“…The underlying accelerating effect using a single grating is inverse to the Smith-Purcell effect [2], i.e., an evanescent diffraction mode of the grating that has the same phase velocity as the passing electrons assures continuous acceleration. The inverse Smith-Purcell effect in the THz regime has been observed [3][4][5]. With recent progress in laser technology and microfabrication the realization of an optical linear accelerator is coming into reach.…”