Open AccessAsymptotic model for finite-element calculations of diffraction by shallow metallic surface-relief gratings
Author(s) -
Cinthya Rivas,
Manuel Solano,
Rodolfo Rodrı́guez,
Peter Monk,
Akhlesh Lakhtakia
Publication year - 2016
Publication title -
journal of the optical society of america. a, optics, image science, and vision./journal of the optical society of america. a, online
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.803
H-Index - 158
eISSN - 1520-8532
pISSN - 1084-7529
DOI - 10.1364/josaa.34.000068
Subject(s) - grating , planar , diffraction , diffraction grating , optics , finite element method , surface (topology) , materials science , computer science , physics , geometry , mathematics , computer graphics (images) , thermodynamics
We have formulated an asymptotic model for implementation in the finite-element method to calculate diffraction from a planar multilayered structure having a shallow surface-relief grating. The thin grating layer containing the shallow grating is replaced by a planar interface with transmission conditions that differ from the standard continuity conditions, thereby eliminating the necessity of representing the grating layer by a fine mesh. The parameters defining the shallow surface-relief grating are thereby removed from the geometry to the transmission conditions. Adoption of the asymptotic model will considerably reduce the computational cost of optimizing the grating shape because there is no need to re-mesh at every optimization step.