A multiple electron beam source comprises a photon source to generate a photon beam, a lens to focus the photon beam, a photocathode having a photon receiving surface and an electron emitting surface, and an array of electron transmission gates spaced apart from the electron emitting surface of the photocathode by a distance dg. Each electron transmission gate comprises a membrane; an anode on a first surface of the membrane; an insulator on a second surface of the membrane; an aperture through the anode, insulator and membrane; and a gate electrode on the insulator. The gate electrode is positioned about the aperture and capable of receiving a gate control voltage that controls the transmission of electrons through that electron transmission gate. In one version, the multiple electron beam source comprises a photocathode stage assembly to move the photocathode relative to the array of electron transmission gates. In one version, the multiple electron beam source also comprises a plasmon-generating photon transmission plate comprising an array of photon transmission apertures and exterior surfaces capable of supporting plasmons.