Rigorous diffraction theory is applied to compute the electromagnetic fields in the neighborhood of polygonal obstacles of three- and two-dimensional shape, including two-dimensional gratings. For obstacles such as a rectangular depression, a polygonal groove, or an array of grooves present in a metallic substrate, we calculate and measure significant departures from what a scalar diffraction approach would predict as soon as the width of the obstacle becomes smaller than one wavelength. For such widths, it is shown that the apparent depth of a groove can be smaller or larger than the geometrical depth, depending on the polarization of the incident light and on the optical constants of the substrate.
© 1979 Optical Society of AmericaFull Article | PDF Article
D. S. Marx and D. Psaltis
J. Opt. Soc. Am. A 14(6) 1268-1278 (1997)
O. Mata-Mendez and J. Sumaya-Martinez
J. Opt. Soc. Am. A 14(9) 2203-2211 (1997)
D. N. Qu, X. Yuan, and R. E. Burge
J. Opt. Soc. Am. A 10(11) 2317-2323 (1993)