Reformulation of the eigenvalue problem in the Fourier modal method with spatial adaptive resolution.

The Fourier modal method equipped with the concept of adaptive spatial resolution (FMMASR) is shown to be naturally more stable than the classical Fourier modal method toward spurious modes that appear with metallic structures. It is demonstrated that this stability can be further improved by reformulating the eigenvalue problem of the FMMASR. (C) 2009 Optical Society of America