Singularity removal in optical instruments without reflections or induced birefringence

Abstract

The refractive index profiles for some optical instruments such as Eaton lenses or invisible spheres include point singularities where the refractive index approaches infinity. A photorealistic visualization of imperfectly approximating such a singularity with realistic materials is presented and a method involving replacing regions near optical singularities with nonsingular birefringent materials is expanded upon in order to allow transmutations without introducing surface reflections when combining rescaling and transmutation operations. A new method, not derivable through transformation optics, for removing point singularities in optical instruments without introducing birefringence is also introduced. Both methods may prove useful in the design of gradient index optical devices. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.