Simultaneous beam guides of electromagnetic and acoustic waves in defect-free phoxonic crystals using self-collimation effect

Abstract

We report the coexistence of photonic and phononic beam guides in defect-free phoxonic crystals that simultaneously allow a virtually diffractionless propagation for electromagnetic (EM) and acoustic waves. Functionality is achieved via self-collimation effects by intentionally creating simultaneous flat equal-frequency contours of EM waves for both polarizations and acoustic waves. Phoxonic self-collimation in a passband shows considerable advantages over the defect-based phoxonic bandgap effect in achieving phoxonic beam guides. The results thus provide a potential platform to achieve various acoustic-optic devices and highly controllable photon-phonon interactions by simultaneously manipulating the photonic and phononic dispersion.