Picosecond optical response of Tl2Ba2CaCu2O8 and Tl0.5Pb0.5Sr2(Ca0.8Y0.2)Cu2O7 high Tc superconductor films

We have investigated the optical response of 700 nm optically thick Tl2Ba2CaCu2O8 and Tl0.5Pb0.5Sr2(Ca0.8Y0.2)Cu2O7 high Tc superconductor films activated by a few mJ/cm2 laser pulses. We have systematically studied the dependence of optical response on temperature and laser intensity. Fast and slow components can be clearly identified. A 70 ps electric transient has been obtained when activated by a 3.3 mJ/cm2 laser at 80 K or by a 10 mJ/cm2 laser at 50 K.