  The present study experimentally examines how an electron vortex beam with
orbital angular momentum (OAM) undergoes diffraction through a forked grating.
The nth-order diffracted electron vortex beam after passing through a forked
grating with a Burgers vector of 1 shows an OAM transfer of nh. Hence, the
diffraction patterns become mirror asymmetric owing to the size difference
between the electron beams. Such a forked grating, when used in combination
with a pinhole located at the diffraction plane, could act as an analyzer to
measure the OAM of input electrons.
