Contact lenses have become remarkably thin, but they pale in comparison to a groundbreaking new lens developed by scientists at Stanford University and the University of Amsterdam. This revolutionary lens measures just three atoms thick, making it the thinnest lens ever created.

Lenses function by collecting light, bending it, and focusing it towards a specific point. This process magnifies objects to correct vision, allows us to observe minute details through microscopes, and lets us see distant objects through telescopes. Typically, lenses are made of curved glass or other transparent materials such as hydrogels for contact lenses. However, these traditional designs can result in large, thick, and heavy lenses, especially when made of glass.

To address this, an alternative design known as the Fresnel lens was invented in the 19th century for use in lighthouses. Fresnel lenses employ a series of concentric circles to diffract light into a focal point, reducing thickness at the cost of some image clarity.

Pushing the boundaries of lens technology, scientists have now created a lens only 0.6 nanometers (nm) thick, equivalent to just three atoms. This achievement surpasses the previous record set in 2016, where the thinnest lens was 6.3 nm thick.

The new lens is constructed from concentric rings of tungsten disulphide. This material absorbs red light and re-emits it to a focal point 1 mm (0.04 inches) from the lens surface. The process involves forming short-lived quasiparticles called “excitons,” which decay and emit light. The lens specifically focuses red light, allowing other wavelengths to pass through unaffected, opening up fascinating potential applications.

“The lens can be used in applications where the view through the lens should not be disturbed, but a small part of the light can be tapped to collect information,” explained Jorik van de Groep, one of the study’s authors. “This makes it perfect for wearable glasses such as those used in augmented reality.”

The research team plans to explore whether this technique can be applied to create more complex coatings activated by small electrical signals.

By Impact Lab