Electron emission by long and short wavelength lasers: essentials for the design of plasmonic photocathodes

Theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Energy of photons in long wavelength lasers is less than the work function of the photocathode material, and can only emit electrons via tunneling through the potential barrier. The optical resonance effect (e.g. plasmonic resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design optical resonant surfaces (e.g. metasurfaces) for electron emission applications.