Acoustic suppressed topological refraction in valley sonic crystals

Refraction of surface acoustic waves through 2D phononic crystals

We report on the first experimental evidence of negative refraction of surface acoustic waves, through a prism-shaped 2D phononic crystal having a solid matrix. The sample is constituted by a periodic array of air holes drilled in a Si substrate. The experiments are performed using a laser-ultrasonic technique.

Acoustic metamaterial absorbers based on multilayered sonic crystals

Recent Developments in Sonic Crystals

The properties of sonic bandgap crystals will be reviewed and recent results obtained by our group will be reported. Particularly, the homogenization method based on multiple scattering theory will be presented and applied to the case of two-dimensional (2D) structures consisting of fluid-fluid and solid-fluid composites [1, 2]. The method is general and it is employed to get the effective para...

5 Negative Refraction in Photonic Crystals

The phenomenon of negative refraction (NR) by 2D photonic crystals (PCs) is demonstrated in microwave experiments. NR by PCs is observed in 2D parallel-plate waveguide and in 3D free space measurements. Results are in excellent agreement with band structure calculation and numerical simulation. The optical properties of isotropic materials that are transparent to electromagnetic (EM) waves can ...

Negative Refraction and Imaging in Photonic Crystals

Negative refraction and left-handed electromagnetism in a photonic crystal are demonstrated in waveguide and free space experiments at microwave frequencies. Precision control to achieve tailor-made refractive indices has been achieved. The negative refraction in these photonic crystals is shown to lead to imaging by a flat lens. We have also developed a generalized theory of flat lens imaging....