Optimization of a Plasmon Enhanced Field Emitter Array Using a Nano-Tip-Based Plasmonic Double-Gate Structure

Abstract

A nano-tip-based plasmonic double-gate structure (NPDS) excited by the surface plasmon polariton (SPP) resonance of the gate electrode has recently been proposed to achieve the specifications of the UV laser-induced copper cathode. The function of the NPDS is to generate a high bunch charge via nearinfrared laser-induced field emission without increasing the cathode size. In this study, we report detailed numerical studies of the proposed NPDS to elucidate the physical mechanism of SPP propagation and light-tip coupling via internal SPP resonance. The simulation results show the relationship between the internal SPP resonance and the tip-light coupling in the NPDS, and the feasibility to achieve significant field emission enhancements with the NPDS. Understanding the internal SPP field in the plasmonic double-gate structure and the light field-tip coupling process in the NPDS is of practical importance in designing field emitter devices and could become an important factor in future high-brightness free-electron laser cathodes and high-sensitivity optical biosensors. Index Terms-Surface plasmons (SPs), Nano plasmonics, Nano structure, Free-electron laser cathodeTae Young Kang is with the

Transverse structure of the wave function of field emission electron beam determined by intrinsic transverse energy

“…Such high brightness cathodes are demanded also for ultrafast electron diffraction experiments. [34][35][36] Motivated by these backgrounds, the laser-induced field emission from needleshaped etched wire field emitters [37][38][39] and the surface-plasmon-enhanced laser-induced field emission from doublegate metal nanotip array cathodes [40][41][42][43] have been intensely studied recently. Since the intrinsic transverse beam emittance is given by the cathode size and the intrinsic transverse beam spread is determined by the average transverse energy of the produced electron beam, 44 there is a renewed interest in the intrinsic transverse emittance and the transverse average energy of field emission beam in particular, for accelerator applications.…”