An optical amplifier is described that comprises at least two sections of
amplifying optical fibre and pumping means for optically pumping the
amplifying optical fibre. Optical fibre support means, for example a
channel or channels in a substrate, are also provided to hold the two or
more sections of amplifying optical fibre substantially straight during
use. The optical fibre support means also includes a means for coupling
light between the at least two sections of amplifying optical fibre. The
at least one amplifying optical fibre may comprise an Erbium doped core
to provide an erbium doped fibre amplifier (EDFA).