Three dimensional lattices of semiconductor nanostructures were prepared using porous artificial opals as templates. Opals are natural gratings for visible light, and the template forces the semiconductor to follow the size (typically 100 nm) and symmetry (fcc) of their void-like lattice. The purpose of using this material is to match the wavelength of the emitted light from the semiconductor component with one of the lattice's own modes to enhance the luminescence efficiency. TiO2 was grown using in-cavity, multiple step synthesis by CVD. The band gap of the composite is near 3 eV. Raman scattering, absorption and photoluminescence (PL) spectra were examined for various amounts of TiO2 in opal. Transmission of the PL through the composite shows an intensity decrease at 2.15 eV which is not in the region of interband absorption of composite components. This corresponds to the structure possessing an overall refractive index between that of opal (1.45) and rutile (2.3) of 1.8.