Papers by Keyword: 3D Photonic Crystals

Abstract: 3D layer-by-layer photonic crystals possess a full photonic band gap. Simulation of 3D layer-by-layer photonic crystals can optimize the parameters of the photonic crystals to get useful photonic band gap by solving Maxwell’s equations using the plane-wave-based transfer-matrix method. The relations between the parameters (rod pitch a, rod width w, rod thickness h and rod refractive index n) and the photonic band gap have been simulated. We also have fabricated a 3D layer-by-layer photonic crystal with femtosecond laser microfabrication technique through two-photon-absorption photopolymerization of resin. Its reflection spectra have been detected which agree with the simulation result.

Abstract: Two types of silver-doped glass were used for direct laser recording of 2D and 3D photonic crystals. The first contained a diffusion layer (20 microns thick) with embedded silver nanoclusters of 20-nm average radius. 2D and 3D photonic crystals of submicron lattice parameters were fabricated by nanosecond pulsed laser irradiation (l, = 355 nm) using four or five coherent intersecting beams. Under irradiation the clusters absorbing light energy are heated to high temperatures and become mobile due to the formation of liquid shells around them. Adjacent clusters move towards each other and towards the irradiated surface under local temperature gradients, form agglomerates and merge in periodically located "spots" of high light intensity in the interference field. The second type of glass, photosensitive to UV irradiation, contained in the bulk Ag+ and Ce3+ ions. Under UV irradiation excited electrons passed from Ce3+ to Ag+. The Ag atoms became neutral and under subsequent heat treatment of the glass at elevated temperatures have a tendency to form nanoclusters, thus “developing” the UV recorded patterns. Using nanosecond pulsed irradiation of 308 nm we have recorded 3D photonic crystals in the bulk of such glass.