Mechanically tunable photonic crystal structure

Abstract
We report a tunable nanophotonic device concept based on flexible photonic crystal, which is comprised of a periodic array of high-index dielectric material and a low-index flexible polymer. Tunability is achieved by applying mechanical force with nano-/microelectromechanical system actuators. The mechanical stress induces changes in the periodicity of the photonic crystal and consequently modifies the photonicband structure. To demonstrate the concept, we theoretically investigated the effect of mechanical stress on the anomalous refraction behavior and observed a very wide tunability in the beam propagation direction. This concept provides a means to achieve real-time, dynamic control of photonicband structure and will thus expand the utility of photonic crystalstructures in advanced nanophotonic systems.