Researchers have revealed the ‘perfect’ lens.
Known as a metalens, it is a flat surfaces that use nanostructures to focus light.
This means the bulky, curved lenses currently used in optical devices could be replaced with a simple, flat surface.
Known as a metalens, it is a flat surfaces that use nanostructures to focus light. This means the bulky, curved lenses currently used in optical devices could be replaced with a simple, flat surface
However, until now these metalenses have remained limited in the spectrum of light they can focus well.
Researchers at Harvard have now developed the first single lens that can focus the entire visible spectrum of light — including white light — in the same spot and in high resolution.
The breakthrough could lead to dramatically thinner camera lenses, and new higher resolution VR headsets.
‘Metalenses have advantages over traditional lenses,’ said Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS and senior author of the research.
‘Metalenses are thin, easy to fabricate and cost effective.
‘This breakthrough extends those advantages across the whole visible range of light.
‘This is the next big step.’
![The breakthrough could also replace the bulky optical lenses found in VR headsets](https://i.dailymail.co.uk/i/pix/2018/01/01/22/47B0076E00000578-5227107-image-a-4_1514846019333.jpg)
The breakthrough could also replace the bulky optical lenses found in VR headsets
The research is published in Nature Nanotechnology.
Focusing the entire visible spectrum and white light – combination of all the colors of the spectrum — is so challenging because each wavelength moves through materials at different speeds.
Red wavelengths, for example, will move through glass faster than the blue, so the two colors will reach the same location at different times resulting in different foci.
This creates image distortions known as chromatic aberrations.
Cameras and optical instruments use multiple curved lenses of different thicknesses and materials to correct these aberrations, which add to the bulk of the device.
The metalenses use arrays of titanium dioxide nanofins to equally focus wavelengths of light and eliminate chromatic aberration.
‘Using our achromatic lens, we are able to perform high quality, white light imaging. This brings us one step closer to the goal of incorporating them into common optical devices such as cameras,’ said Alexander Zhu, co-author of the study.
Next, the researchers aim to scale up the lens, to about 1 cm in diameter.
This would open a whole host of new possibilities, such as applications in virtual and augmented reality.