MANIFESTATION OF SUPERCONDUCTING GAP SYMMETRY IN THE OPTICAL-SPECTRUM

The manifestation of the superconducting gap symmetry in optical spect ra at frequencies omega much-greater-than DELTA/h corresponding to int erband transitions is investigated. The problem is treated in the fram ework of the BCS model with mixed sd-wave pairing. The characteristic structure of the imaginary part of the dielectric function depending o n the symmetry of the superconducting order parameter is obtained. The cases when the imaginary part of the dielectric function has a two-pe ak structure near the Fermi level are considered. In these cases compl ete information about the superconducting order parameter may be obtai ned from the difference optical spectra extracted from femtosecond las er spectroscopy data.