Extended-drude model to fit infrared conductivity cuprate laser-ablated films

An "extended-Drude" model, implying a simple form for the self-energy funct ion of the mobile charge-carrier response, has been applied to fitting the infrared and visible reflectivity spectra of simple cuprates. Excellent fit s are obtained in a wide spectral range, from 4 meV to 4 eV, with a very re stricted number of adjustable parameters. The optical conductivity obtained with this procedure is highly different from the Kramers-Kronig transforma tion of reflectivity spectra. The same procedure has been applied to charac terise the infrared conductivity of multi-target laser-ablated films built via intergrowth of YBa2Cu3O7 and MCuO2 (M = Ca, Sr).