Electromagnetic Vector Monochromatic Diffraction Fields and Fields of Charges in Media

Monochromatic electromagnetic fields are considered inside an arbitrarily chosen volume both in homogeneous and inhomogeneous media. Formulas for the fields in the selected volume are obtained using the vector Green’s function of the medium. Two forms of the vector Green’s function are found for homogeneous media. The Kirchhoff and Kirchhoff–Kottler vector formulas for the problem of diffraction by an aperture in an opaque screen are obtained. Because of the use of the vector Green’s function, the Kirchhoff–Kottler formula is obtained directly, without using additional assumptions.