Extreme ultraviolet (EUV) light sources have matured, both in brightness, as well as in producing ever shorter attosecond light pulses.
Contrary, transmissive EUV optics remain sparse due to material absorption. Thus, EUV microscopy today focuses mainly on lensless techniques or secondary observables such as photoelectrons. EUVORAM (Extreme-Ultraviolet Meta-Optics for Attosecond Microscopy) will experimentally demonstrate that meta-optical devices are realizable in the EUV using a novel design approach and that they can solve the current lack of transmissive EUV optics. By emulating the spatial phase profiles of aspheric lenses, we will fabricate focusing metaoptics
yielding near-diffraction limited microfoci in the EUV. In combination with contemporary attosecond pulse sources based on laserdriven high-harmonic generation, these meta-lenses will enable high-numerical-aperture EUV focusing that maintains attosecond pulse durations. EUVORAM will exploit this capacity to build a light microscope that unifies attosecond time and nanometer spatial resolution.
After its demonstration, we will apply this microscope to isolate the ultrafast hot electron dynamics and sub-nanometer charge transfers in individual plasmonic core@shell nanoparticles using spatially resolved attosecond transient absorption spectroscopy. EUVORAM will be one of the first projects connecting attosecond science and dielectric meta-surfaces. The planned EUV meta-optics and their novel design will undercut the current short-wavelength limit of meta-surface optics by a factor of four and thus directly redefine the
state-of-the-art. The project will push lens-based microscopy to unprecedented time resolutions and at the same time allow hyperspectral attosecond imaging. The latter will free attosecond experiments from observing ensemble averages and provide spatially resolved insight in the light-matter-interaction of photonic nanodevices.