Strong mid-infrared transient absorption of one-dimensional copper oxide Sr/sub 2/CuO/sub 3/

Summary form only given. Electron correlation effects, which have attracted much interest after the discovery of high temperature superconductivity and manifest themselves in anomalous transport and/or magnetic phenomena, can also be found in optical properties of strongly correlated electron systems. In particular, we have recently discovered strong optical nonlinearity of one-dimensional Mott insulator Sr/sub 2/CuO/sub 3/ in near-infrared (IR) region. Importantly, the material shows picosecond recovery of the optical transparency making it possible to employ this material in ultrafast all-optical switching devices. However, the relaxation dynamics of the optical excited states is still unclear. To investigate the relaxation process, we performed pump-probe transmission measurements in mid- and near-IR region of 0.1-1 eV. We have found anomalously strong transient absorption band at 0.3 eV.