This research is concerned with a study of the optical properties of as-grown and artificially-structured high-temperature superconductors over the far-infrared through ultraviolet wavelength range. The role of the superconducting layer thickness and of interlayer coupling will be studied through measurements of yttrium-barium-cuprate/praseodymium-barium-cuprate multilayer systems. Measurements of a wide variety of other high temperature superconductor materials will address issues such as the superconducting energy gap and the nature of the non-Drude absorption that occurs in the midinfrared range. The project represents a collaboration between the University of Florida, where most of the infrared measurements will be made, and Bell Communications Research, where much of the sample preparation will be carried out.