This part of IEC 62129 is applicable to instruments measuring the vacuum wavelength or
optical frequency emitted from sources that are typical for the fibre-optic communications
industry. These sources include Distributed Feedback (DFB) laser diodes, External Cavity
lasers and single longitudinal mode fibre-type sources. It is assumed that the optical radiation
will be coupled to the wavelength meter by a single-mode optical fibre. The standard describes
the calibration of wavelength meters to be performed by calibration laboratories or by
wavelength meter manufacturers. This standard is part of the IEC 62129 series on the
calibration of wavelength/optical frequency measurement instruments. Refer to IEC 62129 for
the calibration of optical spectrum analyzers.