from the picture-that! dept.
Producing the perfect color images we need and love often requires multiple, heavy lenses so that each color focuses in exactly the same plane. Now Penn State engineers have developed a new theory that solves the problem using a single thin lens composed of gradient index materials and metasurface layers to properly direct the light.
"If we want high performance optical systems, then we have to overcome material dispersion," said Sawyer D. Campbell, assistant research professor in electrical engineering. "If we don't, we get smeary colors, which significantly degrades image quality."
Single apochromatic lenses -- ones that properly focus the three colors red, blue and green -- that have less curvature and are thinner and lighter could improve cell phone cameras and allow manufacture of thinner cell phones. They also could make lighter, better body cameras, helmet cameras, sniper scopes, thermal imaging devices and unmanned aerial vehicles or drones. In essence, anything that uses lenses to image could be made simpler and lighter.
J. Nagar, S. D. Campbell, D. H. Werner. Apochromatic singlets enabled by metasurface-augmented GRIN lenses. Optica, 2018; 5 (2): 99 DOI: 10.1364/OPTICA.5.000099