ISO/FDIS 11807-1

Integrated optics -- Vocabulary

Optique intégrée -- Vocabulaire

General Information

• Status: Published
• ICS: 01.040.31 - Electronics (Vocabularies)
• ICS: 31.260 - Optoelectronics. Laser equipment
• Technical Committee: ISO/TC 172/SC 9 - Laser and electro-optical systems
• Drafting Committee: ISO/TC 172/SC 9/WG 7 - Electro-optical systems other than lasers
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 14-Jul-2021
• Completion Date: 14-Jul-2021

Standards Content (sample)

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 11807-1
ISO/TC 172/SC 9
Integrated optics — Vocabulary —
Secretariat: DIN
Voting begins on:
Part 1:
2021-07-14
Optical waveguide basic terms and
Voting terminates on:
symbols
2021-09-08
Optique intégrée — Vocabulaire —
Partie 1: Termes fondamentaux et symboles des guides d'onde optique
ISO/CEN PARALLEL PROCESSING
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 11807-1:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. ISO 2021
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ISO/FDIS 11807-1:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

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ii © ISO 2021 – All rights reserved
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ISO/FDIS 11807-1:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

3.1 General ........................................................................................................................................................................................................... 1

3.2 Waveguide structures ....................................................................................................................................................................... 2

3.3 Modes in integrated optical waveguides .......................................................................................................................... 2

3.4 Refractive index distribution in integrated optical waveguides ................................................................... 4

3.5 Properties of integrated optical waveguides ................................................................................................................ 8

3.6 Loss or attenuation in integrated optical waveguides .......................................................................................... 8

Annex A (informative) Coordinate system ...................................................................................................................................................12

Annex B (informative) Symbols and units ....................................................................................................................................................13

Bibliography .............................................................................................................................................................................................................................14

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ISO/FDIS 11807-1:2021(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 172 Optics and photonics, Subcommittee

SC 9, Laser and electro optical systems, in collaboration with the European Committee for Standardization

(CEN) Technical Committee CEN/TC 123, Lasers and photonics, in accordance with the agreement on

technical cooperation between ISO and CEN (Vienna Agreement).

This second edition cancels and replaces the first edition (ISO 11807-1:2001), which has been technically

revised. The main changes compared to the previous edition are as follows:

— Terminologies that have not been frequently used over the last 5 to 10 years are revised to those

matching to current trends.

— In the revision process, terminologies and definitions are compared to similar terminology

definitions in IEC and harmonized.
A list of all parts of ISO 11807 can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html .
iv © ISO 2021 – All rights reserved
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ISO/FDIS 11807-1:2021(E)
Introduction

The aim of this document is to clarify the terms of the field of “integrated optics” and to define a unified

vocabulary. It is expected that this document will be revised periodically to adopt the requirements of

customers and suppliers of integrated optical products. At a later stage, it is planned to add definitions

from other International Standards which deal with integrated optics.

Some of the definitions are closely related to definitions given in IEC 60050-731. Wherever this can lead

to misunderstanding, integrated optics or integrated optical waveguide should be used together with

the defined term.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 11807-1:2021(E)
Integrated optics — Vocabulary —
Part 1:
Optical waveguide basic terms and symbols
1 Scope

This document defines basic terms for integrated optical devices, their related optical chips and optical

elements which find applications, for example, in the fields of optical communications and sensors.

— The coordinate system used in Clause 3 is described in Annex A.
— The symbols and units defined in detail in Clause 3 are listed in Annex B.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 11807-2, Integrated optics -- Vocabulary -- Part 2: Terms used in classification

ISO 14881, Integrated optics -- Interfaces -- Parameters relevant to coupling properties

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 11807-2 and ISO 14881 and

the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General
3.1.1
integrated optics

planar optical waveguide (3.2.1) structures, manufactured either in or on a substrate (3.2.6), including

the optical components necessary for the input and output coupling of lightwaves

Note 1 to entry: In this context the term “planar” is used to include small deviations from planarity which are

associated with Luneburg lenses, for example. By use of a suitable material, it is possible to integrate both

optoelectronic and purely optical functions on the same substrate. The simplest case is electrodes, which can

be used for controlling the properties of a waveguide. It is also possible to fabricate lasers and detectors using

compound semiconductor materials.

Note 2 to entry: It is envisaged that integrated optical components will be combined with other microtechnologies,

such as microelectronics and micromechanics, to build more complex systems. However, such systems are

beyond the scope of this part of ISO 11807, which will be concerned only with the integrated optical component

and its immediate interfaces (see IEC 60050-731:1991, 06-43).
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ISO/FDIS 11807-1:2021(E)
3.2 Waveguide structures
3.2.1
waveguide

transmission line designed to guide optical power consisting of structures which guide lightwaves on

the basis of a higher refractive index in the core (3.2.4) and a lower refractive index in the surrounding

material
Note 1 to entry: The lightwaves in a waveguide propagate in modes.
3.2.2
slab waveguide

waveguide (3.2.1) which confines the optical field between two light guiding parallel surfaces

Note 1 to entry: See Figure A.1 where the Cartesian coordinate system is indicated for defining the several

terminologies relating to waveguides.

Note 2 to entry: In the previous edition "planar waveguide" was used as a synonym.

3.2.3
strip waveguide
channel waveguide

waveguide (3.2.1) which confines the optical field in a two-dimensional cross-sectional area

perpendicular to the lightwave propagating direction (wave vector) along a one-dimensional path

3.2.4
core

region(s) of an integrated optical waveguide (3.2.1), in which the optical power is mainly confined

3.2.5
cladding
material surrounding the waveguide (3.2.1) core (3.2.4)

Note 1 to entry: In contrast to optical fibres for integrated optical waveguides, the cladding often consists of

more than one material. Normally, it is necessary to distinguish between lower cladding and upper cladding due

to the planar fabrication process of integrated optical waveguides.
3.2.6
substrate

carrier onto or within which the integrated optical waveguide (3.2.1) is fabricated

3.2.7
superstrate

cladding (3.2.5) medium or layer structure with which the core (3.2.4) of the integrated optical

waveguide (3.2.1) is covered

Note 1 to entry: An electrode, for example, should not be considered as a superstrate. Although it covers the

waveguide, it does not influence the optical properties of the waveguide due to an optically insulating layer of

sufficient thickness.
3.3 Modes in integrated optical waveguides
3.3.1
mode

eigenfunction of Maxwell's equations, representing an electromagnetic field in a certain space domain

and belonging to a family of independent solutions defined by specific boundary conditions

Note 1 to entry: Each mode is defined according to its order in the vertical and horizontal directions and its

polarization, the latter being separated into TE- and TM-modes. The mode order is given by indexing TE and

TM , where TE and TM represent the y- and x-direction of polarization, respectively. The symbols, i and j define

the mode indices (the order) along x (horizontal) and y (vertical) respectively.
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ISO/FDIS 11807-1:2021(E)
3.3.2
guided mode

electromagnetic wave whose electric field decays monotonically in the transverse direction everywhere

outside the core (3.2.4) and which does not lose power
3.3.3
TE mode

transverse electromagnetic wave, where the electric field vector is normal to the direction of

propagation; i.e., the electric field vector lies in the transverse plane (xy-plane).

Note 1 to entry: Strictly speaking, in strip waveguides, hybrid modes having a non-zero component of the electric

and magnetic field in the direction of propagation do exist. Pure TE- and TM-modes are only found in waveguides

with a corresponding geometry — for example in slab waveguides. For integrated optical waveguides in planar

substrates, the polarization state is usually defined relative to the substrate surface. In planar waveguides, the

electric field vector of TE modes lies in the y direction, as a result of the choice of the coordinate system.

3.3.4
TM mode

transverse electromagnetic wave, where the magnetic field vector is normal to the direction of

propagation; i.e., the magnetic field vector lies in the transverse plane (xy-plane).

Note 1 to entry: In planar waveguides, the magnetic field vector of TM mode lies in the y direction, as a result of

the choice of the coordinate system.
3.3.5
evanescent field

time varying electromagnetic field in an integrated optical waveguide (3.2.1) whose field amplitude

decays very rapidly and monotonically in the transverse direction outside the core (3.2.4), but without

an accompanying phase shift
3.3.6
leaky mode

mode (3.3.1) having an evanescent field (3.3.5) in the transverse direction outside the core (3.2.4) for a

finite distance but with an oscillating field in the transverse direction beyond that distance

Note 1 to entry: A leaky mode is attenuated due to radiation losses along the waveguide.

3.3.7
radiation mode

mode (3.3.1) which transfers power in the transverse direction everywhere external to the core (3.2.4)

3.3.8
single-mode waveguide
waveguide (3.2.1) which supports only one guided mode (3.3.2)

Note 1 to entry: The waveguide mode may consist of two orthogonal states of polarization.

3.3.9
multimode waveguide
waveguide (3.2.1) which supports more than one guided mode (3.3.2)
3.3.10
waveguide cutoff

transition of propagation mode (3.3.1) from being guided to being leaky or radiative

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ISO/FDIS 11807-1:2021(E)
3.3.11
cutoff wavelength
vacuum wavelength above which a given mode (3.3.1) is cutoff

Note 1 to entry: Due to the generally short length of integrated optical waveguides, the measured value strongly

depends on the waveguide structure. Therefore, special waveguide structures have to be fabricated to measure

the cutoff wavelength. The measurement methods known for optical fibres cannot be applied to integrated

optical waveguides.

Note 2 to entry: In fibre optics, the term cutoff wavelength is used to describe the cutoff wavelength of the second-

order mode. The reason is that the fundamental mode of a symmetrical dielectric waveguide has no cutoff and

the cutoff wavelength of the second order mode determines the single mode condition.

3.3.12
effective refractive index
DEPRECATED: equivalent refractive index
eff

ratio of the speed of light in vacuum to the phase velocity of the guided mode (3.3.2)

Note 1 to entry: The effective refractive index is determined by the waveguide dimensions and the refractive

index profile of the waveguide, including the medium adjacent to the core of the waveguide and the wavelength.

Each mode capable to propagate is characterized by its individual effective or equivalent refractive

...