Overview
ISO 13694:2018 specifies standardized test methods for measuring the spatial power (energy) density distribution of laser beams. It defines terms, symbols and measurement requirements for characterizing the irradiance (cw lasers) and time‑integrated irradiance (energy density for pulsed lasers) in a plane perpendicular to propagation. The standard covers practical measurement arrangements, detector systems, calibration, data recording and noise correction, evaluation and required content for the test report.
Keywords: ISO 13694:2018, laser beam power density distribution, energy density distribution, beam characterization, laser testing methods.
Key Topics and Requirements
- Definitions and coordinate system for describing power density E(x,y,z) and energy density H(x,y,z).
- Measurement of both continuous wave (cw) and pulsed laser beams (pulsed beams: time‑integrated energy density is typically measured).
- Accepted measurement techniques: camera arrays (1D/2D), apertures, pinholes, slits, and knife edges.
- Characterizing parameters derived from measured distributions, including:
- Beam centroid (first moments)
- Beam widths (second‑moment definitions and alternative width measures)
- Beam ellipticity
- Beam cross‑sectional area
- Clip‑level power/energy and fractional power/energy
- Detailed requirements for test setup: detector system, beam‑forming optics, optical attenuators and beam splitters, environmental control and preparation.
- Procedures for detector spatial and power (energy) calibration, data recording, background/noise correction and evaluation.
- Test report contents and informative annex with example report structure.
Applications and Who Uses It
ISO 13694:2018 is used where accurate spatial characterization of laser irradiance is required:
- Laser and optical instrument manufacturers for product verification and quality control.
- Calibration and test laboratories validating beam profiles and system performance.
- Optical designers and researchers assessing beam propagation and mode quality (inputs for beam propagation ratio M2 measurements).
- Medical device developers, material processing engineers and safety officers performing exposure assessments or optimizing process parameters.
- OEM integrators and system installers verifying alignment and beam shaping.
Practical benefits: consistent, traceable beam-profile measurements for specification compliance, performance troubleshooting, and reproducible data for R&D or regulatory submissions.
Related Standards
- ISO 11145 - Vocabulary and symbols for lasers and laser‑related equipment
- ISO 11146‑1 - Test methods for beam widths, divergence and beam propagation ratio (M2)
- ISO 11554 - Test methods for laser power, energy and temporal characteristics
- IEC 61040 - Power and energy measuring detectors and instruments
Using ISO 13694:2018 ensures standardized, comparable laser beam profile data across testing labs and industry applications.