Specialty Optical Fibers Handbook

proportional to A

eff

and the square of MFD, so small MFD will increase Raman

gain efficiency and lower the Raman pump power required for a desired value of

gain. The dependency of nonlinear impairments, Raman gain efficiency, and

bending-induced loss sensitivity on MFD requires finding the appropriate bal-

ance of these properties that support the performance requirements of the

intended application.

As discussed in Chapter 2, the chromatic dispersion of a silica-based fiber is a

function of the dispersion of the silica and the dispersive effects associated with

propagation within the waveguide (i.e., waveguide dispersion). In the wavelength

region where a fiber is single moded, the waveguide dispersion of the LP

01

mode

is normally negative and the