Beam manipulating by graded photonic crystal slab made of dielectric elastomer actuators

Abstract

The focusing lens and beam-steering device are implemented using two-dimensional graded photonic crystals with dielectric elastomer tube array embedded in air background. The gradient refractive index could be adjusted by varying the applied voltage on the dielectric elastomer tube so that the tube radius would change accordingly, which consequently alters the filling factor of the constituent material in photonic crystals, and the photonic dispersion band can be modulated. The finite element method is employed to simulate the electromagnetic wave propagation inside the designed device and analyze both the tunable focusing properties and beam-deflecting behavior. The implementation of the proposed device is validated within the lowest band. It is concluded that the proposed innovative device could easily accomplished the applications of focusing and steering electromagnetic fields with nonuniform applied voltage profiles.