Bright and Ultrafast Electron Point Source Made of LaB6 Nanotip

$\text{LaB}_{6}$ has been traditionally used as a thermionic electron source for electron microscopes, but has been hardly set to practical use as cold field emitter (CFE) [1–2]. The chemical inertness, the high conductivity and the dense structure make $\text{LaB}_{6}$ a good candidate as ultrafast electron source. In the present work, we study the emission properties of LaB 6 nano-tip fabricated by focused ion beam milling, under static electric field (static emission) and under femtosecond laser illumination (ultrafast emission), using a $2.25\mu \mathrm{m}$ laser at 13 MHz.