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Pictured here is a schematic exhibiting an ultra-thin meta-lens created by researchers at Harvard University. The lens is made of titanium dioxide nanofins on a glass substrate. In the schematic, the meta-lens focuses an incident light (penetrating from bottom and propagating upward) to a spot (yellow space) smaller than the incident wavelength.
The researchers have found a way to create the very first planar lens that works very efficiently within the visible spectrum of light. This completely covers the entire range of colors from red all the way to blue. The new lens is able to resolve nanoscale features that are less than a wavelength of light apart from one another using an ultrathin array of teeny waveguides, called a metasurface, that bend light as it passes through. Potential applications for the new technology include wearable optics for virtual reality.Image credit: Peter and Ryan Allen; courtesy of professor Federico Capasso, SEAS/Harvard University; copyright Harvard University
