In this work, acoustic phase-reconstruction is studied and experimentally demonstrated in a
triangular lattice two-dimensional phononic crystal (PnC) composed of steel rods in air.
Owning to the fact that two bands of this triangular lattice PnC touch at the K/K′ point and
thus give rise to a conical Dirac cone, acoustic waves transmitting through this PnC can
exhibit a pseudo-diffusion transportation feature, producing a reconstructed planar
wavefront in the far field away from the interface of the PnC. Such phase reconstruction …