Steering sound with light

Phononic circuits have been emerging as a growing field of research for applications in optical signal processing, sensing and emerging quantum technologies. We describe the design of a micron-scale on-chip patterned silicon device supporting i) helical transport of phonons along the interface of two topologically distinct domains, ii) photonic crystal optical cavities as a means of excitation and read-out of these mechanical vibrations via optomechanical parametric coupling. Our unique design can be characterized as a multi-scale optomechanical crystal, and we will describe possibilities to test its operation in experimental devices.