Eurekalert March 28, 2019
Metalenses are currently limited by their static and their complex and expensive fabrication and for imaging operations such as zooming and focusing. Most metalenses cannot adjust their focal spots without physical motion as the building blocks of these lenses are made of hard materials that cannot change shape once fabricated. Researchers at Northwestern University built a flat and versatile lens out of an array of cylindrical silver nanoparticles and a layer of polymer patterned into blocks on top of the metal array. By simply controlling the arrangement of the polymer patterns, the nanoparticle array could direct visible light to any targeted focal points without needing to change the nanoparticle structures. The scalable method enables different lens structures to be made in one step of erasing and writing, with no noticeable degradation in nanoscale features after multiple erase-and-write cycles. This new device offers promise for high-resolution imaging in devices from small wide-angle cameras to miniature endoscopes…read more. TECHNICAL ARTICLEÂ
During a single imaging session, the device can evolve from a single-focus lens to a multi-focal lens that can produce more than one image at any programmable 3D position. Credit: Northwestern University