Tailoring of the unit cell structure of autocloned photonic crystals

This paper discusses how to enhance the ability to tailor material structures within a unit cell of photonic crystals fabricated by the autocloning method which is based on stacking corrugated multilayers of constant thickness by a bias-sputtering process. We developed a new process by introducing reactive ion etching into autocloning, and thus created a novel structure having multilayers whose thicknesses are modulated, and the new structure has bandgaps in the directions parallel to the substrate. The new process allows photonic bands of autocloned photonic crystals to be designed with greater controlability, which should facilitate the application of autocloning, such as for in-plane optical circuits.