OPTICAL DIFFRACTION OF FOCUSED SPOTS AND SUBWAVELENGTH STRUCTURES

We have developed a numerical diffraction tool for cases in which the incident field is a focused spot and the diffracting structure is a si ngle structure or an aperiodic surface. Our approach uses the integral formulation to solve Maxwell's equations and is different from previo usly published methods in its choice of basis function. We compared nu merical results with experimental measurements of the far-field intens ity for a focused spot incident on an aluminum grating, and the compar ison was favorable. Finally, we predict the diffraction behaviour the reflected signal for this format has a strong dependence on the polari zation of the incident light. (C) 1997 Optical Society of America.