Ultrafast optical response has been investigated using fs laser system on a perovskite-type cobalt oxide, La1.5Sr0.5CoO4. After the photoirradiation at room temperature, the time profile of relative change of reflectance (ΔR/R) shows a sudden change within the pulse duration (≈ 150 fs) and decays with a lifetime of ≈ 330 fs. The sign of ΔR/R after the photoexcitation is positive in the mid-infrared region (at 0.50 eV) while negative in the visible energy region (at 2.0 eV), implying photoinduced change of the electronic structure after the photoexcitation.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)