Diffraction of 3-D Gaussian Beam with Circular Symmetry of the Field Space Distribution by Permeable Screens at Small Angles of Incidence

The problem of scattering of 3-D Gaussian beam incident at a small angle onto a doubleperiodic magnetodielectric slab has been formulated and solved. The new formulas for incident and scattered 3-D Gaussian beam fields in the form of single integrals have been derived. These allow reducing the time spent upon numerical calculations of the incident and scattered beam fields and improving their accuracy. The calculations of the 3-D Gaussian beam obliquely incident onto magnetodielectric slab with the derived formulas are illustrated in figures presented in the paper.