This paper presents an analytical theory of resonance diffraction in the conical mount. The resonance is caused by plasmon polariton excitation via diffraction from a high reflecting shallow grating. The dependence of polarization, intensity, and phase of specular and resonance waves on the parameters of the problem is presented in explicit form and examined for arbitrary polarization of the incident wave as a function of the angle of incidence and the grating period, orientation and depth. The results obtained enable us to indicate gratings with specific properties, for instance, gratings, ensuring transformation of arbitrarily polarized incident wave into the linearly polarized specular wave. The properties of two-dimensional transformation matrix relating polarization amplitudes of the incident and the specular reflected waves are analyzed. It is shown that the transformation matrix is antisymmetric (in accordance with the reciprocity theorem) for an arbitrary grating profile in the main approximation. The comparison of the results obtained shows remarkable agreement (without any parameters fitting!) with data of the polarization conversion experiments. Both concrete results and the approach presented may be of use in constructing gratings with the predetermined parameters and, therefore, in solving problems of designing optical devices selective with respect to the polarization, wavelength, and orientation.

• Received 18 April 2001

DOI:https://doi.org/10.1103/PhysRevB.65.195406