Transformation optics PML for Wood’s anomalies

We proposed an Adaptive Perfectly Matched Layer (APML) to be used in diffraction grating modeling. With a properly tailored co-ordinate stretching depending both on the incident field and on grating parameters, the APML may efficiently absorb diffracted orders near grazing angles (the so-called Wood’s anomalies). The new design is implemented in a finite element method (FEM) scheme and applied on a numerical example of a dielectric slit grating. Its performances are compared with classical PML with constant stretching coefficient.

Related paper

B. Vial, F. Zolla, A. Nicolet, M. Commandré, and S. Tisserand. Adaptive perfectly matched layer for Wood’s anomalies in diffraction gratings. Opt. Express, 20(27), p.28094-28105, Dec. 2012. DOI |http | download

Magnetic field map showing improved absorption in adapted PML for a grazing diffraction order in comparison with classical PML