1、STD-BSI BS EN bL300-3-40-ENGL 1798 LbZLIbbS 0730435 335 BRITISH STANDARD Fibre optic interconnecting devices and passive components - Basic test and measurement procedures - Part 3-40 Examinations and measurements - Extinction ratio of a polarization maintaining (pm) fibre pigtailed connector The Eu
2、ropean Standard EN 613-3-401998 has the status of a British Standard ICs 33.180.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 613OO-3-40 1998 EC 61300-3-40 1998 STD.BSI BS EN bL300-3-YO-ENGL 1998 Lb2LibbS 071043b 1151 Amd. No. Date BS EN 613003-401998 Text affected
3、National foreword This British Standard is the English language version of EN 6130W1998. It is identical with IEC 613W3401998. The UK participation in its preparation was entrusted by Technical Committee EPL/86, Fibre optics, to Subcommittee EPI86/2, Interconnecting devices and passive components, w
4、hich has the responsibility to: - aid enquirers to understand the text; - present to the responsible internationaVEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed - monitor related international and European developments and promulga
5、te them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. From 1 January 1997, all IEC publications have the number 60000 added to the old number. For instance, IEC 27-1 has been renumbered as IEC 60027-1. For a period of time during the
6、 change over from one numbering system to the other, publications may contain identifiers from both systems. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their correspondin
7、g European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index“, or by using the “Find“ facility of the BSI Standards Electronic Catalogue
8、. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligatians. Summary of pages This document comprise
9、s a front cover, an inside front cover, the EN title page, pages 2 to 6, an inside back cover and a back cover. This British Standard, having been prepared under the direction of the Elecrotechnicai Sector Board, was published under the authority of the Standards Board and comes into effect on 15 Ju
10、iy 1998 O BSI 1998 ISBN O 580 30116 8 - - STD.BSI BS EN b130D-3-VO-ENGL 1998 lib24bb9 0710437 T98 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61 300-3-40 April 1998 ICs 33.180.20 English version Fibre optic interconnecting devices and passive components Basic test and measurement procedures
11、 Part 3-40: Examinations and measurements Extinction ratio of a polarization maintaining (pm) fibre pigtailed connector (IEC 61 300-3-40: 1 998) Dispositifs dinterconnexion et composants passifs fibres optiques Mthodes fondamentales dessais et de mesures Partie 3-40: Examens et mesures Rapport dexti
12、nction dun connecteur fibre amorce maintenant la polarisation (pm) (CE1 61 300-3-40: 1 998) Lichtwellenleiter-Verbindungselemente und passive Bauteile Grundlegende Prf- und Meverfahren Teil 3-40: Untersuchungen und Messungen - Messung der Verminderung des Extinktions- Verhltnisses eines Steckverbind
13、ers mit einer polarisationserhaltenden (PM) Anschlufaser (IEC 61 300-3-40: 1998) This European Standard was approved by CENELEC on 1998-04-01. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a
14、 national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A vers
15、ion in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Den
16、mark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotec
17、hnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 1998 CENELEC - All rights of exploitation m any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 6 1 300-3-40: 1998 E STD.BSI BS EN b1300-3-q-ENGL 1798 1bZqbb9 07LOLi38 92q Page 2 EN 61300-3-40:1998 F
18、oreword The text of document 86B/1040/FDIS, future edition 1 of IEC 61 300-3-40, prepared by SC 86B, Fibre optic interconnecting devices and passive components, of IEC TC 86, Fibre optics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61 300-3-40 on 1998-04-01. The
19、 following dates were fixed: - latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement with the EN have to be withdrawn - latest date by which the national standards conflicting (dopl 1999-01 -01 (daw) 200 1 -0 1 -0 1 End
20、orsement notice The text of the International Standard IEC 61 300-3-40: 1998 was approved by CENELEC as a European Standard without any modification. FIBRE OPTIC INTERCONNECTING DEVICES AND PASSIVE COMPONENTS - BASIC TEST AND MEASUREMENT PROCEDURES - Part 3-40: Examinations and measurements - Extinc
21、tion ratio of a polarization maintaining (pm) fibre pigtailed connector 1 General 1.1 Scope and object This part of IEC 61300 describes the procedure to measure the ability of an optical fibre connector to maintain a given extinction ratio across the connection in pm fibre. In this test we limit the
22、 measurement to the most common case of nearly linearly polarized light propagating in pm fibre. The term extinction ratio“ used here refers to the proportion of light propagating in the two orthogonal polarization axes of the fibre and is more properly defined as “polarization crosstalk“. Extinctio
23、n ratio“ is the commonly used term. This procedure has been designed for use with dedicated equipment in a manufacturing environment and thus incorporates a rather elaborate test configuration. It should be noted that other more direct test configurations can be used in suitably equipped optical lab
24、oratories. These may be the subject of additional test procedures in the future. It should be noted that this test procedure is not designed for long term continuous testing; drift of polarization alignment can occur particularly in the single-mode fibre. Hence, repeated rather than continuous measu
25、rement is required for long term testing of components. 1.2 General description Polarization maintaining fibre has the ability to maintain the proportions of light polarized parallel to the two axes of symmetry of the fibre even when there is moderate bending of the fibre. A connector system intende
26、d for use with pm fibre should accordingly create minimum disturbance to this proportioning of the propagating light. In the case of light highly polarized along one axis of the fibre the ratio of these two portions of the light is called the extinction ratio and is usually expressed in decibels. A
27、connector can degrade the extinction ratio in two ways. Firstly, the connector can have non-ideal keying so that the two ends of the fibres being joined are not perfectly aligned with respect to their axes of birefringence. Secondly, the connector-to-fibre fixing mechanism can cause distortions or n
28、on-symmetrical stresses to the fibre which result in extinction ratio degradation. This test is intended to measure the extinction ratio for connectors in which the former mechanism is the dominant source of extinction ratio degradation. The degree to which the latter mechanism affects the extinctio
29、n ratio must be measured during the pigtailing process and hence would be applicable to field mountable pm fibre connectors or to the assembly process at the connector pigtail manufacturers location. STD.BSI BS EN b1300-3-40-ENGL 1998 lb24bb9 07104LiO 582 9 Page 4 EN 61300-3-401998 2 Apparatus The a
30、pparatus and arrangement necessary to make this measurement is shown in figure 1. It consists of: - an optical source, S of known characteristics (wavelength, spectral width, etc.) and a compatible detector, D. The accuracy of this test will be affected by interference effects among elements of the
31、test apparatus and the device under test and therefore care should be taken on the coherence of the light source. This test procedure requires that the light source has a low degree of coherence since use of a highly coherent source, such as a DFB laser, can produce false measurement results. A Fabr
32、y-Perot laser with three or more primary longitudinal modes of oscillation is suitable for this test. Ideally, an LED is the preferred source if the spectral characteristics of the test component and the dynamic range of the measurement required can accommodate this type of source. Specifically, the
33、 source must launch enough power into the fibre so that the minimum signal measured through the test component is at least 3 dB higher than the noise floor of the detector; - an in-line polarization assembly of polarizer, quarter-wave retardation plate and half-wave retardation plate in an expanded
34、beam formed by two lenses L1 and L2. The polarizer linearly polarizes the light to a high extinction ratio; the quarter-wave plate converts the state of polarization (SOP) from linear to elliptical or circular; and the half-wave plate rotates the direction of polarized light. With this combination o
35、f elements, it can be seen that every possible SOP can be produced; - a temporary joint, TJ; - a reference pm fibre pigtail. This could be a pigtail of the type to be measured which has previously been determined to be accurate (tolerances to be specified in relevant specification) dimensionally (ke
36、ying, core alignment, etc.); - an analyzer, A, to determine the extinction ratio of light. The polarization optics described in this test procedure is based on bulk optical elements; .e. waveplates and a polarizer. It is also permissible to assemble the polarization optics by other means such as fib
37、re loop polarization elements. Comment on apparatus: the purpose of the section of sm fibre at the output of the polarization optics is to facilitate an optical joint to a variety of reference pm fibre pigtails. It is also permitted to eliminate this section of sm fibre and replace it with a direct
38、coupling of the polarization optics to the reference pm pigtail. Furthermore, since the presence of cladding modes will degrade the accuracy of measurement, it is assumed that the fibre jacket for all singie-mode and pm fibre sections acts as a cladding mode stripper. 3 Procedure The first part of t
39、his procedure sets a high degree of linear polarization aligned to a fibre polarization axis at the output of the reference pigtail connector. During this procedure care should be taken not to move the singlemode fibre sections of the arrangement. With the measurement arrangement set up as in figure
40、 1: Fibre sm POL O0 144 II2 Fibre sm - Reference pigtail IEC 15a%8 Figure 1 - Measurement Set-up: reference measurement STD-BSI BS EN b1300-3-40-ENGL 1998 Lb29bb 07LOLiLiL 419 Page 6 EN 61300-3-40:1998 a) with arbitrary settings of the quarter and half-wave retardation plates and the analyzer adjust
41、 the polarizer to get a maximum measurement at the detector; b) adjust analyzer, A, to get a minimum measurement at the detector; c) adjust quarter-wave plate to get minimum measurement at the detector; d) adjust half-wave plate to get minimum measurement at the detector; e) repeat steps b), c) and
42、d) until the lowest measurement attainable is achieved (two or three iterations). Record this measurement as DMIN, (dem). At this point of the procedure a check on the polarization alignment can be made by inducing gentle bending and twisting motion in the test pigtail while monitoring the power met
43、er. Power fluctuations of greater than 1 dB indicate that the polarization alignments to the principal axes are not correct and realignment is necessary; f) adjust the analyzer to obtain a maximum reading at the detector. Record this reading as DMAXi (dem). The initial extinction ratio of the light,
44、 Ri , is given by OMAX, - DM/Ni (dB). Since this value is a limit to the measurement range of the system, it is normal to require that this value be 10 dB greater than the maximum expected measurement of the extinction ratio made on the test pigtail. The next part of this procedure measures the degr
45、ee of linear polarization as an extinction ratio after the connection to the pigtail to be evaluated. A comparison to the initial extinction ratio will give the degradation in extinction ratio. Taking care not to disturb the singlemode fibre parts of the arrangement, connect the pigtail to be tested
46、 to the reference connector and mate the fibre end (properly cleaved) or the connector (in the case of a patchcord) to the analyzer as shown in figure 2. TJ A IC Fibre prn Reference Test pigtail pigtail Fibre sm POL 114 1l2 - - pl0U1-1 x- IEC 159B8 Figure 2 - Measurement set-up g) adjust the analyze
47、r to obtain a minimum reading at the detector. Record this reading as DMINf (dem). h) adjust the analyzer to obtain a maximum reading at the detector. Record this reading as DMAXf (dem). The final extinction ratio of the light, ERf, is given by DMAXf - MIN, (dB). The change in the extinction ratio,
48、ER, - ERf, gives the extinction ratio caused by the polarization maintaining fibre pigtail, in combination with the reference connector. Since this test will give results dependent on the particular alignment of the keying, repeated measurements will normally be made to determine the performance of
49、a connector pigtail. STD-BSI BS EN bL300-3-40-ENGL 1798 lb24bb7 07304q2 355 Page 6 EN 61300-3-40:1998 4 Details to be specified The following details, as applicable, shall be specified in the relevant specification. - source S including spectral width or coherence length, stability and peak wavelength; - relevant performance details of the in-line polarization assembly; - accuracy of alignment of the axes of the pm fibre to the key of the reference plug and other requirements for the reference plug; - detector spectral response; - detector linearity;
