The employment of THz radiation, i.e. radiation with frequencies falling between the microwaves and infrared domains, is arousing an ever-increasing interest in the last decade. Thanks to its invaluable features, such as transparency to the most part of the materials, negligible ionizing energy and availability of high frequency carriers, this technology is penetrating in lots of areas, spanning from medical care and homeland security to cultural heritage and telecommunication systems. However, the lack of reliable devices devoted to THz wave handling still has to be properly addressed.