SIST EN 62007-2:2009

Semiconductor optoelectronic devices for fibre optic system applications - Part 2: Measuring methods (IEC 62007-2:2009)

This part of IEC 62007 describes the measuring methods applicable to the semiconductor optoelectronic devices to be used in the field of fibre optic digital communication systems and subsystems. All optical fibres and cables that are defined in IEC 60793 series, IEC 60794 series are applicable. All optical connectors that are defined in IEC 60874 series are applicable, if a pigtail is to be terminated with an optical connector.

Optoelektronische Halbleiterbauelemente für Anwendungen in Lichtwellenleitersystemen - Teil 2: Messverfahren (IEC 62007-2:2009)

Dispositifs optoélectroniques à semiconducteurs pour application dans les systèmes à fibres optiques - Partie 2: Méthodes de mesure (CEI 62007-2:2009)

La CEI 62007-2:2009 décrit les méthodes de mesure applicables aux dispositifs optoélectroniques à semi-conducteurs utilisés dans le domaine des systèmes et sous-systèmes de télécommunication numérique à fibres optiques. La présente édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:  - les descriptions relatives aux caractéristiques analogiques ont été retirées;  - certains termes et définitions ont été revus afin de les harmoniser avec ceux des autres normes émises par le SC 86C.

Polprevodniške optoelektronske naprave za uporabo v sistemih z optičnimi vlakni - 2. del: Merilne metode (IEC 62007-2:2009)

General Information

• Status: Published
• Publication Date: 31-Mar-2009
• ICS: 31.080.01 - Semiconductor devices in general
• ICS: 31.260 - Optoelectronics. Laser equipment
• ICS: 33.180.01 - Fibre optic systems in general
• Technical Committee: iTEL - Communication cables
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Mar-2009
• Due Date: 23-May-2009
• Completion Date: 01-Apr-2009
• Ref Project: EN 62007-2:2009 - Semiconductor optoelectronic devices for fibre optic system applications - Part 2: Measuring methods

Relations

• Replaces: SIST EN 62007-2:2002 - Semiconductor optoelectronic devices for fibre optic system applications -- Part 2: Measuring methods
• Effective Date: 01-May-2009
• Replaces: SIST EN 62007-2:2002 - Semiconductor optoelectronic devices for fibre optic system applications -- Part 2: Measuring methods
• Effective Date: 28-Jan-2023
• Replaces: SIST EN 62007-2:2002 - Semiconductor optoelectronic devices for fibre optic system applications -- Part 2: Measuring methods
• Effective Date: 13-May-2010
• Replaces: SIST EN 62007-2:2002 - Semiconductor optoelectronic devices for fibre optic system applications -- Part 2: Measuring methods
• Effective Date: 07-Jun-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 62007-2:2009
01-maj-2009
1DGRPHãþD
SIST EN 62007-2:2002
3ROSUHYRGQLãNHRSWRHOHNWURQVNHQDSUDYH]DXSRUDERYVLVWHPLK]RSWLþQLPLYODNQL
GHO0HULOQHPHWRGH,(&
Semiconductor optoelectronic devices for fibre optic system applications - Part 2:
Measuring methods (IEC 62007-2:2009)
Optoelektronische Halbleiterbauelemente für Anwendungen in Lichtwellenleitersystemen
- Teil 2: Messverfahren (IEC 62007-2:2009)
Dispositifs optoélectroniques à semiconducteurs pour application dans les systèmes à
fibres optiques - Partie 2: Méthodes de mesure (CEI 62007-2:2009)
Ta slovenski standard je istoveten z: EN 62007-2:2009
ICS:
31.080.01 Polprevodniški elementi Semiconductor devices in
(naprave) na splošno general
31.260 Optoelektronika, laserska Optoelectronics. Laser
oprema equipment
33.180.01 6LVWHPL]RSWLþQLPLYODNQLQD Fibre optic systems in
VSORãQR general
SIST EN 62007-2:2009 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 62007-2:2009

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SIST EN 62007-2:2009

EUROPEAN STANDARD
EN 62007-2

NORME EUROPÉENNE
March 2009
EUROPÄISCHE NORM

ICS 31.080.01; 31.260; 33.180.01 Supersedes EN 62007-2:2000


English version


Semiconductor optoelectronic devices
for fibre optic system applications -
Part 2: Measuring methods
(IEC 62007-2:2009)


Dispositifs optoélectroniques  Optoelektronische Halbleiterbauelemente
à semiconducteurs pour application für Anwendungen
dans les systèmes à fibres optiques - in Lichtwellenleitersystemen -
Partie 2: Méthodes de mesure Teil 2: Messverfahren
(CEI 62007-2:2009) (IEC 62007-2:2009)




This European Standard was approved by CENELEC on 2009-02-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: avenue Marnix 17, B - 1000 Brussels


© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62007-2:2009 E

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SIST EN 62007-2:2009
EN 62007-2:2009 - 2 -
Foreword
The text of document 86C/868/FDIS, future edition 2 of IEC 62007-2, prepared by SC 86C, Fibre optic
systems and active devices, of IEC TC 86, Fibre optics, was submitted to the IEC-CENELEC parallel vote
and was approved by CENELEC as EN 62007-2 on 2009-02-01.
This European Standard supersedes EN 62007-2:2000.
EN 62007-2:2009 includes the following significant technical changes with respect to EN 62007-2:2000:
– descriptions related to analogue characteristics have been removed;
– some definitions and terms have been revised for harmonisation with other standards originating from
SC 86C.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2009-11-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2012-02-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62007-2:2009 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 61300 NOTE  Harmonized in EN 61300 series (not modified).
IEC 61315 NOTE  Harmonized as EN 61315:2006 (not modified).
ISO 1101 NOTE  Harmonized as EN ISO 1101:2005 (not modified).
__________

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SIST EN 62007-2:2009
- 3 - EN 62007-2:2009
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. 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 60050-731 1991 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 731: Optical fibre communication


IEC 60793 (mod) Series Optical fibres EN 60793 Series


IEC 60794 Series Optical fibre cables EN 60794 Series


IEC 60874 Series Connectors for optical fibres and cables EN 60874 Series

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SIST EN 62007-2:2009

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SIST EN 62007-2:2009
IEC 62007-2
Edition 2.0 2009-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Semiconductor optoelectronic devices for fibre optic system applications –
Part 2: Measuring methods

Dispositifs optoélectroniques à semiconducteurs pour application dans les
systèmes à fibres optiques –
Partie 2: Méthodes de mesure

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
W
CODE PRIX
ICS 31.080.01; 31.260; 33.180.01 ISBN 2-8318-1023-6
® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN 62007-2:2009
– 2 – 62007-2 © IEC:2009
CONTENTS
FOREWORD.0H4
INTRODUCTION.1H6
1 Scope.2H7
2 Normative references .3H7
3 Terms, definitions and abbreviations .4H7
3.1 Terms and definitions .5H7
3.2 Abbreviations .6H8
4 Measuring methods for photoemitters .7H8
4.1 Outline of the measuring methods .8H8
4.2 Radiant power or forward current of LEDs and LDs with or without optical
fibre pigtails .9H8
4.3 Small signal cut-off frequency (f ) of LEDs and LDs with or without optical
c
fibre pigtails .10H9
4.4 Threshold current of LDs with or without optical fibre pigtails .11H10
4.5 Relative intensity noise of LEDs and LDs with or without optical fibre pigtails.12H12
4.6 S parameter of LEDs, LDs and LD modules with or without optical fibre
11
pigtails .13H13
4.7 Tracking error for LD modules with optical fibre pigtails, with or without
cooler.14H15
4.8 Spectral linewidth of LDs with or without optical fibre pigtails .15H17
4.9 Modulation current at 1 dB efficacy compression (I ) of LEDs .16H18
F (1 dB)
4.10 Differential efficiency (η ) of a LD with or without pigtail and an LD module .17H20
d
4.11 Differential (forward) resistance r of an LD with or without pigtail .18H22
d
5 Measuring methods for receivers.19H23
5.1 Outline of the measuring methods .20H23
5.2 Noise of a PIN photodiode.21H23
5.3 Excess noise factor of an APD with or without optical fibre pigtails.22H25
5.4 Small-signal cut-off frequency of a photodiode with or without optical fibre
pigtails .23H27
5.5 Multiplication factor of an APD with or without optical fibre pigtails .24H28
5.6 Responsivity of a PIN-TIA module .25H30
5.7 Frequency response flatness (ΔS/S) of a PIN-TIA module .26H32
5.8 Output noise power (spectral) density P of a PIN-TIA module.27H33
λ
no,
5.9 Low frequency output noise power (spectral) density (P ) and corner
,λ,
no LF
frequency (f ) of a PIN-TIA module .28H35
cor
5.10 Minimum detectable power of PIN-TIA module .29H36
Bibliography.30H38

Figure 1 – Equipment setup for measuring radiant power and forward current of LEDs
and LDs .31H8
Figure 2 – Circuit diagram for measuring small-signal cut-off frequency LEDs and LDs .32H10
Figure 3 – Circuit diagram for measuring threshold current of a LD.33H11
Figure 4 – Graph to determine threshold current of lasers.34H11
Figure 5 – Circuit diagram for measuring RIN of LEDs and LDs .35H12
Figure 6 – Circuit diagram for measuring the S parameter LEDs, LDs and LD
11
modules.36H14

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SIST EN 62007-2:2009
62007-2 © IEC:2009 – 3 –
Figure 7– Cathode and anode connected to the package of a LD.37H15
Figure 8 – Output radiant power versus time.38H16
Figure 9 – Output radiant power versus case temperature .39H16
Figure 10 – Circuit diagram for measuring linewidth of LDs.40H17
Figure 11 – Circuit diagram for measuring 1 dB efficacy compression of LDs.41H19
Figure 12 – Plot of log V versus log I .42H20
2 1
Figure 13 – Circuit diagram for measuring differential efficiency of a LD .43H21
Figure 14 – Current waveform for differential efficiency measurement .44H21
Figure 15 – Circuit diagram for measuring differential resistance .45H22
Figure 16 – Current waveform for differential resistance .46H23
Figure 17 – Circuit diagram for measuring noise of a PIN photoreceiver .47H24
Figure 18 – Circuit diagram for measuring noise with synchronous detection .48H25
Figure 19 – Circuit diagram for measuring excess noise of an APD.49H26
Figure 20 – Circuit diagram for measuring small-signal cut-off wavelength of a
photodiode.50H28
Figure 21 – Circuit diagram for measuring multiplication factor of an APD .51H29
Figure 22 – Graph showing measurement of I and I .52H30

R1 R2
Figure 23 – Circuit diagram for measuring responsivity of a PIN-TIA module .53H31
Figure 24 – Circuit diagram for measuring frequency response flatness of a PIN-TIA
module.54H32
Figure 25 – Circuit diagram for measuring output noise power (spectral) density of a
PIN-TIA module under matched output conditions.55H34
Figure 26 – Circuit diagram for measuring output noise power (spectral) density of a
non-irradiated PIN-TIA module in the low frequency region.56H35
Figure 27 – Graph of V versus frequency.57H36
m
Figure 28 – Circuit diagram for measuring minimum detectable power of a PIN-TIA
module at a specified bit-error rate (BER) or carrier-to-noise ratio (C/N) .58H37

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SIST EN 62007-2:2009
– 4 – 62007-2 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

SEMICONDUCTOR OPTOELECTRONIC DEVICES
FOR FIBRE OPTIC SYSTEM APPLICATIONS –

Part 2: Measuring methods


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62007-2 has been prepared by subcommittee 86C: Fibre optic
systems and active devices, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition published in 1997, and its
amendment 1(1998). It is a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) descriptions related to analogue characteristics have been removed;
b) some definitions and terms have been revised for harmonisation with other standards
originating from SC 86C.

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SIST EN 62007-2:2009
62007-2 © IEC:2009 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
86C/868/FDIS 86C/870/RVD

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 of the IEC 62007 series can be found, under the general title Semiconductor
optoelectronic devices for fibre optic system applications, on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.

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SIST EN 62007-2:2009
– 6 – 62007-2 © IEC:2009
INTRODUCTION
Semiconductor optical signal transmitters and receivers play important roles in optical
information networks. This standard covers the measurement procedures for their optical and
electrical properties that are intended for digital communication systems. These properties are
essential to specify their performance.

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SIST EN 62007-2:2009
62007-2 © IEC:2009 – 7 –
SEMICONDUCTOR OPTOELECTRONIC DEVICES
FOR FIBRE OPTIC SYSTEM APPLICATIONS –

Part 2: Measuring methods



1 Scope
This part of IEC 62007 describes the measuring methods applicable to the semiconductor
optoelectronic devices to be used in the field of fibre optic digital communication systems and
subsystems.
All optical fibres and cables that are defined in IEC 60793 series, IEC 60794 series are
applicable. All optical connectors that are defined in IEC 60874 series are applicable, if a
pigtail is to be terminated with an optical connector.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050-731:1991, International Electrotechnical Vocabulary – Chapter 731: Optical fibre
communication
IEC 60793 (all parts), Optical fibres
IEC 60794 (all parts), Optical fibre cables
IEC 60874 (all parts), Connectors for optical fibres and cables
3 Terms, definitions and abbreviations
For the purposes of this document, the following terms, definitions and abbreviations apply.
3.1 Terms and definitions
3.1.1
PIN photodiode
photodiode with a large intrinsic region sandwiched between p- and n-doped semiconducting
regions used for the detection of optical radiation
[IEV 731-06-29]
3.1.2
avalanche photodiode
photodiode operating with a bias voltage such that the primary photocurrent undergoes
amplification by cumulative multiplication of charge carriers
[IEV 731-06-30]
3.1.3
pigtail
short optical fibre or optical fibre cable that is attached to a device being measured

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SIST EN 62007-2:2009
– 8 – 62007-2 © IEC:2009
3.2 Abbreviations
LED light emitting diodes
LD laser diode
PD photodiode
TIA transimpedance amplifier
APD avalanche photodiode
4 Measuring methods for photoemitters
4.1 Outline of the measuring methods
The LEDs and LDs have various opto-electronic properties. Some of them are important
specifications for using them in the optical communication systems. The measuring methods
for their opto-electronic properties are described in the following subclauses. Each subclause
consists of following items.
a) Purpose
b) “Equipment setup” or “Circuit diagram” for measurement
c) “Equipment descriptions and requirements” or “Circuit descriptions and requirements”
d) Precautions to be observed
e) Measurement procedures
f) Specified conditions
4.2 Radiant power or forward current of LEDs and LDs with or without optical fibre
pigtails
a) Purpose
To measure the radiant power Φ or the forward current I of light-emitting diodes (LED)
e F
and laser diodes, with or without optical fibre pigtails, under specified conditions.
b) Measuring equipment
Figure 1 shows an equipment setup for measuring radiant power and forward current of
LEDs and LDs.

Integrating sphere
Detector (calibrated)
Device being measured
Diffusing opaque screen
I
F
IEC  2305/08

Figure 1 – Equipment setup for measuring radiant power
and forward current of LEDs and LDs
c) Equipment description and requirements
The radiation emitted by the device is submitted to multiple reflections from the walls
of the integrating sphere; this leads to a uniform irradiance of the surface proportional to

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SIST EN 62007-2:2009
62007-2 © IEC:2009 – 9 –
the emitted flux. A detector located in the walls of the sphere measures this irradiance. An
opaque screen shields the detector from the direct radiation of the device being measured.
d) Precautions to be observed
The device being measured, the screen and the apertures shall be small compared to the
sphere surface.
The inner surface of the sphere and screen shall have a diffusing coating having a high
uniform reflection coefficient (0,8 minimum).
The sphere and detector assembly shall be calibrated.
Change in peak-emission wavelength and flux due to power dissipation shall be taken into
account.
When the device being measured is pulsed, the detector shall average the measured
radiation.
e) Measurement procedures
The emitting device is set at the entrance of the integrating sphere, so that no direct
radiation will reach the detector.
For measurement of radiant power, the specified forward current I is applied to the device
F
and the radiant power is measured on the photodetector.
For measurement of forward current, a current is applied to the device until the specified
radiant power (Φ ) is achieved. The value of current is recorded.
e
f) Specified conditions
– Ambient or case temperature.
– Radiant power (when measuring forward current).
– Forward current (when measuring radiant power).
4.3 Small signal cut-off frequency (f ) of LEDs and LDs with or without optical fibre
c
pigtails
a) Purpose
To measure the small-signal cut-off frequency (f ) of light-emitting diodes (LED) and laser
c
diodes (LD) with or without optical fibre pigtails, under specified conditions.
b) Circuit diagram
Figure 2 shows a circuit diagram for measuring small-signal cut-off frequency
LEDs and LDs.

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SIST EN 62007-2:2009
– 10 – 62007-2 © IEC:2009

C
1
+
G C
1
2
D
G PD M
2
–
IEC  2306/08

Key
D device being measured
G adjustable frequency a.c. generator
1
G d.c. generator
2
PD photodetector
M measuring instrument for a.c. radiant power
C , C coupling capacitors
1 2
Figure 2 – Circuit diagram for measuring small-signal
cut-off frequency LEDs and LDs
c) Precautions to be observed
The radiant power reflected back into the laser-diode shall be minimized so as to avoid
distortions, which could affect the accuracy of the measurements. The photodetector must
have a frequency response greater than f .
c
d) Measurement procedure
For LEDs, the specified direct forward current or the direct forward current required to
obtain the specified radiant power is applied to the device being measured.
For laser diodes, the forward current is adjusted to a value equal to the continuous
forward current above the threshold or specified radiant power.
The forward current is modulated using generator G at a low frequency (less than f /100)
1 c
and the a.c. radiant power is measured on M (see Figure 2).
The modulation frequency is increased, keeping the modulation level constant until the
output radiant power measured on M has halved.
This frequency is the small-signal cut-off frequency (f ).
c
e) Specified conditions
For the light-emitting diodes (LED):
– ambient or case temperature;
– d.c. forward current or radiant power.
For the laser diodes (LD):
– ambient, case or submount temperature;
–  difference between (actual) d.c. forward current and threshold current or radiant power.
4.4 Threshold current of LDs with or without optical fibre pigtails
a) Purpose
To measure the threshold current of a laser diode, with or without optical fibre pigtails.
b) Circuit diagram
Figure 3 shows a circuit diagram for measuring threshold current of a laser diode.

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SIST EN 62007-2:2009
62007-2 © IEC:2009 – 11 –

+
D PD
G
–
A
IEC  2307/08

Key
D device being measured
PD photodetector measuring incident radiant power
A ammeter
G generator (pulsed or d.c.)
Figure 3 – Circuit diagram for measuring threshold current of a LD
c) Circuit description and requirements
For pulse measurement, the current generator, G, shall provide current pulses of the
required amplitude, duration and repetition rate.
d) Precautions to be observed
Radiant power reflected back into the laser diode shall be minimized. The limiting values
of the laser diode (I and Φ ) shall not be overstepped.
F e
e) Measurement procedure
A forward current is applied to the diode and the relation between the incident radiant
power from the diode and the forward current is recorded.
The forward current at which the second derivative of the recorded curve showing incident
radiant power versus the forward current has its first maximum is determined (see
Figure 4). The forward current at this point is the threshold current I .
TH
f) Specified conditions
– Ambient, case or submount temperature.
– For pulse measurement, repetition frequency and pulse duration of the forward
current.
Figure 4 shows a graph to determine threshold current of lasers.
2
d Φ
e
Φ
e 2
dI

F
2
d Φ
e
2
Φ
e
dI

F
I I
TH F
IEC  2308/08

Figure 4 – Graph to determine threshold current of lasers

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SIST EN 62007-2:2009
– 12 – 62007-2 © IEC:2009
4.5 Relative intensity noise of LEDs and LDs with or without optical fibre pigtails
a) Purpose
To measure the relative intensity noise (RIN) of light emitting diodes (LED) and laser
diodes (LD), with or without optical fibre pigtails, under specified conditions.
b) Circuit diagram
Figure 5 shows a circuit diagram for measuring RIN of LEDs and LDs.

L
I
I
F R(H)
D PD
AMP F
+
G
1
+
–
R
L G M
2
–
IEC  2309/08

Key
G d.c. current generator
1
D device being measured
L lens system
I forward current
F
PD photodetector
R load resistance
L
I reverse current of the photodetector under optical radiation

R(H)
G d.c. voltage bias generator
2
AMP a.c. amplifier with gain G
F filter with centre frequen
...