  Efficient manipulation of light with sound in subwavelength-sized volumes is
important for applications in photonics, phononics and biophysics, but remains
elusive. We theoretically demonstrate the control of light with MHz-range
ultrasound in a subwavelength, 300 nm wide water-filled hole with a 100 nm
radius air bubble. Ultrasound-driven pulsations of the bubble modulate the
effective refractive index of the hole aperture, which gives rise to spectral
tuning of light transmission through the hole. This control mechanism opens up
novel opportunities for tuneable acousto-optic and optomechanical
metamaterials, and all-optical ultrasound transduction.
