Nanowerk July 13, 2021
Optical singularities, which appear completely dark, typically occur when the phase of light with a specific wavelength, or color, is undefined. Researchers at Harvard University have developed a new way to control and shape optical singularities. The metasurface tilts the wavefront of light in a very precise manner over a surface so that the interference pattern of the transmitted light produces extended regions of darkness. Their approach allows precise engineering of dark regions with remarkably high contrast. Engineered singularities could be used to trap atoms in dark regions and improve super high-resolution imaging. As darkness has no diffraction limit it can interact with particles over length scales much smaller than the wavelengths of light. This could be used to provide information on not only the size and the shape of the particles but their orientation as well. Engineered singularities could extend beyond waves of light to other types of waves. It is possible to engineer dead zones in radio waves or silent zones in acoustic waves. The research points to the possibility of designing complex topologies in wave physics beyond optics, from electron beams to acoustics…read more. Open Access TECHNICAL ARTICLEÂ
Intersection topologies of zero-isosurfaces that form optical singularities. Credit: Nature Communications volume 12, Article number: 4190 (2021)Â