  Soliton fusion is a fascinating and delicate phenomenon that manifests itself
in optical fibers in case of interaction between co-propagating solitons with
small temporal and wavelengths separation. We show that the mechanism of
acceleration of trailing soliton by dispersive waves radiated from the
preceding one provides necessary conditions for soliton fusion at the advanced
stage of supercontinuum generation in photonic crystal fibers. As a result of
fusion large intensity robust light structures arise and propagate over
significant distances. In presence of small random noise the delicate condition
for the effective fusion between solitons can easily be broken, making the
fusion induced giant waves a rare statistical event. Thus oblong-shaped giant
accelerated waves become excellent candidates for optical rogue waves.
