Strain-tunable photonic band gap crystals

We have designed a two-dimensional strain-tunable photonic band gap crystal by distorting the symmetry of the crystal from a regular hexagonal to a quasihexagonal lattice by means of field driven strain using a piezoelectric material. Calculations predict that the original high symmetry energy bands split up into several strained energy bands depending on the magnitude and direction of the strain. In the proposed structures, we show that 2% (3%) shear strain can be used to tune $\text{∼52\%}$ (73%) of the original undistorted absolute band gap of a two-dimensional photonic band gap crystal. These device structures can be used for optical switching and modulation.