Deducing light scatter from AFM measurements

For the numerical prediction of the scattering behavior of arbitrary surfaces the use of a multi pole mthod is a potentially successful way. One reason is its direct addressing of the free space problem, which is primarily not possible with methods such as FEM. For purposes of verification with a reduced set of degrees of freedom the multi pole method is applied on gold plated blazed optical gratings, which are described as surfaces with one-dimensional height function and ideally conductive boundary, leading to a 2D-problem with a simplified matching of the boundary conditions. The geometry is deduced from AFM measurements, numerical results are compared with measurements. An outlook is given on further extensions of the multipole method to 3D-problems with arbitrary boundary conditions such as dielectric layers with losses.