Broadband THz filters for THz sensing devices

We propose a broadband filter using multi-layered frequency selective surfaces (FSS) for terahertz (THz) sensing devices. These types of filter windows are required to be placed in front of THz sensors to increase signal-to-noise ratio and reduce sensor sensitivity to mid IR and visible light. The FSS filter is simulated using polyethylene dielectric layers with fan shaped metal slots. Simulations show excellent flat band-pass response and a sharp out-of-band frequency response in 1–3 THz frequency range, centered at 1.95 THz. The −3 dB bandwidth achieved from this design is 1 THz (1.5THz–2.5THz).