Proposed square spiral microfabrication architecture for large three-dimensional photonic band gap crystals

We present a blueprint for a three-dimensional photonic band gap (PBC) mate rial that is amenable to Large-scale microfabrication on the optical scale using glancing angle deposition methods. The proposed chiral crystal consis ts of square spiral posts on a tetragonal Lattice. In the case of silicon p osts in air (direct structure), the full PBC can be as Large as 15% of the gap center frequency, whereas for air posts in a silicon background (invert ed structure) the maximum PEG is 24% of the center frequency. This PBC occu rs between the fourth and fifth bands of the photon dispersion relation and is very robust to variations (disorder) in the geometrical parameters df t he crystal.