ISO/TC 172/SC 9/WG 1 - Terminology and test methods for electro-optical systems

This document specifies procedures for the absorption measurement and high spatial-resolution two-dimensional or three-dimensional absorption mapping of optical laser components, and upon calibration, the measurement of absolute absorptance of laser optics. The methods given in this document are intended to be used for the two-dimensional or three-dimensional absorption mapping of optical laser components, that is, measurement of absorption as a function of position, as well as absorption/absorptance measurement and mapping of laser optics used in high-power/high-energy laser systems.

This document specifies procedures for the determination of the total scattering by coated and uncoated optical surfaces. Procedures are given for measuring the contributions of the forward scattering or backward scattering to the total scattering of an optical component. This document applies to coated and uncoated optical components with optical surfaces that have a radius of curvature of more than 10 m. Measurement wavelengths covered by this document range from the ultraviolet above 250 nm to the infrared spectral region below 15 µm. For measurements in the deep ultraviolet between 190 nm to 250 nm, specific methods are considered and are described. Generally, optical scattering is considered as neglectable for wavelengths above 15 µm.

This document specifies a method, which is a relatively quick and simple method with minimum equipment, for determining the polarization status and, whenever possible, the degree of polarization of the beam from a continuous wave (cw) laser. It can also be applied to repetitively pulsed lasers, if their electric field vector orientation does not change from pulse to pulse. This document also specifies the method for determining the direction of the electric-field vector oscillation in the case of (completely or partially) linearly polarized laser beams. It is assumed that the laser radiation is quasimonochromatic and sufficiently stable for the purpose of the measurement. This document is applicable to radiation that has uniform polarization over its cross-sectional area. The knowledge of the polarization status can be very important for some applications of lasers with a high divergence angle, for instance when the beam of such a laser shall be coupled with polarization dependent devices (e.g. polarization maintaining fibres). This document is applicable not only for a narrow and almost collimated laser beam but also for highly divergent beams as well as for beams with large apertures.

This document covers terms, definitions, and a verification procedure to characterize the ability of laser lenses to collimate divergent laser beams and to focus collimated laser to small spot sizes. The aim of this document is to give users reliable information on the applicability of laser lenses in the field of beam forming.

This document specifies methods for measuring beam widths (diameter), divergence angles and beam propagation ratios of laser beams. This document is only applicable for stigmatic and simple astigmatic beams. If the type of the beam is unknown, and for general astigmatic beams, ISO 11146‑2 is applicable.

This document specifies methods for measuring beam widths (diameter), divergence angles and beam propagation ratios of laser beams. This document is applicable to general astigmatic beams or unknown types of beams. For stigmatic and simple astigmatic beams, ISO 11146‑1 is applicable. Within this document, the description of laser beams is accomplished by means of the second order moments of the Wigner distribution rather than physical quantities such as beam widths and divergence angles. However, these physical quantities are closely related to the second order moments of the Wigner distribution. In ISO/TR 11146‑3, formulae are given to calculate all relevant physical quantities from the measured second order moments.

This document specifies measurement procedures for the precise determination of the high reflectance or high transmittance (>99 %) of optical laser components. The methods given in this document are intended to be used for the testing and characterization of high reflectance of both concave and plane mirrors or high transmittance of plane windows used in laser systems and laser-based instruments. The reflectance of convex mirrors or transmittance of positive or negative lenses can also be tested by taking into consideration the radius of curvature of the mirror surface or the focal length of the lens. This document is complementary to ISO 15368 which specifies the measurement procedures for the determination of reflectance and transmittance of optical components with spectrophotometry. ISO 15368 is applicable to the measurements of reflectance and transmittance in the range from 0 % to 100 % with a typical accuracy of ±0,3 %, and is therefore not applicable to the precise measurements of reflectance and transmittance higher than 99,9 %.

This document describes procedures for the determination of the angle resolved scattering by optical components such as coated or uncoated optical elements, photonic structures, and materials that can be transparent, translucent, or opaque. It comprises scattering into the scattering sphere around the specimen usually separated into the backward and forward hemispheres. The procedures apply to wavelengths of radiation ranging from 5 nm in the extreme ultraviolet to 15 µm in the infrared spectral ranges.

This document specifies procedures and techniques for obtaining comparable values for the absorptance of optical laser components.

This document 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 document 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. This document 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.

This document defines basic terms, symbols, and units of measurement for the field of laser technology in order to unify the terminology and to arrive at clear definitions and reproducible tests of beam parameters and laser-oriented product properties. NOTE The laser hierarchical vocabulary laid down in this document differs from that given in IEC 60825?1. ISO and IEC have discussed this difference and agree that it reflects the different purposes for which the two standards serve. For more details, see informative Annex A.

This document describes methods of measuring temperature and injected current dependence of lasing wavelengths, and lasing spectral line width in relation to semiconductor lasers for sensing applications. This document is applicable to all kinds of semiconductor lasers, such as edge-emitting type and vertical cavity surface emitting type lasers, bulk-type and (strained) quantum well lasers, and quantum cascade lasers, used for optical sensing in e.g. industrial, medical and agricultural fields.

ISO 11554:2017 specifies test methods for determining the power and energy of continuous wave and pulsed laser beams, as well as their temporal characteristics of pulse shape, pulse duration and pulse repetition rate. Test and evaluation methods are also given for the power stability of cw-lasers, energy stability of pulsed lasers and pulse duration stability. The test methods given in this document are used for the testing and characterization of lasers.

ISO/TR 20811:2017 describes the setup, test procedure and analysis of measured data for investigation of laser-induced molecular contamination (LIMC) for space and vacuum applications. LIMC is the formation of depositions on optical surfaces due to interaction of intense light radiation with outgassing molecules especially from organic materials. It is a phenomenon of molecular contamination and it is distinguished from particle contamination, which can occur during manufacturing, assembly, integration or test of the optical components. Formation of laser-induced depositions can lead to deterioration of the performance of an optical system. Phase distortion, scattering and absorption can be increased by LIMC. LIMC is of particular relevance, if a laser system is operated in vacuum at short wavelength and short pulse duration. In such a case, even small partial pressure of contamination material in the range of 10−5 hPa could have strong negative impact on optical performance. It was also shown that the laser-induced damage threshold could be reduced by a factor of 10 and more if laser-induced depositions are involved. Laser-induced molecular contamination and laser-induced damage are both phenomena, for which the interaction of laser radiation with optical surfaces plays a major role, in case of LIMC with additional molecular contamination. Therefore, ISO/TR 20811:2017 is treated in relation to ISO 21254 (all parts) which specifies the test methods for the determination of laser-induced damage thresholds. This method was derived to evaluate qualitatively, whether the material under investigation causes deposits on optical surfaces in a low-pressure environment in the presence of high-energy nanosecond pulsed laser irradiation at a wavelength of 355 nm. Due to the nature of photochemical surface reactions, this result cannot be directly transferred to scenarios where the properties of the irradiation are altered (especially wavelength, repetition rate, pulse duration, etc.). Due to the non-linear growth of the laser-induced contamination and its detection methods, this technique does not provide quantitative means to evaluate the deposit and, therefore, it should be seen as a means to compare materials relatively with respect to their laser-induced contamination behaviour. Furthermore, it is out of the scope of this method to select representative quantities of contamination materials - representative with respect to the material partial pressure present in the vicinity of the optical surface in a real laser system. This is carefully derived with other methods and is a mandatory parameter to be fixed before applying this method.

ISO 15367-2:2005 specifies methods for measurement and evaluation of the wavefront distribution function in a transverse plane of a laser beam utilizing Hartmann or Shack-Hartmann wavefront sensors. ISO 15367-2:2005 is applicable to fully coherent, partially coherent and general astigmatic laser beams, both for pulsed and continuous operation. Furthermore, reliable numerical methods for both zonal and modal reconstruction of the two-dimensional wavefront distribution together with their uncertainty are described. The knowledge of the wavefront distribution enables the determination of several wavefront parameters that are defined in ISO 15367-1.

ISO 13695:2004 specifies methods by which the spectral characteristics such as wavelength, bandwidth, spectral distribution and wavelength stability of a laser beam can be measured. ISO 13695:2004 is applicable to both continuous wave (cw) and pulsed laser beams. The dependence of the spectral characteristics of a laser on its operating conditions may also be important.

ISO/TR 11146-3:2004 specifies methods for measuring beam widths (diameter), divergence angles and beam propagation ratios of laser beams in support of ISO 11146-1. It provides the theoretical description of laser beam characterization based on the second-order moments of the Wigner distribution, including geometrical and intrinsic beam characterization, and offers important details for proper background subtraction methods recommendable for matrix detectors such as CCD cameras. It also presents alternative methods for the characterization of stigmatic or simple astigmatic beams that are applicable where matrix detectors are unavailable or deliver unsatisfying results.

ISO 15367-1:2003 specifies methods for the measurement of the topography of the wavefront of a laser beam by measurement and interpretation of the spatial distribution of the phase of that wavefront across a plane approximately perpendicular to its direction of propagation. Requirements are given for the measurement and analysis of phase distribution data to provide quantitative wavefront parameters and their uncertainty in a test report. The methods described in ISO 15367-1:2003 are applicable to the testing and characterization of a wide range of beam types from both continuous wave and pulsed lasers. Definitions of parameters describing wavefront deformations are given together with methods for the determination of those parameters from phase distribution measurements.

ISO 17526:2003 covers terms and definitions as well as test methods and evaluation procedures to characterize, estimate and predict the longterm behaviour of various types of lasers. It defines terms for the lifetime of lasers and specifies test procedures and fundamental aspects for the determination of lifetime. It applies for all types of lasers for which lifetime is a critical issue, including diode lasers except those used in telecommunications.

ISO 11670:2003 specifies methods for determining laser beam positional as well as angular stability. The test methods given in ISO 11670:2003 are intended to be used for the testing and characterization of lasers.

ISO 11145:2016 defines basic terms, symbols, and units of measurement for the field of laser technology in order to unify the terminology and to arrive at clear definitions and reproducible tests of beam parameters and laser-oriented product properties. NOTE The laser hierarchical vocabulary laid down in this International Standard differs from that given in IEC 60825?1. ISO and IEC have discussed this difference and agree that it reflects the different purposes for which the two standards serve. For more details, see informative Annex A.

ISO 13694:2015 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.

ISO/TS 17915:2013 describes methods of measuring temperature, injected current dependence and lasing spectral line width in relation to semiconductor lasers for sensing applications. ISO/TS 17915:2013 is applicable to all kinds of semiconductor lasers, such as edge-emitting type and vertical cavity surface emitting type lasers, bulk-type and (strained) quantum well lasers, and quantum cascade lasers, used for optical sensing in e.g. industrial, medical and agricultural fields. ISO/TS 17915:2013 is an application of ISO 13695, in which the physical bases are explained.

ISO 11145:2006 defines basic terms, symbols and units of measurement for the field of laser technology in order to unify the terminology and to arrive at clear definitions and reproducible tests of beam parameters and laser-oriented product properties.

ISO 11554:2006 specifies test methods for determining the power and energy of continuous-wave and pulsed laser beams, as well as their temporal characteristics of pulse shape, pulse duration and pulse repetition rate. Test and evaluation methods are also given for the power stability of cw-lasers, energy stability of pulsed lasers and pulse duration stability. The test methods given in ISO 11554:2006 are used for the testing and characterization of lasers.

ISO 11146-2:2005 specifies methods for measuring beam widths (diameter), divergence angles and beam propagation ratios of laser beams. ISO 11146-2:2005 is applicable to general astigmatic beams or unknown types of beams. For stigmatic and simple astigmatic beams, ISO 11146-1 is applicable. Within ISO 11146-2:2005, the description of laser beams is accomplished by means of the second order moments of the Wigner distribution rather than physical quantities such as beam widths and divergence angles. However these physical quantities are closely related to the second order moments of the Wigner distribution. In ISO/TR 11146-3, formulae are given to calculate all relevant physical quantities from the measured second order moments.

ISO 11146-1:2005 specifies methods for measuring beam widths (diameter), divergence angles and beam propagation ratios of laser beams. ISO 11146-1:2005 is only applicable for stigmatic and simple astigmatic beams. If the type of the beam is unknown and for general astigmatic beams ISO 11146-2 is applicable.

ISO 11554:2003 specifies test methods for determining the power and energy of continuous-wave and pulsed laser beams, as well as their temporal characteristics of pulse shape, pulse duration and pulse repetition rate. Test and evaluation methods are also given for the power stability of cw-lasers, energy stability of pulsed lasers and pulse duration stability.

ISO 12005:2003 specifies a method for determining the polarization status and, whenever possible, the degree of polarization of the beam from a continuous wave (cw) laser. It can also be applied to repetitively pulsed lasers, if their electric field vector orientation does not change from pulse to pulse. ISO 12005:2003 also specifies the method for determining the direction of the plane of oscillation in the case of linearly polarized (totally or partially) laser beams. It is assumed that the laser radiation is quasi-monochromatic and sufficiently stable for the purpose of the measurement. The knowledge of the polarization status can be very important for some applications of lasers with a high divergence angle, for instance when the beam of such a laser shall be coupled with polarization dependent devices (e.g. polarization maintaining fibres). ISO 12005:2003 also specifies a method for the determination of the state of polarization of highly divergent laser beams, as well as for the measurement of beams with large apertures.