IEC 61300-3-21:2014

IEC 61300-3-21 ®
Edition 2.0 2014-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures –
Part 3-21: Examinations and measurements – Switching time

Dispositifs d’interconnexion et composants passifs à fibres optiques –
Procédures fondamentales d'essais et de mesures –
Partie 3-21: Examens et mesures – Temps de commutation

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IEC 61300-3-21 ®
Edition 2.0 2014-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Fibre optic interconnecting devices and passive components – Basic test and

measurement procedures –
Part 3-21: Examinations and measurements – Switching time

Dispositifs d’interconnexion et composants passifs à fibres optiques –

Procédures fondamentales d'essais et de mesures –

Partie 3-21: Examens et mesures – Temps de commutation

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX L
ICS 33.180.20 ISBN 978-2-8322-1536-4

– 2 – IEC 61300-3-21:2014 © IEC 2014

CONTENTS
FOREWORD . 3

1 Scope . 5

2 Normative references . 5

3 Terms and definitions . 5

4 Apparatus . 7

4.1 General description . 7

4.2 Optical source (S) . 7
4.3 Excitation unit (E) . 7
4.4 Detector (D) . 7
4.5 Actuation energy supply . 7
4.6 Data Acquisition System (DAS) . 7
4.7 Termination (T) . 7
4.8 Temporary joint (TJ) . 8
5 Procedure . 8
6 Details to be specified . 9
Bibliography . 10

Figure 1 – Measurement set-up using a 2-channel oscilloscope as DAS to measure a
single output port . 8
Figure 2 – Example of a port moving to an on-state or off-state . 9

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
FIBRE OPTIC INTERCONNECTING DEVICES AND PASSIVE COMPONENTS –

BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-21: Examinations and measurements – Switching time

FOREWORD
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 61300-3-21 has been prepared by subcommittee 86B: Fibre optic
interconnecting devices and passive components, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition published in 1998. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) removal of “bounce time” from the title;
b) update and alignment of definitions with IEC 60876-1;
c) generalization of the detection apparatus beyond an oscilloscope.

– 4 – IEC 61300-3-21:2014 © IEC 2014

The text of this standard is based on the following documents:

CDV Report on voting
86B/3623/CDV 86B/3702/RVC
Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 61300 series, published under the general title, Fibre optic
interconnecting devices and passive components – Basic test and measurement procedures,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
FIBRE OPTIC INTERCONNECTING DEVICES AND PASSIVE COMPONENTS –

BASIC TEST AND MEASUREMENT PROCEDURES –

Part 3-21: Examinations and measurements – Switching time

1 Scope
This part of IEC 61300 is a method to measure the switching time and related performance
parameters of an optical switch when the actuation energy is applied or removed to change the
state of the switch.
2 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 61300-3-4, Fibre optic interconnecting devices and passive components – Basic test and
measurement procedures – Part 3-4: Examinations and measurements – Attenuation
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
latency time
3.1.1
latency time
elapsed time until the output power of a
specified output port reaches 10 % of its steady-state value of the output power from the time
the actuation energy is applied for a normally-on switch or is removed for a normally-off switch

[SOURCE: IEC 60876-1:2012, 3.3.4.1, modified – “for a normally-on switch or is removed for a
normally-off switch” has been added.]
3.1.2
latency time
elapsed time until the output power of a
specified output port reaches 90 % of its steady-state value of the output power from the time
the actuation energy is removed for a normally-on switch or is applied for a normally-off switch
Note 1 to entry: For a latch type optical switch, in case of switching from conducting state to isolated state,
actuation energy is applied or removed.
[SOURCE: IEC 60876-1:2012, 3.3.4.2, modified – “for a normally-on switch or is removed for a
normally-off switch” and Note 1 to entry have been added.]

– 6 – IEC 61300-3-21:2014 © IEC 2014

3.2
rise time
elapsed time for the output power of the specified output port to rise from 10 % of the steady-

state conducting value to 90 % of the steady-state conducting value

[SOURCE: IEC 60876-1:2012, 3.3.5, modified – “conducting” has been added.]

3.3
fall time
elapsed time for the output power of the specified output port to fall from 90 % of the steady-

state conducting value to 10 % of the steady-state conducting value

[SOURCE: IEC 60876-1:2012, 3.3.6, modified – “conducting” has been added.]
3.4
bounce time
3.4.1
bounce time
elapsed time until the output power of a
specified output port is maintained between 90 % and 110 % of its steady-state value of the
output power from the first time the output power of a specified output port reaches 90 % of its
steady-state value of the output power
[SOURCE: IEC 60876-1:2012, 3.3.7.1]
3.4.2
bounce time
elapsed time until the output power of a
specified output port is maintained between 0 % and 10 % of its steady-state conducting value
of the output power from the first time the output power of a specified output port reaches 10 %
of its steady-state conducting value of the output power
[SOURCE: IEC 60876-1:2012, 3.3.7.2]
3.5
switching time
3.5.1
switching time


t = t + t+ t
s l r b
where t , t , and t are the latency time, rise time, and bounce time, respectively
l r b
[SOURCE: IEC 60876-1:2012, 3.3.8.1]
3.5.2
switching time

t = t + t + t
s l’ f b’
where t , t , and t are the latency time, fall time, and bounce time, respectively
l’ f b’
[SOURCE: IEC 60876-1:2012, 3.3.8.2]

4 Apparatus
4.1 General description
For each optical path through the switch that is to be tested, a stable optical signal from an

optical source is applied to the input port(s) and the time-dependent optical signal level at the

output port(s) is measured with respect to the time when the actuation energy specified in the

relevant specification is applied or removed.

4.2 Optical source (S)
The source output power shall be sufficiently stable over the time required to perform the
measurements. Unless otherwise specified, the optical power stability shall follow IEC 61300-3-
4. The source shall be capable of producing the spectral characteristics defined in the relevant
specification (both wavelength and spectral width).
If the optical source is polarized, as is usual for laser sources, then the measurement and
especially the steady-state conducting value of the output power will be influenced by any
polarization dependence in the switch, joints, or detector. Stable environmental conditions and
fibre positioning are recommended to avoid changes in the polarization state during the
measurement.
4.3 Excitation unit (E)
This is a special launch fibre or imaging system designed to achieve the required launch
conditions. The excitation unit shall follow IEC 61300-1.
4.4 Detector (D)
The detector produces an electrical signal proportional to the input optical power and shall
have sufficient speed to measure the switching time and bounce time to the accuracy specified
in the relevant specification. The response time of the detector should be less than or equal to
one tenth the rise time or fall time to be measured. The detector shall have sufficient dynamic
range to make the measurement and have linear response over the optical power levels
expected to be encountered. The detector shall have sufficiently high return loss to prevent
impact on the measurements. The return loss of the measurement system should be 30 dB or
higher. Multiple detectors may be used to measure multiple optical ports simultaneously.
4.5 Actuation energy supply
The rise time and fall time of the actuation energy supply should be less than or equal to one
tenth the rise time or fall time of the optical switch specification. The duration of the actuation
energy shall be sufficiently longer than the anticipated bounce time, for non-latch type optical

switches.
4.6 Data acquisition system (DAS)
The data acquisition system records the time-dependence of the optical power, referred to the
time that the actuation energy is applied or removed and shall have sufficient data storage
capacity, bandwidth and accuracy. It shall have the capability for at least two traces, or one
trace that is synchronized by a hardware or software trigger to the actuation energy. An
oscilloscope may be used for data acquisition or the detector and data acquisition functions
may be integrated in a data-logging optical power meter.
4.7 Termination (T)
These terminations are components or techniques to suppress reflected light from the DUT
output ports. Impairment of the measurement by reflections at the fibre output to the detector(s)
should also be avoided. Fibre optic connectors with angled polished contacting (APC) face are
usually sufficient. If the switch has non-angled-polished connectors, these can be terminated

– 8 – IEC 61300-3-21:2014 © IEC 2014

by connecting to a cord with a non-angled-polished connector and an angled-polished

connector at the other end.
4.8 Temporary joint (TJ)
This is a method, device, or mechanical fixture for temporarily aligning two fibre ends into a

reproducible, low loss joint. It may, for example, be a precision V-groove vacuum chuck, micro-

manipulator, or a fusion or mechanical splice. The stability of the temporary joint shall be

compatible with the measurement precision required.

5 Procedure
The procedure is illustrated here for a switch containing integral fibre optic pigtails without
connectors (configuration A switch, see IEC 60876-1). For switches configured with fibre optic
connectors on the pigtails or housing (configurations B or C), the appropriate fibre cords and
connectors shall be used in the place of the temporary joints. When multiple output ports are
measured, each may be connected to a detector and it should be assured that impairment from
reflections is avoided.
a) Configure the switching time and bounce time measurement set-up as shown in Figure 1.
Connect the detector output to channel 1 of the data acquisition system. Additional
detectors may be used in the same way. Connect the actuation energy supply to the optical
switch and to channel 2 or the trigger input of the data acquisition system, as shown in
Figure 1.
TJ TJ
1 2
CH 1
D
S E Optical
switch
DAS
CH 2
T T
Actuation
energy
supply
IEC  1051/14
Figure 1 – Measurement set-up using a 2-channel
oscilloscope as DAS to measure a single output port
b) When the actuation energy specified in the relevant specification is supplied or removed,
record the change in the optical power level over enough time to establish the steady-state
optical power level. Using the 10 % and 90 % power levels, determine the switching time t ,
s
rise time t or fall time t , and bounce time t , as shown in Figure 2. In the case in which,
...