Quantum phenomena have allowed scientists to develop lenses just three atoms thick, which are considered the thinnest lenses ever made.
Curiously, this innovative approach allows most wavelengths of light to pass through intact – a feature that offers great potential for fiber optic communications and devices such as augmented reality glasses.
Researchers from the University of Amsterdam in the Netherlands and Stanford University in the US, who invented the lens, say the innovation will advance research into such lenses as well as miniaturised electronic systems.
“This lens can be used in applications where it does not obstruct the view through the lens, but instead picks up only a portion of the light to gather information.” To tell Yorick van de Groop Nano Scientist At the University of Amsterdam.
Rather than using a curved surface of transparent material to bend the light through a process of refraction, the incoming waves are focused by a series of grooved edges. diffraction.
This technology: Fresnel Lens or Zone Plate Lenshas been used for centuries to make thin, lightweight lenses such as those used in lighthouses.
To give the technology a quantum boost, the team etched concentric rings into a thin layer called a semiconductor. Tungsten Disulfide (WS2). when W.S.2 When it absorbs light, its electrons move in such a precise way that they leave gaps that can be considered a kind of particle in themselves.
The electron and its “hole” together Forming something called an excitonIt has the property of increasing the efficiency of focusing light of specific wavelengths while allowing other wavelengths to pass through.
Depending on the size of the rings and the distance between them, the lens was able to focus the red light to a distance of one millimeter. Although the lens will still function at room temperature, its focusing ability becomes more efficient at lower temperatures..
The researchers next want to conduct further experiments to explore how to further manipulate the behavior of the excitons to improve the efficiency and performance of the lens. Future work could, for example, look at optical coatings that can be applied to other materials or changes in the charge.
“Excitons are very sensitive to the charge density in the material, so we can change the refractive index of the material by applying a voltage.” To tell Van de Group.
This study Nano Characters.
