We observe the propagation dynamics of surface gravity water waves, having an Airy function envelope, in both the linear and the nonlinear regimes. In the linear regime, the shape of the envelope is preserved while propagating in an 18-m water tank, despite the inherent dispersion of the wave packet. The Airy wave function can propagate at a velocity that is slower (or faster if the Airy envelope is inverted) than the group velocity. Furthermore, the introduction of the Airy wave packet as surface water waves enables the observation of its position-dependent chirp and cubic-phase offset, predicted more than 35 years ago, for the first time. When increasing the envelope of the input Airy pulse, nonlinear effects become dominant, and are manifested by the generation of water-wave solitons.
New forms of electron beams have been intensively investigated recently, including vortex beams carrying orbital angular momentum, as well as Airy beams propagating along a parabolic trajectory. Their traits may be harnessed for applications in materials science, electron microscopy, and interferometry, and so it is important to measure their properties with ease. Here, we show how one may immediately quantify these beams' parameters without need for additional fabrication or nonstandard microscopic tools. Our experimental results are backed by numerical simulations and analytic derivation.
Surface‐plasmon‐polariton waves are two‐dimensional electromagnetic surface waves that propagate at the interface between a metal and a dielectric. These waves exhibit unusual and attractive properties, such as high spatial confinement and enhancement of the optical field, and are widely used in a variety of applications, such as sensing and subwavelength optics. The ability to precisely control the spatial and spectral properties of the surface‐plasmon wave is required in order to support the growing interest in both research and applications of plasmonic waves, and to bring it to the next level. Here, we review the challenges and methods for shaping the wavefront and spectrum of plasmonic waves. In particular, we present the recent advances in plasmonic spatial and spectral shaping, which are based on the realization of plasmonic holograms for the optical nearfield.
We introduce, theoretically and experimentally, the concept of a diffraction-free "super-Airy" beam, in which the main lobe is reduced to nearly half in size with increased intensity in comparison to the main lobe of the optical Airy beam, while maintaining the same transverse acceleration. It is also observed that when the super-Airy main lobe is blocked during propagation, it recovers to the original size faster than the Airy main lobe.
Among the methods that are used in light optics for circumventing the diffraction limit are near field microscopy [3], metamaterial-based perfect lenses and super-lenses [4] and various other super resolution schemes [e.g., 5,6]. However, none of these methods have been demonstrated with matter (e.g., electron) waves. An interesting proposal for manifesting arbitrarily small spots for optical microscopy was made in 1952 by Toraldo di Francia [7]. Following earlier work in the microwave regime [8], he proposed putting a series of concentric rings near the lens pupil, thereby modulating the incoming wave so that the central focal spot could be made smaller than the Abbe-Rayleigh limit, accompanied by a peripheral ring of light. In a related development and following concepts that Magnetic Lens
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.