A modal technique is used for modeling the problem of light propagation through masks with subwavelength features. Different approaches for the proper treatment of the excitation and the finite window are discussed. Results obtained using the technique are compared to those obtained by the volume integral equation method and the finite difference time domain method. The proposed technique shows very good agreement with both methods as well as significant reduction in the simulation time compared to the finite difference time domain method.
Ismail M. Nassar,
Omar A. Omar,
Aladin H. Kamel,
"Modeling of subwavelength problems using modal techniques," Optical Engineering 51(3), 038001 (23 March 2012). https://doi.org/10.1117/1.OE.51.3.038001