Top-illuminated structures for dielectric laser acceleration published in Optics Express
In dielectric laser acceleration, nanostructures etched into silicon are used to convert free-space ultrashort laser pulses to accelerate particles. This current approach, namely, illuminating the structure with a laser directed nearly horizontally to the substrate, is experimentally challenging and, as it turns out, not quite necessary for most experiments and practical applications. In this work we experimentally demonstrate and numerically verify the efficacy of top-illuminated structures, and measure a maximum acceleration gradient of 49.2 ± 3.1 MeV/m. We discuss how, in practice, this approach proves superior to the current standard in the field, and expect it to become the definitive choice for nanophotonic particle laser acceleration. The paper is published open-access in Optics Express.