Nanooptics and electrons: From strong-field physics at needle tips to dielectric laser acceleration

We will report on control of electrons near nanoscale structures. In the first part of the talk, we will present results on strong-field physics in the near-field of a nanometer sharp needle tip. In particular, we will focus on field enhancement measurements with the laser-emitted electrons, and simulations thereof. In the second part we will show that charged particles can be efficiently and continuously accelerated with the optical carrier field of laser pulses provided that dielectric structures are employed to shape the phase front of the laser pulse. We show an experimental demonstration of dielectric laser acceleration of non-relativistic 30-keV electrons with a peak acceleration gradient of 25MeV/m, already on par with nowadays RF accelerators. With relativistic electrons, the acceleration gradient should exceed 1 GeV/m.