Dual-band polarized optical switch with opposite thermochromic properties to vanadium dioxide

Abstract

A dual-band polarized wavelength-selective optical switch whose thermochromic transmission property is opposite to VO2 itself is proposed. The switch shows a low and high transmittance during phase transition from insulating VO2 to metallic VO2, respectively. The multi-mode coupled circuit model is employed to calculate and tailor the operating frequency of the switch in xz sections for TM waves and yz sections for TE waves. The switch exhibits a transmittance difference of more than one order of magnitude between “on” and “off” modes when the structure is same in the x and y directions under circularly polarized light incidence. For the condition that the structure is not same in the x and y directions, thermochromic transmittance becomes polarization-dependent. By superimposing two polarization states, a dual-band as well as broadband thermochromic transmission property is obtained. The mechanisms of suppressed and enhanced transmission lie in the excitation of MPC and MPV2, respectively. This study may have theoretical guiding significance for design and tailoring of metamaterials with wavelength-selective broadband thermochromic transmission property and potentially apply in active filters and architectural energy-efficient glass.