scope:

This Recommendation describes a single-mode fibre with chromatic dispersion that is greater than some non-zero value throughout the wavelength range of 1460-1625 nm. This dispersion reduces the growth of non-linear effects that can be particularly deleterious in Dense Wavelength Division Multiplexing (DWDM) systems. This fibre uses non-zero dispersion to reduce four-wave mixing and cross-phase modulation over a wider wavelength range than the fibre described in [b-ITU-T G.655]. Extensions are possible, in the future, to wavelengths beyond the 1460-1625 nm region (to be determined). 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 fibre can be utilized for CWDM and DWDM systems throughout the extended wavelength transmission region between 1460 and 1625 nm.

This Recommendation, and the category found in the table of clause 7, is intended to support the following related system Recommendations:

• [b-ITU-T G.691];

• [b-ITU-T G.692];

• [b-ITU-T G.693];

• [b-ITU-T G.695];

• [b-ITU-T G.959.1];

• [b-ITU-T G.698.1];

• [b-ITU-T G.696.1].

The meaning of the terms used in this Recommendation and the guidelines to be followed in the measurement to verify the various characteristics are given in [ITU-T G.650.1] and [ITU-T G.650.2]. The characteristics of this fibre, including the definitions of the relevant parameters, their test methods and relevant values, will be refined as studies and experience progress.