Application of the theory of coupled waves for analysis of inclined reflectors in optical waveguides

A new method for analysing the transmission and scattering of the guided TE mode in an inclined reflector located in an optical waveguide is proposed and studied. The reflection of an inhomogeneous optical beam from the inclined reflector is described semi-analytically for the first time by using the theory of coupled waves and taking into account the interrelation and transformation of energy between all the waves of the discrete and continuous spectra of the optical 2D-waveguide (even and odd guided, radiation, and evanescent waves). The results of calculations of the propagation of light through the inclined reflector in the form of a thin (10 — 500 nm) homogeneous strip obtained by our method and by the finite difference time domain (FDTD) method are in excellent quantitative agreement. The calculation rate of our method considerably (by one — two orders of magnitude) exceeds that of the FDTD method and our method has a better accuracy.