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The use of laser ablation of a thin metal film, which allows for rapid prototyping of various free-standing terahertz devices, is reported. The technique will provide a simple way to fabricate devices without complicated photolithography procedures. This could be a solution for a multitude of new optical elements for the terahertz regime. The fabricated samples are free-standing films and, hence, benefit from the absence of a supporting dielectric substrate, which could induce dispersion, losses or alter the reflection properties. Three devices are demonstrated: a wire-grid polariser, a polarisation converter and bandpass filters, and their performance is characterised.

Miniaturised CPW bandstop filters based on complementary spiral resonators etched into a single metal layer are demonstrated. The resulting electrical size is λg/44. Hence, a high degree of miniaturisation is achieved. These filters could hold high potential for applications where miniaturisation and compatibility with planar technology are key issues.

Complementary asymmetric split resonators (CASRs), which feature a sharp passband response are proposed. The design is derived by applying the Babinet principle to asymmetric split resonators (ASRs). The complementary nature of the CASR and the ASR structures is discussed in detail with regard to the transmission and reflection response as well as to the electric and magnetic field distributions.