1、 IEC/TR 61282-11 Edition 1.0 2012-05 TECHNICAL REPORT Fibre optic communication system design guides Part 11:Multimode launch conditions IEC/TR 61282-11:2012(E)Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,downloaded on Nov-28-2014 by James Madison.No further reproduct
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9、ct the Customer Service Centre:csciec.ch.Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,downloaded on Nov-28-2014 by James Madison.No further reproduction or distribution is permitted.Uncontrolled when printed.IEC/TR 61282-11 Edition 1.0 2012-05 TECHNICAL REPORT Fibre o
10、ptic communication system design guides Part 11:Multimode launch conditions INTERNATIONAL ELECTROTECHNICAL COMMISSION V ICS 33.180.01 PRICE CODE ISBN 978-2-88912-078-9 Registered trademark of the International Electrotechnical Commission Warning!Make sure that you obtained this publication from an a
11、uthorized distributor.Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,downloaded on Nov-28-2014 by James Madison.No further reproduction or distribution is permitted.Uncontrolled when printed.2 TR 61282-11 IEC:2012(E)CONTENTS FOREWORD.4 INTRODUCTION.6 1 Scope.7 2 Normati
12、ve references.7 3 Terms and definitions.7 4 Background.8 5 Metrics for multimode launch conditions.8 General.8 5.1 Coupled power ratio(CPR).9 5.2 Mode power distribution/relative power distribution(MPD/RPD).9 5.3 Encircled flux(EF).10 5.46 Uncertainties.10 General.10 6.1 Measurement model and uncert
13、ainties.10 6.2 Uncertainty due to the setup.11 6.3 Uncertainty due to the power meter.11 6.4 Random uncertainties.11 6.5 Uncertainty due to fibre manipulation.11 6.5.1 Uncertainties due to launch conditions.12 6.5.2 Example of uncertainty accumulation.13 6.67 Encircled flux envelope theory and assum
14、ptions.14 Mode field eigenfunctions.14 7.1 Connections,attenuation and the encircled flux template.16 7.2 Target weights.17 7.3 Coupling matrix calculations.20 7.48 Wavelength bias correction to EF targets/limits with spectrally broad sources.21 General.21 8.1 Modified spectrum assumptions.21 8.2 De
15、termining the EF targets.22 8.3 Determining the EF limits.23 8.4 Validating the EF limits.24 8.5Annex A(informative)IEC international standards related to multimode launch conditions.26 Annex B(informative)Coupled power ratio measurement for fibre-optic sources.28 Annex C(informative)Limits on RPD a
16、nd MPD.30 Bibliography.35 Figure 1 Uncertainties due to the launch conditions for a given loss.13 Figure 2 Comparison of target weights.18 Figure 3 Incremental loss using OFL launch.19 Figure 4 Incremental loss using target launch.20 Figure C.1 Example of a characteristic MTF.31 Figure C.2 Relative power distribution(RPD)specification.33 Figure C.3 Example of a characteristic MPD.33 Copyrighted material licensed to BR Demo by Thomson Reuters(Scientific),Inc.,downloaded on Nov-28-2014 by Jame