  Using a time-resolved optically-pumped scanning optical microscopy technique
we demonstrate the laser-driven excitation and propagation of spin waves in a
20-nm film of a ferromagnetic metallic alloy Galfenol epitaxially grown on a
GaAs substrate. In contrast to previous all-optical studies of spin waves we
employ laser-induced thermal changes of magnetocrystalline anisotropy as an
excitation mechanism. A tightly focused 70-fs laser pulse excites packets of
magnetostatic surface waves with a $e^{-1}$ propagation length of 3.4 $\mu$m,
which is comparable with that of permalloy. As a result, laser-driven
magnetostatic spin waves are clearly detectable at distances up to 10 $\mu$m,
which promotes epitaxial Galfenol films to the limited family of materials
suitable for magnonic devices. A pronounced in-plane magnetocrystalline
anisotropy of the Galfenol film offers an additional degree of freedom for
manipulating the spin waves' parameters. Reorientation of an in-plane external
magnetic field relative to the crystallographic axes of the sample tunes the
frequency, amplitude and propagation length of the excited waves.
