Fabrication, characterization and simulation of noval 3-D photonic bandgap structures using laser chemical vapor deposition

Three-dimensional (3-D) photonic bandgap (PBG) structures were fabricated by laser chemical vapor deposition (LCVD) of silicon among self-assembled silica particles on silicon substrates. The multilayer self-assembly of colloidal silica particles were formed on silicon substrates using isothermal heating evaporation approach. A Nd:YAG laser (1064 nm wavelength) was used as the energy source for LCVD processing. A silica-silicon shell PBG structure was obtained. By removing silica particles embedded in the silicon using hydrofluoric acid, another air-silicon shell PBG was produced. This technique is capable of fabricating the complete PBG, which is predicted by theoretical calculations with the plan-wave method. This might enable us to engineer the position of PBG by flexibly varying the silica particle size. Ellipsometry was used to identify specific bandgaps at various crystal directions for both structures. The transmission matrix method is used to simulate the transmission spectra of the structures, which agree with the experimental results.