International Telecommunication Union/ITU Telcommunication Sector

Characteristics of a cut-off shifted single-mode optical fibre and cable - Study Group 15
 N G.654

Annotation

This Recommendation describes a single-mode optical fibre and cable which has the zero-dispersion wavelength around 1300 nm wavelength, which is loss-minimized and cut-off shifted at a wavelength around 1550 nm, and which is optimized for use in the 1530-1625 nm region.

This very low loss cut-off shifted fibre (CSF) can be used for long-distance digital transmission applications such as long-haul terrestrial line systems and submarine cable systems using optical amplifiers. The geometrical, optical (attenuation, cut-off wavelength, chromatic dispersion and polarization mode dispersion, etc.), transmission and mechanical characteristics of this CSF are described below.

Some provisions are made to support transmission at higher wavelengths up to 1625 nm. The geometrical, optical, transmission and mechanical parameters are described below in three categories of attributes:

• fibre attributes are those attributes that are retained throughout cabling and installation;

• cable attributes that are recommended for cables as they are delivered;

• link attributes that are characteristics of concatenated cables, describing estimation methods of system interface parameters based on measurements, modelling, or other considerations. Information for link attributes and system design are given in Appendix I.

This Recommendation, and the different performance categories found in the tables of clause 7, are intended to support the following related-system Recommendations:

• [b-ITU-T G.957];