Simultaneous localization of photons and phonons in two-dimensional periodic structures

We demonstrate theoretically the simultaneous localization of photons and phonons in the same spatial region by introducing lattice defects in a periodic array of dielectric/elastic material that exhibits gaps for both electromagnetic and elastic waves. Transverse electromagnetic waves, pure shear elastic waves, and mixed shear and dilatation elastic waves were simultaneously localized. The coexistent localization of light and sound can have a strong influence on photon-phonon interactions (i.e., optical cooling) and the possibility of dual acoustic-optical devices that can integrate the management of sound, heat, and light.