ISO 12005:2022

Overview

ISO 12005:2022 - Lasers and laser-related equipment - Test methods for laser beam parameters - Polarization - specifies a practical, quick and simple method to determine the polarization state and, where possible, the degree of polarization of continuous-wave (cw) lasers. The method also applies to repetitively pulsed lasers whose electric-field orientation is stable pulse-to-pulse. The 2022 (third) edition updates definitions and measurement guidance to support testing of collimated, highly divergent and large-aperture beams.

Key topics and technical requirements

• Measurement principle: Initial test uses a rotatable linear polarizer to record maximum and minimum transmitted power while varying polarizer angle. If not purely linear, a quarter-wave plate plus polarizer is used to check for elliptical or circular polarization.
• Equipment and arrangement:
  • Detector requirements follow ISO 11554 (linearity, wavelength response, calibration); only relative power/energy measurements are necessary for polarization analysis.
  • For highly divergent beams, insert collimating optics or a telescope before the polarizer.
  • For large-aperture beams, measure non-overlapping sub-apertures or use imaging detectors (CCD/CMOS) to verify spatial uniformity.
  • Use of optical attenuators and confirmation of damage thresholds for optics and detectors is required.
• Quantities defined:
  • Degree of polarization and degree of linear polarization definitions and how to compute them from measured max/min transmitted powers (or energies).
  • Extinction ratio and polarization ratio metrics for assessing polarizer quality and beam linearity.
• Analysis & reporting: Procedures for result analysis and required content of a test report are specified. Annex A provides background on Stokes parameters and full description of polarization for more comprehensive characterization (not required for the basic method).

Practical applications and users

ISO 12005:2022 is intended for:

• Laser manufacturers and test laboratories performing routine polarization checks.
• Optical engineers coupling lasers into polarization-dependent devices (e.g., polarization-maintaining fibres, polarizing optics).
• R&D and quality assurance teams evaluating beam quality for sensors, imaging, telecommunications and metrology where polarization affects performance.
• Users needing rapid polarization assessment for divergent or large-aperture laser beams where simple, minimum-equipment tests are preferred.

Practical benefits include fast verification of polarization state before fiber coupling or integration with polarization-sensitive systems, and standardized reporting for procurement and compliance.

Related standards

• ISO 11145 - Vocabulary and symbols (optics and photonics)
• ISO 11554 - Test methods for laser beam power, energy and temporal characteristics (detector guidance)
• CIE 059-1984 - Instrument polarization definitions

Keywords: ISO 12005:2022, laser polarization, polarization measurement, degree of polarization, linear polarizer, quarter-wave plate, extinction ratio, polarization maintaining fibres, divergent beams.