Related papers: Selective mode conversion and rainbow trapping via…
Defects play a crucial role in the physical properties of crystals, whether for classical or quantum systems. For example, in photonic/phononic crystals, defects can serve as precise guidance and localization of classical electromagnetic or…
We demonstrate that a rainbow-based metasurface, created by a graded array of resonant rods attached to an elastic beam, operates as a mechanical delay-line by slowing down surface elastic waves to take advantage of wave interaction with…
The trapping of ultracold atoms using two-colour evanescent light waves formed by propagating modes of suspended optical rib waveguides is modelled in different configurations. Reducing the anisotropy of the two-colour evanescent optical…
We theoretically and numerically analyze a five-layer "trapped rainbow" waveguide made of a passive negative refractive index (NRI) core layer and gain strips in the cladding. Analytic transfer-matrix calculations and full-wave time-domain…
We demonstrate, both experimentally and numerically, the mechanical rainbow trapping effect and the mechanical Bloch oscillations for torsional waves propagating in chirped mechanical beams. After extensive simulations, three…
The phenomenon of trapping broad spectrum of light is known as `rainbow trapping' and achieved using all-dielectric, hybrid metallo-dielectric or all-metallic configurations. In the latter cases, unavoidable ohmic losses result in…
Understanding how evanescent modes mediate energy transfer in tapered elastic waveguides is of paramount interest, as it unlocks new strategies for wave control and manipulation. Evanescent modes play a crucial role in energy localization…
In this work, tunable acoustic energy concentrations are realized based on pseudo-spin locking waveguides and topological rainbow trappings. Firstly, a tunable pseudo-spin locking is proposed, and the broad acoustic energy transport and…
We experimentally achieve selective wave filtering and polarization control in a three-dimensional elastic frame embedding local resonators. By connecting multi-resonating elements to a frame structure, a complete low-frequency,…
In this study, we investigate the phenomenon of mode conversion in elastic bulk waves using coupled hexapole resonances. A metamaterial slab is proposed enabling the complete conversion between longitudinal and transverse modes. Each unit…
Robustly manipulating waves on subwavelength scales can be achieved by, firstly, designing a structure with a subwavelength band gap and, secondly, introducing a defect so that eigenfrequencies fall within the band gap. Such frequencies are…
An analytical method for the visualization and prediction of trapped-mode resonances based on the dimensions of a dispersive microwave network is described. The method as explained is intuitive, easy to implement, and has proven itself to…
We study the cooperative optical coupling between regularly spaced atoms in a one-dimensional waveguide using decompositions to subradiant and superradiant collective excitation eigenmodes, direct numerical solutions, and analytical…
Since the dawn of modern optics and electromagnetics, optical prism is one of the most fascinating optical elements for refracting light. Exploiting its frequency dispersive behaviour, a prism is able to refract different frequencies in…
In this manuscript, the temporal rainbow effect for surface acoustic waves (SAW) is illustrated through a temporal analog of space metagradings. We show that a time-modulated array of mechanical resonators induces a wavenumber-preserving…
We report the observation of almost perfect light tunneling inhibition at the edge and inside laser-written waveguide arrays due to band collapse. When the refractive index of the guiding channels is harmonically modulated along the…
Optical resonators enable the generation, manipulation, and storage of electromagnetic waves. They are widely used in technology and fundamental research, in telecommunications, lasers and nonlinear optics, ultra-sensitive measurements in…
Recently we have suggested that two-dimensional broadband transformation optics devices based on metamaterial designs may be built using tapered waveguides. Here we review application of this principle to broadband electromagnetic cloaking,…
Exitation of atomic levels due to interaction with electromagnetic waves has been the subject of numerous works, both experimental and theoretical. This topic became of interest in accelerator physics in relation to high efficiency charge…
We study specific features of resonant mode conversion in nonlinear waveguides stimulated by the bi-harmonic longitudinal modulation of its parameters, which includes changes of the waveguide depth as well as its bending (in the…