Design of terahertz wire-grid polarizer of laminated parallel plates on cyclo olefin polymer films for high extinction ratio less than 10−6

This paper presents the analysis and design of a wire-grid polarizer comprising laminated parallel plates with a high extinction ratio less than 10^-6 over the range 0.1 to 1.91 THz. One waveguide is extracted with the periodicity of the wire-grid and is analyzed using the mode matching method. Cyclo olefin polymer film which has low loss in the terahertz frequency band is used for a supporting substrate in order to prevent the reduction in transmittance of the TM mode. The copper parallel plates were fabricated on cyclo olefin polymer films by etching. The mode matching method is used to predict the TM mode transmittance and analysis results are compared to measured results. The loss of the TM mode transmittance can be improved by the reduction of the film area. The TE mode transmittance is too small to distinguish from noise in the measurement system.