Scientists at Stanford University and the University of Amsterdam developed the world’s thinnest lens, with a thickness of only three atoms, or 0.6 nm (nanometers). The previous record from 2016 was 10 times thicker, measuring 6.3 nm. This flat lens relies on quantum effects and has a possible application in future augmented reality glasses. Researchers include Ludovico Guarneri, Thomas Bauer, and Jorik van de Groep of the University of Amsterdam, together with colleagues from Stanford University in California.
The developed lens is made from concentric rings of tungsten disulphide (WS2) with gaps in between, which absorb red light and reemits it at a focal point 1 mm away from the surface. This is also called a ‘Fresnel lens’ or ‘zone plate lens’. Other wavelengths pass through unaffected, since the lens selectively focuses red light.
“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,” said Jorik van de Groep, an author of the paper. “This makes it perfect for wearable glasses such as for augmented reality.”
The researchers’ next steps include the utilization of this technique for more complex and multifunctional optical coatings that are activated by small electrical zaps. “Excitons are very sensitive to the charge density in the material, and therefore we can change the refractive index of the material by applying a voltage,” says Van de Groep in a statement.
The research is published in the Journal Nano Letters, titled “Temperature-Dependent Excitonic Light Manipulation with Atomically Thin Optical Elements”.
Article and Image Source: University of Amsterdam / Ludovica Guarneri and Thomas Bauer
