- Teil 1-44: Messmethoden und Prüfverfahren - Grenzwellenlänge
Fibres optiques -- Partie 1-44: Méthodes de mesure et procédures d'essai - Longueur d'onde de coupure
Définit les méthodes de mesure de la longueur d'onde de coupure des fibres optiques unimodales. La méthode d'essai décrit les procédures pour un échantillon de fibre soit à l'état non câblée, soit dans un câble, soit en câble jarretière. Toutes les méthodes prescrivent une mesure de référence, soit la technique de la fibre de référence courbée, soit la technique de la fibre de référence multimodale.
Optična vlakna – 1-44. del: Metode merjenja in predkusni postopki - Mejna valovna dolžina (IEC 60793-1-44:2001)*
General Information
Relations
Standards Content (Sample)
SLOVENSKI SIST EN 60793-1-44:2004
STANDARD
september 2004
Optična vlakna – 1-44. del: Metode merjenja in predkusni postopki - Mejna
valovna dolžina (IEC 60793-1-44:2001)*
Optical fibres - Part 1-44: Measurement methods and test procedures - Cut-off
wavelength (IEC 60793-1-44:2001)
ICS 33.180.10 Referenčna številka
SIST EN 60793-1-44:2004(en)
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
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EUROPEAN STANDARD EN 60793-1-44
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2002
ICS 33.180.10 Partly supersedes EN 188000:1992
English version
Optical fibres
Part 1-44: Measurement methods and test procedures –
Cut-off wavelength
(IEC 60793-1-44:2001)
Fibres optiques Lichtwellenleiter
Partie 1-44: Méthodes de mesure Teil 1-44: Messmethoden
et procédures d'essai – und Prüfverfahren –
Longueur d'onde de coupure Grenzwellenlänge
(CEI 60793-1-44:2001) (IEC 60793-1-44:2001)
This European Standard was approved by CENELEC on 2001-10-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60793-1-44:2002 E
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EN 60793-1-44:2002 - 2 -
Foreword
The text of document 86A/673/FDIS, future edition 1 of IEC 60793-1-44, prepared by SC 86A, Fibres
and cables, of IEC TC 86, Fibre optics, was submitted to the IEC-CENELEC parallel vote and was
approved by CENELEC as EN 60793-1-44 on 2001-10-01.
This European Standard supersedes subclause 4.21 (test method 312) and subclause 4.22 (test
method 313) of EN 188000:1992.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2002-09-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2004-10-01
Annexes designated "normative" are part of the body of the standard.
In this standard, annexes A, B, C and D are normative.
Compared to IEC 60793-1:1989 and IEC 60793-2:1992, IEC/SC 86A has adopted a revised structure
of the new IEC 60793 series: The individual measurement methods and test procedures for optical
fibres are published as "Part 1-XX"; the product standards are published as "Part 2-XX".
The general relationship between the new series of EN 60793 and the superseded European
Standards of the EN 188000 series is as follows:
EN Title supersedes
EN 60793-1-XX Optical fibres -- Part 1-XX: Measurement methods Individual subclauses of
and test procedures EN 188000:1992
EN 60793-2-XX Optical fibres -- Part 2-XX: Product specifications EN 188100:1995
EN 188101:1995
EN 188102:1995
EN 188200:1995
EN 188201:1995
EN 188202:1995
EN 60793-1-4X consists of the following parts, under the general title: Optical fibres:
- Part 1-40: Measurement methods and test procedures – Attenuation
- 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
- Part 1-44: Measurement methods and test procedures – Cut-off wavelength
- Part 1-45: Measurement methods and test procedures – Mode field diameter
- 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 1-48: Measurement methods and test procedures – Under consideration
- Part 1-49: Measurement methods and test procedures – Under consideration
__________
Endorsement notice
The text of the International Standard IEC 60793-1-44:2001 was approved by CENELEC as a European
Standard without any modification.
__________
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NORME CEI
INTERNATIONALE IEC
60793-1-44
INTERNATIONAL
Première édition
STANDARD
First edition
2001-07
Fibres optiques –
Partie 1-44:
Méthodes de mesure et procédures d'essai –
Longueur d'onde de coupure
Optical fibres –
Part 1-44:
Measurement methods and test procedures –
Cut-off wavelength
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Pour prix, voir catalogue en vigueur
For price, see current catalogue
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60793-1-44 © IEC:2001 – 3 –
CONTENTS
FOREWORD.5
INTRODUCTION.9
1 Scope.11
2 Normative references.11
3 Background .11
4 Overview of methods .13
5 Mapping functions.15
6 Reference test method.15
7 Apparatus.15
7.1 Light source.15
7.2 Modulation.15
7.3 Launch optics .15
7.4 Support and positioning apparatus .17
7.5 Cladding mode stripper.17
7.6 Deployment mandrel.17
7.7 Detection optics.17
7.8 Detector assembly and signal detection electronics.19
8 Sampling and specimens .23
8.1 Specimen length.23
8.2 Specimen end face .23
9 Procedure.23
9.1 Position specimen in apparatus.23
9.2 Measure output power .23
10 Calculations.27
10.1 Bend reference technique .27
10.2 Multimode reference technique .27
10.3 Curve-fitting technique for improved precision (optional) .29
11 Results .35
11.1 Information to be provided with each measurement.35
11.2 Information available upon request .35
12 Specification information.35
Annex A (normative) Requirements specific to method A – Cable cut-off wavelength,
λ , using uncabled fibre .37
cc
Annex B (normative) Requirements specific to method B – Cable cut-off wavelength,
λ , using cabled fibre .39
cc
Annex C (normative) Requirements specific to method C – Fibre cut-off wavelength, λ .41
c
Annex D (normative) Requirements specific to method D – Jumper cable cut-off
wavelength, λ .43
cj
Figure 1 – Deployment configuration for cable cut-off – Method A.19
Figure 2 – Deployment configuration for cable cut-off – Method B.19
Figure 3 – Default configuration to measure λ .19
cj
Figure 4 – Deployment configurations for fibre cut-off measurement .21
Figure 5 – Cut-off wavelength using the bend reference technique.25
Figure 6 – Cut-off wavelength using the multimode reference technique .25
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60793-1-44 © IEC:2001 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
OPTICAL FIBRES –
Part 1-44: Measurement methods and test procedures –
Cut-off wavelength
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60793-1-44 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This standard, together with the other standards in the IEC 60793-1-4X series, replaces the
second edition of IEC 60793-1-4, of which it constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
86A/673/FDIS 86A/697/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 3.
Annexes A, B, C and D form an integral part of this standard.
IEC 60793-1-1 and IEC 60793-1-2 cover generic specifications.
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60793-1-44 © IEC:2001 – 7 –
IEC 60793-1-4X consists of the following parts, under the general title: Optical fibres:
– Part 1-40: Measurement methods and test procedures – Attenuation
– 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
– Part 1-44: Measurement methods and test procedures – Cut-off wavelength
– Part 1-45: Measurement methods and test procedures – Mode field diameter
– 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 1-48: Measurement methods and test procedures – Under consideration
– Part 1-49: Measurement methods and test procedures – Under consideration
The committee has decided that the contents of this publication will remain unchanged until
2003. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
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60793-1-44 © IEC:2001 – 9 –
INTRODUCTION
Publications in the IEC 60793-1 series concern measurement methods and test procedures as
they apply to optical fibres.
Within the same series several different areas are grouped, as follows:
– parts 1-10 to 1-19: General
– parts 1-20 to 1-29: Measurement methods and test procedures for dimensions
– parts 1-30 to 1-39: Measurement methods and test procedures for mechanical charac-
teristics
– parts 1-40 to 1-49: Measurement methods and test procedures for transmission and optical
characteristics
– parts 1-50 to 1-59: Measurement methods and test procedures for environmental charac-
teristics.
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60793-1-44 © IEC:2001 – 11 –
OPTICAL FIBRES –
Part 1-44: Measurement methods and test procedures –
Cut-off wavelength
1 Scope
This part of IEC 60793 establishes uniform requirements for measuring the cut-off wavelength
of single-mode optical fibre, thereby assisting in the inspection of fibres and cables for
commercial purposes.
This standard provides methods for measuring the cut-off wavelength of cable, fibre, and
jumper cable.
Two methods exist for measuring cable cut-off wavelength, λ :
cc
– method A: using uncabled fibre;
– method B: using cabled fibre.
There is only one method for measuring fibre cut-off wavelength, λ .
c
There is only one method for measuring jumper cable fibre cut-off wavelength, λ .
cj
The test method in this standard describes procedures for determining the cut-off wavelength
of a sample fibre in either an uncabled condition (λ ) or in a cable (λ ) or as a jumper cable
c cc
(λ ). Three default configurations are given here: any different configuration will be given in a
cj
detail specification. This method applies to all B fibre types.
All methods require a reference measurement. There are two reference-scan techniques,
either or both of which may be used with all methods:
– bend-reference technique;
– multimode-reference technique.
2 Normative references
None.
3 Background
Theoretical cut-off wavelength is the shortest wavelength at which only the fundamental mode
can propagate in a single-mode fibre, as computed from the refractive index profile of the fibre.
In optical fibres, the change from multimode to single-mode behaviour does not occur at an
isolated wavelength, but rather it occurs smoothly over a range of wavelengths. For purposes
of determining fibre performance in a telecommunications network, theoretical cut-off wave-
length is less useful than the lower value actually measured when the fibre is deployed.
Measured cut-off wavelength is defined as the wavelength greater than which the ratio between
the total power, including launched higher-order modes, and the fundamental mode power has
decreased to less than 0,1 dB. According to this definition, the second-order (LP ) mode
11
undergoes 19,3 dB more attenuation than the fundamental (LP ) mode.
01
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60793-1-44 © IEC:2001 – 13 –
Because measured cut-off wavelength depends on the length and bends of the fibre, the
resulting value of cut-off wavelength depends on whether the measured fibre is configured in a
deployed, cabled condition, or it is short and uncabled. Consequently, there are three overall
types of cut-off wavelength:
a) cable cut-off wavelength, measured in an uncabled fibre deployment condition (method A),
or in a cabled condition (method B);
b) fibre cut-off wavelength, measured on a short length of uncabled, primary-coated fibre;
c) jumper cable cut-off wavelength, λ , measured on short length of jumper cable deployed
cj
with a single loop.
Cable cut-off wavelength is the preferred attribute to be specified and measured.
4 Overview of methods
All of the methods shall use the transmitted power technique, which measures the variation
with wavelength of the transmitted power of a fibre under test compared to a reference
transmitted power wavelength scan. The reference scan normalizes wavelength-dependent
fluctuations in the measurement equipment so that the attenuation of the LP mode in the
11
specimen can be properly characterized and the cut-off wavelength precisely determined.
The reference scan uses one of the following two techniques:
– the specimen with an additional, smaller-radius fibre bend;
– a (separate) multimode fibre.
This procedure can determine the cut-off wavelength of a fibre specimen in either a cabled or
uncabled condition. Each method has its own default configurations; the detail specification will
give any different configuration required.
The fibre cut-off wavelength, (λ ), measured under the standard length and bend conditions
c
described in this standard, will generally exhibit a value larger than λ . For normal installed
cc
cable spans, it is common for the measured λ value to exceed the system transmission
c
wavelength. Thus cable cut-off wavelength is the more useful description of system
performance and capability. For short cables, e.g. pigtail with a length shorter (and possibly a
bending radius larger) than described in this method, the cable may become multimode at
wavelengths larger than λ .
cc
Where the cable length is even shorter than described in the fibre cut-off wavelength
measurement, the cable can become multimode at wavelengths larger than λ .
c
Jumper cable cut-off will generally produce a value between cable cut-off wavelength and fibre
cut-off wavelength. The value is affected by the jumper cable construction to a greater degree
than it is affected by regular transmission cable. The choice of bend radius will also affect the
result. The bend radius should be specified to be similar to the field deployment condition.
Jumper cable cut-off wavelength can be specified for a particular construction, for applications
using lengths between the specified measurement length and 20 m, and for application bend
radii greater than the specified measurement bend radius.
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60793-1-44 © IEC:2001 – 15 –
5 Mapping functions
A mapping function is a formula by which the measured results of one type of cut-off
wavelength are used to predict the results that one would obtain from another type.
An empirical mapping function is specific to a particular fibre type and design. Generate
mapping functions by doing an experiment in which samples of fibre are chosen to represent
the spectrum of cut-off values for the fibre type, then measuring the values using the two
methods to be mapped. Linear regression of
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