Mechanism of Laser-induced Field Emission

TL;DR

This study investigates the mechanism of laser-induced field emission from tungsten tips by measuring electron energy distributions, confirming the role of electron dynamics and providing insights for optimizing pulsed electron sources.

Contribution

The paper provides experimental confirmation of the emission mechanism and highlights the importance of electron dynamics in laser-induced field emission.

Findings

Field emission from photo-excited nonequilibrium electrons observed

No enhancement of emission due to optical electric fields up to 1.3 V/nm

Simulations show electron dynamics significantly influence emission

Abstract

We have measured electron energy distribution curves (EDCs) of the laser-induced field emission from a tungsten tip. Field emission from photo-excited nonequilibrium electron distributions were clearly observed, while no enhanced field emission due to optical electric fields appeared up to values of 1.3 V/nm. Thus, we experimentally confirm the emission mechanism. Simulated transient EDCs show that electron dynamics plays a significant role in the laser-induced field emission. The results should be useful to find optimal parameters for defining the temporal and spectral characteristics of electron pulses for many applications based on pulsed field emission.