Elastic Wave — 2D Phononic Crystal Band Gap

Bragg scattering gaps: periodic inclusions block elastic wave propagation

Crystal Parameters

Bragg condition: 2d·sinθ = nλ
First gap: ω ≈ πc/a
Filling fraction: f = π(r/a)²
Gap width ∝ contrast·f
Evanescent waves in gap
Mie resonance gaps also possible
In bandgap:
λ/a ratio:
Gap center:
Transmission: