ISO 8237:2024

Optics and photonics — Optical materials and components — Specification of chalcogenide glass used in the infrared spectrum

This document defines chalcogenide glass correctly from a chemical perspective and specifies basic characterization and reporting of optical properties of chalcogenide glass used in the infrared spectral range from 0,78 um to 25 um

Optique et photonique — Matériaux et composants optiques — Spécification des verres de chalcogénure utilisés dans le spectre infrarouge

General Information

• Status: Published
• Publication Date: 25-Jun-2024
• ICS: 37.020 - Optical equipment
• Technical Committee: ISO/TC 172/SC 3 - Optical materials and components
• Drafting Committee: ISO/TC 172/SC 3 - Optical materials and components
• Current Stage: 6060 - International Standard published
• Start Date: 26-Jun-2024
• Due Date: 23-Aug-2024
• Completion Date: 26-Jun-2024

Standards Content (Sample)

International
Standard
ISO 8237
First edition
Optics and photonics — Optical
2024-06
materials and components —
Specification of chalcogenide glass
used in the infrared spectrum
Optique et photonique — Matériaux et composants optiques —
Spécification des verres de chalcogénure utilisés dans le spectre
infrarouge
Reference number
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and units. 3
5 Optical properties . 3
5.1 General .3
5.2 Transmittance .4
5.3 Refractive index .4
5.4 Temperature dependence of the refractive index .4
5.5 Relative partial dispersion .4
6 Tolerances . 4
6.1 General .4
6.2 Refractive index variation .5
6.3 Optical homogeneity (homogeneity of refractive index dn ) .5
λ
6.4 Striae .5
6.5 Bubbles and inclusions .6
7 Data sheet contents . 6
Bibliography . 8

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 3,
Optical materials and components.
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
Introduction
This document applies to the specification of chalcogenide glass used in the infrared spectrum. Chalcogenide
glass described in this document is transparent in the infrared region.
Chalcogenide glass has a wide range of transparency from the visible to the infrared wavelength region. This
depends on chalcogenide chemical composition. The optical properties of chalcogenide glass can provide
flexibility and further capability for IR optical system.
Nowadays, chalcogenide glass is used as a substitute material for traditional infrared materials like
germanium, silicon or zinc selenide. The market for chalcogenide glasses is rapidly expanding. However, this
new material is sometimes distributed without specifying its properties and qualities, which can confuse
users. In consideration of the rapidly increasing of market for infrared application, the definition and
standardization of chalcogenide glass for infrared optics are necessary.

v
International Standard ISO 8237:2024(en)
Optics and photonics — Optical materials and components
— Specification of chalcogenide glass used in the infrared
spectrum
1 Scope
This document defines chalcogenide glass correctly from a chemical perspective and specifies basic
characterization and reporting of optical properties of chalcogenide glass used in the infrared spectral
range from 0,78 um to 25 um
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 12123:2018, Optics and photonics — Specification of raw optical glass
ISO 15368, Optics and photonics — Measurement of reflectance of plane surfaces and transmittance of plane
parallel elements
ISO 17328, Optics and photonics — Optical materials and components — Test method for refractive index of
infrared optical materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology 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
glass
inorganic product, usually obtained after melting, cooling and annealing without crystallization; including
the solid state glass before production and the glass strip obtained in production
[SOURCE: ISO 9802:2022, 3.2.1]
3.2
chalcogenide glass
glass (3.1) compound comprising of at least one chalcogen element (group 16 in the periodic table) with the
exception of oxygen
Note 1 to entry: The compositions used in chalcogenide glass are sulfur (S), selenium (Se) and tellurium (Te).
Chalcogenide glass is also sometimes called sulfide glass, selenium glass or telluride glass depending on the most
abundant composition.
Note 2 to entry: Polonium (Po) and livermorium (Lv) are not typically considered for chalcogenide compositions.

3.3
regular transmittance
ratio of the regularly transmitted part of the (whole) transmitted flux to the incident flux
[SOURCE: ISO 11382:2010, 3.1]
Note 1 to entry: Typical transmittance spectra of glass is shown in Figure 1.
Key
X wavelength, λ, in micrometre
Y transmittance, τ , in percent
r
1 transmittance spectra of sulfide glass
2 transmittance spectra of selenide glass
3 transmittance spectra of telluride glass
Figure 1 — Typical transmittance spectra of sulfide (S) glass, selenide (Se) glass and telluride (Te) glass
3.4
internal transmittance
ratio of the radiant flux to the incident radiant flux of a collimated beam that passes, at normal incidence,
through a plane parallel polished plate, excluding reflection losses at the surfaces
2 43 22 2
−−ρρ 14 +− ρρ ++ 46τρ −+ 41ρ
()
r
τ =
i
2ρτ
r
where
τ is regular transmittance;
r
τ is internal transmittance;
i
ρ is reflectance.
[SOURCE: ISO 12123:2018, 3.12]
3.5
optical homogeneity
gradual refractive index variation within a single piece of optical glass given by the difference between the
maximum and minimum values of the refractive index within the optical glass
[SOURCE: ISO 12123:2018, 3.16]
3.6
striae
short spatial range variation of refractive index in glass with typical spatial extent from below one millimetre
up to several millimetres
[SOURCE: ISO 12123:2018, 3.17]
3.7
bubble
gaseous void in the bulk optical material of generally circular cross section
Note 1 to entry: Bubbles and solid inclusions are treated the same in assessing the quality of optical glass.
[SOURCE: ISO 12123:2018, 3.19]
3.8
inclusion
localized bulk material imperfections
EXAMPLE Bubbles, striae knots, small stones, sand and crystals.
Note 1 to entry: These terms are also applicable in the given wavelength range.
[SOURCE: ISO 12123:2018, 3.18]
4 Symbols and units
For the purpose of this document, the following symbols and units apply.
λ wavelength, expressed in micrometres
n refractive index at wavelength λ
λ
P relative partial dispersion
τ spectral regular transmittance of the specimen
r
τ internal transmittance
i
5 Optical properties
5.1 General
As with general optical glass, the composition of chalcogenide glass determines its optical properties. In
addition to the measurement and reporting method of the basic properties of transmittance, refractive

index, and relative partial dispersion which are necessary to consider the use of chalcogenide glass in optical
systems, this section defines temperature dependence of the refractive index also.
5.2 Transmittance
+3
The transmittance shall be measured at 20 °C. The standard thicknesses of the specimens shall be
−1
(2 ± 0,1) mm, (5 ± 0,1) mm or (10 ± 0,2) mm. The transmittance shall be represented by a graph, with the
wavelength (or wave number) as the X-axis, and the transmittance as the Y-axis. Uncertainty (e.g. standard
uncertainty (±σ) or expanded uncertainty (±kσ) with k = 2) for the transmittance shall be provided by error
bars on the curves, or in a statement in the graph description.
The following shall be reported:
— thickness of the sample (in the case of multiple curves, with suit
...

FINAL DRAFT
International
Standard
ISO/FDIS 8237
ISO/TC 172/SC 3
Optics and photonics — Optical
Secretariat: JISC
materials and components —
Voting begins on:
Specification of chalcogenide glass
2024-04-08
used in the infrared spectrum
Voting terminates on:
2024-06-03
Optique et photonique — Matériaux et composants optiques —
Spécification des verres de chalcogénure utilisés dans le spectre
infrarouge
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
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
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.
Reference number
ISO/FDIS 8237:2024(en) © ISO 2024

FINAL DRAFT
ISO/FDIS 8237:2024(en)
International
Standard
ISO/FDIS 8237
ISO/TC 172/SC 3
Optics and photonics — Optical
Secretariat: JISC
materials and components —
Voting begins on:
Specification of chalcogenide glass
used in the infrared spectrum
Voting terminates on:
Optique et photonique — Matériaux et composants optiques —
Spécification des verres de chalcogénure utilisés dans le spectre
infrarouge
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.
© ISO 2024
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 8237:2024(en) © ISO 2024

ii
ISO/FDIS 8237:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and units. 3
5 Optical properties . 3
5.1 General .3
5.2 Transmittance .4
5.3 Refractive index .4
5.4 Temperature dependence of the refractive index .4
5.5 Relative partial dispersion .4
6 Tolerances . 4
6.1 General .4
6.2 Refractive index variation .5
6.3 Optical homogeneity (homogeneity of refractive index dn ) .5
λ
6.4 Striae .5
6.5 Bubbles and inclusions .6
7 Data sheet contents . 6
Bibliography . 8

iii
ISO/FDIS 8237:2024(en)
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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 www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 3,
Optical materials and components.
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/FDIS 8237:2024(en)
Introduction
This document applies to the specification of the chalcogenide glass used in the infrared spectrum. The
chalcogenide glass described in this document is transparent in the infrared region.
The chalcogenide glass has a wide range of transparency from the visible to the infrared wavelength region.
This depends on the chalcogenide chemical composition. The optical properties of chalcogenide glass can
provide flexibility and further capability for IR optical system.
Nowadays, the chalcogenide glass is used as a substitute material for traditional infrared materials like
germanium, silicon or zinc selenide. The market for chalcogenide glasses is rapidly expanding. However,
this new material is sometimes distributed without specifying its properties and qualities, which can
confuse users. In consideration of the rapid increasing of market for infrared application, the definition and
standardization of the chalcogenide glass for infrared optics are necessary.

v
FINAL DRAFT International Standard ISO/FDIS 8237:2024(en)
Optics and photonics — Optical materials and components
— Specification of chalcogenide glass used in the infrared
spectrum
1 Scope
This document defines the chalcogenide glass correctly from the perspective of chemical and specifies basic
optical characterization and reporting method of chalcogenide glass used in the infrared spectral range
from 0,78 μm to 25 μm.
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 12123:2018, Optics and photonics — Specification of raw optical glass
ISO 15368, Optics and photonics — Measurement of reflectance of plane surfaces and transmittance of plane
parallel elements
ISO 17328, Optics and photonics — Optical materials and components — Test method for refractive index of
infrared optical materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology 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
glass
inorganic product, usually obtained after melting, cooling and annealing without crystallization; including
the solid state glass before production and the glass strip obtained in production
[SOURCE: ISO 9802:2022, 3.2.1]
3.2
chalcogenide glass
glass (3.1) compound comprising of at least one chalcogen element (group 16 in the periodic table) with the
exception of oxygen
Note 1 to entry: The compositions used in chalcogenide glass are sulfur (S), selenium (Se) and tellurium (Te).
Chalcogenide glass is also sometimes called sulfide glass, selenium glass or telluride glass depending on the most
abundant composition.
Note 2 to entry: Polonium (Po) and livermorium (Lv) are not typically considered for chalcogenide compositions.

ISO/FDIS 8237:2024(en)
3.3
regular transmittance
ratio of the regularly transmitted part of the (whole) transmitted flux to the incident flux
[SOURCE: ISO 11382:2010, 3.1]
Note 1 to entry: Typical transmittance spectra of glass is shown in Figure 1.
Key
X wavelength in micrometre
Y transmittance in percent
1 transmittance spectra of sulfide glass
2 transmittance spectra of selenide glass
3 transmittance spectra of telluride glass
Figure 1 — Typical transmittance spectra of sulfide (S) glass, selenide (Se) glass and telluride (Te) glass
3.4
internal transmittance
ratio of the radiant flux to the incident radiant flux of a collimated beam that passes, at normal incidence,
through a plane parallel polished plate, excluding reflection losses at the surfaces
2 43 22 2
−−ρρ 14 +− ρρ ++ 46τρ −+ 41ρ
()
r
τ =
i
2ρτ
r
where
ISO/FDIS 8237:2024(en)
τ is regular transmittance;
r
τ is internal transmittance;
i
ρ is reflectance.
[SOURCE: ISO 12123:2018, 3.12]
3.5
optical homogeneity
gradual refractive index variation within a single piece of optical glass given by the difference between the
maximum and minimum values of the refractive index within the optical glass
[SOURCE: ISO 12123:2018, 3.16]
3.6
striae
short spatial range variation of refractive index in glass with typical spatial extent from below one millimetre
up to several millimetres
[SOURCE: ISO 12123:2018, 3.17]
3.7
bubble
gaseous void in the bulk optical material of generally circular cross section
Note 1 to entry: Bubbles and solid inclusions are treated the same in assessing the quality of optical glass.
[SOURCE: ISO 12123:2018, 3.19]
3.8
inclusion
localized bulk material imperfections
EXAMPLE Bubbles, striae knots, small stones, sand and cry
...

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ISO/FDIS 8237:2024(en)
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Secretariat: JISC .
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Date: 2024-03-08xx
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Optics and photonics — Optical materials and components —
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Specification of chalcogenide glass used in the infrared spectrum .
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Optique et photonique — Matériaux et composants optiqueoptiques — Spécification des verres de
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chalcogénure utiliséutilisés dans le spectre infrarouge
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St l D fi iti
ISO/FDIS 8237:2024(Een) Formatted: Font: 11 pt, Bold
Formatted: Font: 11 pt, Bold
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Formatted: HeaderCentered
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication Formatted: Right: 1.5 cm, Bottom: 1 cm, Gutter: 0 cm,
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, Header distance from edge: 1.27 cm, Footer distance
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO from edge: 0.5 cm
at the address below or ISO’s member body in the country of the requester.
Commented [eXtyles1]: The reference "ISO 2024" is to a
withdrawn standard
ISO copyright office
Formatted: Default Paragraph Font
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Formatted: Default Paragraph Font
Phone: + 41 22 749 01 11
Formatted: Adjust space between Latin and Asian text,
EmailE-mail: [e-mail]
Adjust space between Asian text and numbers
Website: www.iso.orgwww.iso.org
Published in Switzerland
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ii © ISO 2024 – All rights reserved
ii
ISO/FDIS 8237:2024(en)
Formatted: Font: 11 pt, Bold
Formatted: Font: Bold
Formatted: HeaderCentered, Left
Contents
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and units . 3
5 Optical properties . 4
5.1 General . 4
5.2 Transmittance . 4
5.3 Refractive index . 4
5.4 Temperature dependence of the refractive index . 4
5.5 Relative partial dispersion . 5
6 Tolerances . 5
6.1 General . 5
6.2 Refractive index variation . 5
6.3 Optical homogeneity (homogeneity of refractive index dn ) . 6
λ
6.4 Striae . 6
6.5 Bubbles and inclusions . 7
7 Data sheet contents . 7
Bibliography . 8

Foreword iv
Introduction v
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 Symbols and units 3
5 Optical properties 4
5.1 General 4
5.2 Transmittance 4
5.3 Refractive index 4
5.4 Temperature dependence of the refractive index 4
Formatted: Font: 10 pt
5.5 Relative partial dispersion 5
Formatted: Font: 10 pt
6 Tolerances 5
Formatted: Font: 10 pt
6.1 General 5
Formatted: FooterCentered, Left, Line spacing: single
6.2 Refractive index variation 5
Formatted: Font: 11 pt
6.3 Optical homogeneity (homogeneity of refractive index dn ) 5
λ
Formatted: FooterPageRomanNumber, Left, Space
After: 0 pt, Line spacing: single
© ISO 2024 – All rights reserved
iii
ISO/FDIS 8237:2024(Een) Formatted: Font: 11 pt, Bold
Formatted: Font: 11 pt, Bold
Formatted: Font: Bold
6.4 Striae 6
Formatted: HeaderCentered
6.5 Bubbles and inclusions6
7 Data sheet contents 7
Bibliography 8
Formatted: FooterPageRomanNumber
iv © ISO 2024 – All rights reserved
iv
ISO/FDIS 8237:2024(en)
Formatted: Font: 11 pt, Bold
Formatted: Font: Bold
Formatted: HeaderCentered, Left
Foreword
Formatted: Adjust space between Latin and Asian text,
Adjust space between Asian text and numbers
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 document 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).
Formatted: English (United Kingdom)
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such
patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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
www.iso.org/iso/foreword.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 3,
Optical materials and components.
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.htmlwww.iso.org/members.html.
Formatted: Font: 10 pt
Formatted: Font: 10 pt
Formatted: Font: 10 pt
Formatted: FooterCentered, Left, Line spacing: single
Formatted: Font: 11 pt
Formatted: FooterPageRomanNumber, Left, Space
After: 0 pt, Line spacing: single
© ISO 2024 – All rights reserved
v
ISO/FDIS 8237:2024(Een) Formatted: Font: 11 pt, Bold
Formatted: Font: 11 pt, Bold
Formatted: Font: Bold
Introduction
Formatted: HeaderCentered
This document applies to the specification of the chalcogenide glass used in the infrared spectrum. The
chalcogenide glass described in this document is transparent in the infrared region.
The chalcogenide glass has a wide range of transparency from the visible to the infrared wavelength region.
This depends on the chalcogenide chemical composition. The optical properties of chalcogenide glass can
provide flexibility and further capability for IR optical system.
Nowadays, the chalcogenide glass is used as a substitute material for traditional infrared materials like
germanium, silicon or zinc selenide. The market for chalcogenide glasses is rapidly expanding. However, this
new material is sometimes distributed without specifying its properties and qualities, which can confuse
users. In consideration of the rapid increasing of market for infrared application, the definition and
standardization of the chalcogenide glass for infrared optics are necessary.
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FINAL DRAFT International Standard ISO/FDIS 8237:2024(en)

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Optics and photonics — Optical materials and components —
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Specification of chalcogenide glass used in the infrared spectrum
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1 Scope
numbers
This document defines the chalcogenide glass correctly from the perspective of chemical and specifies basic
optical characterization and reporting method of chalcogenide glass used in the infrared spectral range from
0,78 μm to 25 μm.
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.
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ISO 12123:2018, Optics and photonics — Specification of raw optical glass Formatted: Default Paragraph Font
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ISO 12123:2018, Optics and photonics — Specification of raw optical glass
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ISO 15368, Optics and photonics — Measurement of reflectance of plane surfaces and transmittance of plane
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
parallel elements
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
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ISO 17328, Optics and photonics — Optical materials and components — Test method for refractive
index of infrared optical materials
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3 Terms and definitions
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For the purposes of this document, the following terms and definitions apply.
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https://www.iso.org/obp/ui. Please verify the URL.
— — ISO Online browsing platform: available at https://www.iso.org/obphttps://www.iso.org/obp
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— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
stops: Not at 0.7 cm + 1.4 cm + 2.1 cm + 2.8 cm +
3.5 cm + 4.2 cm + 4.9 cm + 5.6 cm + 6.3 cm + 7 cm
3.1
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glass
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inorganic product, usually obtained after melting, cooling and annealing without crystallization; including the
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