1、BRITISH STANDARD BS EN 61290-5-3:2002 Optical fibre amplifiers Basic specification 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 61290-5-3:
2、2002 This British Standard, having been prepared under the direction of the Electrotechnical Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 22 July 2002 BSI 22 July 2002 ISBN 0 580 40079 4 National foreword This British Stand
3、ard is the official English language version of EN 61290-5-3:2002. It is identical with IEC 61290-5-3:2002. The UK participation in its preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/3, Fibre optic systems and active devices, which has the responsibilit
4、y to: 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 change over
5、from one numbering system to the other, publications may contain identifiers from both systems. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Stand
6、ards Correspondence Index”, or by using the “Search” facility of the 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 correct application. Compliance with a British Standar
7、d does not of itself confer immunity from legal obligations. 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 European
8、developments and promulgate them in the UK. 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 document indicates when the document was last issued. Amendment
9、s issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 61290-5-3 NORME EUROPENNE EUROPISCHE NORM April 2002 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretar
10、iat: rue de Stassart 35, B - 1050 Brussels 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61290-5-3:2002 E ICS 33.180.30 English version Optical fibre amplifiers - Basic specification Part 5-3: Test methods for reflectance p
11、arameters - Reflectance tolerance using an electrical spectrum analyser (IEC 61290-5-3:2002) Amplificateurs fibres optiques - Spcification de base Partie 5-3: Mthodes dessai des paramtres de rflectance - Tolrance de rflectance en utilisant un analyseur de spectre lectrique (CEI 61290-5-3:2002) Licht
12、wellenleiter-Verstrker - Grundspezifikation Teil 5-3: Prfverfahren fr Reflexionsparameter - Zulssige Rckflussdmpfung unter Verwendung elektrischer Spektralanalysatoren (IEC 61290-5-3:2002) This European Standard was approved by CENELEC on 2002-04-01. CENELEC members are bound to comply with the CEN/
13、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 Central Secretariat or to a
14、ny 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 language and notified to the Central Secretariat has the same status as the official ve
15、rsions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Foreword The text of document
16、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 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
17、EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2003-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2005-04-01 Annexes designated “normative“ are part of the body of the standard
18、. 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 by CENELEC. _ Endorsement notice The text of the International Standard IEC 61290-5-3:2002 was approved by CENELEC as a European Standard wit
19、hout any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: 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:
20、1999 (not modified). _ BSI22July2002 Page2 EN6129053:2002 CONTENTS INTRODUCTION.4 1 Scope and object5 2 Normative references5 3 Apparatus.6 4 Test sample6 5 Procedure.7 5.1 Calibration.7 5.2 Measurements and computation 7 6 Test results 9 Annex A (informative) List of abbreviations10 Annex ZA (norma
21、tive) Normative references to international publications with their corresponding European publications12 Bibliography11 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
22、3 Measurement configuration for maximum reflectance tolerable at output .9 BSI22July2002 Page3 EN6129053:2002 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 edit
23、ions to this standard can be expected. Each abbreviation introduced in this International Standard 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 r
24、ead in conjunction with IEC 61290-3-2 and IEC 61291-1. BSI22July2002 Page4 EN6129053:2002 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 op
25、tical fibre amplifiers (OFAs) using active fibres, containing rare-earth dopants, 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
26、following OFA parameters, as defined in clause 3 of IEC 61291-1: a) maximum reflectance 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 re
27、flectance tolerable of 0,5 dB should be attainable with this method. The present 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-interfer
28、ence if reflectance at one or both of each OFA port exists. 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 latest edition of the referenced document (i
29、ncluding any amendments) applies. IEC 61290-3, Optical fibre amplifiers Basic specification Part 3: Test methods for noise figure parameters IEC 61290-3-2, Optical fibre amplifiers Basic specification Part 3-2: Test methods for noise figure parameters Electrical spectrum analyser test method 1 IEC 6
30、1291-1:1998, Optical fibre amplifiers Part 1: Generic specification _ 1To be published BSI22July2002 Page5 EN6129053:2002 3 Apparatus A scheme of the measurement set-up is shown in figure 1. Tx dB Optical isolator R OA dB Receiver Modulator ESA R Variable input attenuator Variable output attenuator
31、Polarization controller Variable reflector Optical isolator Variable reflector Polarization controller IEC 612/02 Figure 1 Measurement configuration for maximum reflectance tolerable at input and output The same test equipment and required characteristics as those of IEC 61290-3-2 shall be used in a
32、ddition to the following. a) Variable reflector(s) which generate reflectances from 55 dB() to 8,5 dB() with insertion loss variation 0,05 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 p
33、ort (to reflect a portion of the power), with the other output port to be connected to the remainder of the measurement 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”
34、the attenuated optical power to the “input port”), with the other output port to be connected to the remainder of the measurement configuration. Note that there are other options. b) Optical isolators to ensure variable reflectors and other reflections have no influence on the relative intensity noi
35、se (RIN) produced by the test configuration. These isolators shall have an optical isolation of better than 55 dB() and reflectances at each port 55 dB(). 4 Test sample The OFA shall operate at nominal operating conditions. Care shall be taken in maintaining the state of polarization of the input li
36、ght after it is adjusted to the maximum reflectance possible. Changes in the polarization state may result in changes 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 (i.e.,
37、have sufficient attenuation in the direction opposite the signal). This measurement is of little or no value for OFA 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
38、optical gain and consequently on the signal power and pump power. NOTE 3 The line width of the optical source shall not 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 a
39、s important as the magnitude of the reflection. BSI22July2002 Page6 EN6129053:2002 5 Procedure All noise measurements 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 s
40、pecified in the detailed specification (for example, from 10 MHz to 2 GHz in steps of 5 MHz) or (2) at two to five frequencies as specified in the detailed specification. It is assumed that all OFA NF specifications include the “worst-case” scenario (i.e., minimum input signal power, a certain wavel
41、ength, lowest modulation frequency 10 MHz() and linewidth 20 MHz(). In some cases, multiple reflections within 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 reflect
42、ions). To ensure accuracy and repeatability of this procedure, the maximum noise factor contribution from mpi ) , , , ( case worst case worst in max mpi u f u P F , as specified at the “worst-case” frequency and linewidth, shall be translated into the ) , , , ( meas meas in mpi u f u P F that result
43、s from the same “effective” reflective cavity at the low f and meas u of the measurement configuration. Another method of performing this “translation” is to determine the mpi figure of merit mpi I that creates ) , , , ( case worst case worst in max mpi u f u P F . The measurement essentially determ
44、ines the magnitude of the reflectances at input port, output port, or both ports simultaneously, that can generate the specified total noise figure 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 comput
45、ation a) Maximum reflectance tolerable at input and output 1) With a variable optical attenuator (input attenuator), isolator, polarization controller and variable reflector after the optical transmitter, set the input signal power to the OFA, as specified in the relevant detailed specification ( in
46、 P ). Check this power with an optical power meter. 2) Insert OFA (figure 1), a second polarization controller, a second variable reflector, and a second variable attenuator (output attenuator) prior to the receiver. Set variable reflectors initially to 1 R 2 R 55 dB() where R 1and R 2 are the refle
47、ctances. 3) Perform the procedure according to 5.2 of IEC 61290-3-2. From these measurements, the frequency independent contribution to the noise factor ( mpi non F ) and mpi figure of merit ( mpi I ) can be determined. 4) When external reflectances are present, their influence on mpi non F will be
48、negligible compared to the effects on mpi I . Assuming mpi non F is constant, determine the minimum mpi I that could create the “worst-case” noise factor specified at the lowest modulation frequency 10 MHz(), and linewidth 20 MHz(): BSI22July2002 Page7 EN6129053:2002 case worst 2 case worst 2 case worst mpi non case worst mpi 2 ) ( u u f F F I (1) 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
