A 100-Fold Improvement in Lithography Resolution Realized with a 150-Year-Old “Perfect Imaging” System

Juan Carlos Miñano and Dejan Grabovičkić
Cedint Polytechnic University of Madrid

The idea of "perfect imaging", that is a resolution less than the wavelength of light producing the image, was first proposed in the mid-19th century by famed Scottish physicist James Clerk Maxwell. For the next 150 years, it was widely believed that such was impossible due to the fact that light diffracts around points that are the same size or smaller in wavelength. Then, in 2009, Ulf Leonhardt, of the University of St. Andrews in Scotland, theoretically analyzed the phenomenon and demonstrated its focus was not restricted by the diffraction limit.

A research team at the Cedint Polytechnic University of Madrid used simulation to demonstrate Leonhardt’s proposal and prove that diffraction limits can be surpassed. The team proposed using a device to do this, which they called a spherical geodesic waveguide (SGW).

Using COMSOL Multiphysics and the RF Module, the research team was able to demonstrate that these SGWs could be manufactured for certain applications such as microwaves. Their next goal is to design a dielectric SGW that will work in the visible spectrum.

Results of the transmitted power in the SGW as a function of the frequency for different drain port positions (the corresponding shift, expressed as a fraction of the wavelength, on the inner sphere of the SGW between the drain port center and the source port antipode has been used for labeling). A strong drop in the power for a small displacement of the drain port indicates super-resolution property of the SGW.