Abstract: The present invention relates to photonic band gap (PBG) materials and more specifically, it describes a new type of photonic crystal structure which exhibits a large and complete three-dimensional PBG. This PBG is highly robust to the effects of disorder. The photonic crystal has a tetragonal or hexagonal lattice symmetry and is comprised of a lattice of polygonal spiral posts of a high refractive Index material in a low index background. The corresponding inverse structure comprises a lattice of low refractive index posts in a high refractive index background also has a very large PBG. These new photonic crystals exhibit very large (up to 23.6% when made of silicon and nearly 29% when made of germanium) complete 3D photonic band gaps. The posts exhibit a spiral profile and all the spiral posts wind in phase with each other. The identity of the winding phase from one post to the next makes the present invention amenable to micro-fabrcation using the Glancing Angle Deposition (GLAD).

Abstract: The present invention relates to photonic band gap (PBG) materials and more specifically, it describes a new type of photonic crystal structure which exhibits a large and complete three-dimensional PBG. This PBG is highly robust to the effects of disorder. The photonic crystal has a tetragonal or hexagonal lattice symmetry and is comprised of a lattice of polygonal spiral posts of a high refractive index material in a low index background, The corresponding inverse structure comprises a lattice of low refractive index posts in a high refractive index background also has a very large PBG. These new photonic crystals exhibit very large (up to 23.6% when made of silicon and nearly 29% when made of germanium) complete 3D photonic band gaps. The posts exhibit a spiral profile and all the spiral posts wind in phase with each other. The identity of the winding phase from one post to the next makes the present invention amenable to micro-fabrication using the Glancing Angle Deposition (GLAD).