SIST EN 60793-1-44:2011

Optical fibres - Part 1-44: Measurement methods and test procedures - Cut-off wavelength (IEC 60793-1-44:2011)

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 gives the methods for measuring the cut-off wavelength of fibre and cable There are two methods for measuring cable cut-off wavelength, l cc: ? Method A: using uncabled fibre; ? Method B: using cabled fibre. There is only one method (Method C) for measuring fibre cut-off wavelength, l c. The test method in this standard describes procedures for determining the cut-off wavelength of a sample fibre in either an uncabled condition (l c) or in a cable (l cc). Three default configurations are given here: any different configuration will be given in a detail specification. These procedures apply to all category B and C fibre types (see Normative references). 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 using category A1 multimode fibre.

Lichtwellenleiter - Messmethoden und Prüfverfahren - Teil 1-44: Grenzwellenlänge (IEC 60793-1-44:2011)

Fibres optiques - Partie 1-44: Méthodes de mesure et procédures d'essai - Longueur d'onde de coupure (CEI 60793-1-44:2011)

La CEI 60793-1-44:2011 établit des exigences uniformes pour mesurer la longueur d'onde de coupure des fibres optiques unimodales, contribuant ainsi au contrôle des fibres et câbles dans des relations commerciales. La présente norme donne les méthodes de mesure de la longueur d'onde de coupure de fibre et de câble. Cette deuxième édition annule et remplace la première édition parue en 2001. Elle constitue une révision technique. La principale modification par rapport à l'édition précédente consiste en la suppression de l'Annexe D.
Cette publication doit être lue conjointement avec la CEI 60793-1-1:2008.

Optična vlakna - 1-44. del: Metode merjenja in preskusni postopki - Mejna valovna dolžina (IEC 60793-1-44:2011)

Ta del IEC 60793 vzpostavlja enotne zahteve za merjenje mejne valovne dolžine enorodnih optičnih vlaken in je z njimi opora pri pregledovanju vlaken in kablov v komercialne namene. Ta standard navaja metode za merjenje mejne optične dolžine vlaken in kablov. Za merjenje mejne valovne dolžine kablov obstajata dve metodi, l cc:? Metoda A: z uporabo vlaken zunaj kabla; ? Metoda B: z uporabo vlaken v kablu. Za merjenje mejne valovne dolžine vlaken, 1 c, obstaja samo ena metoda (metoda C). Preskusna metoda v tem standardu opisuje postopke za določanje mejne valovne dolžine vzorčnega vlakna v stanju zunaj kabla (l c) ali v kablu (l cc). Podane so tri privzete konfiguracije: vsaka drugačna konfiguracija je navedena v podrobni specifikaciji. Ti postopki veljajo za vse vrste vlaken kategorij B in C (glej Normativne reference). Vse metode zahtevajo referenčno meritev. Obstajate dve tehniki z referenčnim odčitavanjem in obe se lahko uporabljata z vsemi metodami: ? tehnika z referenčnim upogibanjem; tehnika z večrodno referenco z uporabo večrodnega vlakna kategorije A1.

General Information

• Status: Published
• Publication Date: 06-Jul-2011
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: MOC - Mobile Communications
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 22-Jun-2011
• Due Date: 27-Aug-2011
• Completion Date: 07-Jul-2011
• Ref Project: EN 60793-1-44:2011 - Optical fibres - Part 1-44: Measurement methods and test procedures - Cut-off wavelength

Relations

• Replaces: SIST EN 60793-1-44:2004 - Optical fibres -- Part 1-44: Measurement methods and test procedures - Cut-off wavelength
• Effective Date: 28-Jan-2023
• Revised: SIST EN 60793-1-44:2004 - Optical fibres -- Part 1-44: Measurement methods and test procedures - Cut-off wavelength
• Effective Date: 06-May-2014
• Revised: SIST EN IEC 60793-1-44:2023 - Optical fibres - Part 1-44: Measurement methods and test procedures - Cut-off wavelength (IEC 60793-1-44:2023)
• Effective Date: 18-May-2021

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 60793-1-44:2011
01-september-2011
1DGRPHãþD
SIST EN 60793-1-44:2004
2SWLþQDYODNQDGHO0HWRGHPHUMHQMDLQSUHVNXVQLSRVWRSNL0HMQDYDORYQD
GROåLQD,(&
Optical fibres - Part 1-44: Measurement methods and test procedures - Cut-off
wavelength (IEC 60793-1-44:2011)
Lichtwellenleiter - Messmethoden und Prüfverfahren - Teil 1-44: Grenzwellenlänge (IEC
60793-1-44:2011)
Fibres optiques - Partie 1-44: Méthodes de mesure et procédures d'essai - Longueur
d'onde de coupure (CEI 60793-1-44:2011)
Ta slovenski standard je istoveten z: EN 60793-1-44:2011
ICS:
33.180.10 2SWLþQDYODNQDLQNDEOL Fibres and cables
SIST EN 60793-1-44:2011 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60793-1-44:2011

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SIST EN 60793-1-44:2011

EUROPEAN STANDARD
EN 60793-1-44

NORME EUROPÉENNE
June 2011
EUROPÄISCHE NORM

ICS 33.180.10 Supersedes EN 60793-1-44:2002


English version


Optical fibres -
Part 1-44: Measurement methods and test procedures -
Cut-off wavelength
(IEC 60793-1-44:2011)


Fibres optiques -  Lichtwellenleiter -
Partie 1-44: Méthodes de mesure et Messmethoden und Prüfverfahren -
procédures d'essai - Teil 1-44: Grenzwellenlänge
Longueur d'onde de coupure (IEC 60793-1-44:2011)
(CEI 60793-1-44:2011)




This European Standard was approved by CENELEC on 2011-05-25. 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, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Management Centre: Avenue Marnix 17, B - 1000 Brussels


© 2011 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60793-1-44:2011 E

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SIST EN 60793-1-44:2011
EN 60793-1-44:2011 - 2 -
Foreword
The text of document 86A/1369/FDIS, future edition 2 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 2011-05-25.
This European Standard supersedes EN 60793-1-44:2002.
The main change with respect to EN 60793-1-44:2002 is the withdrawal of Annex D.
Annexes A, B and C form an integral part of EN 60793-1-44:2011.
This standard should be read in conjunction with EN 60793-1-1.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2012-02-25
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2014-05-25
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60793-1-44:2011 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60793-2-10 NOTE  Harmonized as EN 60793-2-10.
IEC 60793-2-50 NOTE  Harmonized as EN 60793-2-50.
IEC 60793-2-60 NOTE  Harmonized as EN 60793-2-60.
__________

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SIST EN 60793-1-44:2011
- 3 - EN 60793-1-44:2011
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

IEC 60793-1-1 - Optical fibres - EN 60793-1-1 -
Part 1-1: Measurement methods and test
procedures - General and guidance


IEC 60793-1-40 - Optical fibres - EN 60793-1-40 -
(mod) Part 1-40: Measurement methods and test
procedures - Attenuation

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SIST EN 60793-1-44:2011

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SIST EN 60793-1-44:2011
IEC 60793-1-44
®

Edition 2.0 2011-04
INTERNATIONAL
STANDARD


Optical fibres –
Part 1-44: Measurement methods and test procedures – Cut-off wavelength


INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
S
ICS 33.180.10 ISBN 978-2-88912-451-0
® Registered trademark of the International Electrotechnical Commission

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SIST EN 60793-1-44:2011
– 2 – 60793-1-44 ã IEC:2011(E)
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Background . 6
4 Overview of methods . 7
5 Mapping functions . 7
6 Reference test method . 8
7 Apparatus . 8
7.1 Light source . 8
7.2 Modulation . 8
7.3 Launch optics . 8
7.4 Support and positioning apparatus . 8
7.5 Cladding mode stripper . 8
7.6 Deployment mandrel . 9
7.6.1 General . 9
7.6.2 Cable cut-off wavelength, Method A . 9
7.6.3 Cable cut-off wavelength, Method B . 9
7.6.4 Fibre cut-off wavelength, Method C . 9
7.7 Detection optics . 11
7.8 Detector assembly and signal detection electronics . 11
8 Sampling and specimens . 11
8.1 Specimen length. 11
8.2 Specimen end face . 12
9 Procedure . 12
9.1 Positioning of specimen in apparatus . 12
9.1.1 General requirements for all methods . 12
9.1.2 Deployment requirements for each method . 12
9.2 Measurement of output power . 12
9.2.1 Overview . 12
9.2.2 Bend-reference technique . 13
9.2.3 Multimode-reference technique . 13
10 Calculations . 13
10.1 Bend-reference technique . 13
10.2 Multimode-reference technique . 14
10.3 Curve-fitting technique for improved precision (optional) . 14
10.3.1 General . 14
10.3.2 Step 1, define the upper-wavelength region . 15
10.3.3 Step 2, characterize the attenuation curve . 15
10.3.4 Step 3, determine the upper wavelength of the transition region . 16
10.3.5 Step 4, determine the lower wavelength of the transition region . 16
10.3.6 Step 5, characterize the transition region with the theoretical model . 16
10.3.7 Step 6, compute the cut-off wavelength, l . 17
c
11 Results . 17
11.1 Report the following information with each measurement: . 17
11.2 The following information shall be available upon request: . 17

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SIST EN 60793-1-44:2011
60793-1-44 ã IEC:2011(E) – 3 –
12 Specification information . 18
Annex A (normative) Requirements specific to method A – Cable cut-off wavelength,
l , using uncabled fibre . 19
cc
Annex B (normative) Requirements specific to method B – Cable cut-off wavelength,
l , using cabled fibre . 20
cc
Annex C (normative) Requirements specific to method C – Fibre cut-off wavelength,
l . 21
c
Bibliography . 22

Figure 1 – Deployment configuration for cable cut-off wavelength, method A . 9
Figure 2 – Deployment configuration for cable cut-off wavelength, method B . 10
Figure 3 – Default configuration to measure l . 10
c
Figure 4 – Deployment configurations for fibre cut-off measurement . 11
Figure 5 – Cut-off wavelength using the bend-reference technique . 12
Figure 6 – Cut-off wavelength using the multimode-reference technique . 13

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SIST EN 60793-1-44:2011
– 4 – 60793-1-44  IEC:2011(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

OPTICAL FIBRES –

Part 1-44: Measurement methods and test procedures –
Cut-off wavelength

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of 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, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. 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 second edition cancels and replaces the first edition published in 2001. This edition
constitutes a technical revision.
The main change with respect to the previous edition is the withdrawal of annex D.
Annexes A, B and C form an integral part of this standard.
This standard should be read in conjunction with IEC 60793-1-1.

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SIST EN 60793-1-44:2011
60793-1-44 ã IEC:2011(E) – 5 –

The text of this standard is based on the following documents:
FDIS Report on voting
86A/1369/FDIS 86A/1385/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 of the IEC 60793-1-4x series, published under the general title Optical fibres
– measurement methods and test 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.
A bilingual version of this publication may be issued at a later date.

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SIST EN 60793-1-44:2011
– 6 – 60793-1-44 ã IEC:2011(E)
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 gives the methods for measuring the cut-off wavelength of fibre and cable
There are two methods for measuring cable cut-off wavelength, l :
cc
· Method A: using uncabled fibre;
· Method B: using cabled fibre.
There is only one method (Method C) for measuring fibre cut-off wavelength, l .
c
The test method in this standard describes procedures for determining the cut-off wavelength
of a sample fibre in either an uncabled condition (l ) or in a cable (l ). Three default
c cc
configurations are given here: any different configuration will be given in a detail specification.
These procedures apply to all category B and C fibre types (see Normative references).
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 using category A1 multimode fibre.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60793-1-1, Optical fibres – Part 1-1: Measurement methods and test procedures –
General and guidance
IEC 60793-1-40, Optical fibres – Part 1-40: Measurement methods and test procedures –
Attenuation
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 smoothly over a range of wavelengths. For purposes of

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SIST EN 60793-1-44:2011
60793-1-44 ã IEC:2011(E) – 7 –
determining fibre performance in a telecommunications network, theoretical cut-off
wavelength 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 )
11
mode undergoes 19,3 dB more attenuation than the fundamental (LP ) mode at the cut-off
01
wavelength.
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 two overall
types of cut-off wavelength:
· Cable cut-off wavelength, measured in an uncabled fibre deployment condition
(method A), or in a cabled condition (method B);
· Fibre cut-off wavelength, measured on a short length of uncabled, primary-coated
fibre.
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) category A1 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, (l ), measured under the standard length and bend conditions
c
described in this standard, will generally exhibit a value larger than l . For normal installed
cc
cable spans, it is common for the measured l 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. a pigtail with a length shorter (and possibly a bending radius larger)
than described in this method, the cable may introduce modal noise near the cut-off
wavelength when lossy splices are present (>0.5 dB).
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 wavelength values for the fibre type, then measure the values using

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SIST EN 60793-1-44:2011
– 8 – 60793-1-44 ã IEC:2011(E)
the two methods to be mapped. Linear regression of the respective values will often produce
a satisfactory mapping function. When establishing criteria for fibre selection, residual errors
in the regression shall be taken into account.
The customer and the supplier shall agree to the confidence level of each mapping function
established.
6 Reference test method
Method A of cable cut-off wavelength, using uncabled fibre, is the reference test method
(RTM), which shall be the one used to settle disputes.
The apparatus for each method is described in Clause 7.
7 Apparatus
7.1 Light source
Provide a filtered white light source, with line width not greater than 10 nm, stable in position
and intensity. The light source should be capable of operating over the wavelength range
1 000 nm to 1 600 nm for most category B fibres. An operating range of 800 nm to 1 700 nm
may be necessary for some B4 fibres, B5 fibres or some category C fibres.
7.2 Modulation
Modulate the light source to prevent ambient light affecting the results, and to aid signal
recovery. A mechanical chopper with a reference output is a suitable arrangement.
7.3 Launch optics
Provide launch optics, such as a lens system or a multimode fibre, to overfill the test fibre
over the full range of measurement wavelengths. This launch is relatively insensitive to the
input end face position of the single-mode fibre, and is sufficient to excite the fundamental
and any higher-order modes in the specimen. If using a butt splice, provide means of avoiding
interference effects.
When using a multimode fibre, overfilling the reference fibre can produce an undesired ripple
effect in the power-transmission spectrum. Restrict the launch sufficiently to eliminate the
ripple effect. One example of restricted launch is in method A, attenuation by cut-back of
IEC 60793-1-40. Another example of restricted launch is a mandrel-wrap mode filter with
sufficient (approximately 4 dB) insertion loss.
7.4 Support and positioning apparatus
Provide a means to stably support the input and output ends of the specimen for the duration
of the test; vacuum chucks, magnetic chucks, or connectors may be used for this purpose.
Support the fibre ends such that they can be repeatedly positioned in the launch and
l in method B, provide a means to suitably support the
detection optics. When measuring
cc
cable ends.
7.5 Cladding mode stripper
Provide a means to remove cladding-mode power from the specimen. Under some
circumstances, the fibre coating will perform this function; otherwise, provide methods or
devices that extract cladding-mode power at the input and output ends of the specimen.

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SIST EN 60793-1-44:2011
60793-1-44 ã IEC:2011(E) – 9 –
7.6 Deployment mandrel
7.6.1 General
Use a means to stably support the input and output ends of the specimen for the duration of
the measurement. Support the fibre ends so that they can be repeatedly and stably positioned
with respect to the launch and detection optics without introducing microbends into the
specimen.
The deployment and length of the specimen, together with the support apparatus, are key
elements of the measurement method, and they distinguish the types of cut-off wavelength.
Additional, alternative deployments may be used if the results obtained have been
demonstrated to be empirically equivalent to the results obtained using the standard
deployment, to within 10 nm, or they are greater than those achieved with the standard
configurations.
7.6.2 Cable cut-off wavelength, Method A
Provide a means to make an 80 mm diameter loop at each end of the specimen and a loop of
diameter ³ 280 mm in the central portion. See Figure 1.
NOTE Two loops at one end can be substituted for one loop at each end.
7.6.3 Cable cut-off wavelength, Method B
Provide a means to make an 80 mm diameter loop at each end of the specimen.
See Figure 2.
NOTE Two loops at one end can be substituted for one loop at each end.
7.6.4 Fibre cut-off wavelength, Method C
Provide a circular mandrel as the initial fibre cut-off wavelength deployment. (See Figure 4a).
A split, semicircular mandrel with a radius of 140 mm that is capable of sliding, hence able to
take up slack fibre, is an alternative deployment . (See Figures 3 and 4b).

Æ ³ 280 mm

Æ = 80 mm Æ = 80 mm
22 m of fibre
IEC  701/11

Figure 1 – Deployment configuration for cable cut-off wavelength, method A

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SIST EN 60793-1-44:2011
– 10 – 60793-1-44 ã IEC:2011(E)


Æ = 80 mm Æ = 80 mm

1 m 1 m
20 m
IEC  702/11

Figure 2 – Deployment configuration for cable cut-off wavelength, method B
NOTE The introduction of a minimum bend of the cable sufficient to permit connection of the two ends of the
whole specimen to the measurement setup is allowed.



Receive
Launch

r
rr
Lower semicircular mandrel able
to slide to take up slack fibre
IEC  703/11

Figure 3 – Default configuration to measure l
c

L
r
IEC  704/11

Key
r = 140 mm
L = 2 m (entire fibre length)
Figure 4a) – Initial deployment configuration for fibre cut-off wavelength measurement – circular mandrel

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SIST EN 60793-1-44:2011
60793-1-44 ã IEC:2011(E) – 11 –


L L
r r r
r r
IEC  705/11

Key
r = 140 mm
L = 2 m (entire fibre length)
Figure 4b) – Alternative deployment configuration for fibre cut-off wavelength measurement – split mandrel
Figure 4 – Deployment configurations for fibre cut-off measurement
7.7 Detection optics
Couple all power emitted from the specimen onto the active region of the detector. As
examples, an optical lens system, a butt splice with a multimode fibre pigtailed to a detector,
or direct coupling may be used.
7.8 Detector assembly and signal detection electronics
Use a detector that is sensitive to the output radiation over the range of wavelengths to be
measured and that is linear over the range of intensities encountered. A typical system might
include a germanium or InGaA
...