Three-dimensional square spiral photonic crystal nanostructures by glancing angle deposition

We demonstrate the fabrication of a three-dimensional photonic band gap nanostructure using the unique Glancing Angle Deposition (GLAD) thin film technique. This innovative photonic structure is based on a tetragonal, square spiral symmetry found in FCC and diamond lattices and can be implemented in a virtual single-step fabrication process using GLAD. A highly porous film with engineered nanostructure results from the implementation of advanced substrate motion during the deposition, and three-dimensional periodicity required for a photonic crystal can be obtained when a square spiral staircase is fabricated on a tetragonally seeded substrate. We present successful fabrication of three-dimensional square spiral structures along with some examples of the unique capabilities of these nanostructured thin films.