ISO 13142-2021 PDF

Full title and description

Optics and photonics — Lasers and laser-related equipment — Cavity ring-down method for high-reflectance and high-transmittance measurements. This International Standard specifies the cavity ring-down measurement procedures and related guidance for precise determination of very high reflectance and transmittance of laser optical components.

Abstract

This document provides measurement procedures for the precise determination of high reflectance and high transmittance (typically >99 %) of optical laser components. The methods cover testing and characterization of high-reflectance mirrors (plane and concave) and high-transmittance plane windows used in laser systems; adaptations for convex mirrors and lenses are addressed by taking curvature or focal length into account. The standard is intended for measurements where conventional spectrophotometry is not sufficiently precise (e.g., for reflectance/transmittance approaching or exceeding 99.9 %).

General information

• Status: Published.
• Publication date: June 2021 (Edition 2).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 31.260 (Optics and photonics).
• Edition / version: Edition 2 (2021).
• Number of pages: 17.

Scope

Specifies cavity ring-down based measurement procedures and associated test arrangements for the precise determination of very high reflectance and very high transmittance of laser optical components. Applies to plane and concave mirrors and to plane windows; measurements on convex mirrors or lenses are included where appropriate corrections for radius of curvature or focal length are applied. The methods are complementary to spectrophotometric procedures (for example ISO 15368) and are specifically intended when spectrophotometry cannot provide the required precision at reflectance/transmittance levels approaching unity.

Key topics and requirements

• Principle and implementation of the cavity ring-down (CRD) measurement technique for high-reflectance/high-transmittance optics.
• Recommended experimental arrangements and optical layouts for plane and concave mirror measurements and for plane-window transmittance tests.
• Sample preparation, mounting and alignment practices required to minimise systematic errors.
• Calibration and reference procedures, including treatment of cavity losses and coupling efficiency.
• Procedures for uncertainty evaluation and reporting of measured reflectance/transmittance values at very high levels (>99 %).
• Corrections and considerations for curved optics (radius of curvature, focal length) when testing non‑planar components.
• Limitations and applicability: not intended for diffuse reflectance/transmittance measurements; complementary to spectrophotometric methods for routine spectral measurements.

Typical use and users

Used by optical component manufacturers, laser-system integrators, calibration and metrology laboratories, research institutes and quality/verification teams involved in high-performance laser optics. Typical applications include acceptance testing of high-reflectance mirrors for laser resonators, quality assurance of anti-reflection or high-transmission coatings on windows and substrates, and research measurements where very small deviations from unity transmittance/reflectance must be quantified.

Related standards

Notable related documents include ISO 15368 (Measurement of reflectance of plane surfaces and transmittance of plane parallel elements), which covers spectrophotometric methods for reflectance and transmittance and is complementary to the CRD methods in ISO 13142; and ISO 11145 (vocabulary and symbols for lasers and laser-related equipment) for consistent terminology in laser metrology. ISO 13142:2021 replaces the earlier 2015 edition.

Keywords

cavity ring‑down, CRD, reflectance measurement, transmittance measurement, high reflectance, high transmittance, laser optics, optical coatings, metrology, uncertainty evaluation, optical mirrors, plane windows.

FAQ

Q: What is this standard?

A: ISO 13142:2021 is an International Standard that specifies cavity ring-down measurement procedures for precise determination of very high (>99 %) reflectance and transmittance of laser optical components.

Q: What does it cover?

A: It covers the CRD measurement principle, recommended test arrangements, calibration and alignment procedures, uncertainty evaluation, and specific guidance for testing plane and concave mirrors and plane windows; it also discusses adaptations for curved optics. It is intended for conditions where spectrophotometry does not achieve the required precision.

Q: Who typically uses it?

A: Optical manufacturers, laser-system designers and integrators, metrology and calibration laboratories, research institutions and QA groups responsible for high-performance laser optics and coatings.

Q: Is it current or superseded?

A: Current — ISO 13142:2021 (Edition 2) is the published version and it supersedes ISO 13142:2015.

Q: Is it part of a series?

A: It sits within ISO’s optics and photonics portfolio (ICS 31.260) and is closely related to other reflectance/transmittance measurement standards such as ISO 15368; it was developed under ISO/TC 172 (optics and photonics) subcommittees.

Q: What are the key keywords?

A: cavity ring‑down, reflectance, transmittance, high-reflectance, high-transmittance, laser optics, optical measurement, metrology, uncertainty.