Numerical calculation of electromagnetic scattering properties and structural parameters of periodic structures is disclosed. A reflection coefficient has a representation as a bilinear or sesquilinear form. Computations of reflection coefficients and their derivatives for a single outgoing direction can benefit from an adjoint-state variable. Because the linear operator is identical for all angles of incidence that contribute to the same outgoing wave direction, there exists a single adjoint-state variable that generates all reflection coefficients from all incident waves that contribute to the outgoing wave. This adjoint-state variable can be obtained by numerically solving a single linear system, whereas one otherwise would need to solve a number of linear systems equal to the number of angles of incidence.
|Patent number||US8645109 (B2)|
|Publication status||Published - 4 Feb 2014|
Dirks, R., Setija, I. D., Kraaij, van, M. G. M. M., & Beurden, van, M. C. (2014). Methods and apparatus for determining electromagnetic scattering properties and structural parameters of periodic structures. (Patent No. US8645109 (B2)).