1、Optics and photonics Test methods for surface imperfections of optical elementsBS ISO 14997:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National forewordThis British Standard is the UK implementation of ISO 14997:2017. It supersedes BS ISO 14997:2011 , which
2、is withdrawn.The UK participation in its preparation was entrusted to Technical Committee CPW/172, Optics and Photonics.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a con
3、tract. Users are responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 88948 6ICS 37.020Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the auth
4、ority of the Standards Policy and Strategy Committee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 14997:2017 ISO 2017Optics and photonics Test methods for surface imperfections of optical elementsOptique et photonique Mthodes dessai appl
5、icables aux imperfections de surface des lments optiquesINTERNATIONAL STANDARDISO14997Third edition2017-08-31Reference numberISO 14997:2017(E)BS ISO 14997:2017ISO 14997:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless ot
6、herwise specified, 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 addres
7、s below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 14997:2017ISO 14997:2017(E)Foreword ivIntroduction v1 Scope . 12 Normative referenc
8、es 13 Terms and definitions . 14 Symbols 25 Inspection methods and levels 26 General information regarding visual inspection . 37 Evaluation methods for the visibility based specification of surface imperfections 37.1 Visual evaluation (IVV) . 37.1.1 General 37.1.2 Typical visual evaluation method .
9、 37.2 Visibility comparison inspection (ISV) . 47.2.1 General 47.2.2 Typical transmitted light visibility comparison method . 47.2.3 Alternative transmitted light visibility comparison method . 47.2.4 Reflective light visibility comparison method 58 Evaluation methods for the dimensional based speci
10、fication of surface imperfections 58.1 Visual evaluation (IVD) . 58.1.1 General 58.1.2 Typical visual evaluation method . 58.2 Dimensional comparison inspection (ISD) . 58.2.1 General 58.2.2 Typical dimensional comparison inspection method 68.3 Dimensional comparison inspection with magnification (I
11、MD) 68.3.1 General 68.3.2 Typical stereo microscope evaluation method 69 Test report . 7Annex A (normative) Visual inspection equipment 9Annex B (informative) Recommended dimensions of artefacts on a dimensional comparison standard 12Annex C (informative) Number of allowed smaller imperfections with
12、 equivalent area of the specified grade 13Bibliography .14 ISO 2017 All rights reserved iiiContents PageBS ISO 14997:2017ISO 14997:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing
13、 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 liais
14、on 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 Direc
15、tives, 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 som
16、e 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 declara
17、tions 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 asse
18、ssment, as well as information about ISOs 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 1, Fu
19、ndamental standards.This third edition cancels and replaces the second edition (ISO 14997:2011 ), which has been technically revised to adapt ISO 14997 to the new version of ISO 10110-7 . The main change compared to the previous edition is as follows: the addition of language required to accommodate
20、 visibility inspection.iv ISO 2017 All rights reservedBS ISO 14997:2017ISO 14997:2017(E)IntroductionStandard practice in the optics industry since the 1950s has been to visually inspect optical surfaces for small, localized imperfections and determine if they are acceptable.This document was develop
21、ed in response to worldwide demand for the standardization of test methods for surface imperfections. Surface imperfections, such as digs and scratches, arise from localized damage during or after manufacture. They can be visible as a result of the light they scatter, giving rise to a false impressi
22、on of poor quality. Alternatively, this light can appear as unwanted veiling glare (stray radiation) in an image plane, or it can lead to degradation in signal quality at an image sensor. Imperfections can also provide centres of stress, eventually leading to failure of components exposed to high la
23、ser radiation power/energy densities. In most cases, however, surface imperfections are representative of the quality of workmanship and do not have any impact whatsoever on the performance of the component in question.Since modern methods of surface examination are capable of atomic resolution, no
24、surface is likely to be found totally free of localized imperfections. Most surfaces produced are satisfactory for their intended purpose, but a small proportion can have suffered obvious damage and will be reworked or regarded as unacceptable. This can leave some components that, although slightly
25、damaged, can still be found acceptable, when tested, depending on the level of acceptability of surface imperfections requested by the customer and specified on drawings in ISO 101107 . This document describes how these methods are implemented.In some cases, it is necessary to measure or estimate th
26、e size of the imperfections on an optical surface. In other cases, however, it is necessary or desirable to assess their brightness or appearance, and not their size. In these cases, visual inspection is preferred over dimensional measurements.This document describes the human evaluation of surface
27、imperfections for the dimensional and visibility methods. New developments open the route to machine vision approaches which are more objective and exhibit an increased reproducibility, less conflict and an optimized production closer to the allowed specification, lowering cost10,11. Some of these m
28、achine vision-based approaches may be able to validate the surface imperfection specifications of ISO 101107 . It is incumbent upon the manufacturers and users of objective measurement equipment to demonstrate compatibility with the methods described herein and to report their results consistent wit
29、h the notation described in ISO 10110-7 .It should be noted that other light scattering imperfections, which also need to be measured, can arise as digs distributed over the surface of an incompletely polished surface, and as bubbles and as striae within an optical material. The measurement of laser
30、 damage thresholds also requires sensitive means for quantifying the level of radiation scattered by damage in its early stages. ISO 2017 All rights reserved vBS ISO 14997:2017This page deliberately left blankOptics and photonics Test methods for surface imperfections of optical elements1 ScopeThis
31、document specifies the physical principles and practical means for the implementation of methods for evaluating surface imperfections.For imperfections specified using the visibility method, two inspection methods are described. The first is visual evaluation of the surface without any comparison st
32、andard (IVV). The second is a visibility assessment of a surface imperfection when compared to an artefact of known brightness (ISV).For imperfections specified using the dimensional method, three methods are described. The first is visual evaluation of the surface without any comparison standard (I
33、VD). The second is a dimensional assessment of a surface imperfection when compared to an artefact of known size (ISD). The third is the dimensional measurement of a surface imperfection using magnification and either a comparison artefact of known size or a reticle or ruler (IMD).Instruments exist
34、that allow objective measurement of brightness (digital scatterometry) or size (digital microscopy). While these instruments can be used for evaluation of surface imperfections, they are beyond the scope of this document.This document applies to optical surfaces of components or assemblies such as d
35、oublets or triplets.This document can be applied to optical plastic components; however, attention is drawn to the fact that impact damage to plastic materials often looks very different from that on harder materials as it does not always result in the removal of material but instead can displace ma
36、terial, causing ripples in the surface. Consequently, visual comparisons of scratch and dig damage to plastic with those on glass or crystalline materials can give very different results.2 Normative referencesThe following documents are referred to in the text in such a way that some or all of their
37、 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 9211-1 , Optics and photonics Optical coatings Part 1: DefinitionsISO 10110-7 , Optic
38、s and photonics Preparation of drawings for optical elements and systems Part 7: Surface imperfectionsISO 11145 , Optics and photonics Lasers and laser-related equipment Vocabulary and symbols3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 101107 , IS
39、O 92111 and ISO 11145 and the following apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp INTERNATIONAL STANDARD ISO 14
40、997:2017(E) ISO 2017 All rights reserved 1BS ISO 14997:2017ISO 14997:2017(E)3.1brightness comparison standardplate, paddle, or window with one or more artefacts of known brightness grade3.2dimensional comparison standardplate, paddle, or window with one or more patterned artefacts (chrome on glass,
41、ink on film, iron oxide on glass, etched glass, focused ion beam milling (FIB) on glass substrate, etc.) of a specified size grade4 SymbolsIVVvisual inspection of visibilityISVsubjective comparison inspection of visibilityIVDvisual inspection of dimensionsISDsubjective comparison inspection of dimen
42、sionsIMDinspection with magnification of dimensions5 Inspection methods and levelsSurface imperfections may be specified and graded using the notations provided in ISO 101107 in terms of visibility or size. Surface imperfections may be evaluated visually with or without magnification, or objectively
43、 using equipment designed for the purpose. Table 1 shows the evaluation arrangements by inspection level for visibility of surface imperfections. Table 2 shows the evaluation arrangements by inspection level for dimensional specifications of surface imperfections.Table 1 Evaluation methods for the v
44、isibility based specification of surface imperfectionsInspection level Evaluation arrangement Comparison standardVisual evaluation (Level IVV) Any arrangement is allowed per 7.1None requiredVisibility comparison inspection (Level ISV)Any Annex A arrangement per 7.2 Brightness comparison standard ind
45、icated on the drawingIf no inspection level is indicated on the drawing, the default inspection level for visibility based specifications is ISV.Table 2 Evaluation methods for the dimensional based specification of surface imperfectionsInspection level Evaluation arrangement Comparison standardVisua
46、l evaluation (Level IVD) Any arrangement is allowed per 8.1None requiredDimensional comparison inspection (Level ISD)Figure A.3 arrangement per 8.2 Dimensional comparison standard per Annex BDimensional comparison inspection with magnification (Level IMD)Loupe or stereo microscope per 8.3Dimensional
47、 comparison standard per Annex BThe number of allowed smaller imperfections with equivalent area of the specified grade can be found in Annex C.The angular resolution of the human eye is about 1 arcminute9; therefore, an unstressed human inspector can reasonably estimate the size of imperfections la
48、rger than 0,1 grade under the arrangement described in Annex A. Assuming long imperfections can be resolved to approximately one-fourth of this value, a scratch of width 0,025 mm can be estimated under the same conditions. Since in accordance 2 ISO 2017 All rights reservedBS ISO 14997:2017ISO 14997:
49、2017(E)with ISO 101107 , imperfections shall be accumulated down to 0,16 the specification (or 0,25 for long imperfection), the default inspection method for specifications of 5/1 0,63; C1 0,63; L1 0,1 or larger shall be ISD. For smaller specifications, the default inspection level is IMD.When using the IMDmethod, the magnification and device resolution shall correlate with the required specification.EXAMPLE 1 For testing 5/1 0,04, the smallest imperfection size to test is 0,006 3 mm and therefore the magnif
