Do black holes come to mind when you think about singularities? In optics, singularities occur when one or more parameters are undefined, and are also associated with non-intuitive phenomena such as energy backflow and superoscillations. While the vast majority of optical singularities take the form of string-like lines and loops, this paper introduces a technique to engineer singularities belonging to a wider class of shapes. As a demonstration, the authors engineer sheet singularities that have heart-shaped cross-sections, then realize these light fields experimentally using metasurfaces. The technique is also extended from phase singularities to polarization singularities. Singularity engineering to produce structured dark may enable the creation of exotic field configurations with applications in super-resolution microscopy, optical trapping, and remote sensing.
The lead author for this publication is Soon Wei Daniel Lim (Daniel Lim).