1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 21254-1:2011Lasers and laser-relatedequipment Test methodsfor laser-induced damagethresholdPart 1: Definitions and general principles(ISO 21254-1:2011)BS EN ISO 21254-1
2、:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO21254-1:2011. Together with BS EN ISO 21254-2:2011, it supersedesBS EN ISO 11254-1:2000 and BS EN ISO 11254-2:2001 which arewithdrawn.The UK participation in its preparation was entrusted to TechnicalCommi
3、ttee CPW/172/9, Electro-optical systems.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 52
4、998 6ICS 31.260Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2011.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROP
5、ENNE EUROPISCHE NORM EN ISO 21254-1 July 2011 ICS 31.260 Supersedes EN ISO 11254-1:2000, EN ISO 11254-2:2001English Version Lasers and laser-related equipment - Test methods for laser-induced damage threshold - Part 1: Definitions and general principles (ISO 21254-1:2011) Lasers et quipements associ
6、s aux lasers - Mthodes dessai du seuil dendommagement provoqu par laser - Partie 1: Dfinitions et principes de base (ISO 21254-1:2011) Laser und Laseranlagen - Prfverfahren fr die laserinduzierte Zerstrschwelle - Teil 1: Begriffe und allgemeine Grundstze (ISO 21254-1:2011) This European Standard was
7、 approved by CEN on 14 July 2011. 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 natio
8、nal 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 langua
9、ge 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, Latvi
10、a, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussel
11、s 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 21254-1:2011: EBS EN ISO 21254-1:2011EN ISO 21254-1:2011 (E) 3 Foreword This document (EN ISO 21254-1:2011) has been prepared by Technical Committee ISO/TC 172 “Optics and
12、photonics“ in collaboration with Technical Committee CEN/TC 123 “Lasers and photonics” 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 January 2012, and co
13、nflicting national standards shall be withdrawn at the latest by January 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This do
14、cument supersedes EN ISO 11254-1:2000, EN ISO 11254-2:2001. 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,
15、 Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 21254-1:2011 has been approved by CEN a
16、s a EN ISO 21254-1:2011 without any modification. BS EN ISO 21254-1:2011ISO 21254-1:2011(E) ISO 2011 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .2 4 Symbols and units of measurement3 5 Sampling.4 6 Test methods .4 6.1 Prin
17、ciple4 6.2 Apparatus.5 6.3 Preparation of specimens.10 6.4 Procedure.10 7 Accuracy.11 8 Test report11 Annex A (informative) Units and scaling of laser-induced damage thresholds.13 Bibliography14 BS EN ISO 21254-1:2011ISO 21254-1:2011(E) iv ISO 2011 All rights reservedForeword ISO (the International
18、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 esta
19、blished 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 standardiza
20、tion. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for votin
21、g. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. 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
22、patent rights. ISO 21254-1 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 9, Electro-optical systems. This first edition of ISO 21254-1:2011, together with ISO 21254-2:2011, cancels and replaces ISO 11254-1:2000 and ISO 11254-2:2001, which have been technically
23、 revised. ISO 21254 consists of the following parts, under the general title Lasers and laser-related equipment Test methods for laser-induced damage threshold: Part 1: Definitions and general principles Part 2: Threshold determination Part 3: Assurance of laser power (energy) handling capabilities
24、Part 4: Inspection, detection and measurement Technical Report BS EN ISO 21254-1:2011ISO 21254-1:2011(E) ISO 2011 All rights reserved vIntroduction Optical components can be damaged by laser irradiation of sufficiently high energy or power. At any specified laser irradiation level and operation mode
25、 of the laser source, the probability for laser damage is usually higher for the surface of a component than for the bulk. Thus, the limiting value of an optical component is frequently given by the damage threshold of its surface which might be coated to influence the optical properties. Bulk damag
26、e is observed if the electrical field strength in the bulk of the component is enhanced by self-focusing, interference, scattering or other effects. Also, imperfections, such as inclusions, dislocations, colour centres or inhomogeneities, can reduce the power-handling capability in the bulk of an op
27、tical component. Damage by single laser pulses is often induced by defects or mechanical stress in the coating, contamination of the surface, or optical absorption, leading to catastrophic heating of the surface. For multiple-pulse operation, not only reversible mechanisms induced by thermal heating
28、 and distortion but also irreversible damage mechanisms induced by ageing, microdamage, moisture damage and generation or migration of defects are observed. The various parts of this International Standard are concerned with the determination of irreversible damage of the optical surfaces and the bu
29、lk of an optical component under the influence of a laser beam. Depending on the environmental conditions, damage is a function of the material properties and the laser parameters, in particular wavelength, spot size and irradiation duration. This part of ISO 21254 is dedicated to the fundamentals a
30、nd general principles of the measurement of laser-induced damage thresholds (LIDTs). On the basis of the apparatus and measurement protocols described in ISO 21254-1, ISO 21254-2 and ISO 21254-3, this part of ISO 21254 outlines procedures for damage testing under different conditions. The protocols
31、for the determination of the 1-on-1 and S-on-1 damage thresholds are described in ISO 21254-2. The 1-on-1 test is a damage threshold measurement procedure that uses one shot of laser radiation on each unexposed site on the specimen surface. In contrast to this, the S-on-1 measurement programme is ba
32、sed on a series of pulses with constant energy density applied to each unexposed site of the specimen surface. This test reflects the operational conditions of the sample in typical applications but, compared to the 1-on-1 measurement protocol, the experimental effort necessary for S-on-1 tests is s
33、ignificantly higher. ISO 21254-3 concentrates on the assurance of the power or energy density handling capability of optical surfaces, leaving samples that pass the test undamaged. ISO/TR 21254-4, which considers damage detection methods and the inspection of tested surfaces, is a Technical Report w
34、hich complements ISO 21254-1. BS EN ISO 21254-1:2011BS EN ISO 21254-1:2011INTERNATIONAL STANDARD ISO 21254-1:2011(E) ISO 2011 All rights reserved 1Lasers and laser-related equipment Test methods for laser-induced damage threshold Part 1: Definitions and general principles WARNING The extrapolation o
35、f damage data can lead to an overestimation of the laser-induced damage threshold. In the case of toxic materials (e.g. ZnSe, GaAs, CdTe, ThF4, chalcogenides, Be, Cr, Ni), this can lead to serious health hazards. See Annex A for further comments. 1 Scope This part of ISO 21254 defines terms used in
36、conjunction with, and the general principles of, test methods for determining the laser-induced damage threshold and for the assurance of optical laser components subjected to laser radiation. 2 Normative references The following referenced documents are indispensable for the application of this doc
37、ument. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 10110-7, Optics and photonics Preparation of drawings for optical elements and systems Part 7: Surface imperfection tolerances IS
38、O 11145, Optics and photonics Lasers and laser-related equipment Vocabulary and symbols ISO 11146-1, Lasers and laser-related equipment Test methods for laser beam widths, divergence angles and beam propagation ratios Part 1: Stigmatic and simple astigmatic beams ISO 11146-2, Lasers and laser-relate
39、d equipment Test methods for laser beam widths, divergence angles and beam propagation ratios Part 2: General astigmatic beams ISO 21254-2, Lasers and laser-related equipment Test methods for laser-induced damage threshold Part 2: Threshold determination ISO 21254-3, Lasers and laser-related equipme
40、nt Test methods for laser-induced damage threshold Part 3: Assurance of laser power (energy) handling capabilities ISO/TR 21254-4, Lasers and laser-related equipment Test methods for laser-induced damage threshold Part 4: Inspection, detection and measurement BS EN ISO 21254-1:2011ISO 21254-1:2011(E
41、) 2 ISO 2011 All rights reserved3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 11145 and the following apply. 3.1 surface damage any permanent laser-radiation-induced change in the characteristics of the surface of the specimen which can be observed
42、 by an inspection technique and at a sensitivity related to the intended operation of the product concerned NOTE Damage may occur on the front surface or the rear surface of the optical component. The damage threshold value for the front surface may differ from that for the rear surface. 3.2 bulk da
43、mage any permanent laser-radiation-induced change in the characteristics of the bulk of the specimen which can be observed by an inspection technique and at a sensitivity related to the intended operation of the product concerned 3.3 1-on-1 test test programme that uses one shot of laser radiation o
44、n each unexposed site on the specimen surface 3.4 linear power density Fthlinear power density threshold, expressed in watts per centimetre (W/cm), above which damage might occur NOTE The linear power density is applicable for cw and long-pulse operation. For laser damage considerations, a long puls
45、e is assumed when the thermal transit distance (2Deff)1/2, where D is the thermal diffusivity, is of the same order of size as the test spot diameter dT,eff. 3.5 S-on-1 test test programme that uses a series of pulses with constant energy density on each unexposed site with a short and constant time
46、 interval between two successive pulses, where the length of the time interval between the pulses of a series is given by the reciprocal of the pulse repetition rate of the laser source 3.6 number of shots per interrogation site S number of pulses in a pulse train used in an S-on-1 test 3.7 threshol
47、d highest quantity of laser radiation incident upon the optical component for which the extrapolated probability of damage is zero, where the quantity of laser radiation may be expressed as energy density Hth, power density Eth, or linear power density Fth3.8 target plane plane tangential to the sur
48、face of the specimen at the point of intersection of the test laser beam axis with the surface of the specimen 3.9 effective area AT,effratio of pulse energy to maximum energy density of the laser pulse in the target plane NOTE For spatial beam profiling perpendicular to the direction of beam propag
49、ation and for angles of incidence differing from 0 rad, the cosine of the angle of incidence is included in the calculation of the effective area. BS EN ISO 21254-1:2011ISO 21254-1:2011(E) ISO 2011 All rights reserved 33.10 effective beam diameter dT,effdouble the square root of the effective area divided by : T,effT,eff2Ad =(1) 3.11 effective pulse duration effratio of pulse energy to peak pulse power of the pulse 3.12 typical pulse pulse with temporal and spatial shapes that represent the averag
