Integrated structure of polarization detection in the visible spectrum based on double wire grids

We introduce an integrated polarization detection structure consisting of a photoelectric conversion material, silicon (Si), in the form of a wire grid and an aluminum (Al) wire grid polarizer layer. This structure provides transverse magnetic (TM) polarization absorptivity and an enhanced extinction ratio in the visible spectrum. Finite difference time domain simulations were used to examine the influences of different periods and thicknesses of the Si and Al grid components. The results showed that the absorptivity of TM polarization exceeded 70% in the visible spectrum (a 20% improvement), the absorptivity of transverse electric polarization was reduced by >90%, and the extinction ratio improved by a factor of 33. When the incidence angle is over the range of 0 deg to 30 deg, the absorptivity of TM polarization and the extinction ratio perform well, exceeded 60% and 75. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)