An ultrafast laser micromachined broadband terahertz frequency selective surface

The purpose of this paper is to focus on the frequency selective surface (FSS) filter structure which exhibits a broadband frequency response operating in the terahertz (THz) frequency regime. The achievement of the broadband frequency response has been accomplished by means of only invoking the FSS structure excluding the presence of a ground plane and also excluding the multilayered FSS technique. The FSS filter is simulated using CST Microwave Studio. This simulation has been carried out using Teflon as the substrate which is a dielectric over which the conductive material gold with a thickness of $$2\,\upmu \hbox {m}$$ is coated in which the FSS filter structure is designed with periodic hexagonal aperture unit cells. The structure of the proposed frequency selective surface filter helps in achieving a broadband frequency response with a bandwidth of 300 GHz centred at 0.36 THz. The designed FSS structure is a bandpass filter and it exhibits the most imperative properties of angle resolvability and polarization insensitivity. The fabrication of the same has been carried out using the laser micromachining process.