Using full opto-acoustic numerical simulations, we demonstrate enhancement
and suppression of the SBS gain in a metamaterial comprising a subwavelength
cubic array of dielectric spheres suspended in a dielectric background
material. We develop a general theoretical framework and present several
numerical examples using technologically important materials. For As2S3
spheres in silicon, we achieve a gain enhancement of more than an order of
magnitude compared to pure silicon, and for GaAs spheres in silicon, full
suppression is obtained. The gain for As2S3 glass can also be strongly
suppressed by embedding silica spheres. The constituent terms of the gain
coefficient are shown to depend in a complex way on the filling fraction. We
find that electrostriction is the dominant effect behind the control of SBS in
bulk media.Comment: 5 pages, 5 figure