Electromagnetic diffraction of light focused through a stratified medium

We consider the focusing of light by a high-aperture lens into a stratified medium. The solution is based on our previously obtained results [J. Opt. Soc. Am. A 12, 325 (1995)], where we represented the illumination incident upon a plane interface between media with mismatched refractive indices as a sum of plane waves. The present solution is obtained in terms of plane waves, and it satisfies Maxwell’s equations. The diffraction integrals are obtained in a form that is readily computable. We present numerical examples for some practical cases.