Topological optical and phononic interface mode by simultaneous band inversion

Band inversion in one-dimensional superlattices is a strategy to generate topological interface modes electronics, optics, acoustics, and nanophononics. Despite their potential for the control of topologically robust interactions, most realizations these states have so far explored only single kind excitation. In this work, we design fabricate GaAs/AlAs devices with simultaneously inverted band structures light phonons. We experimentally observe colocalized 1.34 eV photons by optical reflectivity 18 GHz phonons coherent phonon generation detection. Through numerical simulations, demonstrate ensuing robustness Brillouin interaction between them respect specific type disorder. Furthermore, theoretically analyze efficiency time-domain scattering different designs presenting deduce set engineering rules. Potential future applications include optomechanical resonators material system compatible active media such as quantum wells dots.