ISO 13695:2024

Overview

ISO 13695:2024 - Optics and photonics - Lasers and laser-related equipment - Test methods for the spectral characteristics of lasers - specifies standardized methods to measure and report the spectral characteristics of laser emission. The standard covers measurement of wavelength, bandwidth (RMS, FWHM), spectral distribution, and wavelength stability for both continuous wave (cw) and pulsed lasers. It also addresses how spectral properties depend on operating conditions and defines the terminology and symbols used in testing and reporting.

Key topics and requirements

• Scope and definitions: Key parameters (peak-emission wavelength λp, weighted-average λg, RMS spectral bandwidth Δλ, FWHM Δλ_H, etc.) and how to select integration limits for spectral metrics.
• Traceability: Requirements for metrological traceability of wavelength measurements and calibration practices.
• Measurement accuracy classes: Guidance for low, medium, and high accuracy measurements, with recommended procedures and equipment selection matched to the required uncertainty.
• Equipment and methods:
  • Low-resolution measurements (general-purpose spectrometers/monochromators).
  • Higher-resolution techniques using grating spectrometers, interferometers (e.g., Fabry–Pérot), and photoelectric mixing / heterodyne methods for high-precision frequency/wavelength determination.
• Environmental corrections: Measurement in air versus vacuum; treatment of air refractive index and standard-air reporting (see Annex A).
• Wavelength stability: Procedures to evaluate dependence of wavelength on operating conditions and stability for single-frequency lasers.
• Test reporting: Standardized content for test reports to ensure consistent documentation of methods, conditions, uncertainties and results.
• Informative annexes: Criteria for choosing and calibrating grating monochromators and Fabry–Pérot interferometers (Annexes B and C).

Practical applications and users

ISO 13695:2024 is intended for:

• Laser manufacturers verifying product spectral performance.
• Calibration and testing laboratories establishing traceable wavelength measurements.
• Metrologists and QA teams ensuring compliance with spectral specifications.
• System integrators and OEMs in photonics, telecommunications, lithography, interferometry, spectroscopy, medical devices and precision manufacturing who require documented spectral data.
• R&D groups characterizing new laser sources and measuring wavelength stability under varying operating conditions.

Adopting ISO 13695:2024 helps ensure reliable, comparable spectral measurement results and supports quality assurance, product specification, regulatory compliance and procurement decisions.

Related standards

• ISO 11145 - Optics and photonics: Vocabulary and symbols
• ISO/IEC Guide 99 (VIM) - Metrology terminology
• IEC 60747-5-1 - Optoelectronic device definitions

Keywords: ISO 13695:2024, spectral characteristics of lasers, wavelength measurement, spectral bandwidth, FWHM, interferometer, grating spectrometer, wavelength stability, laser testing standard.