RAY OPTICAL ANALYSIS OF A PLANE-WAVE SCATTERING BY AN ECHELETTE DIFFRACTION GRATING

The two-dimensional problem of scattering of a nearly grazing plane wa ve by a diffraction grating, echelette with right angle is considered for the case of high-frequency approximation (when period of grating i s far greater than the wavelength). The two classical boundary conditi ons, transverse electric (TE) and transverse magnetic (TM) cases in el ectromagnetic theory, are implied. The ray optical solution of the pro blem (short-wave asymptotic result) is derived on the basis of the met hod of summation of multiple diffracted fields, which is well known in the geometric theory of diffraction. Numerical results are presented and compared with calculations based on the rigorous method of integra l equation.