Thinnest Optical Lens Created for Camera Systems with Potential for Wearable Devices

TapTechNews June 6 news, scientists have created the thinnest optical lens ever for camera systems, with a thickness of only 3 atoms. Researchers believe it will be particularly suitable for wearable devices like Google Glass and Meta's RayBan smart glasses.

This ultrathin flat lens, also known as a metalens, published in the journal NanoLetters, has an incredible thickness: only 0.0000006 millimeters or 0.6 nanometers, which is equivalent to the height of 3 atoms. It is known that researchers from the University of Amsterdam and Stanford University adopted a different approach from traditional optics to develop this lens.

According to TapTechNews, usually, traditional optical lenses use curved glass to bend and refract incoming light, making it refract again when it leaves, thus making objects appear closer than they actually are. But in recent years, scientists have been trying to replace these traditional glass optics with metasurfaces to solve its main problem: bulkiness. Currently, camera manufacturers are limited by the laws of physics, and multiple glass components take up a lot of space, and space is very precious on smartphones and wearable devices.

The metalens is designed to replace a full-sized optical device with a planar structure in a completely different way. Instead of using curved optics, they compress the system consisting of multiple glass optical systems into a smaller one, using nanoparticles and metasurfaces to bend the light.

This type of planar lens has not yet been applied to consumer imaging products, but researchers are still constantly pushing the boundaries of this concept. In this study, the researchers used a unique material called tungsten disulfide. Instead of using a curved glass lens, this metalens uses concentric rings of tungsten disulfide spaced apart, which is the same principle as a Fresnel lens, that is, using diffraction rather than refraction to focus the light.

The focusing efficiency of this ultraslim lens depends on the quantum effects inside tungsten disulfide, enabling this material to absorb specific wavelengths of light and re-emit them.

Scientists are particularly excited about another unique feature of this metalens: when the light passes through it, it produces a bright focus and most of the light is not affected. This might sound like a drawback, but it can actually be exploited.

This lens can be used in application scenarios where the lens field of view should not be disturbed but a small portion of the light can be used to collect information, which makes it very suitable for augmented reality smart glasses, Jorik van de Groep, one of the paper's authors, explained.

As mentioned earlier, the metalens has not yet reached the performance level that can be installed on consumer devices, but several companies including Metalenz and Canon are venturing into this field.