Optical vortices detected in the near-field heart diffraction

Abstract

Diffraction of light through a heart-shaped slit in the near-field region generates a caustic surface at its evolute. Due to the phase of the light forming its caustic surface, optical vortices were suspected to reside inside it. To prove this claim, two simulations were done. One obtains the interference of its diffraction pattern with a tilted plane wave and the other locates the intersection of zeros of the real and the imaginary parts of its diffraction pattern. Both methods were able to verify the presence of several optical vortices in the circular caustic of a near-field heart diffraction pattern.