We rigorously analyze the optical singularities and power flux in the near-field region of the novel superlenses reported in [ Science 317, 927 (2007) ] For this purpose, we derive near-field expressions and a general criterion to classify the optical singularities in the vacuum, which are valid when the (s- or p-polarized) electromagnetic fields are generated by any planar field distribution with Cartesian or azimuthal symmetry. Such general results are particularized to the superlenses [ Science 317, 927 (2007) ], for which we identify a sequence of optical vortices and saddles that arise from evanescent-field interference. While the saddles are always located around the focal region, the vortex locations depend on the source field. The features of the topological connection between vortices and saddles are also discussed.
© 2008 Optical Society of America
Original Manuscript: August 4, 2008
Revised Manuscript: September 15, 2008
Manuscript Accepted: September 17, 2008
Published: October 30, 2008
Manuel Perez-Molina, L. Carretero, P. Acebal, and S. Blaya, "Optical singularities and power flux in the near-field region of planar evanescent-field superlenses," J. Opt. Soc. Am. A 25, 2865-2874 (2008)