Guiding terahertz radiation

University of Utah engineers have designed stainless steel foil sheets with patterns of perforations that successfully served as wire-like waveguides to transmit, bend, split and combine terahertz radiation.

This February, British researchers reported that they used computer simulations and some experiments to show that indentations punched across an entire sheet of copper-clad polymer could hold terahertz radiation close to the sheet's surface. That led them to conclude the far-infrared light could be guided along such a material's surface.

But the London researchers did not actually manipulate the direction the terahertz radiation moved, such as by bending or splitting it.

'We have demonstrated the ability to do this, which is a necessary requirement for making terahertz guided-wave circuits,' said Ajay Nahata, an associate professor of electrical and computer engineering at Utah.

To do so, the researchers used pieces of stainless steel foil about 4 inches long, 1 inch wide and 625 microns thick. They perforated the metal with rectangular holes, each measuring 500 microns by 50 microns. The rectangular holes were arranged side by side in three different patterns to conduct the terahertz radiation.