I won’t pretend to understand nanotechnology but I am curious to know more about an intriguing technology that could revolutionize lens optics.

Imagine a future where eyeglasses are made with lenses thinner than a sheet of paper and with no color dispersion and no time-consuming surfacing or polishing. Currently under development are flat lenses made of “pixels” or “meta-atoms.” The flat meta-lenses that Columbia Engineers have developed are fabricated with a 2-D planar fabrication technique similar to that used to fabricate computer chips but simpler. Computer chips use multiple layers while the flat meta-lenses only use one layer of nanostructures. The lead researcher Nanfang Yu, associate professor of applied physics, explains how the flat meta-lenses manage light. “The beauty of our flat lens is that by using meta-atoms of complex shapes, it not only provides the correct distribution of delay for a single color of light but also for a continuous spectrum of light,” Yu says. “And because they are so thin, they have the potential to drastically reduce the size and weight of any optical instrument or device used for imaging, such as cameras, microscopes, telescopes and even our eyeglasses.” Challenges still exist but the scientists are confident that they can solve the lens efficiency reduction due to increased reflection and scatter of light incident upon a flat lens. Read more at phys.org.

On another front, a team from Northwestern’s International Institute for Nanotechnology is developing tunable focusing in meta-lenses using nanotechnology. Now imagine a lens that could be programmed to form images at any 3D position going from single vision to multifocal. Consider the awesomeness of lenses that use nanotechnology to direct visible light to targeted focal points.

In a press release, Megan Feldman of Northwestern University states: “The Northwestern team built their lenses 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.”

It will be fascinating to see the changes that programmable nanotechnology brings to the future of eyeglasses.

Deborah Kotob
[email protected]
2020mag.com/education