A field emitter electron gun includes at least one field emitter cathode
deposited on a substrate layer and configured to generate an electron
beam. An extraction plate having an opening therethrough is positioned
adjacent to the at least one field emitter cathode and is operated at a
voltage so as to extract the electron beam out therefrom. A meshed grid
is disposed between each of the at least one field emitter cathodes and
the extraction plate. The meshed grid is configured to operate at a
voltage so as to enhance an electric field at a surface of the at least
one field emitter cathode. The meshed grid is a one-dimensional grid
configured to focus the electron beam received from the at least one
field emitter cathode into a desired spot size.