激光束功率、能量和时间特征的试验方法

BS EN ISO 11554:2008 ICS 31.260 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Optics and photonics — Lasers and laser- related equipment — Test methods for laser beam power, energy and temporal characteristics (ISO 11554:2006) This British Standard was published under the authority of the Standards Policy and Strategy Committee on © BSI 2009 ISBN 978 0 580 62193 2 Amendments/corrigenda issued since publication Date Comments BS EN ISO 11554:2008 National foreword This British Standard is the UK implementation of EN ISO 11554: 2008. It is identical to ISO 11554:2006. It supersedes BS EN ISO 11554:2006 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee CPW/172/9, Electro-optical systems. 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 contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. 2 ebruary 20098 F www.bzfxw.com EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 11554 July 2008 ICS 31.260 Supersedes EN ISO 11554:2006 English Version Optics and photonics - Lasers and laser-related equipment - Test methods for laser beam power, energy and temporal characteristics (ISO 11554:2006) Optique et photonique - Lasers et équipements associés aux lasers - Méthodes d'essai de la puissance et de l'énergie des faisceaux lasers et de leurs caractéristiques temporelles (ISO 11554:2006) Optik und Photonik - Laser und Laseranlagen - Prüfverfahren für Leistung, Energie und Kenngrößen des Zeitverhaltens von Laserstrahlen (ISO 11554:2006) This European Standard was approved by CEN on 22 June 2008. 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 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION C O M I T É E U R O P É E N D E N O R M A LI S A T I O N EUR OP ÄIS C HES KOM ITEE FÜR NOR M UNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2008 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11554:2008: E www.bzfxw.com BS EN ISO 11554:2008 BS EN ISO 11554:2008 EN ISO 11554:2008 (E) 4 Annex ZA ((informative) Relationship between this European Standard and the Essential Requirements of EU Directive 98/37/EC This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association to provide one means of conforming to Essential Requirements of the New Approach Directive for machinery 98/37/EC amended by Directive 98/79/EC. Once this standard is cited in the Official Journal of the European Communities under that Directive and has been implemented as a national standard in at least one Member State, compliance with the normative clauses of this standard confers, within the limits of the scope of this standard, a presumption of conformity with the corresponding Essential Requirements 1.5.10 Radiation and 1.5.12 Laser equipment of that Directive and associated EFTA regulations. WARNING: Other requirements and other EU Directives may be applicable to the products falling within the scope of this International standard. www.bzfxw.com BS EN ISO 11554:2008BS EN ISO 11554:2008 EN ISO 11554:2008 (E) 5 Annex ZB (informative) Relationship between this European Standard and the Essential Requirements of EU Directive 2006/42/EC This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association to provide a means of conforming to Essential Requirements of the New Approach Directive 2006/42/EC on machinery. Once this standard is cited in the Official Journal of the European Communities under that Directive and has been implemented as a national standard in at least one Member State, compliance with the normative clauses of this standard confers, within the limits of the scope of this standard, a presumption of conformity with the relevant Essential Requirements 1.5.10 Radiation and 1.5.12 Laser radiation of that Directive and associated EFTA regulations. WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling within the scope of this standard. www.bzfxw.com BS EN ISO 11554:2008 ISO 11554:2006(E) © ISO 2006 – All rights reserved iii Contents Page Foreword............................................................................................................................................................ iv Introduction ........................................................................................................................................................ v 1 Scope ..................................................................................................................................................... 1 2 Normative references ........................................................................................................................... 1 3 Terms and definitions........................................................................................................................... 1 4 Symbols and units of measurement ................................................................................................... 2 5 Measurement principles....................................................................................................................... 3 6 Measurement configuration, test equipment and auxiliary devices ............................................... 3 6.1 Preparation ............................................................................................................................................ 3 6.2 Control of environmental impacts ...................................................................................................... 6 6.3 Detectors ............................................................................................................................................... 6 6.4 Beam-forming optics ............................................................................................................................ 7 6.5 Optical attenuators ............................................................................................................................... 7 7 Measurements....................................................................................................................................... 7 7.1 General................................................................................................................................................... 7 7.2 Power of cw lasers................................................................................................................................ 7 7.3 Power stability of cw lasers................................................................................................................. 8 7.4 Pulse energy of pulsed lasers ............................................................................................................. 8 7.5 Energy stability of pulsed lasers......................................................................................................... 8 7.6 Temporal pulse shape, pulse duration, rise time, fall time and peak power.................................. 8 7.7 Pulse duration stability ........................................................................................................................ 8 7.8 Pulse repetition rate ............................................................................................................................. 8 7.9 Small signal cut-off frequency ............................................................................................................ 9 8 Evaluation.............................................................................................................................................. 9 8.1 General................................................................................................................................................... 9 8.2 Power of cw lasers................................................................................................................................ 9 8.3 Power stability of cw lasers............................................................................................................... 10 8.4 Pulse energy of pulsed lasers ........................................................................................................... 10 8.5 Energy stability of pulsed lasers....................................................................................................... 10 8.6 Temporal pulse shape, pulse duration, rise time, fall time and peak power................................ 10 8.7 Pulse duration stability ...................................................................................................................... 13 8.8 Pulse repetition rate ........................................................................................................................... 13 8.9 Small signal cut-off frequency .......................................................................................................... 13 9 Test Report .......................................................................................................................................... 13 Annex A (informative) Relative intensity noise (RIN) ................................................................................... 16 Bibliography ..................................................................................................................................................... 18 www.bzfxw.com BS EN ISO 11554:2008 ISO 11554:2006(E) iv © ISO 2006 – All rights reserved 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. 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 voting. 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 patent rights. ISO 11554 was prepared by Technical Committee ISO/TC 172, Optics and photonics, Subcommittee SC 9, Electro-optical systems. This third edition cancels and replaces the second edition (ISO 11554:2003), which has been technically revised. For the purposes of this International Standard, the CEN annex regarding fulfilment of European Council Directives has been removed. www.bzfxw.com BS EN ISO 11554:2008 ISO 11554:2006(E) © ISO 2006 – All rights reserved v Introduction The measurement of laser power (energy for pulsed lasers) is a common type of measurement performed by laser manufacturers and users. Power (energy) measurements are needed for laser safety classification, stability specifications, maximum laser output specifications, damage avoidance, specific application requirements, etc. This document provides guidance on performing laser power (energy) measurements as applied to stability characterization. The stability criteria are described for various temporal regions (e.g., short-term, medium-term and long-term) and provide methods to quantify these specifications. This International Standard also covers pulse measurements where detector response speed can be critically important when analysing pulse shape or peak power of short pulses. To standardize reporting of power (energy) measurement results, a report template is also included. This International Standard is a Type B standard as stated in ISO 12100-1. The provisions of this International standard may be supplemented or modified by a Type C standard. Note that for machines which are covered by the scope of a Type C standard and which have been designed and built according to the provisions of that standard, the provisions of that Type C standard take precedence over the provisions of this Type B standard. www.bzfxw.com BS EN ISO 11554:2008 www.bzfxw.com BS EN ISO 11554:2008 INTERNATIONAL STANDARD ISO 11554:2006(E) © ISO 2006 – All rights reserved 1 Optics and photonics — Lasers and laser-related equipment — Test methods for laser beam power, energy and temporal characteristics 1 Scope This International Standard specifies test methods for determining the power and energy of continuous-wave and pulsed laser beams, as well as their temporal characteristics of pulse shape, pulse duration and pulse repetition rate. Test and evaluation methods are also given for the power stability of cw-lasers, energy stability of pulsed lasers and pulse duration stability. The test methods given in this International Standard are used for the testing and characterization of lasers. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the last edition of the referenced document (including any amendments) applies. ISO 11145:2006, Optics and optical instruments — Lasers and laser-related equipment — Vocabulary and symbols IEC 61040:1990, Power and energy measuring detectors, instruments and equipment for laser radiation International vocabulary of basic and general terms in metrology (VIM). BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML, 2nd ed. 1993 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 11145, in the VIM and the following apply. 3.1 relative intensity noise RIN R( f ) single-sided spectral density of the power fluctuations normalized to the square of the average power as a function of the frequency f NOTE 1 The relative intensity noise R( f ) or RIN as defined above is explicitly spoken of as the “relative intensity noise spectral density”, but usually simply referred to as RIN. NOTE 2 For further details, see Annex A. 3.2 small signal cut-off frequency fc frequency at which the laser power output modulation drops to half the value obtained at low frequencies when applying small, constant input power modulation and increasing the frequency www.bzfxw.com BS EN ISO 11554:2008 ISO 11554:2006(E) 2 © ISO 2006 – All rights reserved 4 Symbols and units of measurement The symbols and units specified in ISO 11145 and in Table 1 are used in this International Standard. Table 1 — Symbols and units of measurement Symbol Unit Term f Hz Frequency fc Hz Small signal cut-off frequency [ f1, f2] Hz Frequency range for which the relative intensity noise R( f ) is given k 1 Coverage factor for the determination of uncertainty m 1 Reading m 1 Mean value of readings P W Power averaged over the sampling period P W Mean power, averaged over the measurement period at the operating conditions specified by the manufacturer ∆P 1 Relative power fluctuation to a 95 % confidence level for the appropriate sampling period [∆P (1 µs) and/or ∆P (1 ms) and/or ∆P (0,1 s) and/or ∆P (1 s)] Q J Mean pulse energy ∆Q 1 Relative pulse energy fluctuation to a 95 % confidence level R( f ) Hz−1 or dB/Hz Relative intensity noise, RIN S(t) 1 Detector signal s 1 Measured standard deviation T s Pulse repetition period t s Measurement period Urel 1 Expanded relative uncertainty corresponding to a 95 % confidence level (coverage factor k = 2) Urel(C) 1 Expanded relative uncertainty of calibration corresponding to a 95 % confidence level (coverage factor k = 2) τF s Fall time of laser pulse ∆τH 1 Relative pulse duration fluctuation with regard to τH to a 95 % confidence level τR s Rise time of laser pulse ∆τ10 1 Relative pulse duration fluctuation with regard to τ10 to a 95 % confidence level NOTE 1 For further details regarding 95 % confidence level see ISO 2602 [1]. NOTE 2 The expanded uncertainty is obtained by multiplying the standard uncertainty by a coverage factor k = 2. It is determined according to the Guide to the Expression of Uncertainty in Measurement [3]. In general, with this coverage factor, the value of the measurand lies with a probability of approximately 95 % within the interval defined by the expanded uncertainty. NOTE 3 R( f ) expressed in dB/Hz equals 10 lg R( f ) with R( f ) given in Hz−1. www.bzfxw.com BS EN ISO 11554:2008 ISO 11554:2006(E) © ISO 2006 – All rights reserved 3 5 Measurement principles The laser beam is directed on to the detector surface to produce a signal with amplitude proportional to the power or energy of the laser. The amplitude versus time is measured. Radiation emitted by sources with large divergence angles is collected by an integrating sphere. Beam forming and attenuation devices may be used when appropriate. The evaluation method depends on the parameter to be determined and is described in Clause 8. 6 Measurement configuration, test equipment and auxiliary devices 6.1 Preparation 6.1.1 Sources with small divergence angles The laser beam and the optical axis of the measuring system shall be coaxial. Select the diameter (cross-section) of the optical system such that it accommodates the entire cross-section of the laser beam and so that clipping or diffraction loss is smaller than 10 % of the intended measurement uncertainty. Arrange an optical axis so that it is coaxial with the laser beam to be measured. Suitable optical alignment devices are available for this purpose (e.g., aligning lasers or steering mirrors). Mount the attenuators or beam-forming optics such that the optical axis runs through the geometrical centres. Care should be exercised to avoid systematic errors. NOTE 1 Reflections, external ambient light, thermal radiation and air currents are all potential sources of errors. After the initial preparation is completed, make an evaluati