  Nonlinear acoustic interactions in liquids are effectively stronger than
nonlinear optical interactions in solids. Thus, harnessing these interactions
will offer new possibilities in the design of ultra-compact nonlinear photonic
devices. We theoretically demonstrate a hybrid, liquid-state and nanoplasmonic,
source of optical frequency combs compatible with fibre-optic technology. This
source relies on a nanoantenna to harness the strength of nonlinear acoustic
effects and synthesise optical spectra from ultrasound.
