THz artificial dielectric isolator

We experimentally demonstrate an isolator suitable for the THz spectral regime. The isolator is designed by combining a polarizing beamsplitter with a quarter-wave plate, both based on the same artificial-dielectric technology. The artificial-dielectric medium comprises of a stack of 30 μm thick metal plates that form an array of parallel-plate waveguides. The isolator exhibits an isolation of 52 dB with an insertion loss less than one dB, at a frequency of 0.46 THz, which rivals the performance of commercially available Faraday isolators for optical wavelengths.