IEC 61300-3-14:2014

Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-14: Examinations and measurements - Error and repeatability of the attenuation settings of a variable optical attenuator

IEC 61300-3-14:2014 provides a method to measure the error and repeatability of the attenuation value settings of a variable optical attenuator (VOA). There are two control technologies for VOAs, manually controlled and electrically controlled. This standard covers both control technologies of VOAs and also covers both single-mode and multimode fibre VOAs. This third edition cancels and replaces the second edition published in 2006 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- title modification replacing the word "accuracy" by "error";
- inclusion of the distinction of manually and electrically controlled variable optical attenuators in the Scope;
- revision of clauses for apparatus and details to be specified to harmonize with other standards in the IEC 61300 series;
- addition of "the maximum deviation of attenuation from setting" to the clause for calculation;
- addition of "measurement method of hysteresis characteristics" in Annex B. Keywords: attenuation value settings, variable optical attenuator (VOA)

Dispositifs d’interconnexion et composants fibroniques – Procédures fondamentales d’essais et de mesures – Partie 3-14: Examens et mesures – Erreur et répétabilité des positions d’affaiblissement d’un affaiblisseur optique variable

IEC 61300-3-14:2014 fournit une méthode destinée à mesurer l'erreur et répétabilité des réglages des valeurs d'affaiblissement d'un affaiblisseur optique variable (VOA, variable optical attenuator). Il existe deux technologies de commande pour les VOA, à commande manuelle et à commande électrique. La présente norme couvre ces deux technologies de commande des VOA, ainsi que les VOA à fibres unimodales et multimodales. Cette troisième édition annule et remplace la deuxième édition publiée en 2006, et constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- modification du titre visant à remplacer le terme "précision" par "erreur";
- intégration dans le Domaine d'application de la distinction entre les affaiblisseurs optiques variables à commande manuelle et électrique;
- révision des articles relatifs à l'appareillage et précisions en vue de l'harmonisation avec d'autres normes de la série 61300;
- ajout de “l'écart maximal d’affaiblissement par rapport au réglage” dans l'article relatif au calcul;
- ajout de “méthode de mesure des caractéristiques d'hystérésis” dans l'Annexe B.
Mots clés: réglages des valeurs d'affaiblissement, affaiblisseur optique variable (VOA, variable optical attenuator).

General Information

• Status: Published
• Publication Date: 09-Oct-2014
• ICS: 17.020 - Metrology and measurement in general
• ICS: 33.120.10 - Coaxial cables. Waveguides
• ICS: 33.180.20 - Fibre optic interconnecting devices
• Technical Committee: SC 86B - Fibre optic interconnecting devices and passive components
• Drafting Committee: WG 4 - TC 86/SC 86B/WG 4
• Current Stage: PPUB - Publication issued
• Start Date: 10-Oct-2014
• Completion Date: 15-Nov-2014

Relations

• Revised: IEC 61300-3-14:2025 - Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-14: Examinations and measurements - Error and repeatability of the attenuation settings of a variable optical attenuator
• Effective Date: 05-Sep-2023
• Revises: IEC 61300-3-14:2006 - Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-14: Examinations and measurements - Accuracy and repeatability of the attenuation settings of a variable attenuator
• Effective Date: 05-Sep-2023

Overview

IEC 61300-3-14:2014 specifies a standardized method to measure the error and repeatability of attenuation value settings of a variable optical attenuator (VOA). Applicable to both manually controlled and electrically controlled VOAs, the standard covers single‑mode and multimode fibre devices. Measurements consist of stepping a VOA through prescribed nominal attenuation settings, recording measured attenuation at each setting, repeating the sequence, and deriving error and repeatability statistics.

This is Edition 3 (2014) and introduces technical revisions including:

• title change from “accuracy” to “error”;
• explicit inclusion of manual vs. electrical control VOAs;
• harmonized apparatus and specification clauses within the IEC 61300 series;
• addition of maximum deviation of attenuation from setting to calculations;
• addition of a hysteresis measurement method (Annex B).

Key topics and requirements

• Measurement objectives: determine attenuation error (difference between mean measured and nominal setting) and repeatability (±3·standard deviation of repeated measurements).
• Types of calibration: supports VOAs with absolute and relative (zero‑point referenced) attenuation calibration.
• Apparatus and conditions:
  • Light source stability requirement: ≤ 0.05 dB over one hour; wavelength and spectral width must match VOA operating range.
  • Source/detector dynamic range: at least 10 dB greater than the maximum attenuation to be measured.
  • Detector minimum resolution: ≤ 0.01 dB; linearity and high dynamic range are emphasized.
  • For single‑mode VOAs, polarization dependent loss (PDL) may affect results - use random polarization or characterize PDL.
  • Use of reference fibre, temporary joints and launch conditions per IEC 61300-3-4 / IEC 61300-1.
• Calculations: includes error for absolute and relative calibrations, maximum deviation across settings, and repeatability metrics.
• Hysteresis: Annex B provides a measurement method to quantify hysteresis characteristics.

Practical applications

• Certifying VOA performance for telecommunications, test systems, and laboratory equipment.
• Verifying manufacturer specifications during production test and incoming inspection.
• Characterizing VOAs used in tunable systems, optical attenuator modules, and optical component validation.
• Ensuring reliable attenuation control for optical system design, link budgeting, and automated test equipment.

Who should use this standard

• VOA manufacturers and design engineers
• Test laboratories and QA departments
• Component integrators and system vendors
• Procurement and compliance teams evaluating VOA performance

Related standards

• IEC 61300-1 (General guidance)
• IEC 61300-3-4 (Attenuation measurement and launch conditions)
• Other parts of the IEC 61300 series for fibre optic interconnecting devices and passive components

Keywords: attenuation value settings, variable optical attenuator (VOA), VOA error, VOA repeatability, IEC 61300-3-14:2014.

Standards Content (Sample)

IEC 61300-3-14 ®
Edition 3.0 2014-10
INTERNATIONAL
STANDARD
Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures –
Part 3-14: Examinations and measurements – Error and repeatability of the
attenuation settings of a variable optical attenuator
IEC 61300-3-14:2014-10(en)
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
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IEC 61300-3-14 ®
Edition 3.0 2014-10
INTERNATIONAL
STANDARD
Fibre optic interconnecting devices and passive components – Basic test and

measurement procedures –
Part 3-14: Examinations and measurements – Error and repeatability of the

attenuation settings of a variable optical attenuator

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
M
ICS 33.180.20 ISBN 978-2-8322-1885-3

– 2– IEC 61300-3-14:2014 © IEC:2014
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 General description . 5
4 Apparatus . 7
4.1 Light source (S) and launch conditions . 7
4.2 Detector (D) . 7
4.3 Reference fibre (RF) . 7
4.4 Temporary joint (TJ) . 7
5 Measurement procedure . 8
5.1 Measurement set-up . 8
5.2 Measurement procedure . 8
6 Calculation . 8
6.1 Attenuation error for VOAs with absolute calibration . 8
6.2 Attenuation error for VOAs with relative calibration . 9
6.3 Maximum deviation of attenuation from setting for all attenuation levels. 9
6.4 Repeatability of attenuation . 9
7 Measurement report . 9
8 Details to be specified . 10
8.1 General . 10
8.2 Light source and launch condition . 10
8.3 Detector . 10
8.4 Reference fibre . 10
8.5 Temporary joint . 10
8.6 DUT . 10
8.7 Measurement procedure . 10
8.8 Measurement uncertainty . 10
8.9 Others. 10
Annex A (informative) Example of a sample measurment record . 11
Annex B (informative) Measurement method of hysteresis characteristics . 12
B.1 General . 12
B.2 Measurement procedure . 12
B.3 Calculation . 12

Figure 1 – Measured versus nominal attenuation . 6
Figure 2 – Measurement set-up . 8

Table A.1 – Device performance specifications versus actual performance . 11

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC INTERCONNECTING
DEVICES AND PASSIVE COMPONENTS –
BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-14: Examinations and measurements –
Error and repeatability of the attenuation settings
of a variable optical attenuator

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
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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
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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 61300-3-14 has been prepared by subcommittee 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This third edition cancels and replaces the second edition published in 2006 and constitutes a
technical revision
This edition includes the following significant technical changes with respect to the previous
edition:
a) title modification replacing the word "accuracy" by "error";
b) inclusion of the distinction of manually and electrically controlled variable optical
attenuators in the Scope;
– 4– IEC 61300-3-14:2014 © IEC:2014
c) revision of clauses for apparatus and details to be specified to harmonize with other
standards in the IEC 61300 series;
d) addition of “the maximum deviation of attenuation from setting” to the clause for
calculation;
e) addition of “measurement method of hysteresis characteristics” in Annex B.
The text of this standard is based on the following documents:
FDIS Report on voting
86B/3816/FDIS 86B/3843/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.
A bilingual version of this publication may be issued at a later date.

FIBRE OPTIC INTERCONNECTING
DEVICES AND PASSIVE COMPONENTS –
BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-14: Examinations and measurements –
Error and repeatability of the attenuation settings
of a variable optical attenuator

1 Scope
...

IEC 61300-3-14 ®
Edition 3.0 2014-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures –
Part 3-14: Examinations and measurements – Error and repeatability of the
attenuation settings of a variable optical attenuator

Dispositifs d’interconnexion et composants fibroniques – Procédures
fondamentales d’essais et de mesures –
Partie 3-14: Examens et mesures – Erreur et répétabilité des positions
d’affaiblissement d’un affaiblisseur optique variable

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IEC 61300-3-14 ®
Edition 3.0 2014-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and

measurement procedures –
Part 3-14: Examinations and measurements – Error and repeatability of the

attenuation settings of a variable optical attenuator

Dispositifs d’interconnexion et composants fibroniques – Procédures

fondamentales d’essais et de mesures –

Partie 3-14: Examens et mesures – Erreur et répétabilité des positions

d’affaiblissement d’un affaiblisseur optique variable

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.20 ISBN 978-2-8322-7386-9

– 2 – IEC 61300-3-14:2014 © IEC:2014
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 General description . 5
4 Apparatus . 7
4.1 Light source (S) and launch conditions . 7
4.2 Detector (D) . 7
4.3 Reference fibre (RF) . 7
4.4 Temporary joint (TJ) . 7
5 Measurement procedure . 8
5.1 Measurement set-up . 8
5.2 Measurement procedure . 8
6 Calculation . 8
6.1 Attenuation error for VOAs with absolute calibration . 8
6.2 Attenuation error for VOAs with relative calibration . 9
6.3 Maximum deviation of attenuation from setting for all attenuation levels. 9
6.4 Repeatability of attenuation . 9
7 Measurement report . 9
8 Details to be specified . 10
8.1 General . 10
8.2 Light source and launch condition . 10
8.3 Detector . 10
8.4 Reference fibre . 10
8.5 Temporary joint . 10
8.6 DUT . 10
8.7 Measurement procedure . 10
8.8 Measurement uncertainty . 10
8.9 Others. 10
Annex A (informative) Example of a sample measurment record . 11
Annex B (informative) Measurement method of hysteresis characteristics . 12
B.1 General . 12
B.2 Measurement procedure . 12
B.3 Calculation . 12

Figure 1 – Measured versus nominal attenuation . 6
Figure 2 – Measurement set-up . 8

Table A.1 – Device performance specifications versus actual performance . 11

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC INTERCONNECTING
DEVICES AND PASSIVE COMPONENTS –
BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-14: Examinations and measurements –
Error and repeatability of the attenuation settings
of a variable optical attenuator

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 61300-3-14 has been prepared by subcommittee 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This bilingual version (2019-09) corresponds to the monolingual English version, published in
2014-10.
This third edition cancels and replaces the second edition published in 2006 and constitutes a
technical revision
This edition includes the following significant technical changes with respect to the previous
edition:
a) title modification replacing the word "accuracy" by "error";

– 4 – IEC 61300-3-14:2014 © IEC:2014
b) inclusion of the distinction of manually and electrically controlled variable optical attenuators
in the Scope;
c) revision of clauses for apparatus and details to be specified to harmonize with other
standards in the IEC 61300 series;
d) addition of “the maximum deviation of attenuation from setting” to the clause for calculation;
e) addition of “measurement method of hysteresis characteristics” in Annex B.
The text of this standard is based on the following documents:
FDIS Report on voting
86B/3816/FDIS 86B/3843/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.
The French version of this standard has not been voted upon.
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.
FIBRE OPTIC INTERCONNECTING
DEVICES AND PASSIVE COMPONENTS –
BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-14: Examinations and measurements –
Error and repeatability of the attenuation settings
of a variable optical attenuator

1 Scope
This part of IEC 61300 provides a method to measure the error and repeatability of the
attenuation value settings of a variable optical attenuator (VOA). There are two control
technologies for VOAs, manually controlled and electrically controlled. This standard covers
both control technologies of VOAs and also covers both single-mode and multimode fibre VOAs.
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.
IEC 61300-1, Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures – Part 1: General and guidance
IEC 61300-3-4, Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures – Part 3-4:Examinations and measurements − Attenuation
3 General description
A variable optical attenuator is adjusted sequentially through a series of nominal attenuation
settings prescribed in the relevant specification. For an electrically controlled VOA, the
attenuation is set by applying electrical voltage or current to the device.
There are two categories of VOAs:
– those that can be adjusted to nominal attenuation levels;
– those that have no information on the nominal attenuation levels.
Some manually controlled VOAs have a scaled dial to indicate the nominal attenuation levels.
Some electrically controlled VOAs have a table (or equation) indicating the applied voltage (or
current) corresponding to nominal attenuation levels. This measurement method of attenuation
error and repeatability can only be applied to VOAs which can be adjusted to nominal
attenuation levels.
In this type of measurement, the attenuation value is measured at each setting. This sequence
of measurements is repeated a number of times as prescribed in the relevant specification. The
error of the attenuator at each setting is then given by the difference between the mean of the
measured values and the nominal value. The repeatability at each setting is given by a value
of plus and minus three times the standard deviation of the measurements.

– 6 – IEC 61300-3-14:2014 © IEC:2014
Generally the nominal attenuation levels are provided in different two ways, i.e. absolute or
relative attenuation calibration levels. Figure 1a characterizes an attenuator which is calibrated
to read the actual or measured attenuation. Figure 1b characterizes an attenuator for which the
manufacturer provides the calibration results relative to a zero-point setting. When the
attenuator is adjusted to read zero, the actual or measured attenuation will be some value
greater than zero.
Figure 1a – Absolute calibration of attenuation

Figure 1b − Calibration relative to zero-point setting
Figure 1 – Measured versus nominal attenuation

4 Apparatus
4.1 Light source (S) and launch conditions
The output power of the light source shall be sufficiently high to permit a sufficiently large
measurement dynamic range with the optical detector used. The output power stability shall be
less than or equal to 0,05 dB over one hour. The dynamic range of the source/detector
combination shall be at least 10 dB greater than the absolute value of the maximum attenuation
value to be measured. However the output power into the fibre shall not exceed the maximum
operating input power rating of the VOA to be tested.
The wavelength and spectral width of the light source shall correspond to the operating
wavelength range and calibration settings of the VOA to be measured.
For the measurement of single-mode VOAs, polarization dependent loss (PDL) may influence
the error and repeatability of attenuation values. Unless otherwise specified, random
polarization states shall be used or the PDL shall also be characterized.
Other requirements of the light source and launch conditions shall be in accordance with
IEC 61300-3-4. An excitation unit shall be used to satisfy the launch condition defined in
IEC 61300-1, if necessary. Moreover cladding modes shall be stripped as typically achieved by
the fibre coating, so that they do not affect the measurement.
4.2 Detector (D)
A high dynamic range optical power meter should be used for the detector. Its wavelength range
shall be wider than the operating wavelength range of the VOA to be measured. In order to
make measurements with low uncertainty, the linearity of the optical power meter is most
important for the error and repeatability of VOA measurements. The minimum resolution of the
detector shall be ≤0,01 dB.
Other requirements of detector shall be in accordance with IEC 61300-3-4.
4.3 Reference fibre (RF)
In order to measure the output power of the light source, a reference fibre is used. The reference
fibre shall be of the same performance as the pigtail fibre of the VOA to be measured.
4.4 Temporary joint (TJ)
This is a method, device or mechanical fixture for temporarily aligning two fibre ends into a
stable, reproducible, low-loss joint. It is used when direct connection of the device under test
(DUT) to the measurement system is not achievable by a standard connector. It may, for
example, be a precision V-groove, vacuum chuck, a micromanipulator, or a fusion or mechanical
splice. The temporary joint shall be stable to within ±10 % of the measurement uncertainty
required in dB over the time taken to measure P and P . A suitable refractive index matching
0 n
material may be used to improve the stability of the TJ.
Patchcords with direct connection to the light source may be used and the use of TJs is not
mandatory.
– 8 – IEC 61300-3-14:2014 © IEC:2014
5 Measurement procedure
5.1 Measurement set-up
Figure 2 shows the measurement set-up.
The position of the fibres during the measurement shall remain fixed between the measurement
of P and P to avoid changes in attenuation due to bending losses.
0 n
Figure 2a – Measurement of reference power

Figure 2b – Measurement of attenuation
Figure 2 – Measurement set-up
5.2 Measurement procedure
The measurement procedure is as follows:
.
a) Assemble the measurement set-up as shown in Figure 2a and measure P
b) Insert the VOA to be measured (DUT) into the measurement set-up as shown in Figure 2b.
c) Adjust the DUT to the lowest attenuation level and record the power level of P .
d) Increase the attenuation of the DUT to the next lowest attenuation level and record the
power level of P .
e) Continue to measure and record the power levels of P , P , ….P , increasing the
3 4 n
attenuation levels to the next higher attenuation level for each step.
f) Repeat steps c) to e) and record a second set of readings P (2) to P (2).
1 n
g) Repeat step f) for the number of times m specified in the relevant specification.
6 Calculation
6.1 Attenuation error for VOAs with absolute calibration
th
Calculate the error of the i attenuation setting using the following equation:
δa = a − A (dB) (1)
i i i
where
a (n) = −10log10[P(n)/P ] (dB) (2)
i i 0
m
a = a ( j) (dB) (3)
i i
∑
m
j =1
th
and where A is the i nominal attenuation setting (dB).
i
6.2 Attenuation error for VOAs with relative calibration
th
Calculate the error of the i attenuation setting using the following equation:
(dB) (4)
δa = a − a − A
i i 1
i
a
where is the mean value of the zero point attenuation.
6.3 Maximum deviation of attenuation from setting for all attenuation levels
The maximum deviation of attenuation from setting for all attenuation levels can be calculated
using the following equation:
( )
δa = max δa
(dB) (5)
max i =1−n i
6.4 Repeatability of attenuation
Calculate the 3σ-repeatability of attenuation by
∆a = ± 3 σ
(dB) (6)
i i
where σ is the standard deviation of the measurements calculated by the following equation:
i
n
(dB) (7)
σ = (a ( j) − a )
i i i
∑
n
j =1
A minimum of m = 10 measurements at each setting are recommended to provide a reasonable
estimate of σ .
i
7 Measurement report
The following values shall be described in the measurement report. Annex A shows an example
of a sample measurement record.
th
– i nominal attenuation level, A ;
i
th
– error of the i attenuation levels, δa ;
i
– maximum deviation of attenuation from setting for all attenuation levels, δa ;
max
.
– repeatability of ith attenuation levels, ∆a
i
It is recommended that a chart plotting the measurement result such as those shown in
Figure 1a or Figure 1b is included in the measurement report.

– 10 – IEC 61300-3-14:2014 © IEC:2014
8 Details to be specified
8.1 General
The following details, as applicable, shall be specified in the relevant specification and/or
recorded in the measurement report.
8.2 Light source and launch condition
– Type of light source
– Centre wavelength
– Spectral width
– Output power
– Power stability during measurement
– Type of measurement method of polarization dependency (when used)
– Type of mode filter and launch condition (when used)
8.3 Detector
– Type of detector
– Dynamic range of sensitivity
– Linearity of sensitivity
– Polarization dependency of sensitivity
8.4 Reference fibre
– Category of reference fibre
– Fibre length
– Fibre jacket type
8.5 Temporary joint
– Type of temporary joint
– Nominal return loss of temporary joint
– Nominal attenuation of temporary joint
8.6 DUT
– Device performance specifications versus actual performance
8.7 Measurement procedure
– Attenuation settings measured
– Number of measurements at each setting (m)
8.8 Measurement uncertainty
8.9 Others
– Deviations from this measuring procedure

Annex A
(informative)
Example of a sample measurment record

The following example is for illustration only and does not indicate recommended apparatus or
measuring conditions.
• Source description: 1 307 nm Fabry-Perot laser source
• Excitation unit description: None
• Detector description: InGaAs power sensor
• Reference fibre: Cut-back section of attenuator input port
• Reference connector set: None
• Temporary joint: Fusion splice
• Reference fibre lengths: 0,25 m
• Pigtail fibre length of VOA: 1 m
• Preconditioning procedure: Standard atmospheric conditions for 24 h as per IEC 61300 -1
• Attenuation settings to be measured: Minimum setting, 10 dB, 20 dB, 30 dB, 40 dB, 50 dB
and 60 dB
• Number of measurements at each setting: m = 10
• Deviations from this test procedure: P measured by cut-back of attenuator input port
• Device performance specifications versus actual performance: see Table A.1 below
Table A.1 – Device performance specifications versus actual performance
Setting Nominal values Measured values
(i) Attenuation Error Repeatability Attenuation Error Repeatability
A δa ∆a a δa ∆a
i i i i i i
dB dB
dB ±dB dB ±dB
1 1,4 1,7 0,11
<0,5 <0,3 +0,3
2 10 <0,5 <0,3 9,8 −0,2 0,16
3 20 19,7 0,23
<0,5 <0,4 −0,3
4 30 30,0  0,0 0,30
<0,5 <0,4
5 40 <0,5 <0,5 40,3 +0,3 0,33
6 50 50,4 0,39
<0,5 <0,5 +0,4
7 60 <0,5 <0,6 60,4 +0,4 0,41
Maximum 0,41
+0,4
– − − −
– 12 – IEC 61300-3-14:2014 © IEC:2014
Annex B
(informative)
Measurement method of
...