2-pattern photonic crystal and the associated photonic devices are described here. A 2-pattern photonic crystal has a large, complete photonic band gap. It includes a TM sub-structure providing a large TM photonic band gap superimposed on a TE sub-structure providing a large TE photonic band gap. The resulting 2-pattern photonic crystals have complete photonic band gaps larger than 15%. By altering the respective sub-structures, optical devices for different polarizations (TE, TM or both) can be readily designed, and those optical devices can be integrated on the same plane.