1、BSI Standards PublicationBS ISO 17328:2014Optics and photonics Opticalmaterials and components Test method for refractiveindex of infrared opticalmaterialsBS ISO 17328:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 17328:2014. The UK participation in its
2、preparation was entrusted to TechnicalCommittee 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 contract. Users are responsible for its corre
3、ct application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 76435 6 ICS 37.020 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strateg
4、y Committee on 31 October 2014.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e d ISO 2014Optics and photonics Optical materials and components Test method for refractive index of infrared optical materialsOptique et photonique Matriaux et composants optiques Mthode dessai de
5、 lindice de rfraction des matriaux optiques infrarougesINTERNATIONAL STANDARDISO 17328First edition 2014-10-15Reference number ISO 17328:2014(E)BS ISO 17328:2014ISO 17328:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no pa
6、rt 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 ISOs member b
7、ody in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 17328:2014ISO 17328:2014(E)Contents PageForeword ivIntroduction v1 Scope . 12 Normative references
8、13 Terms and definitions . 14 Method for measuring 14.1 General . 14.2 Principle 24.3 Apparatus and procedure for measurement . 34.4 Wavelength of light beam for measurement . 35 Specimens 45.1 The shape and dimensions of the specimen prism . 45.2 Surface accuracy 46 Test report . 4Annex A (informat
9、ive) Apparatus for measurement . 6Annex B (informative) Analysis of errors .13Bibliography .15 ISO ISO pub-date year All rights reserved iiiBS ISO 17328:2014ISO 17328:2014(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO m
10、ember 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, governm
11、ental 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 maintenanc
12、e are described in the ISO/IEC Directives, 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
13、 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. Details of any patent rights identified during the development of the document will be in the Introduction and
14、/or on the ISO list of patent declarations 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 meaning of ISO specific terms and expressions related to conformity a
15、ssessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 172, Optics and photonics, Subcommittee SC 3, Optical materials and c
16、omponents.iv ISO ISO pub-date year All rights reservedBS ISO 17328:2014ISO 17328:2014(E)IntroductionThis International Standard applies to the measurement of relative refractive index to the air for infrared optical materials.Two major methods for measuring the refractive index of infrared materials
17、 exist. These are interferometric methods and minimum deviation methods. In this International Standard, a test method using minimum deviation for infrared materials is described, which is also used in the visible spectral range. It has the advantages of being applicable to more kinds of materials c
18、ompared with interferometric methods and of ease of data processing because of the simple measurement principle. ISO ISO pub-date year All rights reserved vBS ISO 17328:2014BS ISO 17328:2014Optics and photonics Optical materials and components Test method for refractive index of infrared optical mat
19、erials1 ScopeThis International Standard provides a standard method for measuring the relative refractive index to the air of infrared materials used in the infrared spectral range from 0,78 m to 25 m.The scope of this International Standard excludes methods for measuring the refractive index of bir
20、efringent materials and methods for measuring the complex refractive index.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated refe
21、rences, the latest edition of the referenced document (including any amendments) applies.ISO 11382:2010, Optics and photonics Optical materials and components Characterization of optical materials used in the infrared spectral range from 0,78 m to 25 m3 Terms and definitionsFor the purposes of this
22、document, the following terms and definitions apply.3.1refractive indexabsolute refractive indexratio of the velocity of the electromagnetic waves at a specific wavelength in a vacuum to the velocity of the waves in the materialSOURCE: ISO 12123:2010, 3.13.2relative refractive indexratio of the (abs
23、olute) refractive index of the material of the specimen to the (absolute) refractive index of the material in contact with the specimen at a specific wavelength3.3angle of minimum deviationangle between the ray incident upon the specimen prism and the ray exiting the specimen prism at its minimum va
24、lue, which occurs when the ray inside the specimen prism makes equal angles with the entrance and exit faces of the specimen prism4 Method for measuring4.1 GeneralIn this International Standard, the technique of the minimum deviation method for measuring refractive index is described.The minimum dev
25、iation method shall be applied for measuring refractive index.INTERNATIONAL STANDARD ISO 17328:2014(E) ISO 2014 All rights reserved 1BS ISO 17328:2014ISO 17328:2014(E)4.2 PrincipleAs shown in Figure 1, when the monochromatic light beam is refracted by the specimen prism with minimum deviation, the r
26、elative refractive index of the specimen prism to the air at the wavelength of the monochromatic light beam is described by Formula (1):nrel=+()()sin/sin/22(1)wherenrelis the relative refractive index of the specimen prism to the air; is the apex angle of the specimen prism; is the angle of minimum
27、deviation of the monochromatic light beam refracted by the specimen prism.MLOGMSPRSDOKeyMLO monochromatic light source opticsSP specimen prismRS rotating stageGM goniometerDO detector optics angle of minimum deviation apex angle of the specimen prismFigure 1 Schematic of the minimum deviation method
28、The monochromatic light beam shall be parallel to the plane of section, PS, of the specimen prism. (See Figure 2.)2 ISO 2014 All rights reservedBS ISO 17328:2014ISO 17328:2014(E)RLPSKeyRL ridge linePS plane of sectionFigure 2 Ridge line and the plane of section of the specimen prism4.3 Apparatus and
29、 procedure for measurementThe apparatus for measurement shall be equipped with the following:a) a method to emit a collimated monochromatic light beam of specified wavelength to the specimen prism;b) a method to vary the angle of the collimated monochromatic light beam to the entrance face of the sp
30、ecimen prism;c) a method to determine the direction of the monochromatic light beam refracted by the specimen prism;d) a method to indicate the angle of minimum deviation ;e) a method to measure the temperature of the specimen prism.Examples of apparatus for measurement of the angle of minimum devia
31、tion are shown in Annex A. A procedure for measurement is also described in Annex A. In addition, the absolute value of the angle of deviation error is described in Annex B.NOTE See Figure 1.4.4 Wavelength of light beam for measurementThe wavelengths of measurement shall adequately sample the spectr
32、al range of interest to enable curve fitting of the data to a dispersion formula, allowing calculation of the relative refractive index at any arbitrary wavelength within the spectral range. ISO 2014 All rights reserved 3BS ISO 17328:2014ISO 17328:2014(E)5 Specimens5.1 The shape and dimensions of th
33、e specimen prismThe specimen shall be a wedged prism made of the material to be measured. The entrance face and the exit face shall be polished.An example of the shape of the specimen prism is shown in Figure 3. The optimum apex angle (such that error in measurement of the apex angle is least severe
34、) for a material of the relative refractive index nrelis = 2arctan(1/nrel) (2)For low index materials, this relation can result in undesirably large apex angles; this relation shall be used as guidance.ABRL1CA, C = 90 0 2 30B, C = 90 0 2 30Key1 chamferRL ridge line apex angle of the specimen prismFi
35、gure 3 Shape of the specimen prism5.2 Surface accuracyThe surface accuracy of the entrance face and the exit face of the specimen prism shall be measured with an interferometer. Any measured power term shall not be subtracted from measurement data. A surface flatness error should be 150 nm P-V or le
36、ss over the entire clear aperture of the specimen prism faces.6 Test reportThe test report shall specify the following:a) specimen name in accordance with ISO 11382:2010, 5.6;4 ISO 2014 All rights reservedBS ISO 17328:2014ISO 17328:2014(E)b) date, place, measurers name;c) temperature, humidity, air
37、pressure of ambient air;d) apex angle of the specimen prism;e) temperature of the specimen prism;f) surface accuracy of the entrance face and the exit face;g) wavelengths and bandwidth (full width at half maximum) of wavelengths for measurement;h) angles of minimum deviation;i) relative refractive i
38、ndices to the air.Values of c), d), e), g), h), and i) shall be specified with values of uncertainty. ISO 2014 All rights reserved 5BS ISO 17328:2014ISO 17328:2014(E)Annex A (informative) Apparatus for measurementA.1 GeneralExamples of apparatus for measurement of the relative refractive index and t
39、he measurement procedure are described.In the measurement room, air temperature, pressure and humidity, and the temperature of the specimen prism are kept at specified values during the measurement time.A.2 Apparatus for measurementThe apparatus is composed of those parts in Figure A.1. It is shown
40、in a configuration that uses a monochromator. However, the monochromator can be replaced with another wavelength selecting unit.LSRO SLPMGRPMCCMCCMMCMSLPMCMMSPRSGMRAFMPMDUFUCMUKeyLS light sourceRO relay opticsSL slitPM plane mirrorCCM concave mirrorGR gratingMCM monochromatorCMU collimating unitCMM
41、collimating mirrorSP specimen prismRS rotating stageGM goniometerRA rotating armFU focusing unit6 ISO 2014 All rights reservedBS ISO 17328:2014ISO 17328:2014(E)FM focusing mirrorDU detector unitNOTE Arrows indicate rotation of rotating stage and rotating arm.Figure A.1 Outline of configurationA.2.1
42、Light sourceThe light source emits the light which includes the spectrum of measurement wavelengths.A.2.2 Wavelength selecting unitThe wavelength selecting unit selects a desired light from a slit or from a pinhole that is located at the focus of the collimating unit.The grating monochromator is a p
43、art for selecting the monochromatic light beam of desired wavelength from the light source.The light beam from the light source enters the grating monochromator through the entrance slit or the entrance pinhole, and the monochromatic light beam of selected wavelength is passed through the exit slit
44、or the exit pinhole.The optical systems of the grating monochromator are composed of the reflecting optical components to make the grating monochromator operational in the wide spectral range. The calibration light beams are the monochromatic emission lines which wavelengths are known accurately. Th
45、e calibration light beams are applied to the calibration of the wavelength-counter of the grating monochromator.The light beam from the light source and the calibration light beam are transmitted at the same position on the entrance slit and the exit slit of the grating monochromator.Band-pass filte
46、r can also be used as wavelength selecting units.NOTE 1 Some bandpass filters shift their centre wavelengths with temperature.NOTE 2 The wavelength of the light beam exiting from the grating monochromator changes along with the longitudinal direction of the slit.A.2.3 Collimating unitThe collimating
47、 unit is a unit for collimating the monochromatic light beam from the entrance slit or from the entrance pinhole of the wavelength selecting unit. It consists of reflecting optics to avoid errors caused by chromatic aberration of the optics.A.2.4 GoniometerThe goniometer consists of a rotating stage
48、 and a rotating arm. It has a function for reading a rotation angle of the rotating arm. The rotating stage holds the specimen prism at the position where the entrance face of the specimen prism is illuminated by the monochromatic light beam from the collimating unit and rotates the specimen prism.
49、The rotating arm rotates a focusing unit and a detector unit.The rotating axis of the rotating stage and the rotating axis of the rotating arm are parallel to the ridge line defined by the entrance face and the exit face of the specimen prism. The holder of the specimen prism has an adjusting mechanism for tilting.The plane of section, PS, of the specimen prism is maintained parallel to the monochromatic light beam. The plane, PS, is defined as a plane normal to the ridge line of the
