Overview
EN ISO 11670:2003 - “Lasers and laser-related equipment - Test methods for laser beam parameters - Beam positional stability” - defines standardized methods to measure and characterize the positional and angular stability of laser beams. Published by CEN/ISO, this standard presents terminology, coordinate systems, measurement principles and test procedures intended for laboratory testing and product characterization of lasers and laser-related equipment.
Key topics and requirements
- Scope & purpose: Methods for determining beam positional stability and beam angular stability for testing and characterization of lasers.
- Definitions: Precise terms such as centroid (beam centre), beam axis, transverse displacement, angular movement, pivot, beam positional movement, and beam stability parameter product.
- Quantitative measures:
- Beam angular stability (δα) is defined as twice the standard deviation of measured angular movement.
- Beam positional stability (∆(z)) is defined as four times the standard deviation of measured positional movement at plane z.
- Relative stability metrics normalize stability by divergence angle or beam diameter.
- Coordinate systems: Guidance on beam-axis and laboratory coordinate systems and identification of principal axes when beam movement is directional.
- Test procedures & equipment:
- Measurement arrangement, detection system, beam-forming optics, optical attenuators, beam splitters, focusing elements and calibration requirements.
- Environmental control during tests (temperature, mechanical stability, etc.).
- Time-based stability categories: short-term (1 s), medium-term (1 min), long-term (1 h).
- Evaluation & reporting: Procedures for data evaluation, propagation of beam stability, decoupling short- and long-term fluctuations and required test-report content.
- Annexes: Informative Annex A (propagation of absolute beam stability) and Annex B (decoupling short- and long-term fluctuations).
Applications and who uses it
EN ISO 11670:2003 is used by:
- Laser manufacturers for product specification and quality control.
- Test laboratories and certification bodies performing compliance testing.
- Optical and systems engineers designing pointing/stability-critical systems (free-space communications, LIDAR, directed-energy, medical lasers, material processing and precision alignment).
- R&D teams evaluating performance changes, warm-up behaviour (beam positional change from cold start) and beam steering stability.
Practical uses include verifying pointing accuracy, quantifying jitter/beam wander, and comparing relative stability across laser models.
Related standards
- ISO 11145:2001 - Vocabulary and symbols for lasers
- ISO 11146:1999 - Test methods for beam widths, divergence and propagation factor
- IEC 61040:1990 - Power and energy measuring detectors for laser radiation
Keywords: EN ISO 11670:2003, beam positional stability, laser beam parameters, beam angular stability, laser testing, measurement methods, beam stability parameter product.
