The stimulated emission from an organic dye adsorbed within the void network of a NP 1D (photonic crystals) PC, was studied. The nanoparticle one-dimensional photonic crystals (NP 1DPCs) were assembled by polyelectrolyte-assisted layer-by-layer deposition with subsequent calcination of the films to remove the polymer components. Each layer was prepared by spin-coating a block-copolymer-templated titania- or silica-based sol solution followed by a calcination step. To maximize the photonic-crystal effect, PCs consisting of eleven bilayers, compared to the four-bilayer NP 1D PCs, were fabricated with good structural and optical quality over 2 cm ×2 cm areas. The effective refractive index of the SiO2 and TiO2 layers and the TiO2 layers was determined by spectroscopic ellipsometry to be 1.21 and 1.80 at 598 nm. A central feature of the 1D PC employed in this proof-of-concept study is the nanoparticle-generated porosity, which enables the uptake of a high loading of R6G dye.