FeAs(Se)-layered superconducting compounds under pressure

The recent discovery of superconductivity in various FeAs(Se)-layered structured compounds (F-doped oxypnictide, K-doped BaFe2As2 and FeSe compounds) with significantly high Tc and its large positive pressure dependence at moderate pressure range has stimulated a great interest to the detailed investigations of the structural and electronic properties of this compound under high pressure, in order to understand the underlying mechanism. Recent results of our detailed structural, vibrational and optical spectroscopic measurements will be presented in this talk. These results will help understanding the effect of pressure on the electronic structure and also providing input parameters for various model calculations of this system.