Photoinduced nonlinear optics methods as new methods of monitoring the superconducting films

A new method of monitoring the superconductivity in the Hg-1201 films is proposed using the photoinduced optical second harmonic generation (PISHG). In the present work the experimental PISHG results are presented for the Hg-1201 films deposited on the MgO substrates. We have found that the PISHG is more sensitive compared with the traditional methods (resistivity, magnetic susceptibility, etc.). Using of the pump–probe technique allows obtaining additional parameters of the carrier relaxation responsible for the superconductivity. The proposed method has an advantage compared with the others because they are contactless and non-invasive and give a possibility to detect the phase transitions with higher precision. [Copyright &y& Elsevier]