Analysis of axially symmetric diffraction grating

Effective calculation technique for periodic structures is proposed in this paper. The grating possesses a lot of periods and is difficult to be calculated with usual methods. The proposed technique is based on well-known Finite Difference in Time Domain method for Body of Revolution (BOR FDTD). The method implementation for small-scale grating situated in a hollow dielectric waveguide is shown. Mentioned method is developed for structures with lossy dielectric. In order to restrict calculation domain absorbing boundary conditions is provided in the form of Perfectly Matched Layer (PML). Numerical calculations for different gratings are provided, the obtained results are analyzed.