Efficient light control: Meta-optics replace conventional lenses

Summary

Advanced light control: A laser beam hits a meta-grating that directs the light waves even at steep incidence angles, thus enabling new optical applications. Credit: Maryna Leonidivna Meretska Conventional curved lenses, which direct light by refraction in glass or plastic, are often bulky and heavy, offering only limited control of light waves. Metasurfaces, in contrast, are flat and consist of an array of tiny structures known as meta-atoms. Meta-atoms influence light at a subwavelength scale and thus allow for highly precise control of the phase, amplitude, and polarization of light. "Using metasurfaces, we can influence the temporal shift, intensity, and direction of oscillation of light waves in a targeted way," says Dr. Maryna Leonidivna Meretska, Group Leader at KIT's Institute of Nanotechnology. "Thanks to its multiplex control capabilities, i.e., the simultaneous and targeted influencing of various parameters, a single metasurface can replace multiple optical components. Thus, the size of the optical system can be reduced without affecting its performance." Production will also be simpler, "Metasurfaces can be manufactured using advanced lithography and etching technologies from the semiconductor industry, making scalable production possible," says Meretska. Meta-grating with a fourfold increase in efficiency At Hannover Messe, which begins Monday, March 31, Meretska and her team will present an optical diffraction meta-grating that was made using special KIT manufacturing equipment. Diffraction gratings are essential optical components that can be used in various industrial applications, such as spectroscopy, telecommunications, and laser systems. Usually, the efficiency of diffraction gratings decreases sharply as the angle of incidence of the light increases. The meta-grating developed at KIT is four times more efficient than conventional systems. "Our meta-grating offers unprecedented control of light under challenging conditions. This represents a sign...