Method of frustrated total reflection in spectroscopy of surface polaritons in almost perfectly conducting metals

The standard technique for surface polaritons excitation by a prism coupling in Otto configuration is applied for investigation of almost perfectly conducting (pec) metals like tantalum irradiated by a collimated He-Ne laser radiation (*l 0 = 632.8 nm). In pec metals the imaginary part of the relative dielectric permittivity (e'') is quite larger than the modulus of the real part of the same quantity (e' < 0, e'' >>