3.3 Design and Characteristics of SMFs
131
Fig. 3.17 Typical mode-field diameter variations with wavelength for 1300 nm-optimized,
dispersion-shifted, and dispersion-flattened single-mode fibers
equipment racks. Furthermore, as Sect. 3.5 describes, the development of bendinsensitive fibers allows much tighter coiling of these fibers in optoelectronic packages. In addition, use of these bend-insensitive fibers in jumper cables between
equipment modules greatly reduces bending loss effects when they are installed in
highly confined equipment racks.
3.4 ITU-T Standards for Fibers
The ITU-T is a leading organization that develops and publishes a wide range of
internationally recognized recommendations and standards. The organization has
created a series of recommendations for manufacturing and testing various classes
of multimode and single-mode optical fibers used in telecommunications. These
documents give guidelines for bounds on fiber parameters, such as core and cladding
sizes and circularity, attenuation, cutoff wavelength, and chromatic dispersion. The
recommendations allow a reasonable degree of design flexibility, so that fiber manufacturers can improve products and develop new ones within the guidelines given in
the performance specifications.
Table 3.2 summarizes the ITU-T recommendations for multimode and singlemode optical fibers used in long-distance, access, and enterprise networks. The
following subsections describe the basic characteristics of these fibers. The recommendations are available for downloading at www.itu.int.
131
Fig. 3.17 Typical mode-field diameter variations with wavelength for 1300 nm-optimized,
dispersion-shifted, and dispersion-flattened single-mode fibers
equipment racks. Furthermore, as Sect. 3.5 describes, the development of bendinsensitive fibers allows much tighter coiling of these fibers in optoelectronic packages. In addition, use of these bend-insensitive fibers in jumper cables between
equipment modules greatly reduces bending loss effects when they are installed in
highly confined equipment racks.
3.4 ITU-T Standards for Fibers
The ITU-T is a leading organization that develops and publishes a wide range of
internationally recognized recommendations and standards. The organization has
created a series of recommendations for manufacturing and testing various classes
of multimode and single-mode optical fibers used in telecommunications. These
documents give guidelines for bounds on fiber parameters, such as core and cladding
sizes and circularity, attenuation, cutoff wavelength, and chromatic dispersion. The
recommendations allow a reasonable degree of design flexibility, so that fiber manufacturers can improve products and develop new ones within the guidelines given in
the performance specifications.
Table 3.2 summarizes the ITU-T recommendations for multimode and singlemode optical fibers used in long-distance, access, and enterprise networks. The
following subsections describe the basic characteristics of these fibers. The recommendations are available for downloading at www.itu.int.