We report the optimal focusing of acoustic vortex beams by using flat lenses based on a Fresnel- spiral diffraction grating. The flat lenses are designed by spiral-shaped Fresnel zone plates composed of one or several arms. The constructive and destructive interferences of the diffracted waves by the spiral grating result in sharp acoustic vortex beams, following the focal laws obtained in analogy with the Fresnel zone plate lenses. In addition, we show that the number of arms determines the topologi- cal charge of the vortex, allowing the precise manipulation of the acoustic wave field by flat lenses. The experimental results in the ultrasonic regime show excellent agreement with the theory and full-wave numerical simulations. A comparison...
Modeling and experimental results of an ultrasonic aperiodic flat lens for use in air are presented....
Vortex lenses produce special wavefronts with zero-axial intensity, and helical phase structure. The...
Acoustic flat lensing is achieved here by tuning a phononic array to have indefinite medium behavior...
We report the optimal focusing of acoustic vortex beams by using flat lenses based on a Fresnel- spi...
[EN] Acoustic vortices with subwavelength dimensions and tunable topological charge are theoreticall...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
We investigate numerically and experimentally highly efficient acoustic lenses based on the principl...
We investigate numerically and experimentally highly efficient acoustic lenses based on the principl...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
[EN] The focusing properties of Fresnel Zone Plates (FZPs) against frequency are analyzed in this wo...
[EN] Vortex beams, characterized by a collimated wavefront with a phase dislocation at their princip...
AbstractWe report first-order Bessel beam formation by means of a novel passive acoustic device. The...
Modeling and experimental results of an ultrasonic aperiodic flat lens for use in air are presented....
Vortex lenses produce special wavefronts with zero-axial intensity, and helical phase structure. The...
Acoustic flat lensing is achieved here by tuning a phononic array to have indefinite medium behavior...
We report the optimal focusing of acoustic vortex beams by using flat lenses based on a Fresnel- spi...
[EN] Acoustic vortices with subwavelength dimensions and tunable topological charge are theoreticall...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
We investigate numerically and experimentally highly efficient acoustic lenses based on the principl...
We investigate numerically and experimentally highly efficient acoustic lenses based on the principl...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
The formation of high-order Bessel beams by a passive acoustic device consisting of an Archimedes' s...
[EN] The focusing properties of Fresnel Zone Plates (FZPs) against frequency are analyzed in this wo...
[EN] Vortex beams, characterized by a collimated wavefront with a phase dislocation at their princip...
AbstractWe report first-order Bessel beam formation by means of a novel passive acoustic device. The...
Modeling and experimental results of an ultrasonic aperiodic flat lens for use in air are presented....
Vortex lenses produce special wavefronts with zero-axial intensity, and helical phase structure. The...
Acoustic flat lensing is achieved here by tuning a phononic array to have indefinite medium behavior...