Product Code: PIC2008_M804

Fabrication, Characterization and Simulation of Large-scale 3-D Photonic Crystals Using Laser-assisted Fabrication Techniques
Authors:
H. Wang, University of Nebraska - Lincoln; Lincoln NE USA
Yongfeng Lu, University of Nebraska - Lincoln; Lincoln NE USA
Presented at PICALO 2008

3-D photonic bandgap (PBG) structures were fabricated by laser-assisted fabrication techniques, including laser-assisted nanoimprinting and laser-assisted chemical vapor deposition (LCVD), based on the self-assembled silica colloidal crystals. The multilayer silica colloidal crystals self-assembled on silicon substrates were formed with isothermal heating evaporation-induced self-assembly. To infiltrate the silica colloidal crystals, the laser-assisted imprinting technique was applied using a short pulse (pulse duration 23 ns) of a KrF excimer laser. The nanosecond laser pulse instantaneously melted the silicon substrates, which infiltrated and solidified over the assembled silica particles on the substrates. By removing silica particles embedded in the silicon using hydrofluoric acid, inverse opal photonic crystals were produced. To utilize the LCVD technique, a continuous wave (CW) CO2 laser (10.6 µm wavelength) was used as the energy source. A silica-core-silicon-shell PBG structure was obtained. This technique is capable of fabricating structures with various PBGs by obtaining different silicon shell thickness with different LCVD parameters. A series of PBG structures with designed PBGs were obtained with different experimental conditions. Spectroscopic ellipsometer was used to identify specific PBGs. The plain wave expansion and transmission matrix methods were used to simulate the transmission spectra of the structures, which agreed with the experimental results.