1、BRITISH STANDARD BS EN 61290-11-2: 2005 Optical amplifiers Test methods Part 11-2: Polarization mode dispersion parameter Poincar sphere analysis method The European Standard EN 61290-11-2:2005 has the status of a British Standard ICS 33.180.30 BS EN 61290-11-2:2005 This British Standard was publish
2、ed under the authority of the Standards Policy and Strategy Committee on 19 August 2005 BSI 19 August 2005 ISBN 0 580 46049 5 National foreword This British Standard is the official English language version of EN 61290-11-2:2005. It is identical with IEC 61290-11-2:2005. The UK participation in its
3、preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/3, Fibre optic systems and active devices, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British
4、 Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online
5、. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible
6、 international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, th
7、e EN title page, pages 2 to 14, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 61290-11-2 NORME EUROPENNE EUROPISCHE NORM May 2005 C
8、ENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels ICS 33.180.30 English version Optical amplifiers Test methods Part 11-2: Polariza
9、tion mode dispersion parameter Poincar sphere analysis method (IEC 61290-11-2:2005) Amplificateurs optiques Mthodes dessai Partie 11-2: Paramtre de dispersion en mode de polarisation Mthode danalyse par la sphre de Poincar (CEI 61290-11-2:2005) Prfverfahren fr Lichtwellenleiter- Verstrker Teil 11-2:
10、 Polarisationsmodendispersion - Kugelanalyse nach Poincar (IEC 61290-11-2:2005) This European Standard was approved by CENELEC on 2005-04-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a
11、 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
12、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, Cyprus, Czech Repub
13、lic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. 2005 CENELEC - All rights of exploitation in any form and by any
14、means reserved worldwide for CENELEC members. Ref. No. EN 61290-11-2:2005 E - 2 - Foreword The text of document 86C/640/FDIS, future edition 1 of IEC 61290-11-2, 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
15、 was approved by CENELEC as EN 61290-11-2 on 2005-04-01. 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 (dop) 2006-01-01 latest date by which the national standards conflicting wit
16、h the EN have to be withdrawn (dow) 2008-04-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61290-11-2:2005 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes h
17、ave to be added for the standards indicated: IEC 60793-1-1 NOTE Harmonized as EN 60793-1-1:2003 (not modified). IEC 60825-1 NOTE Harmonized as EN 60825-1:1994 (not modified). IEC 60825-2 NOTE Harmonized as EN 60825-2:2004 (not modified). IEC 60874-1 NOTE Harmonized as EN 60874-1:1999 (not modified).
18、 IEC 61291-1 NOTE Harmonized as EN 61291-1:1998 (not modified). IEC 61291-4 NOTE Harmonized as EN 61291-4:2003 (not modified). _ EN 61290-11-2:2005 3 EN 61290-11-2:2005 CONTENTS 1 Scope and object. 5 2 Normative references. 5 3 Abbreviated terms 6 4 Apparatus . 6 4.1 General 6 4.2 Light source 7 4.3
19、 State of polarization generator 8 4.4 Analyser. 9 5 Procedure 10 6 Calculations .11 6.1 Poincar sphere analysis calculations 11 6.2 Display of differential group delay versus wavelength.12 6.3 Average differential group delay.12 6.4 Maximum differential group delay.12 7 Test results 12 Annex ZA (no
20、rmative) Normative references to international publications with their corresponding European publications13 Bibliography.14 blank 5 EN 61290-11-2:2005 OPTICAL AMPLIFIERS TEST METHODS Part 11-2: Polarization mode dispersion parameter Poincar sphere analysis method 1 Scope and object This part of IEC
21、 61290 applies to all commercially available optical amplifiers (OAs) including optical fibre amplifiers (OFAs) using active fibres and semiconductor optical amplifiers (SOAs) using semiconductor gain media. Polarization mode dispersion (PMD) causes an optical pulse to spread in the time domain. Thi
22、s dispersion could impair the performance of a telecommunications system. The effect can be related to differential group velocity and corresponding arrival times of different polarization components of the signal. For a narrowband source, the effect can be related to a differential group delay (DGD
23、) between pairs of orthogonally polarized principal states of polarization (PSP). This test method describes a procedure for measuring the PMD of OAs. The measurement result is obtained from the measurement of the normalised Stokes parameters at two closely spaced wavelengths. The mathematical basis
24、 together with an example of calculation for the Poincar sphere analysis (PSA) method to calculate PMD is provided in the technical report IEC 61292-5. The method described herein has been shown to be immune to polarization-dependent gain (PDG) and polarization-dependent loss (PDL) up to approximate
25、ly 1 dB . Although the PSA, in practice, is applicable to unpumped (that is, unpowered) OAs, the PSA technique in this standard applies to pumped (that is, powered) OAs only. NOTE All numerical values followed by () are suggested values for which the measurement is assured. Other values may be accep
26、table but should be verified. 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 (including any amendments) appli
27、es. IEC 61292-5, Optical amplifiers Part 5: Polarization mode dispersion parameter General information EN 61290-11-2:2005 6 3 Abbreviated terms ASE amplified spontaneous emission DGD differential group delay DOP degree of polarization DUT device (optical amplifier) under test FTSA Fourier transform
28、spectrum analyser JME Jones matrix eigenanalysis method OA optical amplifier OFA optical fibre amplifier OSA optical spectrum analyser PDG polarization-dependent gain PDL polarization-dependent loss PDV polarization dispersion vector PMD polarization mode dispersion POWA planar optical waveguide amp
29、lifier PSA Poincar sphere analysis PSP principal state of polarization RBW resolution bandwidth RMS root mean square SOA semiconductor optical amplifier SOP state of polarization 4 Apparatus 4.1 General The test method described herein requires a polarized signal at the input of the polarimeter. Alt
30、hough the test source is highly polarized, the degree of polarization (DOP) at the output of the OA can be significantly reduced by the amplified spontaneous emission (ASE). The source DOP should be at least 25 % within the optical bandwidth of the state of polarization (SOP) measurement. This is of
31、 particular concern when using a tuneable narrowband source without a tracking optical band-pass filter at the amplifier output, because the total ASE power out of the amplifier, i.e. the ASE spectrum integrated over all wavelengths, impinges on the photodetectors whatever the selected wavelength. I
32、n this case, proper saturation conditions must be ensured in order for the DOP to be high enough for accurate measurement (see IEC 61292-5). The source DOP requirement is less of a concern when using a broadband source and spectral analysis (which acts as a narrowband filter centred about the select
33、ed wavelength), or a tuneable narrowband source with a tracking narrowband band-pass filter at the output of the amplifier. In this case the ASE power, within the resolution bandwidth (RBW) of the spectral analysis, or output-filter bandwidth, remains low with respect to signal power for a broader r
34、ange of saturation conditions. 7 EN 61290-11-2:2005 See Figure 1 for a schematic diagram of the key components in a typical measurement system. Figure 1 Schematic diagram of equipment (typical) 4.2 Light source In all cases a polarized wavelength-range light source shall be used. The wavelength rang
35、e shall at least cover the OA gain spectrum. Two kinds of light source may be used depending on the type of analyser used. For instance, a narrowband source can be used with a polarimetric broadband analyser while a broadband source can be used with a narrow band-pass wavelength filtering analyser.
36、4.2.1 Narrowband source The narrowband source shall be tuneable across the intended measurement wavelength range. The spectral distribution of the source shall be narrow enough so that light emerging from the DUT remains polarized under all conditions of the measurement. However, in all cases, the s
37、ource linewidth and the wavelength step shall be carefully selected in order to respect the Nyquist sampling theorem. In cases where reflections causing multiple path interference cannot be avoided, the source linewidth must not be too narrow in order to avoid coherence interference effects. Passive
38、 and active coherence control techniques are available. See IEC 61292-5 for more details on multiple path interferences and coherence interference effects. Polarization dispersion matrix ) ( 2 1W tr W = where 1 = T d dTW Eigenvalues of T(+ )T -1 () Argument formula Link ) ( i = r 2where is the Pauli
39、 operator PSA JMEDGD Polarization dispersion Vector r Arcsine formula Modulus of r SOP generator s in () Analyser of the measured normalised Stokes vectors s out () PSA JME Wavelength-range light source DUT IEC 366/05 EN 61290-11-2:2005 8 4.2.2 Broadband source The source can be an ASE source whose
40、spectral distribution matches the DUT one. In all cases, the filtering analyser effective linewidth (RBW) and the wavelength step shall be carefully selected in order to respect the Nyquist sampling theorem. Figure 2 provides an example of an experimental implementation using a broadband source, suc
41、h as an ASE source. Stokes vectors Michelson interferometer HeNe DUT PSA analysisASE source SOP generator Polarimeter IEC 367/05 Figure 2 Experimental implementation of the PSA method with ASE source 4.3 State of polarization generator A SOP generator is used for generating the input Stokes vectors
42、s in (). The SOP generator is composed of a polarization adjuster, a set of linear polarizers and suitable optics. Figure 3 illustrates a possible SOP generator. SOP output 0 Linear polarizers Source input Polarization adjuster 45 90 IEC 368/05 Figure 3 Example of SOP generator 9 EN 61290-11-2:2005
43、4.3.1 Polarization adjuster and linear polarizers If the source is polarized, the polarization adjuster follows the light source and is set to provide roughly circularly polarized light to the polarizers, so that the polarizers never cross polarization with the input light. If the source is unpolari
44、zed, this is not necessary. For the polarized source, adjust the polarization as follows. Make sure that the light source wavelength range is set to the centre of the range to be measured. Insert each of the three polarizers into the beam and perform three corresponding power measurements at the out
45、put of the polarizer. Adjust the source polarization via the polarization adjuster such that the three powers fall within approximately a 3-dB range of one another. In an open beam version of the set-up, a waveplate may perform the polarization adjustment. In addition to the polarization adjuster, t
46、hree linear polarizers are arranged for insertion into the light beam in turn. Their actual relative angles do not need to be known but need to be distinct from each other. However they should provide sufficient sampling of the three such oriented components for accurate determination of these compo
47、nents. 4.3.2 Input optics An optical lens system or single-mode fibre pigtail may be employed to excite the DUT. If pigtails are used, interference effects due to reflections should be avoided. This may require index matching materials. The pigtails shall be single-mode. If an optical lens system is
48、 used, some suitable means, such as a vacuum chuck, shall be used to provide a highly stable support to the input end of the DUT. 4.4 Analyser Two kinds of analysers may be used depending on the type of source used. For instance, a polarimetric broadband analyser can be used with a narrowband source
49、 while a narrow band- pass wavelength filtering analyser can be used with a broadband source. The narrow band- pass wavelength filtering analyser may be: an optical filter, an optical spectrum analyser (OSA), or an interferometer used as a Fourier transform spectrum analyser (FTSA). The equivalent optical filtering shall be narrow enough so that light emerging from the DU
