IEC TR 61292-4:2014

IEC TR 61292-4 ®
Edition 3.0 2014-10
TECHNICAL
REPORT
colour
inside
Optical amplifiers –
Part 4: Maximum permissible optical power for the damage-free and safe use of
optical amplifiers, including Raman amplifiers

61292-4
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IEC TR 61292-4 ®
Edition 3.0 2014-10
TECHNICAL
REPORT
colour
inside
Optical amplifiers –
Part 4: Maximum permissible optical power for the damage-free and safe use of

optical amplifiers, including Raman amplifiers

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
V
ICS 33.160.10 33.180.30 ISBN 978-2-8322-1907-2

– 2 – IEC TR 61292-4:2014 © IEC 2014

CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope and object . 7
2 Normative references . 7
3 Abbreviated terms . 8
4 Maximum transmissible optical power to keep fibres damage-free . 8
4.1 General . 8
4.2 Fibre fuse and its propagation . 9
4.3 Loss-induced heating at connectors or splices . 10
4.4 Connector end-face damage induced by dust/contamination . 11
4.5 Fibre-coat burn/melt induced by tight fibre bending . 13
4.6 Summary of the fibre damage . 14
5 Maximum transmissible optical power to keep eyes and skin safe . 15
5.1 Maximum transmissible exposure (MPE) on the surface of eye and skin . 15
5.2 Maximum permissible optical power in the fibre for the safety of eye and skin. 15
5.2.1 General . 15
5.2.2 Need for APR . 17
5.2.3 Wavelengths . 17
5.2.4 Locations . 17
5.2.5 Nominal ocular hazard distance (NOHD). 17
5.2.6 Power reduction times . 17
5.2.7 Medical aspects of the safety of eyes and skin in existing standards . 18
6 Maximum optical power permissible for optical amplifiers from the viewpoint of
fibre damage as well as eye and skin safety . 19
7 Conclusion . 19
Annex A (informative) General information for optical fibre fuse . 20
A.1 Introduction . 20
A.2 Generating mechanism . 20
A.3 Figure A.3 – Calculated fibre fuse propagation behaviour simulated with the
SiO absorption modelVoid formation mechanism . 23
A.4 Propagation characteristic of a fibre fuse . 24
A.5 Prevention and termination . 26
A.5.1 General . 26
A.5.2 Prevention methods . 26
A.5.3 Termination methods . 26
A.6 Conclusion . 29
Bibliography . 30

Figure 1 – Experimental set-up for fibre fuse propagation . 9
Figure 2 – Connection loss versus temperature increase . 11
Figure 3 – Test set-up . 11
Figure 4 – Surface condition contaminated with metal filings, before the test . 12
Figure 5 – Variation of the power attenuation during the test at several power input
values for plugs contaminated with metal filings . 13
Figure 6 – Polishing surface condition contaminated with metal filing, after the test . 13

Figure 7 – Thermo-viewer image of tightly-bent SMF with optical power of 3 W at
1 480 nm . 14
Figure 8 – Temperature of the coating surface of SMFs against bending with optical
power of 3 W at 1 480 nm . 14
Figure 9 – Maximum permissible power in the fibre against APR power reduction time . 18
Figure A.1 – Front part of the fibre fuse damage generated in the optical fibre . 20
Figure A.2 – SiO absorption model . 22
Figure A.3 – Calculated fibre fuse propagation behaviour simulated with the SiO
absorption modelVoid formation mechanism . 23
Figure A.4 – Series of optical micrographs showing damage generated by 9,0 W
1 480 nm laser light suggesting a mechanism of periodic void formation . 24
Figure A.5 – Images of fibre fuse ignition taken with an ultra-high speed camera and
an optical micrograph of the damaged fibre. 25
Figure A.6 – Power density dependence of the fibre-fuse propagation velocity . 25
Figure A.7 – Optical micrographs showing front part of the fibre fuse damage
generated in SMF-28 fibres with various laser intensities (1 480 nm) . 26
Figure A.8 – Principle of the optical fibre fuse passive termination method and
photograph of the fibre fuse terminator which adopted TEC structure . 27
Figure A.9 – Photograph of hole-assistant fibre and fibre fuse termination using a hole-
assistant fibre . 28
Figure A.10 – Example of fibre fuse active termination scheme . 29
Figure A.11 – Transformation of electric signal by optical fibre fuse . 29

Table 1 – Threshold power of fibre fuse propagation for various fibres . 9
Table 2 – Measurement conditions. 10
Table 3 – Examples of power limits for optical fibre communication systems having
automatic power reduction to reduce emissions to a lower hazard level . 16
Table 4 – Location types within an optical fibre communication system and their
typical installations . 17

– 4 – IEC TR 61292-4:2014 © IEC 2014

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL AMPLIFIERS –
Part 4: Maximum permissible optical power for the damage-free and safe
use of optical amplifiers, including Raman amplifiers

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