IEC 61280-1-3:2010

Overview

IEC 61280-1-3:2010 defines measurement definitions and procedures for central wavelength and spectral width properties of optical spectra in fibre optic communication subsystems. It covers test methods for optical transmitters and light sources used in system construction and maintenance, including measurements while transmitters are modulated. The second edition updates the first (1998) to reflect advances in laser technology and adds a modified second method for modern instrumentation.

Key technical topics and requirements

• Scope of measurement
  • Central wavelength definitions: centre wavelength, centroidal wavelength, peak wavelength.
  • Spectral width definitions: RMS spectral width, n-dB-down width, full-width half-maximum (FWHM).
  • Additional characteristic: side-mode suppression ratio (SMSR) for nominally single-longitudinal-mode (SLM) lasers.
• Test methods
  • Method A: Uses high-sample-count optical spectrum analyzers (OSA) to analyze dense spectra.
  • Method B: Legacy method using discrete wavelength points; retained for compatibility with earlier instrumentation.
• Apparatus and calibration
  • Requires a calibrated optical spectrum analyzer (OSA). Calibration per IEC 62129 is mandatory.
  • Recommended OSA capabilities: for LEDs, ~1 nm or better resolution and >200 nm range; for lasers (WDM applications) ~0.1 nm or better resolution. OSA sensitivity must capture at least –20 dB from peak; higher dynamic range needed for SMSR.
• Test setup and samples
  • Test cords typically 2–5 m long, matching intended cable plant; single-mode cords require specific loop arrangements to reject cladding modes.
  • Measurements usually performed with the transmitter under modulation; SLM lasers may require modulation or high data rates (above ~2.5 Gb/s) to produce measurable linewidths.
• Safety
  • Follow laser safety classification and requirements per IEC 60825-1.

Practical applications and users

This standard is practical for:

• Test engineers and field technicians performing acceptance testing, commissioning and maintenance of fibre optic links.
• Manufacturers of optical transmitters, LEDs and laser diodes who need to certify spectral performance.
• System integrators and network operators deploying WDM systems where accurate central wavelength and spectral width affect channel spacing and crosstalk.
• Use cases include transmitter characterization, troubleshooting spectral impairments, verifying compliance with system design tolerances, and assessing SMSR for SLM sources.

Related standards

• IEC 62129 - Calibration of optical spectrum analyzers (referenced for OSA calibration)
• IEC 60825-1 - Safety of laser products (equipment classification and requirements)
• IEC 61280 series - Other parts cover complementary fibre optic subsystem test procedures

Keywords: IEC 61280-1-3:2010, central wavelength measurement, spectral width measurement, optical spectrum analyzer, fibre optic communication subsystem, RMS width, FWHM, SMSR, LED, MLM, SLM, WDM.