1、BRITISH STANDARD Optical fibre amp li fiers Basic specirication Part 5-3: Test methods for reflectance parameters - Reflectance tolerance using an electrical spectrum analyser The European Standard EN 61290-5-3:2002 has the status of a British Standard ICs 33.180.30 BS EN 6 1290-5-3 12002 British St
2、andards NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 61290-5-312002 National foreword This British Standard is the official English language version of EN 61290-5-3:2002. It is identical with IEC 61290-5-3:2002. The UKparticipation in its preparation was entrusted by
3、Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/3, Fibre optic systems and active devices, which has the responsibility to: This British Standard, having been prepared under the direction of the Electrotechnical Sector Policy and Strategy Committee, was published under the authority
4、 of the Standards Policy and Strategy Committee on 22 July 2002 - - aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and Eu
5、ropean developments and promulgate 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-
6、1. For a period oftime during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cros s-r e ferenc es The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalog
7、ue under the section entitled “International Standards Correspondence Index”, or by using the “Search”faci1ity ofthe BSI Electronic Catalogue or of British Standards Online This publication does not purport to include all the necessary provisions of a contract. Users are responsible for their correc
8、t application. Compliance with a British Standard does not ofitself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 12, an inside back cover and a back cover. The BSI copyright date displayed in this
9、 document indicates when the document was last issued. Amendments issued since publication Amd.No. I Date I Comments O BSI 22 July 2002 ISBN O 580 40079 4 EUROPEAN STANDARD EN 61290-5-3 NORME EUROPENNE EUROPISCHE NORM April 2002 ICs 33.180.30 English version Optical fibre amplifiers - Basic specific
10、ation Part 5-3: Test methods for reflectance parameters - Reflectance tolerance using an electrical spectrum analyser (IEC 61290-5-312002) Amplificateurs fibres optiques - Spcification de base Partie 5-3: Mthodes dessai des paramtres de rflectance - Tolrance de rflectance en utilisant un analyseur d
11、e spectre lectrique (CE1 61290-5-312002) L ic h twe I le n le i te r-Ve rs t r ke r - G ru nds pezifi kat ion Teil 5-3: Prfverfahren fr Reflexionsparameter - Zu I ss i g e RU c kf I ussd m pf u n g unter Verwendung elektrischer S pe ktralanalysatoren (I EC 61 290-5-312002) This European Standard was
12、 approved by CENELEC on 2002-04-01. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such
13、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 version in any other language made by translation under the responsibility of a CENELEC member into its own lan
14、guage 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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Po
15、rtugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels O 2002 CENELEC - All righ
16、ts of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61290-5-3:2002 E Page 2 EN 61290-5-32002 Foreword The text of document 86C/390/FDIS, future edition 1 of IEC 61290-5-3, prepared by SC 86C, Fibre optic systems and active devices, of IEC TC 86, Fibre
17、optics, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61290-5-3 on 2002-04-01. The 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 - latest date by
18、which the national standards conflicting with the EN have to be withdrawn Annexes designated “normative“ are part of the body of the standard. Annexes designated “informative“ are given for information only. In this standard, annex ZA is normative and annex A is informative. Annex ZA has been added
19、by CENELEC. (dop) 2003-01-01 (dow) 2005-04-01 Endorsement not i ce The text of the International Standard IEC 61290-5-3:2002 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indi
20、cated : IEC 60825-1 NOTE Harmonized as EN 60825-1:1994 (not modified) IEC 60825-2 NOTE Harmonized as EN 60825-2:2000 (not modified) IEC 60874-1 NOTE Harmonized as EN 60874-1:1999 (not modified) O BSI 22 July 2002 Page 3 EN 61290-5-32002 CONTENTS INTRODUCTION . 4 1 Scope and object 5 2 Normative refe
21、rences 5 3 Apparatus 6 4 Test sample 6 5 Procedure . 7 5.1 Calibration . 7 5.2 Measurements and computation 7 6 Test results 9 Annex A (informative) List of abbreviations 10 Annex ZA (normative) Normative references to international publications with their corresponding European publications 12 Bibl
22、iography 11 Figure 1 . Measurement configuration for maximum reflectance tolerable at input and output 6 Figure 2 . Measurement configuration for maximum reflectance tolerable at input . 8 Figure 3 . Measurement configuration for maximum reflectance tolerable at output . 9 O BSI 22 July 2002 Page 4
23、EN 61290-5-32002 INTRODUCTION As far as can be determined, this is the first International Standard on optical fibre amplifiers. This technology is quite new and still emerging, hence amendments and new editions to this standard can be expected. Each abbreviation introduced in this International Sta
24、ndard is explained in the text at least the first time that it appears. However, for an easier understanding of the whole text, a list of all abbreviations used is given in annex A. This standard should be read in conjunction with IEC 61290-3-2 and IEC 61291-1. O BSI 22 July 2002 Page 5 EN 61290-5-3
25、2002 OPTICAL FIBRE AMPLIFIERS - BASIC SPECIFICATION - Part 5-3: Test methods for reflectance parameters - Reflectance tolerance using an electrical spectrum analyser 1 Scope and object This part of IEC 61290 applies to optical fibre amplifiers (OFAs) using active fibres, containing rare-earth dopant
26、s, presently commercially available. The object of this International Standard is to establish uniform requirements for accurate and reliable measurements, by means of the electrical spectrum analyser test method, of the following OFA parameters, as defined in clause 3 of IEC 61291-1: a) maximum ref
27、lectance tolerable at input b) maximum reflectance tolerable at output c) maximum reflectance tolerable at input and output NOTE All numerical values followed by ($) are currently under study A measurement accuracy for reflectance tolerable of k0,5 dB should be attainable with this method. The prese
28、nt test method uses the noise figure as the measure of the “tolerance” against reflectance at each port of the OFA. This is because the (total) noise figure of the OFA may significantly degrade due to the multiple-interference if reflectance at one or both of each OFA port exists. 2 Normative refere
29、nces The following referenced documents are indispensable for the application 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 61290-3, Opfical fibre amplifiers - Basi
30、c specificafion - Parf 3: Tesf mefhods for noise figure paramefers IEC 61290-3-2, Opfical fibre amplifiers - Basic specificafion - Parf 3-2: Tesf mefhods for noise figure paramefers - Elecfrical specfrum analyser fesf mefhod 1 IEC 61291-1 :1998, Opfical fibre amplifiers - Parf 1: Generic specificafi
31、on 1 To be published O BSI 22 July 2002 Page 6 EN 61290-5-32002 Tx dB 3 Apparatus isolator + R Polarization controller A scheme of the measurement set-up is shown in figure 1 Variable Variable input reflector 4 Optical attenuator Modulator isolator 4 R Polarization - ESA Figure 1 - Measurement confi
32、guration for maximum reflectance tolerable at input and output controller dB - The same test equipment and required characteristics as those of IEC 61290-3-2 shall be used in addition to the following. a) Variable reflector(s) which generate reflectances from -55 dB(3) to -8,5 dB(3) with insertion l
33、oss variation k0,05 dB (when set at any reflectance). A variable reflector can consist of an optical splitter with a variable attenuator and highly reflective mirror at one output port (to reflect a portion of the power), with the other output port to be connected to the remainder of the measurement
34、 configuration. It also can consist of an optical splitter with a variable attenuator in a “loop” configuration at one output port (this has an optical directional coupler “return” the attenuated optical power to the “input port”), with the other output port to be connected to the remainder of the m
35、easurement configuration. Note that there are other options. b) Optical isolators to ensure variable reflectors and other reflections have no influence on the relative intensity noise (RIN) produced by the test configuration. These isolators shall have an optical isolation of better than 55 dB(3) an
36、d reflectances at each port -55 dB(3). 4 Test sample The OFA shall operate at nominal operating conditions. Care shall be taken in maintaining the state of polarization of the input light after it is adjusted to the maximum reflectance possible. Changes in the polarization state may result in change
37、s in the gain as well as in the noise due to multipath interference. NOTE 1 The output reflectance test procedure should only be performed on OFAs that have the complete optics (.e., have sufficient attenuation in the direction opposite the signal). This measurement is of little or no value for OFA
38、devices that do not have all the optics for “black-box” OFA ready for use in an optical communications system. NOTE 2 The maximum reflectance tolerable at each port may depend on the optical gain and consequently on the signal power and pump power. NOTE 3 The line width of the optical source shall n
39、ot be too narrow to let the interferometric signal due to multiple reflections affect the measurements. NOTE 4 Polarization dependence of the reflection parameters is not considered as important as the magnitude of the reflection. O BSI 22 July 2002 Page 7 EN 61290-5-32002 5 Procedure All noise meas
40、urements are to be made as a function of baseband frequency, in other words the modulation frequency of the laser source. One may perform these measurements: (1) over a range of frequencies specified in the detailed specification (for example, from 10 MHz to 2 GHz in steps of 5 MHz) or (2) at two to
41、 five frequencies as specified in the detailed specification. It is assumed that all OFA NF specifications include the “worst-case” scenario (.e., minimum input signal power, a certain wavelength, lowest modulation frequency IO MHz($) and linewidth 20 MHz($). In some cases, multiple reflections with
42、in an OFA can cause multipath interference (mpi) (see IEC 61290-3). This test procedure deals with the increase in this “mpi” noise factor contribution (due to the presence of external reflections). To ensure accuracy and repeatability of this procedure, the maximum noise factor contribution from mp
43、i fmpi-max (yn ,u,fworst-case, Auworst-case), as specified at the “worst-case” frequency and linewidth, shall be translated into the fmpi(P,n,u,fmeas,Aumeas)that results from the same “effective” reflective cavity at the qOw and AU, of the measurement configuration. Another method of performing this
44、 “translation” is to determine the mpi figure of merit - lmpi that creates Fmpi-max(P;n ,u,fworst-case,Auworst-case). The measurement essentially determines the magnitude of the reflectances at input port, output port, or both ports simultaneously, that can generate the specified total noise figure
45、at the “worst-case” frequency and linewidth. 5.1 Calibration Follow the calibration procedure given in 5.1 of IEC 61290-3-2. 5.2 Measurements and computation a) Maximum reflectance tolerable at input and output 1) With a variable optical attenuator (input attenuator), isolator, polarization controll
46、er and variable reflector after the optical transmitter, set the input signal power to the OFA, as specified in the relevant detailed specification ( yn). Check this power with an optical power meter. 2) Insert OFA (figure I), a second polarization controller, a second variable reflector, and a seco
47、nd variable attenuator (output attenuator) prior to the receiver. Set variable reflectors initially to RI = R2 -55 dB($) where RI and R2 are the reflectances 3) Perform the procedure according to 5.2 of IEC 61290-3-2. From these measurements, the frequency independent contribution to the noise facto
48、r ( non-mpi) and mpi figure of merit ( lmpi ) can be determined. 4) When external reflectances are present, their influence on non-mpi will be negligible compared to the effects on lmpi. Assuming non-mpi is constant, determine the minimum lmpi that could create the “worst-case” noise factor specifie
49、d at the lowest modulation frequency I O MHz($), and linewidth 20 MHz($): O BSI 22 July 2002 Page 8 EN 61290-5-32002 i 2 - 7 fworst-case worst-case i Auworst-case lmpi = (Fworst-case - Fnon-mpi 1 T. where I is the figure of merit; F is the noise factor; f is the modulation frequency; mpi is the multipath interference; u is the optical frequency. 5) Determine the “worst-case” noise factors at the modulation frequencies (indicated in the detailed specification) and linewidth of the measurement configuration: 2Impi Aumeas + f:eas + AUieas j Fwors
