Simultaneous existence of photonic and phononic band gaps in nanoporous anodic aluminum oxide phoxonic crystals

We study theoretically that photonic and phononic band gaps can exist simultaneously in nanoporous anodic aluminum oxide phoxonic crystals. These two-dimensional phoxonic crystals consist of air rods on the triangular lattice infiltrated with various liquid analytes. These nanostructures have a wide range of potential applications in nanophotonics/nanophononics, lasing and sensing. It is observed that changing the material of the cylinders drilled in an aluminum oxide matrix has profound implications on the photonic and phononic band gaps of anodic alumina formed by the anodization method. Here, band structures for transverse electric and transverse magnetic polarizations of incident electromagnetic and phonon waves are considered due to the inherent optical anisotropy. The obtained results open up pathways to hypersonic modulation of light. They could lead to the design of highly efficient optomechanical devices and cavities that allow the simultaneous confinement of both photons and phonons, the significance of which is undeniable.