Superlensing effect in liquid surface waves

Abstract

We present experimental observations and numerical simulations of superlensing effect in liquid surface waves. We use rigid cylinders to create a two-dimensional periodic lattice, in which liquid surface waves propagate. Through the observation of a superlensing effect, we demonstrate the existence of negative refraction in surface waves. In addition, a complete band gap is found.

Negative Effective Gravity in Water Waves by Periodic Resonator Arrays

“…We note that the MS method includes high-order cylindrical waves [10,18] and thus can reproduce experimental results well [14,15]. In the band gap, water waves are found to be completely reflected by the structure [ Fig.…”

“…However, the effective parameters have the same positive signs as those of the background. As a result, long water waves can propagate through periodic structures [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and this is a reason why tsunamis are difficult to block by periodic structures.…”

“…Recently, the interaction of water waves and periodic structures, such as rippled bottoms and periodic vertical obstacle arrays, has attracted considerable attention [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. It is found that while the dispersions of water waves can be strongly modified by periodic structures, they remain simple in the long-wavelength range [6][7][8][9][10][11][12][13][14]. In particular, when the wavelength is longer than fourfold of the periodic length a (λ > 4a), the periodic system can be viewed as a homogeneous liquid with an effective gravitational acceleration g e and effective depth h e and thus possesses a simple dispersion…”

Ultrafast evolution of photonic eigenstates in k-space

“…This relation is usually not straightforward: owing to the imposed periodicity, bands are folded into every Brillouin zone, inducing splitting of bands and the appearance of bandgaps. As a result, exciting phenomena such as negative refraction 6,7 , autocollimation of waves 8,9 and low group velocities 10-12 arise. k-space investigations of electronic eigenstates have already yielded new insights into the behaviour of electrons at surfaces and in novel materials [13][14][15][16] .…”

Beam paths of flexural Lamb waves at high frequency in the first band within phononic crystal-based acoustic lenses

“…Analogously to heterostructures designed to achieve negative refraction of electromagnetic waves, 1,2 PCs have been conceived in order to focus acoustic waves in a frequency range where the negative refraction is possible. [3][4][5][6][7][8] It has been proved both theoretically and experimentally that such PCs can realize the subwavelength focusing or imaging. [3][4][5][6][7][8] To a certain extent, the resolution of the focusing was beyond the diffraction limit with the evanescent waves being gathered at the focusing through the bound modes.…”