EN ISO 7944:2024
(Main)Optics and photonics - Reference wavelengths (ISO 7944:2024)
Optics and photonics - Reference wavelengths (ISO 7944:2024)
This document specifies reference wavelengths to be used for the characterization of optical materials, optical systems and instruments, and ophthalmic lenses. It defines the associated principal refractive indices and principal dispersions, as well as the Abbe numbers with regard to these reference wavelengths and principal dispersions.
Optik und Photonik - Bezugswellenlängen (ISO 7944:2024)
Dieses Dokument legt Bezugswellenlängen fest, die für die Charakterisierung von optischen Werkstoffen, optischen Systemen und Instrumenten sowie ophthalmischen Linsen zu verwenden sind. Es definiert die zugehörigen Hauptbrechzahlen und die Hauptdispersionen sowie die Abbe-Zahlen bezogen auf diese Bezugswellenlängen und die Hauptdispersionen.
Optique et photonique - Longueurs d'onde de référence (ISO 7944:2024)
Le présent document définit des longueurs d'onde de référence à utiliser pour la caractérisation des matériaux optiques, des systèmes et des instruments d'optique et des verres ophtalmiques. Il définit les indices de réfraction principaux et les dispersions principales associées, ainsi que les nombres d'Abbe par rapport à ces longueurs d'onde de référence et aux dispersions principales.
Optika in fotonska tehnologija - Referenčne valovne dolžine (ISO 7944:2024)
Ta dokument določa referenčne valovne dolžine za karakterizacijo optičnih materialov, optičnih sistemov in instrumentov ter optičnih leč. Opredeljuje povezane glavne lomne količnike in glavne disperzije ter Abbejeva števila za te referenčne valovne dolžine in glavne disperzije.
General Information
- Status
- Published
- Publication Date
- 03-Dec-2024
- Technical Committee
- CEN/TC 170 - Ophthalmic optics
- Drafting Committee
- CEN/TC 170 - Ophthalmic optics
- Current Stage
- 6060 - Definitive text made available (DAV) - Publishing
- Start Date
- 04-Dec-2024
- Completion Date
- 04-Dec-2024
Relations
- Effective Date
- 19-Jan-2023
- Effective Date
- 18-Jan-2023
Overview
EN ISO 7944:2024 (ISO 7944:2024) - titled Optics and photonics - Reference wavelengths - defines standardized reference wavelengths, associated principal refractive indices, principal dispersions, and Abbe numbers for characterizing optical materials, optical systems and instruments, and ophthalmic lenses. Endorsed by CEN in December 2024 and published as EN ISO 7944:2024, this third edition supersedes the 1998 version and updates wavelength tables and precision aligned to authoritative sources.
Key topics and technical requirements
- Reference wavelengths: Specifies commonly used lines, notably the mercury e-line 546.075 nm (default if nothing is specified) and the helium d-line 587.562 nm for ophthalmic and many non-ophthalmic uses.
- Principal refractive index and dispersion: Defines how to determine the principal refractive index at a reference line and how to calculate principal dispersion using refractive indices at specified spectral lines (F, C, F′, C′) for the chosen reference.
- Abbe number definitions: Provides formulas to compute Abbe numbers relative to the stated reference wavelengths and principal dispersions, enabling consistent chromatic dispersion characterization.
- Wavelength tables: Includes recommended wavelengths across the ultraviolet, visible, infrared, and laser spectral ranges (examples: Hg 546.075 nm, He 587.562 nm; additional Cd, H, He lines and common laser lines such as 632.816 nm and 1 064.1 nm).
- Traceability and data sources: Wavelength values and precision are aligned with recognized databases such as the NIST Atomic Spectra Database; vocabulary cross-references ISO 9802.
Applications and who should use it
EN ISO 7944:2024 is essential for professionals and organizations requiring consistent spectral references and dispersion metrics:
- Optical material manufacturers and glass suppliers for specification sheets
- Lens designers and ophthalmic laboratories for prescription and performance evaluation
- Optical system and instrument manufacturers for calibration and component selection
- Metrology and calibration laboratories ensuring traceable refractive index/dispersion reporting
- Photonics researchers and laser system integrators specifying or comparing wavelengths
Practical uses include calculating Abbe numbers for chromatic performance, selecting reference lines for refractometry, reporting material data, and unifying wavelength choices across procurement and test procedures.
Related standards and references
- ISO 9802 - Raw optical glass vocabulary (terminology for principal dispersion and Abbe number)
- NIST Atomic Spectra Database - primary source for spectral line data and wavelengths
- EN ISO 7944:2024 is the CEN-adopted European version of ISO 7944:2024
Keywords: EN ISO 7944:2024, reference wavelengths, optics and photonics, Abbe numbers, principal refractive index, principal dispersion, ophthalmic lenses, optical materials.
Frequently Asked Questions
EN ISO 7944:2024 is a standard published by the European Committee for Standardization (CEN). Its full title is "Optics and photonics - Reference wavelengths (ISO 7944:2024)". This standard covers: This document specifies reference wavelengths to be used for the characterization of optical materials, optical systems and instruments, and ophthalmic lenses. It defines the associated principal refractive indices and principal dispersions, as well as the Abbe numbers with regard to these reference wavelengths and principal dispersions.
This document specifies reference wavelengths to be used for the characterization of optical materials, optical systems and instruments, and ophthalmic lenses. It defines the associated principal refractive indices and principal dispersions, as well as the Abbe numbers with regard to these reference wavelengths and principal dispersions.
EN ISO 7944:2024 is classified under the following ICS (International Classification for Standards) categories: 11.040.70 - Ophthalmic equipment; 17.180.01 - Optics and optical measurements in general. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 7944:2024 has the following relationships with other standards: It is inter standard links to EN ISO 7944:1998, EN ISO 7944:1998/AC:2009. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase EN ISO 7944:2024 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of CEN standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-februar-2025
Nadomešča:
SIST EN ISO 7944:2000
SIST EN ISO 7944:2000/AC:2010
Optika in fotonska tehnologija - Referenčne valovne dolžine (ISO 7944:2024)
Optics and photonics - Reference wavelengths (ISO 7944:2024)
Optik und optische Instrumente - Bezugswellenlängen (ISO 7944:2024)
Optique et instruments d'optique - Longueurs d'onde de référence (ISO 7944:2024)
Ta slovenski standard je istoveten z: EN ISO 7944:2024
ICS:
11.040.70 Oftalmološka oprema Ophthalmic equipment
17.180.01 Optika in optična merjenja na Optics and optical
splošno measurements in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 7944
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2024
EUROPÄISCHE NORM
ICS 11.040.70; 17.180.01 Supersedes EN ISO 7944:1998
English Version
Optics and photonics - Reference wavelengths (ISO
7944:2024)
Optique et photonique - Longueurs d'onde de Optik und Photonik - Bezugswellenlängen (ISO
référence (ISO 7944:2024) 7944:2024)
This European Standard was approved by CEN on 1 December 2024.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7944:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 7944:2024) has been prepared by Technical Committee ISO/TC 172 "Optics and
photonics" in collaboration with Technical Committee CEN/TC 170 “Ophthalmic optics” the secretariat
of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2025, and conflicting national standards shall be
withdrawn at the latest by June 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 7944:1998.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 7944:2024 has been approved by CEN as EN ISO 7944:2024 without any modification.
International
Standard
ISO 7944
Third edition
Optics and photonics — Reference
2024-11
wavelengths
Optique et photonique — Longueurs d'onde de référence
Reference number
ISO 7944:2024(en) © ISO 2024
ISO 7944:2024(en)
© 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
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 7944:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Reference wavelengths, principal dispersions and Abbe numbers . 1
4.1 General .1
4.2 Mercury e-line 546,075 nm .1
4.3 Helium d-line 587,562 nm .2
4.4 Wavelength tables .2
Bibliography . 4
iii
SIST EN ISO 7944:2
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