Direct fabrication of terahertz optical devices on low-absorption polymer substrates.

We have fabricated terahertz wire grid polarizer and terahertz bandpass filter devices on high-density polyethylene substrates using simple photolithographic fabrication techniques. The performance of the fabricated devices was measured using a Fourier transform IR spectrometer. Both devices showed good performance in the terahertz frequency range up to 5 THz, in agreement with rigorous coupled-wave analysis (polarizer) and finite-difference time-domain (filter) simulations. Our results successfully demonstrate the use of standard fabrication techniques to produce large-aperture free-standing terahertz optical devices on low-absorption polymer materials with the advantage of low cost using a simple fabrication process. The fabricated polarizer had better than 30 dB extinction ratio at 3 THz. Bandpass filters were demonstrated at three different center frequencies (1.5, 1.8, 2.9 THz) with a 3 dB insertion loss and 2<or=Q<or=7.