Hot Electron Generation and Manipulation on ‘structured’ Surfaces

Surface-plasmon-enhanced MeV ions from femtosecond laser irradiated, periodically modulated surfaces

“…In the PIC simulations, the effect of the SPR is manifested in terms of increase in localized electrostatic field at the grating surface. 18,19 In the present case, the grating surface absorbs 54% more laser energy compared to polished surface, which is contributed by the enhancement effect of the local electrostatic field at the grating surface. 18 The laser energy absorbed is converted to hot electrons first, as shown in Fig.…”

“…The gold coating is much thicker than the optical skin depth of laser. P-polarized, 50 fs, 800 nm, 10 Hz Ti:Sapphire laser pulses (nano-second pre-pulse contrast better than 10 À6 ) are focused by a f/4 off-axis gold coated parabolic mirror to a focal spot size of 10 lm at an incident angle of 23 , which is the phase matching angle, 17,19 for this grating to excite surface plasmon induced absorption. The polished and grating targets are mounted adjacently in a vacuum chamber (base pressure 10 À6 Torr) and are moved by a motorized precision stage to ensure a fresh target portion for each laser irradiation.…”