Focusing surface waves using an axicon

Focusing guided waves using surface bonded elastic metamaterials

Focusing surface waves with an inhomogeneous metamaterial lens.

We propose a new type of surface wave lens that is made of a circular in-plane inhomogeneous metamaterial slab and numerically demonstrate its capability to focus surface waves at optical frequencies. This approach can achieve a smaller focal spot size than the previously demonstrated Ag plasmonic lens. The use of inhomogeneous metamaterials is to decrease the high losses that are usually assoc...

Axicon lens for coherent matter waves.

We have realized a conical matter wave lens. The repulsive potential of a focused laser beam was used to launch a Bose-Einstein condensate into a radially expanding wavepacket whose perfect ring shape was ensured by energy conservation. In spite of significant interactions between atoms, the spatial and velocity widths of the ring along its radial dimension remained extremely narrow, as also co...

Focusing and Extraction of Light mediated by Bloch Surface Waves

The control of emission from localized light sources is an objective of outstanding relevance in nanophotonics. In a recent past, a large number of metallic nanostructures has been proposed to this end, wherein plasmonic modes are exploited as energy carriers on a subwavelength scale. As an interesting alternative, we present here the use of surface modes on patterned dielectric multilayers to ...

Phase changes of ultrasonic surface and bulk waves through focusing measured using non-contact ultrasonic methods

Focusing an ultrasonic surface or bulk wave to a point can maximise the amount of ultrasonic energy at a point and increase the sensitivity of a measurement. Using noncontact ultrasonic methods we focus an ultrasonic wave pulse on or in a sample. Focusing can be achieved by using a shaped source or by the surface profile of the sample itself. Experiments and modelling confirm the known result t...