  A proof-of-principle experiment demonstrating dielectric laser acceleration
of non-relativistic electrons in the vicinity of a fused-silica grating is
reported. The grating structure is utilized to generate an electromagnetic
surface wave that travels synchronously with and efficiently imparts momentum
on 28keV electrons. We observe a maximum acceleration gradient of 25MeV/m. We
investigate in detail the parameter dependencies and find excellent agreement
with numerical simulations. With the availability of compact and efficient
fiber laser technology, these findings may pave the way towards an all-optical
compact particle accelerator. This work also represents the demonstration of
the inverse Smith-Purcell effect in the optical regime.
