Page 688 - Introduction to Information Optics

12. Networking with Optics

(a)

oxc

(b)

Fig. 12.2. Optical network physical architecture, (a) Network layout, (b) Node configuration.

stimulated Brillouin scattering (SBS), and stimulated Raman scattering (SRS).
These cause optical signal distortion and/or noise, and need to be considered
in system design.
Two types of optical fibers are commonly used in optical networks. The first
is single mode fiber, which is a fiber with very small core, about 10 /im in
diameter. As the name implies, single mode fiber only supports the trans-
mission of one or two lowest-order-bound modes at the wavelength of interest.
It is used for long-distance and high-bit-rate applications. Several types of
single mode fiber are popularly used, including nondispersion-shifted fiber, also
called standard single mode fiber (SSMF), which supports wavelengths in both
the 1.3 jam region with no dispersion and in the 1.55 ^m region with chromatic
dispersion of about 17 ps/nm-km; dispersion-shifted fiber (DSF), which sup-
ports wavelengths in the 1.55 ^m region with no dispersion; and nonzero