Aperiodic lattices in a high refractive index contrast system for photonic bandgap engineering
We describe the optimal fabrication of reactively ion etched optical waveguides and photonic bandgap engineered structures in single crystal silicon-on-insulator, for use at a wavelength of around 1.54 ?m. The scattering loss in such structures is strongly dependent on the surface roughness of the waveguide. The effect of different gas mixtures on the roughness of reactively ion etched structures is investigated and an optimal etch strategy is devised for the fabrication of optically smooth sidewalls. This process is applied to the fabrication of aperiodic structures designed for multiple transmission wavelengths in the stop band. Low loss in the waveguide is demonstrated using a FabryPerot measurement technique.
photonic bandgap roughness aperiodic waveguide