Terahertz Filters and Polarizers Using 2-D Subwavelength Hole Arrays

The filtering and polarizing of terahertz waves are essential for various terahertz applications. Here, we use two-dimensional (2-D) rectangular subwavelength hole arrays (SHAs) to achieve efficient wave filtering and polarizing in the terahertz region. The transmissive filtering is obtained by exciting the specified resonant modes within the subwavelength holes. With the same basic physics, the elliptic-to-linear and linear-to-elliptic (linear-to-circular) polarization conversions are successfully achieved by properly arranging the 2-D SHAs. Thanks to its easy realizability, these 2-D SHAs can promisingly be developed as efficient terahertz wave filters and polarizers for practices.