title: Expansion of the difference-field boundary element method for numerical analyses of various local defects in periodic surface-relief structures.
abstract: We expand the difference-field boundary element method (DFBEM) to calculate wave scattering from a variety of local periodic structure defects. The DFBEM is a numerical method for simulating the diffraction caused by a periodic surface-relief structure with a defect. Although it is more efficient than conventional techniques such as the finite-difference time-domain (FDTD) method, the original DFBEM is limited to projection defects. Here, we derive the integral equations and expressions for crack and buried-pillar defects, and also demonstrate some numerical analyses, validating the results by comparison with results from the FDTD method and the dielectric interface boundary conditions.
authors.forename: Jun-ichiro
authors.initials: J
authors.lastname: Sugisaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Yasui
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirayama