IEC 62074-1:2014

Fibre optic interconnecting devices and passive components - Fibre optic WDM devices - Part 1: Generic specification

IEC 62074-1:2014 applies to fibre optic wavelength division multiplexing (WDM) devices. These have all of the following general features:
- they are passive, in that they contain no optoelectronic or other transducing elements;
- however they may use temperature control only to stabilize the device characteristics;
- they exclude any optical switching functions;
- they have three or more ports for the entry and/or exit of optical power, and share optical power among these ports in a predetermined fashion depending on the wavelength;
- the ports are optical fibres, or optical fibre connectors. This standard establishes uniform requirements for the following: optical, mechanical and environmental properties. This second edition cancels and replaces the first edition, published in 2009, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- substantial updating to the definitions;
- the addition of informative Annexes C to G, giving examples of technical information concerning WDM devices. Keywords: fibre optic wavelength division multiplexing, WDM, requirements for optical, mechanical and environmental properties

Dispositifs d'interconnexion et composants passifs à fibres optiques - Dispositifs WDM à fibres optiques - Partie 1: Spécification générique

L'IEC 62074-1:2014 s'applique aux dispositifs de multiplexage par répartition en longueur d'onde (WDM) à fibres optiques, dont les caractéristiques générales sont les suivantes:
- ils sont passifs, en ce qu'ils ne contiennent aucun élément optoélectronique ni autre élément de transduction;
- mais ils peuvent utiliser une commande de température uniquement dans le but de stabiliser les caractéristiques des dispositifs;
- ils excluent toute fonction de commutation optique ils possèdent au moins trois ports pour l'entrée et/ou la sortie de la puissance optique et partagent la puissance optique entre ces ports d'une façon prédéterminée en fonction de la longueur d'onde;
- les ports sont des fibres optiques ou des connecteurs à fibres optiques. La présente norme spécifie les exigences uniformes pour: les propriétés optiques, mécaniques et environnementales. Cette deuxième édition annule et remplace la première édition publiée en 2009; elle constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- mise à jour significative des définitions;
- ajout des Annexes informatives C à G présentant des exemples d'informations techniques relatives aux dispositifs WDM. Mots clés: dispositifs de multiplexage par répartition en longueur d'onde (WDM) à fibres optiques, exigence pour les propriétés optiques, mécaniques et environnementales

General Information

• Status: Published
• Publication Date: 05-Feb-2014
• ICS: 33.180.01 - Fibre optic systems in general
• ICS: 33.180.20 - Fibre optic interconnecting devices
• Technical Committee: SC 86B - Fibre optic interconnecting devices and passive components
• Drafting Committee: WG 7 - TC 86/SC 86B/WG 7
• Current Stage: PPUB - Publication issued
• Start Date: 06-Feb-2014
• Completion Date: 28-Feb-2014

Relations

• Revises: IEC 62074-1:2009 - Fibre optic interconnecting devices and passive components - Fibre optic WDM devices - Part 1: Generic specification
• Effective Date: 05-Sep-2023
• Revised: IEC 62074-1:2025 - Fibre optic interconnecting devices and passive components - Fibre optic WDM devices - Part 1: Generic specification
• Effective Date: 05-Sep-2023

Overview

IEC 62074-1:2014 is the International Electrotechnical Commission (IEC) generic specification for fibre optic wavelength division multiplexing (WDM) devices. It defines uniform requirements for passive WDM components that:

• are passive (contain no optoelectronic or transducing elements),
• may use temperature control only to stabilize characteristics,
• exclude optical switching functions,
• have three or more ports for entry/exit of optical power with wavelength-dependent power distribution,
• use optical fibres or fibre connectors as ports.

This second edition (2014) cancels and replaces the 2009 edition and includes substantial updates to definitions and new informative annexes (C–G) with examples and technical information on WDM devices.

Key Topics and Requirements

The standard establishes requirements and guidance across these technical areas:

• Terms and definitions - updated, covering channels, isolation, crosstalk, insertion loss, ripple, polarization effects, free spectral range, etc.
• Classification and marking - device types, styles, variants and identification rules.
• Documentation and specification system - required drawings, test data sheets, measurement methods and instructions for use.
• Design and construction - materials, workmanship and restrictions (passivity and no switching).
• Performance requirements - optical parameters (insertion loss, channel uniformity, isolation, crosstalk, extinction ratio, polarization-dependent effects), mechanical and environmental properties (temperature stabilization allowance, environmental testing).
• Safety and packaging - marking, package labelling and applicable safety considerations.
• Informative annexes - transfer matrix formalism, bidirectional system examples, and technology examples (thin film filters, fused fibres, AWGs, FBGs).

The standard is focused on requirements for optical, mechanical and environmental properties of fibre optic WDM devices rather than component-level manufacturing recipes.

Applications and Who Uses It

IEC 62074-1 is relevant for:

• Manufacturers specifying and verifying passive WDM modules (multiplexers, demultiplexers, wavelength routers, add/drop devices).
• Test laboratories performing standardized optical and environmental testing.
• System integrators and network designers ensuring component selection meets optical budgets and isolation/crosstalk requirements in WDM systems.
• Procurement and quality assurance teams needing uniform acceptance criteria and documentation.
• R&D and product engineers who need standardized definitions and performance metrics for component comparison.

Common application domains include DWDM/CWDM passive devices for telecom, access networks, metropolitan networks and passive optical systems.

Related Standards

IEC 62074-1 is part of the IEC family addressing fibre optic interconnecting devices and passive components. It references and interlinks with other IEC standards for measurement methods, reliability, and specific component types. Users should consult the normative references in the standard for the full conformity and test suite.

Keywords: fibre optic wavelength division multiplexing, WDM, passive WDM devices, requirements for optical, mechanical and environmental properties, IEC 62074-1.

Standards Content (Sample)

IEC 62074-1 ®
Edition 2.0 2014-02
INTERNATIONAL
STANDARD
colour
inside
Fibre optic interconnecting devices and passive components – Fibre optic
WDM devices –
Part 1: Generic specification
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IEC 62074-1 ®
Edition 2.0 2014-02
INTERNATIONAL
STANDARD
colour
inside
Fibre optic interconnecting devices and passive components – Fibre optic

WDM devices –
Part 1: Generic specification
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XA
ICS 33.180.01, 33.180.20 ISBN 978-2-8322-1379-7

– 2 – 62074-1 © IEC:2014(E)
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
3.1 Basic term definitions . 8
3.2 Component definitions . 9
3.3 Performance parameter definitions . 10
4 Requirements . 25
4.1 Classification . 25
4.1.1 General . 25
4.1.2 Type . 25
4.1.3 Style . 25
4.1.4 Variant . 26
4.1.5 Assessment level . 26
4.1.6 Normative reference extension . 27
4.2 Documentation . 27
4.2.1 Symbols . 27
4.2.2 Specification system . 27
4.2.3 Drawings . 28
4.2.4 Measurements . 29
4.2.5 Test data sheets . 29
4.2.6 Instructions for use . 29
4.3 Standardization system . 29
4.3.1 Performance standards . 29
4.3.2 Reliability standard . 30
4.3.3 Interlinking . 30
4.4 Design and construction . 31
4.4.1 Materials . 31
4.4.2 Workmanship . 31
4.5 Performance requirements . 31
4.6 Identification and marking . 31
4.6.1 General . 31
4.6.2 Variant identification number . 31
4.6.3 Component marking . 32
4.6.4 Package marking . 32
4.7 Safety . 32
Annex A (informative) Transfer matrix . 34
A.1 General . 34
A.2 Transfer matrix . 34
A.3 Transfer matrix coefficient . 35
A.4 Logarithmic transfer matrix . 35
Annex B (informative) Specific performances of WDM devices for bidirectional
transmission system (example) . 37
B.1 Generic . 37
B.2 Definition of near-end isolation and near-end crosstalk . 38
Annex C (informative) Transfer matrix as applications of WDM devices (example) . 40

62074-1 © IEC:2014(E) – 3 –
C.1 Generic . 40
C.2 Wavelength multiplexer . 40
C.3 Wavelength demultiplexer . 41
C.4 Wavelength multiplexer/demultiplexer . 42
C.5 Wavelength router. 43
C.6 Wavelength channel add/drop . 44
Annex D (informative) Example of technology of thin film filter WDM devices . 46
D.1 General . 46
D.2 Thin film filter technology . 46
D.3 Typical characteristics of thin film filter . 47
Annex E (informative) Example of technology of fibre fused WDM devices . 48
E.1 General . 48
E.2 Typical characteristics of fibre fused WDM devices . 49
Annex F (informative) Example of arrayed waveguide grating (AWGs) technology . 50
F.1 General . 50
F.2 Typical characteristics of AWG . 50
Annex G (informative) Example of FBG filter technology . 52
G.1 General . 52
G.2 Typical characteristics of FBG filter . 53
Bibliography . 54

Figure 1 – Example of a six-port device, with two input and four output ports . 8
Figure 2 – Illustration of channel wavelength range . 11
Figure 3 – Illustration of insertion loss . 12
Figure 4 – Illustration of ripple . 12
Figure 5 – Illustration of channel insertion loss variation . 13
Figure 6 – Illustration of isolation wavelength. 14
Figure 7 – Illustration of isolation wavelength range . 15
Figure 8 – Illustration of adjacent channel isolation . 16
Figure 9 – Illustration of non-adjacent channel isolation . 17
Figure 10 – Illustration of maximum adjacent channel crosstalk . 18
Figure 11 – Illustration of maximum non-adjacent channel crosstalk . 19
Figure 12 – Illustration of channel extinction ratio . 21
Figure 13 – Illustration of free spectral range . 22
Figure 14 – Illustration of polarization dependent centre wavelength (PDCW) . 23
Figure 15 – Illustration of X dB bandwidth . 25
Figure 16 – Wavelength-selective branching device . 26
Figure 17 – Wavelength-selective branching device . 26
Figure 18 – Wavelength-selective branching device . 26
Figure 19 – Wavelength-selective branching device . 26
Figure A.1 – Example of a six-port device, with two input and four output ports . 34
Figure A.2 – Illustration of transfer matrix coefficient . 35
Figure B.1 – Uni-directional and bi-directional transmission system application of a
1 x 2 DM device . 37
Figure B.2 – Illustration of a four-wavelength bidirectional system . 39

– 4 – 62074-1 © IEC:2014(E)
Figure C.1 – Example of a wavelength multiplexer . 40
Figure C.2 – Example of a wavelength demultiplexer . 41
Figure C.3 – Example of a wavelength multiplexer/demultiplexer . 42
Figure C.4 – Example of a wavelength router . 43
Figure C.5 – Example of wavelength channel add/drop . 44
Figure D.1 – Schematic configuration of a thin film filter WDM device . 46
Figure D.2 – Structure of multilayer thin film . 47
Figure D.3 – Typical characteristics of 1 510 nm and C-band WDM device using thin
film filter technology . 47
Figure E.1 – Structure of a fused bi-conical tapered 2x2 coupler . 48
Figure E.2 – Typical scheme for a fused coupler . 49
Figure E.3 – Typical characteristics of a fibre fused WDM device. 49
Figure F.1 – Basic configuration of AWG . 50
Figure F.2 – Example of AWG characteristics . 51
Figure G.1 – Usage of fibre Bragg grating filter . 52
Figure G.2 – Function and mechanism of fibre Bragg grating . 52
Figure G.3 – Example of FBG filter characteristics . 53

Table 1 – Three-level IEC specification structure . 27
Table 2 – Standards interlink matrix . 31

62074-1 © IEC:2014(E) – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC INTERCONNECTING DEVICES AND
PASSIVE COMPONENTS – FIBRE OPTIC WDM DEVICES –

Part 1: Generic specification
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
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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 62074-1 has been prepared by subcommittee SC 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition, published in 2009, and constitutes
a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) substantial updating to the definitions;
b) the addition of informative Annexes C to G, giving examples of technical information
concerning WDM devices.
– 6 – 62074-1 © IEC:2014(E)
The text of this standard is based on the following documents:
FDIS Report on voting
86B/3700/FDIS 86B/3722/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 62074 series, published under the general title Fibre optic
interconnecting devices and passive components – Fibre optic wdm devices, 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.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
62074-1 © IEC:2014(E) – 7 –
FIBRE OPTIC INTERCONNECTING DEVICES AND
PASSIVE COMPONENTS – FIBRE OPTIC WDM DEVICES –

Part 1: Generic specification
1 Scope
This part of IEC 62074 applies to fibre optic wavelength division multiplexing (WDM) devices.
These have all of the following general features:
• they are passive, in that they contain no optoelectronic or other transducing elements;
however they may use temperature control only to stabilize the device characteristics;
they exclude any optical switching functions;
• they have three or more ports for the entry and/or exit of optical power, and share optical
power among these ports in a predetermined fashion depending on the wavelength;
• the ports are optical fibres, or optical fibre connectors.
This standard establishes uniform requirements for the following:
• optical, mechanical and environmental properties.
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 60027 (all parts), Letter symbols to be used in electrical technology
IEC 60050-731, International Electrotechnical Vocabulary – Chapter 731: Optical fibre
communication
IEC 60695-11-5, Fire hazard testing – Part 11-5: Test flames – Needle-flame test method –
Apparatus, confirmatory test arrangement and guidance
IEC 60825-1, Safety of laser products – Part 1: Equipment classification and requirements
IEC 61931, Fibre optics – Terminology
ISO 129-1, Technical drawings – Indication of dimensions and tolerances – Part 1: General
principles
ISO 286-1, Geometrical product specifications (GPS) – ISO coding system for tolerances of
linear sizes – Part 1: Bases of tolerances and fits
ISO 1101, Geometrical product specifications (GPS) – Geometrical tolerancing – Tolerances
of form, orientation, location and run-out
ISO 8601, Data elements and interchange formats – Information interchange –
Representation of dates and times

– 8 – 62074-1 © IEC:2014(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-731, as well
as the following, apply.
3.1 Basic term definitions
3.1.1
port
optical fibre or optical fibre connector attached to a passive device for the entry and/or exit of
the optical power
3.1.2
transfer matrix
optical properties of a fibre optic wavelength-selective branching device can be defined in
terms of an n x n matrix of coefficients, where n is the number of ports, and the coefficients
represent the fractional optical power transferred between designated ports
Note 1 to entry: A detailed explanation of the transfer matrix is shown in Annex A. The ports are numbered
sequentially, so that the transfer matrix is developed to show all ports and all possible combinations. The port
numbering is arbitrary.
Note 2 to entry: Figure 1 below shows an example of a six-port device, with two input ports and four output ports.
This WDM device can operate as four input ports and two output ports for their reciprocity characteristics. Also, it
shall be noted that a combination of input and output port number can be selected, for example, 1 input port and 5
output ports, 3 input ports and 3 output ports and so on, especially for bi-directional transmission system
application. Refer to Annex B.

Inputs Outputs
IEC  0069/14
Figure 1 – Example of a six-port device, with two input and four output ports
Note 3 to entry: If there are four operating wavelengths, then the resulting transfer matrix becomes a 6 × 6 × 4
matrix: Optical attenuation at λ from port 1 to port 6 would use a . Return loss of port 2 at λ would use a .
1 161 4 224
Optical attenuation from port 5 to port 2 at λ would use a .
3 523
3.1.3
transfer matrix coefficient
element t of the transfer matrix
ij
Note 1 to entry: t is the number of more than or equal to zero, and less than or equal to one.
ij
Note 2 to entry: A detailed explanation is shown in Annex A.
3.1.4
logarithmic transfer matrix
transfer matrix whose matrix element a is a logarithmic value of transfer matrix element t . a
ij ij ij
is a number of positive and expressed in dB
Note 1 to entry: A detailed explanation is shown in Annex A.

62074-1 © IEC:2014(E) – 9 –
3.1.5
conducting port pair
port pair consisting of i and j where t is nominally greater than zero (ideally t is 1 and a is
ij ij ij
0) at a specified wavelength
3.1.6
isolated port pair
pair i and j consisting where t is nominally zero, and a is nominally infinite at a specified
ij ij
wavelength
3.1.7
channel
wavelength (frequency) band in which an optical signal is transmitted for a WDM device
Note 1 to entry: WDM devices have two or more channels.
3.1.8
channel spacing
centre-to-centre differences in frequency or wavelength between adjacent channels in a WDM
device
3.2 Component definitions
3.2.1
wavelength-selective branching device
passive component with three or more ports that shares optical power among its ports in a
predetermined fashion, without any amplification or other active modulation but only
depending on the wavelength, in the sense that at least two different wavelength ranges are
nominally transferred between two different pairs of ports
3.2.2
wavelength division multiplexing device
wavelength division multiplexer
WDM device
synonym for a wavelength-selective branching device
Note 1 to entry: The term of wavelength-selective device is the contrast with the term of non-wavelength-selective
branching device. The term of WDM device is frequently used.
3.2.3
dense wavelength division multiplexing device
DWDM device
WDM device which is intended to operate for a channel spacing equal or less than 1 000 GHz
(approximately 8 nm at 1 550 nm and 5,7 nm at 1 310 nm)
3.2.4
coarse wavelength division multiplexing device
CWDM device
WDM device which is intended to operate for channel spacing less than 50 nm and greater
than 1 000 GHz
3.2.5
wide WDM device
WWDM
WDM device which is intended to operate for channel spacing equal to or greater than 50 nm

– 10 – 62074-1 © IEC:2014(E)
3.2.6
wavelength multiplexer
MUX
WDM (DWDM, CWDM or WWDM) device which has n input ports and one output port, and
whose function is to combine n different optical signals differentiated by wavelength from n
corresponding input ports on to a single output port
3.2.7
wavelength demultiplexer
DEMUX
WDM (DWDM, CWDM or WWDM) device which has one input port and n output ports, and
whose function is to separate n different optical signals differentiated by wavelength from a
single input port to n corresponding output ports
3.2.8
interleaver
DWDM device which has three ports, and which function is to separate n different optical
signals differentiated by wavelength from a common port and transmit an odd channel signal
to one branching port and an even channel signal to the other branching port alternately
Note 1 to entry: An interleaver can operate as a wavelength multiplexer (OMUX) by reversing the demultiplexer.
3.3 Performance parameter definitions
3.3.1
operating wavelength
nominal wavelength λ at which a WDM device operates with the specified performance
h
Note 1 to entry: The term "operating wavelength" includes the wavelength to be nominally transmitting,
designated attenuating and isolated.
Note 2 to entry: Operating frequency is also used for DWDM devices.
3.3.2
operating wavelength range
specified range of wavelengths including all operating wavelengths
Note 1 to entry: It includes all passbands and isolation wavelength ranges corresponding to all channels.
Note 2 to entry: The term "operating wavelength range" is defined for a WDM device, not for each channel or port.
3.3.3
channel wavelength range
range within which a CWDM or WWDM device operates with less than or equal to a specified
optical attenuation for the conducting port pair
Note 1 to entry: For a particular nominal channel centre wavelength, λ , this wavelength range from λ =
nom imin
(λ - Δλ ) to λ = (λ + Δλ ), where Δλ is the maximum channel centre wavelength deviation.
nom max imax nom max max
Note 2 to entry: For CWDM devices, channel centre wavelengths and maximum channel centre wavelength
deviations are defined as nominal central wavelengths and wavelength deviations in ITU-T. G 694.2.
Note 3 to entry: An illustration of channel wavelength range is shown in Figure 2.

62074-1 © IEC:2014(E) – 11 –
Channel
wavelength
Channel
rangefor a
ij
wavelength
channel h
range for
a
channel k
im
λ
λ
k
h
λ λ λ λ
hmin hmax kmin kmax
Wavelength
IEC  0070/14
Figure 2 – Illustration of channel wavelength range
3.3.4
channel frequency range
frequency range within which a DWDM device is required to operate with less than or equal to
a specified optical attenuation for the conducting port pair
Note 1 to entry: For a particular nominal channel frequency, f , this frequency range is from f = (f -
nomi imin nomi
Δf ) to = (f + Δf ), where Δf is the maximum channel centre frequency deviation.
max fimax nomi max max
Note 2 to entry: Nominal channel centre frequency and maximum channel centre frequency deviation are defined
in ITU-T. G.694.1.
3.3.5
passband
channel passband
synonym for channel wavelength range (channel frequency range)
Note 1 to entry: Passband is frequently used.
Note 2 to entry: There are two or more passbands for WDM devices. Each passband is defined corresponding to
each channel.
3.3.6
insertion loss
maximum value of a (where i ≠ j) within the passband for conducting port pair

ij
Note 1 to entry: It is the optical attenuation from a given port to a port which is another port of conducting port
pair of the given port of a WDM device. Insertion loss is a positive value in decibels. It is calculated as:
 
P
out
IL = −10log 
 
P
 in 
where
P is the optical power launched into the port;
in
P is the optical power received from the other port of the conducting port pair.
out
Note 2 to entry: An illustration of insertion loss is shown in Figure 3.
Optical attenuation  (dB)
– 12 – 62074-1 © IEC:2014(E)
Passband
for
Passband
a
channel h
ij
for
channel k
a
im
λ
λ
h k
λ λ
λ λ
kmin kmax Wavelength
hmin hmax
IEC  0071/14
Figure 3 – Illustration of insertion loss
Note 3 to entry: For a WDM device, the insertion loss shall be specified as a maximum value of the insertion
losses of all channels
3.3.7
channel insertion loss
term used for WDM devices which has a similar same meaning as insertion loss except that
channel insertion loss is used for a channel whereas insertion loss is used in the
specifications of both a WDM device and for a channel
3.3.8
passband ripple
maximum peak-to-peak variation of the insertion loss (absolute value) over the passband
(within a channel frequency or wavelength range) (refer to Figure 4 below)

Channel frequency Channel frequency
(or wavelength) range (or wavelength) range

Ripple
Ripple
Frequency (or wavelength)
IEC  0072/14
Figure 4a – Ripple at band edges Figure 4b – Ripple in band
Figure 4 – Illustration of ripple
Optical attenuation  (dB)
Optical attenuation  (dB)
Maximum insertion loss
for channel h
Maximum insertion loss
for channel k
62074-1 © IEC:2014(E) – 13 –
3.3.9
maximum channel insertion loss deviation
maximum variation of the insertion loss (absolute value) within the passband (channel
frequency range for a DWDM device or channel wavelength range for a coarse WDM (CWDM)
and a wide WDM (WWDM) device) (See Figure 5)
Note 1 to entry: Channel insertion loss deviation should not to be confused with ripple defined in Figure 5 below.

Channel centre frequency
(or wavelength)
Channel frequency range for DWDM
devices, channel wavelength range for
CWDM and WWDM devices)
Insertion loss
Maximum channel
characteristics for three
insertion loss
temperatures deviation
Frequency (THz) for DWDM devices, wavelength (nm) for CWDM and WWDM devices
IEC  0073/14
Figure 5 – Illustration of channel insertion loss variation
3.3.10
channel non-uniformity
insertion loss channel non-uniformity
for a specified set of branching ports the difference between the maximum and the minimum
insertion loss at the common port
Note 1 to entry: Channel non-uniformity is defined for a MUX (N x 1 WDM device) and a DEMUX (1 x N WDM
device). Channel non-uniformity is a positive value, and expressed in dB.
Note 2 to entry: For CWDM and DWDM devices, channel non-uniformity should be defined as the differences
between the maximum and the minimum insertion loss at nominal wavelengths (frequencies) of all channels.
3.3.11
centre wavelength deviation
difference between the centre wavelength and nominal wavelength (frequency) of the
specified channel for DWDM devices, where the centre wavelength is defined as the centre of
the wavelength range which is x dB less than the minimum optical attenuation for the
specified passband (channel)
Note 1 to entry: 0,5, 1 or 3 are generally used for x.
Optical attenuation  (dB)
– 14 – 62074-1 © IEC:2014(E)
3.3.12
crosstalk
for WDM devices, the value of the ratio between the optical power of the specified signal and
the specified noise
Note 1 to entry: Crosstalk is a negative value given in dB. The crosstalk is defined for each output port. Crosstalk
for WDM devices is defined for a DEMUX (1 x N WDM device). The crosstalk for port o to port j is subtraction from
the insertion loss of port i to o (conducting port pair) to the isolation of port j to o (isolated port pair). Crosstalk for
WDM devices is defined for a DEMUX (1 x N WDM device). For an MxN WDM device, crosstalk can be defined to
as expanding M of a 1 x N WDM device.
Note 2 to entry: For WDM devices with three of more ports, the crosstalk should be specified as the maximum
value of the crosstalk for each output port.
Note 3 to entry: Care should be taken not to confuse crosstalk and isolation.
3.3.13
isolation
minimum value of a (where i ≠ j) within isolation wavelength range for isolated port pair
ij
Note 1 to entry: Isolation is a positive value expressed in dB.
3.3.14
isolation wavelength
λ , a
for a pair of ports i and j (where i ≠ j), that are conducting port pair at a wavelength
h
nominal wavelength λ (where λ ≠ λ ), that is an operating wavelength for a different pair of
k h k
ports, at which i and j are isolated port pair (refer to Figure 6 below)
Note 1 to entry: Isolation frequency is also used for DWDM device.
a
ij
a
im
λ λ
h k
Wavelength
Isolation wavelength
Operating
wavelength
IEC  0074/14
Figure 6 – Illustration of isolation wavelength
3.3.15
isolation wavelength range
for a pair of ports i and j that are a conducting port pair at wavelength λ , the range of
h
wavelengths from λ to λ centred about an operating wavelength λ that is an
kmin kmax k
operating wavelength for a different pair of ports but at which i and j are an isolated port pair
(refer to Figure 7 below)
Note 1 to entry: Isolation frequency range is also used for DWDM devices.
Optical attenuation  (dB)
62074-1 © IEC:2014(E) – 15 –
a
ij
a
im
λ λ
k
h
λ
λ
kmin kmax
Wavelength
Isolation wavelength range
IEC  0075/14
Figure 7 – Illustration of isolation wavelength range
3.3.16
wavelength isolation
value of a (where i ≠ j) in the isolation wavelength range
ij
Note 1 to entry: The wavelength isolation shall be defined as the minimum value of wavelength isolation over the
isolation wavelength range.
3.3.17
adjacent channel isolation
isolation with the restriction that x, the isolation wavelength number, is restricted to the
channels immediately adjacent to the (channel) wavelength number associated with port o
Note 1 to entry: Adjacent channel isolation is a positive value expressed in dB
Note 2 to entry: This is illustrated in Figure 8 below. The adjacent channel isolation is different from adjacent
channel crosstalk. In Figure 8, the upward-pointing arrow indicates a positive value, and the downward-pointing
arrow indicates a negative value. Generally, there are two adjacent channel isolations for the shorter wavelength
(higher frequency) side and the longer wavelength (lower frequency) side.
3.3.18
adjacent channel crosstalk
crosstalk with the restriction that x, the isolation wavelength number, is restricted to the
channels immediately adjacent to the (channel) wavelength number associated with port o
Note 1 to entry: Adjacent channel crosstalk is a negative value expressed in dB.
Note 2 to entry: This is illustrated in Figure 8 below. Adjacent channel crosstalk is different from adjacent channel
isolation. In Figure 8, the upward-pointing arrow indicates a positive value, and the downward-pointing arrow
indicates a negative value. Generally, there are two adjacent channel crosstalks for the shorter wavelength (higher
frequency) side and the longer wavelength (lower frequency) side.
Optical attenuation  (dB)
– 16 – 62074-1 © IEC:2014(E)
Non-adjacent Adjacent channel Adjacent channel Non-adjacent
Channel centre
channel centre centre frequency frequency centre frequency channel centre
frequency (wavelength) (wavelength) (wavelength) frequency
(wavelength)  (wavelength)
a
iox
a
ioc
Frequency (THz) for DWDM devices, wavelength (nm) for CWDM and WWDM devices

IEC  0076/14
Figure 8 – Illustration of adjacent channel isolation
3.3.19
non-adjacent channel isolation
isolation with the restriction that the isolation wavelength (frequency) is restricted to each of
the channels not immediately adjacent to the channel associated with port o (refer to Figure 9
below)
Note 1 to entry: The non-adjacent channel isolation is different from non-adjacent channel crosstalk. In Figure 9,
the upward-pointing arrow indicates a positive value, and the downward-pointing arrow indicates a negative value.
3.3.20
non-adjacent channel crosstalk
crosstalk where the isolation wavelength (frequency) is restricted to each of the channels not
immediately adjacent to the channel associated with port o (refer to Figure 9 below)
Note 1 to entry: Non-adjacent channel crosstalk is different from non-adjacent channel isolation. In Figure 9, the
upward-pointing arrow indicates a positive value, and the downward-pointing arrow indicates a negative value.
Optical attenuation  (dB)
Adjacent channel isolation
Adjacent channel crosstalk
62074-1 © IEC:2014(E) – 17 –
Non-adjacent Adjacent channel Adjacent channel Non-adjacent
Channel centre
channel centre centre frequency centre frequency channel centre
frequency
frequency (wavelength) (wavelength) (wavelength) frequency
(wavelength)  (wavelength)
a
iox
a
ioc
Frequency (THz) for DWDM devices, wavelength (nm) for CWDM and WWDM devices

IEC  0077/14
Figure 9 – Illustration of non-adjacent channel isolation
3.3.21
minimum adjacent channel isolation
minimum value of a within the adjacent operating wavelength (or frequency) range (adjacent
ij
channel passband). The minimum adjacent channel isolation is positive in dB
Note 1 to entry: Refer to Figure 10 below. Generally, there are two minimum adjacent channel isolations. For a
channel, the minimum value of two minimum adjacent channel isolations is selected.
Note 2 to entry: The minimum adjacent channel isolation is different from the maximum adjacent channel
crosstalk. In Figure 10, the upward-pointing arrow indicates a positive value, and the downward-pointing arrow
indicates a negative value.
3.3.22
maximum adjacent channel crosstalk
maximum value of adjacent channel crosstalk within adjacent channel wavelength (frequency)
range (adjacent channel passband)
Note 1 to entry: This is the maximum value of the subtraction from the maximum insertion loss to the minimum
adjacent isolation. Maximum adjacent channel crosstalk is negative value in dB. Refer to Figure 10 below.
Generally, there are two maximum adjacent channel crosstalks. For a channel, the maximum value of two
maximum adjacent channel crosstalks is selected.
Note 2 to entry: The maximum adjacent channel crosstalk is different from the minimum adjacent channel
isolation. In Figure 10, the upward-pointing arrow indicates a positive value, and the downward-pointing arrow
indicates a negative value.
Optical attenuation  (dB)
Non-adjacent channel isolation
Non-adjacent channel crosstalk

– 18 – 62074-1 © IEC:2014(E)
Non-adjacent Adjacent channel Channel centre Adjacent channel Non-adjacent
channel centre centre frequency centre frequency channel centre
frequency
frequency (wavelength) (wavelength) frequency
(wavelength)
(wavelength) (wavelength)
Adjacent channel
Non-adjacent Adjacent Channel centre Non-adjacent
frequency
channel channel frequency channel
(wavelength)
frequency frequency (wavelength) frequency
range
(wavelength) (wavelength) range (wavelength)
range range range
a
ioc
a
iox
Frequency (THz) for DWDM devices, wavelength (nm) for CWDM and WWDM devices

IEC  0078/14
Figure 10 – Illustration of maximum adjacent channel crosstalk
3.3.23
minimum non-adjacent channel isolation
minimum difference between the minimum peak of a in the operating wavelength (or
ij
frequency) range and the maximum value of a in a specified range of wavelengths (or
ij
frequencies) from λ to λ centred about an isolation wavelength (or frequency) λ for
kmin kmax k
any two ports i and j, λ and λ defining an operating wavelength (or frequency) range
kmin kmax
for a different pair of ports for which λ is an operating wavelength (or frequency) (refer to
k
Figure 11 below).
Note 1 to entry: The minimum adjacent channel isolation is different from the maximum adjacent channel
crosstalk. In Figure 10, the upward-pointing arrow indicates a positive value, and the down-pointing arrow indicates
a negative value.
3.3.24
maximum non-adjacent channel crosstalk
minimum difference between the minimum peak of a in the operating wavelength (or
ij
frequency) ra
...

IEC 62074-1 ®
Edition 2.0 2014-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Fibre optic interconnecting devices and passive components – Fibre optic WDM
devices –
Part 1: Generic specification
Dispositifs d’interconnexion et composants passifs à fibres optiques –
Dispositifs WDM à fibres optiques –
Partie 1: Spécification générique

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IEC 62074-1 ®
Edition 2.0 2014-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Fibre optic interconnecting devices and passive components – Fibre optic WDM

devices –
Part 1: Generic specification
Dispositifs d’interconnexion et composants passifs à fibres optiques –

Dispositifs WDM à fibres optiques –

Partie 1: Spécification générique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.01 ; 33.180.20 ISBN 978-2-8322-3141-8

– 2 – IEC 62074-1:2014  IEC 2014
CONTENTS
FOREWORD. 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
3.1 Basic term definitions . 8
3.2 Component definitions . 9
3.3 Performance parameter definitions . 10
4 Requirements . 25
4.1 Classification . 25
4.1.1 General . 25
4.1.2 Type . 25
4.1.3 Style . 26
4.1.4 Variant . 27
4.1.5 Assessment level . 27
4.1.6 Normative reference extension . 28
4.2 Documentation . 28
4.2.1 Symbols . 28
4.2.2 Specification system . 28
4.2.3 Drawings . 29
4.2.4 Measurements . 29
4.2.5 Test data sheets. 29
4.2.6 Instructions for use . 30
4.3 Standardization system . 30
4.3.1 Performance standards . 30
4.3.2 Reliability standard . 30
4.3.3 Interlinking . 31
4.4 Design and construction . 31
4.4.1 Materials . 31
4.4.2 Workmanship . 31
4.5 Performance requirements . 32
4.6 Identification and marking . 32
4.6.1 General . 32
4.6.2 Variant identification number . 32
4.6.3 Component marking . 32
4.6.4 Package marking . 32
4.7 Safety . 33
Annex A (informative) Transfer matrix . 34
A.1 General . 34
A.2 Transfer matrix . 34
A.3 Transfer matrix coefficient . 35
A.4 Logarithmic transfer matrix . 35
Annex B (informative) Specific performances of WDM devices for bidirectional
transmission system (example) . 37
B.1 Generic . 37
B.2 Definition of near-end isolation and near-end crosstalk . 38
Annex C (informative) Transfer matrix as applications of WDM devices (example) . 40

C.1 Generic . 40
C.2 Wavelength multiplexer . 40
C.3 Wavelength demultiplexer . 41
C.4 Wavelength multiplexer/demultiplexer . 42
C.5 Wavelength router . 43
C.6 Wavelength channel add/drop . 44
Annex D (informative) Example of technology of thin film filter WDM devices . 46
D.1 General . 46
D.2 Thin film filter technology . 46
D.3 Typical characteristics of thin film filter . 47
Annex E (informative) Example of technology of fibre fused WDM devices . 48
E.1 General . 48
E.2 Typical characteristics of fibre fused WDM devices . 49
Annex F (informative) Example of arrayed waveguide grating (AWGs) technology . 50
F.1 General . 50
F.2 Typical characteristics of AWG . 50
Annex G (informative) Example of FBG filter technology . 52
G.1 General . 52
G.2 Typical characteristics of FBG filter . 53
Bibliography . 54

Figure 1 – Example of a six-port device, with two input and four output ports . 8
Figure 2 – Illustration of channel wavelength range . 11
Figure 3 – Illustration of insertion loss . 12
Figure 4 – Illustration of ripple . 12
Figure 5 – Illustration of channel insertion loss variation . 13
Figure 6 – Illustration of isolation wavelength . 14
Figure 7 – Illustration of isolation wavelength range . 15
Figure 8 – Illustration of adjacent channel isolation . 16
Figure 9 – Illustration of non-adjacent channel isolation . 17
Figure 10 – Illustration of maximum adjacent channel crosstalk . 18
Figure 11 – Illustration of maximum non-adjacent channel crosstalk . 19
Figure 12 – Illustration of channel extinction ratio . 21
Figure 13 – Illustration of free spectral range . 22
Figure 14 – Illustration of polarization dependent centre wavelength (PDCW). 23
Figure 15 – Illustration of X dB bandwidth . 25
Figure 16 – Wavelength-selective branching device . 26
Figure 17 – Wavelength-selective branching device . 26
Figure 18 – Wavelength-selective branching device . 26
Figure 19 – Wavelength-selective branching device . 27
Figure A.1 – Example of a six-port device, with two input and four output ports . 34
Figure A.2 – Illustration of transfer matrix coefficient . 35
Figure B.1 – Uni-directional and bi-directional transmission system application
of a 1 × 2 DM device . 37
Figure B.2 – Illustration of a four-wavelength bidirectional system . 39

– 4 – IEC 62074-1:2014  IEC 2014
Figure C.1 – Example of a wavelength multiplexer . 40
Figure C.2 – Example of a wavelength demultiplexer . 41
Figure C.3 – Example of a wavelength multiplexer/demultiplexer . 42
Figure C.4 – Example of a wavelength router . 43
Figure C.5 – Example of wavelength channel add/drop . 44
Figure D.1 – Schematic configuration of a thin film filter WDM device . 46
Figure D.2 – Structure of multilayer thin film . 47
Figure D.3 – Typical characteristics of 1 510 nm and C-band WDM device using thin
film filter technology . 47
Figure E.1 – Structure of a fused bi-conical tapered 2x2 coupler . 48
Figure E.2 – Typical scheme for a fused coupler . 49
Figure E.3 – Typical characteristics of a fibre fused WDM device . 49
Figure F.1 – Basic configuration of AWG . 50
Figure F.2 – Example of AWG characteristics . 51
Figure G.1 – Usage of fibre Bragg grating filter . 52
Figure G.2 – Function and mechanism of fibre Bragg grating . 52
Figure G.3 – Example of FBG filter characteristics . 53

Table 1 – Three-level IEC specification structure . 28
Table 2 – Standards interlink matrix . 31

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
FIBRE OPTIC INTERCONNECTING DEVICES AND
PASSIVE COMPONENTS – FIBRE OPTIC WDM DEVICES –

Part 1: Generic specification
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
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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6) All users should ensure that they have the latest edition of this publication.
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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 62074-1 has been prepared by subcommittee SC 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition, published in 2009, and constitutes
a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) substantial updating to the definitions;
b) the addition of informative Annexes C to G, giving examples of technical information
concerning WDM devices.
– 6 – IEC 62074-1:2014  IEC 2014
This bilingual version (2016-01) corresponds to the monolingual English version, published in
2014-02.
The text of this standard is based on the following documents:
FDIS Report on voting
86B/3700/FDIS 86B/3722/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 62074 series, published under the general title Fibre optic
interconnecting devices and passive components – Fibre optic wdm devices, can be found on
the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
FIBRE OPTIC INTERCONNECTING DEVICES AND
PASSIVE COMPONENTS – FIBRE OPTIC WDM DEVICES –

Part 1: Generic specification
1 Scope
This part of IEC 62074 applies to fibre optic wavelength division multiplexing (WDM) devices.
These have all of the following general features:
• they are passive, in that they contain no optoelectronic or other transducing elements;
however they may use temperature control only to stabilize the device characteristics;
they exclude any optical switching functions;
• they have three or more ports for the entry and/or exit of optical power, and share optical
power among these ports in a predetermined fashion depending on the wavelength;
• the ports are optical fibres, or optical fibre connectors.
This standard establishes uniform requirements for the following:
• optical, mechanical and environmental properties.
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 60027 (all parts), Letter symbols to be used in electrical technology
IEC 60050-731, International Electrotechnical Vocabulary – Chapter 731: Optical fibre
communication
IEC 60695-11-5, Fire hazard testing – Part 11-5: Test flames – Needle-flame test method –
Apparatus, confirmatory test arrangement and guidance
IEC 60825-1, Safety of laser products – Part 1: Equipment classification and requirements
IEC 61931, Fibre optics – Terminology
ISO 129-1, Technical drawings – Indication of dimensions and tolerances – Part 1: General
principles
ISO 286-1, Geometrical product specifications (GPS) – ISO coding system for tolerances of
linear sizes – Part 1: Bases of tolerances and fits
ISO 1101, Geometrical product specifications (GPS) – Geometrical tolerancing – Tolerances
of form, orientation, location and run-out
ISO 8601, Data elements and interchange formats – Information interchange –
Representation of dates and times

– 8 – IEC 62074-1:2014  IEC 2014
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-731, as well
as the following, apply.
3.1 Basic term definitions
3.1.1
port
optical fibre or optical fibre connector attached to a passive device for the entry and/or exit of
the optical power
3.1.2
transfer matrix
optical properties of a fibre optic wavelength-selective branching device can be defined in
terms of an n × n matrix of coefficients, where n is the number of ports, and the coefficients
represent the fractional optical power transferred between designated ports
Note 1 to entry: A detailed explanation of the transfer matrix is shown in Annex A. The ports are numbered
sequentially, so that the transfer matrix is developed to show all ports and all possible combinations. The port
numbering is arbitrary.
Note 2 to entry: Figure 1 below shows an example of a six-port device, with two input ports and four output ports.
This WDM device can operate as four input ports and two output ports for their reciprocity characteristics. Also, it
shall be noted that a combination of input and output port number can be selected, for example, 1 input port and 5
output ports, 3 input ports and 3 output ports and so on, especially for bi-directional transmission system
application. Refer to Annex B.

Inputs Outputs
IEC  0069/14
Figure 1 – Example of a six-port device, with two input and four output ports
Note 3 to entry: If there are four operating wavelengths, then the resulting transfer matrix becomes a 6 × 6 × 4
matrix: Optical attenuation at l from port 1 to port 6 would use a . Return loss of port 2 at l would use a .
1 161 4 224
Optical attenuation from port 5 to port 2 at l would use a .
3 523
3.1.3
transfer matrix coefficient
element t of the transfer matrix
ij
Note 1 to entry: t is the number of more than or equal to zero, and less than or equal to one.
ij
Note 2 to entry: A detailed explanation is shown in Annex A.
3.1.4
logarithmic transfer matrix
transfer matrix whose matrix element a is a logarithmic value of transfer matrix element t . a
ij ij ij
is a number of positive and expressed in dB
Note 1 to entry: A detailed explanation is shown in Annex A.

3.1.5
conducting port pair
port pair consisting of i and j where t is nominally greater than zero (ideally t is 1 and a is
ij ij ij
0) at a specified wavelength
3.1.6
isolated port pair
pair i and j consisting where t is nominally zero, and a is nominally infinite at a specified
ij ij
wavelength
3.1.7
channel
wavelength (frequency) band in which an optical signal is transmitted for a WDM device
Note 1 to entry: WDM devices have two or more channels.
3.1.8
channel spacing
centre-to-centre differences in frequency or wavelength between adjacent channels in a WDM
device
3.2 Component definitions
3.2.1
wavelength-selective branching device
passive component with three or more ports that shares optical power among its ports in a
predetermined fashion, without any amplification or other active modulation but only
depending on the wavelength, in the sense that at least two different wavelength ranges are
nominally transferred between two different pairs of ports
3.2.2
wavelength division multiplexing device
wavelength division multiplexer
WDM device
synonym for a wavelength-selective branching device
Note 1 to entry: The term of wavelength-selective device is the contrast with the term of non-wavelength-selective
branching device. The term of WDM device is frequently used.
3.2.3
dense wavelength division multiplexing device
DWDM device
WDM device which is intended to operate for a channel spacing equal or less than 1 000 GHz
(approximately 8 nm at 1 550 nm and 5,7 nm at 1 310 nm)
3.2.4
coarse wavelength division multiplexing device
CWDM device
WDM device which is intended to operate for channel spacing less than 50 nm and greater
than 1 000 GHz
3.2.5
wide WDM device
WWDM
WDM device which is intended to operate for channel spacing equal to or greater than 50 nm

– 10 – IEC 62074-1:2014  IEC 2014
3.2.6
wavelength multiplexer
MUX
WDM (DWDM, CWDM or WWDM) device which has n input ports and one output port, and
whose function is to combine n different optical signals differentiated by wavelength from n
corresponding input ports on to a single output port
3.2.7
wavelength demultiplexer
DEMUX
WDM (DWDM, CWDM or WWDM) device which has one input port and n output ports, and
whose function is to separate n different optical signals differentiated by wavelength from a
single input port to n corresponding output ports
3.2.8
interleaver
DWDM device which has three ports, and which function is to separate n different optical
signals differentiated by wavelength from a common port and transmit an odd channel signal
to one branching port and an even channel signal to the other branching port alternately
Note 1 to entry: An interleaver can operate as a wavelength multiplexer (OMUX) by reversing the demultiplexer.
3.3 Performance parameter definitions
3.3.1
operating wavelength
nominal wavelength l at which a WDM device operates with the specified performance
h
Note 1 to entry: The term "operating wavelength" includes the wavelength to be nominally transmitting,
designated attenuating and isolated.
Note 2 to entry: Operating frequency is also used for DWDM devices.
3.3.2
operating wavelength range
specified range of wavelengths including all operating wavelengths
Note 1 to entry: It includes all passbands and isolation wavelength ranges corresponding to all channels.
Note 2 to entry: The term "operating wavelength range" is defined for a WDM device, not for each channel or port.
3.3.3
channel wavelength range
range within which a CWDM or WWDM device operates with less than or equal to a specified
optical attenuation for the conducting port pair
Note 1 to entry: For a particular nominal channel centre wavelength, l , this wavelength range from l =
nom imin
(l − ∆l ) to l = (l + ∆l ), where ∆l is the maximum channel centre wavelength deviation.
nom max imax nom max max
Note 2 to entry: For CWDM devices, channel centre wavelengths and maximum channel centre wavelength
deviations are defined as nominal central wavelengths and wavelength deviations in ITU-T. G 694.2.
Note 3 to entry: An illustration of channel wavelength range is shown in Figure 2.

Channel
wavelength
Channel
a
rangefor
ij
wavelength
channel h
range for
a
channel k im
l
l
k
h
l l
l l
hmin hmax kmin kmax
Wavelength
IEC  0070/14
Figure 2 – Illustration of channel wavelength range
3.3.4
channel frequency range
frequency range within which a DWDM device is required to operate with less than or equal to
a specified optical attenuation for the conducting port pair
Note 1 to entry: For a particular nominal channel frequency, f , this frequency range is from f =
nomi imin
(f ∆f ) to = (f + ∆f ), where ∆f is the maximum channel centre frequency deviation.
nomi − max fimax nomi max max
Note 2 to entry: Nominal channel centre frequency and maximum channel centre frequency deviation are defined
in ITU-T. G.694.1.
3.3.5
passband
channel passband
synonym for channel wavelength range (channel frequency range)
Note 1 to entry: Passband is frequently used.
Note 2 to entry: There are two or more passbands for WDM devices. Each passband is defined corresponding to
each channel.
3.3.6
insertion loss
maximum value of a (where i ≠ j) within the passband for conducting port pair

ij
Note 1 to entry: It is the optical attenuation from a given port to a port which is another port of conducting port
pair of the given port of a WDM device. Insertion loss is a positive value in decibels. It is calculated as:
 P 
out
IL = −10log 
 
P
 in 
where
P is the optical power launched into the port;
in
P is the optical power received from the other port of the conducting port pair.
out
Note 2 to entry: An illustration of insertion loss is shown in Figure 3.
Optical attenuation  (dB)
– 12 – IEC 62074-1:2014  IEC 2014

Passband
for
Passband
a
channel h
ij
for
channel k
a
im
l
l
k
h
l l
l l
kmin kmax Wavelength
hmin hmax
IEC  0071/14
Figure 3 – Illustration of insertion loss
Note 3 to entry: For a WDM device, the insertion loss shall be specified as a maximum value of the insertion
losses of all channels
3.3.7
channel insertion loss
term used for WDM devices which has a similar same meaning as insertion loss except that
channel insertion loss is used for a channel whereas insertion loss is used in the
specifications of both a WDM device and for a channel
3.3.8
passband ripple
maximum peak-to-peak variation of the insertion loss (absolute value) over the passband
(within a channel frequency or wavelength range) (refer to Figure 4 below)

Channel frequency Channel frequency
(or wavelength) range (or wavelength) range

Ripple
Ripple
Frequency (or wavelength)
IEC  0072/14
Figure 4a – Ripple at band edges Figure 4b – Ripple in band
Figure 4 – Illustration of ripple
Optical attenuation  (dB)
Optical attenuation  (dB)
Maximum insertion loss
for channel h
Maximum insertion loss
for channel k
3.3.9
maximum channel insertion loss deviation
maximum variation of the insertion loss (absolute value) within the passband (channel
frequency range for a DWDM device or channel wavelength range for a coarse WDM (CWDM)
and a wide WDM (WWDM) device) (See Figure 5)
Note 1 to entry: Channel insertion loss deviation should not to be confused with ripple defined in Figure 5 below.

Channel centre frequency
(or wavelength)
Channel frequency range for DWDM
devices, channel wavelength range for
CWDM and WWDM devices)
Insertion loss Maximum channel
characteristics for three
insertion loss
temperatures
deviation
Frequency (THz) for DWDM devices, wavelength (nm) for CWDM and WWDM devices
IEC  0073/14
Figure 5 – Illustration of channel insertion loss variation
3.3.10
channel non-uniformity
insertion loss channel non-uniformity
for a specified set of branching ports the difference between the maximum and the minimum
insertion loss at the common port
Note 1 to entry: Channel non-uniformity is defined for a MUX (N × 1 WDM device) and a DEMUX (1 × N WDM
device). Channel non-uniformity is a positive value, and expressed in dB.
Note 2 to entry: For CWDM and DWDM devices, channel non-uniformity should be defined as the differences
between the maximum and the minimum insertion loss at nominal wavelengths (frequencies) of all channels.
3.3.11
centre wavelength deviation
difference between the centre wavelength and nominal wavelength (frequency) of the
specified channel for DWDM devices, where the centre wavelength is defined as the centre of
the wavelength range which is x dB less than the minimum optical attenuation for the specified
passband (channel)
Note 1 to entry: 0,5, 1 or 3 are generally used for x.
Optical attenuation  (dB)
– 14 – IEC 62074-1:2014  IEC 2014
3.3.12
crosstalk
for WDM devices, the value of the ratio between the optical power of the specified signal and
the specified noise
Note 1 to entry: Crosstalk is a negative value given in dB. The crosstalk is defined for each output port. Crosstalk
for WDM devices is defined for a DEMUX (1 × N WDM device). The crosstalk for port o to port j is subtraction from
the insertion loss of port i to o (conducting port pair) to the isolation of port j to o (isolated port pair). Crosstalk for
WDM devices is defined for a DEMUX (1 × N WDM device). For an MxN WDM device, crosstalk can be defined to
as expanding M of a 1 × N WDM device.
Note 2 to entry: For WDM devices with three of more ports, the crosstalk should be specified as the maximum
value of the crosstalk for each output port.
Note 3 to entry: Care should be taken not to confuse crosstalk and isolation.
3.3.13
isolation
minimum value of a (where i ≠ j) within isolation wavelength range for isolated port pair
ij
Note 1 to entry: Isolation is a positive value expressed in dB.
3.3.14
isolation wavelength
for a pair of ports i and j (where i ≠ j), that are conducting port pair at a wavelength l , a
h
nominal wavelength l (where l ≠ l ), that is an operating wavelength for a different pair of
k h k
ports, at which i and j are isolated port pair (refer to Figure 6 below)
Note 1 to entry: Isolation frequency is also used for DWDM device.
a
ij
a
im
l l
k
h
Wavelength
Operating Isolation wavelength
wavelength
IEC  0074/14
Figure 6 – Illustration of isolation wavelength
3.3.15
isolation wavelength range
for a pair of ports i and j that are a conducting port pair at wavelength l , the range of
h
wavelengths from l to l centred about an operating wavelength l that is an
kmin kmax k
operating wavelength for a different pair of ports but at which i and j are an isolated port pair
(refer to Figure 7 below)
Note 1 to entry: Isolation frequency range is also used for DWDM devices.
Optical attenuation  (dB)
a
ij
a
im
l l
k
h
l l
kmin
kmax
Wavelength
Isolation wavelength range
IEC  0075/14
Figure 7 – Illustration of isolation wavelength range
3.3.16
wavelength isolation
value of a (where i ≠ j) in the isolation wavelength range
ij
Note 1 to entry: The wavelength isolation shall be defined as the minimum value of wavelength isolation over the
isolation wavelength range.
3.3.17
adjacent channel isolation
isolation with the restriction that x, the isolation wavelength number, is restricted to the
channels immediately adjacent to the (channel) wavelength number associated with port o
Note 1 to entry: Adjacent channel isolation is a positive value expressed in dB
Note 2 to entry: This is illustrated in Figure 8 below. The adjacent channel isolation is different from adjacent
channel crosstalk. In Figure 8, the upward-pointing arrow indicates a positive value, and the downward-pointing
arrow indicates a negative value. Generally, there are two adjacent channel isolations for the shorter wavelength
(higher frequency) side and the longer wavelength (lower frequency) side.
3.3.18
adjacent channel crosstalk
crosstalk with the restriction that x, the isolation wavelength number, is restricted to the
channels immediately adjacent to the (channel) wavelength number associated with port o
Note 1 to entry: Adjacent channel crosstalk is a negative value expressed in dB.
Note 2 to entry: This is illustrated in Figure 8 below. Adjacent channel crosstalk is different from adjacent channel
isolation. In Figure 8, the upward-pointing arrow indicates a positive value, and the downward-pointing arrow
indicates a negative value. Generally, there are two adjacent channel crosstalks for the shorter wavelength (higher
frequency) side and the longer wavelength (lower frequency) side.
Optical attenuation  (dB)
– 16 – IEC 62074-1:2014  IEC 2014
Non-adjacent Adjacent channel Adjacent channel Non-adjacent
Channel centre
channel centre centre frequency frequency centre frequency channel centre
frequency (wavelength) (wavelength) (wavelength) frequency
(wavelength)  (wavelength)
a
iox
a
ioc
Frequency (THz) for DWDM devices, wavelength (nm) for CWDM and WWDM devices

IEC  0076/14
Figure 8 – Illustration of adjacent channel isolation
3.3.19
non-adjacent channel isolation
isolation with the restriction that the isolation wavelength (frequency) is restricted to each of
the channels not immediately adjacent to the channel associated with port o (refer to Figure 9
below)
Note 1 to entry: The non-adjacent channel isolation is different from non-adjacent channel crosstalk. In Figure 9,
the upward-pointing arrow indicates a positive value, and the downward-pointing arrow indicates a negative value.
3.3.20
non-adjacent channel crosstalk
crosstalk where the isolation wavelength (frequency) is restricted to each of the channels not
immediately adjacent to the channel associated with port o (refer to Figure 9 below)
Note 1 to entry: Non-adjacent channel crosstalk is different from non-adjacent channel isolation. In Figure 9, the
upward-pointing arrow indicates a positive value, and the downward-pointing arrow indicates a negative value.
Optical attenuation  (dB)
Adjacent channel isolation
Adjacent channel crosstalk
Non-adjacent Adjacent channel Adjacent channel Non-adjacent
Channel centre
channel centre centre frequency centre frequency channel centre
frequency
frequency (wavelength) (wavelength) (wavelength) frequency
(wavelength)  (wavelength)
a
iox
a
ioc
Frequency (THz) for DWDM devices, wavelength (nm) for CWDM and WWDM devices

IEC  0077/14
Figure 9 – Illustration of non-adjacent channel isolation
3.3.21
mini
...