Efficient light coupling for optically excited high-density metallic nanotip arrays

Abstract

Ultrafast electron pulses can be produced from sharp metallic tips illuminated by femtosecond near infrared laser pulses. Use of an array of metallic nanotips for high charge bunch generation and accelerator applications is also feasible but the small fraction of the emitter tip area limits the quantum efficiency. We therefore propose a submicron-pitch, high-density nanotip array device with a gate electrode, that can support surface-plasmon polaritons. From a theoretical analysis for a device with an asymmetric emitter position, a factor ~30 increased array quantum efficiency is demonstrated.

The laser assisted field electron emission from carbon nanostructure

“…(5,6) shows (see Fig. 5) that the electron temperature increases up to 5500 K under irradiation of NCF with 0.75 mJ pulse.…”

“…The laser assisted electron emission has opened a way towards the time resolved electron microscopy [4,5] because electrical gating and source control enable time resolution down to picoseconds, while using optical control enables creation of electron pulses with duration down to tens of femtoseconds [6]. Such dense and short electron bunches can resolve important problems in electron microscopy, X-ray microscopy, and time-resolved electron diffraction, which is of special interest for industry and science.…”

Numerical study of the laser-tip coupling in surface plasmon assisted stacked-double-gate field emitter arrays

“…1, consists of sub-micron-pitch molybdenum nanotips with the copper double-gate electrodes. The double-gate electrode layers on top of the nanotips for the electron extraction and the beam collimation, 18 act also to enhance the coupling of the laser pulses to the nanotip apexes 3,4 at the same time. The optical field enhancement at the tip apexes is a result of the geometrical field enhancement 17 and the near field coupling of the nanotip with the electric field of the resonantly excited SPP near the gate edge at the optical frequency determined by the dispersion of the surface-plasmon 19,20 of the material and the period of the apertures.…”

Bulk Molybdenum Spindt Field Emission Arrays

“…Samples were irradiated with a white light source with an inclusive wavelength of 300-700 nm 13 . Figure 4b shows the two tungsten probes utilized as the anode and ground probes, respectively.…”