IEC 61280-1-3:2021

Overview

IEC 61280-1-3:2021 is part of the IEC 61280 series of fibre optic communication subsystem test procedures. This international standard defines terms and measurement procedures for central wavelength, spectral width and other spectral characteristics of optical spectra used in fibre optic communication subsystems. It covers measurements for transmitters and light sources used during system construction and maintenance, typically with the optical transmitter under modulation.

Key additions in the 2021 (3rd) edition include:

• Measurement of signal-to-source spontaneous emission ratio (SSER)
• Updated title reflecting the additional measurement
• Guidance on resolution bandwidth (RBW) for side-mode suppression ratio (SMSR) measurements
• Use of a calibrated optical wavelength meter (OWM) for accurate single-longitudinal-mode (SLM) laser wavelength measurements

Key topics and technical requirements

• Definitions: centre wavelength, peak wavelength, centroidal wavelength, half-power wavelength, and related spectral terms.
• Spectral width metrics: RMS spectral width, n-dB-down spectral width, full-width at half-maximum (FWHM) and other standardized ways to quantify spectral width.
• Additional spectral characteristics: Side-Mode Suppression Ratio (SMSR) and Signal-to-Source Spontaneous Emission Ratio (SSER).
• Measurement apparatus: calibrated Optical Spectrum Analyzer (OSA), calibrated Optical Wavelength Meter (OWM), power supplies, modulators/input signal sources, and test cords.
• Procedures: two main measurement procedures (Method A and Method B) with guidance on setup, spectrum analyzer control settings, and wavelength meter settings.
• Spectral types addressed: continuous spectra (e.g., LEDs), multilongitudinal-mode (MLM), multitransverse-mode (MTM) and single-longitudinal-mode (SLM) laser spectra.
• Normative references: safety and calibration standards such as IEC 60825-1, IEC 62129-1 and IEC 62129-2.

Practical applications and users

IEC 61280-1-3:2021 is applicable for:

• Fibre optic system engineers and designers performing transmitter characterization
• Test laboratories and quality assurance teams verifying central wavelength and spectral width for compliance
• Manufacturers of LEDs and laser diodes (LDs) preparing product datasheets and acceptance tests
• Field technicians and maintenance teams conducting system construction, installation verification and troubleshooting
• Calibration facilities using calibrated OSA/OWM for precision wavelength and spectral measurements

Practical outcomes include reliable specification of central wavelength and spectral width for link design, verification of transmitter behavior under modulation, and standardized reporting of SMSR and SSER for laser sources.

Related standards

• IEC 60825-1 - Safety of laser products
• IEC 62129-1 - Calibration of optical spectrum analyzers
• IEC 62129-2 - Calibration of Michelson interferometer wavelength meters

Keywords: IEC 61280-1-3, central wavelength, spectral width, SMSR, SSER, optical spectrum analyzer, optical wavelength meter, LED spectrum, SLM, MLM, fibre optic test procedures.