Broadband and polarization-selective optical switch in infrared spectrum based on SMT materials

A new design of optical switch composed of a vanadium dioxide(VO2) thin film and embedded sub-wavelength metallic gratings was proposed. The numerical calculations of the device performance were carried out using the Finite Element Method (FEM). This design exhibited broadband and polarization selective all-optical switching effects in the near-infrared spectrum. The embedded gratings enhanced the extinction ratio of the VO2 film, and achieved high extinction ratio in sub-wavelength device size. The optical properties of the proposed design depended little on the incident angle. In addition, the transmittance and absorbance can be tuned by the geometric parameters. The device has great potential usages as the infrared spectrum is of great important both in optical communication and computering, and optical imaging in military reconnaissance and industrial non-destructive detecting.