SIST EN IEC 61290-4-3:2018

SLOVENSKI STANDARD
oSIST prEN 61290-4-3:2017
01-september-2017
2SWLþQLRMDþHYDOQLNL3UHVNXVQHPHWRGHGHO(OHNWULþQLSDUDPHWULRMDþHQMD
(QRNDQDOQLRSWLþQLRMDþHYDOQLNL]DL]KRGQRNUPLOMHQMHPRþL
Optical amplifiers - Test methods - Part 4-3: Power transient parameters - Single channel
optical amplifiers in output power control
Optische Verstärker - Prüfverfahren - Teil 4-3: Leistungs-Transientenkenngrößen von Ein
-Kanal-LWL-Verstärkern mit Ausgangs-Leistungskontrolle
Amplificateurs optiques - Méthodes d'essai - Partie 4-3: Paramètres de puissance
transitoire - Contrôle de la puissance de sortie des amplificateurs optiques monocanaux
Ta slovenski standard je istoveten z: prEN 61290-4-3:2017
ICS:
33.180.30 2SWLþQLRMDþHYDOQLNL Optic amplifiers
oSIST prEN 61290-4-3:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 61290-4-3:2017

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oSIST prEN 61290-4-3:2017
86C/1462/CDV

COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61290-4-3 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2017-07-07 2017-09-29
SUPERSEDES DOCUMENTS:
86C/1456/RR

IEC SC 86C : FIBRE OPTIC SYSTEMS AND ACTIVE DEVICES
SECRETARIAT: SECRETARY:
United States of America Mr Jack Dupre
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:


Other TC/SCs are requested to indicate their
interest, if any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY SAFETY
ASSURANCE

SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members
of CENELEC, is drawn to the fact that this
Committee Draft for Vote (CDV) is submitted for
parallel voting.
The CENELEC members are invited to vote through
the CENELEC online voting system.

This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent
rights of which they are aware and to provide supporting documentation.

TITLE:
Optical amplifiers - Test methods - Part 4-3: Power transient parameters - Single channel
optical amplifiers in output power control

NOTE FROM TC/SC OFFICERS:


Copyright © 2017 International Electrotechnical Commission, IEC. All rights reserved. It is permitted to download this
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
C/
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
permission in writing from IEC.

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oSIST prEN 61290-4-3:2017
IEC CDV 61290-4-3/Ed2 © IEC 2017 – 2 – 86C/1462/CDV
1 CONTENTS
2 CONTENTS . 2
3 FOREWORD . 3
4 1 Scope . 5
5 2 Normative references . 5
6 3 Terms, definitions and abbreviations . 5
7 3.1 Terms and definitions . 5
8 3.2 Abbreviations . 7
9 4 Apparatus . 8
10 4.1 Test set-up . 8
11 4.2 Characteristics of test equipment . 8
12 5 Test sample . 9
13 6 Procedure . 9
14 6.1 Test preparation. 9
15 6.2 Test conditions . 9
16 7 Calculations . 10
17 8 Test results . 11
18 8.1 Test settings . 11
19 8.2 Test data . 12
20 Annex A (informative) Overview of power transient events in single channel EDFA . 13
21 A.1 Background. 13
22 A.2 Characteristic input power behaviour . 13
23 A.3 Parameters for characterizing transient behaviour . 16
24 Annex B (informative) Background on power transient phenomena in a single channel
25 EDFA . 18
26 B.1 Amplifier chains in optical networks . 18
27 B.2 Typical optical amplifier design . 18
28 B.3 Approaches to address detection errors . 20
29 Annex C (informative) Slew rate effect on transient gain response . 24
30 Bibliography . 25
31
32 Figure 1 – Power transient test set-up. 8
33 Figure 2 – OA output power transient response of a) input power increase . 11
34 Figure A.1 – Example OA input power transient cases for a receiver application . 14
35 Figure A.2 – Input power measurement parameters . 15
36 Figure A.3 – OA output power transient response . 17
37 Figure B.1 – Transient response to input power drop . 22
38 Figure B.2 – Transient response to input power rise . 23
39
40 Table 1 – Examples of transient control measurement test conditions . 10
41

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42 INTERNATIONAL ELECTROTECHNICAL COMMISSION
43 ____________
44
45 OPTICAL AMPLIFIERS – TEST METHODS
46
47 Part 4-3: Power transient parameters –
48 Single channel optical amplifiers in output power control
49
50 FOREWORD
51 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
52 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
53 international co-operation on all questions concerning standardization in the electrical and electronic fields. To
54 this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
55 Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
56 Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
57 in the subject dealt with may participate in this preparatory work. International, governmental and non-
58 governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
59 with the International Organization for Standardization (ISO) in accordance with conditions determined by
60 agreement between the two organizations.
61 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
62 consensus of opinion on the relevant subjects since each technical committee has representation from all
63 interested IEC National Committees.
64 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
65 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
66 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
67 misinterpretation by any end user.
68 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
69 transparently to the maximum extent possible in their national and regional publications. Any divergence
70 between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
71 the latter.
72 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
73 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
74 services carried out by independent certification bodies.
75 6) All users should ensure that they have the latest edition of this publication.
76 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
77 members of its technical committees and IEC National Committees for any personal injury, property damage or
78 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
79 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
80 Publications.
81 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
82 indispensable for the correct application of this publication.
83 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
84 patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
85 International Standard IEC 61290-4-3 has been prepared by subcommittee 86C: Fibre optic
86 systems and active devices, of IEC technical committee 86: Fibre optics.
87 This second edition cancels and replaces the first edition published in 2015. It is a technical
88 revision that aligns the measure of amplified spontaneous emission (ASE) relative to signal
89 power with the definition in IEC 61290-3-3.
90 This International Standard is to be used in conjunction with IEC 61291-1, on which it is
91 based.
92 The text of this standard is based on the following documents:
FDIS Report on voting
86C/xxxx/FDIS 86C/xxxx/RVD

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93
94 Full information on the voting for the approval of this standard can be found in the report on
95 voting indicated in the above table.
96 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
97 A list of all parts of the IEC 61290 series, published under the general title Optical amplifiers –
1)
98 Test methods can be found on the IEC website.
99 The committee has decided that the contents of this publication will remain unchanged until
100 the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
101 related to the specific publication. At this date, the publication will be
102 • reconfirmed,
103 • withdrawn,
104 • replaced by a revised edition, or
105 • amended.
106 The National Committees are requested to note that for this document the stability date
107 is 2022.
108 THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND WILL BE
109 DELETED AT THE PUBLICATION STAGE.
110
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
111
112
___________
1)
The first editions of some of these parts were published under the general title Optical fibre amplifiers – Basic
specification or Optical amplifier test methods.

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113 OPTICAL AMPLIFIERS – TEST METHODS
114
115 Part 4-3: Power transient parameters –
116 Single channel optical amplifiers in output power control
117
118 1 Scope
119 This part of IEC 61290 applies to output power controlled optically amplified, elementary sub-
120 systems. It applies to optical fibre amplifiers (OFA) using active fibres containing rare-earth
121 dopants, presently commercially available, as indicated in IEC 61291-1, as well as alternative
122 optical amplifiers that can be used for single channel output power controlled operation, such
123 as semiconductor optical amplifiers (SOA).
124 The object of this standard is to provide the general background for optical amplifier (OA)
125 power transients and its measurements and to indicate those IEC standard test methods for
126 accurate and reliable measurements of the following transient parameters:
127 a) Transient power response
128 b) Transient power overcompensation response
129 c) Steady-state power offset
130 d) Transient power response time
131 The stimulus and responses behaviours under consideration include:
132 1) Channel power increase (step transient)
133 2) Channel power reduction (inverse step transient)
134 3) Channel power increase/reduction (pulse transient)
135 4) Channel power reduction/increase (inverse pulse transient)
136 5) Channel power increase/reduction/increase (lightning bolt transient)
137 6) Channel power reduction/increase/reduction (inverse lightning bolt transient)
138 These parameters have been included to provide a complete description of the transient
139 behaviour of an output power transient controlled OA. The test definition defined here are
140 applicable if the amplifier is an OFA or an alternative OA. However, the description in
141 Annex A of this document concentrates on the physical performance of an OFA and provides
142 a detailed description of the behaviour of OFA; it does not give a similar description of other
143 OA types.
144 2 Normative references
145 The following documents, in whole or in part, are normatively referenced in this document and
146 are indispensable for its application. For dated references, only the edition cited applies. For
147 undated references, the latest edition of the referenced document (including any
148 amendments) applies.
149 IEC 61291-1, Optical amplifiers – Part 1: Generic specification
150 3 Terms, definitions and abbreviations
151 3.1 Terms and definitions
152 For the purposes of this document, the following terms and definitions apply.

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153 ISO and IEC maintain terminological databases for use in standardization at the following
154 addresses:
155 • IEC Electropedia: available at http://www.electropedia.org/
156 • ISO Online browsing platform: available at http://www.iso.org/obp
157 3.1.1
158 input signal
159 optical signal that is input to the OA
160 3.1.2
161 input power excursion
162 relative input power difference before, during and after the input power stimulus event that
163 causes an OA transient power excursion.
164 Note 1 to entry: Input power excursion is expressed in dB.
165 3.1.3
166 input power rise time
167 time it takes for the input optical signal to rise from 10 % to 90 % of the total difference
168 between the initial and final signal levels during an increasing power excursion event
169 Note 1 to entry: See Figure A.2
170 3.1.4
171 input power fall time
172 time it takes for the input optical signal to fall from 10 % to 90 % of the total difference
173 between the initial and final signal levels during a decreasing power excursion event
174 Note 1 to entry: See Figure A.2
175 3.1.5
176 slew rate
177 maximum rate of change of the input optical signal during a power excursion event
178 3.1.6
179 transient power response
180 maximum or minimum deviation (overshoot or undershoot) between the OA’s target power
181 and the observed power excursion induced by a change in an input channel power excursion
182 Note 1 to entry: Once the output power of an amplified channel deviates from its target power, the control
183 electronics in the OA should attempt to compensate for the power difference or transient power response, bringing
184 the OA output power back to its original target level.
185 Note 2 to entry: Transient power response is expressed in dB.
186 3.1.7
187 transient power settling time
188 amount of time taken to restore the power of the OA to a stable power level close to the target
189 power level
190 Note 1 to entry: This parameter is measured from the time when stimulus event that created the power fluctuation
191 to the time at which the OA power response is stable and within specification.
192 3.1.8
193 transient power overcompensation response
194 maximum deviation between the amplifier’s target output power and the power resulting from
195 the control electronics’ instability
196 Note 1 to entry: Transient power overcompensation response occurs after a power excursion, when an amplifier’s
197 control electronics attempts to bring the power back to the amplifier’s target level. The control process is iterative,

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198 and control electronics may initially overcompensate for the power excursion until subsequently reaching the
199 desired target power level.
200 Note 2 to entry: The transient power overcompensation response parameter is generally of lesser magnitude than
201 the transient power response and has the opposite sign.
202 Note 3 to entry: Transient power overcompensation response is expressed in dB.
203 3.1.9
204 steady state power offset
205 difference between the final and initial output power of the OA, prior to the power excursion
206 stimulus event
207 Note 1 to entry: Normally, the steady state power level following a power excursion differs from the OA power
208 before the input power stimulus event. The transient controller attempts to overcome this offset using feedback.
209 Note 2 to entry: Steady state power offset is expressed in dB.
210 3.2 Abbreviations
211 AFF ASE flattening filter
212 AGC automatic gain controller
213 APC automatic power control
214 ASE amplified spontaneous emission
215 ASEP amplified spontaneous emission power
216 BER bit error ratio
217 DFB distributed feedback (laser)
218 DWDM dense wavelength division multiplexing
219 EDF Erbium-doped fibre
220 EDFA Erbium-doped fibre amplifier
221 GFF gain flattening filter
222 NEM network equipment manufacturers
223 NSP network service providers
224 O/E optical-to-electrical
225 OA optical amplifier
226 OD optical damage
227 OFA optical fibre amplifier
228 OSA optical spectrum analyser
229 OSNR optical signal-to-noise ratio
230 PDs photodiodes
231 PID proportional integral derivative
232 SOA semiconductor optical amplifier
233 Sig_ASE signal-to-ASE ratio
234 SigP signal power
235 SOP state of polarization
236 VOA variable optical attenuator
237 WDM wavelength division multiplexing

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238 4 Apparatus
239 4.1 Test set-up
240 Figure 1 shows a generic set-up to characterise the transient response properties of output
241 power controlled single channel OAs.
OA
Channel pass-
Optical
Polarization
under
Laser source VOA
band filter
modulator
scrambler
test
O/E converter
Function generator
Oscilloscope
IEC
242
243 Figure 1 – Power transient test set-up
244 4.2 Characteristics of test equipment
245 The test equipment listed below is needed, with the required characteristics:
246 a) Laser source for supplying the OA input signal with the following characteristics:
247 – Ability to support the range of signal wavelengths for which the OA under test is to be
248 tested. This could be provided for example by a tuneable laser, or a bank of distributed
249 feedback (DFB) lasers;
250 – An achievable average output power such that at the input to the OA under test, the
251 power will be above the maximum specified input power of the OA, including loss of
252 any subsequent test equipment between the laser source and OA under test.
253 b) Polarization scrambler to randomize the incoming polarization state of the laser source, or
254 to control it to a defined state of polarization (SOP). The polarization scrambler is
255 optional.
256 c) Variable optical attenuator (VOA) with a dynamic range sufficient to support the required
257 range of surviving signal levels at which the OA under test is to be tested.
258 NOTE If the output power of the laser source can be varied over the required dynamic range, then a VOA is
259 not needed.
260 d) Optical modulator to modify the OA input signal to the defined power excursion with the
261 following characteristics.
262 – Extinction ratio at rewrite without putting number higher than the maximum drop level
263 for which the OA under test is to be tested;
264 – Switching time fast enough to support the fastest slew rate for which the OA under test
265 is to be tested.
266 e) Channel pass-band filter: an optical filter designed to distinguish the signal wavelength
267 with the following characteristics. Note the use of a channel pass-band filter is optional.
268 – Ability to support the range of signal wavelengths for which the OA under test is to be
269 tested. This could be provided for example by a tuneable filter, or a series of discrete
270 filters;
271 – 1dB pass-band of at least ±20 GHz centred around the signal wavelength;
272 – At least 20 dB attenuation level below the minimum insertion loss across the entire
273 specified transmission band of the OA under test, except within a range of ±100 GHz
274 centred around the signal wavelength.

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275 f) Opto-electronic (O/E) convertor to detect the filtered output of the OA under test with the
276 following characteristics:
277 – A sufficiently wide optical and electrical bandwidth to support the fastest slew rate for
278 which the OA is to be tested;
279 – A linear response within a ±5 dB range of all signal levels for which the OA under test
280 is to be tested.
281 g) Oscilloscope to measure and capture the transient response of the optically filtered output
282 of the OA under test, with a sufficiently wide electrical bandwidth to support the fastest
283 slew rate for which the OA is to be tested.
284 h) Function generator to generate the input power transient waveforms to drive the optical
285 modulator, with electrical pulse width short enough and electrical slew rate high enough to
286 support the fastest slew rate for which the OA under test is to be tested.
287 5 Test sample
288 The OA shall operate under nominal operating conditions. If the OA is likely to cause laser
289 oscillations due to unwanted reflections, optical isolators should be used to isolate the OA
290 under test. This will minimize signal instability.
291 6 Procedure
292 6.1 Test preparation
293 In the set-up shown in Figure 1, the input optical signal power injected into the amplifier being
294 tested is generated from a suitable laser source. The optical power is passed through an
295 optional polarization scrambler to allow randomization or control of the signal polarization
296 state and is subsequently adjusted with a VOA to the desired optical input power levels. The
297 signal then passes through an optical modulator driven by a function generator that provides
298 the desired input power test waveform to stimulate the transient input power excursions. The
299 signal is then injected into the amplifier being tested. A channel pass-band filter (such as a
300 tuneable optical filter, fixed optical filter or similar component) may be used to select only the
301 relevant channel wavelength under test, followed by an O/E converter and an oscilloscope at
302 the output of the amplifier. The output channel selected by the optional channel pass-band
303 filter and its transient response is monitored with the O/E converter and oscilloscope.
304 Waveforms similar to those shown in Figure A.3 are captured via the oscilloscope for
305 subsequent computer processing.
306 Prior to measurement of the transient response, the input power waveform trace shall be
307 recorded. Use the set-up of Figure 1 without the OFA under test. The input optical connector
308 from the optical modulator is connected to the channel pass filter.
309 For this test to stimulate a power excursion at the input of the OA under test, the source laser
310 power at the OA input is set at some typical power level. The function generator waveform is
311 chosen to increase or decrease the input power to the OA under test with power excursions
312 and slew rate relevant to the defined test condition. For example, for a typical number in the
313 case of an optical receiver, the input power to the OA could be increased by 7 dB in a
314 timeframe of 50 µs and then held at this power value to simulate a power increase transient
315 power response (step transient) condition as shown in Figure A.1(1). For alternative transient
316 control measurements, the signal generator waveform is controlled appropriately, and the
317 VOA is adjusted accordingly.
318 6.2 Test conditions
319 Several sequential transient control measurements can be performed according to the OA’s
320 specified operating conditions. Examples of power excursion scenarios are shown in Table 1.
321 These measurements are typically performed over a broad range of input power levels.

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322 Table 1 – Examples of transient control measurement test conditions
Scenario Power excursion Slew rate
Input power step transient increase/reduction 3 dB, 7 dB 500 µs, 200 µs, 50 µs
Input power pulse transient 3 dB, 7 dB
500 µs, 200 µs, 50 µs
Input power lightning bolt transient ±3 dB, ±7 dB 500 µs, 200 µs, 50 µs
323
324 7 Calculations
325 Transient parameters can be calculated by processing amplifier output power transient
326 waveforms shown in Figure 2, using the following criteria.
327 – Transient power response (dB) = B – A
328 – Transient power overcompensation response (dB) = G – A
329 – Steady state power offset (dB) = E – A
330 – Transient power response time (μs) = D – C

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B
E
A
G
C D
Time,  s
331
IEC
332 a) Channel input power increase
G
A
E
B
C D
Time,  s
IEC
333
334 b) Channel input power decrease
335 Figure 2 – OA output power transient response of a) input power increase
336 8 Test results
337 8.1 Test settings
338 The following test setting conditions shall be recorded:
339 a) Arrangement of the test set-up
340 b) Details (make and model) of each piece of test equipment
341 c) Set-up condition of each piece of test equipment (e.g. operating speed of polarization
342 scrambler, resolution bandwidth of optical spectrum analyzer (OSA))
343 d) Mounting method of test sample
344 e) Ambient conditions for the test sample
Power, dBm
Power,  dBm

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345 f) Input optical wavelength λ
in
346 8.2 Test data
347 The following test data shall be recorded:
348 a) Input optical power, P trace
in
349 b) Output optical power P trace
out
350 c) Signal-to-ASE ratio (SAR) at operating condition before and after excursion
351 d) OFA laser pump power before and after excursion
352 e) OA reported input power before and after input excursion (where available)
353 f) OA reported o
...