INFRARED PROPERTIES OF BI2SR2CAN-1CUNOY

Near infrared optical properties such as the complex dielectric constant (epsilon*) and loss function -Im (1/epsilon*) have been measured by spectroellipsometry for Bi2Sr2CaCunOy single crystal and Bi2Sr2CuOy and Bi2Sr2Ca1CunOy c-axis oriented films made by the laser ablation method. In this region this is the first time when epsilon* is obtained directly without using Kramers-Kronig transformation. The frequency ofoptical plasmon is obtained as 8200cm-1 from a zero point of epsilon-1 for both superconductive Bi2Sr2CaCunOy single crystal and film. There is a clear difference of peak position of -Im (1/epsilon*) between a superconductive and a non-superconductive sample.