Analysis of finite-sized guided-mode resonant gratings using the fast multipole boundary element method

Guided-mode resonant grating filters are dispersive devices that utilize resonance anomalies. When they are modeled as finite imperfect periodic structures, it is time-consuming to calculate their optical properties precisely, and huge computational memories are needed to accommodate the large analytical domain. This limits the numerical performance, and so existing reports, which use the conventional boundary element method, refer to structures with less than 100 periods. This paper shows that general optical properties and the impact of production error distributions can be calculated for guided-mode resonant grating filters with several hundred periods using the fast multipole boundary element method.