Patent ID: 7405866

Claim:
An apparatus for controlling propagation of incident electromagnetic radiation, comprising a composite material having electromagnetically reactive cells of small dimension relative to a wavelength of the incident electromagnetic radiation, wherein at least one of a capacitive and inductive property of at least one of said electromagnetically reactive cells is temporally controllable to allow temporal control of an associated effective refractive index encountered by the incident electromagnetic radiation while propagating through said composite material, each of said electromagnetically reactive cells comprising at least one electrical conductor and a substrate, said temporal control comprising controlling a carrier population within said substrate, said substrate comprising a semiconductor material having a bandgap energy, said wavelength of said incident electromagnetic radiation corresponding to a first frequency below a bandgap radiation frequency corresponding to said bandgap energy, said carrier population being controlled by introducing control radiation into said electromagnetically reactive cells at a second frequency at or above said bandgap radiation frequency, said electromagnetically reactive cells forming a surface receiving the incident electromagnetic radiation, further comprising a modulation input device transferring said control radiation onto said surface according to a modulation intensity pattern, said apparatus spatially modulating phase information in said incident electromagnetic radiation according to said modulation intensity pattern.