9403894 Tanner Technical abstract: The optical properties-in both normal and superconducting states-of high temperature superconductors will be studied at far infrared-ultraviolet frequencies. In the normal state, the research will focus on the nature of the non-Drude mid infrared absorption, on the lifetime and interaction of the charge carriers, and on the anisotropy of the quasi-two-dimensional copper oxide layers. In the superconducting state, the research will focus on issues of the superconducting energy gap, on possible anisotropy of the gap, and on the lifetime of quasiparticle excitations. Non-technical abstract: Detailed investigation of the optical properties of the high temperature superconductors is essential for a complete understanding of these very novel materials. By varying the wavelength of the light from the long-wavelength infrared to the ultraviolet, information about the motion of the charge carriers-in both the normal and the superconducting state of theses materials- will be learned. This information may contribute to understanding the superconductivity in these materials and will help to characterize their usefulness for potential applications such as in microwave circuits and infrared sensors. ***
