  Metamaterials comprising assemblies of dielectric resonators have attracted
much attention due to their low intrinsic loss and isotropic optical response.
In particular, metasurfaces made from silicon dielectric resonators have shown
desirable behaviors such as efficient nonlinear optical conversion, spectral
filtering and advanced wave-front engineering. To further explore the potential
of dielectric metamaterials, we present all-dielectric metamaterials fabricated
from epitaxially grown III-V semiconductors that can exploit the high
second-order optical susceptibilities of III-V semiconductors, as well as the
ease of monolithically integrating active/gain media. Specifically, we create
GaAs nano-resonators using a selective wet oxidation process that forms a low
refractive index AlGaO (n~1.6) under layer similar to silicon dielectric
resonators formed using silicon-on-insulator wafers. We further use the same
fabrication processes to demonstrate multilayer III-V dielectric resonator
arrays that provide us with new degrees of freedom in device engineering. For
these arrays, we experimentally measure ~100% reflectivity over a broad
spectral range. We envision that all-dielectric III-V semiconductor
metamaterials will open up new avenues for passive, active and nonlinear all
dielectric metamaterials
