SIST EN ISO 13694:2016
(Main)Optics and photonics - Lasers and laser-related equipment - Test methods for laser beam power (energy) density distribution (ISO 13694:2015)
Optics and photonics - Lasers and laser-related equipment - Test methods for laser beam power (energy) density distribution (ISO 13694:2015)
This International Standard specifies methods by which the measurement of power [energy] density
distribution is made and defines parameters for the characterization of the spatial properties of laser
power [energy] density distribution functions at a given plane.
The methods given in this International Standard are intended to be used for the testing and
characterization of both continuous wave (cw) and pulsed laser beams used in optics and optical
instruments.
Optik und Photonik - Laser und Laseranlagen - Prüfverfahren für die Leistungs-(Energie-)dichteverteilung von Laserstrahlen (ISO 13694:2015)
Diese Internationale Norm legt Verfahren zur Messung der Leistungs-[Energie-]dichteverteilung fest und definiert Parameter zur Charakterisierung der räumlichen Eigenschaften von Laserleistungs-[Energie-]dichteverteilungsfunktionen in einer gegebenen Ebene.
Die in dieser Internationalen Norm beschriebenen Prüfverfahren sind zur Prüfung und Charakterisierung der Strahlen von Dauerstrichlasern wie auch von Pulslasern in der Optik und optischen Elementen bestimmt.
Optique et photonique - Lasers et équipements associés aux lasers - Méthodes d'essai de distribution de la densité de puissance (d'énergie) du faisceau laser (ISO 13694:2015)
ISO 13694:2015 spécifie des méthodes permettant de procéder au mesurage de la distribution de densité de puissance [d'énergie] et définit les paramètres de caractérisation des propriétés spatiales des fonctions de distribution de densité de puissance [d'énergie] laser dans un plan donné.
Les méthodes d'essai données dans la présente Norme internationale sont destinées à être utilisées dans le cadre des essais (cw) et de la caractérisation des faisceaux laser continus et impulsionnels.
Optika in fotonska tehnologija - Laserji in laserska oprema - Preskusne metode za gostoto porazdelitve moči (energije) žarka (ISO 13694:2015)
Ta mednarodni standard določa metode, s katerimi se izvaja merjenje gostote porazdelitve moči [energije], ter parametre za karakterizacijo prostorskih lastnosti funkcij gostote porazdelitve moči [energije] na dani ravnini. Metode, podane v okviru tega mednarodnega standarda, so namenjene preskušanju in karakterizaciji tako trajnih valov (cw) ter tudi pulznih laserskih žarkov, ki se uporabljajo v optiki in optičnih instrumentih.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 13694:2016
01-marec-2016
1DGRPHãþD
SIST EN ISO 13694:2000
SIST EN ISO 13694:2000/AC:2008
2SWLNDLQIRWRQVNDWHKQRORJLMD/DVHUMLLQODVHUVNDRSUHPD3UHVNXVQHPHWRGH]D
JRVWRWRSRUD]GHOLWYHPRþL HQHUJLMH åDUND ,62
Optics and photonics - Lasers and laser-related equipment - Test methods for laser
beam power (energy) density distribution (ISO 13694:2015)
Optik und Photonik - Laser und Laseranlagen - Prüfverfahren für die Leistungs-(Energie
-)dichteverteilung von Laserstrahlen (ISO 13694:2015)
Optique et photonique - Lasers et équipements associés aux lasers - Méthodes d'essai
de distribution de la densité de puissance (d'énergie) du faisceau laser (ISO
13694:2015)
Ta slovenski standard je istoveten z: EN ISO 13694:2015
ICS:
31.260 Optoelektronika, laserska Optoelectronics. Laser
oprema equipment
SIST EN ISO 13694:2016 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 13694:2016
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SIST EN ISO 13694:2016
EN ISO 13694
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2015
EUROPÄISCHE NORM
ICS 31.260 Supersedes EN ISO 13694:2000
English Version
Optics and photonics - Lasers and laser-related equipment
- Test methods for laser beam power (energy) density
distribution (ISO 13694:2015)
Optique et photonique - Lasers et équipements Optik und Photonik - Laser und Laseranlagen -
associés aux lasers - Méthodes d'essai de distribution Prüfverfahren für die Leistungs-(Energie-
de la densité de puissance (d'énergie) du faisceau laser )dichteverteilung von Laserstrahlen (ISO 13694:2015)
(ISO 13694:2015)
This European Standard was approved by CEN on 19 September 2015.
CEN 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 CEN-CENELEC Management Centre or to any CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13694:2015 E
worldwide for CEN national Members.
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SIST EN ISO 13694:2016
EN ISO 13694:2015 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 13694:2016
EN ISO 13694:2015 (E)
European foreword
This document (EN ISO 13694:2015) has been prepared by Technical Committee ISO/TC 172 "Optics
and photonics" in collaboration with Technical Committee CEN/TC 123 “Lasers and photonics” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2016, and conflicting national standards shall be
withdrawn at the latest by June 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN ISO 13694:2000.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 13694:2015 has been approved by CEN as EN ISO 13694:2015 without any modification.
3
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SIST EN ISO 13694:2016
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SIST EN ISO 13694:2016
INTERNATIONAL ISO
STANDARD 13694
Second edition
2015-11-15
Optics and photonics — Lasers and
laser-related equipment — Test
methods for laser beam power
(energy) density distribution
Optique et photonique — Lasers et équipements associés aux
lasers — Méthodes d’essai de distribution de la densité de puissance
(d’énergie) du faisceau laser
Reference number
ISO 13694:2015(E)
©
ISO 2015
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Measured quantities . 1
3.2 Characterizing parameters . 3
4 Coordinate system . 6
5 Characterizing parameters derived from the measured spatial distribution .7
6 Test principle . 7
7 Measurement arrangement and test equipment . 7
7.1 General . 7
7.2 Preparation . 7
7.3 Control of environment . 8
7.4 Detector system . 8
7.5 Beam-forming optics, optical attenuators, and beam splitters . 8
8 Test procedure . 9
8.1 Equipment preparation . 9
8.2 Detector calibration procedure . 9
8.2.1 Spatial calibration . 9
8.2.2 Power [energy] calibration . 9
8.3 Data recording and noise correction .10
8.3.1 General.10
8.3.2 Correction by background-map subtraction .10
8.3.3 Correction by average background subtraction.11
9 Evaluation .11
9.1 Choice and optimization of integration limits .11
9.2 Control and optimization of background corrections .11
10 Test report .12
Annex A (informative) Test report .13
© ISO 2015 – All rights reserved iii
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 172, Optics and photonics, Subcommittee SC 9,
Electro-optical systems.
This second edition cancels and replaces the first edition (ISO 13694:2000), which has been technically
revised with the following changes:
a) the definition of power density distribution E (x, y, z) has been revised, a definition of the power
density E (x , y , z) has been added;
0 0
b) the definition of energy density distribution H (x, y, z) has been revised, a definition of the energy
density H (x , y , z) has been added;
0 0
c) the term “threshold power [energy] density” has been replaced by “clip-level power [energy]
density”. The index “T” indicating “threshold” has been replaced by “CL” accordingly;
d) the term “effective power [energy]” has been replaced by “clip-level power [energy]”;
e) in 3.2.5, the formula for beam ellipticity has been revised;
f) the term “effective irradiation area” has been replaced by “clip-level irradiation area”;
g) the notation Ez() [Hz() ] indicating the clip-level average power [energy] density has been
η η
replaced by Ez() , [Hz() ];
ηave ηave
h) Figure 1 has been revised taking into account the items a) and g) of this list.
It also incorporates the corrigendum ISO 13694:2000/Cor 1:2005.
iv © ISO 2015 – All rights reserved
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
Introduction
Many applications of lasers involve using the near-field as well as the far-field power [energy] density
distribution of the beam. The power [energy] density distribution of a laser beam is characterized
by the spatial distribution of irradiant power [energy] density with lateral displacement in a
particular plane perpendicular to the direction of propagation. In general, the power [energy] density
distribution of the beam changes along the direction of propagation. Depending on the power [energy],
size, wavelength, polarization, and coherence of the beam, different methods of measurement are
applicable in different situations. Five methods are commonly used: camera arrays (1D and 2D),
apertures, pinholes, slits, and knife edges.
This International Standard provides definitions of terms and symbols to be used in referring to power
density distribution, as well as requirements for its measurement. For pulsed lasers, the distribution of
time-integrated power density (i.e. energy density) is the quantity most often measured.
According to ISO 11145, it is possible to use two different definitions for describing and measuring
the laser beam diameter. One definition is based on the measurement of the encircled power [energy];
the other is based on determining the spatial moments of the power [energy] density distribution of
the laser beam.
The use of spatial moments is necessary for calculating the beam propagation factor, K, and the
2
beam propagation ratio, M , from measurements of the beam widths at different distances along the
propagation axis. ISO 11146 describes this measurement procedure. For other applications, other
definitions for the beam diameter can be used. For some quantities used in this International Standard,
the first definition (encircled power [energy]) is more appropriate and easier to use.
The International Organization for Standardization (ISO) draws attention to the fact that it is claimed
that compliance with this document can involve the use of patents concerning the inclusion of negative
noise values in background evaluation of CCD camera images as described in 8.3.2.
ISO takes no position concerning the evidence, validity, and scope of this patent right.
The holder of this patent right (U.S. No. 5,418,562 and 5,440,562, and PCT WO 94/27401) has assured
ISO that they are willing to negotiate licenses under reasonable and non-discriminatory terms and
conditions with applicants throughout the world. In this respect, the statement of the holder of this
patent right is registered with ISO. Information can be obtained from:
Spiricon Inc.
Laser Beam Diagnostics
2600 North Main
Logan, UT 84341
USA
© ISO 2015 – All rights reserved v
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SIST EN ISO 13694:2016
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SIST EN ISO 13694:2016
INTERNATIONAL STANDARD ISO 13694:2015(E)
Optics and photonics — Lasers and laser-related
equipment — Test methods for laser beam power (energy)
density distribution
1 Scope
This International Standard specifies methods by which the measurement of power [energy] density
distribution is made and defines parameters for the characterization of the spatial properties of laser
power [energy] density distribution functions at a given plane.
The methods given in this International Standard are intended to be used for the testing and
characterization of both continuous wave (cw) and pulsed laser beams used in optics and optical
instruments.
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.
ISO 11145, Optics and photonics — Laser and laser-related equipment — Vocabulary and symbols
ISO 11146 (all parts), Lasers and laser-related equipment — Test methods for laser beam widths, divergence
angles and beam propagation ratios
ISO 11554, Optics and photonics — Lasers and laser-related equipment — Test methods for laser beam
power, energy and temporal characteristics
IEC 61040, Power and energy measuring detectors, instruments and equipment for laser radiation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11145 and IEC 61040 and the
following apply.
3.1 Measured quantities
3.1.1
power density distribution
Ex(, yz,)
set of all power densities at location z of a certain CW beam with non-negative values for all transverse
coordinates (x,y)
3.1.1.1
power density
Ex(, yz,)
00
part of the beam power at location z which impinges on the area δA at the location (x , y ) divided by
0 0
the area δ A (δ A→ 0 )
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
3.1.2
energy density distribution
Hx(, yz,)
set of all energy densities at location z of a certain pulsed beam with non-negative values for all
transverse coordinates (x, y)
Hx(, yz,)= Ex(, yz,)dt
∫
3.1.2.1
energy density
Hx(, yz,)
00
〈 pulsed laser beam〉 part of the beam energy (time-integrated power) at location z which impinges on
the area δA at the location (x , y ) divided by the area δ A (δ A→ 0 )
0 0
Hx(, yz,)= Ex(, yz,)dt
00 00
∫
3.1.3
power
Pz()
power in a continuous wave (cw) beam at location z
Pz()= Ex(, yz,)ddxy
∫∫
3.1.4
pulse energy
Qz()
energy in a pulsed beam at location z
Qz()= Hx(, yz,)ddxy
∫∫
3.1.5
maximum power [energy] density
Ez() [Hz() ]
max max
maximum of the spatial power [energy] density distribution functionEx(, yz,) [Hx(, yz,) ] at location z
3.1.6
location of the maximum
(,xy ,)z
maxmax
location of Ez() or Hz() in the xy plane at location z
max max
Note 1 to entry: (,xy ,)z cannot be uniquely defined when measuring with detectors having a high
maxmax
spatial resolution and a relatively small dynamic range.
3.1.7
clip-level power [energy] density
Ez() [Hz() ]
ηCL ηCL
fraction η of the maximum power [energy] density (3.1.5) at location z
Ez()=ηEz()
ηCL max
Hz()=ηHz()
ηCL max
2 © ISO 2015 – All rights reserved
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
01≤<η
Note 1 to entry: Notations E or H and the names threshold power [energy] density, respectively, can be used
ηT ηT
instead of E or H and the names clip-level power [energy] density, respectively, when E or H is just greater
ηCL ηCL ηCL ηCL
than detector background noise peaks at the time of measurement. 8.3 describes background noise subtraction
methods used to determine detector zero levels. Circumstances such as the application involved, distribution type,
detector sensitivity, linearity, saturation, baseline, offset level, etc., can also dictate the choice of η.
Note 2 to entry: When no confusion is possible, the explicit dependence on z is dropped in the text description
using some quantities, but not in the definitions or in the equations involving the quantities.
3.2 Characterizing parameters
3.2.1
clip-level power [energy]
Pz() [Qz() ]
η η
Pz() [Qz() ] evaluated by summing only over locations (x,y) for which Ex(, yz,)> Ez()
ηCL
[(Hx,,yz)(> Hz)]
ηCL
3.2.2
fractional power [energy]
fz()
η
fraction of the clip-level power [energy] (3.2.1) for a given η to the total power [energy] in the distribution
at location z
Pz()
η
fz()= for cw-beams;
η
Pz()
Qz()
η
fz()= for pulsed beams;
η
Qz()
01≤≤fz()
η
3.2.3
centre of gravity
centroid position
xz(),(yz)
()
first-order moments of a power[energy] distribution at location z
Note 1 to entry: For a more detailed definition, see ISO 11145 and ISO 11146.
3.2.4
beam widths
dz() , dz()
σx σ y
widths dz() and dz() of the beam in the x and y directions at z, equal to four times the square root
σx σ y
of the second linear moments of the power [energy] density distribution about the centroid
Note 1 to entry: For a more detailed definition, see ISO 11145 and ISO 11146.
Note 2 to entry: The provisions of ISO 11146 apply to definitions and measurements of:
a) second moment beam widths d and d ;
σx σy
b) beam widths d and d in terms of the smallest centred slit width that transmits u % of the total power
x,u y,u
[energy] density (usually u = 86,5);
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
c) scanning narrow slit measurements of beam widths d and d in terms of the separation between positions
x,s y,s
where the transmitted power density (3.1.1.1) is reduced to 0,135 E ;
p,
d) measurements of beam widths d and d in terms of the separation between 0,84 P and 0,16 P obscuration
x,k y,k
positions of a movable knife-edge, where P is the maximum, unobstructed power recorded by the large area
detector behind the knife-edge plane;
e) correlation factors which relate these different definitions and methods for measuring beam widths.
3.2.5
beam ellipticity
ε()z
parameter for quantifying the circularity or squareness of a power [energy] density distribution at z
dz()
σ y
ε()z =
dz()
σx
Note 1 to entry: The direction of x is chosen to be along the major axis of the distribution so dd≥ .
σσxy
Note 2 to entry: If ε≥08, 7 , elliptical distributions can be regarded as circular. In case of a rectangular beam
profile, ellipticity is often referred to as aspect ratio.
Note 3 to entry: Technically identical with ISO 11145 and ISO 11146-1.
3.2.6
beam cross-sectional area
Az()
σ
2
Ad=π /4 for beam with circular cross-section;
σσ
Ad= π / 4 d for beam with elliptical cross-section.
()
σσxyσ
3.2.7
clip-level irradiation area
i
Az()
η
irradiation area at location z for which the power [energy] density exceeds the clip-level power [energy]
density (3.1.7)
Note 1 to entry: To allow for distributions of all forms, for example hollow “donut” types, the clip-level irradiation
area is not defined in terms of the beam widths (3.2.4) d or d .
σx σy
Note 2 to entry: See clip-level power [energy] density (3.1.7).
3.2.8
clip-level average power [energy] density
Ez() , [Hz() ]
ηave ηave
spatially averaged power [energy] density of the distribution at location z, defined as the weighted mean:
Pz()
η
Ez()= for cw-beams;
ηave
i
Az()
η
Qz()
η
Hz()= for pulsed beams
ηave
i
Az()
η
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
Note 1 to entry: Ez() and Ez() (see 3.1.7) refer to different parameters.
ηave ηCL
3.2.9
flatness factor
Fz()
η
ratio of the clip-level average power [energy] density to the maximum power [energy] density of the
distribution at location z
Ez()
ηave
Fz()= for cw-beams;
η
Ez()
max
Hz()
ηave
Fz()= for pulsed beams
η
Hz()
max
01<≤F
η
Note 1 to entry: For a power [energy] density distribution having a perfectly flat top F = 1 .
η
3.2.10
beam uniformity
Uz()
η
normalized root mean square (r.m.s.) deviation of power [energy] density distribution from its clip-
level average value at location z
2
11
Uz() = Ex,,yz −Ez() ddxy for cw-beams;
()
η ηave
∫∫
i
Ez()
Az()
ηave
η
2
11
Uz() = Hx,,yz −Hz() ddxy for pulsed beams
()
η ∫∫ ηave
i
Hz()
Az()
ηave
η
Note 1 to entry: U = 0 indicates a completely uniform distribution having a profile with a flat top and vertical
η
edges, U is expressed as either a fraction or a percentage.
η
Note 2 to entry: By using integration over the beam area between set clip-level limits, this definition allows for
arbitrarily shaped beam footprints to be quantified in terms of their uniformity. Hence uniformity measurements
can be made for different fractions of the total beam power [energy] without specifically defining a windowing
aperture or referring to the shape or size of the distribution. Thus using the formulae in 3.2.2 and 3.2.10,
statements such as: “Using a setting η = 0,3, 85 % of the beam power [energy] was found to have a uniformity of
±4,5 % r.m.s. from its mean value at z” can be made without reference to the distribution shape, size, etc.
3.2.11
plateau uniformity
Uz()
p
〈 for distributions having a nearly flat-top profile〉
ΔE
FWHM
Uz()= for cw-beams;
p
E
max
ΔH
FWHM
Uz()= for pulsed beams
p
H
max
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
where ΔE [ΔH ] is the full-width at half-maximum (FWHM) of the peak near E [H ]
FWHM FWHM max max
of the power [energy] density histogram N(E ) [N(H )], i.e. the number of (x, y) locations at
i i
which a given power [energy] density E [H ] is recorded
i i
Note 1 to entry: 01<
p p
3.2.12
edge steepness
sz()
ηε,
i i
normalized difference between clip-level irradiation areas (3.2.7) Az() and Az() with clip-level power
η ε
[energy] density (3.1.7) values above η E (z) [η H (z)] and above ε E (z) [ε H (z)] respectively
max max max max
ii
Az()− Az()
ηε
sz()=
ηε,
i
Az()
η
01≤<ηε <
01<
ηε,
Note 1 to entry: sz()→ 0 as the edges of the distribution become more vertical.
ηε,
Note 2 to entry: η is typically set to 10 %, ε to 90 % of the maximum power (energy) density.
i
Note 3 to entry: Parameters E , E , P , A , F , and U , are illustrated in Figure 1 for a uniform power density
max ηave η η η
η
distribution (3.1.1) in one dimension.
Figure 1 — Illustration for a uniform power density distribution E(x) in one dimension
4 Coordinate system
The x, y, z Cartesian axes define the orthogonal space directions in the beam axes system. The x and
y axes are transverse to the beam and define the transverse plane. The beam propagates along the
z axis. The origin of the z axis is in a reference xy plane defined by laser manufacturer, e.g. the front of
6 © ISO 2015 – All rights reserved
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SIST EN ISO 13694:2016
ISO 13694:2015(E)
the laser enclosure. For elliptical beams, the principal axes of the distribution coincide with the x and y
axes, respectively. In cases for which the principal axes of the distribution are rotated with respect to
the laboratory coordinate system, the provisions of ISO 11146 describing coordinate rotation through
an az
...
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