Related papers: Watching charge separation in nanoantennas by ultr…
The ultrafast structure dynamics and surface transient electric field, which are concurrently induced by laser excited electrons of an aluminum nanofilm, have been investigated simultaneously by the same transmission electron diffraction…
An important source of innovation in nanophotonics is the idea to scale down known radio wave technologies to the optical regime. One thoroughly investigated example of this approach are metallic nanoantennas which employ plasmonic…
Ultrafast electron diffraction (UED) instruments typically operate at kHz or lower repetition rates and rely on indirect detection of electrons. However, these experiments encounter limitations because they are required to use electron…
Motivated by the need for less destructive imaging of nanostructures, we pursue point-source in-line holography (also known as point projection microscopy, or PPM) with very low energy electrons (-100 eV). This technique exploits the recent…
Solids exposed to intense electric fields release electrons through tunnelling. This fundamental quantum process lies at the heart of various applications, ranging from high brightness electron sources in DC operation to petahertz vacuum…
Evanescent light can be localized at the nanoscale by resonant absorption in a plasmonic nanoparticle or taper or by transmission through a nanohole. However, a conventional lens cannot focus free-space light beyond half of the wavelength…
Quantum emitters radiate light omni-directionally, making it hard to collect and use the generated photons. Here we propose a 3D metal-dielectric parabolic antenna surrounding an individual quantum dot as a source of collimated single…
Free electrons are essential in such diverse applications as electron microscopes, accelerators, and photo-emission spectroscopy. Often, space charge effects of many electrons are a nuisance. Confined to extremely small space-time…
The ability to manipulate optical fields and the energy flow of light is central to modern information and communication technologies, as well as quantum information processing schemes. However, as photons do not possess charge, controlling…
Controlling the wave function of free electrons is important to improve the spatial resolution of electron microscopes, the efficiency of electron interaction with sample modes of interest, and our ability to probe ultrafast materials…
The inelastic scattering of electrons is one route to study the vibrational and electronic properties of materials. Such experiments, also called electron energy-loss spectroscopy, are particularly useful for the investigation of the…
We report on spectroscopy and time-of-flight measurements using an 18 keV fast-pulsed photoelectron source of adjustable intensity, ranging from single photoelectrons per pulse to 5 photoelectrons per microsecond at pulse repetition rates…
Nanoporous metals have emerged as promising functional architectures due to their tunable optical and electronic properties, high surface areas, and versatile use in real-life applications such as sensing, catalysis, and biomedicine. While…
Plasmon excitations in metallic nanostructures can decay directly into dynamic electron-hole pairs (EHPs), exploitable for photocurrent generation. This approach has extensively been employed to develop nanoplasmonic light-sensing devices…
In the past decade, the advent of time-resolved spectroscopic tools has provided a new ground to explore fundamental interactions in solids and to disentangle degrees of freedom whose coupling leads to broad structures in the frequency…
Optical anapoles are intriguing charge-current distributions characterized by a strong suppression of electromagnetic radiation. They originate from the destructive interference of the radiation produced by electric and toroidal multipoles.…
Sub-nanometer displacement detection lays the solid foundation for critical applications in modern metrology. In-plane displacement sensing, however, is mainly dominated by the detection of differential photocurrent signals from…
Efficient coupling between light and bulk plasmons (BPs) remains a central challenge because of their inherent mode mismatch, limited penetration depth, and pronounced resonant energy mismatch between visible-range photons and BPs. In this…
Dynamics of optically-excited plasmonic nanoparticles are presently understood as a series of sequential scattering events, involving thermalization processes after pulsed optical excitation. One important step is the initiation of…
The ultrafast and ultracold electron source, based on laser cooling and trapping of an atomic gas and its subsequent near-threshold photoionization, is capable of generating electron bunches with a high transverse brightness at energies of…