The depolarization effect in the problem of diffraction on a grating consisting of thin semi infinite chiral slabs

The diffraction of a normally incident plane wave by a grating consisting of thin semi infinite chiral slabs is considered. The chiral slabs are simulated by the appropriate first-order transition boundary conditions. The problem is simplified by decoupling E_z and H _z components via a similarity transformation. Then, the problem is reduced to the scalar Riemann-Hilbert problems and solved in an explicit form. The expansion of the diffracted field in terms of the plane waves is obtained and the depolarization effect is discussed