Woodpile-type photonic crystals with orthorhombic or tetragonal symmetry formed through phase mask techniques.

This paper simulates the photonic band structure in face-centered-orthorhombic and face-centered-tetragonal woodpile-type photonic crystals and shows the fabrication feasibility of these crystals with phase mask based holographic lithography. The experimental demonstration on SU-8 photoresist indicates that a single optical element can replace a complex optical setup for the holographic fabrication of woodpile-type photonic crystals. Photonic band gap calculation predicts the existence of full band gap in these crystals. Optimum band gap sizes are studied for crystals formed under various experimental conditions.\ud \u