1、 IEC 60793-1-61 Edition 1.0 2017-02 INTERNATIONAL STANDARD Optical fibres Part 1-61: Measurement methods and test procedures Polarization crosstalk IEC 60793-1-61:2017-02(en) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2017 IEC, Geneva, Switzerland All rights reserved. Unless otherwise specifi
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10、ish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csciec.ch. IEC 60793-1-61 Edition 1.0 2017-02 INTERNATIONAL STANDARD Optical fibres Part 1-61: Measurement methods and test procedures Polarization crosstalk INTERNATIONAL ELECTRO
11、TECHNICAL COMMISSION ICS 33.180.10 ISBN 978-2-8322-3867-7 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. 2 IEC 60793-1-61:2017 IEC 2017 CONTENTS FOREWORD . 3 1 Scope 5 2 Normative references
12、5 3 Terms and definitions 5 4 Test conditions 5 5 Reference test method 6 6 Test methods . 6 6.1 Method A: Power ratio method 6 6.1.1 Overview of the method . 6 6.1.2 Application . 6 6.1.3 Test apparatus 6 6.1.4 Test procedure 7 6.2 Method B: In-line polarimetric method . 8 6.2.1 General . 8 6.2.2 L
13、imitations of the method . 8 6.2.3 Measurement process . 8 6.2.4 Mathematical basis 9 7 Results 10 7.1 Information available with each measurement . 10 7.2 Information available upon request . 10 Figure 1 Example of test apparatus for polarization crosstalk measurement (power ratio method) 6 Figure
14、2 Poincar sphere representations for Method B . 9 IEC 60793-1-61:2017 IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ OPTICAL FIBRES Part 1-61: Measurement methods and test procedures Polarization crosstalk FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organiz
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24、8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent ri
25、ghts. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 60793-1-61 has been prepared by subcommittee 86A: Fibres and cables, of IEC technical committee 86: Fibre optics. The text of this International Standard is based on the following docume
26、nts: CDV Report on voting 86A/1739/CDV 86A/1781/RVC Full information on the voting for the approval of this International Standard can be found in the report on voting indicated in the above table. This document has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts
27、in the IEC 60793 series, published under the general title Optical fibres, can be found on the IEC website. 4 IEC 60793-1-61:2017 IEC 2017 The committee has decided that the contents of this document will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.ie
28、c.ch“ in the data related to the specific document. At this date, the document will be reconfirmed, withdrawn, replaced by a revised edition, or amended. A bilingual version of this publication may be issued at a later date. IEC 60793-1-61:2017 IEC 2017 5 OPTICAL FIBRES Part 1-61: Measurement method
29、s and test procedures Polarization crosstalk 1 Scope This part of IEC 60793 establishes uniform requirements for measuring the polarization crosstalk of polarization-maintaining (PM) fibres. This document gives two methods for measuring the polarization crosstalk of PM fibres. Method A is the power
30、ratio method, which uses the maximum and minimum values of output power at a specified wavelength, and Method B is the in-line method, which uses an analysis of the Poincar sphere. Details of each method are described in Clause 6. Crosstalk values obtained by Methods A and B are based on different d
31、efinitions. The crosstalk measured by Method A is defined as an “averaged“ value over a measured wavelength range. In contrast, the crosstalk value obtained from Method B shows the “worst case“ crosstalk value. 2 Normative references The following documents are referred to in the text in such a way
32、that some or all of their 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. IEC 60793-1-1, Optical fibres Part 1-1: Measurement methods and
33、 test procedures General and guidance IEC 60793-2-70 1 , Optical fibres Part 2-70: Product specifications Sectional specifications for polarization-maintaining fibres IEC 60068-1, Environmental testing Part 1: General and guidance 3 Terms and definitions For the purposes of this document, the terms
34、and definitions given in IEC 60793-1-1 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 4 Test conditions Unless othe
35、rwise specified, the test shall be conducted under the standard conditions specified in IEC 60068-1. However, when it is difficult to make measurements under the standard conditions, the test may be conducted under conditions other than the standard conditions, provided that no doubts will arise abo
36、ut judgments. _ 1Under preparation. Stage at the time of publication: IEC CCDV 60793-2-70:2017. 6 IEC 60793-1-61:2017 IEC 2017 5 Reference test method Since the “averaged“ polarization crosstalk value measured by Method A is the parameter specified in the product specification, IEC 60793-2-70 2 , Me
37、thod A is the reference test method (RTM), which shall be the one used to settle disputes. 6 Test methods 6.1 Method A: Power ratio method 6.1.1 Overview of the method Method A is applicable to PM fibres, fibres having connectors attached to one or both ends of the fibres, and to two or more such en
38、tities joined in series. Adjust the optical output to the minimum by rotating both the polarizer and analyser, and measure the optical output as P min . Rotate the analyser 90 and measure the optical output as P max . Calculate the polarization crosstalk with the second set of values and take the av
39、erage of the two values as the measured value. 6.1.2 Application This measuring method shall be applied to the measurement of polarization crosstalk using the maximum and minimum values of optical output at a specified wavelength. 6.1.3 Test apparatus 6.1.3.1 Principle Figure 1 shows an example of a
40、 test apparatus. Figure 1 Example of test apparatus for polarization crosstalk measurement (power ratio method) 6.1.3.2 Light source The light source to be used shall be one with a specified wavelength and wide spectrum bandwidth (20 nm or more at FWHM), or alternatively, its coherence length (l c )
41、 shall be appropriately short for the sample under test. B c 10 1 L L l (1) where L is the sample length; L B is the fibres beat length; is the source centre wavelength. A LED (light emitting diode) light source or an SLD (super-luminescent diode) light source is recommended for this test. The sourc
42、e power shall be kept below the level required to induce non-linear propagation effects; 10 mW is typically a safe limit. For a LED light source, whose power is low, however, a high-sensitivity detector shall be used. _ 2Under preparation. Stage at the time of publication. IEC CCDV 60793-2-70:2016.
43、IEC Light source Depolarizer Polarizer Input optics Sample under test Analyzer Detector Output optics IEC 60793-1-61:2017 IEC 2017 7 6.1.3.3 Input and output optics The input and output optics shall be relatively strain free, as mounted. Cladding mode should be minimized at the input end by carefull
44、y launching to the fibre to be tested. Cladding mode stripping by bending sometimes causes the deterioration of crosstalk by the bend, therefore it is recommended to avoid it. 6.1.3.4 Detector The detector to be used shall have a light receiving area that can detect all the optical power emitted fro
45、m the output end of the optical fibre. A power meter combining a photo-detector and an electronic processing system can also be used. The detector response (including supplemental equipment such as a lock-in amplifier) shall be linear to within 5 % from the minimum to the maximum measured power and
46、independent of the input polarization state. 6.1.3.5 Depolarizer When the input light from the light source is polarized, a depolarizer shall be provided to enable the input of a certain level of optical power into the optical fibre even when the polarizer is rotated. Alternatively, a polarization c
47、ontroller could be used for depolarizing, instead of the depolarizer. 6.1.3.6 Polarizer and analyser A linear polarizer is an optical device capable of outputting linearly polarized light having a certain direction of electric field vector when it has received light in an arbitrary state of polariza
48、tion. The polarizer to be used shall have a polarisation extinction ratio (PER) sufficient for measuring the polarization crosstalk of the optical fibre under test. The PER of the polarizer and of the analyser should be at least 10 dB higher than the maximum expected crosstalk. 6.1.4 Test procedure
49、6.1.4.1 Preparation In the case of fibres, prepare a V-groove or bare fibre adapter to connect the polarizer, the analyser and the optical fibre under the test. Remove the primary coating from both ends of the known length of the optical fibre under the test, and cleave the ends into mirror surfaces perpendicular to the axis of the optical fibre. Connect the polarizer with one end of the optical fibre, using a V-groove or similar means. Connect the other end o
