Artificial Materials for Terahertz Applications

Artificial materials are three dimensional surfaces which can manipulate, focus and filter electro-magnetic radiation. These materials provide engineered properties which may be difficult to obtain or even unavailable in nature. At Durham University, we design, fabricate and test materials which can operate in the terahertz region of the electromagnetic spectrum (typically 300 GHz to 10 THz). The wavelength of the incident radiation determines the typical feature size required in the artifi-cial material. Micromachining which adopts techniques from the integrated circuit industry is well suited to the development of terahertz based artificial materials (where 1 THz = 300 microns). 2. Why? In recent years, the terahertz region of the electromagnetic spectrum has received considerable in-terest in the literature. Traditionally this region has been largely ignored when compared to the microwave and infrared regions that bound it. However, various applications for terahertz technol-ogy are emerging. These include the detection of hidden explosives and materials through combined imaging and spectroscopy techniques. Further applications have been found in biological sensing and manufacturing process control. Terahertz microscopes, which probe with a subwavelength res-olution are under development with the ultimate aim of performing spectroscopy on single cells. The development of new THz generation techniques and time domain spectroscopy has aided the progression of the technology. However, many of the peripheral elements, which are used in other regions of the electromagnetic spectrum, such as lenses and filters are less commonplace at THz frequencies