BS EN 61300-3-50:2013 Incorporating corrigenda January 2015 and July 2015 BSI Standards Publication Fibre optic interconnecting devices and passive components — Basic test and measurement procedures Part 3-50: Examinations and measurements — Crosstalk for optical spatial switches BS EN 61300-3-50:2013 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 61300-3-50:2013 It is identical to IEC 61300-3-50:2013, incorporating corrigenda January 2015 and July 2015 The start and finish of text introduced or altered by corrigendum is indicated in the text by tags Text altered by IEC corrigendum July 2015 is indicated in the text by The UK participation in its preparation was entrusted by Technical Committee GEL/86, Fibre optics, to Subcommittee GEL/86/2, Fibre optic interconnecting devices and passive components A list of organizations represented on this subcommittee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2015 Published by BSI Standards Limited 2015 ISBN 978 580 91463 ICS 33.180.20 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2013 Amendments/corrigenda issued since publication Date Text affected 28 February 2015 Implementation of IEC corrigendum January 2015 Figure and Figure updated Implementation of IEC corrigendum July 2015 30 September 2015 BS EN 61300-3-50:2013 EN 61300-3-50 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM July 2013 ICS 33.180.20 English version Fibre optic interconnecting devices and passive components Basic test and measurement procedures Part 3-50: Examinations and measurements Crosstalk for optical spatial switches (IEC 61300-3-50:2013) Dispositifs d’interconnexion et composants passifs fibres optiques Procédures fondamentales d’essais et de mesures Partie 3-50: Examens et mesures Diaphonie relative aux commutateurs spatiaux optiques (CEI 61300-3-50:2013) Lichtwellenleiter Verbindungselemente und passive Bauteile Grundlegende Prüf- und Messverfahren Teil 3-50: Untersuchungen und Messungen Übersprechen bei räumlichen Umschaltern für Lichtwellenleiter (IEC 61300-3-50:2013) This European Standard was approved by CENELEC on 2013-06-21 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 national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre 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 language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels © 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 61300-3-50:2013 E BS EN 61300-3-50:2013 EN 61300-3-50:2013 -2- Foreword The text of document 86B/3593/FDIS, future edition of IEC 61300-3-50, prepared by IEC/TC 86B "Fibre optic interconnecting devices and passive components” of IEC/TC 86 “Fibre optics" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61300-3-50:2013 The following dates are fixed: • latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2014-03-21 • latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2016-06-21 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights Endorsement notice The text of the International Standard IEC 61300-3-50:2013 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 indicated: IEC 62074-1 NOTE Harmonised as EN 62074-1 IEC 61300-3-29 NOTE Harmonised as EN 61300-3-29 IEC 60876-1 NOTE Harmonised as EN 60876-1 BS EN 61300-3-50:2013 EN 61300-3-50:2013 -3- Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies Publication Year Title EN/HD Year IEC 61300-1 - Fibre optic interconnecting devices and passive components - Basic test and measurement procedures Part 1: General and guidance EN 61300-1 - IEC 61300-3-2 - Fibre optic interconnecting devices and EN 61300-3-2 passive components - Basic test and measurement procedures Part 3-2: Examinations and measurements Polarization dependent loss in a single-mode fibre optic device - –4– BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 CONTENTS Scope Normative references General description Apparatus 4.1 Light source S 4.2 Temporary joint TJ 4.3 Terminations T 4.4 Detector D Measurement procedure 5.1 General 5.2 Test set-up 5.3 Measurement of P 5.4 Measurement of P 5.5 Measurement of P i (i=3 to N) 5.6 Measurement for other input ports Calculation 6.1 Calculation of crosstalk for specified port pairs 6.2 Calculation of total crosstalk for a specified output port 10 6.3 Crosstalk of M x N fibre optic switch 10 6.4 Total crosstalk of M x N fibre optic switch 10 Details to be specified 10 7.1 Light source 10 7.2 Temporary joint 11 7.3 Terminations 11 7.4 Detector 11 7.5 DUT 11 7.6 Others 11 Bibliography 12 Figure – Crosstalk for N x optical switch Figure – Measurement set-up of crosstalk for x N optical switch Figure – Measurement setup of P Figure – Measurement set-up of P BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 –5– FIBRE OPTIC INTERCONNECTING DEVICES AND PASSIVE COMPONENTS – BASIC TEST AND MEASUREMENT PROCEDURES – Part 3-50: Examinations and measurements – Crosstalk for optical spatial switches Scope This part of IEC 61300 describes the procedure to measure the crosstalk of optical signals between the ports of a multiport M x N (M input ports and N output ports) fibre optic spatial switch The crosstalk is defined as the ratio of the optical power at an output port which comes from the unconnected input port, to the optical power at the output port which comes from the connected input port Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies IEC 61300-1, Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 1: General and guidance IEC 61300-3-2, Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 3-2: Examinations and measurements – Polarization dependent loss in a single-mode fibre optic device General description The general meaning of crosstalk is the ratio of an undesired signal power to a desired signal power The crosstalk of N x (N input ports and one output port) fibre optic spatial switches is shown in Figure For an N x M (N input ports and M output ports) fibre optic switch, the crosstalk is the same as that for an N x optical switch but expanded across M output ports A fibre optic switch is basically bidirectional, i.e a x N (1 input port and N output ports) optical switches can operate as an N x (N input ports and output port) switch The crosstalk for an N x optical switch is measured as a x N optical switch, as shown in Figure When the input port for a x N optical switch is connected to a light source, the crosstalk for a transmitting output port versus an isolated output port is the ratio of output power of these two output ports, expressed in decibels Crosstalk is a negative value in dB Do not use “isolation” in place of “crosstalk” as the two have a different values and meanings The meaning of isolation is the optical loss for a port pair intended to block transmission, i.e for which loss is nominally infinite Isolation is a positive value in dB Crosstalk is a negative value in dB NOTE For WDM devices, crosstalk is defined as the value of the ratio between the optical power of the specified signal and all noise, as defined in IEC 62074-1 [1] The crosstalk for WDM devices is generally used as _ Numbers in square brackets refer to the Bibliography BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 –6– not simply “crosstalk”, but “some prefix” crosstalk, such as adjacent channel crosstalk, total crosstalk and so on The measurement method of crosstalk for DWDM devices are described in IEC 61300-3-29 [2] Port (signal 1) Common port (signal 1, and the sum of signals (2 ~ n) as noise) Port (signal 2) Port n (signal n) N × optical switch IEC 959/13 Figure – Crosstalk for N x optical switch Port (transmitting port) Light source Optical detector Port (isolated port) Port n (isolated port) Optical detector n × N optical switch IEC 960/13 Figure – Measurement set-up of crosstalk for x N optical switch For single mode fibre optic switches, the crosstalk may depend on the polarization state of the input light A polarization state change system (PSCS; a polarization controller or a polarization scrambler) should be used with a light source In this case, the crosstalk is generally defined as the maximum value of the measured crosstalk for all polarization states of the input light For multi-mode fibre optic switches, the launch mode of input light shall be in accordance with IEC 61300-1 Since, in practice the crosstalk levels of fibre optic switches can be very small, (of the order of under –70 dB), the measurement can be degraded by several factors Therefore, this procedure is designed to either circumvent these factors, or to point them out so that adequate care can be taken and the right choice of test apparatus made Factors which can degrade a measurement of crosstalk include: – the coupling of ambient light into measurement channels; – the reflection of light from the ends of fibre pigtails; – the light carried in cladding modes; – the uncertainty of the power meter at low light levels; – the fibre pigtail lengths since light can scatter (Rayleigh scattering) along the pigtails Apparatus 4.1 Light source S The light source is pigtailed or connected to a launch optical fibre compatible with the input port of the device under test (DUT) It is also designed and conditioned to achieve the required launch conditions as stated in IEC 61300-1 For measurements of DUTs which are not inherently broadband in optical performance, the spectral output of the light source shall be characterized not only in the vicinity of the operating wavelength range by means of full BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 –7– width at half maximum (FWHM) but also in the region of the spectral tail This requirement can be specified as "power less than X dB below peak at wavelengths Y nm from peak output" and can be achieved by use of in-line bandpass filters The output power of the light source shall also be sufficiently high to permit a large measurement dynamic range with the optical detector used The output power stability shall be less than or equal to 0,05 dB per hour The dynamic range of the source/detector combination shall be at least 10 dB greater than the absolute value of the minimum crosstalk to be measured For the measurement of single mode fibre optic switches, the polarization dependency of crosstalk shall be considered A polarization controller is used to measure the polarization dependency of crosstalk The detail requirement of a PSCS is described in IEC 61300-3-2 The launch condition, power stability and dynamic range shall satisfy the requirement as mentioned above for the output power of a PSCS when a PSCS is used 4.2 Temporary joint TJ This is a method, device or mechanical fixture for temporarily aligning two fibre ends into a reproducible, low loss joint and polarization independent splicing Typically, a fusion splice is used since mechanical splices may exhibit some polarization sensitivity if the endfaces are not perpendicular to the fibre axis The stability of the temporary joint shall be compatible with the required measurement precision 4.3 Terminations T These terminations are components or techniques to suppress reflected light from the DUT output ports Three types of terminations are suggested: – angled fibre ends; – the application of an index matching material to the fibre end; – attenuation of the fibre, for example with a mandrel wrap The fibre termination shall have a return loss of at least 10 dB greater than the absolute value of the minimum crosstalk to be measured 4.4 Detector D A high dynamic range optical power meter should be used for the detector Its wavelength range shall be wider than the operating wavelength range of the DUT The linearity of sensitivity of the detector shall be small enough to minimize the measurement uncertainty The detector shall have a sufficiently large detection area and be placed sufficiently close to the output to capture all of the light emitting from the output fibre of the DUT to be measured 5.1 Measurement procedure General This clause describes the measurement procedure of crosstalk for M x N (M input ports and N output ports) fibre optic switches 5.2 Test set-up Figure shows the test set-up for crosstalk measurement The light source is connected to the selected input port (I1) of the DUT by means of a TJ where appropriate or by means of a connector in the case of a DUT fitted with a connector The detector is connected to a transmitting output port of the DUT (port O1) which is to be measured for crosstalk against another chosen output port nominally isolated from the previous one (port O2) All other ports of the DUT are terminated (T) Les corrections la version franỗaise sont donnộes aprốs le texte anglais Figure – Measurement setup of P BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 –8– Replace existing Figure with the new following Figure PPinin S S TJTJ Port I1I1 Port Port O1O1 Port DUT DD P1P1 Port O2O2 Port DUT T T T T TT M M Inputs inputs TT NNoutputs Outputs IEC IEC 61350-3-50:2013-05/COR1:2015-01(en-fr) IEC 961/13 Figure – Measurement setup of P1 Figure – Measurement setup of P FigureMeasurement – Measurement 5.3 of P setup of P Turn on existing the light Figure source4 Swith andthe allow for4 it to stabilize Switch the fibre optic Replace new sufficient following time Figure spatial switch DUT to connect between the selected input port and the transmitting output port (port O1) Measure and record P (dBm) When a PSCS is used with a light source for measuring single mode fibre optic spatial switches, change the polarization states of the input light in accordance with IEC 61300-3-2 Both the “all polarization state” method and Mueller matrix method may be used P in Figure changes depending on the state of polarization, from P 1min to P 1max Use P 1max as P1 5.4 Measurement of P Move the detector D to port O2 which is the nominally isolated port for the selected input port as shown in Figure Terminate port O1, ensuring that this port is still linked to the input port of the DUT For the fibre optic switch DUT, this means ensure it is connected to port O1 Measure and record the output power from port O2 as P2 (dBm) When a PSCS is used with a light source for measuring single mode fibre optic spatial switches, change the polarization states of the input light in accordance with IEC 61300-3-2 Both the “all polarization state” method and Mueller matrix method may be used P in Figure changes depending on the state of polarization, from P 2min to P 2max Use P 2min as P2 BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 –9– –2– Pin S S Pin TJ TJ Port I1 I1 Port Port O1O1 Port DUT DUT T T IEC 61350-3-50:2013/COR1:2015 IEC 2015 T D T T T Port O2O2 Port T Inputs MMInputs N Outputs N Outputs D P2 P2 T IEC Figure – Measurement setup of P2 IEC 962/13 Figure – Measurement set-up of P Measurement of P i (i=3 to N) 5.5 Repeat the procedure of 5.4 for the output port O1, to measure P i (dBm) and record, i = to N 5.6 Measurement for other input ports Change the connection of light source S to another input port Ij (j = to M) Repeat the procedure of 5.2 to 5.5 Calculation 6.1 Calculation of crosstalk for specified port pairs The crosstalk (XT 12 ) for the pairs for port O1 to port I1 and port O2 to port I1 is given by Equation (1): XT 12 = P – P (dB) (1) This crosstalk is the crosstalk of signal light with signal light as noise for signal light for output port O1, when this DUT is used for M x N (M input ports and N output ports), connected port I1 to port O1 and input signal light from port O1, signal light from port O2. For single mode fibre optic spatial switches, the polarization dependency of crosstalk shall be considered In this case, the crosstalk (XT) is calculated by using Equation (2): XT 12 = IL max,11 – IL min,12 (2) where IL min,12 is the minimum insertion loss for input port to output port 2; IL max,11 is the maximum insertion loss for input port to output port when input port is connected to output port The minimum and maximum insertion loss is calculated from the average insertion loss (IL ave ) and PDL as Equations (3) and (4): BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 – 10 – IL = IL ave – PDL/2 (3) IL max = IL ave + PDL/2 (4) P shall be the maximum value of the power for all polarization states of input light, and P shall be the minimum value of the power for all polarization states of input light 6.2 Calculation of total crosstalk for a specified output port The total crosstalk is the ratio of the total noise (total power of leakage from unconnected ports) to the desired signal power from the connected port The total crosstalk XT tot (O1) of the output port of port O1, in case of connecting port I1 and port O1, for the M x N fibre optic switch of this DUT is given by Equation (5), which is the expansion of Equation (1): i =N Pi XT (O ) = 10 log 10 10 tot 10 i =2 ∑ − P1 (5) where P i is given in 5.5. For single mode fibre optic spatial switches, the total crosstalk XT tot (O1) of the output port of port O1, in the case of connecting port I1 and port O1, for the M x N fibre optic switch is calculated by using Equation (6), which is the expansion of Equation (2): i = N − IL min,1i 10 XTtot (O1 ) = ILmax,11 + 10 log10 10 i =2 ∑ (6) where IL min,1i is the minimum insertion loss for input port to output port I when input port is connected to output port In the case where an N x spatial optical switch is used for selecting a port from N input ports (see Figure 1), all of the optical power from unconnected input ports is noise For system suppliers, total crosstalk is necessary to estimate the influence on transmission performance, especially OSNR 6.3 Crosstalk of M x N fibre optic switch The crosstalk of an M x N fibre optic switch is defined as the maximum crosstalk for all combination of port pairs, calculated using Equation (1) 6.4 Total crosstalk of M x N fibre optic switch The total crosstalk of an M x N fibre optic switch is defined as the maximum total crosstalk for all output ports and all switching connecting port pairs, calculated using Equation (6) Details to be specified The following details, as applicable, shall be specified in the relevant specification and/or recorded in the measurement report: 7.1 Light source – Type of light source – Centre wavelength BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 – 11 – – Spectral width – Output power – Power stability during measurement – Type of PSCS and measurement method of polarization dependency (when used) – Type of mode filter and launch condition (when used) 7.2 Temporary joint – Type of temporary joint – Return loss of temporary joint – Insertion loss of temporary joint 7.3 Terminations – Type of terminations – Return loss of terminations 7.4 Detector – Type of detector – Dynamic range of sensitivity – Linearity of sensitivity – Polarization dependency of sensitivity 7.5 DUT – Input/output port combinations of the DUT to be measured – Performance requirements for crosstalk for each specified port (input/output/isolated) combination 7.6 – Others Deviations from this test procedure – 12 – BS EN 61300-3-50:2013 61300-3-50 © IEC:2013 Bibliography [1] IEC 62074-1, Fibre optic interconnecting devices and passive components – Fibre optic WDM devices – Part 1: Generic specification [2] IEC 61300-3-29, Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 3-29: Examinations and measurements – Measurement techniques for characterizing the amplitude of the spectral transfer function of DWDM components Additional non-cited references IEC 60876-1, Fibre optic interconnecting devices and passive components – Fibre optic spatial switches – Part 1: Generic specification _ _ A second edition of IEC 61300-3-29 is due to be published shortly This page deliberately left blank NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British 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