MIT has developed a camera ‘metalens’ which can shift focus without tilting or moving, opening the door for miniature zoom lenses for drones, mobile devices and night vision goggles.
The tuneable ‘metalens’ can focus on objects at multiple depths without changes to the physical location or shape of the lens, using a transparent ‘phase-changing’ material that can rearrange its atomic structure and change the way the material interacts with light after a heating phase.
MIT researchers etched the material’s surface with tiny patterned structures that work together as a “metasurface”, retracting or reflecting light. As the material’s property changes, the optical function of the metasurface changes accordingly, with the atomic structure changing after heating and redirecting light to focus on a more distant object.
The ‘metalens’ can tune its focus without the need for mechanical elements and could allow miniature heat scopes to be developed for drones, tiny thermal compact for mobile devices and less bulky night-vision goggles.
Tian Gu, research scientist, MIT’s Materials Research Laboratory, commented: “Our result shows that our ultrathin tunable lens, without moving parts, can achieve aberration-free imaging of overlapping objects positioned at different depths, rivaling traditional, bulky optical systems.”