ABSTRACT
Maximizing the capacity of the fibre as a transmitting medium is the major challenge met by network
operators. Solitonic propagation as well as wavelength division multiplexing (WDM) are among the
solutions presently proposed to increase the flow of information propagating in these networks. This
progress is made possible thanks to the development of such essential components as the erbium doped
fibre amplifier (EDFA) and frequency stabilized laser sources. However, other components to perform all
the functions (routing, filtering, dispersion compensation, etc) are not less essential. Different approaches
to design and realize the corresponding components are commonly used. The advantage of the all-fibre
approach over its competitors (micro-and integrated optics) lies undoubtedly in the fact that all-fibre
components are readily integrated to the network without significant splicing loss. In addition, their
polarization sensitivity (which would induce loss and dispersion) is intrinsicallymuch smaller than that of
their integrated optic counterparts.
