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. 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.