Overview
ISO 15367-2:2005 - Lasers and laser-related equipment: Test methods for determination of the shape of a laser beam wavefront - Part 2: Shack‑Hartmann sensors describes standardized methods to measure and evaluate the wavefront distribution in a transverse plane of a laser beam using Hartmann or Shack‑Hartmann wavefront sensors. The standard applies to fully coherent and partially coherent beams, including astigmatic beams, for both pulsed and continuous operation. It defines procedures for data acquisition, centroid evaluation, and reliable zonal (direct numerical) and modal (e.g., Zernike) wavefront reconstruction, plus guidelines for estimating measurement uncertainty.
Key topics and requirements
- Measurement principle: subdivision of the beam into beamlets via a pinhole (Hartmann) or lenslet array (Shack‑Hartmann); centroid detection on a position‑sensitive detector (CCD, quadcells) yields local wavefront gradients.
- Detector arrangement: specifications for lenslet/pinhole arrays, sub‑aperture spacing, and detector spacing (L, often set to lenslet focal length f).
- Data acquisition & processing: background subtraction, centroid determination, partitioning detector into sub‑apertures, and recording instrument details (array size, spacing, model).
- Wavefront reconstruction: zonal (direct numerical integration) and modal reconstruction methods; guidance on implementation and annex material (Zernike polynomials) for modal representation.
- Uncertainty analysis: treatment of statistical measurement errors, environmental effects, data acquisition deficiencies, and geometrical misalignment - with methods to estimate and report combined uncertainty.
- Calibration and test report: requirements for calibration procedures and mandatory information to include in the test report.
Practical applications and users
ISO 15367-2:2005 is intended for professionals who need standardized, traceable wavefront measurements, including:
- Optical and laser system designers (resonator design, beam delivery)
- Metrology and test laboratories performing laser beam characterization
- Adaptive optics engineers optimizing beam focusability
- Manufacturers of Shack‑Hartmann sensors and beam diagnostic equipment
- Industrial laser users monitoring thermal lensing, alignment, or “at‑wavelength” optics testing
Practical uses include beam quality assessment, on‑line resonator alignment, adaptive optics control, evaluation of optical components using modal decomposition (Zernike analysis), and comparison of instruments under a common standard.
Related standards
- ISO 15367‑1:2003 - Terminology and fundamental aspects (defines wavefront parameters referenced here)
- ISO 11145 - Vocabulary and symbols for lasers
- ISO 13694 - Laser beam power (energy) density distribution test methods
Keywords: ISO 15367-2:2005, Shack‑Hartmann sensors, wavefront measurement, laser beam wavefront, Hartmann sensor, wavefront reconstruction, Zernike polynomials, beam diagnostics, laser metrology.
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